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The use of microalgae and bacteria as a strategy for the startup of bioreactors for the treatment of industrial wastewater can be a sustainable and economically viable alternative. This technology model provides satisfactory results in the nitrification and denitrification process for nitrogen removal, organic matter removal, biomass growth, sedimentation, and byproducts recovery for added-value product production. The objective of this work was to evaluate the performance of microalgae and bacteria in their symbiotic process when used in the treatment of paper pulp industry wastewater. The experiment, lasting fourteen days, utilized four bioreactors with varying concentrations in mgVSS/L of microalgae to bacteria ratio (R1-100:100, R2-100:300, R3-100:500, R4-300:100) in the startup process. Regarding the sludge volumetric index (SVI), the results show that the R1 and R2 reactors developed SVI30/SVI10 biomass in the range of 85.57 ± 7.33% and 84.72 ± 8.19%, respectively. The lipid content in the biomass of reactors R1, R2, R3 e R4 was 13%, 7%, 19%, and 22%, respectively. This high oil content at the end of the batch, may be related to the nutritional stress that the species underwent during this feeding regime. In terms of chlorophyll, the bioreactor with an initial inoculation of 100:100 showed better symbiotic growth of microalgae and bacteria, allowing exponential growth of microalgae. The total chlorophyll value for this bioreactor was 801.46 ± 196.96 μg/L. Biological removal of nitrogen from wastewater from the paper pulp industry is a challenge due to the characteristics of the effluent, but the four reactors operated in a single batch obtained good nitrogen removal. Ammonia nitrogen removal performances were 91.55 ± 9.99%, 72.13 ± 19.18%, 64.04 ± 21.34%, and 86.15 ± 30.10% in R1, R2, R3, and R4, respectively., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The proper treatment and utilization of kraft black liquor, generated from the pulp and paper industry through the kraft pulping method, is required to reduce environmental impacts prior to the final disposal. It also improves the economic performance through the utilization of waste. Microbial valorization appears to demonstrates the dual benefits of waste management and resource recovery by providing an innovative solution to convert kraft black liquor into resource for reuse. A comprehensive review on the microbial valorization of kraft black liquor, describing the role in valorization and management, is still lacking in the literature, forming the rationale of this article. Thus, the present study reviews and systematically discusses the potential of utilizing microorganisms to valorize kraft black liquor as a sustainable feedstock to develop a numerous portfolio of platform chemicals, bioenergy, and other value-added products. This work contributes to sustainability and resource efficiency within the pulp and paper industry. The recent developments in utilization of synthetic biology tools and molecular techniques, including omics approaches for engineering novel microbial strains, for enhancing kraft black liquor valorization has been presented. This review explores how the better utilization of kraft black liquor in the pulp and paper industry contributes to achieving UN Sustainable Development Goals (SDGs), particularly clean water and sanitation (SDG 6) as well as the affordable and clean energy goal (SDG 7). The current review also addresses challenges related to toxicity, impurities, low productivity, and downstream processing that serve as obstacles to the progress of developing highly efficient bioproducts. The new directions for future research efforts to fill the critical knowledge gaps are proposed. This study concludes that by implementing microbial valorization techniques, the pulp and paper industry can transition from a linear to a circular bioeconomy and eco-friendly manage the kraft black liuor. This approach showed to be effective towards resource recovery, while simultaneously minimizing the environmental burden., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A new porous solid base catalyst was prepared using dewatered paper sludge and successfully employed to produce biodiesel from soybean oil. The as-prepared catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transforms infrared spectroscopy, X-ray photoelectron spectroscopy, thermal gravity/differential thermal gravity analysis, Brunauer-Emmet-Teller analysis, and CO 2 -temperature programmed analysis. The results showed that the formation of CaO and uniformly distributed porous structure should account for the high catalytic activity of the as-prepared catalyst. The optimum reaction conditions were observed at 180 ℃, 8 wt.% catalyst/oil weight ratio, 16:1 methanol/oil molar ratio, and 300 min reaction time with 91.6% biodiesel yield. After being used several times and recycled, the regenerated catalyst still exhibited effective catalytic activity without apparent deactivation. The kinetic study confirmed that the experimental data satisfied with Pseudo-first-order kinetic model controlled by reaction temperature and catalyst/oil weight ratio. The reaction activation energy was 24.98 kJ/mol. The change of enthalpy ΔH (14.98 kJ/mol), entropy ΔS (-208.57 J/mol/K), and Gibbs free energy ΔG (109.46 kJ/mol) indicated that the transesterification reaction catalyzed by the dewatered paper sludge-derived catalyst is endothermic, endergonic, and non-spontaneous. Our research finding indicated that the CaO-based catalyst derived from dewatered paper sludge was an economically promising and eco-friendly solid base catalyst for biodiesel production.

The pulp and paper industry (PPI) has several opportunities to contribute to meeting prevailing climate targets. It can cut its own CO2 emissions, which currently account for 2% of global industrial fossil CO2 emissions, and it has an opportunity to produce renewable energy, fuels, and materials for other sectors. The purpose of this study is to improve understanding of the decarbonization prospects of the PPI. The study provides insights on the magnitude of needed annual renewal rates for several possible net-zero target years of industrial fossil CO2 emissions in the PPI and discusses decarbonization opportunities, namely, energy and material efficiency improvement, fuel switching, electrification, renewable energy production, carbon capture, and new products. The effects of climate policies on the decarbonization opportunities are critically evaluated to provide an overview of the current and future business environment of the European PPI. The focus is on Europe, but other regions are analyzed briefly to widen the view. The analysis shows that there are no major technical barriers to the fossil-free operation of the PPI, but the sector renovates slowly, and many new opportunities are not implemented on a large scale due to immature technology, poor economic feasibility, or unclear political environment. [ABSTRACT FROM AUTHOR]

An innovative circular economy (CE) system was implemented at the wastewater treatment plant (WWTP) in Brunswick. The performance of the CE system was evaluated for 4 years: the thermal pressure hydrolysis enhanced the methane production by 18% and increased the digestate dewaterability by 14%. Refractory COD formed in thermal hydrolysis and increased the COD concentration in the WWTP effluent by 4 mg L -1 while still complying with the legal threshold. Struvite production reached high phosphorus recovery rates of >80% with a Mg:P molar ratio ≥0.8. Nitrogen was successfully recovered as ammonium sulfate with high recovery rates of 85-97%. The chemical analyses of secondary fertilizers showed a low pollutant content, posing low risks to soil and groundwater ecosystems. The total carbon footprint of the WWTP decreased due to enhanced biogas production, the recovery of renewable fertilizers and a further reduction of nitrous oxide emissions. Using green energy will be crucial to reach carbon neutrality for the entire WWTP., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).)

