added an update
Efforts to increase access to primary health care are ongoing in Sudan. Many health facilities were established and many health personnel were trained. As time passes, there is great concern about the sustainability as well as the effectiveness of these services due to lack of efficient local health system. With the establishment of federal system, Sudan was divided into states and localities with division of responsibilities between different levels. Health, in most of the cases, is the responsibility of states and localities. Tremendous efforts are going on to develop the capacity of states with few attempts to develop the local health system. This short communication aims to through light on the experience of health area policy in Sudan. The concentration will be on the experience of Umshanig health area (1982-1986), East Gezira which is the first in Sudan. Though the time was change, still lessons can be obtained from this experience. The health system in Sudan: Currently the administrative system in Sudan is the three-tier system: national, state and locality. This differs from the system during the 1980s in Sudan where there were no states. Instead there were regions (containing 2-3 states) and a province (almost equal to current states). The health system follows the same pattern now and in the past. The difference is in the number of health facilities and the personnel at health facilities level. There was a general hospital (at the province level with specialists), rural hospitals (each with only one general practitioner), limited number of health centers (run by medical assistants) and a number of dispensaries and health units which are run by certified nurses or health aides.
The development and recycling of biomass production can partly solve issues of energy, climate change, population growth, food and feed shortages, and environmental pollution. For instance, the use of seaweeds as feedstocks can reduce our reliance on fossil fuel resources, ensure the synthesis of cost-effective and eco-friendly products and biofuels, and develop sustainable biorefinery processes. Nonetheless, seaweeds use in several biorefineries is still in the infancy stage compared to terrestrial plants-based lignocellulosic biomass. Therefore, here we review seaweed biorefineries with focus on seaweed production, economical benefits, and seaweed use as feedstock for anaerobic digestion, biochar, bioplastics, crop health, food, livestock feed, pharmaceuticals and cosmetics. Globally, seaweeds could sequester between 61 and 268 megatonnes of carbon per year, with an average of 173 megatonnes. Nearly 90% of carbon is sequestered by exporting biomass to deep water, while the remaining 10% is buried in coastal sediments. 500 gigatonnes of seaweeds could replace nearly 40% of the current soy protein production. Seaweeds contain valuable bioactive molecules that could be applied as antimicrobial, antioxidant, antiviral, antifungal, anticancer, contraceptive, anti-inflammatory, anti-coagulants, and in other cosmetics and skincare products.
Metal-organic frameworks are porous polymeric materials formed by linking metal ions with organic bridging ligands. Metal-organic frameworks are used as sensors, catalysts for organic transformations, biomass conversion, photovoltaics, electrochemical applications, gas storage and separation, and photocatalysis. Nonetheless, many actual metal-organic frameworks present limitations such as toxicity of preparation reagents and components, which make frameworks unusable for food and pharmaceutical applications. Here, we review the structure, synthesis and properties of cyclodextrin-based metal-organic frameworks that could be used in bioapplications. Synthetic methods include vapor diffusion, microwave-assisted, hydro/solvothermal, and ultrasound techniques. The vapor diffusion method can produce cyclodextrin-based metal-organic framework crystals with particle sizes ranging from 200 nm to 400 μm. Applications comprise food packaging, drug delivery, sensors, adsorbents, gas separation, and membranes. Cyclodextrin-based metal-organic frameworks showed loading efficacy of the bioactive compounds ranging from 3.29 to 97.80%.
Plastic and biomass waste pose a serious environmental risk; thus, herein, we mixed biomass waste with plastic bottle waste (PET) to produce char composite materials for producing a magnetic char composite for better separation when used in water treatment applications. This study also calculated the life cycle environmental impacts of the preparation of adsorbent material for 11 different indicator categories. For 1 functional unit (1 kg of pomace leaves as feedstock), abiotic depletion of fossil fuels and global warming potential were quantified as 7.17 MJ and 0.63 kg CO2 equiv for production of magnetic char composite materials. The magnetic char composite material (MPBC) was then used to remove crystal violet dye from its aqueous solution under various operational parameters. The kinetics and isotherm statistical theories showed that the sorption of CV dye onto MPBC was governed by pseudo-second-order, and Langmuir models, respectively. The quantitative assessment of sorption capacity clarifies that the produced MPBC exhibited an admirable ability of 256.41 mg g-1. Meanwhile, the recyclability of 92.4% of MPBC was demonstrated after 5 adsorption/desorption cycles. Findings from this study will inspire more sustainable and cost-effective production of magnetic sorbents, including those derived from combined plastic and biomass waste streams.
