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Innovative developments in biofuels production from organic waste materials: A review
Abstract
Several organic wastes into energy conversion technologies were successful in addressing global challenges such as fossil fuel dependency, production cost optimization, waste management and emission control issues. The utilization of organic wastes for biofuels production is considered as a plausible approach for achieving better energy security, pollution control, process economics, sustainable production, and societal improvements. This work intends to comprehensively review all available technologies for producing biofuels from organic wastes. Besides, it presents a synoptic analysis of the status, prospects and challenges pertinent to each technology. Globally, liquid biofuels are gaining prominence because of their potential to reduce the consumption of fossil fuels in transportation and industrial sectors with comparable performance efficiencies. This review work demonstrates the superiority of biodiesel over other liquid biofuels through a comparative assessment of relevant factors. Some of the main constraints for commercial deployment of biodiesel production using organic wastes include higher production costs, higher energy consumption, longer reaction residence times, and unsystematic feedstock accumulation procedures. The process intensification methods implemented by various researchers to circumvent these biodiesel production challenges are also presented. Moreover, this article recommends a novel concept for intensification of biodiesel production from waste cooking oil using coalescer reactor along with a preliminary scrutiny for justifying further research potential of the approach.
... Algal biofuels are one such new transformative use in waste management that makes organic wastes a very useful energy resource [69]. ...
... Conventional waste-to-energy technologies are generally subject to significant constraints of efficiency and environmental factors, as seen in anaerobic digestion and incineration, for example. Algae provide a sustainable option by using by-products of waste, like agricultural runoff or even municipal organic waste, as nutrient sources for their growth [69]. Advantages of Algae Biofuels are as follows [70]: ...
Marine Biowaste, resulting from natural biological processes or human activities, seriously threatens the environment. Sources and impacts of Marine bio waste are discussed, classifying into two broad categories: Organic and Inorganic. Organic biowastes include those from aquaculture, agricultural runoff, industrial discharges, and urban runoff, while inorganic Biowaste include plastics, microplastics, metals, and synthetic materials. Those sources present pollution, habitat destruction, and impacts on marine species, which together drastically close the ecological balances. The role of zoology in Biowaste degradation is important, because it is concerned with the study of organisms responsible for breaking down organic wastes to make nutrients available. Both National and International legislation, such as UNCLOS and MMPA in the United States, provide a legal framework for the protection of Marine ecosystems from pollution and overexploitation. Advances in Marine biotechnology offer novel solutions to problems related to bio waste management, such as algal Biofuels and integrated waste management systems. Synthetically, biology trends, adaptation of climate change, and models of the circular economy provide potential solutions for future research and sustainable practices. This paper gives reasons for full strategies of Biowaste management with a view towards the preservation of Marine ecosystems and assurance of Environmental sustainability.
... The development of high-efficiency thermal treatment technology that converts organic solid wastes with low-grade energy into high-grade clean energy is of great significance in meeting the major needs of carbon neutrality, mitigating environmental pollution, and realizing the resource utilization of organic solid wastes [1][2][3][4]. Gasification is an effective treatment method to convert organic solid wastes into combustible gases, such as H 2 , CO, and CH 4 . However, traditional gasification technology has low efficiency and high energy consumption and is accompanied by the generation of tar as a by-product, which poses a threat to production safety. ...
The microwave chemical looping synergistic gasification characteristics of municipal solid waste polypropylene plastic and the organic solid waste water hyacinth are experimentally investigated in this study. In addition, the characterizations of oxygen carriers before and after the reaction are combined to analyze the evolution of the microscopic morphology of oxygen carriers and the changes in the relative contents of each valence state of Fe and O elements. The results show that an increase in the water hyacinth mixing ratio presents positive effects on tar cracking and a slight negative effect on syngas yield. At the water hyacinth mixing ratio of 75%, the cold gas efficiency and carbon conversion can reach maximum values of 77.64% and 69.9%, respectively. The H2 yield and H2/CO ratio in syngas can be also improved to 0.34 Nm3/kg and 1.62, respectively. In addition, a minimum tar yield of 0.133 g/g (fuel) can be obtained at this mixing ratio. Moreover, the addition of water hyacinth has a continuous increase effect on monocyclic aromatic hydrocarbon (MAH) products of tar, and a continuous decrease effect on naphthalene and bicyclic aromatic hydrocarbons (NAH) products. This work explores the synergistic properties of organic waste plastics and agroforestry wastes during microwave chemical looping gasification, which is a useful exploration for solving the environmental problems caused by waste materials and agroforestry wastes as well as realizing the resourceful utilization of solid wastes.
... Com o intenso aumento da demanda energética mundial, há uma necessidade de maior produção de combustível que atenda os fatores econômicos e energéticos da sociedade. Para controlar a poluição ambiental, é indispensável o desenvolvimento de novas tecnologias para produção de energia a partir de fontes renováveis (Stephen & Periyasamy, 2018). ...
Objective: Synthesize and characterize the heterogeneous catalyst MoO₃/Ce-SBA-15, to be applied in the transesterification reaction of soybean oil. Theoretical Framework: The molecular sieve SBA-15 is a mesoporous silica used as a support for the dispersion of active metals. Modification with cerium (Ce) enhances the textural properties, while doping with molybdenum oxide (MoO₃) increases the catalytic activity. This catalyst is applied in transesterification for the production of biodiesel, a renewable and efficient biofuel to replace fossil diesel. Method: Ammonium cerium nitrate was introduced along with the silica source in the synthesis gel, evaluating different Si/Ce molar ratios (10, 20). The obtained material was doped with MoO3 using the pore saturation method and evaluated in the transesterification reaction at different temperatures. Results and Discussion: Characterization analyses indicated that the longer crystallization time (48h) and the introduction of Ce into the structure improved the crystalline and textural properties of SBA-15. The presence of MoO₃ in its orthorhombic phase was confirmed by X-ray diffraction analysis. The maximum yield of methyl esters was 86.56% at 150°C using the 15MoO3/10Ce-SBA-15 catalyst. Research Implications: This research developed a new catalyst efficient in biodiesel production, contributing to the field of catalysis. Promoting advances in renewable energy and sustainability. Originality/Value: This study reports the influence of Ce as a structural promoter in the synthesis of a new catalyst (MoO3/Ce-SBA-15) to be applied in the transesterification reaction for biodiesel production.
... However, organic agriculture has better results than conventional agriculture, because it provides important environmental benefits, such as stopping the use of harmful chemical inputs and their spread in the environment (Gomiero et al., 2011). Organic waste to energy conversion technologies have been successful in solving global challenges such as fossil fuel dependence, optimization of production costs, waste management, emission control and sustainable production (Stephen & Periyasamy, 2018;Pantović et al., 2023). Life cycle assessment (LCA) is the most commonly used method for environmental impact assessment. ...
Bearing in mind the increasingly pronounced world challenges such as the growth of population on the world, climate changes and pandemics, there is an increasing emphasis on healthy and safe food, as well as environmental protection. Organic production achieves the best ecological advantages compared to all other agricultural production methods. However, its application is limited due to lower yields, which requires increasing productivity. The aim of the paper is to differentiate between conventional and organic inputs (resources) and their impact on agricultural production, economic and sustainable development. Ordinary Least Square (OLS) panel regression did not show a significant difference between conventional and organic inputs for agricultural production, where it is only important to increase the amount of inputs for higher production, while the increase in total factor productivity of inputs has a positive impact on the economic and sustainable development of the observed countries.
... Furthermore, the utilisation of biofuels (e.g., ethanol) in the transport sector may result in competition with food purposes [11]. Biofuels production from organic waste streams, such as municipal, kitchen and garden waste, was also investigated, but the higher production cost, energy consumption and longer residence time hinder their commercialisation [55]. ...
... In addition to biodiesel derived from biomass, there has been growing interest in producing modified biodiesel using low-cost oil feedstocks such as waste cooking oil (WCO) and tyre pyrolysis oil (TPO) [8,9] The use of WCO as a feedstock can significantly reduce biodiesel production costs, as it accounts for approximately 70-95 % of the total production cost [10,11]. TPO, synthesized via the thermal decomposition of waste tyres, has gained attention as a potential fuel blend with biodiesel. ...
... Además, cuando se entierran los residuos orgánicos, se genera una descomposición anaeróbica incontrolada que lleva a la producción de gases de efecto invernadero como metano (CH 4 ) y óxido nitroso (N 2 O). Es paradójico que en países donde día a día se pierden suelos por efecto de malas prácticas agrícolas y erosión, sea también donde menos se empleen los residuos orgánicos para generar abonos, haciendo circular el C que tanto se necesita para construir materia orgánica y mantener la producción agrícola empresas (Juul et al., 2013;Stephen and Periyasamy, 2018Elsayed et al., 2020Lim et al 2016Yong et al., 2016), (Figura 27). ...
Este libro es un manual práctico y didáctico, concebido como un tributo al profesor René Novo Sordo y como una herramienta para estudiantes y profesionales interesados en el campo de la microbiología ambiental. La obra abarca una amplia gama de temas relacionados con la presencia y el papel de los microorganismos en diversos entornos, desde el suelo y el agua hasta el aire. Destaca la diversidad de aplicaciones prácticas de la microbiología ambiental, como el desarrollo de biofertilizantes, el control de agentes patógenos y la evaluación de la calidad ambiental. El libro se estructura en 13 capítulos, cada uno de los cuales presenta una guía detallada para la realización de experimentos y análisis en el laboratorio. La inclusión de secciones dedicadas a materiales, metodología y referencias bibliográficas facilita la reproducción de los experimentos y la profundización en los temas tratados.
... OW energy recovery involves converting organic materials into usable energy forms, such as FW, agricultural residues, and animal waste. Forest, garden, sewage sludge, kitchen, solid biogenic, lignocellulosic, paper, farm, animal, and MSW containing primarily organic fractions are examples of OW [76]. Farming residues, agricultural wastes, pastoral wastes, and other green wastes are suitable for biofuel production in rural areas, while organic fractions of MSW are cost-effective and accessible in urban areas. ...
Purpose of Review
This review aims to critically assess contemporary challenges and prospective avenues in the sustainable handling and management of organic waste (OW), elucidating its environmental ramifications and exploring techno-economic perspectives. Reviewing current knowledge is synthesized to provide insights that will help develop innovative strategies and policies. These strategies and policies foster a holistic approach to mitigating the environmental impacts associated with OW while also addressing economic issues.
Recent Findings
The imperative of integrating advanced technologies and holistic environmental considerations into OW management is underscored by recent findings. Environmental footprints can be minimized through innovations such as decentralized processing systems. Further, understanding techno-economic dynamics reveals the potential for sustainable practices, indicating a shift towards circular economies. By integrating environmental and economic aspects of OW management, we can enhance waste management strategies.
Summary
The focus of this review is the significance of OW generation and management, including agricultural, municipal, and green sources, as well as microbial treatment platforms as a critical factor. The report discusses the benefits of anaerobic digestion and composting in OW treatment and the advantages of biotransformation in sustainable waste management through biofuel and biofertilizer (BioF) production. To maximize OW potential as a valuable resource for sustainable development, the review integrates environmental concerns with techno-economic perspectives. To unlock the full potential of OW as a valuable resource in sustainable development, this review addresses barriers. It advances future directions in OW handling and management by integrating environmental considerations with techno-economic perspectives.
