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Torrefaction is a thermal procedure used to convert biomass into a substance resembling coal that possesses superior fuel properties compared to the original biomass. Torrefied biomass is hydrophobic and has a greater energy density, making it more advantageous for handling and storage. The purpose of this investigation is to establish a simulation model of the torrefaction process utilizing Malaysian biomass and optimize it for mass yield and energy consumption. Additionally, the objective is to integrate the optimized torrefaction process into an existing biomass power plant. By retrofitting a biomass‐based power generation facility with torrefaction technology, the existing feedstock can be upgraded before sending it to the power plant. Essentially, torrefaction technology represents an enhancement of biomass utilization technology, ultimately allowing for the maximum application of biomass energy. [ABSTRACT FROM AUTHOR]

As a thermochemical conversion process, biomass pyrolysis has received a lot of interest for energy recovery by generating clean fuels, valuable compounds, and advanced materials. Innovative and novel pyrolysis procedures have arisen over time, and these processes may be optimized to produce high-quality end products. Substantial progress has been achieved in the development of analytical pyrolysis systems during the last few decades. However, due to a lack of knowledge of the reaction process, the current mechanism of biomass pyrolysis, as well as its economic feasibility, is far from a complete and thorough explanation. This review systematically covers biomass pyrolysis for energy recovery, the most recent advances in biomass pyrolysis, and the numerous factors responsible for the end products. Furthermore, the various feedstock compositions, as well as the techno-economic analyses, have also been reported. This review emphasizes discernment into future paths, intending to overcome existing deficiencies. This review may also be employed to get new insights into this field and be useful for future studies on biomass pyrolysis. [ABSTRACT FROM AUTHOR]

This review provides the recent advances in triglyceride catalytic pyrolysis using heterogeneous dolomite catalysts for upgrading biofuel quality. The production of high-quality renewable biofuels through catalytic cracking pyrolysis has gained significant attention due to their high hydrocarbon and volatile matter content. Unlike conventional applications that require high operational costs, long process times, hazardous material pollution, and enormous energy demand, catalytic cracking pyrolysis has overcome these challenges. The use of CaO, MgO, and activated dolomite catalysts has greatly improved the yield and quality of biofuel, reducing the acid value of bio-oil. Modifications of the activated dolomite surface through bifunctional acid–base properties also positively influenced bio-oil production and quality. Dolomite catalysts have been found to be effective in catalyzing the pyrolysis of triglycerides, which are a major component of vegetable oils and animal fats, to produce biofuels. Recent advances in the field include the use of modified dolomite catalysts to improve the activity and selectivity of the catalytic pyrolysis process. Moreover, there is also research enhancement of the synthesis and modification of dolomite catalysts in improving the performance of biofuel yield conversion. Interestingly, this synergy contribution has significantly improved the physicochemical properties of the catalysts such as the structure, surface area, porosity, stability, and bifunctional acid–base properties, which contribute to the catalytic reaction's performance. [ABSTRACT FROM AUTHOR]

Torrefaction is a thermochemical process, where biomass is obtained in temperature range from from 200 to 300 °C, in inert atmosphere with the aim to increase carbon content of biomass. In this paper, emphasis is on biomass feedstock types, different effects on torrefaction success, and torrefaction reactors. [ABSTRACT FROM AUTHOR]

Co‐firing residual lignocellulosic biomass with fossil fuels is often used to reduce greenhouse gas (GHG) emissions, especially in processes like cement production where fuel costs are critical and residual biomass can be obtained at a low cost. Since plants remove CO2 from the atmosphere, CO2 emissions from biomass combustion are often assumed to have zero global warming potential (GWPbCO2= 0) and do not contribute to climate forcing. However, diverting residual biomass to energy use has recently been shown to increase the atmospheric CO2 load when compared to business‐as‐usual (BAU) practices, resulting in GWPbCO2 values between 0 and 1. A detailed process model for a natural gas‐fired cement plant producing 4200 megagrams of clinker per day was used to calculate the material and energy flows, as well as the lifecycle emissions associated with cement production without and with diverted biomass (supplying 50% of precalciner energy demand) from forestry and landfill sources. Biomass co‐firing reduced natural gas demand in the precalciner of the cement plant by 39% relative to the reference scenario (100% natural gas), but the total demands for thermal, electrical, and diesel (transportation) energy increased by at least 14%. Assuming GWPbCO2 values of zero for biomass combustion, cement's lifecycle GHG intensity changed from the reference (natural gas only) plant by −40, −23, and − 89 kg CO2/Mg clinker for diverted biomass from slash burning, forest floor and landfill biomass, respectively. However, using the calculated GWPbCO2 values for diverted biomass from these same fuel sources, the lifecycle GHG intensities changes were −37, +20 and +28 kg CO2/Mg clinker, respectively. The switch from decreasing to increasing cement plant GHG emissions (i.e., forest floor or landfill feedstocks scenarios) highlights the importance of calculating and using the GWPbCO2 factor when quantifying lifecycle GHG impacts associated with diverting residual biomass to bioenergy use. [ABSTRACT FROM AUTHOR]

The debate on the future of fossil fuels regained momentum in the late 1990s and has subsisted due to their negative environmental impact and the need to develop sustainable energy sources. Owing to the increasing emissions footprint, there is growing pressure to adapt to alternative clean energies in a bid to mitigate the deteriorating climatic conditions. Research on alternative energy sources is top on the agenda. As such, biofuels are now being tested as the next aviation fuel that has since attracted substantial attention. Various researchers have overtime sought to redefine the trajectory of research on biofuels starting from the feedstock varieties, evolving from sugar-rich crops to lignocellulosic or non-food-plant, to microalgae and to synthetic biological and metabolic engineering of fungal hosts. Substantial effort is directed at enhancing the biofuel storage capacity as well as deploying technologies that seek to enhance cost efficiency, towards ultimately making biofuels cost effective and commercialize-able. Despite the great potential of biofuels, the Sub- Saharan Africa contribution is still low, notwithstanding the cross cutting deterioration in climatic conditions. Therefore, following a systematic literature review approach, this study sought to ascertain the status of research on the commercialization of biofuels, conceptualization and the applied antecedents, as well as recommend policy actions and areas for further research. The findings suggest that commercialization is presently conceptualized on a few dimensions; capacity development towards large scale production and cost efficiency. Also, significant effort has been directed at migrating production from crop based feedstock to non-crop feedstock, as well as improving the storage life span of biofuels. [ABSTRACT FROM AUTHOR]

A detailed review was conducted to explore waste cooking oil (WCO) as feedstock for biodiesel. The manuscript highlights the impact on health while using used cooking oil and the scope for revenue generation from WCO. Up to a 20% blend with diesel results in less pollutants, and it does not demand more modifications to the engine. Also, this reduces the country's import bill. Furthermore, it suggests the scope for alternate sustainable income among rural farmers through a circular economy. Various collection strategies are discussed, a SWOC (strength, weakness, opportunity, and challenges) analysis is presented to aid in understanding different countries' policies regarding the collection of WCO, and a more suitable method for conversion is pronounced. A techno-economic analysis is presented to explore the viability of producing 1 litre of biodiesel. The cost of 1 litre of WCO-based biodiesel is compared with costs Iran and Pakistan, and it is noticed that the difference among them is less than 1%. Life cycle assessment (LCA) is mandatory to reveal the impact of WCO biodiesel on socio-economic and environmental concerns. Including exergy analysis will provide comprehensive information about the production and justification of WCO as a biodiesel. [ABSTRACT FROM AUTHOR]

