Search

Biofuel covers major parts of the transportation sector in the global economic scenarios. Therefore, the impact assessment parameters like environmental, economic, and social are necessary to evaluate for better understanding. Keeping in mind, a life cycle assessment of biodiesel has been done using Jatropha curcas as feedstock. All the steps from cradle (cultivations, pre-treatment, and transesterification) to gate (biodiesel production) have been evaluated. The functional unit of one ton of biodiesel has been taken as reference, and environmental impacts are assessed accordingly using SimaPro. In the current paper, the conventional and room temperature process for biodiesel production is compared in terms of mid-point categories like greenhouse gas (GHG) emission and other endpoint categories like human health, ecosystems, and resources. The results from the life cycle assessment (LCA) indicates that the room temperature process is more energy-saving than the conventional process. Room temperature biodiesel produced around 1195 kg CO2 eq of emission contributing to global warming, whereas the conventional biodiesel contributed around 1228 kg CO2 eq to GHG emission. Further, the Monte Carlo analysis was carried out to quantify the uncertainty in the process in terms of normalized global warming potential. The biodiesel production from the room temperature process can be explored at the industrial level in future. [ABSTRACT FROM AUTHOR]

Cow dung is generally used as the feedstock material for the anaerobic digestion to produce biogas. A selection of alternate biomass material is needed to reduce the consumption or to eliminate the use of cow dung. Recently, cottonseed hull has been considered as the primary substrate to produce biogas. In this paper, the effect of biogas production on anaerobic co-digestion of CD with pre-treated CSH using sulfuric acid, hydrochloric acid, hydrogen per oxide, and acetic acid is investigated. The concentration of each acid has been varied as 1%, 2%, and 3%. In addition, the two alkaline, namely, sodium hydroxide and calcium hydroxide, are used at different concentrations of 4%, 6%, and 8%. The biogas yield obtained from the mono-digestion of pre-treated CSH and the co-digestion of CD with chemically treated CSH at the ratio of 75:25 (CD: CSH) using the experimental results are compared. The enhancement of biogas production from the batch reactors at mesophilic temperature where the cow dung is mono- and co-digested with acid-treated and alkaline-treated cotton seed hull are observed and compared. The maximum biogas yield is achieved for the treated CSH at the concentration of 6% NaOH that offers 13-fold improvement over untreated CSH during mono-digestion. Whereas in co-digestion, it achieved a 6-fold improvement over untreated CSH with the ratio of 75:25 at the concentration of 6% Ca(OH)2. [ABSTRACT FROM AUTHOR]

Lignin is an aromatic compound found as a major component of plant cell wall and therefore, present abundantly in nature as a renewable resource. Due to its organic nature, it has the potential to serve as feedstock for value addition to sustainable bioproducts. Under biorefinery concept, each of the plant biomass components viz. cellulose, hemicellulose, and lignin must be converted to some or the other products. Thus, development of different strategies to valorize lignin for chemicals other value-added products can remove the economic constraint on bioethanol-based biorefineries. However, lignin is highly heterogenous than its counterparts and therefore, very recalcitrant to bioconversion making its biovalorization very difficult. To fully utilize the potential of lignin, it is necessary to understand its degradation process and develop efficient biochemical/microbial strategies to achieve cost-effective lignin bioconversion. In recent times, many innovations have taken place in sustainable microbial utilization and bioconversion of lignin. Therefore, this paper focuses on the progress made in lignin biotransformation's for production of bio-based products, chemicals, and bioenergy in the context of biorefinery concept, with a critical perspective on biotechnological advancements, challenges, and future needs. [ABSTRACT FROM AUTHOR]

With the rise in global population, industrialization, and economic expansion, the persistent overconsumption of conventional fossil fuels has resulted in the depletion of fossil fuel reserves. This has fuelled the need to investigate and boost scientific research efforts on sustainable and renewable bioenergy feedstock. A substitute that can minimize reliance on nonrenewable energy resources while also lowering greenhouse gas emissions. In this context, biofuels have received a great deal of interest in recent years as a prospective substitute for conventional fossil fuels. The prime reason behind this is the feedstock utilized in their synthesis. The feedstocks employed here are environmentally safe, nontoxic, and emit little to no pollution. These feedstocks are classified into four generations: first, second, third, and fourth. Food crops and lignocellulosic biomass and waste constitute first- and second-generation feedstocks. The third- and fourth-generation feedstock is microalgae. This paper provides a comprehensive overview of feedstocks utilized to produce biofuels, including the various pre-treatment methods, strategies, and techno-economic analysis in order to pave the way for next-generation biofuels. It also covers the advantages, drawbacks, challenges, and current developments. [ABSTRACT FROM AUTHOR]

In this paper, pulsed light (red light, 625 nm) with different parameters were set to study the response of cyanobacterial photosynthetic rate to pulse frequency, intensity, and duty ratio by using the oxygen electrode, in order to achieve optimized light mode for high-efficiency cultivation of microalgae. The results showed that pulsed light with high frequency and small-duty ratio could alleviate photoinhibition under high light stress and achieve similar even higher photosynthetic rate compared to continuous light with the same peak intensity. Photosynthetic rate of cyanobacteria under the same intensity and duty ratio rose with the increase of frequency and reached a relatively stable high level when the frequency went above 100 Hz. Interestingly, under the condition of 2100-µmol photon m−2 s−1 peak intensity, 33% duty ratio, and 200 Hz, the photosynthetic rate was 1.13 times that under continuous light (2100 µmol photon m−2 s−1), saving nearly 67% of the input light energy and improving the conversion rate of light energy by 3.4 times. Mechanisms of pulsed light effect are also analyzed, based on the consumption and accumulation of intermediate substance. The conclusion of this study plays a positive role in reducing the operating cost of algal cultivation by the photobioreactor and even provides a new idea in the microalgal growth under outdoor stress conditions. [ABSTRACT FROM AUTHOR]

Hydrothermal liquefaction (HTL) is an evolving technology that can convert waste with high moisture and low energy content to electricity, heat, hydrogen and other synthetic fuels more efficiently. The lee side is that the HTL process produces enormous amounts of wastewaters (HTWW), having high organic and nutrient load. The discharge of the HTWW would contaminate the environment and result in the loss of valuable bioenergy sources. The valorisation of HTWW has drawn considerable interest. Therefore, this review highlights the valorisation of wastewater during the HTL of biomass. The review paper begins with the discussion of the role of microalgae in valorizing the HTWW. The survey illustrates that the selection of appropriate technology is dependent on biomass characteristics of the microalgae. Finally, potential research opportunities are recommended to improve the viability of the HTL wastewater valorisation for bioenergy production. Overall, this review concludes that combining various processes, such as microalgae-anaerobic digestion, and bio-electrochemical system - microalgae-anaerobic digestion would be beneficial in maximizing HTWW valorisation. [ABSTRACT FROM AUTHOR]