Graphical Abstract
... As technology advances and the costs of renewable energy decrease, synthetic fuels become increasingly competitive in the energy market [47]. The absence of reliance on food crops, coupled with the potential to utilize waste materials and sustainably sourced biomass, mitigates concerns about increased food prices and competition with food production [48]. Synthetic fuels, therefore, represent a pragmatic and economically viable alternative to traditional biofuels. ...
This review offers a comprehensive overview of synthetic fuels as promising alternatives to conventional fossil fuels. The carbon-neutral potential of synthetic fuels, when produced using renewable energy and captured CO2, offering significant opportunities to mitigate CO2 emissions is discussed. Moreover, the efficiency of synthetic fuels is presented as they do not require dedicated agricultural land or substantial water resources, addressing concerns related to land use change and water scarcity associated with traditional biofuels. The economic viability of synthetic fuels is explored highlighting the advancements in technology and decreased renewable energy costs, coupled with their independence from food crops, mitigating concerns about potential impacts on food prices. Major investments by industry leaders like Porsche, HIF Global, and ExxonMobil, totalling $1 B, aimed at achieving an annual production of 550 M liters by 2026 are detailly covered. This study further extends emphasizing the scalability of synthetic fuel production through modular processes, enabling tailored facilities to meet regional demands and contribute to a decentralized and resilient energy infrastructure. Additionally, the "drop-in" nature of synthetic fuels, seamlessly compatible with existing fuel storage, pipelines, and pumps, is highlighted, facilitating a smooth transition without requiring extensive infrastructure changes. Challenges such as the current high cost of synthetic fuel production are acknowledged, necessitating supportive government policies and incentives for widespread adoption. Overall, synthetic fuels emerge as promising contenders in the pursuit of sustainable and adaptable energy solutions, with tangible benefits for the environment, economy, and existing energy infrastructure.
... Cellulosic biomass, such as agricultural waste and industrial waste, is typically an abundant and affordable supply that is accessible in nearly every country. Lignocellulosic agricultural waste is produced worldwide on an annual basis at a rate of 140 billion metric tonnes [5]- [7]. The development of "second generation" biomass-derived biofuels also faces numerous significant difficulties, including increasing biomass yield per hectare per year, maintaining sustainability while reducing agricultural inputs, and avoiding conflict with food production. ...
Biotechnology is one of the emerging fields that can add new and better application in a wide range of sectors like health care, service sector, agriculture, and processing industry to name some. This book will provide an excellent opportunity to focus on recent developments in the frontier areas of Biotechnology and establish new collaborations in these areas. The book will highlight multidisciplinary perspectives to interested biotechnologists, microbiologists, pharmaceutical experts, bioprocess engineers, agronomists, medical professionals, sustainability researchers and academicians. This technical publication will provide a platform for potential knowledge exhibition on recent trends, theories and practices in the field of Biotechnology.
... Cellulosic biomass, such as agricultural waste and industrial waste, is typically an abundant and affordable supply that is accessible in nearly every country. Lignocellulosic agricultural waste is produced worldwide on an annual basis at a rate of 140 billion metric tonnes [5]- [7]. The development of "second generation" biomass-derived biofuels also faces numerous significant difficulties, including increasing biomass yield per hectare per year, maintaining sustainability while reducing agricultural inputs, and avoiding conflict with food production. ...
The utilization of cellulosic biomass as a raw material for the production in biorefineries is widespread due to its cost-effectiveness, recyclability, and availability. However, existing biorefineries are still expensive and inefficient. This is largely due to the recalcitrant nature of lignocellulosic biomass, which necessitates expensive pretreatment processes to degrade the plant cell wall and lignocellulolytic enzymes to convert cellulose to glucose. Multi-omics and genome editing are possible approaches to lower the cost of operating biorefineries while also increasing the amount of energy extracted from biomass. It has been reported that genetic engineering is a successful method for enhancing agricultural plants' productivity, biomass yields, and specific traits. This chapter examines the development of various genetic modification approaches to modify plant cell walls. It proposes the application of genetic modification ofvarious plants, as a potential solution to the high costs and limited yields associated with biorefineries also utilizing agricultural waste as a feedstock for generation energy. Overall, the development of reliable and effective lignocellulosic biomass conversion procedures into bioproducts should be facilitated by the combination of various molecular biology and multi-omics approach that concurrently gather structural and chemical information regarding the biomass.
... Such studies have their specifics, as the range of fuel components is quite wide. [31][32][33][34][35][36][37] Fuel compositions based on coal processing waste like filter cake can significantly reduce the anthropogenic load on the environment. Filter cake is a wet substance resembling clay. ...
Experimental research findings are reported on the characteristics of surface transformation of droplets of promising fuel slurries in the air, as they move at subsonic velocities typical of combustion chambers of power plants. The main components of the fuels were water, coal processing waste, and coal. Typical shapes of droplets and the duration of their deformation cycles were identified. Droplets containing more than 70% of the solid phase remained practically undeformed. The lowest relative velocities of droplets leading to their fragmentation were determined. The key characteristics of secondary droplets (their number, sizes, velocities, and surface area of liquid) were calculated on the basis of the experimental findings. These characteristics were compared with those of initial droplets. Disruption conditions in the chosen range of the gas jet pressure (P ≤ 6 bars) can only be provided for fuel slurry droplets containing less than 60% of a coal component. The effect of a group of factors on deformation characteristics was identified. These include air jet and droplet velocities, droplet sizes, temperature, concentration, and type of components and additives. Approximation equations were derived for the mathematical description of the experimental data. Using certain criteria, the conditions necessary and sufficient for the disruption of water–fuel slurries on impact with an air jet were estimated.
... The waste-based materials are utilized for multifunctional applications such as energy storage [22][23][24], energy production [25,26], and green economy [27][28][29]. Utilizing waste materials in small-scale energy harvesting is another area of research that got a lot of attention with the development of wearable, portable electronic devices, small sensors, and the Internet of Things (IoT) [30][31][32][33]. ...
Recently, there has been a lot of focus on developing new waste-to-energy technologies because they help us to provide sustainable energy solutions for future generations. This review paper investigates an innovative waste-to-energy technology known as triboelectric nanogenerators (TENGs), which uses the electrostatic induction and contact electrification principles of physics. The underlying physics of TENG technology allows for a wide range of material choices for its fabrication; as a result, waste materials are utilized for energy production using TENGs. It comprehensively discusses how various types of waste, including plastic, electronic, medical, household, and biowaste, can be integrated into TENG technology for efficient energy production. Furthermore, various applications of waste-based TENGs are discussed in detail. Finally, we projected challenges and future directions for creating a sustainable, green energy landscape.
Graphical abstract
The review article presents a detailed exploration of triboelectric nanogenerators (TENGs) as novel waste-to-energy technologies that utilize waste materials.
... Industrydriven initiatives provide a vital role in endorsing biofuel process development using organic wastes. Some of the most well-established and commercially operational wastes into biofuels conversion technologies are: (i) ethanol production from agricultural residues, (ii) biogas production through anaerobic fermentation, and (iii) biodiesel production via the transesterification process (Sheppard 2008;Stephen and Periyasamy 2018;Zaldivar et al. 2001). ...
The dwindling supply of fossil fuels and environmental issues have raised awareness of alternative energy sources like biofuels. Microbial engineering, on the contrary, presents a viable approach for sustainable biofuel production considering the rising demand for renewable energy sources and the pressing need to mitigate climate change. This technique involves the strategic manipulation of microbes to maximize the production of biofuels, a renewable and sustainable substitute for fossil fuels. However, stepping up biofuel production poses numerous challenges, such as cost-effectiveness, sustainability, and regulatory concerns. Therefore, overcoming challenges of scaling up microbial biofuel production and creating cost-effective downstream processing are need of the hour. Through the exploration of concepts such as techno-feasibility, resource sustainability, resilience, and techno-economic analysis, it is conceivable that the development of technologies aligned with the principles of the circular economy can be achieved. In the present chapter the importance of metabolic engineering, synthetic biology, systems biology, and multi-omics for the design and optimization of microbial strains for biofuel production is reviewed and discussed. Also, a brief overview of the current state of microbial engineering for biofuel production globally is presented. The development of more effective and resistant microbial strains with the integration of an omics knowledge base for comprehension of systems-level knowledge of metabolic networks along with the use of novel bioprocessing methods for large-scale production have also been emphasised in this chapter.
... Para produzir biodiesel, os óleos e gorduras podem ser obtidos a partir de rejeitos de processos industriais. O uso de resíduo orgânico como matéria-prima para produção de biocombustíveis é uma nova abordagem para resolver questões de gestão de resíduos (STEPHEN, 2018). ...
As indústrias de beneficiamento de pescado geram grandes quantidades de resíduos durante o processo de produção. Nesse sentido, nota-se a importância do gerenciamento desses rejeitos, visto que, o descarte inadequado acarreta grande impacto ambiental. O objetivo do presente trabalho foi realizar a extração do óleo do resíduo de pescado e usá-lo como matéria-prima na produção de biodiesel por meio da rota de transesterificação. A partir disso, as amostras do óleo de pescado e do biodiesel foram submetidas as análises de acidez, massa específica, viscosidade cinemática, índice de refração e cromatografia. Os resultados mostraram que a acidez do biodiesel obtido foi de 2,64 KOH/g, porém a ANP estabelece o limite de acidez do biodiesel de 0,5 mg KOH/g. A composição de ácidos graxos do biodiesel evidenciou que o éster de ácido oleico (C18:1) é o ácido majoritário presente no biodiesel com valor de 38,658 (% área). Através do resultado da transesterificação foi possível transformar o óleo residual de pescado em 98,633(%) em éster, tornando-se uma alternativa válida para a matriz energética do Brasil.
... In areas where wood-based product manufacture is popular, forests and other lignocellulosic wastes are a viable choice because of their accessible availability and low pricing. For this reason, biopolymer manufacturing in various parts of the globe is primarily dictated by the accessibility and affordability of feedstocks [13]. Moreover, the conception of biorefinery broadens the potential for sustainably processing organic materials like niche crops and food scraps. ...
The current processes for producing polyhydroxyalkanoates (PHAs) are costly, owing to the high cost of cultivation feedstocks, and the need to sterilise the growth medium, which is energy-intensive. PHA has been identified as a promising biomaterial with a wide range of potential applications and its functionalization from waste streams has made significant advances recently, which can help foster the growth of a circular economy and waste reduction. Recent developments and novel approaches in the functionalization of PHAs derived from various waste streams offer opportunities for addressing these issues. This study focuses on the development of sustainable, efficient, and cutting-edge methods, such as advanced bioprocess engineering, novel catalysts, and advances in materials science. Chemical techniques, such as epoxidation, oxidation, and esterification, have been employed for PHA functionalization, while enzymatic and microbial methods have indicated promise. PHB/polylactic acid blends with cellulose fibers showed improved tensile strength by 24.45-32.08 % and decreased water vapor and oxygen transmission rates while PHB/Polycaprolactone blends with a 1:1 ratio demonstrated an elongation at break four to six times higher than pure PHB, without altering tensile strength or elastic modulus. Moreover, PHB films blended with both polyethylene glycol and esterified sodium alginate showed improvements in crystallinity and decreased hydrophobicity.
... Biofuels, extracted from starch, oil, and sugar contents present in plants and their waste, offer various benefits, including reduced greenhouse gas emissions, sustainable energy supply, positive economic impact, enhanced engine performance, and reduced dependence on foreign oil [36,37]. Besides these biomass-derived biofuels, modified biodiesel produced from waste materials has become increasingly appealing [38,39]. Waste tire disposal has become a growing concern, with billions of new tires produced annually, and only a fraction of them are recycled in the tire recycling sector. ...