The unsustainable management of sewage sludge induces environmental and economic issues, yet sewage sludge is a promising feedstock for the production of biofuels by pyrolysis. Actual challenges include poor chemical stability, high water content, high viscosity, high concentrations of nitrogen, and the presence of oxygen in the produced biofuels. Moreover the produced biochars contain elevated amounts of toxic metals and, as a consequence, may not be used in agricultural soils. Here we review the co-pyrolysis of sewage sludge with other materials to enhance bio-oil quality. Several studies show that co-pyrolysis of sewage sludge with non-biomass materials reduces water, oxygen and nitrogen contents, activation energy, and enthalpy; and increases the calorific value. [ABSTRACT FROM AUTHOR]

Global energy security relies on fossil-based resources that are affiliated with the source of global warming, apart from punches of political and economic instabilities. Biomass is a promising alternative carbonaceous feedstock used for the production of clean energy that could have the potential to substitute for fossil fuels. This study aims to present a conceptual design that considers the criteria to identify the upper theoretical limits of biomass conversion, thus providing the potential approach to the conversion of three biomass (by-products: dry molasses, dry bagasse, and dry filter cake) through gasification, in order to contribute the biomass carbon-capturing by the model assessment of stoichiometric mass conversion and energy efficiency indicators into simple thermodynamic energy vectors, such as alcohols, alkanes, and syngas (a mixture of carbon monoxide and hydrogen). Modeling plays up the importance of stoichiometric efficiency of biomass conversion with the supply of oxygen and hydrogen. This realizes that the multi-product diversification of feedstock into syngas, hydrocarbons, and alcohol through integrated process schemes could have the potential to fill the energy gap and help to manage environmental load. In regard to biomass conversion results, the mass conversion and energy conversion efficiencies of dry bagasse have better conversion potential than molasses and F. cake (% mass conversion = 129 in syngas, 54.4 in alkane, and 43.4 in alcohol; % energy conversion = 94.3 in syngas and 93.3 in alkane and alcohol). [ABSTRACT FROM AUTHOR]

Plant-based biosynthesis of fuels, chemicals, and materials promotes environmental sustainability, which includes decreases in greenhouse gas emissions, water pollution, and loss of biodiversity. Advances in plant synthetic biology (synbio) should improve precision and efficacy of genetic engineering for sustainability. Applicable synbio innovations include genome editing, gene circuit design, synthetic promoter development, gene stacking technologies, and the design of environmental sensors. Moreover, recent advancements in developing spatially resolved and single-cell omics contribute to the discovery and characterization of cell-type-specific mechanisms and spatiotemporal gene regulations in distinct plant tissues for the expression of cell- and tissue-specific genes, resulting in improved bioproduction. This review highlights recent plant synbio progress and new single-cell molecular profiling towards sustainable biofuel and biomaterial production. Advances in plant synthetic biological techniques allow for the production of various bioproducts and genetic traits. Synthetic biology can enable sustainability of plant feedstock biomass while decreasing inputs. Nanobiotechnology for the delivery of synthetic materials allows for effective gene regulation and bioproduct synthesis in plant cells and organelles. Single-cell techniques will give rise to more versatile control in rationally engineered feedstock plants. [ABSTRACT FROM AUTHOR]

With the growing scarcity of traditional sources of energy and the accompanying acute environmental challenges, biofuels based on biomass are favored as the most promising alternative. As one of the core raw materials for biomass energy, research on its production methods and synthesis mechanisms is emerging. In recent years, duckweed has been used as a high-quality new biomass feedstock for its advantages, including fast biomass accumulation, high starch content, high biomass conversion efficiency, and sewage remediation. This study provides a systematic review of the growth characteristics, starch metabolism pathways, and methods to improve starch accumulation in the new energy plant, duckweed. The study also presents a prospect that might be used as a reference for the development of duckweed as a new energy-providing plant. [ABSTRACT FROM AUTHOR]

Graesiella emersonii is a commercially exploitable source of bioactive compounds and biofuels with potential applications in microalgae-based industries. Despite this, little taxonomical information is available. Therefore, proper identification and characterization are needed for the sustainable utilization of isolated microalgae. In this study, an axenically isolated unicellular green alga from the Geumgang Estuary, Korea was investigated for its morphological, molecular, and biochemical characteristics. The morphological characteristics were typical of G. emersonii. Molecular phylogenetic analysis of the 18S rDNA sequence verified that the isolate belonged to G. emersonii and was subsequently named G. emersonii GEGS21. It was isolated from brackish water, and its optimal growth temperature, salinity, and light intensity were at 28–32 °C, 0 M NaCl, and 130–160 µmol m−2 s−1, respectively. The strain thrived over a range of temperatures (5–40 °C) and withstood up to 0.5 M NaCl. The isolate was rich in omega-6 linoleic acid (C18:2 n-6, 26.3%) and palmitic acid (C16:0, 27.5%). The fuel quality properties were determined, and biodiesel from GEGS21 could be used as a biodiesel blend. Value-added carotenoids lutein (1.5 mg g−1 dry cell weight, DCW) and neoxanthin (1.2 mg g−1 DCW) were biosynthesized as accessory pigments by this microalga. The biomass of this microalga may serve as feedstock for biodiesel production as well as producing valuable ω-6 and carotenoids. [ABSTRACT FROM AUTHOR]

As a source of renewable energy, agricultural by-products after pre-processing and cleaning in post-harvest lines can be used as a feedstock for the production of pellets or briquettes. This can be achieved by determining the physicochemical properties of the by-products. Groundnut pods, maize cobs and the husks of rice, millet and sorghum were considered, and their properties were determined, which were then compared with the standard properties of pellets and briquettes to ascertain their viability as a feedstock for the pellet or briquette production. The by-products were transported from Nigeria to the Czech Republic and the research was carried out at the Department of Technological Equipment of Buildings, the Faculty of Engineering, Czech University of Life Sciences Prague. The moisture content, ash content, calorific value, nitrogen content and sulfur content were the properties considered of the by-products. Groundnut pods and maize cobs with a calorific value of 17.48 MJ·kg-1 and 16.25 MJ·kg-1, an ash content of 3.46% weight and 1.79% weight, a nitrogen content of 1.24% weight and 0.44% weight and a moisture content of 7.92 weight and 7.56% weight, respectively, were discovered to fulfill all the requirements for graded non-woody pellets A. With the exception of rice husks and millet husks, which were discovered to have high ash contents and low calorific values, all the by-products fulfilled the standard requirements for one or more grade of pellet/briquette. They can, therefore, be used as a good feedstock for pellet or briquette production. [ABSTRACT FROM AUTHOR]