It is critical to develop carbon removal projects that are both effective and financially viable. Herein, we investigated the carbon removal potential of an industrial biochar system in Spain. This study is the first to assess the techno-economic-environmental impact of large-scale olive tree pruning residue pyrolysis for atmospheric carbon removal, using an integrated assessment framework that is based on current market dynamics. Production optimization using response surface methodology (RSM) was carried out, aiming to maximize yield, production throughput and stable carbon content while prioritizing stability. It was determined that optimized biochar production was attained at 650 °C and 15 min residence time. Furthermore, a biochar plant with a biomass processing capacity of 6.5 tonnes-per-hour was designed for further analysis. A thermodynamic model was developed using Advanced System for Process Engineering (ASPEN Plus) software, and the process was determined to be self-sufficient with the availability of surplus energy. Moreover, a life cycle assessment (cradle-to-grave) revealed that approximately 2.68 tCO2e are permanently removed from the atmosphere per tonne of biochar produced, after accounting for the carbon footprint of the entire process. This corresponds to a carbon removal capacity of 3.26 tCO2e per hour and the removal of approximately 24,450 tCO2e annually. The economic assessment revealed that the project is profitable; however, profitability is sensitive to pricing of the carbon removal service and biochar. A project internal rate of return (IRR) of 22.35% is achieved at a price combination of EUR 110/tonne CO2e removal and EUR 350/tonne biochar, and a feedstock cost of 45 EUR/tonne (delivered with 20% moisture content), where service and product pricing are both within the lower bound of market pricing. If the project was exclusively designed to offer a carbon removal service, a minimum price of EUR 206/tonne CO2e removal is required to achieve project profitability, based on the same feedstock cost. The findings of this study demonstrate the viability of immediately deploying large-scale biochar-based carbon removal via pyrolytic conversion of olive tree pruning residues to address the climate crisis.
This study investigated the performance of supported Ni catalysts in the utilization of greenhouse gases like CO2 and CH4 via dry reforming. The support SBA-15 was impregnated first with Sc at different loadings (0.5, 1, and 3 wt.%) and then with Ni (5 wt.%). The catalysts were first tested up to 8 h on stream with stoichiometric feed as well as methane in excess. The as-prepared catalysts were characterized using BET, XRD, TPR, CO2-TPD, XPS, TGA, and TEM. This is in accordance with the surface area measurement, XRD, and TEM data. The Ni added to Sc-SBA-15 appeared to interact with both the support and Sc as the intensity and reduction temperature of the Sc promoted catalysts increased relatively to the unpromoted sample depending on Sc content. The catalyst with 0.5 wt.% Sc loading led to the highest conversion and the lowest relative activity loss. The CH4 and CO2 conversions, on average, were 78 and 86 %, respectively, at the end of the runs at 750 °C. The final H2/CO ratio was 0.99, which is a good value compared to many literature catalysts. This catalyst also showed relatively constant CH4 and CO2 conversions over 80 h on stream. Increasing the Sc loading above 0.5 wt.% was not beneficial in terms of activity.
Climate change and the unsustainability of fossil fuels are calling for cleaner energies such as methanol as a fuel. Methanol is one of the simplest molecules for energy storage and is utilized to generate a wide range of products. Since methanol can be produced from biomass, numerous countries could produce and utilize biomethanol. Here, we review methanol production processes, techno-economy, and environmental viability. Lignocellulosic biomass with a high cellulose and hemicellulose content is highly suitable for gasification-based biomethanol production. Compared to fossil fuels, the combustion of biomethanol reduces nitrogen oxide emissions by up to 80%, carbon dioxide emissions by up to 95%, and eliminates sulphur oxide emission. The cost and yield of biomethanol largely depend on feedstock characteristics, initial investment, and plant location. The use of biomethanol as complementary fuel with diesel, natural gas, and dimethyl ether is beneficial in terms of fuel economy, thermal efficiency, and reduction in greenhouse gas emissions.
Solid wastes from domestic, industrial and agricultural sectors cause acute economic and environmental problems. These issues can be partly solved by anaerobic digestion of wastes, yet this process is incomplete and generates abundant byproducts as digestate. Therefore, cultivating mixotrophic algae on anaerobic digestate appears as a promising solution for nutrient recovery, pollutant removal and biofuel production. Here we review mixotrophic algal cultivation on anaerobic waste digestate with focus on digestate types and characterization, issues of recycling digestate in agriculture, removal of contaminants, and production of biofuels such as biogas, bioethanol, biodiesel and dihydrogen. We also discuss applications in cosmetics and economical aspects. Mixotrophic algal cultivation completely removes ammonium, phosphorus, 17β-estradiol from diluted digestate, and removes 62% of zinc, 84% of manganese, 74% of cadmium and 99% of copper.