Bioethanol is expected to have a major contribution to transportation fuel consumption; hence, environmental analyses are crucial tools to evaluate its environmental performances. In this paper, a life cycle assessment is carried out to study the environmental performance of a bioethanol production system from Tunisian waste dates. The life cycle foreground data were derived from process simulation, while the background data were provided by the Ecoinvent 3.3 database. The impact assessment method applied is the ReCiPe midpoint (H). Seven environmental impact categories are discussed in detail in the interpretation section: global warming, acidification, eutrophication, agricultural land occupation, water depletion, cumulative energy, and cumulative exergy demands. The results indicate that 1 MJ of bioethanol produced from waste dates generates approximately 0.07 kg CO2-eq, which appears comparable with second-generation bioethanol production. One MJ of bioethanol requires approximately 1.087 MJ-eq of primary energy consumption of which 1.065 MJ is nonrenewable. The electric power generation process is the main contributor to most of the environmental impact categories (process hot spot). Therefore, it is strongly recommended to rely on renewable electricity generation to ensure relevant environmental improvements. [ABSTRACT FROM AUTHOR]

CaO and phosphates showed synergistic effects in the regulation of pyrolysis products in the pyrolysis of when they were directly mixed with camphor wood. The alkyl phenol yield increased during the pyrolysis process of corn straw fermentation residue directly mixed with KH2PO4 supported by γ-Al2O3. Rice stalks from agricultural crops are often disposed as waste. However, the potassium phosphate impregnated raw straw pyrolysis with CaO and Al2O3 has not been reported. This paper studied the synergistic effects of CaO or Al2O3 and three potassium phosphates (i.e., KH2PO4, K2HPO4·3H2O, and K3PO4·3H2O) in the rice straw pyrolysis through pyrolysis–gas chromatography-mass spectrometer (Py-GC/MS) experiments. The results showed that CaO/Al2O3 and potassium phosphates showed synergistic effects in the regulation of the types or contents of phenols, ketones, aldehydes, etc. and increased the contents of phenols, aldehydes, acids, and levoglucosan (LG) from most samples and increased those of ketones compared with those catalyzed by potassium phosphates alone. They were suitable for the production of ketone-rich and acid-low bio-oil, which is an important precursor for the preparation of power or jet fuel. The highest contents of ketones (HCK) reached 56.65% and 56.02% in the pyrolysis of K3PO4·3H2O impregnated rice straw with CaO or Al2O3, respectively. The lowest contents of acids and acetic acid (LCA) were nearly or equal to 0, respectively. HCK and LCA were respectively significantly higher and lower than the values reported in the literatures for biomass catalytic pyrolysis using CaO/Al2O3 and potassium phosphates alone or in combination. Dehydration reactions, etc. were further promoted under the co-catalysis of the two catalysts, and some phenols could be converted to benzene products, etc. For 50% K3PO4·3H2O impregnated sample, the yields of furans reduced sharply after CaO addition. For most impregnated samples except 50% K2HPO4·3H2O and 30% and 50% K3PO4·3H2O samples, the contents of total furans and furfural increased after Al2O3 addition. Highlights: CaO/Al2O3 and potassium phosphates showed synergistic effects in the regulation of the types or contents of phenols, ketones, aldehydes, etc. They were suitable for the production of ketone-rich and acid-low bio-oil, which was an important precursor for the preparation of power or jet fuel. Dehydration reactions, etc. were further promoted under the co-catalysis of the two catalysts, and some phenols could be converted to benzene products, etc. The lowest contents of acids and acetic acid were nearly or equal to 0, respectively. [ABSTRACT FROM AUTHOR]

This paper introduces a methodological framework for assessing the sustainability of solid biofuels in Mexico. The designed framework comprises 13 normalized indicators and two diagnostic studies, covering the economic, social, environmental, and institutional sustainability dimensions, and their intersections. Indicators are normalized using the concept of load capacity of a system, similarly to the planetary boundaries. Thus, the graphical representation of results facilitates their multidimensional analysis. The framework was applied to three case studies: traditional fuelwood in rural households, charcoal for restaurant grilling, and electricity cogeneration from sugarcane bagasse. This was part of an iterative process of testing and refining the framework and simultaneously demonstrating its application in the Mexican bioenergy context. This led to the conclusion that the resulting framework (a) provides a useful, quantitative, and comprehensive overview of both broad and specific sustainability aspects of the assessed system; (b) requires a balance of accessible but also scattered or sensitive data, similarly to most existing frameworks; (c) is highly flexible and applicable to both modern and traditional solid biofuels; and (d) is simple to communicate and interpret for a wide audience. Key directions for improvement of the framework are also discussed. [ABSTRACT FROM AUTHOR]

Biomass represents 10% of the total energy use and 55% of all renewable energy in Mexico. It is a key energy source to help Mexico achieve a low-carbon development path to comply with the strict climate mitigation targets needed to avoid catastrophic consequences. However, a major limitation in the construction of reliable future mitigation scenarios is the lack of information regarding in-country greenhouse emission factors associated to both traditional and modern bioenergy devices. This paper aims to close this gap, providing detailed estimates of energy and emission factors from bioenergy devices in the Mexican residential and industrial sectors. In particular, four energy tasks, comprising 67% of current bioenergy use in the country, were selected (charcoal production, biomass drying, space heating, and cooking) with a total of nine bioenergy devices: traditional earth mound charcoal kiln, flash dryer, heater, five types of cookstoves, and an open fire. The thermal efficiency ranged from 10 ± 1 to 26 ± 5% for the cooking devices, 95 ± 1 to 96 ± 1% for the space heater, 34 ± 8% for the charcoal kiln, and 10 ± 2% for the biomass dryer. The modified combustion efficiency was calculated to be 88 ± 1% for the earth mound charcoal kiln, 96–98% for the cookstove, and 93–98% for the space heater. The products of incomplete combustion ranged from 21 ± 6 to 48 ± 12 g for the cooking devices and 58 ± 18 to 340 ± 107 g for the space heaters. CO2 emission factors ranged from 102 ± 2 to 119 ± 2 g/MJ for the local biomass stoves. Relative to other pollutants, the CO emissions per energy unit were the highest, ranging from 1193 ± 184 mg/MJ for the space heater to 18,121 ± 1232 mg/MJ for the earth mound charcoal kiln. The total global warming potential was estimated to be 35 ± 2 gCO2e/MJ for the ONIL stove (modified) and 158 ± 4 gCO2e/MJ for the earth mound charcoal kiln. The estimates presented in this study represent an important contribution to Mexico's inventories in terms of energy performance and emissions parameters of four energy tasks in the industrial and residential sectors. This information will be a baseline to estimate carbon footprint, life cycle assessments, GHG emissions scenarios, and mitigation strategies for local and regional Mexican conditions. [ABSTRACT FROM AUTHOR]