Agro-industrial residues such as bagasse, pomace, municipal residues, vinasse and cheese whey are an environmental problem around the world, mainly due to the huge volumes that are generated because of the food production to satisfy the nutritional needs of the growing world population. Among the above residues, cheese whey has gained special attention because of its high production with a worldwide production of 160 million tons per year. Most of it is discarded in water bodies and land causing damage to the environment due to the high biological oxygen demand caused by its organic matter load. The environmental regulations in developing countries have motivated the development of new processes to treat transform cheese whey into added-value products such as food supplements, cattle feed and food additives. In addition, during the last decade, several processes and technologies have been developed to produce bioenergy through the biotechnological process using cheese whey as a potential feedstock. This review discusses the production of bioethanol, biohydrogen, biomethane and microbial lipid-biodiesel production using cheese whey as a potential substrate. [ABSTRACT FROM AUTHOR]

Biofuels are increasingly important renewable resources in the world's energy matrix that have challenged the scientific community as well as small and large farmers to develop alternatives to fossil fuels in order to achieve the aims of energy transition. In particular, Brazil's proven competitiveness in agribusiness together with its rich biodiversity put the country in a key position in the biofuels market. The semiarid Caatinga of northeastern Brazil, an exclusive biome rich in many oilseed species suitable for potential energy purposes, is of particular interest in this field. Nowadays, soybeans are the main feedstock used for the production of biodiesel, but, due to the increasing demand for biofuels, the search for alternative sources of oil from tropical flora with high productivity is crucial. Under this premise, this systematic review focuses on mapping Caatinga's vegetable oil crops that could be used as alternative raw materials for biofuels' production in Brazil, in addition to traditional soybeans and sugarcane. To gain more detailed insight into these matrices, their main properties, including oil content, fatty acid profile and physicochemical properties, are discussed. Moreover, an overview is provided of processes to synthesize different types of biofuels, particularly biodiesel and aviation biokerosene, including the routes employing homogeneous, enzymatic and mainly heterogeneous catalysts. Finally, future prospects and challenges for renewable biofuels and the Caatinga biome are addressed. [ABSTRACT FROM AUTHOR]

Chlorine concentrations above 1 mg kg−1 in lipid feedstocks for biofuel production can generate corrosion issues in the different refining units as well as catalyst deactivation by clogging or fouling. To reach accurate analyses by inductively coupled plasma (ICP) techniques at low concentration levels, dilution in organic solvents rises as a simpler and more straightforward sample preparation methodology than conventional sample decomposition procedures (e.g. , microwave-assisted acid digestion). However, matrix effects and the impact of the Cl chemical form on the signal must be overcome to obtain accurate results. In this work, the high temperature torch integrated sample introduction system (hTISIS) operated at 350 °C is coupled to an inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) for the determination of Cl in lipid biofuel feedstock samples diluted in xylene and these results are compared with those reported by a conventional sample introduction system. Under optimal conditions of the hTISIS-ICP-MS/MS configuration, matrix effects are efficiently overcome (recovery values ranged from 101 to 104%) as well as the effect of the Cl chemical form on the signal for 6 organochloride compounds. Thus, an external calibration approach can be set to carry out the quantification of this element in real samples. The method is successfully validated, obtaining a good agreement in the Cl concentration reported in a standard reference material (SRM NIST 1634c) and also by comparing the concentration results obtained by external calibration and standard addition approaches in two biofuel feedstock samples. The hTISIS coupled to an ICP-MS/MS system is used for the first time to overcome not only matrix effects but also the impact of the Cl chemical form in biofuel feedstock samples. This novel method, with a limit of quantification (LOQ) of 7.1 μg kg−1, give access to an accurate Cl determination in all kind of lipid feedstocks for clean fuel production. [Display omitted] • Coupling of a total sample introduction system (hTISIS) to an ICP-MS/MS. • Matrix effect mitigation in biofuel lipid feedstock samples. • Overcoming the effect of Cl chemical form on the analyte sensitivy. • Simple and accurate Cl determination by external calibration approach. [ABSTRACT FROM AUTHOR]

A comprehensive comparison is conducted to explore the conversion performance of torrefaction and hydrothermal carbonization of high-moisture microalga for producing solid biofuel with low expense and environmental impact. The results suggest that when their solid yields are close, the hydrochar has higher HHV (higher heating value) (21.10–25.39 MJ kg−1) and energy yield (72.48–92.29%) than the biochar. The graphitization degrees of the biochar and hydrochar are 1.298–3.107 and 2.193–3.049, respectively. Considering fuel grade, the biochar is in biomass and peat zones, but the hydrochar is only in the biomass zone. The biochar's elemental valence transformation and graphitization degree are better than hydrochar's. The pyrolysis and combustion characteristics of the hydrochar are better than those of the biochar when considering the thermodegradation data, leading to a lower expense and environmental impact. The results are conducive to efficiently figuring out a solution with a comparative advantage for microalgal thermochemical conversion. The hydrothermal carbonization conditions at 160 °C for 2 h are the best operation for microalgal solid biofuel production. [Display omitted] [ABSTRACT FROM AUTHOR]

Recently introduced photoperiod-sensitive (PS) biomass sorghum (Sorghum bicolor L. Moench) needs to be investigated for their yield potential under different cultivation environments with reasonable nitrogen (N) inputs. The objectives of this study were to (1) evaluate the biomass yield and feedstock quality of four sorghum hybrids with different levels of PS ranging from very PS (VPS) hybrids and to moderate PS (MPS) hybrids, and (2) determine the optimal N inputs (0~168 kg N ha−1) under four environments: combinations of both temperate (Urbana, IL) and subtropical (College Station, TX) regions during 2018 and 2019. Compared to TX, the PS sorghums in central IL showed higher yield potential and steady feedstock production with an extended day length and with less precipitation variability, especially for the VPS hybrids. The mean dry matter (DM) yields of VPS hybrids were 20.5 Mg DM ha−1 and 17.7 Mg DM ha−1 in IL and TX, respectively. The highest N use efficiency occurred at a low N rate of 56 kg N ha−1 by improving approximately 33 kg DM ha−1 per 1.0 kg N ha−1 input. Approximately 70% of the PS sorghum biomass can be utilized for biofuel production, consisting of 58-65% of the cell-wall components and 4-11% of the soluble sugar. This study demonstrated that the rainfed temperate area (e.g., IL) has a great potential for the sustainable cultivation of PS energy sorghum due to their observed high yield potential, stable production, and low N requirements. [ABSTRACT FROM AUTHOR]

Elemental analysis of (bio)fuels and their feedstock is performed for the first time through ICP-MS/MS using a high temperature torch integrated sample introduction system (hTISIS). The system has been operated in continuous sample aspiration mode at a 30 μL min−1 liquid flow rate. An oxygen additional gas stream has been used in order to avoid soot deposit formation either in the torch or the ICP-MS/MS interface. Temperature and collision/reaction gas type and flow rate were varied in order to obtain the highest signal to background ratio. Compared with a conventional sample introduction system, the hTISIS operated at 300 °C yielded lower limits of detection. This parameter was included within the 0.005 (60Ni) to 6 μg kg−1 (28Si and 66Zn) range. An in-house method validation and uncertainty estimation were performed and it was verified that 80–90% of the uncertainty corresponded to the trueness assessment (i.e., bias, sample preparation and multielemental stock solution uncertainty). For most of the elements, the expanded uncertainty took values in between 7 and 24%. The hTISIS accounted for non-spectroscopic interferences, whereas ICP-MS/MS mitigated spectroscopic ones. This allowed the implementation of an accurate quantification method based on external calibration from a set of xylene-based standards. Thus, working with the hTISIS at 300 °C it was possible to perform the analysis of 36 samples including light petroleum cuts, diesel oil, kerosene, pyrolysis oils, vegetal oils and grease. [ABSTRACT FROM AUTHOR]