A photographic record of the construction of branches of the National Bank of Greece throughout the country
The world is experiencing an energy crisis and environmental issues due to the depletion of fossil fuels and the continuous increase in carbon dioxide concentrations. Microalgal biofuels are produced using sunlight, water, and simple salt minerals. Their high growth rate, photosynthesis, and carbon dioxide sequestration capacity make them one of the most important biorefnery platforms. Furthermore, microalgae's ability to alter their metabolism in response to environmental stresses to produce relatively high levels of high-value compounds makes them a promising alternative to fossil fuels. As a result, microalgae can signifcantly contribute to long-term solutions to critical global issues such as the energy crisis and climate change. The environmental benefts of algal biofuel have been demonstrated by signifcant reductions in carbon dioxide, nitrogen oxide, and sulfur oxide emissions. Microalgae-derived biomass has the potential to generate a wide range of commercially important high-value compounds, novel materials, and feedstock for a variety of industries, including cosmetics, food, and feed. This review evaluates the potential of using microalgal biomass to produce a variety of bioenergy carriers, including biodiesel from stored lipids, alcohols from reserved carbohydrate fermentation, and hydrogen, syngas, methane, biochar and bio-oils via anaerobic digestion, pyrolysis, and gasifcation. Furthermore, the potential use of microalgal biomass in carbon sequestration routes as an atmospheric carbon removal approach is being evaluated. The cost of algal biofuel production is primarily determined by culturing (77%), harvesting (12%), and lipid extraction (7.9%). As a result, the choice of microalgal species and cultivation mode (autotrophic, heterotrophic, and mixotrophic) are important factors in controlling biomass and bioenergy production, as well as fuel properties. The simultaneous production of microalgal biomass in agricultural, municipal, or industrial wastewater is a low-cost option that could signifcantly reduce economic and environmental costs while also providing a valuable remediation service. Microalgae have also been proposed as a viable candidate for carbon dioxide capture from the atmosphere or an industrial point source. Microalgae can sequester 1.3 kg of carbon dioxide to produce 1 kg of biomass. Using potent microalgal strains in efcient design bioreactors for carbon dioxide sequestration is thus a challenge. Microalgae can theoretically use up to 9% of light energy to capture and convert 513 tons of carbon dioxide into 280 tons of dry biomass per hectare per year in open and closed cultures. Using an integrated microalgal biorefnery to recover high-value-added products could reduce waste and create efficient biomass processing into bioenergy. To design an efcient atmospheric carbon removal system, algal biomass cultivation should be coupled with thermochemical technologies, such as pyrolysis
In the context of climate change and the circular economy, biochar has recently found many applications in various sectors as a versatile and recycled material. Here, we review application of biochar-based for carbon sink, covering agronomy, animal farming, anaerobic digestion, composting, environmental remediation, construction, and energy storage. The ultimate storage reservoirs for biochar are soils, civil infrastructure, and landfills. Biochar-based fertilisers, which combine traditional fertilisers with biochar as a nutrient carrier, are promising in agronomy. The use of biochar as a feed additive for animals shows benefits in terms of animal growth, gut microbiota, reduced enteric methane production, egg yield, and endo-toxicant mitigation. Biochar enhances anaerobic digestion operations, primarily for biogas generation and upgrading, performance and sustainability, and the mitigation of inhibitory impurities. In composts, biochar controls the release of greenhouse gases and enhances microbial activity. Co-composted biochar improves soil properties and enhances crop productivity. Pristine and engineered biochar can also be employed for water and soil remediation to remove pollutants. In construction, biochar can be added to cement or asphalt, thus conferring structural and functional advantages. Incorporating biochar in biocomposites improves insulation, electromagnetic radiation protection and moisture control. Finally, synthesising biochar-based materials for energy storage applications requires additional functionalisation.
The increasing global energy demand alongside the depletion of finite fossil-based fuels are driving our need for finding an alternative renewable source of energy on our way to the zero-carbon economy. Therefore, biomass is considered one of the most promising renewable feedstocks for energy generation or as a starting material in producing value-added products in the chemical industry. Herein, this chapter focuses on the utilization of biomass as a direct solid fuel or in the production of bio-oil through pyrolysis. The most up-to-date literature in this area is critically discussed and analyzed in this work to provide future directions throughout the various challenges and opportunities in this exciting area. The main focus of this chapter is to summarize the most recent advancements of biochar and bio-oil production for energy applications through bibliometric mapping analysis and put forward guidelines for the future routes herein. This chapter suggests that the approach of solid fuel production from biomass is a mature enough research area and technology for scale-up than that of bio-oil production from biomass. Significant present and future efforts should focus on the efficient production of bio-oil from biomass, especially in ways of improving the pretreatment methods and bio-oil upgrading phases to make it a more favorable utilization option.
Herein we demonstrate the preparation and characterization of nanocrystalline ZnO, either pure or promoted with 1–10 wt.% K2O. All catalysts calcined at 400°C were in the nano-crystallite scale as confirmed by X-ray powder diffraction analysis in the 22.9–28.0 nm range. According to the CO2-temperature-programmed desorption study using thermogravimetric analysis and differential scanning calorimetry techniques, they have a broad spectrum of surface basic sites. Because of the significance of methyl ethyl ketone (MEK) as a next-generation biofuel candidate with high-octane, low boiling point, and relatively high vapor pressure. The prepared catalysts were examined during the direct production of MEK via 2-butanol (2B) dehydrogenation. Among catalysts tested, ZnO promoted with 1% K2O showed a superior catalytic activity towards the conversion of 2B to MEK, that is, 71.7% at a reaction temperature of 275°C. The selectivity for the production of MEK over all catalysts was ≥95% across all catalysts when using N2-gas as a carrier. The use of airflow in this reaction resulted in a clear loss of selectivity toward MEK production as well as the appearance of undesirable products such as acetone and methanol. All catalytic properties of catalysts, particularly those of moderate strength, were highly correlated with the distribution of surface basic sites. Finally, a reaction mechanism was proposed for the dehydrogenation of 2B, followed by the partial oxidation of MEK. © 2022 The Authors. Energy Science & Engineering published by the Society of Chemical Industry and John Wiley & Sons Ltd.