With increasing demand of fossil fuels and water pollution and their environmental impacts, marine green microalgae have gained special attention in both scientific and industrial  fields. This is due to their fast growth in non-arable lands with high photosynthetic activity, their metabolic plasticity, as well as their high CO 2 capture capacity. Tetraselmis species, green and eukaryotic microalgae, are not only considered as a valuable source of biomolecules including pigments, lipids, and starch but also widely used in biotechnological applications. Tetraselmis cultivation for high-value biomolecules and industrial use was demonstrated to be a non-cost-effective strategy because of its low demand in nutrients, such as phosphorus and nitrogen. Recently, phycoremediation of wastewater rich in nutrients, chemicals, and heavy metals has become an efficient and economic-alternative that allows the detoxification of waters and induces mechanisms in algal cells for biomolecules rich-energy synthesis to regulate their metabolic pathways. This review aims to shed light on Tetraselmis species for their different culture conditions and metabolites bioaccumulation, as well as their human health and environmental applications. Additionally, phycoremediation of contaminants associated to biofuel production in Tetraselmis cells and their different intracellular and extracellular mechanisms have also been investigated., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The present investigation has evaluated the use of effluents from a secondary municipal wastewater treatment plant for biomass production and potential of the biomass for biodiesel production. Cultivations of Chlorella vulgaris using wastewater, wastewater with supplementation, and WC medium were carried out. Effect of wastewater collected in different months on biomass productivity (BP) and lipid composition was studied. Methods based on NMR and GC-MS techniques were applied for determining the composition of the lipids and their fatty acid profile including poly unsaturated fatty acids (PUFAs). Lipids extracted are comprised of both neutral (tri acyl glycerides, TAG; free fatty acids, FFA) and polar (glyco glycero/phospho) lipids. The TAG content of the extracted lipids was determined in the range of 22.5-41.3% w/w. The NMR and GC-MS compositional results of microalgal lipids of biomasses cultivated in wastewater without nutrient supplementation, collected in different months, showed potential for biodiesel production. The fatty acid profiles of neutral and polar lipids, which are mainly comprised of saturated and unsaturated long alkyl chain (C16-C22) fatty acids, are potential sources for the biodiesel and food industry. The concentration of nitrates (45-78 mg L -1 ) in wastewater without supplementation, collected in different months, was found to be optimum to enable cultivation of biomasses with reasonably good BP of 21.5-28.1 mg L -1  day -1 . Similar results have been obtained in the present work as well as reported in the literature in the case of WC medium (nitrate, 69 mg L -1 ) with BP of 25.5-28.2 mg L -1  day -1 , thus highlighted the significance of the presented work., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Renewable and sustainable biofuel production, such as biobutanol, is becoming increasingly popular as a substitute for non-renewable and depleted petrol fuel. Many researchers have studied how to produce butanol cheaply by considering appropriate feedstock materials and bioprocess technologies. The production of biobutanol through acetone-butanol-ethanol (ABE) is highly sought after around the world because of its sustainable supply and lack of competition with food. The purpose of this study is to present the current biobutanol production research and to analyse the biobutanol research conducted during 2006 to 2023. The keyword used in this study is "Biobutanol," and the relevant data was extracted from the Web of Science database (WoS). According to the results, institutions and scholars from the People's Republic of China, the USA, and India have the highest number of cited papers across a broad spectrum of topics including acetone-butanol-ethanol (ABE) fermentation, biobutanol, various pretreatment techniques, and pervaporation. The success of biobutanol fermentation from biomass depends on the ability of the fermentation operation to match the microbial behaviour along with the appropriate bioprocessing strategies to improve the entire process to be suitable for industrial scale. Based on the review data, we will look at the biobutanol technologies and appropriate strategies that have been developed to improve biobutanol production from renewable biomass., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The use of nanomaterials in biofuel production from lignocellulosic biomass offers a promising approach to simultaneously address environmental sustainability and economic viability. This review provides an overview of the environmental and economic implications of integrating nanotechnology into biofuel production from low-cost lignocellulosic biomass. In this review, we highlight the potential benefits and challenges of nano-based biofuel production. Nanomaterials provide opportunities to improve feedstock pretreatment, enzymatic hydrolysis, fermentation, and catalysis, resulting in enhanced process efficiency, lower energy consumption, and reduced environmental impact. Conducting life cycle assessments is crucial for evaluating the overall environmental footprint of biofuel production. An economic perspective that focuses on the cost implications of utilizing nanomaterials in biofuel production is also discussed. A comprehensive understanding of both environmental and economic dimensions is essential to fully harness the potential of nanomaterials in biofuel production from lignocellulosic biomass and to move towards sustainable future energy., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Herbal waste produced during the manufacturing of herbal products is a potential feedstock for anaerobic digestion due to high amount of organic matter that can be transformed into biogas as an energy resource. Therefore, the present study was undertaken to convert herbal waste produced during the manufacturing of common of Ayurveda products into biogas through anaerobic digestion process using batch test study under controlled mesophilic temperature conditions of 35 °C with food to inoculum ratio of 0.75. The maximum biomethane potential (BMP) of 0.90 (gCH 4 COD/g COD fed ) and sludge activity of 0.70 (gCH 4 -CD/gVSS) was exhibited by WS herbal waste owing to its high chemical oxygen demand (COD) of 4 g/g and better solubilization potential of the organic matter showing change in volatile suspended solids (ΔVSS) of 79%. On the other hand, the waste derived from the TA herb, exhibited the least biogas yield of 0.55 (gCH 4 COD/g COD fed ) and sludge activity of 0.40 (gCH 4 -CD/gVSS), albeit with higher organic matter present. This was due to the possible hindrance of waste solubilization by the presence of lignin. The waste derived from VVL and PE showed intermediate BMP and sludge activity. The methane generation rate constant (k), a key indicator of the biodegradation potential, was also evaluated. The k values showed similar trend as of BMP values ranging from 0.081 to 0.15 d -1 thus indicating the influence of presence of lignin and the change in ΔVSS. The present study proves anaerobic digestion to be an alternative treatment method to be a milestone for management of herbal wastes and can be successfully implemented on real-scale systems., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The organic wastes and residues generated from agricultural, industrial, and domestic activities have the potential to be converted