Biobutanol has been identified as a promising future biofuel. However, generally the extraction and separation of biobutanol from the fermentation mixture is a costly process. Therefore, the idea of using acetone-butanol-ethanol (ABE) mixture directly as biofuel were proposed to eliminate the recovery process. ABE has been identified as a promising future biofuel. The feedstocks play an important role in the feasibility of ABE as a fuel. Lignocellulosic biomass is seen as a promising feedstock for the production of biofuels. Thus, in this review, ABE biofuel is been summarized from three aspects namely (i) selection of feedstocks, (ii) microbial selection and (iii) hydrolysis, fermentation, and purification techniques. Anaerobic fermentation together with commonly employed recovery processes are discussed in the second part of this review. This review concludes with different challenges and future research in ABE fermentation that can pave the way for future commercialization of this promising biofuel. [ABSTRACT FROM AUTHOR]

The paper reviews the history of production and application of bio-oil (pyrolysis oil), describes its differences from other types of fuel and chemical feedstock, and considers problems associated with classifying and defining bio-oil and biofuel. The basic physicochemical properties of bio-oil are described, along with a demonstration of their variation depending on the used feedstock. Finally, methods for obtaining bio-oil and modifying its properties are outlined in relation to the primary areas of bio-oil use. [ABSTRACT FROM AUTHOR]

Eichhornia crassipes (EC) is a well-known invasive weed in different aquatic ecosystems. Its effective and complete eradication remains a challenge. The plant is a heavy metal (HM) hyperaccumulator in water bodies; however, studies regarding its biomass utilisation post-phytoremediation remain limited. The abundant growth rate and biochemical composition make EC a promising lignocellulosic feedstock for biofuel production; hence could be a deterministic approach for solving the twin problems of water pollution and higher energy demand, which are the global pressing issues in today's scenario. The present study aimed at evaluating the phytoremediation potential of EC followed by proximate and biochemical analysis to investigate its suitability for biofuel production. After two weeks, the EC removed above 90% of Lead (Pb) and 60% of Cadmium (Cd) at all experimental doses. Lower doses of HMs, especially Pb, showed stimulatory effects on E. crassipes leaf biomass (ECLB). The recovered ECLB from Pb contaminated water (1 mg L-1) was further analysed for moisture (89.23±0.86%), dry matter (10.77±0.60%), ash (11.91±1.20%), organic carbon (51.56±1.08%), cellulose (21.89±0.64%), hemicellulose (26.50±1.13%), lignin (5.62±0.83%), total carbohydrate (32.00±1.58%), and protein (20.83±0.52%) content. SEM imaging of harvested ECLB confirmed compact and rigid structure. The recorded peaks in FTIR-spectra (1015.21, 1153.71, 1246.01, 1339.63, 1419.71, 1540.71, 1646.80, 1736.73, 2933.03, and 3263.72 cm-1) indicate the presence of lignocellulosic biomass. XRD peak at 21.55° confirmed the crystalline fraction of cellulose in ECLB. The results of theoretical yields of H2 and CH4 co-generation (HMG) (210.85 mLH2/g DW and 150.28 mL CH4/g DW) and Bioethanol (0.278 g/g DW) derived from cellulose and hemicellulose content of ECLB were comparable to those in reported studies. Overall, this work demonstrates an integrated methodology of phytoremediation followed by biofuel production from the recovered phytobiomass. [ABSTRACT FROM AUTHOR]

Regional‐scale estimations of sorghum biomass production allow identification of optimum genotype×environment×management (G×E×M) combinations for bioenergy generation. The objective of this study was to determine the degree of contributions of G, E, and M toward variability in sorghum biomass in the United States. Using the Agricultural Production Systems sIMulator in a grid computing platform, biomass was simulated for irrigated and rainfed conditions for 30 years across the United States for four sorghum varietal types (grain—GS, sudangrass—SS, photosensitive—PS, and photo‐insensitive—PI). Simulated biomass was assessed by environments clustered using the sum of intercepted solar radiation (ir), mean of temperature stress factor (tp) and water stress factor (sw). Simulated biomass ranged from 5.8 t ha−1 (GS‐rainfed) to 27.5 t ha−1 (PI‐irrigated). Under high‐temperature environments (mean annual temperature = 25°C), rainfed biomass between 40 and 80 days after planting (DAP) was strongly correlated with sw (r = 0.64–0.86) and irrigated biomass with ir (r = 0.68–0.81). Under low‐temperature environments (mean annual temperature = 18°C) after 40 DAP, tp and ir had greater effects than sw (r = 0.55–0.82). Biomass variance was mainly explained by varietal type (50%–76%) in all environments×irrigation combinations, except in the high‐ and mid‐temperature environments under rainfed conditions where rainfall had the major effect (25%–45%). However, when mean temperature during the growing season decreased from 25°C (high environments) to 18°C (low environments), the contribution of mean temperature to biomass variance increased from 7% to 34% (rainfed) and from 4% to 36% (irrigated). Varietal type had the larger interactions with other factors independently of the environment and irrigation. We demonstrated a need to quantify (i) the main G×E×M drivers of biomass variability based on environmental stress factors and (ii) the variance contribution of these drivers on sorghum biomass. Our regional‐scale estimations are key inputs for future robust biomass projections of energy sorghum genotypes integrating G×E×M under climate change scenarios. [ABSTRACT FROM AUTHOR]

Biofuel expansion may entail elaborate contractual relationships between processors and farmers. Past studies have been limited to explaining choices between single contracts or standard land fixed rental versus crop share contracts. Little is known about how changes in contract attributes affect the probability of farmers' switching between contracts, if given the choice. Contract choice in turn, has implications for biofuel market structure and farmer welfare. Sugarcane expansion into the Brazilian Cerrado provides an optimal setting to investigate farmers' willingness to enter into contractual arrangements with biofuel processors. The study design involves a hypothetical stated choice experiment conducted with farmers and landowners in the Cerrado. Respondents choose between three contract types (land rental, agricultural partnership, and supply) or to opt-out. A novel two-opt opt model was applied to better model the opt out decision. Data is analyzed using a random parameter mixed logit model. Willingness to pay for contract attributes highlight farmer preference for shorter contracts with higher revenues. Direct and cross-attribute elasticities results provide unique insight into how market competition and farmer welfare can be affected by the substitution between contract options. They show a larger probability of substitution from more autonomous (e.g. supply) to less autonomous (e.g. land rental) contracts. Farmer contract preferences can motivate vertical integration in the emerging biofuel market, potentially resulting in consequences for farmer welfare and long-run sustainability of biofuel production. Our findings provide guidance for countries seeking to expand biofuel production in areas with enrooted agricultural production systems. •Biofuel expansion is boosted by greater mill presence and cane contract options. •Contract flexibility and options increase farmer willingness to grow feedstocks. •Increased market competition increases biofuel feedstock production by farmers. •Farmers prefer greater returns and lower risk over service provisions. •Farmer preference for less autonomous contracts promotes vertical integration. [ABSTRACT FROM AUTHOR]