The increasing global demand for alternative fuels as a replacement for fossil fuels has sparked a surge in the use of non-fossil fuel sources. While many alternative fuels already offer improved performance characteristics, ongoing research seeks to further enhance their quality. This particular study focuses on elevating fuel quality by introducing hydrogen into waste tire pyrolysis oil. To conduct the investigation, experimental tests were performed using three different fuel combinations: standard diesel, 15% (W15) waste tire pyrolysis oil blends, and 30% (W30) biodiesel blends. Additionally, each of these blends was enriched with 5 L/min of hydrogen gas. The experiments were conducted in a naturally aspirated, direct injection, four-cylinder, inline, four-stroke diesel engine, operating at various speeds of 1000 rpm, 1500 rpm, 2000 rpm, and 2500 rpm. The study assessed the parameters such as torque, power, specific fuel consumption, carbon monoxide, carbon dioxide, and nitrogen oxide emissions. Furthermore, this research explored the viability of utilizing waste tire pyrolysis oil blends with hydrogen as fuel in compression ignition engines without any modifications, as their fuel qualities were observed to be comparable to standard diesel fuel. Encouragingly, the results indicated that the addition of hydrogen to waste tire pyrolysis biodiesel improved the combustion process and led to a reduction in harmful gas emissions. Despite waste tyre pyrolysis oil possessing a lower heating value in comparison to diesel, the findings revealed that this heating value could be effectively enhanced by introducing hydrogen through the engine's inlet manifold. Among the blends tested, W15 emerged as a particularly promising alternative fuel for diesel engines due to its favorable performance and reduced environmental impact, as evidenced by lower carbon monoxide, carbon dioxide, and nitrogen dioxide emissions.
... Bioenergy conversion utilizing a range of biofuels is considered as one of the most prominent alternatives to fossil fuels due to its low carbon dioxide emission. Biofuels can be obtained from renewable energy resources including organic wastes as wheat straw, corn stover, citrus waste and forestry matter (Negro et al., 2018;Stephen and Periyasamy, 2018). Eventually, biofuels are biodegradable and environmentally friendly, contributing to sustainability. ...
This paper presents a bibliometric research of scientific documents on biofuel production from organic wastes extracted from the Web of Science (WoS) database. Original research and conference proceeding articles published until 2022 year were considered, which resulted in 773 documents. The objective of the study was to track evolutionary nuances and emerging trends of the topic, as well as upgrade knowledge in the area and help formulate scientific policies. The work concentrated on the most productive countries, authors and journals, as well as authors' keywords in documents relating to the biofuel conversion from biomass. The first paper on the field was published in 2004, and the publication number showed increasing trend with over 27% annual growth. The USA, followed by China demonstrated the highest publication and citation number. The thematic map analysis displayed the multidisciplinary nature of the topic, implying that the progress of several research domains is required for this technology. This is the first bibliometric review on biofuel from organic waste by microorganisms in the literature. The investigation results emphasize the need for further research in the area and also highlights the need for higher collaboration.
... Due to several reasons, there is a need to develop "drop-in" SAFs, which will be compatible with conventional oil-derived JFs in terms of composition, materials, and safety (Rahmes et al., 2009, Lew & Biddle, 2014Wang et al., 2016;Geleynse et al., 2018). Thus, industry and scientists look for the development of sustainable alternative JFs, which will be produced from renewable feedstock and will be used in existing jet engines interchangeably and without a need to make changes in jet engine construction (De Klerk, 2016;Neuling & Kaltschmitt, 2018;Stephen & Periyasamy, 2018). Today, several SAFs are allowed to be mixed with conventional JFs for up to 50% (Seber et al., 2014;Pires et al., 2018;Li et al., 2010). ...
The paper presents an analytical review of technological processes of alternative jet fuel production from alcohols and experimental results on the study of its physical-chemical properties. State-of-the-art in the sphere of civil aviation development within the framework of sustainable development and minimization of transport’s negative impact on the environment is presented. The development and implementation of sustainable aviation fuels are considered the main measure for reaching carbon-neutral growth. Two technologies of alcohol-to-jet fuel production are considered, and possible feedstock and processing pathways are presented. Physical-chemical properties of two kinds of alcohol-to-jet fuels are studied experimentally, as well as the properties of conventional jet fuels blended with alternative ones. It is shown that the physical-chemical properties of jet fuels blended with alcohol-to-jet component containing aromatics are very close to conventional jet fuels. All of the studied fuel blends with alcohol-to-jet components completely satisfy the requirements of specifications. Basing on the received results it is expected that alcohol-to-jet component containing aromatics may be successfully used for blending with conventional jet fuel and used as a drop-in fuel.
... Biofuels can now be produced at a reasonable cost due to the availability of cheap resources. Recent days, advanced renewable energy can be made from forest residues, agricultural lignocellulose, industrial wastes and algal biomass Stephen & Periyasamy, 2018). The general biofuel production routes from various feedstocks is presented in Table 1. ...
... Odor problem in handling waste. [39,40] Direct conversion of animal fat into biodiesel using transesterification and esterification process. ...
With raising concerns around the usage of fossil fuels and increasing waste there is an increased focus on finding alternate sources of energy to protect the environment as well as for sustainable development. Biomass waste has emerged as the new feedstock to produce renewable energy that can help in tackling climate changes and reduce dependence on traditional energy sources. Bioenergy production using wastes as feedstocks is an environmentally friendly and cost-effective process. However, deriving bioenergy from biomass waste streams requires pretreatment and/or innovative valorization strategies before being used as a feedstock in various conversion techniques such as thermo-chemical or biological processes. Most techniques require the application of heat to break down complex polymeric structures in the biowaste and make it more susceptible to hydrolysis. There is an increased focus on microwave heating as an alternative to conventional heating due to its various advantages such as speed, energy requirement and uniformity of heat dispersion. This review dives into a few of these aspects of microwaves and explores the application of microwaves as a standalone pretreatment technique as well as a co-pretreatment technique to enhance the performance of other thermo-chemical pretreatments. It also brings forward few of the challenges associated with the usage of microwaves and future research directions on tackling them.
... Biofuels can now be produced at a reasonable cost due to the availability of cheap resources. Recent days, advanced renewable energy can be made from forest residues, agricultural lignocellulose, industrial wastes and algal biomass Stephen & Periyasamy, 2018). The general biofuel production routes from various feedstocks is presented in Table 1. ...
Environmental Sustainability of Biofuels: Prospects and Challenges provides a comprehensive sustainability analysis of biofuels based on lifecycle analysis and develops various multi-dimensional decision-making techniques for prioritizing biofuel production technologies. Taking a transversal approach, the book combines lifecycle sustainability assessment, lifecycle assessment, lifecycle costing analysis, social lifecycle assessment, sustainability metrics, triple bottom lines, operational research methods, and supply chain designs for investigating the critical factors and critical enablers that influence the sustainable development of biofuel industry. This book will be a valuable resource for students, researchers and practitioners seeking to deepen their knowledge of biofuels as an alternative fuel.
It will equip researchers and policymakers in the energy sector with the scientific methodology and metrics needed to develop strategies for a viable sustainability transition.
... Biofuels can now be produced at a reasonable cost due to the availability of cheap resources. Recent days, advanced renewable energy can be made from forest residues, agricultural lignocellulose, industrial wastes and algal biomass Stephen & Periyasamy, 2018). The general biofuel production routes from various feedstocks is presented in Table 1. ...
The expanding human population along with industrialization, which results in increased fuel consumption, a decrease in fossil fuels, global warming and high fuel costs, prompted a search for an alternate solution for eco-innovation energy production. Protecting the environment and avoiding using chemicals to prepare for fuel production is necessary. Biofuel is the only eco-friendly and renewable solution to this problem of meeting energy demands. Biofuels include biodiesel, ethanol, bio-oil, hydrogen, methane, butanol and methanol. Plants, algae, municipal solid waste and microbial biomass are the most widely reputable sources of biofuels, which are environmentally and safe. Nanotechnology has the potential to have a huge impact on biofuel research, from nanomaterial processing to enzyme engineering for biofuel production. Identification of novel biofuel-producing organisms, optimization and improvement of their culture conditions, genetic engineering of biofuel-producing species, a thorough understanding of the metabolism of these organisms and effective strategies to mass culture these organisms to attain high biomass should be prioritized in the arena of biofuel research. This chapter discusses detail the methodology and technological advancements in biofuel generation and also highlights novel forms of biofuels.
... Biofuels can now be produced at a reasonable cost due to the availability of cheap resources. Recent days, advanced renewable energy can be made from forest residues, agricultural lignocellulose, industrial wastes and algal biomass Stephen & Periyasamy, 2018). The general biofuel production routes from various feedstocks is presented in Table 1. ...
Biofuels are one of the most promising approaches for reducing CO2 emissions in the transportation industry. However, due to numerous fundamental restrictions, such as a lack of raw materials, a low CO2 mitigation effect, a blending wall, and poor cost competitiveness, traditional plant-based biofuels (e.g., biodiesel, bioethanol) had a relatively low fraction of total transportation-fuel usage in 2016, under 4%. Advanced biofuels, such as drop-in, microalgal, and electro biofuels, especially those derived from inedible biomass, are seen as a possible answer to the problem of meeting rising biofuel demand. Recent advances in oxy-free hydrocarbon conversion via catalytic deoxygenation processes, oleaginous microalgae selection and lipid content increase, electrochemical biofuel conversion, and the diversification of useful products from biomass and intermediates are discussed in this study. Although the United States and the EU have different financial and approach motivating forces for biofuel production, markers of environmental sustainability have evolved from the updated research across the boundaries of politics. We categorized mentioned markers into six already set up characteristics of natural supportability, advertising depictions for each and connecting them to proposed universal guidelines for progressed biofuels. If ideal feedstock choice, administration, generation, and fuel transformation criteria are particularly sought after, progressed biofuel improvement can be a step toward naturally economic vitality. Even though devices for surveying natural supportability exist, they have not however been connected to progressed biofuels in a standardized way.
... Various sources can be used to produce biodiesel such as from waste cooking oil, plastics, and vegetable oil, animal fats. For example, by using waste cooking oil that has many disposal problems like water and soil pollution, human health concern; it can be used as an effective and cost efficient feedstock for biodiesel production [5]. Preparation of biodiesel from cooking oil and methanol by transesterification reaction using the heterogeneous catalyst will increase the reaction yield and minimize the methanol molar ratio because huge amount methanol required for reaction will involve an additional cost for the separation of biodiesel [6]. ...
Abundant of aluminum beverage cans are normally discarded after use have caused
considerable land pollution and environmental problems. This research is therefore aimed to synthesize alumina from aluminum can waste which is one of the most common kind of waste. The objective of this research is to synthesize and characterize alumina produced from aluminum can waste, and to be applied as catalyst support in the biodiesel production. In this study, the alumina from aluminum can waste was produced via Sol-gel method by varying the aging time. Characterization of alumina was performed by using FTIR, XRD, BET, and SEM-EDX. The synthesized alumina was used as catalyst support for potassium nitrate catalyst to be applied in biodiesel production by using transesterification reaction of cooking oil. The biodiesel produced was analyzed by using gas chromatography-mass spectrometry (GCMS) and FTIR. The experimental results revealed that the alumina powder synthesized at room temperature have high surface area which are suitable to be used as catalyst support of producing biodiesel. In conclusion, it has been demonstrated that it is possible to produce alumina from aluminum can waste that can be used as catalyst support for biodiesel production. From the GCMS and FTIR results, it was proven that biodiesel is produced.