to bioenergy. One such energy is biogas, which has already been included in rural areas as an alternative cooking energy source and agricultural activities. It is produced via anaerobic digestion of a wide range of organic nutrient sources and is an essential renewable energy source. The factors influencing biogas yield, i.e., the various substrate, their characteristics, pretreatment methods involved, different microbial types, sources, and inoculum properties, are analyzed. Furthermore, the optimization of these parameters, along with fermentation media optimization, such as optimum pH, temperature, and anaerobic digestion strategies, is discussed. Novel approaches of bioaugmentation, co-digestion, phase separation, co-supplementation, nanotechnology, and biorefinery approach have also been explored for biogas production. Finally, the current challenges and prospects of the process are discussed in the review., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Anaerobic treatment of oily substrate, known as grease trap waste (GTW), was investigated for its practicability via continuous stirred tank reactor (CSTR) at different operating conditions and selected recovery strategies of feeding frequency efficacy. This study determine the performance of feeding frequency efficacy, namely feeding every 24 hours (R 24H ) and feeding every 12 hours (R 12H ). Under organic loading rate (OLR) of 2.2 gCOD/L.day, R 12H exhibited methane composition of 57%, methane production rate of 0.27 LCH 4 /L.day, and methane yield of 0.14 LCH 4 /gCOD removed . At the same OLR, R 24H recorded methane composition of 60%, methane production rate of 0.29 LCH 4 /L.day and similar methane yield as R 12H . Findings indicated that R 24H showed performance comparable to that of R 12H . Given minor variation observed in performance, it is recommended that plant operators may consider scheduling two feedings per day for low loading conditions and switch to one feeding per day for higher loading conditions. This strategy is designed to balance the system and prevent shock loads, which could lead to plant shutdowns. This mechanism will induce their conversion to volatile fatty acids (VFAs); thus, reducing the risk of acid accumulation and pH drops, which could inhibit methanogens to produce methane, especially for oily substrate., Competing Interests: The authors declare there is no conflict., (© 2024 The Authors This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY-NC-ND 4.0), which permits copying and redistribution for non-commercial purposes with no derivatives, provided the original work is properly cited (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

Biodiesel, a renewable and sustainable alternative to fossil fuels, has garnered significant attention as a potential solution to the growing energy crisis and environmental concerns. The review commences with a thorough examination of feedstock selection and preparation, emphasizing the critical role of feedstock quality in ensuring optimal biodiesel production efficiency and quality. Next, it delves into the advancements in biodiesel applications, highlighting its versatility and potential to reduce greenhouse gas emissions and dependence on fossil fuels. The heart of the review focuses on transesterification, the key process in biodiesel production. It provides an in-depth analysis of various catalysts, including homogeneous, heterogeneous, enzyme-based, and nanomaterial catalysts, exploring their distinct characteristics and behavior during transesterification. The review also sheds light on the transesterification reaction mechanism and kinetics, emphasizing the importance of kinetic modeling in process optimization. Recent developments in biodiesel production, including feedstock selection, process optimization, and sustainability, are discussed, along with the challenges related to engine performance, emissions, and compatibility that hinder wider biodiesel adoption. The review concludes by emphasizing the need for ongoing research, development, and collaboration among academia, industry, and policymakers to address the challenges and pursue further research in biodiesel production. It outlines specific recommendations for future research, paving the way for the widespread adoption of biodiesel as a renewable energy source and fostering a cleaner and more sustainable future., (© 2024. The Author(s).)

The current manuscript focuses on the advancements made in establishing zone-based biogas plants in India from 1990 to the present. India generates various types of waste from agricultural, industrial, and human activities. Several methods are available to manage and derive energy from these waste materials, such as incineration, gasification, and anaerobic digestion (AD). Among these options, AD stands out as one of the most viable and environmentally friendly alternatives for biogas production, thanks to its low energy consumption. However, developing biogas plants in developing countries faces significant challenges, primarily due to governments' inadequate application of policy, financial, social, market, information, and technical constraints. To compile this information, data from various agencies in India have been gathered, revealing that 1.81 million biogas plants are currently installed in the West Zone, 1.48 million in the South Zone, 1.106 million in the North Zone, and 0.65 million in the East Zone. These biogas plants across the zones generate 7.02 lakh m 3 per day. Additionally, 22 bio-CNG plants produce 84,759 kg/day of compressed biogas, and 201 waste plants generate 330.935 MW of electricity. Recently, the government has emphasized several initiatives, including GOBAR-DHAN, New National Biogas and Organic Manure, Sustainable Alternative Towards Affordable Transportation, and the waste-to-energy program. These initiatives aim to enhance the utilization of waste, promote cleanliness in villages and towns, and support the Swachh Bharat Mission and Atmanirbhar Bharat campaign, leading to tremendous overall success., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Agricultural waste residues (agro-waste) are the source of carbohydrates that generally go in vain or remain unused despite their interesting morphological, chemical, and mechanical properties. With rapid urbanization, there is a need to valorize this waste due to limited non-renewable resources. Utilizing agro-waste also prevents the problems like burning and inefficient disposal that otherwise lead to immense pollution worldwide. In addition, conversion of biomass to value-added products like earthen cups, weaving baskets, and bricks is equally beneficial for the rural population as it provides secondary income, creates jobs, and improves rural people's lifestyles. This review paper will discuss an overview of different applications utilizing agro-waste residues. In particular, agro-wastes used as construction material, bio-fertilizers, pulp and paper products, packaging products, tableware, heating applications, biocomposites, nano-cellulosic materials, soil stabilizers, bioplastics, fire-retardant additive, dye removal, and biofuels will be summarized. Finally, several commercially available agro-waste products will also be discussed, emphasizing the circular economy., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Strategic valorization of readily available sugarcane bagasse (SB) is very important for waste management and sustainable biorefinery. Conventional SB pretreatment methods are ineffective to meet the requirement for industrial adaptation. Several past studies have highlighted different pretreatment procedures which are lacking environmentally benign characteristics and effective SB bioconversion. This article provides an in-depth review of a variety of environmentally acceptable thermochemical and biological pretreatment techniques for SB. Advancements in the conversion processes such as pyrolysis, liquefaction, gasification, cogeneration, lignin conversion, and cellulose conversion via fermentation processes are critically reviewed for the formation of an extensive array of industrially relevant products such as biofuels, bioelectricity, bioplastics, bio adsorbents, and organic acids. This article would provide comprehensive insights into several crucial aspects of thermochemical and biological conversion processes, including systematic perceptions and scientific developments for value-added products from SB valorization. Moreover, it would lead to determining efficient pretreatment and/or conversion processes for sustainable development of industrial-scale sugarcane-based biorefinery., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