With the continuous increase of global population, energy and hunger are the critical crisis that humankind facing in this century. Microalgae has been proposed as the solution due to the presence of the various metabolite and their attractive features. This review summaries the potential of microalgae as the feedstock for biofuel and food production. The literature indicated that the abundance of suitable fatty acid in microalgae can be used for biodiesel production while other bio-components such as carbohydrate can be used for biogas and bioethanol production. Apart from biofuel production, presence of high-quality protein, fatty acid, polysaccharides, vitamin, minerals and other bio-components with benefit biological properties in microalgae spur it as dedicated candidates for food production. However, the microalgae derived biofuel and food are still not available at the moment. The challenges that might need to be confront prior to industrial production are also briefly discussed in this review. [ABSTRACT FROM AUTHOR]

The utilization of renewable fuel alternatives holds promise for reducing the financial burden of regulatory compliance and the social responsibility associated with greenhouse gas emissions. Hydrothermal liquefaction (HTL) is one of the most versatile technologies for converting renewable biomass feedstocks (especially in the wet state) into biofuel (biocrude oil) in a compact plant. Therefore, this review is devoted to thoroughly reviewing and critically discussing biocrude oil production from biomass feedstocks through the HTL process. This review starts by discussing the principles of biomass HTL processing and product upgrading, aiming to provide a grounded and broad understanding of current developments in this domain. The data reported in the published literature are analyzed and visualized in order to scrutinize the effects of the main process parameters on the quantity, quality, cost, and environmental impacts of resultant biofuels. Higher biocrude oil yields are obtained at temperatures, pressures, and residual times between 300 and 350 °C, 24–27 MPa, and 15–25 min, respectively. Concerning yield and calorific value, biocrude oil derived from homogeneous catalysts demonstrates figures of 23.6 % and 32.1 MJ/kg, whereas that from heterogeneous catalysts exhibits percentages of 66.8 % and 40 MJ/kg, respectively. The challenges and prospects for the future development of biocrude oil are also discussed. HTL has a long way to go before being used for biofuel production on a large scale. Future studies appear to be directed towards the use of HTL technology under the biorefinery framework to maximize the exploitation of biomass into value-added products, while minimizing waste generation. [Display omitted] • Biocrude oil production from biomass by hydrothermal liquefaction is reviewed. • The principles of hydrothermal liquefaction and biocrude oil upgrading are discussed. • The effects of the main parameters on various aspects of biocrude oil are investigated. • The higher biocrude oil yields are obtained at 300–350 °C, 24–27 MPa, and 15–25 min. • Environmental and economic aspects of biocrude oil production are thoroughly discussed. [ABSTRACT FROM AUTHOR]

Modifying lignin content and composition of cell walls are key targets for bioenergy feedstock improvement for a range of renewable chemical applications. Sorghum (Sorghum bicolor) is a drought-tolerant C4 grass being developed as a dedicated bioenergy feedstock. The monolignol biosynthetic pathway produces the hydroxycinnamic subunits of lignin, a major target to increase the energy content of sorghum biomass for thermal bioenergy conversion processes. SbMyb60 is a transcription factor linked to the activation of the monolignol biosynthetic pathway and caffeoyl CoA O-methyltransferase (SbCCoAOMT) is a S-adenosyl methionine (SAM)–dependent O-methyltransferase responsible for the methylation of caffeoyl-CoA to generate feruloyl-CoA in this pathway. Overexpression of each gene resulted in increased energy content of biomass and increased levels of several aromatic compounds in previous greenhouse experiments. To assess how SbMyb60 and SbCCoAOMT overexpression lines performed under field conditions, these lines were planted in field trials over two growing seasons, 2017 and 2018, and the effects on lignin composition and content as well as agronomic traits were assessed. Field-grown plants of SbMyb60 and SbCCoAOMT overexpression lines had increased total energy and phenolic compounds. Furthermore, two SbMyb60 transgenic events, SbMyb-10a and SbMyb-15a, with decreased stover yield and seed set were combined with three sorghum lines, N32, N4692, and Tx3118, to investigate whether yield reduction could be rescued. Hybrids improved yield of SbMyb60-15a; however, hybrids were unable to improve performance for SbMyb60-10a. Overall, these results demonstrated that field-grown sorghum overexpressing SbMyb60 or SbCCoAOMT can have biomass with increased phenolic compounds and total energy. [ABSTRACT FROM AUTHOR]

Biogas and biohydrogen are compatible gaseous biofuels that can be blended with natural gas for reticulated fuel supply to reduce greenhouse gas emissions. Sustainably grown woody biomass is emerging as a potential feedstock in the production of biofuels. Woody biomass is widely available, uses non-arable land for plantation, does not require synthetic fertilisers to grow and acts as a carbon sink. The cellulose and hemicellulose fractions of wood are renewable sources of sugars that can be used for fermentative production of gaseous biofuels. However, widespread use of wood as a gaseous biofuel feedstock is constrained due to the recalcitrant nature of wood to enzymatic hydrolysis. Pretreatment makes cellulose and hemicellulose accessible to microbial enzymes to produce fermentable sugars. Here we review wood composition, its structure and different pretreatment techniques in the context of their effects on deconstruction of wood to improve hydrolysis and fermentative gaseous fuel production. The anaerobic digestion of pretreated wood for biogas and dark fermentation for biohydrogen production are discussed with reference to gas yields. Key advancements in lab-scale research are described for pretreatments and for pure, co- and mixed culture fermentations. Limitations to yield improvements are identified and future perspectives and prospects of gaseous biofuel production from woody biomass are discussed, with reference to new developments in engineered biocatalysts and process integration. [ABSTRACT FROM AUTHOR]

Sugar‐based feedstock of banana crop residues (pseudostem, peel, and rejected fruits) were integrated into first‐generation sugarcane ethanol production through simulated proposals using Aspen Hysys®. Different contents of sugars (6.5, 10, 15, 20, and 22 wt%) in the concentrated broth from banana residues were evaluated. The increase in sugar content in the broth led to an increase of 25% in the energy requirement of the evaporation stage. However, there was a reduction up to 55.31% in the energy requirement of the ethanol recovery stage with 22 wt% of sugar content. Addition of residue broth of 6.5, 10 and 15 wt% until the sugarcane broth is diluted by 20 wt% led to an increase in fermentation volume of 14.3, 19.2 and 39.7%, and an increase in ethanol productivity of 4.1, 7.9 and 26.1%, respectively. The integration of banana crop residues for a scaled‐up process showed technical viability, producing 21.97 ton h–1 of ethanol 99.50 wt%, although energy requirements of biomass pretreatment steps are still a limiting factor for the industry. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Co-gasification of coal with biomass is a novel way to utilize biomass energy and is a new research focus in clean coal technology. A thorough knowledge of the flow properties of biomass and coal binary mixtures is critical for proper processing of feedstocks to solve annoying flow problems which frequently occur in the equipment. In this paper, the flow properties (angle of repose, packing properties, and gravity discharge rate) of different biomass materials and pulverized coal binary powder mixtures were analyzed experimentally with a powder comprehensive characteristic tester and a gravity discharge experimental facility. The effects of the mixture ratio on the flow properties of different binary powder mixtures were investigated. Results indicate that the effects of the mixture ratio on the angle of repose for mixtures with different biomass species are different. For different biomass species, the bulk densities and tapped densities of their mixtures with coal decrease with increased mixture ratio. In the range of 0 ∼ 50% biomass mass content, as the mixture ratio increases, the discharge rates of different mixtures first increase, then decrease. When the biomass mass content is larger than 50%, arching phenomenon can be observed near the hopper outlet. A modified prediction model was proposed for the discharge rates of mixtures, with an error range from −45% to +25%. [ABSTRACT FROM AUTHOR]