In this paper, the regions where Cynara cardunculus L. is cultivated in Turkey are revealed, with data obtained from several locations in Turkey. Furthermore, the installation of active biogas plants in these regions has been identified, and the utilization of Cynara cardunculus L. residues as a biomass source, particularly in Izmir biogas plants, has been investigated. To begin, the amount of Cynara cardunculus L. cultivated in the world and Turkey has been determined. According to the Food and Agriculture Organization of the United Nations (FAO)'s recent data for 2019, approximately 1.6 million tons of Cynara cardunculus L. were produced globally, with Turkey accounting for nearly 2.5% of this quantity. The data from the Biomass Energy Potential Map for Turkey (BEPA) was reviewed, and it was calculated that approximately 40 thousand tons of Cynara cardunculus L. are produced in Turkey each year. Furthermore, the agricultural production of this crop in Turkey generates roughly 225 thousand tons of residues. In comparison to other regions, the Izmir region generates 32.5% of Turkey's Cynara cardunculus L. residues. However, no research on the evaluation of this residue potential and the utilization of Cynara cardunculus L. residues in biogas production has been conducted to date. As a result, it was aimed at the residual potential of Cynara cardunculus L. in various regions of Turkey, as well as its potential utilization as a biomass resource for biogas plants in these areas. It has been calculated that 1.65% of the Izmir population could supply its energy demands by utilizing the energy equivalent of the Izmir region's wastes. [ABSTRACT FROM AUTHOR]

Biomass is considered an important source of energy, in particular wood and forestry waste are one of the major sources of biomass energy in some places for residential use. However, little information is given for industrial use. This paper evaluates the environmental life cycle of the combustion of forestry waste for the generation of heat that is used in a sawmill. The sawmill produces plywood and timber in the state of Durango, Mexico, and produces forestry waste that needs to be valorized into energy. Hence, its environmental impact assessment was compared when fuel oil is used for energy generation. The results of the life cycle assessment suggest that the heat generated by the combustion of biomass is environmentally more attractive, obtaining a negative mitigation of − 107.8% in the category of eutrophication potential, when is compared with fuel oil. Thus, considering the indexes of each of the categories, the potential environmental index (PEI) was 0.064 when forestry waste is used in contrast with 0.156 PEI/MJ for fuel oil. It is concluded that the waste obtained in the forestry industry can be used for heat generation and thus contributes to the energy required for the forestry industry, with less environmental impacts than fuel oil. [ABSTRACT FROM AUTHOR]

Life cycle assessments conducted in the last decade on forest-derived solid biofuels contain key insights to assess the environmental impact of such fuels under different contexts. This paper reports on the results of a systematic review of 87 studies that applied life cycles assessment on five types of solid biofuels: firewood, charcoal, wood chips, briquettes, and pellets. By considering the particularities of the countries in which the studies were conducted, biomass sources, end-uses and life cycle methodological choices, and key insights were derived about the global distribution of studies and what existing works can contribute to general understanding of the sustainability of wood-based fuels. First, most life cycles assessment focus on modern solid biofuels in developed countries, only 13% were on traditional solid biofuels such as firewood and charcoal in developing countries. Secondly, there are remarkable inconsistencies across studies in how they report and define their system boundaries. Thirdly, global warming potential is the most widely applied impact category. A meta-analysis of a subset of the studies (N = 26) revealed that, in general, forest-derived solid biofuels have lower global warming potential than fossil-based alternatives. Given the global imbalance of life cycle assessment efforts on forest-derived solid biofuels, there is need to mobilize capacities in order to increase applications in developing nations. However, persistent low uptake of standardized application and reporting in life cycle assessment studies perpetuates oft-mentioned limitations for cross-study comparisons. An approach to standardize system boundaries is proposed to partially address these limitations. [ABSTRACT FROM AUTHOR]

In Mexico, the possibility to exploit orange peels or sugarcane straw to generate heat has not been fully explored, even though they are major agronomic wastes generated in Mexico. Therefore, this paper aims to assess the heat generation's environmental and economic performance from these feedstocks in a fruit-processing facility located in Veracruz, Mexico. The environmental performance was assessed through the life-cycle assessment methodology, while the economic performance was estimated through the total levelized cost of energy (TLCE) considering two scenarios: (1) a base scenario where orange peels are burnt to produce process steam, and (2) a second scenario where sugarcane straw is co-fired with it. Both scenarios assume to partially displace heavy-fuel–oil (HFO) for steam generation. Results indicate that the impacts of the use of residual biomass-based heat on the potential global warming, ozone layer depletion, marine aquatic ecotoxicity, and cumulative energy demand are 34–63% lower than when using HFO and decrease the TLCE by 18–21%. However, there is also an increase in other environmental impact categories such as human toxicity, photochemical oxidation, or eutrophication. The use of orange from organic farms improves the environmental results in some of these categories. The drying and combustion of the biomass, as well as the waste treatment, are the major contributors to the environmental impacts. On the other hand, capital and fuel costs are the major contributors to TLCE. Overall, the use of orange peels and sugarcane straw to generate heat is attractive from the environmental and economic point of views. [ABSTRACT FROM AUTHOR]

Combination of chemical treatment by cosolvent with hydrodynamic cavitation is a novel technique of intensification of alkali-catalyzed transesterification of sunflower oil with methanol. The paper investigated the effect of operating parameters such as reaction mixture inlet pressure (p1), methanol to oil molar ratio (M1), the concentration of catalyst (Cc), methanol to tetrahydrofuran (THF) molar ratio (M2), temperature (T), and a number of passes through the hydrodynamic cavitation reactor (n) of transesterification of sunflower oil in the presence of the cosolvent assisted by hydrodynamic cavitation (ACTC) on the triglyceride conversion (TC). ACTC was performed by a venturi-type cavitation reactor (VCR) of a given design. The effect of the operational parameters on the TC was investigated by the method of independent variation of the value of one operating parameter. The obtained results indicated that (a) at p1 ≥ 304.0 kPa TC increased from TC = 0 to TC = 98% following the rise in p1; (b) maximum TC = 95% was achieved at M1 = 3; (c) rise in M1 within range 3 ≤ M1 ≤ 9 led to a linear increase from TC = 95 to TC = 100%; (d) maximum TC = 95% was achieved at 1.0%wt ≤ Cc ≥ 1.1%wt; (e) maximum TC = 99% was achieved at M2 = 1.5; (f) TC linearly decreased from TC = 95 to TC = 88% with T rise from T = 20 to T = 55 °C; (g) the rise in n resulted in a linear increase of TC from TC = 94 (n = 1) to TC = 99% (n = 10); and (h) cavitation yield (CY) declines from CY = 0.528 (n = 1) to CY = 0.056 g/J (n = 10). [ABSTRACT FROM AUTHOR]

