No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The use of exhausted grape marc to produce biofuels and biofertilizers: Effect of pyrolysis temperatures on biochars properties
Abstract
The wine industry represents an important economic sector in the Mediterranean countries. Currently, grape marc is valorized for ethanol production by distillation process generating a second residue called exhausted grape marc (EGM) that should be properly managed in order to avoid any related negative impacts onto the environment. In the present investigation, an innovative strategy was proposed to convert EGM into biofuels and biofertilizers through thermochemical conversion process such as carbonization/pyrolysis technique. In order to select the appropriate operating parameters, the impact of the slow pyrolysis temperatures of EGM (from 300 to 700 °C) on biochar production yields as well as their physico-chemical characteristics were assessed. The experimental results showed that the biochars yields production decrease with increasing the pyrolysis temperature and reach a plateau above 500 °C. The biochar yield at 500 °C is around 33%, which is amongst the highest values obtained for food processing residues. The biochar physico-chemical characterization showed a higher surface area (253.4 m²/g) was obtained for the char prepared at 600 °C. However, the maximum nutrients contents, namely potassium, nitrogen and phosphorus were registered at 500 °C. Based on the biochar yields and characteristics, it seems that EGM biochar produced through slow pyrolysis at 500 °C could be considered as a promising biofertilizer for agricultural purposes.
... The researches implied that among these, the supercapacitors having higher power density, cyclic stability and comparison of more energy density to the conventional capacitors [4,7]. In addition to these characteristics, supercapacitors also have wide temperature range operations, excellent in electric conductivity and other advantages [8]. Based on the working model of supercapacitors, classified in to three groups. ...
... Due to the abundant available of biomass source, excessive development and fossil fuels consumption, these carbon products produced from biomass is a low-cost and sustainable method of conversion technology. Along with the biomass energy remaining green and sustainable energies were also gain more attention [7,8,20]. ...
In India, there is a plenty of biomass generating from the various sources like industry, agriculture etc. The
thermochemical conversion output products are becoming more familiar in the field of energy storage like fuel
cells, supercapacitors and batteries. Because of their high-power density and extended life cycle, supercapacitors
are playing an increasingly significant role in the energy storage sector. Supercapacitors have seen many advances
in recent years. The most popular electrode material for supercapacitors is carbon, and studying carbon is
important for creating new kinds of supercapacitors. This article describes the materials usually utilized for
carbon electrodes and the energy storage techniques of supercapacitors. The most widely used carbon materials
and their uses in the field of supercapacitors are introduced in the section on carbon electrode materials. Ultimately,
the trajectory of advancement for carbon-based supercapacitors is anticipated. Supercapacitors have
made a lot of advancements lately. This paper describes the carbon production technologies, electrode preparation
for the energy storage supercapacitor, electrolytes and various separators were discussed.
... Grape pomace is an important source of polyphenols and essential oils, which are antioxidant, antimicrobial, anti-inflammatory, and anticarcinogenic, and can be used as food additives or pharmaceuticals. 7 In addition to these products, chemical, physical, and biological processes can be used to produce fertilizers, 8 biochar, 9 tannins, 10 and biofuels such as biodiesel 11 and bioethanol. 12 The composting of grape pomace allows this residue to be used to improve soil properties or as animal feed. ...
... The procedure for estimating the energy balance is the same as for the combustion and gasification processes. The pyrolysis temperature is set at 500°C since the biochar obtained with these operating conditions presents the maximum nutrient contents (nitrogen, phosphorus and potassium) following the results of Ferjani et al. 9 This process is modeled using the empirical yield to estimate the amount of gas (38% of the dry pomace), bio-oil (31% of the dry pomace) and biochar (30% of the dry pomace), as well as, their compositions. 34 The energy requirement is also estimated using empirical yields. ...
The increase in the world population has led to intensive food production systems that are generating increasing amounts of solid waste. In this work, the valorization of the most important waste generated during wine production, grape pomace, is evaluated. Eight processes are proposed to approach different types of valorization (production of energy and value-added products), from economic, environmental, and social points of view. The best process depends on the budget available, the production capacity, and the weight of each impact produced by the factory (economic, environmental, or social). For small (less than 0.1 kg/s) or very large (greater than 10 kg/s) capacities, the production of high-value-added products outperforms the other processes in all three impacts and in profitability. For intermediate capacities, combustion and gasification stand out as having the highest greenhouse emissions and intermediate economic benefits. Anaerobic digestion is remarkable for its low greenhouse gas emissions, while tannin production is the best-balanced process from both economic and environmental points of view. Pyrolysis is the worst process of all three impacts.
... Therefore, at the end of vinification and distillery process, a vast amount of several by-products is obtained, which must be treated somehow to alleviate the negative impact of their formation to the environment. Among these, grape stalks (GS), grape marc (GM) or exhausted grape marc (EGM) should be noted, as they are potential lignocellulosic feedstocks with a clear valorization towards multiple end-value-added chemicals [7,8]. For instance, GS and GM are two widely studied matrices, as well-known. ...
... These excellent energetic properties for EGM agree with the literature as well, where some authors already reported the exploitation of this matrix to produce biofuels and bio-chars, being the latter further useful as Table 1 Characterization of the winemaking wastes grape stalks (GS), grape marc (GM) and exhausted grape marc (EGM). bio-fertilizers [8,42]. Moreover, it embraces a valuable achievement in terms of sustainability, especially because of the lower harmful emissions generated after biomass combustion step. ...
This work aims to establish a novel zero-waste-based assessment for the winemaking-derived by-products grape stalks (GS), grape marc (GM), and exhausted grape marc (EGM). To this end, the application of sustainable, intensified technologies as pulsed electric fields (PEF) (3 kV/cm, 100 kJ/kg, 2 Hz, 100 ms) was firstly evaluated to recover biologically active compounds (BACs). In this regard, results from EGM should be mentioned, with an increased efficiency to up to 68 % above the conventional soaking. In addition, it was supposed the first PEF processing to this matrix, to the best of our knowledge. In parallel, with view to the desirable conditions of zero-waste, alternative valorization routes were proposed considering the in-depth characterization carried out. For instance, the exploitation of EGM towards bioenergy was firmly suggested according to its proximate and ultimate analyses, and higher heating value (HHV). Further, it was also noteworthy the amount of holocellulose and lignin present in all GS, GM, and EGM (28–35 % and 28–45 %, respectively), relevant to develop a wide range of fine chemicals as levulinic acid or furfural. Finally, the lipidic fraction, useful as food ingredient or for biodiesel production, was isolated and characterized by NMR, being remarkable the detected amount for GM (7 %).
a personalized URL providing 50 days' free access to the article:
https://authors.elsevier.com/a/1hPTs7tGO%7EO4A9
... As a result, BC has a higher capacity to adsorb moisture and nutrients into the soil [80,82]. The increasing temperature has the opposite effect on concentrations of acidic functional groups, volatile matter, BC yield and cation exchange capacity (CEC) [83,84]. The type of material from which the BC is produced (known as feedstock), has a tremendous effect on the content of fixed carbon, TOC (total organic carbon) and mineral elements within the BC [85]. ...
... In the same way, the aged-BC also limits underground root biomass of rice (Oryza sativa) and tomato (Solanum lycopersicum). In addition, BC can decrease soil thermal, coming from the low thermal diffusivity of BC [84]. On the other hand, popular findings show that the positive effects of BC are soil-specific. ...
Potential Role of Biochar on Capturing Soil Nutrients, Carbon Sequestration and Managing Environmental Challenges: A Review
... Therefore, at the end of vinification and distillery process, a vast amount of several by-products is obtained, which must be treated somehow to alleviate the negative impact of their formation to the environment. Among these, grape stalks (GS), grape marc (GM) or exhausted grape marc (EGM) should be noted, as they are potential lignocellulosic feedstocks with a clear valorization towards multiple end-value-added chemicals [7,8]. For instance, GS and GM are two widely studied matrices, as well-known. ...
... These excellent energetic properties for EGM agree with the literature as well, where some authors already reported the exploitation of this matrix to produce biofuels and bio-chars, being the latter further useful as Table 1 Characterization of the winemaking wastes grape stalks (GS), grape marc (GM) and exhausted grape marc (EGM). bio-fertilizers [8,42]. Moreover, it embraces a valuable achievement in terms of sustainability, especially because of the lower harmful emissions generated after biomass combustion step. ...
Valorization of agri-food residues to produce bio-based platform chemicals will enhance the transition to the bio-economy era. To this end, a sustainable process has been developed for the overall valorization of grape stalks (GS) according to a circular approach, starting from the lignin fraction to further deal with the cellulose-rich residue. This non-conventional protocol fully adheres to green chemistry principles, exploiting the so-called enabling technologies—mainly ultrasound and microwaves—for energy-saving innovative processes. Firstly, ultrasound-assisted extraction (UAE, 40 kHz, 200 W) demonstrated to be an excellent technique for GS delignification combined with natural deep eutectic solvents (NaDESs). Delignification enables isolation of the pertinent lignin framework and the potential to obtain a polyphenol-rich liquid fraction, focusing on the valorization of GS as source of bioactive compounds (BACs). Among the NaDESs employed, the combination of choline chloride (ChCl) and levulinic acid (LevA) (ChLevA) presented noteworthy results, enabling a delignification higher than 70%. LevA is one of the top-value biobased platform chemicals. In this work, a flash microwave (MW)-assisted process was subsequently applied to the cellulose-rich fraction remained after delignification, yielding 85% LevA. The regeneration of this starting compound to produce ChLevA can lead to a further biomass delignification cycle, thus developing a new cascade protocol for a full valorization of GS.
... Pyrolysis is a process by which organic materials suffer thermal degradation into smaller volatile particles, without oxygen or any other oxidants [11]. By-products are converted into oils, a mixture of gases (methane, hydrogen, carbon dioxide, and carbon monoxide), ash, mainly enriched with carbon, and heat energy [3,35,44]. Gurevich Messina et al. [45] applied copyrolysis on peanut shells and cassava starch mixtures obtaining biochar with low water and mineral content and maximizing the biooil yield. A mixture composed of 75 w % of starch and 25 w % of peanut shells led to a maximum bio-oil yield (58.2 w %), while its water content was reduced by 3.4% compared with the value expected from the weighted average of the individual results of each component in the mixture. ...
... Biofuel production can use substrates such as seeds, grains, or sugars from crops of maize, wheat, rice, and first-generation sugar. However, these conflict with food production; thus, alternative sources rich in lignocellulosic biomass such as by-products are sought [44]. The use of by-products does not enter conflict with staple foods, in addition to be low-cost substrates. ...
Over four billion tons of foods are produced annually on the planet, and about a third is wasted. A minimal part of this waste is incinerated or sent to landfills for treatment, avoiding contamination and diseases; the rest is disposed of elsewhere. The current review was aimed at broadening the panorama on the potential of agroindustrial by-products in applications such as biofuels, biomaterials, biocompounds, pharmaceuticals, and food ingredients. It also exposes the main chemical, physical, and biochemical treatments for converting by-products into raw materials with added value through low environmental impact processes. The value of agroindustrial waste is limited due to the scarce information available. There is a need for further research in unexplored areas to find ways of adding value to these by-products and minimizing their contamination. Instead of throwing away or burning by-products, they can be transformed into useful materials such as polymers, fuels, antioxidants, phenols, and lipids, which will effectively reduce food waste and environmental impact.