This call is aimed at curating an edition of the journal focusing on a topical dimension to university law clinics, brought into sharp focus during the pandemic and its effects across the legal and business sectors. Undoubtedly there have been many direct and indirect effects caused by the pandemic on businesses and their operations in which law clinics have intervened, with others that have highlighted existing works. As noted across media sources, employee burnout, responsibilities surrounding health & safety, parental responsibilities during lockdowns, home working, the furlough scheme, changes to workers’ contracts, insolvency of businesses and redundancies, dismissals, leasing and business rates and supply chain management have each been a developing risk of the covid outbreak. Each of these matters, among the myriad others affecting all business types, have affected the international community, posing challenges for management, governance and legal regimes around the world. Instructions Please send abstracts of no more than 250 words by email to editors Lyndsey Bengtsson (lyndsey2.Bengtsson@northumbria.ac.uk) and/or James Marson (firstname.lastname@example.org) by 1st May 2022. Successful applicants will be informed in June 2022 with final drafts to be submitted by 31st October 2022. All submissions should follow the Author Guidelines. Authors need to register with the journal prior to submitting or, if already registered, can simply log in and begin the five-step process. All manuscripts will be subject to a double-blind peer-review process. The International Journal of Clinical Legal Education is an open access journal and does not apply an article processing charge for publication. Submitted papers should be formatted and presented in English. For more information please contact James Marson (email@example.com).
The increasing global industrialization and over-exploitation of fossil fuels has induced the release of greenhouse gases, leading to an increase in global temperature and causing environmental issues. There is therefore an urgent necessity to reach net-zero carbon emissions. Only 4.5% of countries have achieved carbon neutrality, and most countries are still planning to do so by 2050–2070. Moreover, synergies between different countries have hampered synergies between adaptation and mitigation policies, as well as their co-benefits. Here, we present a strategy to reach a carbon neutral economy by examining the outcome goals of the 26th summit of the United Nations Climate Change Conference of the Parties (COP 26). Methods have been designed for mapping carbon emissions, such as input–output models, spatial systems, geographic information system maps, light detection and ranging techniques, and logarithmic mean divisia. We present decarbonization technologies and initiatives, and negative emissions technologies, and we discuss carbon trading and carbon tax. We propose plans for carbon neutrality such as shifting away from fossil fuels toward renewable energy, and the development of low-carbon technologies, low-carbon agriculture, changing dietary habits and increasing the value of food and agricultural waste. Developing resilient buildings and cities, introducing decentralized energy systems, and the electrification of the transportation sector is also necessary. We also review the life cycle analysis of carbon neutral systems.
Measuring the Lewis‐acidic surface sites in catalysis is problematic when the material‘s surface area is very low (SBET ≤1 m2 ⋅ g−1). For the first time, a quantitative assessment of total acidic surface sites of very small surface area catalysts (MoO3 as pure and mixed with 5–30 % CdO (wt/wt), as well as CdO for comparison) was performed using a smart new probe molecule, tetrahydrofuran (THF). The results were nearly identical compared to using another commonly used probe molecule, pyridine. This audition is based on the limited values of the surface area of these samples that likely require a relatively moderate basic molecule as THF with pKb=16.08, rather than strong basic molecules such as NH3 (pKb=4.75) or pyridine (pKb=8.77). We propose mechanisms for the interaction of vapour phase molecules of THF with the Lewis‐cationic Mo and Cd atoms of these catalysts. Besides, dehydration of isopropyl alcohol was used as a probe reaction to investigate the catalytic activity of these catalysts to further support our findings in the case of THF in a temperature range of 175–300 °C. A good agreement between the obtained data of sample MoO3‐10 % CdO, which is characterised by the highest surface area value, the population of Lewis‐acidic sites and % selectivity of propylene at all the applied reaction temperatures was found. Measuring Lewis‐acidic surface sites in catalysis is problematic when the material‘s surface area is very low (SBET ≤1 m2 ⋅ g−1). For the first time, a quantitative assessment of total acidic surface sites of small surface area catalysts was performed using a new probe molecule, tetrahydrofuran. The results were nearly identical when compared to other commonly used probe molecule, pyridine. This work may be considered ground‐breaking in this field by applying the temperature‐programmed desorption (TPD) technique using both thermogravimetric (TG) and differential scanning calorimetry (DSC) analyses.
Herein, the aim was to develop an in-depth understanding of the kinetic behaviour of olive tree pruning residue (OTPR), an abundant agricultural waste, during pyrolysis. Thermal analysis at 1, 2, 4, 6 and 10 °C.min⁻¹ was performed using TGA-thermogravimetric analysis, with the results subsequently used to determine the OTPR's kinetic thermal breakdown behaviour. Furthermore, advanced kinetics and technology solutions (AKTS) thermo-kinetic tool was applied to investigate the kinetic behaviour of OTPR and to generate kinetic predictions for various heating configurations. Friedman's method was the main approach used to evaluate the kinetic parameters. For comparison, other established kinetic modelling techniques, such as ASTM-E698 and Flynn-Wall-Ozawa (FWO) methods, were applied. The former approach yielded an apparent activation energy (Ea) of 172.09 kJ.mol⁻¹, whereas the FWO method yielded an Ea range from 38 to 172 kJ.mol⁻¹. Finally, the differential iso-conversional approach yielded Ea values ranging between 85 and 191 kJ.mol⁻¹. Kinetic predictions were then developed for isothermal, non-isothermal, and stepwise configurations using the kinetic parameters obtained via Friedman’s model. The forecasts shed light on optimising production throughput in a variety of reactor configurations.