As the transition to renewable energy systems is accelerating, anaerobic digestion, which is one of the methods of energy recovery from organic substrates, continues to be studied with great interest by scientists. Anaerobic digestion research and applications are mostly carried out with biochemical methane potential (BMP) tests to decide the methane potency of sewage sludge, energy crops, and organic wastes. Unlike long and costly continually reactor experiments, actually, BMP tests are cumulative and can be performed with a relatively low investment of materials, technical labor, and also time. For the BMP to give accurate results, the effect of all the tools and technical parameters used in the implementation of the BMP should be well understood. In such situations, it is very useful to apply fuzzy logic methods in multi-criteria decision-making stages when more than one parameter changes at the same time. Therefore, in this study, fifteen parameters were determined and analyzed with the fuzzy DEMATEL (decision-making trial and evaluation laboratory) method to understand the cause-effect mechanism of the technical parameters of BMP. As a result of these analyses, it was seen that the material of the reactor (r i -c j value of 0.55), the particle size (r i -c j value of 0.43), the effect of mixing (r i -c j value of 0.32), and the amount of the total solids (TSA) (r i -c j value of 0.25) had a high effect in the causal sense. It was observed that the first-order parameter (material of reactor) was 27% stronger than the second-order (the particle size) parameter in terms of causality. Likewise, the second-order parameter is 34% stronger than the third-order parameter (the effect of mixing) in terms of cause effect. In addition, it was understood that the most effective parameters in the mechanism of effect were pH (r i  + c j value of 3.41), C/N ratio (r i  + c j value of 3.26), and temperature (r i  + c j value of 3.07), respectively. Besides, high methane yield is seen in mesophilic conditions. The average cumulative biogas yield of the reactor is 282.1 NmL/g VS. The highest percentage of methane formed in the biogas occurred on the 21st day. Briefly, this study is important to provide a facilitating way for researchers working on BMP to understand the cause-effect mechanism of system technical requirements., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Encouraging rural residents to adopt biogas is of great practical significance in tackling environmental degradation in China. Based on the survey data of 540 rural households in Sichuan Province, China, this paper studies the peer effects of biogas adoption in rural households, focusing on the influence of relatives and friends on the biogas adoption behavior of rural households. According to whether there is a Chinese New Year visit, the relatives and friends of rural households are divided into strong ties and weak ties. The peer effects are further discussed from the perspective of strong and weak ties, and the probability score matching (PSM) method is used to correct the estimation errors that may be caused by selection bias. In addition, the study further revealed the internal mechanism of peer effects through heterogeneity analysis. The results found that (1) the adoption of biogas by relatives and friends significantly promotes the adoption of biogas in rural households. (2) Compared with relatives and friends who did not visit during the Chinese New Year (weak ties), relatives and friends who visited (strong ties) had a more significant impact on the biogas adoption behavior of rural families. (3) Farmer groups with lower education levels and farther from the market are more affected by the peer effects and are more likely to adopt biogas. The driving effect of biogas behavior choice of relatives and friends on biogas behavior decision of rural households can provide a reference for decision-makers to make relevant measures., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In 2009, Pakistan introduced a subsidized biogas program to disseminate clean and affordable energy in rural areas. However, the adoption rate did not appear as expected. Therefore, the present study aims to examine the determinants behind the non-adoption of biogas digesters. Detailed information via a structured questionnaire was obtained from biogas adopters and non-adopters, and analyses were performed in two levels. Initially, the study used the multinomial logit regression to elicit the non-adoption behavior. Results depicted family size, risk aversion, cook education (women), kitchen (inside the home), home structure, and non-availability of inputs as significant factors behind non-adoption. Detailed analysis also revealed that the factors like the age of household head, area of the house, cook education (women), location of the kitchen (inside the home), and the distance of the house to the bus stop (minutes) lead towards the potential adoption of biogas. The study also investigated the potential factors behind the long-term sustainability of biogas digesters with the help of binary logit. The results depicted that the kitchen's location (inside the house), cook education (women), training, and subsidy significantly and positively impact the biogas plant's probability of being functional. Based on these results, the study suggested that policymakers increase women's education in rural areas, provide a subsidy to reduce costs and risk, and arrange training for adopters., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study aimed to synthesize the biodiesel from Mastic oil by electrolysis method. Mastic gum is a potential and inexpensive feedstock for the biodiesel production. The oil content of Mastic gum was ~ 20% of the total gum weight. The gas chromatography-mass spectrometry (GC-MS) analysis was exploited to measure the oil's fatty acid profile. The response surface methodology (RSM) via Box-Behnken design (BBD) was utilized to specify the best processing condition of the electrolytic transesterification process. According to the RSM-BBD results, the highest predicted biodiesel yield was 95% at the reaction time of 1 h, methanol to oil ratio of 4:1, and catalyst weight of 1.2 wt%. Under these conditions, the produced Mastic oil biodiesel was blended with the neat diesel at different volume ratios of 5:95 (B5), 10:90 (B10), and 15:85 (B15). These fuel mixtures were tested in a single-cylinder engine to assess engine performance and exhaust emissions. The experiments exhibited that blending biodiesel with diesel can slightly improve the engine performance. Moreover, the application of blends with high volumes of biodiesel decreased the exhaust emissions, such as carbon monoxide (CO), carbon dioxide (CO 2 ), and unburned hydrocarbons (UHC) by 54.54%, 41%, and 39.3%, respectively. However, the nitrogen oxide (NO x ) emission increased because of the higher oxygen content of the biodiesel. It