High demand for crop oils is anticipated in the lubricant industry because of their renewable, non-toxic, environment-friendly nature. Crop oils typically offer high viscosities, viscosity indexes, and flashpoints. The unique structure of crop oils provides good lubrication, high flammability, and anti-corrosion ability. In contrast, petroleum-based lubricants face a difficult future because of declining petroleum reservoirs that will increase their prices. This paper reviews green-lubricant feedstock requirements, the effect of fatty acids composition to improve physicochemical properties, chemical modifications of green lubricants by applying transesterification to find suitable environmentally -friendly and cheaper feedstock to replace petroleum lubricants. Moreover, global and Pakistani indigenous crop oils are also analyzed for their potential use in green lubricants by comparing their fatty acid compositions, characteristics and reaction conditions according to applications and standards. This review discovers that cottonseed oil has great potential as a new sustainable and cheaper feedstock for the global and Pakistani green-lubricant markets. Green lubricant production rate can be enhanced significantly after upgrading the conventional production method. It is believed that this review paper will provide useful information to engineers, researchers, chemists, industrialists, and policymakers, who are interested in green-lubricants synthesis. [ABSTRACT FROM AUTHOR]

The use of Posidonia oceanica (PO) waste biomass for energy production is under consideration in several countries of the Mediterranean region. The aim of this paper is an evaluation of using PO waste as a biomass source for direct combustion in territorial contexts where the presence of large quantities of beached seagrass is a problem for the tourism-orientated economy such as Istrian peninsula in Croatia. The presence of large PO leaves deposits on the Istrian beaches is responsible for some negative inconveniences, such as the odor released during the natural degradation processes. Other problems are connected with the visible appearance of the beach and negative connotation of PO with pollution of the touristic area. This condition reduces the possibility of touristic competitiveness of the hotels, apartments, bars, and restaurants that are located along the seaside promenade or beaches covered with PO biomass. This paper shows data of PO waste properties as a resource for energy generation which can help to decrease costs of their collection and could improve the quality of life of residents and tourists in the nearby areas. From energy properties, the heating values of fresh and dried onshore biomass samples of PO biomass were within the range of main agricultural and forest biomass and it was around 9–11 MJ/kg; ash content is very high (16–36%) compared with other types of biomass. Due to the abovementioned data, PO waste carries some inherent limitations to its use as biomass in direct combustion and energy generation, primarily due to high ash content. Furthermore, PO waste can be recognized as a potential fuel for combustion or co-combustion due to its low sulphur (1.15–2.36%) and nitrogen (1.47–2.39%) content but the low carbon content (25–32%) is not a favorable characteristic. It can be concluded that PO waste is a potentially interesting source for energy production. [ABSTRACT FROM AUTHOR]

Alkali combined with ozone pretreatment of corn straw could improve the enzymatic hydrolysis degree of cellulose to realize the biomass conversion of straw waste. In order to recycle the alkali black liquor derived from this process and realize the environment-friendly effect, the main components of alkali combined with ozone pretreatment of straw recycling black liquor were investigated in this paper. To this end, the alkali black liquor was sequentially withdrawn for 0–6 times under the optimal pretreatment conditions, and solid content, organic and inorganic matter, acid precipitation, alkali precipitation, and organic composition were analyzed to identify the main factors inhibiting cellulase hydrolysis in recycled alkali black liquor. The results showed that the cellulase hydrolysis rate presented a significant decrease at the fourth cycle, which was decreased by 11.39%, and the content of alkali precipitation was maximum (0.707 g). Meanwhile, the organic matter content in alkali precipitation also reached the maximum value of 0.491 g. Through the component analysis, the contents of lignin and acid precipitation increased throughout the cycles. Moreover, GC–MS results showed that phenols, benzene ring heterocyclic, and furans were main degradation products in cycles of black liquor. Accordingly, it was indicated that small molecular organics and lignin were inhibitors of cellulase hydrolysis, which accumulated during recycling, and reduced alkali utilization and delignification efficiency, resulting in lower enzymatic hydrolysis rate. [ABSTRACT FROM AUTHOR]

Pennisetum hydridum has several beneficial characteristics, including the ability to grow quickly, a highly developed root system, the ability to produce high yields, strong resistance to environmental stressors, and the ability to adapt to different growth environments. Recent studies have shown that Pennisetum hydridum has the potential to play an important role in the sectors of bioenergy, environmental remediation, and livestock fodder. The objective of this paper is to review the current research on Pennisetum hydridum in China and discuss its potential for phytoremediation, biofuel development, and feed utilization. Pennisetum hydridum is resistant to a variety of stressors and can adapt to different growth environments. It can be used for the remediation of heavy metal-contaminated land, restoration of saline-alkali land, and nutrient removal of constructed wetlands, as well as soil and water conservation. Pennisetum hydridum exhibits a higher biomass yield, caloric value, and cellulose content than other bioenergy crops, suggesting it has superior potential as a second-generation biofuel resource. As a type of forage grass, Pennisetum hydridum also has an appealing taste and high feeding value, in addition to its high nutrition value. A comprehensive utilization framework for Pennisetum hydridum has been proposed in order to promote high-efficiency utilization of this multipurpose crop and fully realize its maximum potential. Research on Pennisetum hydridum as a bioenergy resource, however, is still in its infancy. Additional work is needed to better understand its breeding and genetic transformation processes, its energy conversion mechanism, and the biological pathways that support its growth and adaptability, so that this valuable resource may be utilized in the most productive way possible. [ABSTRACT FROM AUTHOR]

Renewable energy contributes to the energy portfolios of many countries. One form of renewable energy is syngas which is generated from bio-residues. The focus of this paper is the biomass transportation and conversion network that covers the entire syngas (synthesis gas) production process from different biomass feedstocks to the end products. Specifically, we focus on the resource planning and management problem (a) to allocate different feedstocks to anaerobic digesters (reactors), (b) to determine number and locations of reactors in each region, (c) to determine number and locations of the condensers to liquefy syngas, and finally (d) to determine distribution network of syngas to demand points. We developed a mixed-integer, non-linear programming (MINLP) cost model to describe this resource planning wherein the constrained cost is minimized to find the optimal solutions for reactors and condensers locations. We identify optimal allocation of feedstocks to all reactors and the distribution of liquefied gas to distribution centers. We propose a new algorithm to search for an alternative between two sub-problems of the original MINLP. We verify the convergence of the algorithm to an optimal or sub-optimal solution by conducting various sets of numerical experiments using some real-world parameters. [ABSTRACT FROM AUTHOR]