... Organic wastes in energy conversion technologies are an active area of research aimed at reducing dependence on fossil fuels, optimizing production costs, improving waste management, and controlling emissions. Biochemical, physiochemical, and thermochemical processes produce different biofuels, such as bio-methanation, biohydrogen, biodiesel, ethanol, syngas, and coal-like fuels, which are studied by Stephen et al. [8]. Work is also being done on optimization, such as catalyst selection, reactor design, pyrolysis temperature, and other important factors [5]. ...
In this research, we develop machine learning models to predict future sensor readings of a waste-to-fuel plant, which would enable proactive control of the plant's operations. We developed models that predict sensor readings for 30 and 60 minutes into the future. The models were trained using historical data, and predictions were made based on sensor readings taken at a specific time. We compare three types of models: (a) a n\"aive prediction that considers only the last predicted value, (b) neural networks that make predictions based on past sensor data (we consider different time window sizes for making a prediction), and (c) a gradient boosted tree regressor created with a set of features that we developed. We developed and tested our models on a real-world use case at a waste-to-fuel plant in Canada. We found that approach (c) provided the best results, while approach (b) provided mixed results and was not able to outperform the n\"aive consistently.
Bioenergy is a versatile resource to overcome fossil fuel scarcity and energy crises. It can be feasibly derived from organic materials that are known as biomass. Although the sole utilization of biomass to obtain bioenergy is unreasonable; organic waste can be effectively up-scaled to generate biofuels that have potential applications. Due to the enormous population growth, vegetable waste from households, food supply chains, and packaging industries has drastically increased in recent years. Recycling this waste into green energy reduces greenhouse gas emissions and the limitations of finite fuels. Since they are non-edible waste materials with significant amounts of carbohydrates and lipids, they can be effectively degraded using biological approaches to generate biofuels such as bio-methane, bio-ethanol, and bio-diesels. The present book chapter deals with the classification of food waste, its characterization, and methods to convert them into bioenergy. It will also focus on the various applications of these valorized products and their efficacy. This chapter will give a thorough insight into the valuable features of bioenergy for developing a sustainable environment.
Sustainable biofuel production is an essential component of a broader strategy to address climate change, minimize greenhouse gas emissions, reduce water and energy consumption, and promote the use of non-food feedstocks and decrease dependence on fossil fuels. The current work explores the potential of sustainable technologies for biofuel production. It discusses the environmental impacts of traditional biofuel production methods and highlights the need for sustainable alternatives. The review deals with various sustainable technologies, including second-generation biofuels, algae-based biofuels, and waste-to-energy systems. The benefits and challenges of each technology are examined, and potential future developments are discussed. The range of sustainable technologies for biofuel production, including the use of genetically modified organisms to increase yield and efficiency, the development of new feedstocks such as microalgae and cellulosic biomass, and the implementation of advanced conversion processes such as hydrothermal liquefaction and gasification. Various sustainable technologies for biofuel production include advanced feedstock cultivation and harvesting methods, biorefinery processes that convert biomass into various biofuels and other valuable products, and efficient conversion processes that utilize waste streams and reduce emissions are discussed. It serves as a useful resource for researchers, practitioners, and policymakers interested in advancing in the field of bioenergy.
In practice, there are many unknown aspects to design a model for the use of organic solid waste in the city of Bogotá; Technical, financial, environmental and social aspects are necessary to obtain a sustainable use model that involves trade recyclers organizations picker organizations. For this research, a theoretical model was proposed using secondary information sources and international reference experiences. Also shown at level of Latin America, studies that have been conducted on composting and other applications that can be given to solid organic waste. Based on the model, a series of strategies were generated so that recyclers by trade could access and take advantage of organic waste produced in homes and other generators. One of the strategies consisted of generating a comprehensive management plan for organic solid waste that included: generation of organic waste, separation at the source, collection, transport and use with composting and vermiculture systems. With these tools was carried out a pilot test of the model in operation, in a vulnerable area adjacent to the city landfill. There, the model was applied with an organization of waste pickers and 200 houses in four neighborhoods. The waste separated at the source by the 200 houses were characterized, collected and transported by the recyclers' organization to a treatment plant where they were transformed through composting and vermiculture processes into organic compost and vermicompost fertilizers. In the follow-up process, the response of both the recyclers and the 200 families to the model in operation was evaluated.
This manuscript considers various conceptual elements of the sustainable use of organic solid waste by including recycling organizations for this type of waste and their interrelation in integrated management, circular and solidarity economy, as well as the theoretical aspects of applied sustainability in this context.
The excessive reliance on fossil fuels has resulted in an energy crisis, environmental pollution, and health problems, calling for alternative fuels such as biodiesel. Here, we review computational chemistry and machine learning for optimizing biodiesel production from waste. This article presents computational and machine learning techniques, biodiesel characteristics, transesterification, waste materials, and policies encouraging biodiesel production from waste. Computational techniques are applied to catalyst design and deactivation, reaction and reactor optimization, stability assessment, waste feedstock analysis, process scale-up, reaction mechanims, and molecular dynamics simulation. Waste feedstock comprise cooking oil, animal fat, vegetable oil, algae, fish waste, municipal solid waste and sewage sludge. Waste cooking oil represents about 10% of global biodiesel production, and restaurants alone produce over 1,000,000 m3 of waste vegetable oil annual. Microalgae produces 250 times more oil per acre than soybeans and 7–31 times more oil than palm oil. Transesterification of food waste lipids can produce biodiesel with a 100% yield. Sewage sludge represents a significant biomass waste that can contribute to renewable energy production.
Microbial electrosynthesis (MES) represents a recent alternative for direct/indirect upgrading of biogas streams in waste treatment plants. This study aims at evaluating the energy feasibility of different approaches including MES as a technology for biogas upgrading to obtain high quality biomethane. Scenario 2 is a MES system fed directly with raw biogas, and scenario 3 separates CO2 from the biogas stream for further transformation into biomethane, both scenarios improve the methane content up to 95%. In addition, the usable energy produced compared to the base scenario is 31.5–50.3% and 35.3–55.4% higher for scenario 2 and 3 respectively. Scenario 3 presents between 31–36% lower energy losses compared to scenario 2. Moreover, the proposed scenarios achieve similar values of total specific energy produced per tonne of CO2 generated close to fossil natural gas. However, more applied research is still needed to ensure large-scale MES performance.
Biofuel production using cyanobacteria aims to maintain the sustainability of an ecosystem with minimum impact on the environment, unlike fossil fuels, which cause havoc on the environment. The application of biofuel as an alternative energy source will not only help in maintaining a clean environment and improving air quality but also decrease harmful organic matter content from aquatic bodies. Cyanobacteria are valuable sources of many novel bioactive compounds, such as lipids and natural dyes, with potential commercial implications. One of the advantages of cyanobacteria is that their biochemical constituents can be modified by altering the source of nutrients and growth conditions. Careful changes in growth media and environmental conditions altering the quality and quantity of the biochemicals and yield capacity have been discussed and analyzed. In the present review, the challenges and successes achieved to date in the commercial production of biofuel and its application in the transportation industry are discussed. The authors also focus on different types of feedstocks obtained from biomass, especially from cyanobacterial species. This review also discusses the selection of appropriate cyanobacterial species with merits and demerits in the post-harvesting process. In sum, the current review provides insight into the use of organic bioresources to maintain a sustainable environment.
A microbial electrosynthesis cell (MES) is an electrochemical technique in which electrolithoautotrophic electroactive microbes fix carbon dioxide (CO2) to longer-chain volatile fatty acids (VFAs). The synthesis of VFAs from CO2 requires optimization to improve the MES performance for industrial feasibility. This work studied the effect of different parameters, such as pH, headspace gas pressure, ethanol concentration, electrolyte, and trace element concentrations, on VFA synthesis from CO2 that used mixed anaerobic consortia in serum bottles. The operational parameters were varied according to a central composite design (CCD) and response surface methodology (RSM). A global optimum for the response variables was determined. The optimum values of different operating factors to maximize VFA production that was obtained from the optimizations were 1.12 × 105 Pa pressure, pH 7.149, ethanol = 2,318.7 mg/L, three times the standard Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ) 300 electrolyte concentration and five times the standard DSMZ 300 trace elements concentration. The experimental study was validated in triplicate, which considered the optimal values. The rate of total VFA production that was obtained from the operational parameters experimental study was 43.7 ± 5.9 mg/L/day under this optimized condition, which agreed with the predicted value of 30.39 mg/L/day. For the media optimization, validation of the experimental study was conducted at the optimal values, and their experimental response was 79.75 ± 19.26 mg/L/day, and the predicted response was 75.89 mg/L/day for total VFA production rates.
Food waste (FW) poses significant risks to the sustainability of our food supply chains and systems. Considerable contributors to waste from the food supply chain include open markets, landfills, and marketplaces. Bio-circular-green (BCG) therefore aims to transform society by turning FW into value-added products using technology and innovation as a sensible solution to the problem of FW. The advancement of creative technologies and alternative agricultural practices have been presented in response to this rising issue. FW valorization provides a huge prospective solution both economically and environmentally. This chapter presents a comprehensive overview of the valorization of FW into biofuels, biochemicals, biofertilisers, and biopolymers. Current approaches and their challenges for bioprocessing FW to create concepts for BCG, with a focus on its contribution to income production as value-added products are covered. Challenges and constraints together with strategies for overcoming them are also presented along with future perspectives.
In the present era of the global energy crisis, the scientific community is constantly searching for alternate and sustainable energy sources. As the most sustainable energy material, biofuel comes out to be the most appropriate option. Different forms of biofuels include biodiesel, bioethanol, biogas, biobutanol, etc. Out of them, biodiesel is an eco-friendly renewable energy source derived from the trans-esterification of lipid-rich organic waste materials. The identical properties of biodiesel make it a good alternative to fossil fuel-based commercial diesel. Biodiesel is considered useful in various engines as it reduces the emission of greenhouse gases and increases engine lifespan. Biomass being a renewable energy source is a promising feedstock for biodiesel production. Therefore, biodiesel can be obtained from a wide variety of available feedstocks such as lipid-rich animal waste, waste cooking oil, non-edible oil, plant residues, algal biomass, etc. Recent advances in biodiesel production from waste biomass have received great attention from the scientific community as global fuel demand has been increasing day by day. Also, fossil fuel reservoirs are being depleted. Therefore, this chapter emphasized on utilization of different waste biomass for biodiesel production along with the latest technologies available for its better production and processing.