was also found that the physical and chemical characteristics of the Mastic oil biodiesel are the same as diesel, consistent with the ASTM standard. The Fourier transform infrared (FTIR) analysis also confirmed the biodiesel production., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Hydrogen production from biological processes has been hailed as a promising strategy for generating sustainable energy. Fermentative hydrogen production processes such as dark and photofermentation are considered more sustainable and economical than other biological methods such as biophotolysis. However, these methods have constraints such as low hydrogen yield and conversion efficiency, so practical implementations still need to be made. The present review provides an assessment and feasibility of producing biohydrogen through dark and photofermentation techniques utilizing various lignocellulosic biomass wastes as substrates. Furthermore, this review includes information about the strategies to increase the productivity rate of biohydrogen in an eco-friendly and sustainable manner, like integration of dark and photofermentation techniques, pretreatment of biomass, genetic modification of microorganisms, and application of nanoadditives., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Future global energy demand may be met through increased extraction of fossil fuels and production of renewable energy such as biofuels. Renewable energy from biofuels is often proposed as an environmentally friendly alternative to fossil fuels; however, impacts of renewable energy sources on wildlife populations have rarely been evaluated in working landscapes. We used North American Breeding Bird Survey data (1998 to 2021) to assess whether the joint effects of oil and gas and biofuel crop production explained grassland bird population declines. We modeled location-specific effects of land use on grassland bird habitat use for four grassland bird species (bobolink [Dolichonyx oryzivorus], grasshopper sparrow [Ammodramus savannarum], Savannah sparrow [Passerculus sandwichensis], and western meadowlark [Sturnella neglecta]) in North Dakota, a state experiencing rapid growth in both energy sectors. Our analysis showed that grassland birds responded more negatively to biofuel feedstocks (i.e., corn and soybeans) on the landscape compared with oil and gas development. Furthermore, we found that the effect of feedstocks was not generalizable to other forms of agricultural land use. When combined, these land use changes resulted in distributional shifts of grassland birds, with use by birds being lower in regions dominated by biofuel production, which appears partially responsible for observed abundance trends at the state level. Our results indicate that expansion of oil and gas development has negatively affected habitat use by some grassland birds, but this impact was more localized when compared to biofuel crops. Conservation practitioners may need to adapt their conservation strategies to account for widespread and rapid land use change driven by United States energy policies., (Published 2023. This article is a U.S. Government work and is in the public domain in the USA.)

In this study, palm oil mill effluent (POME) treated by ultrasonication at optimum conditions (sonication power: 0.88 W/mL, sonication duration: 16.2 min and total solids: 6% w/v) obtained from a previous study was anaerobically digested at different hydraulic retention times (HRTs). The reactor biomass was subjected to metagenomic study to investigate the impact on the anaerobic community dynamics. Experiments were conducted in two 5 L continuously stirred fill-and-draw reactors R1 and R2 operated at 30 ± 2 °C. Reactor R1 serving as control reactor was fed with unsonicated POME with HRT of 15 and 20 days (R1-15 and R1-20), whereas reactor R2 was fed with sonicated POME with the same HRTs (R2-15 and R2-20). The most distinct archaea community shift was observed among Methanosaeta (R1-15: 26.6%, R2-15: 34.4%) and Methanobacterium (R1-15: 7.4%, R2-15: 3.2%). The genus Methanosaeta was identified from all reactors with the highest abundance from the reactors R2. Mean daily biogas production was 6.79 L from R2-15 and 4.5 L from R1-15, with relative methane gas abundance of 85% and 73%, respectively. Knowledge of anaerobic community dynamics allows process optimization for maximum biogas production., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Turkey, as an energy importing country, is heavily dependent on fossil fuels, bringing about an escalation in environmental problems and raising concerns regarding energy security. However, biowastes offer a potential solution to these woes, especially in Marmara Region of the country. In this study, the region's potential in terms of the use of waste for energy production is analyzed. Within this context, agricultural and livestock wastes are examined in terms of their amounts, theoretical energy potentials, and associated costs to generate electricity. To evaluate economic costs, collection and feedstock costs for animal and agricultural wastes are used as input in three different scenarios based on FAO's assessment. Based on the waste volumes and energy potentials thereof, it is found that biowastes can theoretically meet more than half of the electricity demand of the region. The results of the cost analysis demonstrate that both direct combustion of agricultural wastes and conversion of animal wastes to biogas in CHP plants to produce electricity are cost-effective in the context of various scenario options, considering the LCOE and feed-in-tariff values., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The present experimental work is carried out to analyse the performance, combustion, and exhaust emission characteristics of variable compression ratio (VCR) diesel engine using blended biofuel (B20) with nanoadditives. Transesterified biodiesel was prepared from waste cooking oil (WCO). The cerium oxide nanoparticles (CERIA) were produced and categorized by precipitation technique, SEM and XRD analysis. These nanoadditives mixed with biofuel blend by magnetic stirrer and then by ultrasonication. The test procedure was carried out under the following fuel blends: 20% of biodiesel added to 80% diesel (B20), 15ppm, 30ppm, 45ppm, 60ppm and 75ppm cerium oxide nanoparticles added with B20 blend (diesel, B20, B20+CERIA15, B20+CERIA30, B20+CERIA45, B20+CERIA60, B20+CERIA75). The engine was operated at fixed compression ratio 20:1 and constant speed at various load conditions 0%, 25%, 50%, 75% and 100%, and results were compared to diesel at 100% load. The improvement in B20 fuel characteristics was observed by adding cerium oxide nanoparticles. The outcomes indicate better improvement in the blended sample of B20+CERIA45 ppm with brake thermal efficiency increased by 3.62% and specific fuel consumption decreased by 3.3% than the neat diesel. Presence of added particles gives better atomization which prompts total burning in the combustion chamber and builds up the amplified pressure data. The emission of CO and HC outflow dimnishes by the addition of CERIA nanoparticles in blended biofuel. Additionally, there is a reduction in NO x by expanding the CERIA dosage in the fuel mixer. This occurs due to CERIA particles presented in a fuel blend behaving as an oxygen buffer and engaging the O 2 for decreasing the NO x formation., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To improve the biogas yield of rice straw, an innovative cascade utilization process for biogas production was proposed using a method referred to as "the first digestion + NaOH treatment + the second digestion" (labeled FSD). Both the first digestion and the second digestion of all treatments were conducted at the initial total solid (TS) loading of