Integrated carbon capture and utilization (ICCU) presents an ideal solution to address anthropogenic carbon dioxide (CO2) emissions from industry and energy sectors, facilitating CO2 capture and subsequent utilization through conversion into high-value chemicals, as opposed to current release into the atmosphere. Herein, we report the synergistic coupling of porous CaO, as a sorbent for CO2 capture, and Ni doped CeO2 nanorods, as catalytic sites for CO2 reduction. It is found that ceria is shown to possess the capacity for CO2 utilization, however, critically it only results in the generation of CO due to the weak CO-ceria bonding. The addition of Ni active sites gives rise to CH4 being the predominant product, via the strong interaction between Ni species and CO, which facilitates further reduction. Through tuning Ni loading, we have evaluated the role of catalytic active site size, with a Ni loading of only 0.5wt.% providing optimal performance through the formation of sub-nanometer sized clusters. This near-atomic active site dispersion gives rise to CH4 productivity and selectivity of 1540 mmol g⁻¹ Ni and 85.8%, respectively, with this optimal combination of catalyst and sorbent demonstrating high stability over 10 cycles of ICCU process. These observations in parallel with the synergistic coupling of earth-abundant, low-cost materials (CaO and Ni) will have broad implications on the design and implementation of high efficiency, cost-effective ICCU materials and processes.
Conventional methods to clean wastewater actually lead to incomplete treatments, calling for advanced technologies to degrade recalcitrant pollutants. Herein we review solar photo-oxidation to degrade the recalcitrant contaminants in industrial wastewater, with focus on photocatalysts, reactor design and the photo-Fenton process. We discuss limitations due to low visible-light absorption, catalyst collection and reusability, and production of toxic by-products. Photodegradation of refractory organics by solar light is controlled by pH, photocatalyst composition and bandgap, pollutant properties and concentration, irradiation type and intensity, catalyst loading, and the water matrix.
Herein, we designed a cost-effective preparation method of nanocomposite γ-Al2O3 derived from Al-waste. The produced material has a feather-like morphology, and its adsorption of some chlorinated volatile organic compounds (Cl-VOC's) such as benzyl chloride, chloroform and carbon tetrachloride (C7H7Cl, CHCl3 and CCl4) was investigated due to their potential carcinogenic effect on humans. It showed a characteristic efficiency towards the adsorptive removal of these compounds over a long period, i.e., eight continuous weeks, at ambient temperature and atmospheric pressure. After 8-weeks, the adsorbed amounts of these compounds were determined as: 325.3 mg C7H7Cl, 247.6 mg CHCl3 and 253.3 mg CCl4 per g of γ-Al2O3, respectively. CCl4 was also found to be dissociatively adsorbed on the surface of γ-Al2O3, whereas CHCl3 and C7H7Cl were found to be associatively adsorbed. The prepared γ-Al2O3 has a relatively high surface area (i.e., 192.2 m². g⁻¹) and mesoporosity with different pore diameters in the range of 25–47 Å. Furthermore, environmental impacts of the nanocomposite γ-Al2O3 preparation were evaluated using life cycle assessment.
Hydrogen production through methane dry reforming holds the promise of lowering greenhouse gases, that is CO2 and CH4, concentrations. Herein, Ca-, Cr-, Ga- and Gd-promoted lanthana-zirconia–supported Ni catalysts are investigated and characterized by X-ray diffraction, Raman, infrared and UV-vis spectroscopy, CH4-temperature programmed surface reaction and cyclic reduction-desorption experiment. All promoted catalyst systems had high and constant hydrogen yield (>70%) due to pronounced reoxidation capacity of reduced ‘NiO species strongly interacted with support’ through oxygen replenishment by CO2. The presence of mixed oxide and regeneration of reduced catalyst up to optimum level through oxygen replenishment by CO2 in Gd, as well as Cr-promoted catalyst, outperformed (80% initially) than other promotors, Ca and Ga. In the long run (440 min to 33 h), Cr-promoted catalyst system performed better than Gd-promoted catalyst system as H2 yield remained constant ~79% due to the smallest energy gap between valance and conduction band, Ni-Cr interaction species for wide range CH4 decomposition and chromate species for profound carbon deposit oxidation.
The increasing significance of biomass in attaining ultimate sustainability in a multitude of vectors demands a deeper understanding of its underlying components. The pyrolytic breakdown of cellulose, a major biomass component, has been a subject of intense research since the 1950s, and despite significant research carried out and published thus far, the kinetics of cellulose degradation remains a source of debate. Herein, this work investigates the pyrolytic degradation of cellulose using Advanced Kinetics and Technology Solutions (AKTS) software. Kinetic parameters were computed using three methods, Friedman’s differential iso-conversional, FWO and ASTM-E698. The results indicate Ea values of 40-181, 68-166, and 152.1 kJ/mol, using Friedman’s, FWO and ASTM-E698 methods, respectively. Based on the results obtained via Friedman’s differential iso-conversional method, predictions under isothermal, non-isothermal and stepwise heating profiles are presented. The predictions revealed that rapid degradation takes place up to 80% conversion, and a temperature of 350-400°C is required to efficiently achieve this, while temperatures of 650°C and higher are needed to efficiently achieve a 100% conversion in less than 2 hours.