The work is devoted to the analysis of modern state and advance in implementation and use of sustainable aviation fuels. The most well-studied and widespread technologies as well as new ones are analyzed and compared. Among them we have studied fuels produced by Fischer-Tropsch (FT) process, hydrotreated esters and fatty acids, synthesized isoparaffins produced from hydroprocessed fermented sugars, alcohol to jet-synthesized paraffinic kerosene, alcohol to jet-synthesized kerosene with aromatics, catalytic hydrothermolysis fuel, hydroprocessed depolymerized cellulosic jet, hydrodeoxygenated synthesized kerosene, and hydrodeoxygenated synthesized aromatic kerosene. Feedstocks used for fuel production as well as physical-chemical properties of alternative aviation fuels are studied and compared. New challenges in the sphere of alternative aviation fuel production and use are faced out.KeywordsSustainable aviation fuelJet fuelDecarbonizationFeedstockFischer-Tropsch processHydrotreated esters and fatty acidsSynthesized isoparaffinsSynthesized paraffinic keroseneSynthesized kerosene with aromaticsCatalytic hydrothermolysisPropertiesEmissionCertification
Chinese herbal residue (CHR) is an association of renewable resource and hazardous waste, and high nitrogen content and low energy density are two primary obstacles to its efficient and clean thermal utilization. In this paper, acid-promoted hydrothermal was employed to probe the feasibility on CHR toward enhanced solid biofuel concerning upgradation and denitrogenation. A more excellent hydrothermal promoter (H2SO4) was demonstrated to upgrade and denitrogenate CHR with better energy (1.125) and nitrogen densities (0.586) at optimal conditions (160 °C, 0.5 N H2SO4), which could be attributed to the improved removal of oxygen, amino and ash during acid-promoted hydrothermal. Compared to raw feedstock or the conventional hydrochar, the acid-promoted hydrochar had enhanced compositional characteristics with higher heating value (21.00 kJ·mol⁻¹), lower nitrogen (1.44 wt%) and ash (11.03 wt%) contents, thus showing more stable combustion flame with a higher comprehensive combustion index of 4.861 × 10⁻⁸, a higher combustion stability index of 4979.342, lower combustion alkali index of 0.026, and less nitrogen gaseous pollutant emission. Thus, acid-promoted hydrothermal would be a promising way to convert CHR into much cleaner and higher-grade solid biofuel.
The conversion of biomass into chemicals and biofuels is an active research area as trends move to replace fossil fuels with renewable resources due to society’s increased concern towards sustainability. In this context, microwave processing has emerged as a tool in organic synthesis and plays an important role in developing a more sustainable world. Integration of processing methods with microwave irradiation has resulted in a great reduction in the time required for many processes, while the reaction efficiencies have been increased markedly. Microwave processing produces a higher yield with a cleaner profile in comparison to other methods. The microwave processing is reported to be a better heating method than the conventional methods due to its unique thermal and non-thermal effects. This paper provides an insight into the theoretical aspects of microwave irradiation practices and highlights the importance of microwave processing. The potential of the microwave technology to accomplish superior outcomes over the conventional methods in biodiesel production is presented. A green process for biodiesel production using a non-catalytic method is still new and very costly because of the supercritical condition requirement. Hence, non-catalytic biodiesel conversion under ambient pressure using microwave technology must be developed, as the energy utilization for microwave-based biodiesel synthesis is reported to be lower and cost-effective.
Biodiesel or fatty acid methyl ester (FAME) synthesis from sunflower oil and methanol using an immobilized lipase, an example of a liquid-liquid solid reaction, was studied in batch and various continuous reactor set-ups including the use of a centrifugal contactor separator (CCCS). The latter is an example of a highly intensified device, integrating liquid-liquid reactions and subsequent phase separations. An exploratory study in batch was performed to optimize enzyme and buffer concentrations. Close to quantitative biodiesel yields were obtained at 30°C when using 20% (w/w) of enzyme after a batch time of about 250 min. Subsequent continuous biodiesel synthesis was performed in a stirred tank reactor (CSTR) and a CCCS device. In the latter case, the immobilized enzyme was present in the annular, outer zone of the device. Average biodiesel yields in the CSTR and CCCS were similar (72%-mol respectively) when using a weight hourly space velocity (WHSV) of 3.3 and 3.03 h⁻¹, respectively, at 30°C. Cascade experiments were performed in a CSTR followed by a CCCS with the immobilized enzyme present in both reactors. The cascade was run for 9 h without any operation issues and an average FAME yield of 85%-mol was obtained. The advantage of the use of the cascade compared to a single CSTR is an improved yield combined with an efficient separation of the biodiesel layer and the glycerol. The biodiesel yield was about constant during the run, indicating that enzyme deactivation was negligible. The performance of the various reactor configurations were modelled successfully using standard balances for continuous reactors in combination with a kinetic model derived from the batch experiments.
This review highlights the utilization of kitchen wastes as substrates for bioethanol production. Kitchen wastes are commonly renewable, cheap and produced in large quantities daily. Kitchen wastes also contain a significant amount of organic matters particularly carbohydrates that can be converted into fermentable sugars for subsequent use in bioethanol fermentation. However, the advantages of kitchen wastes in biofuel production are indeed an untapped resource and poorly documented due to the challenges in the handling and disposal of kitchen wastes. Hence, a proper pretreatment and hydrolysis of the kitchen wastes by physical, chemical and biological methods is explored to increase the concentration of fermentable sugar released during the hydrolysis by enzymatic saccharification, thereby, improve the efficiency of the whole process. Furthermore, the advantages and drawbacks of each technology, challenges associated with feedstock handling and storage, government policies, and applications at commercial scale are critically discussed.
The challenges in the chemical processing industry today are environmental concerns, energy and capital costs. Catalytic distillation (CD) is a green reactor technology which combines a catalytic reaction and separation via distillation in the same distillation column. Utilization of CD in chemical process development could result in capital and energy savings, and the reduction of greenhouse gases. The efficacy of CD and the economic merits, in terms of energy and equipment savings, brought by CD for the production of biodiesel from waste oil such as yellow grease is quantified. Process flow sheets for industrial routes for an annual production of 10 million gallon ASTM purity biodiesel in a conventional process (reactor followed by distillation) and CD configurations are modeled in Aspen Plus. Material and energy flows, as well as sized unit operation blocks, are used to conduct an economic assessment of each process. Total capital investment, total operating and utility costs are calculated for each process. The waste oil feedstock is yellow grease containing both triglyceride and free fatty acid. Both transesterification and esterification reactions are considered in the process simulations. Results show a significant advantage of CD compared to a conventional biodiesel processes due to the reduction of distillation columns, waste streams and greenhouse gas emissions. The significant savings in capital and energy costs together with the reduction of greenhouse gases demonstrate that process intensification via CD is a feasible and new green process for the biodiesel production from waste oils.
Solid biomass and waste are major sources of energy.They account for about 80% of total primary energy
consumed in Nigeria. This paper assesses the biomass resources (agricultural, forest, urban, and other
wastes) available in Nigeria and the potential for biofuel production from first, second, third and fourth
generation biomass feedstocks.It reviews the scope of biomass conversion technologies tested within
the country and reports on the technology readiness level of each. Currently, most of the emerging
biofuels projects in Nigeria utilize first generation biomass feedstock for biofuel production and are
typically located many miles away from the petroleum refineries infrastructures. These feedstocks are
predominantly foodcrops and thus in competition with food production. With significant availability of
non-food biomass resources, particularly in the Niger Delta region of Nigeria, and the petroleum refineries
located in the same area, it is pertinent to consider expanding use of the petroleum refinery's
infrastructure to co-process non-food biomass into bio-intermediate oil for blending with petroleum.
This not only addresses the potential food versus fuel conflict challenging biofuel production in Nigeria,
but also reduces the cost of setting up new bio-refineries thus eliminating the transportation of ethanol
to existing petroleum refineries for blending. In view of this, it is recommended that further research be
carried out to assess the feasibility of upgrading existing refineries in Nigeria to co-process bio-based
fuels and petroleum products thus achieving the targets set by the Nigeria Energy Commission for
biofuel production in the country.
Roadmaps towards sustainable bioeconomy, including the production of biofuels, in many EU countries mostly rely on biomass use. However, although biomass is renewable, the efficiency of biomass production is too low to be able to fully replace the fossil fuels. The use of land for fuel production also introduces ethical problems in increasing the food price. Harvesting solar energy by the photosynthetic machinery of plants and autotrophic microorganisms is the basis for all biomass production. This paper describes current challenges and possibilities to sustainably increase the biomass production and highlights future technologies to further enhance biofuel production directly from sunlight. The biggest scientific breakthroughs are expected to rely on a new technology called "synthetic biology", which makes engineering of biological systems possible. It will enable direct conversion of solar energy to a fuel from inexhaustible raw materials: sun light, water and CO2. In the future, such solar biofuels are expected to be produced in engineered photosynthetic microorganisms or in completely synthetic living factories.
In this investigation, the potential of powdered activated carbon (PAC) derived from empty fruit bunch (EFB) precursor through pyrolysis method for chemical oxygen demand (COD) adsorption from biotreated palm oil mill effluent (POME) was extensively studied. The PAC was prepared and characterized using scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy and Brunauer–Emmett–Teller. The SEM microphotographs showed opened micropores existing in the PAC structure with a surface area of 886.2 m2/g. The FTIR spectra revealed the three major peaks exhibited by the surface of the activated carbon at exactly wavenumbers of 1737.61, 1365.10 and 1216.91 cm−1. This suggests the presence of some functional groups which can potentially enhance positive interactions between the adsorbent and the adsorbate. Design-Expert
® software (version 7.0.0) was employed for the statistical experimental design of a two-step optimization: factorial and response surface methodology. Maximum COD reduction of 84 % (227 ppm residual) was achieved from an initial concentration of 1387 ppm. This study being the first optimization process with the utility of EFB-based PAC in the treatment of the high-strength multicomponent biotreated POME; hence, the results could serve as requisite data for upscaling and/or future investigations in the utility of the precursor as a viable adsorbent.
An overview of the application of cavitation phenomenon for the intensification of chemical/physical processing applications has been presented here, discussing the causes for the observed enhancement and highlighting some of the typical examples. The important considerations required for efficient scale-up of the cavitational reactors and subsequent industrial applications have been depicted based on the work carried out as a result of sponsored projects at the Institute of Chemical Technology, Mumbai. Overall, it appears that the combined efforts of physicists, chemists and chemical engineers are required to effectively use cavitational reactors for industrial applications. Some recommendations for further work to be carried out in this area have also been mentioned, which should allow the exploitation of this technology on an industrial scale.
More than 10 million tons of biodiesel fuel (BDF) have been produced in the world from the transesterification of vegetable oil with methanol by using acid catalysts (sulfuric acid, H2SO4), alkaline catalysts (sodium hydroxide, NaOH or potassium hydroxide, KOH), solid catalysts and enzymes. Unfortunately, the price of BDF is still more expensive than that of petro diesel fuel due to the lack of a suitable raw material oil. Here, we review the best selection of BDF production systems including raw materials, catalysts and production technologies. In addition, glycerol formed as a by-product needs to be converted to useful chemicals to reduce the amount of glycerol waste. With this in mind, we have also reviewed some recent studies on the utilization of glycerol.
The ecological footprint and economic performance of the current suite of biofuel production methods make them insufficient to displace fossil fuels and reduce their impact on the inventory of Green House Gas (GHG) in the global atmosphere. Algae metabolic engineering forms the basis for 4th generation biofuel production which can meet this need. The first generation biofuels are known to be made from agricultural products such as corn or sugarcane. The second generation biofuels use all forms of (lingo)cellulosic biomass. The third and fourth generation of biofuel production involves “algae-to-biofuels” technology: the former is basically processing of algae biomass for biofuel production, while the latter is about metabolic engineering of algae for producing biofuels from oxygenic photosynthetic microorganisms. Our review focuses on the research achievement of metabolic engineering of algae for biofuel production. It is concluded that 4th generation biofuel production has introduced the “cell factory” concept in this field, and shifted the research paradigm. There still exists several technical bottlenecks in algae biofuel research and development, which can only be solved by the use of post-genome tools on these photosynthetic organisms.