The production of biomass from legumes for energy purposes is considered an important element of sustainable agriculture. Leguminous plants allow the biological fixation of nitrogen (BFN), which contributes to reduction in the input of mineral fertilizers, and hence lightens the environmental burden. Replacing mineral inputs into crop production using BFN (the production of silage) represents an important step towards achieving greater sustainability of biogas station operation. This paper deals with the possibility of using silage prepared from a mixture of conventional energy crops—corn and legume (lupine) in biogas stations. The aim of the paper was to find out how the addition of legume affects the production of methane and to determine the optimal ratio of maize and lupine in silage. Different variants of silage were prepared: without the addition of legume (sole corn), with the addition of lupine at different ratios (50/50, 70/30, 90/10), and sole lupine. This silage was subjected to fermentation tests and analyzed in order to determine the nutrient content effect on the fermentation process. The lowest total methane production was detected in the lupine silage and the highest total methane production was observed in the maize silage (0.327 m3 CH4/kg VS) and in the mixed silage 90/10 (0.330 m3 CH4/kg of VS). It was found that with the increasing proportion of lupine in the silage, methane production (50/50 < 70/30 < 90/10) declines due to the increased content of poorly degradable organic substances. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass is one of the most abundant raw materials in the world, and it is mainly composed of carbohydrate polymers (cellulose and hemicellulose) and lignin. Its applications vary from the production of pulp and paper, to the most recent plant-based bioethanol production, which has challenge due to low hydrolysis conversion rates by the inherit recalcitrance of biomass. The biomass is naturally resistant due the high complexity in the component organization and interaction in the cell wall. The application of pretreatment technologies is one of the most used strategies to overcome biomass recalcitrance. These techniques often require a catalyst to modify the lignocellulosic structure which can be acids, alkaline compounds, ionic solutions, organic solvents, and even pressurized steam among others. The type of catalyst dictates the name of the pretreatment involved. This work presents an overview of these strategies, along with some recent contributions from the scientific community to improve biomass conversion technologies. The discussion is focused on the key factors related to the recalcitrance and conversion process, as well as the composition and physicochemical properties. [ABSTRACT FROM AUTHOR]

Biomass alkaline deacetylation prior to acid pretreatment can be a promising alternative to reduce the toxicity of hemicellulosic hydrolysates and improve second-generation bioethanol production. In this paper, the effect of alkaline deacetylation of sugarcane bagasse on bioethanol production by Spathaspora passalidarum was evaluated. Sugarcane bagasse deacetylated hemicellulosic hydrolysate (DHH) was processed using the following sequence: (1) deacetylation (0.4%, w/v NaOH, 70 °C, 3 h) and (2) acid pretreatment (0.5% (v/v) of H2SO4, 140 °C, 15 min). Non-deacetylated, hemicellulosic hydrolysate (HH), was obtained applying only acid pretreatment (0.5% (v/v) of H2SO4, 140 °C, 15 min). Biomass deacetylation reduced the content of acetic acid and some phenolic compounds in the hydrolysate (DHH) compared to acid pretreatment (HH), which resulted in its low toxicity. Thus, the bioethanol production with DHH was of 16.92 g L−1, whereas only 1.3 g L−1 of bioethanol was obtained with HH fermentation. Deacetylation process provided a 13-fold increase in bioethanol production by S. passalidarum, showing that alkaline deacetylation followed by sulfuric acid pretreatment is a promising strategy to increase bioethanol production. This procedure provided a simple and practical alternative to the classic methods of detoxification of hemicellulosic hydrolysate from sugarcane bagasse. [ABSTRACT FROM AUTHOR]

With realizing the potential of algal biomass as a good natural resource for the harnessing of valuable bioproducts, algal biomass production has gained a lot of interest in recent years. However, due to some limitations such as low harvesting efficiency, higher nutrient supply, and high water requirement, the production of algal biomass is uneconomical. Over the past several years, researchers are continuously working on growing algae as a biofilm for easy microalgae harvesting, concentration of algal biomass to a great extent, and requiring less quantity of water as compared to other microalgae cultivation methods. Most of the documented studies have been carried out on either use of algal biomass for tertiary treatment of wastewater or cultivation and harvesting of algal biomass for biofuel production. Limited research studies have documented other applications of the algal biofilm system. The present review paper summarizes the current knowledge on various factors affecting microalgae growth, development of algal biofilm, and operation of algal biofilm systems to help properly understand and optimize these factors for better economics, more positive environmental impacts, and successful potential applications of the attached growth systems. The important factors include the structure of algal biofilms, EPS matrix, supporting materials, nutrient availability, environmental conditions, and biofilm thickness and harvesting frequency. The potential applications such as wastewater treatment, CO2 sequestration, microalgae–microbial fuel cell, large-scale biomass production, and water quality improvement are also discussed. [ABSTRACT FROM AUTHOR]

The saccharification of Chlorella sp. biomass by single and combined commercial carbohydrase enzymes, Termamyl SC, Dextrozyme GA, and Cellic CTec2, was investigated. A substrate concentration of 100-g volatile solids (VS)/L was optimal for all the enzymes used. The optimal enzyme dosages for Termamyl SC, Dextrozyme GA, and Cellic CTec2 were 160-units/g VS, 320-units/g VS, and 40–filter paper units/g VS, respectively. The maximum reducing sugar yield, 130-mg/g VS, was obtained with a Dextrozyme GA treatment, which is equivalent to 38.37% hydrolysis efficiency based on carbohydrate content. A combined-enzyme treatment with Cellic CTec2, Termamyl SC, and Dextrozyme GA raised the reducing sugar yield and hydrolysis efficiency to 186.69-mg/g VS and 54.85%, respectively. Scanning and transmission electron microscopic images indicated morphological alterations in Chlorella sp. cells as an effect of enzyme treatment. Enzyme treatment improved the hydrogen production, hydrogen production rate, and hydrogen yield from Chlorella sp. biomass. The maximum hydrogen yield, 42.24-mL/g VSadded, was obtained from a Dextrozyme GA–hydrolyzed microalgae biomass. This was 82.46% higher than that obtained from untreated biomass (23.15-mL H2/g VSadded). Fourier-transform infrared analysis revealed that the functional groups of Chlorella sp. biomass, especially carbohydrates, were modified by both enzymatic treatment and the hydrogen fermentation process. This work demonstrated the efficient saccharification of Chlorella sp. biomass using combined cell wall– and starch-degrading enzymes. The results also elucidate that the pretreatment of Chlorella sp. biomass by commercial glucoamylase is a promising approach to solubilize internal starch granules and promote biohydrogen production without the addition of any cell wall–degrading enzyme. [ABSTRACT FROM AUTHOR]

In this paper, biogas potential produced from animal manure has been calculated using data for various regions of Turkey between 2007 and 2019. Moreover, generation of electricity potential that can be provided using biogas obtained from animal manure resources has been examined. The animal numbers subjected to the study have been reached via the Turkish Statistical Institute. The amount of animal manure, which is the basis for calculating the amount of biogas, has been calculated using the average number of animals and the animal weight. Eastern Anatolia and Central Anatolia Regions have the highest biogas potential with 19% compared with the other regions due to amount of manure obtained from animal. The finding of this study denotes that 76,448 × 106 m3 potential of methane content can be obtained from biogas for the mentioned years, and 2,339,296 × 106 MJ potential of heating value can be obtained from this methane value. While the potential of electricity energy, which can be provided from animal manure wastes, has been 231,009 × 106 between 2007 and 2019 in Turkey, the total electricity consumption in 2007–2019 is 2,898,040 × 106 kWh. The results show that the potential electricity that can be provided from animal manure could meet 7.99% of the electricity consumed in the same years. Furthermore, the cost analysis of biogas facility, which is established in Eastern Anatolia Region, has been performed using circular economy model. According to calculations, the discounted payback period has been found to be 10 years. [ABSTRACT FROM AUTHOR]