... At the same time, the excessive and irrational use of inorganic fertilizers may be responsible for land degradation [4], nutrients leaching from agricultural soils [5] and freshwater body eutrophication [6]. One of the promising strategies for achieving a better soil nutrient balance as well as reducing aquifer contamination is to use slow-release nutrient biofertilizers instead of synthetic industrial fertilizers [7,8] The kinetics of nutrient release decreases with time exponentially and can be well described using first-order, pseudo-second-order, diffusion and Elovich equations [8,16,22,23,26]. These equations were fitted to experimental data to estimate the leaching rates of nutrients from biochar and their availability. ...
... The lower 30 cm of the columns were filled with the reference soil (0% of biochar), whilst the upper 20 cm were filled with a biochar-soil mix in four different proportions, 0.5%, 1%, 2% and 10% of biochar ( Figure 1). The first three doses of biochar used were such that they could be applied in a realistic agronomic application [8,16], while the 10% dose was used for modeling and exploratory purposes. After filling the columns, they remained intact for 45 days to achieve homogenization between the soil and the biochar. ...
This work examines in silico the dominant geochemical processes that control inorganic nutrients (Ca, Mg, Na, K) availability in irrigated agricultural soil amended with potassium-enriched biochar (from olive mill wastes) at mass doses of 0.5%, 1%, 2% and 10%. The geochemical modelling step was supported by analytical measurements regarding the physicochemical characteristics of the irrigation water, the agricultural soil and the biochar. Two geochemical approaches, namely equilibrium exchange (E.E.) and kinetic exchange (K.E.) models were applied and compared to assess nutrient release with an emphasis on potassium availability. Equilibrium exchange perspective assumed that nutrient release is controlled by ion-exchange reactions onto the biochar surface , whilst kinetic exchange perspective assumed the contribution of both ion-exchange and dissolution of salts. Results indicated that for the E.E. model, the soluble amount of potassium is readily available for transport within the pores of the porous media, and therefore is leached from the column within only 10 days. For the K.E. model that assumes a kinetically controlled release of potassium due to interactions occurring at the solid-solution interface, the assessed retention times were more realistic and significantly higher (up to 100 days). Concerning the applied doses of biochar, for a 2% biochar fraction mixed with soil, for example, the available K for plants doubled compared with the available K in the soil without biochar. In any case, the use of numerical modeling was proven helpful for a quick assessment of biochar performance in soil, by avoiding time-consuming and laborious experimental setups. Validation of the models by experimental data will further establish the proposed mechanisms.
... Such an ap-proach will be helpful in directing research towards the most efficient, effective and profitable solutions. In the literature there is a limited number of studies (Ibn Ferjani et al., 2019;Oh et al., 2012;Pariyar et al., 2020;Stylianou et al., 2020;Taskin et al., 2019) referring to biochar characterization aiming at both agronomic and environmental uses. ...
... The decrease in H and O contents with increasing pyrolysis temperature is quite common in the literature and is usually attributed to breakage of weak bonds in the biochar structure (Al-Wabel et al., 2013;Rehrah et al., 2016). As far as the C content is concerned, the most commonly observed behavior is its increase as a function of temperature (Colantoni et al., 2016;Gómez et al., 2016;Ibn Ferjani et al., 2019;Tag et al., 2016) and it is usually an indication of an intensified carbonization (Rehrah et al., 2016). On the other hand, C loss has also been reported (Cao and Harris, 2010;Kah et al., 2016;Lu et al., 2013). ...
This study focused on the valorization of different types of waste biomass through biochar production at two pyrolysis temperatures (400 and 600°C). The different feedstocks being used included three materials of municipal origin, specifically two types of sewage sludge and the organic fraction of municipal solid waste, and three materials of agroindustrial origin, specifically grape pomace, rice husks and exhausted olive pomace. The scope of the research was to characterize the resulting materials, in order to evaluate their possible uses in agronomic and environmental applications. Biochar characterization included the determination of several physical and chemical parameters, while germination assays were also carried out. Under the investigated conditions, both pyrolysis temperature and feedstock type appeared to significantly affect biochar characteristics, leading to the production of versatile materials, with many different possible uses. Specifically, results implied that biochars of both municipal and agroindustrial origin have the potential to effectively be used in applications including the improvement of soil characteristics, carbon sequestration, the removal of organic and inorganic contaminants from aqueous media, and the remediation of contaminated soil, with the degree of suitability of each material to each specific use being estimated to differ depending on its particular characteristics. For this reason, with these characteristics in mind, before proceeding to larger scale applications a cautious selection of materials should be conducted.
... For instance, such form may be agricultural biomass fibre such as kenaf core fibre which was used to produce activated carbon by using an acidic chemical agent [2]. Besides that, fruit waste such as citrus peel waste and exhausted grape marc from the food processing industry is also used as biomass to produce either biofuels or biochar [4,5]. Concepts of using citrus peel waste that consist of orange peels, bagasse, and seeds which are mainly carbohydrates to produce biofuels are being researched [4]. ...
... Slow pyrolysis is pyrolysis with a slower heating rate and longer residence time for biomass, approximately 0.02 • C s -1 to 1 • C s -1 for heating rate, with a residence time ranging between few hours or even days. The temperature range for slow pyrolysis fall between 300 • C and 700 • C. For fast pyrolysis, the heating rate would be above 2 • C s -1 with a short residence time below 10 s, with a moderate temperature around 300-1000 • C [3,5]. Most of the methods are discovered based on slow pyrolysis as it has more disadvantages such as time-consuming and low energy efficiency, hence methods like vacuum pyrolysis and microwave pyrolysis are introduced based on slow pyrolysis to modify the weaknesses. ...
The current environmental pollution and global warming may cause a serious ecological crisis. The conversion of renewable resources, especially from biomass could be a promising option to alleviate this crisis. Traditionally, carbon produced from petrochemicals and coal are typically using large amount of energy and produce substantial quantities of pollutants. There is a need to develop alternative and effective methods to synthesize carbon from renewable resources with high performance and minimal environmental impact. Biochar is a rich carbon material derived from plant-based biomass. Biochar is one of the most ideal materials in various applications by considering it is low thermal conductivity, high porosity, high surface area, renewability, high stability, high carbon content and bulk density. In this regard, biochar has been widely recognized as the suitable candidate for sustainable carbon material. Thus, in this review, recent progresses towards the applications of biochar-based materials in various applications, such as wastewater treatment, soil amendments, catalyst or catalyst precursors and energy storage, are summarized and discussed. The various sources of biomass, synthesis techniques, and the effects of various factors involved in the carbonization process to generate different physicochemical properties biochar from the biomass is elaborated. Also, this review is highlighting the characteristics of the biochar and the carbonization mechanisms of different synthesis technologies. This review shows the great potential of different applications of biochar, which is expected to simulate new development to promote the use of biochar materials to achieve a sustainable environment and circular bio-economy.
... Extractives, the least abundant component, make up the remaining 0-14% [140][141][142]. The conversion efficiency of biomass to biofuels is influenced by various factors, including the feedstock's chemical composition, moisture content, reactor configuration, and operational temperature parameters [143][144][145][146]. The blending of biomass feedstock with complementary materials during pyrolysis may boost the output and worth of the subsequent outputs, as demonstrated in Table 5. [170] Various methods exist for the biomass pyrolysis, including thermo-chemical, biological, and chemical alteration. ...
The escalating demand for plastic presents an immense peril to both the environment and humanity. Not only have there been notable advancements in the creation of advanced biodegradable polymers, but there has also been a lack of attention towards tackling the current issue of plastic waste. Processing fuels via plastic waste valorization provides a feasible approach to recycle plastics and mitigating pollution for the improvement of society. This review addresses a comprehensive analysis of various heterogeneous catalysts in the context of plastic pyrolysis to produce fuel, intending to identify an eco-friendly method for recycling garbage. The choice of catalyst has a substantial effect on the disintegration process of waste plastic, dictating the properties of the resulting fuel, encompassing both the amount and the quality. Pyrolysis, an alternative method for addressing the increasing waste disposal issue, is a non-toxic process that does not release hazardous pollutants, in contrast to incineration. The waste plastic serves as a feedstock for pyrolysis process, employing innovative, environmentally friendly catalysts derived from natural and other sources, to generate fuel oil that possesses similar physical characteristics to the diminishing petroleum-based fuels. This critical review analyzes the impact of different heterogeneous catalysts on the process of transforming waste plastic to produce fuel through pyrolysis. Heterogeneous catalysts are crucial to the process of turning discarded plastics into oil, offering significant potential for improving not only economic and environmental conditions but also benefiting both industry and society.
... For these reasons, several studies have been recently carried out with the aim of reusing this residue as a source of energy and/or value-added products for obtaining economic and environmental benefits. For example, different chemical, physical and biological strategies have been applied to transform grape pomace into fertilizers [17], biofuels [18], biochar [19], and food additives and nutraceutical ingredients have been obtained by virtue of the antioxidant/antibacterial, and health-promoting activities of compounds still present in it, such as polyphenols, fibers, unsaturated fatty acids, and vitamins [20][21][22][23]. One of these valuable specialized metabolites in grape pomace is represented by anthocyanins, a class of water-soluble flavonoids possessing a wide array of biological properties. ...
Grape pomace is the main by-product obtained from wine production that is still enriched in bioactive compounds. Within a framework of waste/by-product reuse through a sustainable approach, various green methods were utilized in this work to recover anthocyanins from the pomace resulting from “Sangiovese” grape vinification. Ultrasound- and Microwave-Assisted Extractions (UAE and MAE) were coupled with the use of green solvents, such as acidified water, an ethanol/water mixture, and Natural Deep Eutectic Solvents (NaDES), and their efficacy was compared with that of a conventional method based on a methanol/acidified water mixture. The Total Anthocyanin Index ranged from 36.9 to 75.2 mg/g DW for UAE, and from 54.4 to 99.6 mg/g DW for MAE, while resulting in 47.1 mg/g DW for conventional extraction. A Design of Experiments (DoE) approach was applied to MAE, the most efficient technique. Temperature, time, and the solid-to-liquid ratio were set as X variables, while malvidin-3-O-glucoside content and antioxidant activity were used as response variables, measured by High-Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The correlation between temperature and time and the antioxidant activity of the extract was positive, while it was found to be negative when considering malvidin-3-O-glucoside concentration as a response variable. Thus, the optimal conditions in temperature, time and solid-to-liquid ratio were different depending on the chosen variable. The results underline the importance of selecting an accurate response when using the response surface methodology approach.
... They presented data on the efficiency of the activated carbons obtained in the experiment carried out in the temperature range of 300-700 °C. In light of the data presented, they reported that the activated carbon obtained at 300 °C temperature has lower carbon content and higher mineral content compared to the activated carbon obtained at 700 °C temperature (Ibn Ferjani et al. 2019). In this study, the FTIR analysis was used to make sense of the surface functional groups of the activated carbons obtained and to examine the difference in adsorption capacity. ...