The southern Great Plains of the USA has great potential to produce biofuel feedstock while minimizing the dual stresses of woody plant encroachment and climate change. Switchgrass (Panicum virgatum) cultivation, woody biomass captured during removal of the encroaching eastern redcedar (Juniperus virginiana) to restore grasslands and thinning of the native oak forest can provide an integrated source of feedstock and improve ecosystem services. In north‐central Oklahoma, we quantified productivity and ecosystem water use of switchgrass stands and degraded ecosystems encroached by eastern redcedar and compared these to native oak forest and tallgrass prairie ecosystems. We measured aboveground net primary productivity (ANPP) using allometric equations (trees) and clip plots (herbaceous), and evapotranspiration (ET) using a water balance approach from gauged watersheds, and calculated water use efficiency (WUE = ANPP/ET) from 2016 to 2019. Among vegetation cover types, ANPP averaged 5.1, 5.4, 6.0, and 7.8 Mg ha−1 year−1 for the prairie, oak, eastern redcedar, and switchgrass watersheds and was significantly greater for switchgrass in 2018 and 2019 (2 and 3 years post establishment) when it reached 8.6 Mg ha−1 year−1. Averaged across 2017–2019, ET was significantly greater in the forested watersheds than the grassland watersheds (1022 mm year−1 for eastern redcedar, 1025 mm year−1 for oak, 874 mm year−1 for prairie, and 828 mm year−1 for switchgrass). The mean WUE was significantly greater (9.47 kg ha−1 mm−1) for switchgrass than for the prairie, eastern redcedar, and oak cover types (6.03, 6.02, and 5.31 kg ha−1 mm−1). Switchgrass offered benefits of greater ANPP, less ET, and greater WUE. Our findings indicate that an integrated biofuel feedstock system that includes converting eastern redcedar encroached areas to switchgrass and thinning the oak forest can increase productivity, increase runoff to streams, and improve ecosystem services. [ABSTRACT FROM AUTHOR]

Abstract: Expanding the use of biofuels is controversial because of concerns about competition with food. Here we describe how varying the biofuel demand could help address these concerns. Variable biofuel demand can be implemented through market or policy mechanisms that adjust biofuel production according to feedstock availability, expanding or contracting in response to supply surplus or limitations. Based on a survey, an expert workshop, and relevant literature, the effects of a variable biofuel demand approach are evaluated with respect to food security, agricultural productivity, detrimental land‐use change, and feedstock competition with biobased chemicals and materials. Here we provide evidence that variable biofuel demand can enhance the synergistic development of agriculture, renewable biomass feedstocks and biofuels, but implementation faces several challenges. Recommendations are provided for governance options to tackle these challenges. © 2020 The Authors. Biofuels, Bioproducts, and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

On-farm feedstocks such as grass silage and cattle slurry present recalcitrant characteristics that can limit microbial conversion in biofuel production. Introducing a biochar supplement in two-stage anaerobic digestion may facilitate feedstock hydrolysis and improve energy yields in biohydrogen and biomethane production. The biomethane potentials were first investigated in batch trials without biochar supplement; results indicated a biomethane yield of 230 L per kilogram (kg) volatile solid (VS) in single-stage digestion and 275 L/kg VS in two-stage digestion. In continuous trials, operated at an organic loading rate of 4.0 g VS/L/d, the second-stage digester in two-stage digestion showed a methane yield of 237 L/kg VS with 10 g/L biochar addition; this was 7% higher than the second-stage digester without biochar addition. At the same loading rate of 4.0 g VS/L/d, the biomethane yield in continuous single-stage digestion with 10 g/L biochar addition was 212 L/kg VS; this was 3% higher than the single-stage digester without biochar addition. Biochar was found to enhance the hydrolysis of recalcitrant solid components in the hydrogen-producing phase, promote biomethane production in methanogenesis, and stabilize the digestion process. The highest energy yield of 8.5 MJ hydrogen and methane per kg VS was achieved in the two-stage digestion with 10 g/L biochar addition at a loading rate of 4.0 g VS/L/d. The results demonstrated that the application of a biochar supplement could effectively enhance gaseous biofuel production in two-stage anaerobic digestion. [Display omitted] • Co-digestion of silage and cattle slurry was compared in single and two stage. • Biochar enhanced hydrolysis and acidification in continuous two-stage process. • 10 g/L biochar enhanced CH 4 production and stabilized continuous digestion process. • Two-stage digestion increased H 2 and CH 4 production as compared to single stage. • The highest energy yield was 8.5 MJ/kg VS at 4.0 g VS/L/d in second-stage digestion. [ABSTRACT FROM AUTHOR]

A biorefinery purchasing feedstock (perennial grass) must offer contracts that provide the same opportunity to earn a profit for a feedstock contractor located 50 or 5 km from the biorefinery. The business plan presented here specifies that the biomass is purchased in satellite storage locations (SSLs), and the load-out and hauling costs are paid by the biorefinery. Contracts can be offered for harvest in September, October, and November, a three-month harvest window, or the harvest window can be extended to December, January, and February, a six-month harvest window. Required total storage capacity is 75% of annual consumption for the three-month window and 50% for the six-month window, a significant difference in total storage capacity (cost). The storage cost difference paid by the biorefinery is 5.27 and 3.52 USD/Mg for the three-month and six-month, respectively. Several issues must be addressed in the feedstock contracts: (1) earlier harvest, before plant senescence, means less nutrients are translocated back into the soil and more are removed at harvest; (2) harvest losses are higher for all harvests after the September harvest; and (3) storage losses increase with storage time in the SSL. Time of removal from the SSL is dictated by the biorefinery; thus, the feedstock contractor must be compensated. The contracts paid by the biorefinery, averaged across the entire annual consumption, were about the same for the three-month window, and six-month window. This result was obtained because fertilizer cost decreases and harvest losses increase as the harvest date increases; thus, the two factors tend to offset. Using a 77 USD/Mg base cost, representative feedstock payment at the SSL (no storage losses included) for contractors with various month contracts are September (84.30), October (85.54), November (86.72), December 88.63), January (89.98), and February (90.58). Subsequent compensation for storage losses depends on the amount of time the particular unit of biomass is in storage before shipment. [ABSTRACT FROM AUTHOR]