New evidence on the thermal decomposition of fatty acid methyl esters during biodiesel synthesis in supercritical conditions is presented. Thermal decomposition products were detected chromatographically, by applying the UNE-EN 14105:2003 standard, as a broad single peak during the determination of glycerides in the reaction samples. These degradation products could be quantified chromatographically by the above standard because the area of the peak was proportional to the disappearance of the polyunsaturated fatty acid methyl esters, which contain two or more double bonds (methyl linoleate and linolenate), generated during biodiesel synthesis from soybean oil. In the experimental conditions tested, thermal decomposition reactions of these unsaturated fatty acid methyl esters began to appear at 300°C/26MPa, and were more intense as the temperature rose. For its part, the main saturated fatty acid methyl ester (methyl palmitate) generated during the reaction was hardly decomposed at all in the experimental conditions tested and only began to disappear at 350°C/43MPa.
The base catalyzed production of biodiesel (FAME) from sunflower oil and methanol in a continuous centrifugal contactor separator (CCS) with integrated reaction and phase separation was studied. The effect of catalyst loading (sodium methoxide), temperature, rotational frequency and flow rates of the feed streams was investigated. An optimized and reproducible FAME yield of 96% was achieved at a feed rate of 12.6mLmin−1 sunflower oil and a sixfold molar excess of MeOH (3.15mLmin−1) containing the catalyst (1wt% with respect to the oil). A jacket temperature of 75°C and a rotational frequency of 30Hz were applied. The productivity under those conditions (61 kgFAME mliquid−3 min−1) was slightly higher than for a conventional batch process. The main advantage is the combined reaction–separation in the CCS, eliminating the necessity of a subsequent liquid–liquid separation step.
With skyrocketing petroleum prices and war in the oil-producing nations of the Middle East, biofuels are increasingly touted as desirable alternatives to petroleum. But can they really help free us from a petroleum economy? How do they compete with conventional fuels and each other on a cost basis? What are the environmental impacts? Researchers at the University of Minnesota have published a wide-ranging study that offers some answers.
Currently, corn grain ethanol and soybean biodiesel are the two predominant alternative transportation fuels in the United States. Both can be used in conventional car and truck engines in blended form, and biodiesel can also be used in pure form (“B100”). Both are available at an increasing number of wholesale and retail locations across the nation. However, both require significant energy to produce, have their own environmental impacts, and could divert corn and soybeans from the nation’s food supply. Exactly what the energy balance and environmental impacts are and whether these fuels should be subsidized has been the subject of heated debate among scientists, policy makers, and the public.
Researchers from the University of Minnesota and St. Olaf College led by ecology professor G. David Tilman hoped to inform this debate by conducting a comprehensive analysis of the full life cycles of these biofuels. According to the study, published in the 25 July 2006 issue of the Proceedings of the National Academy of Sciences, a viable alternative fuel must meet four criteria: show superior environmental benefits over the fossil fuel it displaces, be economically competitive with that fossil fuel, be producible in sufficient quantities to make a meaningful impact on energy demands, and provide a net energy gain over the energy sources used to produce it.
Oscillatory flow reactors (OFRs) are a novel type of continuous reactor, consisting of tubes containing equally spaced orifice plate baffles. An oscillatory motion is superimposed upon the net flow of the process fluid, creating flow patterns conducive to efficient heat and mass transfer, whilst maintaining plug flow. Unlike conventional plug flow reactors, where a minimum Reynolds number must be maintained, the degree of mixing is independent of the net flow, allowing long residence times to be achieved in a reactor of greatly reduced length‐to‐diameter ratio. Many long residence time processes are currently performed in batch, as conventional designs of plug flow reactor prove to be impractical due to their high length‐to‐diameter ratios, which lead to problems such as high capital cost, large ‘footprint’, high pumping costs and, also control is difficult. The OFR allows these processes to be converted to continuous, thereby intensifying the process. The transesterification of various natural oils to form ‘biodiesel’ is a ‘long’ reaction, usually performed in batch. Conversion to continuous processing should improve the economics of the process, as the improved mixing should generate a better product (rendering the downstream separation processes easier), at lower residence time (reduction in reactor volume). These improvements can decrease the price of ‘biodiesel’, making it a more realistic competitor to ‘petrodiesel’. This paper shows that it is feasible to perform this reaction in an OFR at a lower residence time. The reaction was performed in a pilot‐scale plant, using rapeseed oil and methanol as the feedstocks, and NaOH as the catalyst.
© 2003 Society of Chemical Industry
Biodiesel can be a potential alternative to petroleum diesel, but its high production cost has impeded its commercialization in most parts of the world. One of the main drivers for the generation and use of biodiesel is energy security, because this fuel can be produced from locally available resources, thereby reducing the dependence on imported oil. Many countries are now trying to produce biodiesel from plant or vegetable oils. However, the consumption of large amounts of vegetable oils for biodiesel production could result in a shortage in edible oils and cause food prices to soar. Alternatively, the use of animal fat, used frying oils, and waste oils from restaurants as feedstock could be a good strategy to reduce the cost. However, these limited resources might not meet the increasing demand for clean, renewable fuels. Therefore, recent research has been focused the use of residual materials as renewable feedstock in order to lower the cost of producing biodiesel. Microbial oils or single cell oils (SCOs), produced by oleaginous microorganisms have been studied as promising alternatives to vegetable or seed oils. Various types of agro-industrial residues have been suggested as prospective nutritional sources for microbial cultures. Since the most abundant residue from agricultural crops is lignocellulosic biomass (LCB), this byproduct has been given top-priority consideration as a source of biomass for producing biodiesel. But the biological transformation of lignocellulosic materials is complicated due to their crystalline structure. So, pretreatment is required before they can be converted into fermentable sugar. This article compares and scrutinizes the extent to which various microbes can accumulate high levels of lipids as functions of the starting materials and the fermentation conditions. Also, the obstacles associated with the use of LCB are described, along with a potentially viable approach for overcoming the obstacles that currently preclude the commercial production of biodiesel from agricultural biomass.
This article is an up-to-date review of the literature available on the subject of liquid biofuels. In search of a suitable fuel alternative to fast depleting fossil fuel and oil reserves and in serious consideration of the environmental issues associated with the extensive use of fuels based on petrochemicals, research work is in progress worldwide. Researchers have been re-directing their interests in biomass based fuels, which currently seem to be the only logical alternative for sustainable development in the context of economical and environmental considerations. Renewable bioresources are available globally in the form of residual agricultural biomass and wastes, which can be transformed into liquid biofuels. However, the process of conversion, or chemical transformation, could be very expensive and not worth-while to use for an economical large-scale commercial supply of biofuels. Hence, there is still need for much research to be done for an effective, economical and efficient conversion process. Therefore, this article is written as a broad overview of the subject, and includes information based on the research conducted globally by scientists according to their local socio-cultural and economic situations.
The main problems of the conventional biodiesel production technology are high production costs and energy consumption, long residence time, and low efficiency. In order to overcome those problems and to improve the biodiesel production process from the ecological and economical points of view, intensive research activities on the development of new, sustainable technologies are undergone. Microreactors are known to increase the dispersion of two phases considerably as needed for the biodiesel reactants (alcohol and oil). This provides much higher interface area that by elimination of mass-transfer hindrance has shown to lead to shorter reaction time. On this background, this study gives (a) an overview of today’s industrial biodiesel production, (b) the vision of small-scaled, intensified (micro) flow reactors as integral element in translatable biodiesel factories, (c) the advantages and disadvantages of the lipase catalysed transesterification process in microreactors as chosen case of study, and (d) cost analysis of biodiesel production for the showcase estimating the performance of industrial-scale in enzyme packed-bed microreactors.
Techno-economic variables for advanced biofuels produced from lignocellulosic biomass have been scrutinized and combined with a newly developed transparent model for simulating the competitiveness between conventional and advanced biofuels for road transport in the medium to long term in Germany. The influence of learning effects and feedstock cost developments has been highlighted, including also gaseous fuels. Thorough sensitivity analyses were undertaken. Previously reported cost assumptions for advanced biofuels were found to have been too optimistic. The most cost-competitive biofuels for most of the time period remained conventional biodiesel and bioethanol, but the costs of these options and biomethane and Synthetic Natural Gas (bio-SNG) converged in the medium term and thus other factors will play a decisive role for market developments of biofuels. Feedstock cost uncertainties for the future remain a challenge for long-term planning, and low-cost short-rotation coppice may change the picture more than any other parameter. Of the advanced biofuels, bio-SNG was found significantly more cost-competitive and resource efficient than Fischer-Tropsch-diesel and lignocellulose-based ethanol, but still requiring a dedicated long-term policy. The results and the large sensitivities of biofuel competitiveness stress the need for more data transparency and for thorough sensitivity analyses of the results in similar system studies.
This study was aimed at performing a multi-objective fuzzy modeling and optimization of a low power, high frequency piezo-ultrasonic reactor for biodiesel production from waste cooking oil (WCO). To achieve this, three different fuzzy optimization methods were interfaced with adaptive neuro-fuzzy inference system (ANFIS) as modeling system to minimize the specific energy consumption of the reactor and to satisfy the ASTM standard on yield, i.e., conversion efficiency of >96.5%. Two ANFIS models were applied to correlate two output variables (conversion efficiency and specific energy consumption) individually with three input variables (reaction temperature, ultrasonic irradiation time, and methanol/oil molar ratio). The multi-objective optimization techniques included the fuzzy systems with independent, interdependent, and locally-modified interdependent objectives. Based on the results achieved, both ANFIS models excellently tracked the output parameters. Furthermore, the fuzzy system with locally-modified interdependent objectives outperformed the other two fuzzy systems in optimizing the transesterification process of the WCO. The optimal WCO transesterification process for biodiesel production in the developed reactor corresponded to the methanol/oil molar ratio of 6.1:1, ultrasonic irradiation time of 10 min, and reaction temperature of 59.5 °C in and led to a conversion efficiency of 96.63% and a specific energy consumption of 373.87 kJ/kg.
Biodiesel offers as an excellent alternative to the petro-based diesel fuel and can be derived from the reaction of vegetable/non-edible oils and/or animal fats with alcohols using the transesterification reaction. In the present study, hydrodynamic cavitation device as High Speed Homogenizer has been used for the intensified production of biodiesel for the first time. The efficacy of biodiesel production was observed to be dependent on the operational parameters viz. molar ratio, catalyst loading and operating temperature. The maximum yield of biodiesel obtained in the present work was 97% for waste cooking oil as starting material and 92.3% for fresh cooking oil under optimized conditions of reaction time of 120 min, molar ratio of methanol to oil as 12:1, 3% wt loading of KOH and temperature of 50°C. The study demonstrated that the application of cavitation offers the advantages as enhanced progress of reaction in reduced reaction time and improved separation. Overall, high speed homogenizer has been established to be a viable approach for intensified biodiesel production with possibly favourable economics.