In this study, activated carbons were obtained from grape marc for tetracycline removal from wastewater. Activated carbons were obtained by subjecting them to pyrolysis at 300, 500, and 700 °C, respectively, and the effect of pyrolysis temperature on activated carbons was investigated. The physicochemical and surface properties of the activated carbons were evaluated by SEM, FTIR, XRD, elemental analysis, N2 adsorption/desorption isothermal, thermal gravimetric (TG) and derivative thermogravimetric (DTG), and BET surface area analysis. When the BET surface areas were examined, it was found that 4.25 m²/g for activated carbon was produced at 300 °C, 44.23 m²/g for activated carbon obtained at 500 °C and 44.23 m²/g at 700 °C, which showed that the BET surface areas increased with increasing pyrolysis temperatures. The pore volumes of the synthesized activated carbons were 0.0037 cm³/g, 0.023 cm³/g, and 0.305 cm³/g for pyrolysis temperatures of 300, 500, and 700 °C, respectively, while the average pore size was found to be 8.02 nm, 9.45 nm, and 10.29 nm, respectively. A better adsorption capacity was observed due to the decrease in oxygen-rich functional groups with increasing pyrolysis temperature. It was observed that the activated carbon obtained from grape skins can easily treat hazardous wastewater containing tetracycline due to its high carbon content and surface functional groups. It was also shown that the activated carbon synthesized in this study has a higher pore volume despite its low surface area compared to the studies in the literature. Thanks to the high pore volume and surface active groups, a successful tetracycline removal was achieved.
Graphical Abstract
... Studies reveal several food waste substrates to produce hydro chars under specific environmental conditions. The common food wastes studied were sweet corn (Wakudkar & Jain, 2022), peanut shell (Mathabatha et al., 2022), brewer's spent grain (Bachmann et al., 2022), distiller's grain (Chen et al., 2022), grape pomace (Ferjani et al., 2019), and olive pomace (Zhu et al., 2022). The hydrochar contained 45% greater carbon content and 15-30 kJ/g of the dry solids. ...
Background
Food waste (FW) typically comprises waste from households, food industries, and food outlets. It is mainly composed of fruit and vegetable residues, grain residues, meat and poultry waste, dairy waste, and seafood waste. FW is responsible for one-tenth of greenhouse gas emissions from the entire food system. This serious issue needs to be resolved as per the 12th Sustainable Development Goal of the United Nations (UN-SDG) for a sustainable food system.
Scope and approach
Along with the current mitigation strategies, innovative technical interventions are required to achieve a zero-waste food system. FW is a rich source of several biomolecules, including protein, carbohydrates, oil, vitamins, bioactive compounds, and minerals. To extract such valuable biomolecules, upcycling FW is a need for the hour. A suitable pre-treatment method and FW bioconversion strategy are the key approaches for a circular bioeconomy. The upcycling of FW not only establishes a sustainable food system, but also provides several valuable products, such as biofuels, organic acids, biomaterials, bioactive compounds, biochar, bioenzymes, and biofabrics.
Key findings and conclusions
The value-added products possess wide applications in the health, food, chemical, cosmetic, textile, pharmaceutical, and nutraceutical industries. Life cycle assessment (LCA) is a crucial approach for assessing the environmental impact of a system, product, or process. It constitutes all sides of a system, including social, economic, and environmental to minimize the waste at every step of processing. Therefore, it is crucial to develop and adopt innovative technologies to valorize FW for achieving and maintaining a self-sustainable future.
... The biowaste can be converted into the high value-porous activated carbon with large speci c surface area that is commonly used for several kinds of applications such as adsorbent [16,17], catalyst [18,19], to energy storage systems [20][21][22][23]. Compared to commercial carbon materials, activated carbon-based biowaste can be synthesized by the facile process through hydrothermal [24,25], chemical activation [26-28], or pyrolysis carbonization [29][30][31]. Recently, activated carbon-based biowaste materials by facile preparation have been studied for microwave absorber application. ...
A well-developed porous activated carbon materials were synthesized from palm kernel shell (PKS) waste through the facile carbonization process with several KOH concentration, and the microwave absorbing performance were studied in the X-band range. The XRD and EDX measurement results confirmed the transformation from crystalline structure to the amorphous structure of cellulose of PKS materials with the higher carbon content. The BET analysis measures the pore size between 2–4 nm and a specific surface area between 554–825 m ² /g. All activated carbon materials show the improvement of microwave absorbing performance compared to its hydro char or raw PKS materials, with the highest minimum return loss and frequency bandwidth of -37.85 dB at 11.02 GHz and 900 MHz, respectively, for activated carbon with only KOH concentration of 10%. The porous structure of AC-based PKS is benefitted to give better impedance matching and dielectric loss capacity to enhance the microwave absorbing performance of AC-based PKS waste. This observation indicates that the activated carbon can be synthesized with a facile process from PKS waste and expands the possible utilization of AC-based PKS waste as the prospective microwave absorber materials for electronics and telecommunication devices.
... For example, Kumar Singh et al. [21] reported that pyrolysis of three types of tyre wastes at a temperature of 650-750°C yielded biochar, bio-oils and gas in the range of around 25-42%, 45-64% and 8-12%, respectively. Similarly, Sotoudehnia et al. [16] found a biochar yield of 34-75% and bio-oil yield of 9-47% from the pyrolysis of corrugated card-board, while Ibn Ferjani et al. [22] reported that grape marc pyrolysis from the wine industry at 500°C produced the highest biochar yields ($33%). Despite the growing body of research on the pyrolysis of various waste materials, studies specifically focusing on FW pyrolysis remain scarce. ...
The growing global demand for fish has led to an increase in fish waste (FW) production, necessitating efficient waste management strategies. Pyrolysis is a promising way to convert fish waste into high-value products. To achieve optimal waste mass reduction and gain insights into the pyrolysis process, estimating kinetic parameters is essential. This study investigated the pyrolysis of FW, Sardinella fimbriata, a previously unexplored waste source, using a thermogravimetric analyser. The study determined an average activation energy value of 84–124 kJ/mol using model-free isoconversional methods including Flynn-Wall–Ozawa, Kissinger–Akahira–Sunose, and Starink, whereas pre-exponential factor values were predicted to be between 102 and 1011 s−1. Further analysis using Criado's reduced master-plot approach showed that the experimental curves for pyrolysis coincided with many different theoretical plots for reaction mechanisms, with a concentration on reaction-order models. The analysis of thermodynamic parameters showed positive values of enthalpy change and Gibbs energy change for S. fimbriata FW pyrolysis, suggesting that the process is endothermic and non-spontaneous, while negative values of entropy change were observed across all conversion degrees as a result of the breakdown of complex organic molecules into simpler compounds. This study provides insights into the feasibility of thermal processes and offers new guidance for FW waste management and resource recovery, expanding the understanding of pyrolysis kinetics and thermodynamics for fish waste treatment.
... Furthermore, it is worth noting the importance of the exhausted grape marc (EGM) produced in distilleries. EGM still represents an underexplored feedstock, although its valuable energetic properties in the development of some bio-oils and bio-chars are well known (Ibn Ferjani et al., 2019, 2020. Moreover, some authors have reported the important bioactive compound (BAC) content found in EGM, mainly in the form of polyphenols (Salgado et al., 2014;Tacchini et al., 2019). ...
This article reports the first multistep combination of pulsed electric field (PEF; 3 kV/cm, 100 kJ/kg, 2 Hz, 100 ms) and supercritical fluid extraction (SFE) with CO2 (10–20 MPa, 25 mL/min [10% EtOH], 50 °C, 60 min) for exhausted grape marc (EGM). This current protocol was mainly created to recover bioactive glycosylated and lipidic compounds. In this regard, total antioxidant capacity (TAC) was enhanced up to 68% after PEF treatment compared to conventional soaking. However, re-extracting PEF-treated EGM after the application of SFE (PEF + SFE) boosted the efficiency by up to 87%. Several polyphenols (kaempferol, luteolin, scutellarin, and resveratrol, among others), together with other glycosylated structures, were identified by liquid chromatography coupled with mass spectrometry analysis. The bioactive lipidic compounds extracted by SFE, along with the carbohydrate fraction (free sugars) favourably extracted by PEF pre-treatment (mainly glucose, but also fructose and sucrose), were concurrently detected by nuclear magnetic resonance. The remaining solid fraction after treatment was also characterised. Different microscopic morphology was observed by scanning electron microscopy (SEM) on untreated, PEF, and PEF + SC–CO2–treated EGM. Differential thermogravimetric (DTG) curves determined by thermogravimetric analysis (TGA) also suggested alternative and potential means for the valorisation of this matrix.
... jp/ en/) with an external heating mechanism for cattle manure, chicken manure, and bamboo, at a carbonization temperature of approximately 400-500 °C for 2 h. A rotary kiln carbonizer (MES50, Kanazawa City, Ishikawa, Meiwa Co. Ltd., Japan) with an internal heating mechanism was used for slaughterhouse wastewater, rice husk, and woodchip carbonization at 400-500 °C for 30 min according to procedures outlined by Ferjani et al. (2019) and Song et al. (2012) (Suppl. Table 5 Additional information). ...
This study investigated the effect of the interaction between wood vinegar and biochar feedstock on total biomass, fruit weight (yield), and sugar content of tomato plants ( Solanum lycopersicum L . ). An experiment was conducted in two locations with six different biochar types produced from either plant or animal feedstock. Each biochar was incorporated into soil (1:2500 g/g) along with chemical fertilizer. Wood vinegar was diluted with water (1:200 mL) and applied once weekly for the vinegar treatment. Biochar application resulted in a higher yield and biomass of the chicken manure biochar owing to its high ammonium-nitrogen content. Vinegar application increased the yields of the plant feedstock, which was particularly evident for most of the yield parameters with the bamboo biochar. Regardless of treatment, yield and biomass were not significantly different between the animal and plant feedstock. The sugar content was higher for the chicken manure and animal litter biochar, which was attributed to better pH conditions. The combination of plant feedstock biochar and vinegar application for improving the yield of tomatoes is promising. In contrast, vinegar application could potentially limit the yield and fruit sugar content of tomato plants treated with animal feedstock biochar.
Highlights
• The soil was amended with biochar, with or without vinegar application.
• The chicken manure biochar plants had the highest yield and biomass.
• Vinegar application increased the yield of the plant feedstock.
• Plant and animal feedstock plants had similar yield and biomass.
• The pH of the animal feedstock was better because of higher CO 2 and MgO contents.
• Fruit sugar content for animal feedstock plants was better due to higher phosphorus.
... Furthermore, it is worth noting the importance of the exhausted grape marc (EGM) produced in distilleries. EGM still represents an underexplored feedstock, although its valuable energetic properties in the development of some bio-oils and bio-chars are well known (Ibn Ferjani et al., 2019, 2020. Moreover, some authors have reported the important bioactive compound (BAC) content found in EGM, mainly in the form of polyphenols (Salgado et al., 2014;Tacchini et al., 2019). ...