Life cycle assessment (LCA) was combined with primary data from nine forest harvesting operations in New York, Maine, Massachusetts, and Vermont, from 2013 to 2019 where forest biomass (FB) for bioenergy was one of several products. The objective was to conduct a data‐driven study of greenhouse gas emissions associated with FB feedstock harvesting operations in the Northeast United States. Deterministic and stochastic LCA models were built to simulate the current FB bioenergy feedstock supply chain in the Northeast US with a cradle‐to‐gate scope (forest harvest through roadside loading) and a functional unit of 1.0 Mg of green FB feedstock at a 50% moisture content. Baseline LCA, sensitivity analysis, and uncertainty analyses were conducted for three different FB feedstock types—dirty chips, clean chips, and grindings—enabling an empirically driven investigation of differences between feedstock types, individual harvesting process contributions, and literature comparisons. The baseline LCA average impacts were lower for grindings (4.57 kg CO2eq/Mg) and dirty chips (7.16 kg CO2eq/Mg) than for clean chips (23.99 kg CO2eq/Mg) under economic allocation, but impacts were of similar magnitude under mass allocation, ranging from 24.42 to 27.89 kg CO2eq/Mg. Uncertainty analysis showed a wider range of probable results under mass allocation compared to economic allocation. Sensitivity analysis revealed the impact of variations in the production masses and total economic values of primary products of forest harvests on the LCA results due to allocation of supply chain emissions. The high variability in fuel use between logging contractors also had a distinct influence on LCA results. The results of this study can aid decision‐makers in energy policy and guide emissions reductions efforts while informing future LCAs that expand the system boundary to regional FB energy pathways, including electricity generation, transportation fuels, pellets for heat, and combined heat and power. [ABSTRACT FROM AUTHOR]

This paper presents a design for a feedstock logistics system to supply a bioenergy plant located in the Southeast USA, specifically Piedmont, a physiographic region covering part of five states (VA, NC, SC, GA, and AL). The design uses a perennial grass (switchgrass) as the feedstock. Harvest is done with a round baler, and round bales are stored in single-layer ambient storage in satellite storage locations. New technology, 20-bale racks, was designed as the multi-bale handling unit. The analysis shows how proper design of the interactions between the several unit operations in a "logistics chain" can be used to minimize average delivered cost for the feedstock required for 24/7 operation. Racks are loaded at the satellite storage and delivered by hauling contractors hired by the plant and controlled by a "Feedstock Manager" at the plant to insure approximately the same number of loads are received each day. Single-bale handling at the plant is eliminated, thus the truck unload time is reduced and truck productivity (tons/day) is increased. At-plant handling and storage in 20-bale racks increases plant receiving facility productivity, and gives a reduction in plant cost to supply a continuous steam of material for 24/7 operation. [ABSTRACT FROM AUTHOR]

In light of increasing algal genomics data and knowledge of biosynthetic pathways responsible for biofuel production, an integrated resource for easy access to all information is essential to improve our understanding of algal lipid metabolism. Against this backdrop, dEMBF v2.0, a significantly updated and improved version of our database of microalgae lipid biosynthetic enzymes for biofuel production, has been developed. dEMBF v2.0 now contains a comprehensive annotation of 2018 sequences encoding 35 enzymes, an increase of over 7-fold as compared with the first version. Other improved features include an increase in species coverage to 32 algal genomes, analysis of additional metabolic pathways, expanded annotation thoroughly detailing sequence and structural features, including enzyme–ligand interactions, and integration of supporting experimental evidence to demonstrate the role of enzymes in increasing lipid content. Along with a complete redesign of the interface, the updated database provides several inbuilt tools and user-friendly functionalities for more interactive and dynamic visualization of data. [ABSTRACT FROM AUTHOR]

The utilization of polymeric biorenewables for the synthesis of biofuels and essential chemicals is largely obstructed by their recalcitrant structures and complex product distribution. Here, hydrosilane-mediated hydrodeoxygenation (HDO) of the furanic mixture 5-hydroxymethylfurfural (HMF) and 5-chloromethylfurfural (CMF), directly derived from cellulosic biomass, can be enabled by heterogeneous Pd-catalyzed dechlorination to exclusively give the biofuel 2,5-dimethylfuran (DMF) in a high overall yield of 72%. Kinetic and isotope labeling studies supported by computational calculations explicitly elucidate the reaction pathways. The initial dechlorination of CMF into acidic species promotes the rapid in situ formation of relatively stable acetalized and etherified furanic intermediates, which not only greatly accelerate the reactivity of the entire HDO process (TOF: up to 1200 h−1), but are also able to significantly get rid of unwanted side reactions. Importantly, this catalytic system can also be applied for the upgrade of various chlorinated carboxides to produce ortho-, meta- and para-substituted arenes with satisfactory yields of 82–99% at 25–45 °C, and the used commercial Pd/C catalyst is highly recyclable. [ABSTRACT FROM AUTHOR]

The yield of standard annual cuttings from the mother poplar plantation remains high enough for the 15th year in such clones as 'Ijzer-5', 'Robusta', 'Tardif de Champagne', and 'San Giorgio'. Clones 'Ghoy' and 'Dorskamp' showed a high level of survival (47 and 80%, respectively) after planting in phytomeliorated mix of loess-like loam and red brown clay in the Dnipropetrovsk province. The differences in the thermal characteristics of the samples of tested cultivars reflected in changes in the composition of extracted substances caused both genetic, climatic, and soil conditions. [ABSTRACT FROM AUTHOR]

Tomato pomace, a solid by-product of tomato processing industries, was assessed for the first time as a feedstock for acetone-butanol-ethanol-isopropanol (ABEI) fermentation. After the pretreatment with hydrothermal process and enzymatic hydrolysis of tomato pomace with a 20% solid-to-solvent ratio, a broth containing 44.1 g/L total sugars was obtained (61.0% saccharification yield). Twelve Clostridium strains were compared to find an appropriate microorganism for the transformation of tomato pomace hydrolysate. Four of these strains produced 0.22–5.95 g/L acetone, 5.82–7.00 g/L butanol, 0.17–0.39 g/L ethanol, 0.05–8.28 g/L isopropanol and 11.03–15.07 g/L ABEI. The strain C. beijerinckii DSM 6423 obtained 2.67 g butanol, 2.99 g isopropanol and 5.92 g ABEI from 100 g dry tomato pomace (containing 30.6 g carbohydrates). In addition, another pretreatment was performed with a 30% solid-to-solvent ratio in order to obtain higher sugar concentrations, obtaining a hydrolysate with 85.1 g/L total sugars (66.8% saccharification efficiency), which was employed for bioethanol production by comparing twelve different yeast and bacterial strains. Kluyveromyces marxianus DSM 5422, Saccharomyces cerevisiae Ethanol Red®, S. cerevisiae Hércules and Lachancea thermotolerans DSM 3434 produced 20.1–21.7 g/L ethanol (about 5.21 g ethanol per 100 g dry tomato pomace). According to these results, tomato pomace could be an interesting feedstock for ABEI biorefineries. [ABSTRACT FROM AUTHOR]