straw of 6%. A series of lab-scale batch experiments were conducted to investigate the effect of first digestion time (5, 10, and 15 days) on biogas production and lignocellulose structure destruction of rice straw. The results showed that the cumulative biogas yield of rice straw using the FSD process was increased by 13.63-36.14% compared with the control (CK), and the highest biogas yield of 233.57 mL g -1 TS added was obtained when the first digestion time was 15 days (FSD-15). The removal rates of TS, volatile solids, and organic matter were increased by 12.21-18.09%, 10.62-14.38%, and 13.44-16.88%, respectively, compared with those of CK. The results of Fourier transform infrared spectroscopy analysis revealed that the skeletal structure of rice straw was not significantly destroyed after the FSD process, but the relative contents of functional groups in rice straw were changed. The FSD process accelerated the destruction of crystallinity of rice straw, and the lowest crystallinity index of 10.19% was obtained at FSD-15. The abovementioned results indicated that the FSD-15 process is recommended for cascade utilization of rice straw in biogas production., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study aims to identify current and future research trends in sustainable bioenergy production. The systematic review is conducted using a social network analysis method. The data were collected from the Web of Science and Scopus database (2010-2021). Out of the 1747 articles reviewed, 100 were found to be relevant for thematic analysis. The results uncovered four domains of palm oil biodiesel production for sustainable energy management: (1) renewable energy, (2) biodiesel, (3) bioenergy, and (4) life cycle assessment. This study has proposed a sustainable bioenergy production framework based on the four main domains. The framework sheds light on the future of sustainable bioenergy production. The findings indicate the potential growth of the research topic, including sustainable bioenergy, palm oil biodiesel, energy management, and carbon emissions reduction. Future research must incorporate the energy management framework to design a sustainable energy management ecosystem strategy. In addition, the industry must comply with the international sustainability standard and sustainable development goals to manage the energy supply chain and consistency of palm oil biodiesel production., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biomass energy contributes nearly 14% of the total global energy. Therefore, biomass briquettes can be effectively considered an alternate source of fossil fuels. The present study aims at utilizing Senna auriculata and Ricinus communis waste generated locally for the production of biomass briquettes with 10% of tapioca starch as binder. The biomass wastes are blended at various proportions such as 0:100 (S1), 25:75 (S2), 50:50 (S3), 75:25 (S4) and 100:0 (S5) respectively, and the concentration of binder was maintained to be constant. The characterization of the prepared biomass briquettes includes the analysis of physical characteristics, proximate analysis, elemental analysis, SEM analysis, thermogravimetric analysis, differential scanning calorimetric analysis and XRD analysis. The results of the proximate analysis have revealed that the biomass briquettes possess lower percentage in terms of moisture content, ash content, sensible fixed carbon and high percentage of volatile matter content. Energy dispersive X-ray analysis has shown that the carbon and oxygen are the major elements for all the biomass briquettes. SEM analysis has revealed that the surface of the biomass briquettes is identified with irregular surface, lumps, cavities and few deposits of carbon particles. Thermogravimetric analysis and DSC analysis have reconfirmed the spontaneous burning characteristics of biomass briquettes. XRD analysis has proved that the bonding between each element present in the biomass briquettes is either monoclinic, tetragonal, orthorhombic or anorthic., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This paper investigates the transformation challenges related to incumbent industries caused by technology development and industry convergence in the transition to a bioeconomy in the context of Swedish biorefinery development. It involves the emergence of new value chains and several incumbent industries such as the pulp and paper industry, the oil refinery sector, the chemical process industry, and the heat and power sector. In 2019, Sweden had Europe's largest share of biofuels in the transport sector, roughly 20% on an energy basis, and this share has increased by around 300% during the last decade. At the same time, domestic production has stalled, and even though Sweden has beneficial conditions for biofuel production, the share of biofuel that is imported or based on imported feedstock has recently ranged between 85% and 90%. We discuss three transformation challenges: (i) inertia and lack of absorptive capacity creating lock‐in effects at the organizational level; (ii) weak and inefficient actor networks at the industry level; and (iii) contradictory policy instrument mixes and lack of coordination at the government level. The findings underscore the need for policy integration and alignment across various policy domains, and an increased focus on policy mixes that can stimulate the emergence of more disruptive innovations and value chains. There is also a need for industrial initiatives, such as improving absorptive capacity and strengthening actor networks, to help build the value chains needed to realize a sustainable bioeconomy. 2021 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd [ABSTRACT FROM AUTHOR]

Exploring energy use-growth nexus can proffer valuable clues to policymakers and stakeholders on both economic and environmental sustainability targets. Unlike extant studies, this study focuses on the effects of renewable energy consumption on the economic progress of the Nordic countries including Denmark, Sweden, Norway, Finland, and Iceland. The empirical analysis encompasses two distinctive renewable energy consumption indicators while accounting for influential factors like research and development (R&D) expenditures, and both human and physical capital components within the traditional growth model framework. The DCCE estimator was deployed for the empirical analysis covering the available sample data between 1995 and 2020. From the results, the estimated impact of renewable energy consumption on economic progress varies according to its measurement vis-à-vis the utilized indicator 1 (renewable as % of total energy use) and indicator 2 (distinctive renewable power sources and biofuels). In the case of the former indicator, the impacts were insignificant while a positive significant impact on growth was seen across all model evaluations using both the GDP and per capita income levels of the Nordic countries in the latter indicator. Furthermore, both R&D expenditures and human capital component are essential significant long-run drivers of both economic growth and income levels in the bloc while physical capital formation produced contrary evidence on economic progress in the bloc. As such, policy implications and recommendations to enhance economic progress were suggested in the main text for the Nordic countries in view of renewable energy development and the bloc's environmental sustainability drive. Notably, strategic policy implementation should be geared towards encouraging more R&D expenditures, especially in renewable energy developments to facilitate economic growth and income levels while further positioning the Nordic bloc on environmental sustainability path., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Clostridium thermocellum has