Green diesel, also known as renewable diesel, is a biofuel obtained from biomass with similar physical properties than petroleum diesel. Renewable diesel is mainly composed by hydrocarbons free of oxygen, which can be blended at high concentrations with petroleum diesel due to their chemical affinity. Density and viscosity are two important physical properties of fuels that play an important role in the processes of atomization and injection in engines. Also, the knowledge of these properties is important for the correct design, operation, and optimization of chemical processes. Despite their importance, there is low information about experimental data and developed models related to the renewable diesel–petroleum diesel blend. To overcome the above limitation, this paper is focused on the study of four blends of renewable diesel and petroleum diesel in order to study the variation of density and kinematic viscosity with respect to the concentration and temperature. In addition, empirical correlations to predict the density and kinematic viscosity as function of temperature and concentration were developed. Density and viscosity of renewable diesel, petroleum diesel, and their blends were simultaneously measured with a densitometer–viscometer device with an uncertainty in density and viscosity of 0.1 kg/m3 and 1 × 10−8 m2/s. The parameters of the developed correlations were adjusted by the Levenberg–Marquardt optimization method. There was a good agreement between the calculated and experimental data because an average absolute deviation (AAD) of 0.07 and 1.66% were obtained for the predictions of density and kinematic viscosity respectively. [ABSTRACT FROM AUTHOR]

Five different inocula from cow manure, goat manure, pig manure, and rumen fluid (RU) and microbial sludge from anaerobic digestion were screened to select anaerobic lignocellulolytic microbial consortium (ALMC) of high efficacy in degradation of filter paper (FP), microcrystalline cellulose (MCC), and rice straw (RS) to produce methane. RU from Bubalus bubalis demonstrated the highest growth rate RU inoculum (10.45 mgVS/day); fastest degradation rate of FP, MCC, and RS (125.00, 50.07, and 25.43 mgVS/day); and highest methane production rate (6.23 ml/day). To obtain the enriched and stabilized ALMC from RU, consecutive batch subculturing was used and reached at 25 passages, namely, E25. The efficacies of E25 in RS removal and methane production were 78%VS and 293 ml/gVSadded compared with initial inoculum (E0) at 46% VS and 138 ml/gVSadded, respectively, within 14 days of incubation time. The efficacies of E25 in RS removal and methane production were 1.7- and 2.12-folds higher than of E0, respectively. E25 showed high ability to utilize various carbon sources (68%) from Biolog EcoPlate assay. It was confirmed that E25 could degrade derivatives of cellulose, hemicellulose, and lignin. Metagenomic analysis by 16 s and shotgun sequencing of E25 found dominant species of hydrolytic/fermentative bacteria (Proteiniphilum acetatigenes, Pyramidobacter piscolens, Syntrophus aciditrophicus, Mesotoga prima, and Candidatus Cloacimonas acidaminovorans) and methanogens (Methanoculleus bourgensis, Methanoculleus marisnigri, Methanofollis liminatans, Methanosarcina mazei, and Methanosaeta harundinacea). This stabilized E25 with enrichment of lignocellulolytic and fermentative bacteria as well as hydrogenotrophic and acetoclastic methanogens shows its efficacy in accelerating RS degradation and methane production. [ABSTRACT FROM AUTHOR]

In this paper, the acidic pretreatment of microalgal biomass is investigated, and the solubilized biomass and hydrolyzed sugars were evaluated. The process is analyzed through the severity factor approach (acidic combined severity factor (ACSF)). A suitable kinetic model is developed and applied, and it is shown that the severity factor theory works. A discussion and comparison are presented with respect to the literature methods, which are mainly related to lignocellulosic biomass. In the case of microalgae, reaction orders for biomass and acid are shown to be the main parameters, and no other assumptions are needed. Two regions of the acidic treatment process have to be evaluated: low and high reactivity regions. Furthermore, a suitable experimental design is required in order to provide an appropriate reaction spectrum to obtain a good estimation of the kinetic parameters. A logarithmic severity factor range (ln ACSF) between 5 and 6 is able to solubilize around 80% of biomass and to hydrolyze more than 90% of sugars present in the biomass. [ABSTRACT FROM AUTHOR]

In Europe, poplar and other fast-growing tree species are considered valuable resources for meeting the required wood demand of the rising bioeconomy. The agricultural technique of short rotation coppice (SRC) has gained relevance to ease the pressure of the demand for wood from forests. Previous studies have implemented the life cycle assessment (LCA) methodology to evaluate such systems' potential environmental impacts. These studies present different outcomes, though a general pattern on the potential benefit of SRC is observed. The variation of relevant methodological options, such as goal and scope, system boundary, functional unit, reference system, data source, characterization models, and impact categories assessed can significantly affect the results. A consequence of this discrepancy is its effect on results' interpretation, making the absolute comparison of case studies challenging and hindering the understanding of the potential impacts of SRC LCAs in support of developing a sustainable bioeconomy. Therefore, the current research attempts to understand the methodological implementation of LCA in assessing SRC value chains. Through literature research, studies are analyzed based on the four LCA phases. One of the results of this study shows how most of the articles focus on assessing the impact category related to climate change, while other environmental issues that are particularly relevant for agricultural woody biomass systems are seldomly evaluated. By discussing the state of the art of SRC LCA, this review paper attempts to suggest improvements that will allow future LCA studies to reach a more comprehensive understanding of the overall environmental impact of SRC systems. [ABSTRACT FROM AUTHOR]

This paper describes the possibility of replacing the single-fuel spark-ignition engines (SFSIE) fuelled with gasoline by the dual-fuel spark-ignition engines (DFSIE) fuelled with bioethanol and biogas. GASEQ software was used to estimate the combustion exhaust gases of the bioethanol, biogas and gasoline with 27% ethanol and 20% ethanol in order to calculate the energy-ecological efficiency of the DFSIE and the SFSIE. The tank-to-wheel (TTW) emissions were calculated to analyse the amount of carbon dioxide (CO2) emitted per kilometre and compared to the tailpipe emissions standards defined by the United States and European Union. The results showed that the energy-ecological efficiency found for the DFSIE fuelled with 50% bioethanol and 50% biogas was higher than that found for the SFSIE fuelled with gasoline. However, the TTW emissions of the DFSIE in category 2.0 presented the lowest emission values when compared to the other categories. As can be seen from the results obtained in the present study, the use of the DFSIE fuelled with bioethanol and biogas reveals the effect on the energy-ecological efficiency and the TTW emissions. The findings of this study can be used as a guide for public policy makers in order to assist their planning of sustainable urban mobility programs. [ABSTRACT FROM AUTHOR]