This paper investigates the thermochemical characteristics of date palm fronds (DPFs) to use as feedstock for different energy conversion processes. The proximate analysis, ultimate analysis, calorific value measurements, and elemental content measurements were carried out using some quantitative and qualitative techniques. At later stage, the gasification of DPFs was carried out in an externally hot gasifier system. The effect of gasification temperature and biomass particle size on gas composition and heating value of producer gas was investigated. The results showed that the thermochemical characteristics of DPFs were comparable with other biomass materials reported in the past literature. The gasification trials of the biomass revealed that temperature has a significant effect on gas composition, especially H2 and CO contents. The high temperature yielded high H2 and CO concentrations in the product gas. A good quality gas composition (in terms of H2, CO, CH4, and CO2 contents) was obtained from bigger particle sizes as compared to smaller sizes. The thermochemical characteristics of DPFs and gasification results showed that DPF feedstock is comparable with other conventional biomass for production of energy through appropriate thermochemical technologies. [ABSTRACT FROM AUTHOR]

• A. furnesiana is utilized as source to prepare NiFe 2 O 4 as well as a feed stock. • Maximum AFOME yield of 93.1% is obtained at optimal conditions. • Catalyst is magnetically recovered 100% y and reused up to 5th cycle. • The activation energy (Ea) and thermodynamic parameters have been analysed. • Green chemistry metrics has been studied. Magnetic nanoparticles as heterogeneous catalysts could open up new possibilities for the development of eco-friendly biodiesel production. In the present study, the Acacia furnesiana (A. furnesiana) fruit component namely pods and seeds are successfully employed as low-cost and environmentally-safe starting materials for the synthesis of NiFe 2 O 4 NPs and also as feedstock for biodiesel synthesis respectively. Interestingly, A. furnesiana seed extract is utilized for the first time as a feed stock for the biodiesel production using NiFe 2 O 4 NPs as catalyst. Using response surface methodology and linear regression, the optimum conditions for the biodiesel production using NiFe 2 O 4 catalyst is obtained. An excellent A. furnesiana oil methyl ester (AFOME)/biodiesel yield of 93.1% is achieved with 4.61 wt% of NiFe 2 O 4 loading, 14:1 M ratio of methanol to oil, 53 min reaction time and at a temperature of 65 °C. The NiFe 2 O 4 catalyst after transesterification reaction is recovered 100% using a permanent magnet and can be reused up to four cycles with > 80% AFOME yield at the end of 4th cycle. The activation energy for AFOME production is found to be ∼ 44.54 kJ/mol from kinetic study and, the thermodynamic investigation revealed that the enthalpy and entropy of the system is ∼ 27.49 kJ/mol and −0.18 kJ mol/k, respectively. [ABSTRACT FROM AUTHOR]

Abstract Factors affecting flocculating properties of two oleaginous yeasts, Candida tropicalis X37 and Yarrowia lipolytica TISTR 5151 were evaluated in order to simplify harvesting process and increase process productivity. Among these two yeasts, Y. lipolytica TISTR 5151 showed high flocculation efficiency (>95%) at acidic pH while C. tropicalis X37 gradually flocculated independently to pH. Both yeasts and their mixed culture grew well and accumulated high lipid content (>30%) in palm oil mill effluent added with crude glycerol at 1–2%. Interestingly, the mixed culture enhanced lipid productivity and COD removal possibly due to stabilization of pH and efficient organic carbon consumption. Y. lipolytica TISTR 5151 with appropriate inoculum size could also be used as bioflocculent for other yeasts. The fatty acid composition of yeast lipids and their prospect fuel properties indicate their potential use as biodiesel feedstocks. Graphical abstract Image Highlights • A new approach for lipid production by flocculent yeasts was attempted. • Yarrowia lipolytica TISTR 5151 showed high flocculation (>95%) at acidic pH. • The flocculent yeasts have high potential to convert industrial wastes into lipids. • The mixed culture of flocculent yeasts enhanced lipid production and COD removal. [ABSTRACT FROM AUTHOR]

Abstract The effective pre-treatment methods are required for the destruction of the complex biomass structure to economically produce high grade fuels and valuable platform chemicals. Ionic liquids have high potential for energy efficient biomass pre-treatment due to their low vapour pressure, emission profile, recyclability and tuneable properties; some ionic liquids can even be prepared from renewable biomass feedstocks. However, a number of issues currently impede the large scale uptake of ionic liquids including their cost of production, detailed understanding the macro, micro and molecular level deconstruction mechanisms which inhibits process optimisation and modelling, and the need for techno-economic astable sessment on large scale trials. So far, laboratory to bench scale IL pre-treatments of various lignocellulosic biomasses were studied by changing various process parameters where the aims were to investigate the biomass dissolution mechanism and understand the pre-treatment performance of ILs. This review outlines current research gaps and potential applications for ionic liquids in the destruction of biomass into its components followed by separation of lignin, hemicellulose and cellulose rich fractions. Graphical abstract fx1 Highlights • Laboratory to bench scale biomass pre-treatment processes are discussed. • Progresses on the modelling of process optimisation are presented. • Issues with scale-up of ionic liquid pre-treatment processes are detailed. • Integration of hydrolysis process with ionic liquid pre-treatment is examined. • Challenges in the developed processes and future research directions are discussed. [ABSTRACT FROM AUTHOR]

Global energy consumption is expected to grow by 56% between 2010 and 2040. Renewable energy is one of the fastest-growing energy resources, and biomass is a major feedstock for providing renewable energy. It constitutes up to 35% of the main energy consumption in developing countries. Densified solid biofuel with high density gets a lot of attention due to its uniform shape and low heating cost. When considering densified solid biofuels as a viable solution for energy production, its quality needs to be improved. Solid biofuel quality is a function of the chemical composition and physical properties of the raw materials. It is widely reported that the raw material chemical composition has a major effect on the final solid biofuel quality, as it influences the heating value, ash content, and mechanical durability. The moisture content influences the net heating value, combustion efficiency, and mechanical durability of solid biofuels. The bulk density influences the mechanical durability, thermal characteristics, as well as handling and storage costs of solid biofuels. This work reviewed the latest developments on the effects of the chemical composition, moisture content, and bulk density of raw materials on the thermal efficiency, emission, and mechanical durability of densified solid biofuels. [ABSTRACT FROM AUTHOR]

The yields in bioconversion of residues produced in the Cameroon food industry to liquid and gaseous biofuels were evaluated and the potential of these residues as feedstock for renewable energy production in Cameroon were assessed. Residues generated after processing avocado, cocoa, and peanut crops were converted at laboratory-scale to second-generation gaseous biofuels (biogas) and liquid biofuels (ethanol). Mechanical (milling), thermal-chemical (steam-NaOH), and microwave pretreatments were applied before hydrolysis of biomass using cellulolytic enzymes. Cellulosic sugars production potential was also assessed. The energy conversion rate was higher when anaerobic digestion technology was applied to convert the tested biomass to methane. The total Cameroon potential under anaerobic digestion technology is over 330,000 m3, which represents 28% from oil consumption or 5.39% from electricity consumption when lignocellulosic ethanol technology was applied. The national potential was assessed up to 200,000 kg, representing 17% from oil consumption in transport or 3.19% from electricity consumption. Overall, the share of energy potential of the tested residual biomass is important when compared to fossil fuel consumption in Cameroon and represents an important potential feedstock for electricity production. [ABSTRACT FROM AUTHOR]