The circular economy considers waste to be a new raw material for the development of value-added products. In this context, agroindustrial lignocellulosic waste represents an outstanding source of new materials and platform chemicals, such as levulinic acid (LA). Herein we study the microwave (MW)-assisted acidic conversion of microcrystalline cellulose (MCC) into LA. The influence of acidic catalysts, inorganic salt addition and ball-milling pre-treatment of MCC on LA yield was assessed. Depolymerization and disruption of cellulose was monitored by FTIR, TGA and SEM, whereas the products formed were analyzed by HPLC and NMR spectroscopy. The parameters that afforded the highest LA yield (48 %, 100 % selectivity) were: ball-milling pre-treatment of MCC for 16 min at 600 rpm, followed by MW-assisted thermochemical treatment for 20 min at 190 °C, aqueous p-toluenesulfonic acid (p-TSA) 0.25 M as catalyst and saturation with KBr. These optimal conditions were further applied to a lignocellulosic feedstock, namely melon rind, to afford a 51 % yield of LA. These results corroborate the suitability of this method to obtain LA from agroindustrial wastes, in line with a circular economy-based approach.
... Therefore, the effects of the secondary reaction become significant, while at a low heating rate biochar is produced more [25]. Ibn Ferjani et al. showed that the biochar yield decreased with temperature and plateau at 500°C, the biochar yield was lowered at a high residence time [26]. The volatile matter is the matter loss when biomass is subjected to thermal degradation. ...
Biochar is a high carbon content organic compound has potential applications in the field of energy storage and conversion. It can be produced from a variety of biomass feedstocks such as plant based, animal based, and municipal waste at different pyrolysis conditions. However, it is difficult to produce biochar on a large scale if the relationship between the type of biomass, operating conditions, and biochar properties is not understood well. Hence, the use of machine learning based data analysis is necessary to find the relationship between biochar production parameters as well as feedstock properties with biochar energy properties. In this work, a rough set-based machine learning (RSML) approach has been applied to generate decision rules and classify biochar properties. The condition attributes were biomass properties (volatile matter, fixed carbon, ash content, carbon, hydrogen, nitrogen, oxygen) and pyrolysis conditions (operating temperature, heating rate residence time) while the decision attributes considered were yield, carbon content, and higher heating value. The rules generated were tested against a set of validation data and evaluated for its scientific coherency. Based on then decision rules generated, biomass with ash content of 11 to 14 wt%, volatile matter of 60 to 62 wt% and carbon content of 42 to 45.3 wt% can generate biochar with promising yield, carbon content and higher heating value via pyrolysis process at operating temperature of 425°C to 475°C. This work provided the optimal biomass feedstock properties and pyrolysis conditions for biochar production with high mass and energy yield.
... The biochar yield was found to be maximum at 300 and 400 °C, or around 65.8% and 59.1%, respectively, when exhausted grape marc was subjected to biomass pyrolysis temperatures of 300 °C to 700 °C. However, at temperatures of 500 °C and 700 °C, biochar yield significantly decreased, with 33.8% for the former and 30.9% for the latter (Ferjani et al. 2019). ...
Climate change issues are calling for advanced methods to produce materials and fuels in a carbon–neutral and circular way. For instance, biomass pyrolysis has been intensely investigated during the last years. Here we review the pyrolysis of algal and lignocellulosic biomass with focus on pyrolysis products and mechanisms, oil upgrading, combining pyrolysis and anaerobic digestion, economy, and life cycle assessment. Products include oil, gas, and biochar. Upgrading techniques comprise hot vapor filtration, solvent addition, emulsification, esterification and transesterification, hydrotreatment, steam reforming, and the use of supercritical fluids. We examined the economic viability in terms of profitability, internal rate of return, return on investment, carbon removal service, product pricing, and net present value. We also reviewed 20 recent studies of life cycle assessment. We found that the pyrolysis method highly influenced product yield, ranging from 9.07 to 40.59% for oil, from 10.1 to 41.25% for biochar, and from 11.93 to 28.16% for syngas. Feedstock type, pyrolytic temperature, heating rate, and reaction retention time were the main factors controlling the distribution of pyrolysis products. Pyrolysis mechanisms include bond breaking, cracking, polymerization and re-polymerization, and fragmentation. Biochar from residual forestry could sequester 2.74 tons of carbon dioxide equivalent per ton biochar when applied to the soil and has thus the potential to remove 0.2–2.75 gigatons of atmospheric carbon dioxide annually. The generation of biochar and bio-oil from the pyrolysis process is estimated to be economically feasible.
... This production of ethanol by grape marc generates another residue, i.e. exhausted grape marc (EGM). Ferjani et al. (2019) studied the utilization of EGM to produce biofuel and biofertilizer via pyrolysis. Similarly, various studies have been carried out on the recovery of grape marc through the pyrolysis technique (Xu et al., 2009;Casazza et al., 2016;Khiari and Jeguirim, 2018). ...
Circular bio-economy is a significant approach to resolving global issues elevated by environmental pollution. The generation of bioenergy and biomaterials can withstand the energy–environment connection as well as substitute petroleum-based materials as the feed stock production, thereby contributing to a cleaner and low-carbon-safe environment. Open discarding of waste is a major cause of environmental pollution in developing and under developed countries. Agricultural bio-wastes are obtained through various biological sources and industrial processing, signifying a typical renewable source of energy with ample nutrients and readily biodegradable organic substances. These waste materials are competent to decompose under aerobic and anaerobic conditions. The projected global population, urbanization, economic development, and changing production and consumption behavior result in bounteous bio-waste production. These bio-wastes mainly contain starch, cellulose, protein, hemicellulose, and lipids, which can operate as low-cost raw materials to develop new value-added products. Thus, this review discussed specifically the agricultural waste and valorization processes used to convert this waste into value-added products (biofuel, enzymes, antibiotics, ethanol and single cell protein). These value added products are used in the supply chain and enhance the overall performance of agriculture waste management, execution of circular bio-economy has attained significant importance and it explains a closed-loop system in which the potential resources remain in the loop, allowing them to be sustained into a new value.
... Also, biochar can effectively improve soil structure and fertility, reduce greenhouse gas emissions and alleviate the adverse effects of different stresses due to their high stability and beneficial physicochemical properties (Oliveria et al., 2017;Pariyar et al., 2020). Generally, sustainable agriculture can be achieved and evolved by producing biochar from agriculture residues and returning it to the soils (Ibn Ferjani et al., 2019). ...
The organic amendment of degraded soil in South East of Tunisia was used to restore the chemical, and physical properties of soil quality investigated in this study. Biochar derived from pyrolyzed green waste at 360°C was used like organic amendment. Nines randomized plots with one square meter of the area of each plot in three replicates have been installed in the Institute of Arid Area in Mednine South East of Tunisia, with two rates of biochar 20 and 40 t/ha were investigated: 20 tons/ha (B20) (2 kg/m²) and 40 tons/ha (B40) (4 kg/m²). The results showed that biochar had a positive effect on soil's physical and chemical properties compared to non-amended soil (Untreated soil). Biochar supply at rates of 20 and 40 tons/ha, causes a decrease in electrical conductivity to achieve 2.66 mS/cm for the B40 dose after 1 year of amendment, also a decrease in the bulk density at the surface layer (0-20 cm) has been registered, the total porosity which was decreased with depth. The hydraulic conductivity is favored by the incorporation of biochar in the soil which increases the volume of voids and tends to create preferential flow paths.
... These results indicated the amorphous nature of KB and reduced sp 2 domains in KB carbon structure, whereas PB ratio indicated its crystalline nature and increased sp 2 domains of graphite structure [28]. Raman spectra of KB exhibited very broad peaks (Fig. 2 (a)), and this behavior is basically owing to the presence of amorphous carbon structures in a high proportion [29]. Whereas sharp peaks of Raman spectra in the case of PB is attributed to the crystalline carbon form. ...
This study demonstrates two sustainable processes to produce electroactive biochars and their application in electroactive constructed wetlands (CWs) providing a circular route for biomass utilization and technology up-gradation for wastewater treatment along with electricity generation. With the use of Canna indica biomass generated CWs operation, the current study produced two different biochars that differ in their physico-(electro)chemical properties related to the preparation method used. This study used plasma based processing to produce ultrafast biochar (PB) within a few minutes resulting in more crystalline biochar with high electrical conductivity compared to the amorphous material produced by using the drum kiln processed biochar (KB) method. These biochars were used in developing electroactive constructed wetlands coupled with microbial fuel cells (CW-MFC) and were operated in batch mode together with commercial granular graphite (GG) substrate-based CW-MFC as control. PB was developed from high-temperature plasma processing in just 6.0 minutes, whereas KB was prepared in bulk amount from natural combustion process through kiln method and took 3-4 days before final biochar preparation. Electrical conductivity (EC) of the biochar and GG material were found to be in the order of PB>GG>KB, indicating PB as a highly conductive material that assisted in microbial electron transfer. Accordingly, the highest current and power densities of 628 mA/m³ and 126 mW/m³, respectively, were also achieved with PB. The highest COD removal was found in CW-MFC-GG microcosms of 72.42 ± 2.61 % followed by CW-MFC-KB and CW-MFC-PB of 72.32 ± 2.98 % and 59.91 ± 3.21 %, respectively.
... phosphorus (0.1-0.6%), nitrogen (0.5-2.7%), and organic carbon (40.2-58.2%) [158][159][160]. Moreover, del Pozo et al. (2021) investigated the recovery of phenolic compounds through the pyrolysis process as an alternative to conventional extraction [161]. ...
The wine industry is one of the most relevant socio-economic activities in Europe. However, this industry represents a growing problem with negative effects on the environment since it produces large quantities of residues that need appropriate valorization or management. From the perspective of biorefinery and circular economy, the winery residues show high potential to be used for the formulation of new products. Due to the substantial quantities of phenolic compounds, flavonoids, and anthocyanins with high antioxidant potential in their matrix, these residues can be exploited by extracting bioactive compounds before using the remaining biomass for energy purposes or for producing fertilizers. Currently, there is an emphasis on the use of new and greener technologies in order to recover bioactive molecules from solid and liquid winery residues. Once the bio compounds are recovered, the remaining residues can be used for the production of energy through bioprocesses (biogas, bioethanol, bio-oil), thermal processes (pyrolysis, gasification combustion), or biofertilizers (compost), according to the biorefinery concept. This review mainly focuses on the discussion of the feasibility of the application of the biorefinery concept for winery residues. The transition from the lab-scale to the industrial-scale of the different technologies is still lacking and urgent in this sector.
... Meanwhile, fast pyrolysis involves heating rate of >2 • C/s and residence period of less than 10 s (Dai et al., 2020b). The temperature range for slow and fast pyrolysis are 300-700 • C and 300-1000 • C, respectively (Foong et al., 2021;Ibn Ferjani et al., 2019). Sakhiya et al. (2022) prepared biochar from rice straw with slow pyrolysis in a batch-type pyrolysis reactor from 300− 500 • C with a residence time of 60 mins and a heating rate of 10 • C/min. ...
The valorization of biochar as a green and low-cost adsorbent provides a sustainable alternative to commercial wastewater treatment technologies that are usually chemical intensive and expensive. This review presents an in-depth analysis focusing on the rice straw-derived biochar (RSB) for removal of various types of contaminants in wastewater remediation. Pyrolysis is to date the most established technology to produce biochar. Subsequently, biochar is upgraded via physical, chemical or hybrid activation/modification techniques to enhance its adsorption capacity and robustness. Thus far, acid-modified RSB is able to remove metal ions and organic compounds, while magnetic biochar and electrochemical deposition have emerged as potential biochar modification techniques. Besides, temperature and pH are the two main parameters that affect the efficiency of contaminants removal by RSB. Lastly, the limitations of RSB in wastewater remediation are elucidated based on the current advancements of the field, and future research directions are proposed.