Based on this stability, they detected twelve QTL clusters that were established based on either biomass production or composition traits and validated by the high genetic correlations between the traits. Most of the production traits showed large interaction variances for age and climate at both locations, in contrast to biomass composition traits, which showed large interaction variances at one location only. Within the twelve QTL clusters of biomass composition traits, Raverdy et al. [[6]] identified 62 cell wall-related candidate genes with orthologs in sorghum and maize. [Extracted from the article]

There has been rapid economic development in China in recent decades, and demand for energy has consequently been increasing rapidly. Development and utilisation of clean and renewable energy has been promoted by the Chinese government to help sustain long-term and stable development. Sugarcane is being increasingly used in several countries as feedstock for renewable energy products, and is a major and expanding crop in southern China. In this paper, we discuss the potential of sugarcane as a feedstock for bioenergy production in China. It includes a review of (1) the existing sugarcane industry in China and key bio-physical factors affecting the extent to which sugarcane-based industries could supply feedstock for renewable energy production in China, (2) the economic and policy factors which are likely to affect production of bioenergy from sugarcane in China, and (3) recommendations on actions and policies that may assist with appropriate development of bioenergy production from sugarcane in China. Existing and expected future economic conditions are unlikely to favour production of biofuel from the sugar component in cane. However, the fibre component of cane remains an under-utilised resource component. A conclusion is made that sugarcane fibre has potential to contribute towards renewable electricity production in China. However, at present, favourable incentives do not exist to encourage this production. It is suggested that policies to facilitate cost-effective production of renewable electricity by sugar mills, consistent with national objectives regarding production of renewable energy, be considered by governments. Priorities for future research are in improving biomass yields per unit area of land and technologies for low-cost conversion of lignocellulosic biomass into biofuel. [ABSTRACT FROM AUTHOR]

This study adopts an integrated life-cycle approach to assess overall carbon saving related with the utilization of wood pellets manufactured using pulpwood and logging residues for electricity generation. Carbon sequestered in wood products and wood present in landfills and avoided carbon emissions due to substitution of grid electricity with the electricity generated using wood pellets are considered part of overall carbon savings. Estimated value of overall carbon saving is compared with the overall carbon saving related to the current use of pulpwood and logging residues. The unit of analysis is a hectare of slash pine ( Pinus elliottii) plantation in southern USA. All carbon flows are considered starting from forest management to the decay of wood products in landfills. Exponential decay function is used to ascertain carbon sequestered in wood products and wood present in landfills. Non-biogenic carbon emissions due to burning of wood waste at manufacturing facilities, wood pellets at a power plant, and logging residues on forestlands are also considered. Impacts of harvest age and forest management intensity on overall carbon saving are analyzed as well. The use of pulpwood for bioenergy development reduces carbon sequestered in wood products and wood present in landfills (up to 1.6 metric tons/ha) relative to a baseline when pulpwood is used for paper making and logging residues are used for manufacturing wood pellets. Avoided carbon emissions because of displacement of grid electricity from the electricity generated using wood pellets derived from pulpwood fully compensate the loss of carbon sequestered in wood products and wood present in landfills. The use of both pulpwood and logging residues for bioenergy development is beneficial from carbon perspective. Harvest age is more important in determining overall carbon saving than forest management intensity. [ABSTRACT FROM AUTHOR]

The effects of the blends of charcoal fines and Schizolobium parahyba var. amazonicum (paricá) wood on the briquette quality and on the combustibility of this solid biofuel is not fully understood, especially from fast-growing plantations with Amazonian tree species. In addition, this paper presents new information about the occurrence of inorganic elements that may contribute to increase the emission of toxic compounds in the combustion of paricá wood, for example, Cl. Thus, this study evaluated the composition of charcoal and S. parahyba var. amazonicum wood for briquettes, investigating the occurrence of inorganic elements responsible for the toxic organochlorine contaminants. Different formulations between charcoal and S. parahyba var. amazonicum wood were analyzed and later compacted in a laboratory briquetting machine with temperature of 90 °C and pressure of 5 MPa. The chemical and elemental composition of S. parahyba var. amazonicum wood was determined using X-ray fluorescence spectrometry (μ-XRF). The briquettes produced were tested for bulk and energy densities, proximate composition, heating value, equilibrium moisture, and resistance to diametral compression. S. parahyba var. amazonicum wood had chlorine levels below the recommended by international standards for solid biofuel intended for non-industrial use (< 300 mg kg−1). S. parahyba var. amazonicum, despite being a fast-growing species, has ideal chemical characteristics for energy purposes (Cl, S, and ashes). The most suitable briquettes were those produced with 50% of charcoal and 50% of S. parahyba var. amazonicum wood. This solid biofuel showed higher heating value of 22.74 MJ kg−1 and ash content of 2.65% db. [ABSTRACT FROM AUTHOR]

This paper presents an assessment of the utilization potential of biomass residues for grid-connected power generation in Thailand, including the spatial distribution and seasonal variation of biomass residues and energy potential. The levelized costs of electricity (LCOE) in various scenarios were also estimated. The residues of up to 17 studied crops were selected depending on the regions. ArcGIS was used as the tool for assessing and mapping the biomass potential. The potential of grid-connected power generation was assessed based on a biomass-fired power plant, the seasonal availability of crop residues by region, and the location of the electrical substations. Based on a 50% of collection factor (base case), the total energy potential of the available biomass residues was 11,299 ktoe year−1, which can generate 5019 MW (30,491 GWh year−1) of power and had LCOEs for power plant capacities of 5 to 9 MW in the range of US$77.72 to 87.66 MWh−1. The results also show that 17.3 MtCO2 year−1 of GHG emissions could be avoided with the abatement cost ranging from −US$89.36 to − 115.83 tCO2−1. According to Thailand's PDP2018, the estimated electricity generation potential was approximately 8.3% of forecasted electricity demand in 2037. The improvement of the collection factor by up to 75%, the power generated, and the GHG emissions avoided were about 1.5 times higher than the base case. These findings are useful for the management, promotion, and zoning of biomass utilization for power generation. [ABSTRACT FROM AUTHOR]