been studied as a model organism that is highly specialized in cellulose deconstruction, and in secretion of cellulolytic enzymes organized into an enzymatic complex known as the cellulosome. Lignocellulose deconstruction requires a variety of enzymes, including cellulases, hemicellulases, and pectin-degrading enzymes. In addition to cellulase production, C. thermocellum is an efficient producer of xylanases, which can be found as cellulosome components. These enzymes work in synergy with cellulosomal cellulases to effect complete hydrolysis of holocellulose. Xylan-degrading enzymes are highly sought after for industrial applications, including production of biofuels and paper and pulp. In this context, industrial processes could take advantage of the properties of xylanases derived from C. thermocellum, such as thermal stability and specificity for different xylans. In this review, we describe the potential of C. thermocellum in degrading xylan-based polymers by reviewing the main findings regarding xylan-degrading enzymes synthesized by this organism, including the repertoire of substrates that can be synergically hydrolyzed through the action of distinct glycoside hydrolase (GH) families. Features of these enzymes, including their modular architecture, specificity for different xylan polymers, and biochemical properties, are discussed. Custom-tailored xylanosomes employing the xylan specificity of GH from families 30, 5, 10, and 11 are proposed as enzymatic machinery for more efficient hemicellulose deconstruction. [ABSTRACT FROM AUTHOR]

Alternate fuels are in great need as the world's natural resources are depleting with continuous consumption. Furthermore, with a continuous increase in the use of conventional fuel which emits a large number of harmful pollutants to the environment and thus increasing global warming, the need for alternative fuel is in great need. This investigation thus focused on the impact identification on the use of biodiesel from fish waste-based biodiesel [BDWFO (Bio-Diesel of Waste Fish Oil)] with Nanoparticles in single cylinder water cooled IC engine. The fish wastes in fish processing industries/fish markets are used to produce oil and its biodiesel is produced by the transesterification method. The individual BDWFO, Diesel, and blends of 20% of BDWFO were tested with the engine. Then another two combinations of fuel created 200 ppm of 40 nm Aluminium Oxide nanoparticles (AN) mixed with BDWFO, blends of 20% of BDWFO. These five fuels were considered to study the engine performance, combustion, and emissions from the exhaust. The experimental results confirmed the presence of aluminium oxide nanoparticles in BDWFO provides improved engine performance and reduced emissions from exhaust gas except for CO 2 ., (© 2022. The Author(s).)

The uncontrolled industrialization and unrestricted textile production combined with inappropriate effluent treatment services in developing countries like Pakistan have multiplied the number of harmful effluent discharge. These effluents are enriched with dyes, heavy metal ions, and other hazardous materials that are poisonous and carcinogenic to living organisms. For that reason, the utilization of economic and efficient control techniques against such pollutants is imperative to protect natural resources. The triple algal role for phycoremediation of textile effluent was utilized in this study to make it suitable for irrigation and higher biofuel production. Locally isolated two strains, CKW1 (Spirogyra sp.) and PKS33 (Cladophora sp.), were used to treat the effluent collected from the direct outlets of the textile industries. The treated effluent was then tested for its toxicity and applied to wheat at initial stage grown under axenic conditions to check its effect on wheat (Triticum aestivum L.) vegetative growth and development. Finally, the algal biomass obtained after treatment was subjected to trans-esterification for predicting the amount of biodiesel production. Study outcomes revealed that the algal strains were able to decolorize the effluent entirely within 96-120 h. Compared to un-treated textile effluent, the phycoremediated wastewater application to wheat plants enhanced the plant biomass by 80%. Lastly, the production of biodiesel from algal biomass attained after phycoremediation was 35% less to algal biomass obtained under normal growth conditions. It can be concluded that the algal use helps to treat the contaminated effluent and marks them re-usable for irrigating plants and producing biomass which could be utilized for biodiesel production., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Macroalgae are an important source of food, fertilizer, hydrocolloids, and healthful bioactive components. Macroalgae are also being considered sources of biofuels, which require minimal demands for arable land, fresh water, or fertilizers. In this study, we explored the possibility of developing a red seaweed biorefinery process to extract carrageenan while producing chemical or biofuel co-products derived from the carrageenan extraction wastes. A common approach to processing organic wastes is to generate biogas; however, in this study, we targeted a potentially higher value option by applying acidogenic digestion to convert extraction wastes to carboxylic acids and derived compounds. Using an open culture of microorganisms, wastes from a carrageenan extraction plant were converted to mixed carboxylic acids, which were then neutralized and thermally decomposed to a variety of ketones. Batch digestions of the wastes were carried out at temperatures of 35 °C and 55 °C. Either calcium carbonate or ammonium bicarbonate was used as buffer. A solid-liquid counter-current percolation fermentation was operated in four stages at 35 °C. Digestion produced carboxylic acids ranging in chain length from one to seven carbons. The mesophilic temperature gave higher carboxylic acid yield and longer chain acids, with the highest acid titer reaching 18 g L -1 . Thermal decomposition of carboxylate salts produced a mixture of ketones which contained acetone, 3-pentanone, 2-hexanone, 2-heptanone, 3-heptanone, and 4-octanone as major products. These ketones could be sold as chemicals or hydrogenated to form corresponding chain length secondary alcohols which deliver higher energy density than ethanol., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Agro-industries, leveraged by the high demand of acai products, promote environmental impact through the generation of wastes in several locals in Amazon. The use with bioenergetic purposes has capacity to mitigate these scenario. Thus, the aim of the study was to characterize the biomass of acai seeds and establish the technical parameters of temperature and pressure of work to the production of briquettes of physical, mechanical and thermal quality. Temperatures of 120, 140 and 160 °C; and pressures of 15, 20 and 25 MPa were studied. We analyzed the briquettes mechanical compressive strength, rate of water absorption, rate of volumetric expansion and energy and apparent density. To the characterization of in natura seeds, the proximate analysis, chemical composition (extractives, holocellulose and lignin contents), higher, lower and useful heating value were determined. The proximate analysis indicated biomass thermal resistance, potential to direct burning and conversion by thermochemical processes. The lignin content may increase briquettes compressive strength produced in high temperatures. It was observed that the temperature had more influence in the evaluated briquettes characteristics than the pressure. The compressive strength was greater in 160 °C and 15 MPa briquettes, indicating that the lignin works as binder in this temperature, however, with pressure improvement the resistance is not favored