... The elements such as C and N in biochar differed significantly while obtained from pine trees, poultry manure, and peanut husk at 400 and 500 • C, respectively (El-Bassi et al., 2021). Furthermore, transferable phosphate, potassium, calcium, and magnesium were significantly higher in biochar produced at 500 • C than in biochar produced at 400 • C (Ferjani et al., 2019). The deviation was primarily associated with the high pyrolysis temperature, which enhanced raw material mineralization besides reduced CEC. ...
A number of anthropogenic and weathering activities accumulate heavy metals in soils, causing adverse effects on soil characteristics, microbial activity (diversity), agricultural practices, and underground aquifers. Controlling soil heavy metal pollution is difficult due to its persistence in soils, resulting in the deposition and transmission into the food web via agricultural food products, ultimately affecting human health. This review critically explores the potential for remediation of metal-contaminated soils using a biochar-based responsible approach. Plant-based biochar is an auspicious bio-based residue substance that can be used for metal-polluted soil remediation and soil improvement as a sustainable approach. Plants with rapid growth and increased biomass can meet the requirements for phytoremediation in large quantities. Recent research indicates significant progress in understanding the mechanisms of metal accumulation and contaminant movement in plants used for phytoremediation of metal-contaminated soil. Excessive contamination reduces plant biomass and growth, which has substantial hyperaccumulating possibilities and is detrimental to the phytoremediation process. Biochar derived from various plant sources can promote the growth and phytoremediation competence of native or wild plants grown in metal-polluted soil. Carbon-enriched biochar encourages native microbial growth by neutralizing pH and providing nutritional support. Thus, this review critically discusses the influence of plant and agricultural waste-based biochar on plant phytoremediation potential in metal-contaminated soils.
... They obtained highest biochar yield of 37.71 wt% at 300°C. Ferjani et al. (2019)., investigated the effect of pyrolysis temperatures, ranging from 300°C to 700 C on exhausted grape marc (EGM) on the biochar yield and physicochemical changes after undergoing the thermal conversion process. They found that at 300°C and 400°C, the biochar yield obtained were highest and were in the range of 65.8 %-59.1%, ...
The excessive dependency on fossil fuel resources could be curtailed by the efficient conversion of lignocellulosic biomass. Biochar, a porous carbonaceous product synthesized exploiting thermochemical conversion pathway, could be an environment-friendly replacement of fossil fuel resources. Slow pyrolysis, a sub-class among various thermochemical conversion techniques, has gained immense popularity owing to its potential to convert biomass to biochar. Furthermore, biochar obtained as the by-product of slow pyrolysis has attracted enormous popularity due to its proven role and application in the multidisciplinary areas of engineering and environmental remediation applications. The physicochemical quality of biochar and its performance is significantly dependent on the feedstock type and pyrolysis process parameters. Therefore, further experimental research and investigations in terms of lignocellulose biomass type and pyrolytic process parameters (temperature, heating rate and reaction time) are essential to produce biochar with desired physicochemical features for effective utilization. This review presents an updated report on slow pyrolysis of lignocellulosic biomass, impact of different pyrolysis parameters and degradation pathway involved in the evolution properties of biomass. The influence of the feedstock type and lignocellulosic composition on the biochar properties are also discussed meticulously. The co-relationship between biochar yield at different pyrolysis temperatures and the development of textural properties provides valuable information for their effective utilization as a functional carbon material. Additionally, an extensive study was undertaken to collate and discuss the excellent physicochemical characteristics of biochar and summarizes the benefits of biochar application for diverse industrial purposes. Biochar is acknowledged for its excellent physicochemical properties owing to the thermal treatment and as a result its prospective diverse industrial applications such as for soil treatment, carbon sequestration, adsorbent (wastewater treatment or CO 2 capture), producing activated carbon for gold recovery, energy storage and supercapacitor are summarized systematically in this review paper. For instance, biochar when applied in soil have shown improvement in soil respiration by 1.9 times. Furthermore, biochar when used to capture CO 2 from flue gas stream under post-combustion scenario has demonstrated superior capture performance (2.8 mmol/g) compared to commercial activated carbon. This paper identified the knowledge gaps and outlooks in the field of the advancements of biochar from slow pyrolysis for targeted engineering applications mainly in the field of environmental remediation and energy harvesting.
... The yeast extract was replaced by wine lees in order to reduce fermentation costs, which was possible to reach 59.4 g/L of mannitol for red must and 65.6 g/L for white must in 144 h. The compounds extracted from waste of winemaking are of great importance in several sectors (e.g., food, cosmetics, pharmaceuticals, biofertilizer, and energy [35,[37][38][39]. ...
Europe is considered the largest producer of wine worldwide, showing a high market potential. Several wastes are generated at the different stages of the wine production process, namely, vine pruning, stalks, and grape marc. Typically, these residues are not used and are commonly discarded. Portugal generates annually approximately 178 thousand metric tons of wine production waste. In this context, the interest in redirecting the use of these residues has increased due to overproduction, great availability, and low costs. The utilization of these lignocellulosic biomasses derived from the wine industry would economically benefit the producers, while mitigating impacts on the environment. These by-products can be submitted to pre-treatments (physical, chemical, and biological) for the separation of different compounds with high industrial interest, reducing the waste of agro-industrial activities and increasing industrial profitability. Particularly, vine-pruning residue, besides being a source of sugar, has high nutritional value and may serve as a source of phenolic compounds. These compounds can be obtained by bioconversion, following a concept of biorefinery. In this framework, the current routes of the valorisation of the pruning residues will be addressed and put into a circular economy context.
... 27 The liquid products, which obtain as a result of pyrolysis of waste polyethylene terephthalates (wPET) made in nitrogen and hydrogen gas environments in a batch reactor, are composed mainly of n-alkane, alkene, single ring aromatic compounds and polyaromatic compounds. 28,29 According to proximate and ultimate analysis, wPETs contain 0.3% moisture, 88.3% volatile matter and 11.4% fixed carbon (wt% daf), and approximately 62% carbon (C), 4% hydrogen (H) and 34% oxygen (O) (wt%). 30,31 C/H ratio has an important effect on transformation of plastics into the liquid and the gas products by thermal methods. ...
In this study, waste polyethylene terephthalate (wPET) was converted to liquid fuel by the pyrolysis method. It was also investigated both effects of microwave pre‐treatment and catalyst (sodium borohydride) on total conversion and oil + gas yield. The reaction temperature of 375–425°C and the reaction time of 30 min are sufficient for the pyrolysis of waste plastic samples in a batch reactor. In the pyrolysis of wPETs, the highest oil + gas yield of 45% was obtained under the conditions of reaction temperature of 425°C and reaction time of 30 min. The highest total conversion was 62% of microwave pre‐treated wPETs under catalytic conditions. It can be argued that microwave pre‐treatment and NaBH4 influence the oil + gas yield in pyrolysis experiments. According to the gas chromatography–mass spectrometry (GC–MS) analysis results of the oil products, they consist of aromatic, mono and multi‐ring aromatic compounds and polyaromatic compounds. Higher heating values of the solid products obtained in pyrolysis are approximately 4000–6000 cal/g. According to X‐ray diffraction analysis (XRD) of the solid products, they consist largely of crystalline terephthalic acid (C8H6O4).
... jp/ en/) with an external heating mechanism for cattle manure, chicken manure, and bamboo, at a carbonization temperature of approximately 400-500 °C for 2 h. A rotary kiln carbonizer (MES50, Kanazawa City, Ishikawa, Meiwa Co. Ltd., Japan) with an internal heating mechanism was used for slaughterhouse wastewater, rice husk, and woodchip carbonization at 400-500 °C for 30 min according to procedures outlined by Ferjani et al. (2019) and Song et al. (2012) (Suppl. Table 5 Additional information). ...
... Moreover, biochars have been valorized for soil remediation and amendment resulting in pollutants immobilization, improvement of soils' water holding capacity and fertility, crops growth and production yields, and decrease of greenhouse gas emissions from soils (Ayaz et al., 2021;Sri Shalini et al., 2020). However, a great limitation of the biochars' reuse in agriculture is their low N contents which are lost by volatilization during the pyrolysis process (El-Bassi et al., 2021;Haddad et al., 2020;Hadroug et al., 2019;Ibn Ferjani et al., 2019;Keskinen et al., 2021). The higher the pyrolysis temperature, the lower is the produced biochar's N content (Hadroug et al., 2021b;Hassan et al., 2020;Ibn Ferjani et al., 2020). ...
During the last decade, biochars have been considered as attractive and eco-friendly materials with various applications including wastewater treatment, energy production and soil amendments. However, the important nitrogen losses during biochars production using the pyrolysis process have limited their potential use in agriculture as biofertilizer. Therefore, it seems necessary to enrich these biochars with nitrogen sources before their use in agricultural soils. This paper is the first comprehensive review on the assessment of biomass type and the biochars' properties effects on N recovery efficiency from aqueous solutions as well as its release and availability for plants when applying the N-enriched chars in soils. In particular, the N recovery efficiency by raw biochars versus the type of the raw feedstock is summarized. Then, correlations between the adsorption performance and the main physico-chemical properties are established. The main mechanisms involved during ammonium (NH4–N) and nitrates (NO3–N) recovery process are thoroughly discussed. A special attention is given to the assessment of the biochars physico-chemical modification impact on their N recovery capacities improvement. After that, the application of these N-enriched biochars in agriculture and their impacts on plants growth as well as methane and nitrous oxide greenhouse gas emissions reduction are also discussed. Finally, the main future development and challenges of biochars enrichment with N from wastewaters and their valorization as biofertilizers for plants growth and greenhouse gas (GHG) emissions reduction are provided. This systematic review is intended to promote the real application of biochars for nutrients recovery from wastewaters and their reuse as eco-friendly fertilizers.
... Up to 20% of the harvested wine grape becomes waste during wine production. Grape marc can be used for compost and substrate in ornamental plants (Madjar et al., 2014a) and vegetables (Carmona et al., 2012), as well as for obtaining biofuel (Xu et al., 2009) and biochar (Ibn Ferjani et al., 2019). The use of vine pruning materials in pyrolysis processes solves several environmental problems, including managing large volumes of waste generated annually and reducing CO2 emissions during uncontrolled waste burning (Nunes et al., 2021). ...
Plant wastes are often burned, leading to air pollution and significant loss of potential soil nutrients. In order to mitigate these drawbacks, the waste can remain or be added to the soil, but this may increase crop diseases and also greenhouse gas (GHG) emissions (e.g., CO2, CH4, N2O). Pyrolysis of vine waste is a promising and relevant technique, and the obtained biochar can be further used as a soil amender, can enhance soil C sequestration and water holding capacity, reduce GHG emissions and nutrient leaching, increase soil fertility, resulting in agronomic, environmental, and economic benefits. The aim of this study was to characterise vine waste from a physicochemical point of view in order to be used as raw material for producing biochar, which will be applied as soil amender. Plant waste material (grapevine prunings and marc) was received from Pietroasa-Istrita Research Station for Viticulture. The materials were characterised in terms of dry matter, loss on ignition, surface morphology, total carbon and nitrogen, bulk density, water holding capacity, pH, electrical conductivity, and mineral content. The obtained results indicate that grapevine prunings and marc are suitable materials for obtaining biochar.