Several studies have highlighted the importance of the chemical composition of Eucalyptus woods in the generation of thermal energy and charcoal production. However, the influence of wood chemical constituents on the pyrolysis mass balance is still not sufficiently clear. This paper brings new insights about the influence of extractives and guaiacyl (G) to syringyl (S) ratio of lignin macromolecule in the carbon, hydrogen, and oxygen balances of the pyrolysis process. Thus, the aim of this research was to investigate the effect of the wood quality of genotypes of Eucalyptus on the carbonization mass balances. Ultimate analysis, structural chemical constituents, and lignin composition analyses were carried out in 14 clonal materials of Eucalyptus spp. at 81 months of age. After pyrolysis, the ultimate analysis of charcoal and the carbonization mass balance was also investigated. The findings show a positive relationship between the percentages of carbon and hydrogen retained in the charcoal with the lignin content and its composition. E. camaldulensis (clone 1025) and E. grandis hybrids (clone 1039) presented better wood quality for charcoal production, due to the results of gravimetric yield (35.7%), retained carbon (59.6%), and retained hydrogen (20.2%) after pyrolysis. In addition, these genetic materials stood out for the high values of lignin (32.0%), extractives soluble in acetone (2.4%), and mass of guaiacyl per kg of dry wood (27.2 g kg-1) associated with the low S/G ratio (2.5). The extractives content and lignin composition must be simultaneously analyzed to improve the Eucalyptus clones classification for charcoal production. [ABSTRACT FROM AUTHOR]

The thermal characteristics and kinetics of the microalgae Dunaliella salina were evaluated through microwave catalytic pyrolysis under composite additives (blends of graphite (GP) and Na2CO3 (NC)). GP was blended with NC of 0%, 30%, 50%, 70%, and 100%, which were named as NC, 3GP7NC, 5GP5NC, 7GP3NC, and GP. Then different amounts (5%, 10%, and 15%) of NC and 5GP5NC were also studied. The pyrolysis characteristic parameters, characteristic index (D) and activation energy (E), and thermodynamic parameters, including enthalpy (∆H) and Gibbs free energy (∆G), were studied in this paper. In all the groups with the amount of 5%, the initial decomposition temperature (Ti) decreased with the NC proportion of the composite additive increased. The 5GP5NC group obtained the largest values of maximum weight loss rate (Rmax), average weight loss rate (Rmean), and D, which were 3.78%/min, 1.67%/min, and 12.35 × 10−7, respectively. However, the NC group achieved a small value of E (66.28 kJ/mol), ∆H (60.46 kJ/mol), and ∆G (175.97 kJ/mol). When changing the amounts of 5GP5NC, the suitable amount was 15%, based on its largest D (13.76 × 10−7), smallest E (52.49 kJ/mol), excellent weight loss, and thermodynamic characteristic. For NC, the maximum Rmax was obtained at 15%, while the greatest D and minimum E were achieved at 5%. [ABSTRACT FROM AUTHOR]

The paper evaluates the relation between energy input (Ei) and output (Eo) of biogas production from six energy crops: maize, sorghum, sunflower, triticale, reed canary grass (RCG), and Virginia mallow (VM), cultivated in three different nitrogen fertilization levels. Furthermore, in the case of RCG, the impact of cutting system was examined. The results showed that raised N fertilization dose (in the range of 40–120 kg ha−1 and 80–160 kg ha−1, depending on the crops) increased biomass yield and methane productivity (MP) but simultaneously caused also the increase in Ei. Nonetheless, the application of higher N doses did not cause drastic decrease in energy use efficiency (EUE). The Ei was significantly lower for perennials than for annual crops. For this reason, EUE for RCG harvested in two cuts (5.0–5.2 GJ GJ−1) was close to EUE for maize (5.7–6.8 GJ GJ−1), despite the much lower MP (2027–2903 m3 ha−1 and 4409–5692 m3 ha−1, respectively) and Eo (73–105 GJ ha−1 and 159–205 GJ ha−1, respectively). Furthermore, the collection of RCG in more than two cuts turned out to be unjustified, due to increase in Ei and, simultaneously, decrease in MP. [ABSTRACT FROM AUTHOR]

Melons belong to the Cucurbitaceae family and are grown in the tropical and temperate regions of the world. With numerous identified varieties, melons are regarded as one of the most economically important vegetable crops. 'Egusi' melon, one of the most popular members of the melon family with diverse species, has formed a significant part of the diet of many Africans and Asians. Egusi melon seed kernels are a good source of edible oil (31–59%), protein (19–37%), fibre (3–4%), and carbohydrate (8–20%). The objectives of this review are to highlight the food uses of egusi melon and its prospect for biodiesel production. Firstly, an introduction to egusi melon is presented, describing its origins, varieties, cultivation and yield, followed by an extensive review of the nutritional composition, oil extraction methods and analysis and food uses of egusi. Then, the engineering properties of egusi fruits, seeds and kernels and the energy utilisation of its biomass are shown. This review also covers the use of egusi seed kernel oil for biodiesel production, the rheological properties of egusi biodiesel, its engine performance, emission characteristics and the conformity of the biodiesel to standard specifications. Finally, future challenges and research directions are presented. This paper will prove to be a viable resource for the food, energy and automobile industries, as well as the scientific community. [ABSTRACT FROM AUTHOR]

This research paper is about the kinetics of drying and pyrolysis processes of lulo (Solanum quitoense Lam.) peel powder, which was studied using thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and mass spectrometry (MS). TG data was fitted using theoretical approximation according to the Newton model to obtain the kinetic parameters of drying, and the isoconversional methodology using Friedman's method for the pyrolysis process. The results of each thermogram showed a relation between each other. In all of them, three characteristic stages were identified related to drying, pyrolysis, and carbonaceous matter. At the same time, there was a decomposition of the lignocellulosic biomass and light volatiles in the pyrolysis process. In the thermograms, three characteristic stages were identified: the first stage is the dehydration which ended at 120 °C, the second is the pyrolysis which is between 120 and 450 °C, and from this temperature, the third stage, carbonization, begins. In the pyrolysis stage, five peaks corresponding to independent reactions were identified; activation energy (Ea) and the reaction mechanism (f(α)) of each peak were calculated by means of master curves. After comparing the theoretical and experimental master plots, it was observed that the reaction mechanism corresponds to the Avrami-Erofeev model. Thermal analyses indicate that lulo peel is a potential waste for the production of coal for power purposes. It could be contributing to improve the management of waste and at the same time it could be used as a power supply or for water treatments such as activated carbon. [ABSTRACT FROM AUTHOR]

Cassava (Manihot esculenta) is a woody bush extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates. The main residue from its cultivation is the cassava stalk, which is normally used as soil fertilizer or in culture propagation. The main goal of this paper is to evaluate two routes (biochemical and thermochemical) for bioenergy production (ethanol and synthesis gas—electricity) using cassava stalk as raw material. A detailed techno-economic and energy assessment is carried out based on the simulation approach of both conversion routes to determine the production costs of main products and the overall energy efficiency of the processes. The electricity production costs vary from 0.008 to 0.037 USD/MJ, whereas the ethanol production costs range from 1.11 to 2.02 USD/L (including subsidies). The change in the production costs was observed due to the assumptions of the model, e.g., cassava stalk, transportation, and enzyme costs. The overall energy efficiency of the gasification and ethanol fermentation was 68.7 and 25.1%, respectively. [ABSTRACT FROM AUTHOR]