Prunus Armeniaca seed (PAS) oil was utilised as a waste biomass feedstock for biodiesel production via a novel catalytic system (SrO–La2O3) based on different stoichiometric ratios. The catalysts have been characterised and followed by a parametric analysis to optimise catalyst results. The catalyst with a stoichiometric ratio of Sr: La-8 (Sr–La–C) using parametric analysis showed an optimum yield of methyl esters is 97.28% at 65 °C, reaction time 75 min, catalyst loading 3 wt% and methanol to oil molar ratio of 9. The optimum catalyst was tested using various oil feedstocks such as waste cooking oil, sunflower oil, PAS oil, date seed oil and animal fat. The life cycle assessment was performed to evaluate the environmental impacts of biodiesel production utilising waste PAS, considering 1000 kg of biodiesel produced as 1 functional unit. The recorded results showed the cumulative abiotic depletion of fossil resources over the entire biodiesel production process as 22,920 MJ, global warming potential as 1150 kg CO2 equivalent, acidification potential as 4.89 kg SO2 equivalent and eutrophication potential as 0.2 kg PO4³⁻ equivalent for 1 tonne (1000 kg) of biodiesel produced. Furthermore, the energy ratio (measured as output energy divided by input energy) for the entire production process was 1.97. These results demonstrated that biodiesel obtained from the valorisation of waste PAS provides a suitable alternative to fossil fuels.
The rapid urbanization and industrialization is causing worldwide water pollution, calling for advanced cleaning methods. For instance, pollutant adsorption on magnetic oxides is efficient and very practical due to the easy separation from solutions by an magnetic field. Here we review the synthesis and performance of magnetic oxides such as iron oxides, spinel ferrites, and perovskite oxides for water remediation. We present structural, optical, and magnetic properties. Magnetic oxides are also promising photocatalysts for the degradation of organic pollutants. Antimicrobial activities and adsorption of heavy metals and radionucleides are also discussed.
Dihydrogen (H 2 ), commonly named ‘hydrogen’, is increasingly recognised as a clean and reliable energy vector for decarbonisation and defossilisation by various sectors. The global hydrogen demand is projected to increase from 70 million tonnes in 2019 to 120 million tonnes by 2024. Hydrogen development should also meet the seventh goal of ‘affordable and clean energy’ of the United Nations. Here we review hydrogen production and life cycle analysis, hydrogen geological storage and hydrogen utilisation. Hydrogen is produced by water electrolysis, steam methane reforming, methane pyrolysis and coal gasification. We compare the environmental impact of hydrogen production routes by life cycle analysis. Hydrogen is used in power systems, transportation, hydrocarbon and ammonia production, and metallugical industries. Overall, combining electrolysis-generated hydrogen with hydrogen storage in underground porous media such as geological reservoirs and salt caverns is well suited for shifting excess off-peak energy to meet dispatchable on-peak demand.
Rising demand for energy resources alongside climate emergency concerns has attracted the urgent attention of researchers towards the preparation and utilization of biofuels. This review will investigate the different generations of biofuels and more particularly, the developmental and production processes for creating liquid biofuels. Initially, the first-generation biofuel was dependent on edible resources, which has caused controversy and arguments on whether to fulfil the "food or fuel requirement" for civilization. Second-generation biofuels employed inedible resources, however, the cost of production at a commercial scale has restricted its expansion. Recently, third and fourth-generation use microorganisms and genetically modified microorganisms, respectively , to produce biofuels and create an efficient synthetic fuel switch route. Although the last two generations are still in the developmental phase, thorough research is required before commercial-scale production. In conclusion, this review has found that first-and second-generation biofuel production approaches will soon be inadequate to satisfy the exponentially rising demand for biofuels. Therefore, substantial research efforts currently and in the future should focus on the production of third and fourth-generation biofuels, especially on engineered microorganisms. Ultimately, the structure of this review is to outline the current state of the art research regarding biofuels, their production processes and limitations/challenges. This was done through critically reviewing the most up-to-date literature and utilizing bibliometric analysis tools to put forward the guidelines for the future routes of the four generations of biofuels.
As the global cumulative installation of solar photovoltaic (PV) devices grows every year, a proportionate number of waste PV modules arises because of their limited lifespan. It is estimated that by 2050, there will be approximately 60–78 million tonnes of PV waste (Farrell, C.; Osman, A. I.; Zhang, X. et al. Sci Rep.2019, 9, 5267). These modules are bound in a strong encapsulated laminate that is prone to imminent degradation. Subsequently, a form of treatment is required to remove a problematic polymeric material such as the encapsulant poly(ethylene-co-vinyl acetate) (EVA) in order to recycle. Pyrolysis is an ideal option that facilitates clean delamination by removing the polymer fraction, and it does not promote chemical oxidation to any of the constituents left behind after pyrolysis. To date, there are limited studies on the pyrolysis of EVA found in PV modules, resulting in significant gaps in the knowledge of pyrolysis kinetic parameters. This work aims to investigate the pyrolysis reaction kinetics concerning the EVA encapsulant found in end-of-life (EoL) crystalline silicon (c-Si) PV modules. The thermoanalytical technique employed was thermogravimetric analysis, which was carried out at 0.5, 1, 2, 4, and 5 °C min–1 to ensure accuracy and high resolution while analyzing the kinetics. The kinetic triplet was determined and reported for the first time using the Advanced Kinetics and Technology Solutions (AKTS) Thermokinetics software. The main kinetic modeling method employed was the Friedman differential isoconversional method. Other conventional kinetic modeling approaches were also used, such as the integral (Ozawa) and ASTM-E698 methods for comparison of apparent activation energy. It was observed that the activation energy values for each method were 167.66–260.00, 259.70, and 167.00–252.65 kJ mol–1 for EVA pyrolysis. Additionally, isothermal, nonisothermal, and step-based predictions were reported for the first time using the thermokinetics package. Furthermore, pyrolysis of EVA can have a triple role in the successful delamination of PV modules, recovery of additional constituents, and aiding of waste management of this problematic polymer.