... Nowadays, the common use of grape pomace can be as fertilizers, heat producers and cattle feed [4,5]. In addition, there is evidence about the use of grape pomace as biofuels and biofertilizers [6]. However, these applications have some limits. ...
Grape pomace is a winery by-product that is more and more valorized as a source of healthy bioactive molecules such as polyphenols. In addition, it can be used to produce some alcoholic beverages, such as grappa, which is a typical distilled Italian alcoholic product. The spent grape pomace after grappa elaboration is mainly considered a food waste. The aim of this study was to reconsider and valorize red and white pomaces obtained after the production of grappa. The total phenolic content of both samples, as well as the antioxidant activity had a decrease after the distillation; however, it was not significant in the case of red pomace. Regarding the phenolic profile, the behavior during the distillation was different, according to the type of pomace. After the grappa production, catechins and epicatechins were the most significant phenolics in white and red pomace, respectively, demonstrating the remaining bioactivity of this by-product, which could be useful within the food industry.
... Condensation of tiny aromatic amorphous carbon structures results in D structures. These findings are consistent with the results observed for exhausted grape marc char after various thermal treatments [72], see Fig. 9. This behavior can be due to the significant amount of amorphous carbon structures formed during low-temperature pyrolysis [57]. ...
The aim of this review is to investigate the recent development of kenaf derived biochar and its composites in various engineering and agricultural applications including nanostructure catalysts and polymer composites as kenaf biochar and activated carbon are mainly used as material adsorbents and soil amendments. A systematic review on the effect of process parameters of thermal decomposition, pyrolysis towards the production of desired biochar, therefore, is in crucial needs. Based on existing literature, the properties and production of kenaf biomass and resultant biochar are discussed in this paper. This analysis focuses on the unique characteristics of kenaf crops and the resulting biochar, which has a surprisingly large surface area and increased pore volume, to explain their prospective applications, whether in environmental utilization or engineering applications. Range of optimum surface areas for kenaf biochar are around 800–1000 m2/g where they show high adsorption properties. Whereas, the pore volume of activated carbon usually exceeds 1 cm3/g. Recent developments in engineered kenaf biochar technology and its future directions for research and development are also discussed.
The effects of pyrolysis temperature and heating rate on yield and quality properties of biochar obtained from grape pomace were investigated. Surface properties and heat values were determined in addition to proximate and elemental analyses. Experiments were made at the conditions of 400, 500 and 600 °C pyrolysis temperature and 200, 400 and 600 C/min heating rate. Increase of pyrolysis temperature and heating rate decreased the biochar yield. There was a general decrease in the moisture values of the biochar samples and an increase in the ash content with increasing of pyrolysis temperature. Heating value, fixed carbon content and volatile matter content of the biochar samples changed between 24.92-28.62 MJ/kg, 60.18-74.02%, and 8.59-28.97%, respectively. Elemental analyses results showed that contents of C, H, O, N were determined between 71.23-80.34%, 2.80-5.06%, 0-12.9%, and 2.04-2.93%, respectively. SEM images of raw material namely grape pomace and biochar samples showed that increase in the number of pores occurred with the pyrolysis process.
Agricultural waste management poses a significant challenge due to increasing generation rate of this residue, necessitating the development of solutions to minimize various problems in this context. Among the potential possibilities, pyrolysis stands out as a promising technology due to its low operational costs, simplicity of operation, and the production of several value-added products, including solids (biochar), liquids (pyroligneous extracts: pyroligneous acid and bio-oil), and gaseous (non-condensable gases). This work aimed to synthesize the recent advances and potential uses for the products obtained from the pyrolysis of agricultural wastes, with a particular focus on the emerging applications of the liquid fraction. To achieve the purpose of this review, a bibliographic portfolio was created using a state-of-the-art approach, utilizing Scopus as the database. The yields and uses of pyrolysis products vary according to operational parameters, such as temperature, heating rate, residence time, reactor, agro-waste characteristics, and others. These products have diverse potential applications, including environmental uses (soil remediation, wastewater treatment, and bioenergy), pharmaceutical purposes (antimicrobials, antioxidants, anti-inflammatories), food industry uses (preservatives and smoke flavor), and applications in agriculture and livestock (plant growth promotion, pest and disease control, feed additive, and soil conditioner). Therefore, pyrolysis is a promising technology for the valorization of agricultural wastes, promoting various aspects of the circular economy and providing a sustainable solution to obtain several value-added products with diverse applications from this thermochemical conversion process.
Biochar is emerging as a potential solution for biomass conversion to meet the ever increasing demand for sustainable energy. Efficient management systems are needed in order to exploit fully the potential of biochar. Modern machine learning (ML) techniques, and in particular ensemble approaches and explainable AI methods, are valuable for forecasting the properties and efficiency of biochar properly. Machine‐learning‐based forecasts, optimization, and feature selection are critical for improving biomass management techniques. In this research, we explore the influences of these techniques on the accurate forecasting of biochar yield and properties for a range of biomass sources. We emphasize the importance of the interpretability of a model, as this improves human comprehension and trust in ML predictions. Sensitivity analysis is shown to be an effective technique for finding crucial biomass characteristics that influence the synthesis of biochar. Precision prognostics have far‐reaching ramifications, influencing industries such as biomass logistics, conversion technologies, and the successful use of biomass as renewable energy. These advances can make a substantial contribution to a greener future and can encourage the development of a circular biobased economy. This work emphasizes the importance of using sophisticated data‐driven methodologies such as ML in biochar synthesis, to usher in ecologically friendly energy solutions. These breakthroughs hold the key to a more sustainable and environmentally friendly future.
Phytoremediation is one of the cheapest and most widely used technologies for stabilizing and extracting pollutants from contaminated sites. Recently, a variety of solutions, such as the use of different elements, compost, nanoparticles, microorganisms, etc., have been explored for improving and accelerating the phytoremediation process. Biochar has also gained attention for its affordability, abundance, ability to improve soil structure and plant morpho-physiology and biochemistry, lack of environmental hazards, etc. As a first step, this study aimed to provide an overview of biochar’s properties, and operation by identifying the method of production and examining the differences between different types of biochar. Following that, by examining various factors that pollute the environment, the influence of different types of biochar on phytoremediation efficiency was explored. Also, in this study, an attempt has been made to examine the effect of the combination of biochar with other factors in improving the phytoremediation of pollutants, as well as the use of the residues of phytoremediation for the production of biochar, so that future research can be planned based on the results obtained.
Straw mulching is a sustainable practice used to control soil erosion. However, different doses of mulch affect the efficiency of straw conservation. This study presents detailed research on how soil physicochemical properties and the hydrological response react to different types of vineyard soil management (Tilled, Grass, Low Straw, High Straw) and seasons (spring, summer, autumn) under conventional management on Anthrosols in Mediterranean conditions. To assess soil properties, core samples and disturbed samples were taken from the topsoil layer (0–10 cm). To evaluate erosion rates, a rainfall simulation experiment was conducted (58 mm h−1 for 30 min) with 10 replicates per treatment and season (120 in total). The results show higher water-stable aggregates (WSA) and soil organic matter (SOM) and lower bulk density (BD) in the mulch and grass treatment groups compared with the Tilled treatment group. High Straw treatment successfully mitigated runoff, while other treatments had significantly higher runoff that triggered sediment loss (SL) and translocation of P, K, Zn and Ni down the slope. There were 254% and 520% higher K losses with Tilled treatment in autumn compared with Low Straw and Grass treatments, respectively. Statistical analysis showed a strong association between element loss and SL, which indicates an ecological threat in degraded and endangered vineyards. Mulch application and grass cover reduce the vulnerability of vineyards, reduce evaporation, act as insulation against high temperatures, reduce erosion and suppress weed growth. The mulch dosage varies depending on the goals and conditions of the vineyard; thus, lower mulch dosage (2 t/ha) is appropriate when soil conditions are favourable and there is no significant need for moisture retention, while higher mulch dosage is necessary in dry regions to maintain soil moisture during high-temperature periods, as well as in sloped areas subjected to erosion.
In this work, a valorisation of olive and wine industry co-products (olive pomace and grape marc, respectively) through different thermochemical processes is studied. The characterization of olive pomace and grape marc is made to evaluate which thermochemical process is more suitable for each type of biomass and a specific application. Then, a life cycle assessment (LCA) of olive pomace value chain is made to assess the environmental impacts. Several scenarios of biomass conversion process were considered: combustion, gasification and hydrothermal carbonization (HTC) followed by gasification to generate electricity; and pyrolysis to produce biochar, bio-oil and syngas. Finally, a techno-economic analysis was performed for each mentioned scenario to evaluate the feasibility and conclude which scenario is more economically advantageous. Results suggest that valorisation of olive pomace might be more suitable through the gasification process and grape marc through the pyrolysis process. From the LCA was possible to conclude that combustion scenario has the highest environmental impact. In comparison, gasification, HTC and pyrolysis presented a lower impact with a value of 69.45%, 50.96% and 40.97%, respectively, considering combustion as 100% impact. Regarding the techno-economic analysis, several scenarios have promising results with some scenarios with payback periods inferior to 5 years. The only exception is HTC followed by gasification which in current days is not competitive with other technologies. Overall gasification and pyrolysis are promising alternatives to the valorisation of olive pomace and grape marc. The drying process has an important role in terms of environmental impact and economic viability.
The current study explored the bioenergy potential of waste miscanthus grass (WMG). The kinetic study of WMG was evaluated via two model-free methods, in a thermogravimetric analyzer (TGA), at dynamic heating rates under an inert ambiance. The pyrolysis was performed in a semi-batch fixed bed reactor at 500 oC, 80 oC min heating rate, and 1 mm particle size. The evolution of hot vapors during pyrolysis was explored using a TGA-FTIR analyzer. Finally, the bio-oil and biochar were characterized by their physicochemical properties. The kinetic results established that WMG followed a multi-step decomposition process, and the average activation energy gained from KAS and ST was found to be 197.66 and 179.64 kJ mol-1, respectively. TGA-FTIR study revealed the foremost release of carbon dioxide (28.22%), followed by a carbonyl (25.40%), and ether (19.12%). Further, the pyrolysis of WMG yielded 29.32 wt. % of bio-oil at the optimized condition whereas, physicochemical results of bio-oil established; 65.16% carbon content, 26.16 MJ kg-1 HHV, 34.15 cP viscosity, and 812 kg m-3 density. GC-MS study of bio-oil confirmed the maximal release of hydrocarbons and phenols. Finally, characterization results of miscanthus grass biochar (MGB) demonstrated an excellent feedstock for industrial and domestic applications.