Used frying oil (UFO), a waste produced in large volume each year worldwide, represents a potential resource for biofuel production rather than a disposal problem for modern society. Pyrolysis technique using microwave heating offers a promising approach for the conversion of UFO into biofuel products with improved properties. In this study, pyrolysis of UFO was performed by contacting with a bed of microwave absorbents heated by microwave radiation. The pyrolysis approach was examined using different materials as the reaction bed, comprising particulate carbon, activated carbon and mesoporous aluminosilicate (MCM-41). The use of particulate and activated carbon as the reaction bed provided a fast heating rate and extensive cracking capacity to pyrolyze the used oil, thus showing favorable features that could lead to short process time and less energy usage. This resulted in a production of a high yield of a biofuel product (up to 73 wt%) in a process taking less than 35 min. The biofuel showed a composition dominated by light C5-C20 aliphatic hydrocarbons with low amounts of oxygenated compounds (≤11%). In particular, the oil product obtained from activated carbon bed showed a low nitrogen content and was free of carboxylic acid and sulphur. The absence of carboxylic acids with low amounts of oxygenated compounds could reduce the formation of oxygenated by-products that could generate undesirable acidic tar or potentially hazardous sludge in the biofuel during storage. Combined with the detection of a high calorific value (46 MJ/kg) nearly comparable to diesel fuel, the biofuel shows great promise to be upgraded for use as a ‘cleaner’ fuel source with potentially reduced oxygenated by-products plus low or zero emissions of NOx and SOx during the use of the fuel in combustion process. This study also revealed that the use of activated carbon bed results in the highest energy recovery (88–90%) from the used frying oil. Our results demonstrated that the use of a microwave-heated reaction bed of activated carbon shows great potential as an improved and sustainable pyrolysis approach that is energy-efficient and timesaving for the recycling of used frying oil into a biofuel product with desirable properties. This pyrolysis approach provides an alternative to transesterification that avoids the use of solvents and catalysts, and thus could be developed further as a promising route to recycle various types of waste and biomass materials.
Due to the large amount of diesel fuel demands worldwide and the negative environmental and health impacts of its direct combustion, biodiesel production and consumption have been globally increasing as the best short-term substitute for mineral diesel. However, using edible and non-edible oil feedstocks for biodiesel production has led to several controversial issues including feedstock availability and cost, greenhouse gas (GHG) emission, land use changes (LUC), and fuel vs. food/feed competition. Fortunately, these problems can be effectively overcome using non-crop feedstocks. In this context, waste-oriented oils/fats have been proposed as the excellent options to produce biodiesel by overlooking the trivial collection/recycling costs. In this review article, a comprehensive collection plan followed by an elaborated integrated utilization strategy called “waste oil biodiesel utilization scenario” (WO-BUS) is proposed for Iran in order to achieve cost-effective and eco-friendly production/consumption of biodiesel. WO-BUS is adoptable by the countries with similar situations and infrastructures.
Biodiesel is a potential renewable and biodegradable fuel source comprising of fatty acid methyl esters (FAME). It is produced from transesterification reaction of animal fats and vegetable oils. It has been selected as a suitable alternative to conventional diesel fuel as it furnishes several advantages such as reduced environmental emissions, renewability and enhanced lubricity. However, biodiesel poses various tribological challenges. It has compatibility issues with certain materials, is inherent instable and highly corrosive in nature. Sporadic efforts have been carried out to understand the aforementioned issues, however significant knowledge has not been obtained until yet, especially on stability of biodiesel of biodiesel and its lubrication behaviour. In this review, different tribological aspects of biodiesel have been highlighted by critically analysing the recent available literature. Commencing from the basics of tribology, this review extends towards the properties of biodiesel and various aspects of metal contamination, moisture absorption, temperature and storage time. Tribological issues arising due to the usage of biodiesel and the use of additives in order to stabilize biodiesel and improve its tribological compatibility have been examined. Various factors affecting the stability and usage of biodiesel (long term/short term), properties have been discussed and improvements in refining technologies for biodiesel production have been summarized. Major concerns ascribed have been reviewed and possible remedies to improve the stability of biodiesel have also been included.
The mono-alkyl esters, most commonly the methyl esters, of vegetable oils, animal fats or other materials consisting mainly of triacylglycerols, often referred to as biodiesel, are an alternative to conventional petrodiesel for use in compression-ignition engines. The fatty acid esters that thus comprise biodiesel largely determine many important fuel properties. In turn, the composition of the biodiesel depends on the composition of the parent feedstock because feedstocks with widely varying fatty acid composition can be used for biodiesel production. The use of different feedstocks is also significant under aspects of increasing biodiesel supply and socio-economic issues. In this article, biodiesel production is briefly described, followed by a discussion of biodiesel fuel properties and the influence of varying fatty acid profiles and feedstocks. It is shown that the properties of biodiesel least influenced by minor components can be determined by a straightforward equation in which the properties of the biodiesel fuel are calculated from the amounts of the individual component fatty esters and their properties. Optimizing biodiesel composition is also addressed.
In the present study catalytic reforming of biogas was investigated to produce hydrogen rich syngas using solar energy source. The main objective of this work is to upgrade the quality of biogas using solar thermal energy. A foam type Ni based Al2O3 catalyst reactor was designed and developed for the catalytic reforming of biogas. Since dry reforming reaction of biogas being endothermic reaction, a 16 m2 solar concentrating collector was employed for supplying this heat. The performance of the reactor in terms of product gas composition at different temperatures using solar thermal energy was analysed. The results of the reforming reaction of biogas using solar energy have shown the conversion of both CH4 and CO2 into H2 and CO. The experimental results were compared with thermodynamic chemical equilibrium analysis. The flame study of biogas and syngas was done with gas samples. The in situ production of hydrogen rich syngas can also address the issue of hydrogen storage. The hydrogen rich syngas can be used in I. C. engine, fuel cell and methanol production applications.
Sodium aluminate is prepared from waste aluminium foils following an easy and low cost method. The crystalline NaAlO2 was found to have a uniform and highly porous morphology as revealed from the various characterization techniques. The developed catalyst showed high efficiency in the production of biodiesel from Jatropha oil. The reaction parameters were varied to find out suitable conditions for the transesterification reaction. The catalyst showed heterogeneity in methanol and is found to be reusable.
This study is aimed to investigate the combustion, performance and emission characteristics of a direct injection (DI) diesel engine, modified to operate with raw biogas - diesel dual fuel. The injection timing of diesel was varied from 23 oCA bTDC to 27.5 °CA bTDC in steps of 1.5 °CA, in the dual fuel operation. The results indicated that, dual fuel operation with the injection timing of 26 oCA bTDC gave an overall better result, than other injection timings. The brake specific carbon monoxide (BSCO) and brake specific hydrocarbon (BSHC) emissions were higher by about 2% and 10% respectively, than diesel operation, at full load. At full load, the smoke emission was lower by about 39% than diesel. The cylinder peak pressure was higher by about 14 bar and the brake specific fuel consumption (BSFC) was higher by about 25%, than diesel operation, at full load. At part load, the engine performance in the dual fuel operation was improved with advanced injection timing, with significant reduction in the exhaust emissions. The brake specific nitric oxide (BSNO) emission was higher with advanced pilot injections, than that of original injection timing but, it was about 16% lower than diesel, at full load.
In recent years, biodiesel has attracted significant attention from researchers, governments, and industries as a renewable, biodegradable, and non-toxic fuel. However, several feedstocks have been proven impractical or infeasible because of their extremely high cost due to their usage primarily as food resources. Waste cooking oil (WCO) is considered the most promising biodiesel feedstock despite its drawbacks, such as its high free fatty acid (FFA) and water contents. This review paper provides a comprehensive overview of the pre-treatment and the usage of WCO for the production of biodiesel using several methods, different types of reactors, and various types and amounts of alcohol and catalysts. The most common process in the production of biodiesel is transesterification, and using a methanol–ethanol mixture will combine the advantages of both alcohols in biodiesel production. In addition, this paper highlights the purification and analysis of the produced biodiesel, operating parameters that highly affect the biodiesel yield, and several economic studies. This review suggests that WCO is a promising feedstock in biodiesel production.
Biodiesel production from non-edible feedstocks is currently drawing much attention due to legitimate con-cerns about the effects of using edible oil for fuel. Pangium edule Reinw is a non-edible feedstock. Pangium is a tall tree native to the Micronesia, Melanesia and the mangrove swamps of South-East Asia. In this study, biodiesel produc-tion and characterization from P. edule oil was reported. The seeds were obtained from Bogor, Indonesia. The oil was found to have an acid value of 19.62 mg KOH/g oil. There-fore, a two-step acid–base-catalysed transesterification was used to produce biodiesel. This was followed by evaluat-ing the physical and chemical properties of biodiesel and its blends with diesel. It has been found that the determined properties of P. edule methyl ester indicate that the oil can be considered as a future biodiesel source. The most remarkable feature of P. edule is its cloud, pour and cold filter plugging points. This biodiesel yielded cloud, pour and cold filter plug-ging points of −6, −4 and −8 • C, respectively. This indicates the viability of using this biodiesel in cold countries. There- fore, it is suggested that more research should be conducted on P. edule for future biodiesel production. Abbreviations CCMO Crude Croton megalocarpus L. oil CIME Calophyllum inophyllum methyl ester CMOO Crude Moringa oleifera L. oil CN Cetane number COME Coconut methyl ester CPEO Crude Pangium edule oil CPO Crude palm oil CSO Crude soybean oil EPEO Esterified Pangium edule oil IV Iodine value JCME Jatropha curcas methyl ester MOME Moringa oleifera methyl ester PME Palm oil methyl ester PEME Pangium edule methyl ester SN Saponification number SME Soybean methyl ester
Current world energy usage is trying to gradually shift away from fossil fuels due to the concerns for the climate change and environmental pollutions. Liquid energy from renewable biomass is widely regarded as one of the greener alternatives to partially fulfil the ever-growing energy demand. Contemporary research and technology has been focussing on transforming these bio-resources into efficient liquid and gaseous fuels which are compatible with existing petrochemical energy infrastructure. Due to the wide range of properties and compositions from different types of biomass, there are ample of processing routes available to cater for different demands and requirements. In addition, they can produce multi-component products which can be further upgraded into higher value products. This conceives the idea of bio-refinery where different biomass conversion processes are incorporated and proceed simultaneously at one location. However, the underlying complexity in integrating different processes with varying process conditions will undoubtly incurs prohibitive cost. Consequently, process intensification plays an important role in minimizing both the capital and operating costs associated with process integration in bio-refineries. Recently, process intensification for biodiesel production has been developing rigorously due to increasing demand for cost-cutting measures. Supercritical fluid process allows biodiesel production to be performed without any addition of catalyst. Meanwhile, catalytic in situ or reactive extraction process for biodiesel production successfully combines the extraction and reaction phase together in a single processing unit. In this review, the important characteristics and recent progress on both of the intensification processes for biodiesel production will be critically analyzed. The prospects and recent advances of supercritical reactive extraction (SRE) process which integrates both of the processes will also be discussed. This review will also scrutinize on the methods for these processes to compliment future bio-refinery setup and more efficient utilizing of all of the products generated.
A cellular manufacturing process was developed for fabrication and assembly of a full-scale biodiesel microreactor capable of producing biodiesel fuel at the rate of 2.47 L/min and at a capacity of over 1.2 million liters of fuel per year. The scale-up of the microreactor was done through fabrication of over 14,000 individual microchannel laminae, and assembly of these laminae into a hierarchical system of modules and manifolds, thus duplicating many times over the intensification of the reaction rate per reactor volume that occurs in a single microchannel lamina. The work describes the design of the microreactor, the production process to fabricate and assemble the microreactor, the design of the manufacturing cell, and the testing of the microreactor to verify its performance.
The ever increasing worldwide demand for liquid and gaseous fuels along with overwhelming environmental concerns for greenhouse gas emissions have driven scientists and technologists to consider different alternative energy sources. In past decades, several biomass sources have been identified with increasing potential to be used as new alternative sources of energy - the “Biofuels”. The evolution of biofuels is classified into four different generations.
In this article an overview of the systematic evolution of different biofuel generations with their advantages and disadvantages has been presented. The advancements in technology, reduction in greenhouse gas emission and assessment of commercial production cost of each generation of biofuel have also been highlighted. Finally this review provides an outlook for a better future generation biofuel.