In the context of climate change, there is an urgent need for rapid and efficient methods to capture and sequester carbon from the atmosphere. For instance, production, use and storage of biochar are highly carbon negative, resulting in an estimated sequestration of 0.3–2 Gt CO 2 year ⁻¹ by 2050. Yet, biochar production requires more knowledge on feedstocks, thermochemical conversion and end applications. Herein, we review the design and development of biochar systems, and we investigate the carbon removal industry. Carbon removal efforts are currently promoted via the voluntary market. The major commercialized technologies for offering atmospheric carbon removal are forestation, direct air carbon capture utilization and storage, soil carbon sequestration, wooden building elements and biochar, with corresponding fees ranging from 10 to 895 GBP (British pounds) per ton CO 2 . Biochar fees range from 52 to 131 GBP per ton CO 2 , which indicates that biochar production is a realistic strategy that can be deployed at large scale. Carbon removal services via biochar are currently offered through robust marketplaces that require extensive certification, verification and monitoring, which adds an element of credibility and authenticity. Biochar eligibility is highly dependent on the type of feedstock utilized and processing conditions employed. Process optimization is imperative to produce an end product that meets application-specific requirements, environmental regulations and achieve ultimate stability for carbon sequestration purposes.
Herein waste biomass (blackberry pomace) was physicochemically characterized along with its thermochemical products. This is coupled with the evaluation of the kinetic triplet (activation energy, pre-exponential constant, and the rate of reaction) and thermal predictions for the combustion process for the first time via the AKTS thermokinetics package. The main kinetic modeling method employed was the differential isoconversional analysis; however, the Flynn-Wall-Ozawa and ASTM E-698 methods were used as comparisons. The model was developed and validated from experimental DSC and TGA data, resulting in an excellent match (R2 = 0.99544 and 0.99194, respectively). The activation energies were evaluated using the ASTM-E698 method (88.64 kJ mol-1) and Flynn-Wall-Ozawa methods (50-140 kJ mol-1). The differential isoconversional method showed that activation energy values were in the range of 84-197 kJ mol-1 for the combustion of berry pomace. Isothermal predictions based on the model were indicated at temperatures of 560 and 600 °C; the reaction had achieved 100% completion (α = 1) after 30 and 6 min, respectively. For the nonisothermal prediction, the heating rates of 50, 75, and 100 °C/min have a two-stage rate profile with a maximum peak in the first stage of the reaction. Thereafter, the reaction rate increases once again but not to the same effect as the first initial stage. For instance, at 100 °C/min, stages 1 and 2 are reported as 0.005381 and 0.005148 s-1,respectively. Overall, this study demonstrates the success of the approach in modeling the thermochemical conversion of berry pomace as waste stream biomass.
Background: Recycling the ever-increasing plastic waste has become an urgent global concern. One of the most convenient methods for plastic recycling is pyrolysis, owing to its environmentally friendly nature and its intrinsic properties. Understanding the pyrolysis process and the degradation mechanism is crucial for scale-up and reactor design. Therefore, we studied kinetic modelling of the pyrolysis process for one of the most common plastics, polyeth-ylene terephthalate (PET). The focus was to better understand and predict PET pyrolysis when transitioning to a low carbon economy and adhering to environmental and governmental legislation. This work aims at presenting for the first time, the kinetic triplet (activation energy, pre-exponential constant, and reaction rate) for PET pyrolysis using the differential iso-conversional method. This is coupled with the in-situ online tracking of the gaseous emissions using mass spectrometry. Results: The differential iso-conversional method showed activation energy (E a) values of 165-195 kJ mol −1 , R 2 = 0.99659. While the ASTM-E698 method showed 165.6 kJ mol −1 and integral methods such as Flynn-Wall and Ozawa (FWO) (166-180 kJ mol −1). The in-situ Mass Spectrometry results showed the gaseous pyrolysis emissions, which are C 1 hydrocarbons and H-O-C=O along with C 2 hydrocarbons, C 5-C 6 hydrocarbons, acetaldehyde, the fragment of O-CH=CH 2 , hydrogen, and water. Conclusions: From the obtained results herein, thermal predictions (isothermal, non-isothermal and step-based heating) were determined based on the kinetic parameters. They can be used at numerous scale with a high level of accuracy compared with the literature.
Supercapacitors are increasingly used for energy conversion and storage systems in sustainable nanotechnologies. Graphite is a conventional electrode utilized in Li-ion-based batteries, yet its specific capacitance of 372 mA h g−1 is not adequate for supercapacitor applications. Interest in supercapacitors is due to their high-energy capacity, storage for a shorter period and longer lifetime. This review compares the following materials used to fabricate supercapacitors: spinel ferrites, e.g., MFe2O4, MMoO4 and MCo2O4 where M denotes a transition metal ion; perovskite oxides; transition metals sulfides; carbon materials; and conducting polymers. The application window of perovskite can be controlled by cations in sublattice sites. Cations increase the specific capacitance because cations possess large orbital valence electrons which grow the oxygen vacancies. Electrodes made of transition metal sulfides, e.g., ZnCo2S4, display a high specific capacitance of 1269 F g−1, which is four times higher than those of transition metals oxides, e.g., Zn–Co ferrite, of 296 F g−1. This is explained by the low charge-transfer resistance and the high ion diffusion rate of transition metals sulfides. Composites made of magnetic oxides or transition metal sulfides with conducting polymers or carbon materials have the highest capacitance activity and cyclic stability. This is attributed to oxygen and sulfur active sites which foster electrolyte penetration during cycling, and, in turn, create new active sites.