Despite the huge amounts of grape marc generated in Tunisia from the wine industry, very few efforts have been exerted to manage this harmful waste. Therefore, thermal processes may contribute to an environmental friendly management and also help winemakers to create new economic profitable circuits in an increasingly competitive context. Among the various thermochemical conversion process, pyrolysis is suitable for the recovery of food processing residues, due to their high minerals content and ability to create high added values of the derived products (biochar, bio-oil and syngas). In this context, the aim of this work is to optimize the pyrolysis process in order to benefit from the grape marc potential for achieving highest product yields. Therefore, physico-chemical and energy characteristics of grape marc issued from a Tunisian wine cooperative were determined according to international standards. Thermogravimetric analyzes were also performed to predict the grape marc behavior during degradation under an inert atmosphere. The profile of the mass loss rate shows two decomposition peaks corresponding to the cellulose and lignin decomposition. These peaks are shifted to lower temperatures comparing to several lignocellulosic biomass feedstocks due to high content of minerals that may play a catalytic role in the thermal degradation process. The biochar yield was about 40%, which was never met in literature for agricultural biomass in slow pyrolysis. Such behavior may be attributed to high lignin content in grape marc. Activation energies were calculated using integral Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods and differential Friedman method. The obtained values were 226.8, 224.2 and 229.5 kJ/mol, respectively. Such kinetics data are crucial in the design of the pyrolyzer for Tunisian grape marc recovery.
Solid char is a product of biomass pyrolysis. It contains a high proportion of carbon, and lower contents of H, O and minerals. This char can have different valorization pathways such as combustion for heat and power, gasification for Syngas production, activation for adsorption applications, or use as a soil amendment. The optimal recovery pathway of the char depends highly on its physical and chemical characteristics. In this study, different chars were prepared from beech wood particles under various pyrolysis operating conditions in an entrained flow reactor (500–1400 °C). Their structural, morphological, surface chemistry properties, as well as their chemical compositions, were determined using different analytical techniques, including elementary analysis, Scanning Electronic Microscopy (SEM) coupled with an energy dispersive X-ray spectrometer (EDX), Fourier Transform Infra-Red spectroscopy (FTIR), and Raman Spectroscopy. The biomass char reactivity was evaluated in air using thermogravimetric analysis (TGA). The yield, chemical composition, surface chemistry, structure, morphology and reactivity of the chars were highly affected by the pyrolysis temperature. In addition, some of these properties related to the char structure and chemical composition were found to be correlated to the char reactivity.
Biochar produced by pyrolysis of biomass can be used to counter nitrogen (N) pollution. The present study investigated the effects of feedstock and temperature on characteristics of biochars and their adsorption ability for ammonium N (NH4+-N) and nitrate N (NO3--N). Twelve biochars were produced from wheat-straw (W-BC), corn-straw (C-BC) and peanut-shell (P-BC) at pyrolysis temperatures of 400, 500, 600 and 700°C. Biochar physical and chemical properties were determined and the biochars were used for N sorption experiments. The results showed that biochar yield and contents of N, hydrogen and oxygen decreased as pyrolysis temperature increased from 400°C to 700°C, whereas contents of ash, pH and carbon increased with greater pyrolysis temperature. All biochars could sorb substantial amounts of NH4+-N, and the sorption characteristics were well fitted to the Freundlich isotherm model. The ability of biochars to adsorb NH4+-N followed: C-BC>P-BC>W-BC, and the adsorption amount decreased with higher pyrolysis temperature. The ability of C-BC to sorb NH4+-N was the highest because it had the largest cation exchange capacity (CEC) among all biochars (e.g., C-BC400 with a CEC of 38.3 cmol kg-1 adsorbed 2.3 mg NH4+-N g-1 in solutions with 50 mg NH4+ L-1). Compared with NH4+-N, none of NO3--N was adsorbed to biochars at different NO3- concentrations. Instead, some NO3--N was even released from the biochar materials. We conclude that biochars can be used under conditions where NH4+-N (or NH3) pollution is a concern, but further research is needed in terms of applying biochars to reduce NO3--N pollution.
http://eusoils.jrc.ec.europa.eu/esdb_archive/eusoils_docs/other/EUR24099.pdf
Activated carbon was produced from banana empty fruit bunch (BEFB) and Delonix regia fruit pod (DRFP) through single step chemical activation process. As both the lignocellulosic wastes showed maximum weight loss at temperatures lower than 500°C, they were carbonized at 450°C (BEFP) and 400°C (DRFP) respectively after impregnating with H 3 PO 4 and KOH. Highest yield of 41.09% was recorded in DRFP treated with H3PO4 followed by other treatments. The KOH treated DRFP recorded maximum bulk density of 0.46 g/ml followed by H 3 PO 4 treated DRFP. The BEFP carbons displayed lower attrition values than DRFP carbons. While the H 3 PO 4 treated DRFP carbon sample showed higher surface area, the untreated DRFP registered higher pore volume. However BET surface area was comparatively low in both the substrates. FT-IR analysis of H 3 PO 4 , KOH and untreated carbon sample, though did not show much difference in surface functional groups, showed shifts in bands and changes in wave numbers and absorbance between the untreated and treated samples indicating chemical transformations during pyrolysis. While highest iodine removal was observed in KOH treated BEFP and DRFP samples, methylene blue reduction was high in H 3 PO 4 , KOH and untreated BEFP carbon samples.
The application of bio-char (charcoal or biomass-derived black carbon (C)) to soil is proposed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems. Apart from positive effects in both reducing emissions and increasing the sequestration of greenhouse gases, the production of bio-char and its application to soil will deliver immediate benefits through improved soil fertility and increased crop production. Conversion of biomass C to bio-char C leads to sequestration of about 50% of the initial C compared to the low amounts retained after burning (3%) and biological decomposition (∘C common for pyrolysis). Existing slash-and-burn systems cause significant degradation of soil and release of greenhouse gases and opportunies may exist to enhance this system by conversion to slash-and-char systems. Our global analysis revealed that up to 12% of the total anthropogenic C emissions by land use change (0.21 Pg C) can be off-set annually in soil, if slash-and-burn is replaced by slash-and-char. Agricultural and forestry wastes such as forest residues, mill residues, field crop residues, or urban wastes add a conservatively estimated 0.16 Pg C yr−1. Biofuel production using modern biomass can produce a bio-char by-product through pyrolysis which results in 30.6 kg C sequestration for each GJ of energy produced. Using published projections of the use of renewable fuels in the year 2100, bio-char sequestration could amount to 5.5–9.5 Pg C yr−1 if this demand for energy was met through pyrolysis, which would exceed current emissions from fossil fuels (5.4 Pg C yr−1). Bio-char soil management systems can deliver tradable C emissions reduction, and C sequestered is easily accountable, and verifiable.
Grape stalk is an organic waste produced in great amounts in the industrialization processes of grape. This work presents the results of studies carried out to use this waste as raw material to prepare activated carbon through the physical and chemical route. The physicochemical characterization of this material suggests the presence of unusually high levels of ashes. Metal content was determined and high levels of potassium, sodium, iron, calcium and magnesium in carbonized and raw grape stalk were exhibited. This characteristic made difficult physical activation at high temperatures. A leaching step was included before the activation with steam, and adsorbents with surface areas between 700 and 900 m(2)/g were obtained. Physical activation was also performed at lower temperatures using carbonized grape stalk without leaching, leading to the development of some grade of porosity, with an area of 412 m(2)/g. These results would indicate the catalytic effect of the minerals present in this raw material. Chemical activation using phosphoric acid as activating agent seemed to be a very efficient method as final products with BET areas between 1000 and 1500 m(2)/g were obtained.
The composting of winery waste is an alternative to the traditional disposal of residues, and also involves a commitment to reducing the production of waste products. We studied two residues (sludge and grape stalks), mixed in two proportions (1:1 and 1:2 sludge and grape stalks (v/v)), and we also examined the effects of grinding the grape stalks. Our results showed that composting the assayed materials was possible. Best results were obtained in the compost heap in which the residues were mixed in the proportion 1:2, and where the grape stalks had been previously ground. Optimum results required a moisture around 55% and a maximum temperature around 65 degrees C and an oxygen concentration not lower than 5-10%. The resulting compost had a high agronomic value and is particularly suitable for the soils of the vineyards which have a very low organic matter content. The compost can be reintroduced into the production system, thereby closing the residual material cycle.
Biomass is increasingly being recognized as a promising carrier for both heat, energy and chemicals production. However, several aspects still require intense research activity towards a better design and optimization of industrial combustors, gasifiers and pyrolyzer. The objective of this work is to update the CRECK kinetic mechanism of biomass pyrolysis, allowing a better prediction of both yield and composition of the solid residue (biochar). Moreover, further model modifications allow to better describe the variability of hemicellulose in different biomass. To this end, a large set of literature experimental data is collected and organized into a database, which is used to further tune and validate the proposed kinetic mechanism. Although the kinetic model maintains the previous agreement in respect of the rate of biomass pyrolysis, formation and distribution of gas and tar products, the novelty of this work is the greater attention to the predictions of biochar yield and composition, in a wide range of operative conditions. The model describes the solid residue as a mixture of pure carbon together with lumped metaplastic compounds, which represent the whole range of oxygenated and hydrogenated groups bonded to the carbonaceous matrix. These metaplastic species are released to the gas phase with their own kinetics and describe the change of both mass loss and elemental composition of the biochar. These comprehensive predictions of biochar composition are crucial for an accurate description of the successive oxidation and gasification processes.
This investigation has established a complete environmentally friendly strategy for the valorization of olive mill wastewater (OMW). This valorization process includes different steps, namely, OMW impregnation on sawdust, drying, biofertilizer production, and soil amendment. The OMW impregnation on raw cypress sawdust (RCS) was performed using batch procedure mode. During this impregnation, 59% and 71% of the chemical oxygen demand and total dissolved salts of OMW were adsorbed on RCS. The drying of the impregnated sawdust (IS) and OMW was realized in a convective dryer at temperature ranging between 40 and 60 °C and air velocity ranging between 0.7 and 1.3 m/s. Comparison between both samples demonstrated clearly that the impregnation procedure accelerated the drying process and consequently allowed an ecologic recovery of water from OMW that could be reused. The IS sample was pyrolyzed at 500 °C for green fuel (bio-oil, gas) and char production. This residual char (IS-Char) exhibited higher mass fraction of 34.5%. The IS char characterization showed the presence of important nutrients (potassium, nitrogen, and phosphorus) contents. The application of the IS char as a biofertilizer for rye-grass growth studies under controlled conditions showed promising results in terms of leaf dimensions and mass yields of the plant. These preliminary results indicated the validity of the established strategy to convert OMW from a pollutant to green fuels, agricultural water source, and biofertilizer.
The goal of the present research is to study the effect of the inorganic species on the pyrolysis mechanism of lignocellulosic biomass. Many contradictions as the catalytic role of inorganic salts characterize the research works published up to now. These ambiguities are reasonably due to the morphological and structural modifications of the reacting biomass by the various demineralization and impregnation methods, that impact on the pyrolysis mechanism. In order to clarify the effect of inorganics on the pyrolysis mechanism, alkali and alkaline earth (AAEM) containing salts were deposited by impregnation method on cypress sawdust. Nuclear magnetic resonance analyses showed that the biomass structure was preserved and that metal deposition passes through a cationic exchange mechanism.