This work achieves continuous transesterification of soybean oil and methanol in a spinning disk reactor. The effects of the methanol-to-oil molar ratio, catalyst type, catalyst concentration, reaction temperature, flow rate, and rotational speed were investigated. Optimal yield of 96.9% was obtained with a residence time of 2–3 sec at a molar ratio of 6, potassium hydroxide concentration of 1.5 wt%, temperature of 60 °C, flow rate of 773 mL/min, and rotational speed of 2400 rpm. The production rate of 1.86 mol/min was high compared with that of other reactors for continuous transesterification process, indicating that a spinning disk reactor is a promising alternative method for continuous biodiesel production.
In this paper we describe an innovation for the intensified synthesis of biodiesel, exploiting a two-disk spinning disk reactor. The reactor comprises two flat disks, located coaxially and parallel to each other with a small gap between the disks. The upper disk is located on a rotating shaft while the lower disk is stationary. The feed liquids are introduced coaxially along the center line of each disk, with mixing commencing in the center of the inter-disk gap. The mixed phases flow radially outwards for ejection and coalescence on the inner containment wall of the reactor. Performance results in the reactor for the continuous synthesis of biodiesel from canola oil and methanol in the presence of a sodium hydroxide catalyst are presented. The effects of disk speed, volumetric flowrate, temperature, disk design, and the gap width between the two disks in the reactor were evaluated. The results show potentially a 20–40-fold decrease in residence time for the attainment of equilibrium compared with that determined for a stirred batch reactor used as a “control”. The mathematical modeling of the fluid flow conditions in the reactor is described. This provides further understanding of the potential importance of mixing in determining the reactor performance, pointing to some explanation of the relationship between conversion, flowrate, disk speed and geometry. The inter-disk gap, the reaction temperature, and the surface topology of the disks were the most important factors influencing reactor performance. Surprisingly, reactor performance increased as the inter-disk gap width was reduced. The results of the simulations gave an accurate fit with the experimental reactor performance data using true rate constants which were significantly higher than those reported in the literature. This suggests that some literature data may have not taken full account of mass transfer limitation during experimental determination of rate constants for biodiesel synthesis.
World energy crisis has become the foremost crucial topic in this new era. Unstable price of petroleum fuel in the world market and recent environmental concerns on gas emission during combustion have led to intensive search for alternative energy sources that are not only renewable but sustainable. Without doubt, one of the most important evolutions in the renewable energy sector is the development of biodiesel. Currently commercial biodiesel production is using methanol (non-renewable) as the main reactant to produce biodiesel due to its wide availability and low cost. However, biodiesel produced using methanol are not completely renewable as methanol can only be derived from petroleum fuel. Unfortunately, not much attention has been given on this issue. On the other hand, ethanol may emerge as a good solution to this problem as ethanol can be derived from renewable sources through fermentation process. The only constraint on the use of ethanol is its slow reaction rate in transesterification reaction and therefore resulted to energy inefficient biodiesel production process. Such limitations worsen if solid acid catalyst is used in the reaction. Thus, the aim of this present work is to introduce a simple mixed methanol–ethanol method to overcome these limitations and to produce biodiesel in a greener and sustainable manner. The effect of methanol to ethanol to oil molar ratio, reaction temperature, catalyst loading and reaction time towards biodiesel yield are discussed in detail. From this study, it was found that an optimum biodiesel yield of 81.4% can be attained at a relatively short reaction time of 1 h.
Global warming, high-energy demand and availability of new technologies are among the factors catalyzing the search for alternative sources of energy. Currently, there is renewed interest in obtaining energy from wastes hitherto meant for disposal. Increased costs of disposal and their attendant problems of heavy environmental loading are some aspects making the disposal option unattractive. These wastes are sources of energy and among the several sources of generating this energy are the waste-to-energy (WTE) categories with potentials for useable fuel production. The WTE materials are mainly used domestic waste oils (UDWOs), municipal solid waste (MSW), agricultural and industrial wastes. However, the latter wastes are not attractive as they consist of innumerable hazardous contaminants. The UDWOs are arguably a safe and cost effective source of useable fuel. Their conversion offers the merits of a reduction in greenhouse gas emission (GHG), enhancing fuel diversification and a qualitatively comparable energy output to fossil diesel fuels. Thus, UDWOs could significantly contribute towards achieving the 2020 and 2030 goals of substituting approximately 20% and 30% of petro-diesel with biofuels in US and EU, respectively. Moreover, attaining the forecasted annual production rate of 227 billion liters of biofuel by most active stakeholders in the biodiesel industry could be easily achieved.This review aims to analyze the performance of biodiesel fuels obtained from UDWO and to demonstrate the suitability of applying these fuels as substitutes to mineral diesel in various industries. Benefits of UDWO as a biodiesel feedstock were as well highlighted.
The accelerating and frequently fluctuating price of conventional diesel, together with growing environmental concerns has sparked renewed attention on the search for an alternative fuel. The awareness of the toxic effects related to the tailpipe emissions of vehicles has driven many countries to look for a less-polluted transportation fuel. In this regard, biodiesel (alkyl esters) from vegetable oils or animal fats via transesterification is regarded as the most viable alternative as a green fuel for diesel engines. Transesterification is a catalyzed process and, traditionally, homogeneous catalysts are employed. However, this type of catalyst is not able to be reused and requires tedious washing and separating steps, hence, stimulating the conception of heterogeneous-catalyzed transesterification. Despite the success of various heterogeneous catalysts, many are not viable for wide industrial usage as most of the catalysts are expensive and need additional preparation effort. Among them, CaO seems to have a promising place and the increasing research on CaO is self-evidence of its capability in catalyzing the reaction. Therefore, in this paper, various issues regarding CaO-catalyzed transesterification are reviewed. The diverse performance of CaO in neat, loaded and mixed forms, as well as a support for other catalyst systems, CaO reaction mechanism, CaO tolerance to low to moderate oil qualities and reaction conditions, the conformance of CaO-catalyzed biodiesel to key specifications and the future outlook and the challenges of the catalyst are suitably addressed.
Waste cooking oil (WCO) is the residue from the kitchen, restaurants, food factories and even human and animal waste which not only harm people’s health but also causes environmental pollution. The production of biodiesel from waste cooking oil to partially substitute petroleum diesel is one of the measures for solving the twin problems of environment pollution and energy shortage. In this project, synthesis of biodiesel was catalyzed by immobilized Candida lipase in a three-step fixed bed reactor. The reaction solution was a mixture of WCO, water, methanol and solvent (hexane). The main product was biodiesel consisted of fatty acid methyl ester (FAME), of which methyl oleate was the main component. Effects of lipase, solvent, water, and temperature and flow of the reaction mixture on the synthesis of biodiesel were analyzed. The results indicate that a 91.08% of FAME can be achieved in the end product under optimum conditions. Most of the chemical and physical characters of the biodiesel were superior to the standards for 0#diesel (GB/T 19147) and biodiesel (DIN V51606 and ASTM D-6751).
Fossil fuel resources are decreasing daily. As a renewable energy, biodiesel has been receiving increasing attention because of the relevance it gains from the rising petroleum price and its environmental advantages. This review highlights some of the perspectives for the biodiesel industry to thrive as an alternative fuel, while discussing opportunities and challenges of biodiesel. This review is divided in three parts. First overview is given on developments of biodiesel in past and present, especially for the different feedstocks and the conversion technologies of biodiesel industry. More specifically, an overview is given on possible environmental and social impacts associated with biodiesel production, such as food security, land change and water source. Further emphasis is given on the need for government’s incentives and public awareness for the use and benefits of biodiesel, while promoting policies that will not only endorse the industry, but also promote effective land management.
Transesterification reaction of rapeseed oil in supercritical methanol was investigated without using any catalyst. An experiment has been carried out in the batch-type reaction vessel preheated at 350 and 400°C and at a pressure of 45–65 MPa, and with a molar ratio of 1:42 of the rapeseed oil to methanol. It was consequently demonstrated that, in a preheating temperature of 350°C, 240 s of supercritical treatment of methanol was sufficient to convert the rapeseed oil to methyl esters and that, although the prepared methyl esters were basically the same as those of the common method with a basic catalyst, the yield of methyl esters by the former was found to be higher than that by the latter. In addition, it was found that this new supercritical methanol process requires the shorter reaction time and simpler purification procedure because of the unused catalyst.
Biodiesel has high potential as a new and renewable energy source in the future, as a substitution fuel for petroleum-derived diesel and can be used in existing diesel engine without modification. Currently, more than 95% of the world biodiesel is produced from edible oil which is easily available on large scale from the agricultural industry. However, continuous and large-scale production of biodiesel from edible oil without proper planning may cause negative impact to the world, such as depletion of food supply leading to economic imbalance. A possible solution to overcome this problem is to use non-edible oil or waste edible oil (WEO). In this context, the next question that comes in mind would be if the use of non-edible oil overcomes the short-comings of using edible oil. Apart from that, if WEO were to be used, is it sufficient to meet the demand of biodiesel. All these issues will be addressed in this paper by discussing the advantages and disadvantages of using edible oil vs. non-edible vs. WEO as feedstock for biodiesel production. The discussion will cover various aspects ranging from oil composition, oil yield, economics, cultivation requirements, land availability and also the resources availability. Finally, a proposed solution will be presented.
As an alternative fuel, biodiesel has been accepted because it is produced from renewable resources. There are some technical challenges facing biodiesel production via transesterification, which include long residence times, high operating cost and energy consumption, and low production efficiency. In recent years, studies on biodiesel synthesis have focused on development of process intensification technologies to resolve some of these issues. This contribution will present a brief review of some of technologies being developed and includes description of some of the types of novel reactors and relevant coupled reaction/separation processes. These technologies enhance reaction rate, reduce molar ratio of alcohol to oil and energy input by intensification of mass transfer and heat transfer and in situ product separation, thus achieve continuous product in a scalable unit. Some of these technologies have been commercialized successfully.
In this paper, integration possibilities for production of biodiesel and bioethanol using a single source of biomass as a feedstock (oil palm) were explored through process simulation. The oil extracted from Fresh Fruit Bunches was considered as the feedstock for biodiesel production. An extractive reaction process is proposed for transesterification reaction using in situ produced ethanol, which is obtained from two types of lignocellulosic residues of palm industry (Empty Fruit Bunches and Palm Press Fiber). Several ways of integration were analyzed. The integration of material flows between ethanol and biodiesel production lines allowed a reduction in unit energy costs down to 3.4%, whereas the material and energy integration leaded to 39.8% decrease of those costs. The proposed integrated configuration is an important option when the technology for ethanol production from biomass reaches such a degree of maturity that its production costs be comparable with those of grain or cane ethanol.
Mixed oxides of TiO(2)-MgO obtained by the sol-gel method were used to convert waste cooking oil into biodiesel. Titanium improved the stability of the catalyst because of the defects induced by the substitution of Ti ions for Mg ions in the magnesia lattice. The best catalyst was determined to be MT-1-923, which is comprised of an Mg/Ti molar ratio of 1 and calcined at 923 K, based on an assessment of the activity and stability of the catalyst. The main reaction parameters, including methanol/oil molar ratio, catalyst amount, and temperature, were investigated. The catalytic activity of MT-1-923 decreased slowly in the reuse process. After regeneration, the activity of MT-1-923 slightly increased compared with that of the fresh catalyst due to an increase in the specific surface area and average pore diameter. The mixed oxides catalyst, TiO(2)-MgO, showed good potential in large-scale biodiesel production from waste cooking oil.