The ever-increasing world energy demand drives the need for new and sustainable renewable fuel to mitigate problems associated with greenhouse gas emissions such as climate change. This helps in the development toward decarbonisation. Thus, in recent years, hydrogen has been seen as a promising candidate in global renewable energy agendas, where the production of biohydrogen gains more attention compared with fossil-based hydrogen. In this review, biohydrogen production using organic waste materials through fermentation, biophotolysis, microbial electrolysis cell and gasification are discussed and analysed from a technological perspective. The main focus herein is to summarise and criticise through bibliometric analysis and put forward the guidelines for the potential future routes of biohydrogen production from biomass and especially organic waste materials. This research review claims that substantial efforts currently and, in the future, should focus on biohydrogen production from integrated technology of processes of (i) dark and photofermentation, (ii) microbial electrolysis cell (MEC) and (iii) gasification of combined different biowastes. Furthermore, bibliometric mapping shows that hydrogen production from biomethanol and the modelling process are growing areas in the biohydrogen research that lead to zero-carbon energy soon. Graphical Abstract
Climate change is defined as the shift in climate patterns mainly caused by greenhouse gas emissions from natural systems and human activities. So far, anthropogenic activities have caused about 1.0 °C of global warming above the pre-industrial level and this is likely to reach 1.5 °C between 2030 and 2052 if the current emission rates persist. In 2018, the world encountered 315 cases of natural disasters which are mainly related to the climate. Approximately 68.5 million people were affected, and economic losses amounted to $131.7 billion, of which storms, floods, wildfires and droughts accounted for approximately 93%. Economic losses attributed to wildfires in 2018 alone are almost equal to the collective losses from wildfires incurred over the past decade, which is quite alarming. Furthermore, food, water, health, ecosystem, human habitat and infrastructure have been identified as the most vulnerable sectors under climate attack. In 2015, the Paris agreement was introduced with the main objective of limiting global temperature increase to 2 °C by 2100 and pursuing efforts to limit the increase to 1.5 °C. This article reviews the main strategies for climate change abatement, namely conventional mitigation, negative emissions and radiative forcing geoengineering. Conventional mitigation technologies focus on reducing fossil-based CO2 emissions. Negative emissions technologies are aiming to capture and sequester atmospheric carbon to reduce carbon dioxide levels. Finally, geoengineering techniques of radiative forcing alter the earth’s radiative energy budget to stabilize or reduce global temperatures. It is evident that conventional mitigation efforts alone are not sufficient to meet the targets stipulated by the Paris agreement; therefore, the utilization of alternative routes appears inevitable. While various technologies presented may still be at an early stage of development, biogenic-based sequestration techniques are to a certain extent mature and can be deployed immediately.
A certificate recognized by accreditation training issued to Dr. KIES Fatima for participating in the webinar "New Organization and Digitization of the Company: The Role of Continuous Training". Released by "Life Learning Italy" on July 16th, 2020.
The global exponential increase in annual photovoltaic (PV) installations and the resultant levels of PV waste is an increasing concern. It is estimated by 2050 there will be between 60 and 78 million tonnes of PV waste in circulation. This review will investigate and establish the most efficient routes to recycle end-of-life modules. It will consider current design constraints, focusing on the maximum recovery of constituents from the module, reporting on some of the latest advancements in recycling methodology at both industrial and laboratory scale. Circular challenges, opportunities, models and arguments are presented for critical analysis of closed-loop recycling alongside alternative open-loop cascading options. Adopting circular economy principles will help offset environmental factors such as emissions associated with the manufacturing stages and increase recycling & recovery rates. First-generation crystalline silicon (c-Si) modules have had an 80–90% market share over the last 40 years and will constitute the majority of the impending PV waste stream. These PV modules are composed of several material types such as glass, metal, semiconductor and polymer layers in a strongly bound laminate. This design makes reusing and maintaining these modules difficult and limits potential recycling options. Here we provide guidance for understanding the c-Si PV module manufacturing process and how to best approach the challenge of recycling this vast and inevitable waste stream. In conclusion, pyrolysis offers the best potential for the optimum recovery of material and energy found in first-generation c-Si modules to help promote a truly circular economy within the well-established PV industry.
The Mediterranean environment stressors and their effect on the trophic state require the assessment of interconnection between land-based drivers, the real and potential pressures and impacts. To achieve this, it is necessary to consider as well, several social and economic factors that may influence decision-making around land-sea planning and the management of nutrients, pollutants, and sediment transport. Moreover, once the ecological situation is characterized, it is advisable to establish the linking between the natural systems and the ecosystem services. In the Mediterranean Sea, it fairly demonstrated by ecosystem-based management approaches and the literature that human activities can affect the water column, seafloor, and biodiversity, among others. Moreover, it is a fact that these issues require a detailed piece of knowledge of a wide variety of geological, sociological, economical and biological variables, among others. Those variables are dependent on prioritizes actions. One of them is the monitoring, mitigation, and control of the eutrophication processes, which needs the deconstruction of the Integrated Coastal Zones Management (ICZM) approach into priorities actions, in accordance with the multi-level water characteristics and their interconnection, i.e., the coastal zone dynamics, and the multilevel governance.