The influence of pyrolysis conditions on the structure properties and chemical composition of biomass chars was examined. The Raman spectroscopy ID/IG and IV/ID parameters were found to be correlated for pyrolysis temperatures higher than 600 °C. Furthermore, a correlation between IV/ID and the atomic ratio (O+H)/C was identified. These findings would corroborate the assumption that the large carbonaceous structures having defects (D band) would probably form from the condensation of the small amorphous ones (V region). The condensation of these small structures into larger ones would be accompanied by the release of H and O atoms into the gas phase.
In this work, winery industry wastes were valorised through the extraction of high added value compounds (polyphenols), followed by thermal conversion of the exhausted solid residues. For this purpose, three different temperatures (623, 723 and 823 K) were tested. The increase of the heat treatment temperature resulted in a significant increment in gas production containing methane and other hydrocarbons. Lipophilic liquid product quantity in grape marc was limited both before and after the polyphenol extraction. The recovery of phenolic compounds before the thermal treatment notably decreases the chemical oxygen demand level of the resulting hydrophilic liquid fraction. The pyrolysis residue represents from 30 to 55% of the initial mass but corresponds to a relevant decrease of its volume, and can be considered a good source of graphitic carbon with higher calorific value with respect to the initial grape waste and applicable for energy production.
Biochar produced during the thermochemical decomposition of biomass not only reduces the amount of carbon emitted into the atmosphere, but it is also an environment-friendly replacement for activated carbon and other carbon materials. In this review paper, researches on biochar are discussed in terms of production method and application. Different processes for biochar production, such as pyrolysis, gasification, hydrothermal carbonization, etc., are compared. Physical and chemical activation methods used to improve the physicochemical properties of biochar and their effects are also compared. Various environmental application fields of biochar including adsorption (for water pollutants and for air pollutants), catalysis (for syngas upgrading, for biodiesel production, and for air pollutant treatment), and soil conditioning are discussed. Recent research trend of biochar in other applications, such as fuel cell, supercapacitor, and hydrogen storage, is also reviewed.
In Tunisia, seasonal and centralized discharges of tomato waste and grape marc generated from agri-food industries have negative effects on the environment. Characterization of these residues shows that their calorific values are suitable for their energy recovery. However, the high mineral contents and the low bulk densities limit their direct use as biofuel. Therefore, a blending process using sawdust followed by densification into pellets is proposed for the recovery of these agri-food residues. Such strategy allows the pellets to meet standard requirements of the biofuels market. Furthermore, the performance of the pellets is evaluated during combustion tests in domestic boiler. The combustion parameters, the gaseous and particulate matter emissions are analyzed. Results indicate that the pellets prepared from agri-food residues have boiler and combustion efficiencies comparable to wood pellets. However, gaseous and particulate emissions are strongly affected by the operating parameters of the domestic boilers. Therefore, these parameters such as mass flow of water in the heat exchanger, combustible mass flow, primary and secondary inlet air flow should be adapted to each agri-food residue to benefit from these resources without leading to negative environmental impacts.
Vineyard waste and wastewater generated from wineries present significant risks to the environment if untreated. In this study, we carried out anaerobic co-digestion of grape marc and winery wastewater for energy production in the form of methane and material recovery. The results showed that milling the grape marc prior to being suspended in winery wastewater and inoculated with activated sludge in a 15 weeks batch digestion resulted in the production of 5.04 MJ/kg VS of energy compared with 0.97 MJ/kg VS from the non-milled treatment. Milling of grape marc also showed reduced CO 2 emission, 4.95 l/kg VS compared with 9.96 l/kg VS from non-milled samples. The results suggest that physical pre-treatment of grape marc results in bioenergy production which is comparable to many other organic waste streams such as cattle slurry, hen litter and food processing waste offering significant potential for utilisation by the winery industry.
Mediterranean countries generate large amounts of olive oil byproducts mainly OMWW (olive mill wastewater) and EOSW (exhausted olive solid waste). Although solid residues have various valorization strategies, there is no economically viable solution for the OMWW disposal. This study aims to recover the OMWW organic contents through solid biofuels production. Hence sawdust and EOSW were used for the OMWW impregnation. The potential of the obtained samples, namely: IS (impregnated sawdust) and IEOSW (impregnated exhausted olive solid waste) were evaluated. Therefore, the physicochemical characterizations and thermogravimetric analyses of the samples were first performed. Secondly, the samples densification into pellets and their combustion in a domestic combustor were carried out. Combustion efficiencies, gaseous and PM (particulate matter) emissions as well as ash contents were evaluated.
The analysis finding shows that addition of OMWW leads to an increase of energy content through the heating values increase. An increase of the impregnated samples reactivity was observed and assigned to the potassium catalytic effect. Combustion performances show that the OMWW addition has not a negative effect on their firing quality. Moreover, a beneficial effect on the pollutant emissions is observed with IEOSW pellets. The developed strategy constitutes a promising issue for the OMWW disposal and recovery.
To compensate for the shortcomings of manure biochar, an ignocellulose-based feedstock (rice straw) was added into manure-based feedstock (swine manure) at 3:1, 1:1 and 1:3 (w/w) manure/straw ratios during biochar production within the pyrolysis temperature ranging from 300-700 ˚C. The results showed that the pyrolysis temperatures and the proportions of straw added both influenced the biochar properties. The overall properties of biochars at 300 ˚C, 400 ˚C and 500 ˚C were thoroughly different from those at 600 ˚C and 700 ˚C by principal components analysis (PCA). The XRD, FTIR and SEM spectra suggested that the addition of straw considerably changed the mineral crystals, functional groups and porous structures in manure biochar, respectively. The Zn(Ⅱ) adsorption batch experiments showed that the biochars with more proportions of manure had the largest Zn(Ⅱ) adsorption capacity than other biochars at 300 ˚C, which was attributed to the mineral components, oxygen functional groups and surface areas. To meet varied agronomic and environmental requirements, the different conditions including pyrolysis temperatures and proportions of straw added should be quantitated.
This paper aims to analyse energy related properties, thermal degradation behaviour and devolatilization kinetics of five Cameroonian biomasses namely, Palm Kernel Shells (PKS), Mesocarp Fibres (PMF), Coffee Husk (CH), Corn Cob (CC) and Peanut Shell (PNS). The thermal degradation was performed using thermogravimetric analysis (TG). Different behaviours related to the presence of chemical constituents such as cellulose, hemicellulose and lignin were obtained. Comparison of the thermal characterization shows that PMF is the most interesting feedstock with the highest heating values and reactivity due to higher volatile content. Decomposition of TG data was analysed by applying diffusion and chemical reaction kinetic models. Obtained results show that biomass pyrolysis is represented by two successive steps. The devolatilization stage characterized by high weight loss rate is well described by diffusion reaction models. In contrast, the char formation stage characterized by low weight loss rate is well described by third order chemical reaction models.
Spent coffee grounds (SCG), a processing by-product from the coffee industry, were evaluated as a potential feedstock for preparing agropellets for energy production. Hence, pure SCG and a SCG/Sawdust blend were transformed into pellets. The latter thermal and chemical properties such as calorific value, ash content, bulk density, fixed carbon and elemental analysis were obtained. Thermogravimetric analyses were conducted in order to determine pyrolysis kinetics and combustion characteristics in order to study the agropellets performance.
The obtained results show that SCG pellets thermal characteristics are in the same order as conventional biomasses such as sawdust. Moreover, Blend 50% SCG/50% sawdust reaches the superior NF agropellets standard requirements which are essential to sell this agropellets in the French market. Analysis of the thermal degradation shows that SCG and its blend follow the usual behaviour of lignocellulosic materials. Comparison of the combustion characteristics shows a higher reactivity of the blend comparing to pure SCG and sawdust. Such behaviour might relate to heterogeneous structure and mutual interaction of the individual components of SCG and sawdust. Pyrolysis kinetics parameters obtained for SCG and SCG/Sawdust blend are fairly close agreement with those found in literature for different biomasses. Hence SCG/Sawdust may be a promising biofuel for the energy production in industrial applications.
The production of food waste covers all the food life cycle: from agriculture, up to industrial manufacturing and processing, retail and household consumption. In developed countries, 42% of food waste is produced by households, while 39% losses occur in the food manufacturing industry, 14% in food service sector and remaining 5% in retail and distribution. Increasingly, industrial ecology concepts such as cradle to cradle and circular economy are considered leading principle for eco-innovation, aiming at “zero waste economy” in which waste are used as raw material for new products and applications. The large amount of waste produced by the food industry, in addition to being a great loss of valuable materials, also raises serious management problems, both from the economic and environmental point of view. Many of these residues, however, have the potential to be reused into other production systems, trough e.g. biorefineries. The present work focuses on the use of food waste coming from food manufacturing (FWm). Through extensive literature review, the authors present feasibility and constraints of applying industrial symbiosis in recovering waste from food processing, focusing on recycling (excluding energy recovery) of the solid and liquid waste from food processing industry. The main uses of functional ingredients derived from this transformation are presented and discussed, highlighting mainstream sectors of application, e.g. in the nutraceutical and pharmaceutical industry.
Biomass thermochemical conversion is complex and requires a good understanding of the thermal decomposition process. This process may be identified using mass loss kinetics which are useful for the design of proper equipment used for biomass conversion.
This work aims to determine devolatilization kinetic parameters characterizing four Tunisian biomass species: industrial by product (Pine Sawdust), agro‐industrial by product (Olive Solid Waste), agricultural residue (Date Palm Trunk) and seaweed (Posidonia Oceanica) using data from non‐isothermal thermogravimetry and the Coats and Redfern calculation method.
Decomposition TG and DTG data were analyzed by applying 10 kinetic models including processes governed by nuclei growth, surface nucleation followed by geometric, diffusion and chemical reaction models. Obtained results show that biomass pyrolysis is represented by two successive steps: (i) devolatilization stage characterized by high weight loss rate, which is well described by diffusional, surface nucleation followed by geometric and first order chemical reaction models. (ii) char formation stage characterized by low weight loss rate, which is well described by second order and third order chemical reaction models. © 2014 American Institute of Chemical Engineers Environ Prog, 33: 1452–1458, 2014
The objective of the present work was to investigate the feasability of producing activated carbons from agricultural waste corn cobs. Process parameters such as impregnation ratio of chemical activating agent to corn cob, pyrolyse temperature and soaking time were varied to examine the effects on the preparation of activated carbons by chemical activation with zinc chloride (ZnCl 2 ). The physical characterization of the resulting activated carbons was then analyzed in terms of BET surface area, total pore volume and pore size distribution.
The utilization of exhausted grape marc and vinasse, two polluting wastes from alcohol distilleries that process grape marc, is proposed. A mixture of these materials with wheat straw, in various ratios, was submitted to wet treatments with 7–15% NaOH on total dry matter at 70°C. By means of these treatments a double result was obtained: an increase in the digestibility of the two solid components and utilization of the valuable compounds contained in vinasse (which is a liquid containing about 5% d.m.).By limiting NaOH to 10% on total d.m., a final dried product with about 45% in-vitro digestibility and less than 20% crude fibre was obtained, which could probably be utilized as a feedstuff for ruminants.Further studies and larger-scale experimentation will be necessary in order to evaluate the economic suitability of the whole process.