due to the limit of resistance to compaction. The rate of water absorption decreased with the pressure increase and the temperature statistically affected in 140 °C briquettes. We observed volumetric expansion values in consonance to other found in dense biofuels of the literature. Further, the apparent density and energy density were favored by pressure improvement and the temperature helped in the increase of the apparent density. Moreover, the produced briquettes presented gain in the apparent density regarding the in natura biomass and had energy density comparable to coal and adequate to co-firing in boilers., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biodiesel generated by transesterification of triglycerides from renewable sources is a clean form of energy that is currently used in many countries in blends with petrodiesel. It is mainly produced from food-grade vegetable oils obtained from oleaginous crops. High prices of these oils have made the sustainability of biodiesel production questionable. The use of nonedible feedstocks, such as intracellular triglycerides accumulated by oleaginous yeasts, appears as a feasible alternative. However, it has been demonstrated that an economically sustainable production of yeast oil could only be possible if low-cost media based on industrial subproducts, or wastes are used. In this work, we propose intracellular lipids production by a previously selected oleaginous yeast strain in a medium composed only by sugar cane vinasse and crude glycerol. Different culture strategies were studied. The highest biomass and lipid yields were obtained when the yeast R. graminis S1/2R was cultivated in batch without control of dissolved oxygen. The fatty acid methyl esters obtained under these conditions met the specification of international biodiesel standards., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Global warming and increasing environmental pollution have become global concerns that, coupled with the scarcity of traditional forms of energy, have motivated the implementation of more sustainable production systems, such as biorefineries. This is because biorefineries are capable of integrating technologies and processes in a single facility, generating biofuels, value-added chemicals, and energy. Thus, the aim of the study was to investigate the bioproducts and emergent technologies surrounding the processing of corn into bioethanol and refined oil. A bibliometric analysis he was carried out in order to construct and evaluate prospective scenarios related to corn biorefineries. An analysis of the proposed layouts highlighted flexibility in the production process, given that one raw material could be transformed into various bioproducts. Thus, the results presented provide a bibliographic foundation for future studies on integrating residues-processes-products in corn processing. The reason for this is that the technological routes presented could be considered incremental innovations to develop a biorefinery, which takes place gradually, given that highly integrated biorefineries are highly complex. [ABSTRACT FROM AUTHOR]

In the past few years, the extraction of value-added compounds from the anaerobic digestion of glycerol has been an option to add value to this waste because biodiesel production is increasing worldwide. The evolution of research on glycerol valorization by anaerobic digestion has reached the use of high-rate reactors. However, no study has evaluated glycerol digestion in an anaerobic fluidized bed reactor (AFBR), a configuration with potential advantages in methane production. Still, the best operating temperature for high-rate glycerol digestion remains unclear. To clarify these gaps, the present study aimed to compare glycerol digestion in mesophilic AFBR (30 °C) and thermophilic AFBR (55 °C). In both reactors, glycerol concentration was increased from 1.0 to 7.0 g L -1 at a fixed hydraulic retention time of 24 h, resulting in an increase at the organic loading rate from 1.2 to 7.6 kg COD m -3 day -1 . Thermophilic digestion of glycerol achieved superior removals of organic matter (67.7-94.2%) and methane yield (330.8 mL CH 4 g -1 COD) than the mesophilic digestion (48.6-93.0% and 266.6 mL CH 4 g -1 COD). Additionally, the application of the kinetic model of substrate utilization (modified Stover-Kincannon model) indicated a higher substrate utilization coefficient in the thermophilic AFBR (23.09 g L -1 day -1 ) than the mesophilic AFBR (7.14 g L -1 day -1 ). Therefore, the application of glycerol concentrations higher than 7.0 g L -1 in thermophilic AFBR should be further investigated. Also, given only operational results, the application of the AFBR in the two-stage anaerobic digestion of glycerol is recommended., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The total number of inhabitants on the Earth is estimated to cross a record number of 9 × 10 3 million by 2050 that present a unique challenge to provide energy and clean environment to every individual. The growth in population results in a change of land use, and greenhouse gas emission due to increased industrialization and transportation. Energy consumption affects the quality of the environment by adding carbon dioxide and other pollutants to the atmosphere. This leads to oceanic acidification and other environmental fluctuations due to global climate change. Concurrently, speedy utilization of known conventional fuel reservoirs causes a challenge to a sustainable supply of energy. Therefore, an alternate energy resource is required that can maintain the sustainability of energy and environment. Among different alternatives, energy production from high carbon dioxide capturing photosynthetic aquatic microbes is an emerging technology to clean environment and produce carbon-neutral energy from their hydrocarbon-rich biomass. However, economical challenges due to low biomass production still prevent the commercialization of bioenergy. In this work, we review the impact of fossil fuels burning, which is predominantly used to fulfill global energy demand, on the quality of the environment. We also assess the status of biofuel production and utilization and discuss its potential to clean the environment. The complications associated with biofuel manufacturing using photosynthetic microorganisms are discussed and directed evolution for targeted phenotypes and targeted delivery of nutrients are proposed as potential strategies to increase the biomass production., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Sustainable power generation for portable electronic devices is of high interest due to increasing energy demands. Miniaturized biofuel cells are well-reported for this purpose where ubiquitous fluids, like glucose or lactate, can be leveraged. However, such biofuel cells need enzymes to complete the catalysis, leading to many prevalent issues like the longevity of enzymes, complicated immobilization, additional mediators etc. Therefore, non-enzymatic glucose biofuel cells (NEGBFCs) are gaining interest due to their cost-effectiveness, high repeatability and excellent stability. However, based on our best knowledge such glucose biofuel cells are not reported in microfluidic environment, and therefore their potential is not exploited. Realization of the functionality of such NEGBFCs in a microscale is crucial to replace them with their enzymatic counterparts. In this work, for the first time, a microfluidic non-enzymatic glucose biofuel cell (μNEGBFC) is developed on a paper-based platform using metallic catalysts. The catalysts for electrocatalytic energy generation is fabricated using electrodeposition method and their detailed physicochemical characterizations are done. The μNEGBFC is capable of producing a power density of 12.5 μW/cm2 with a stable potential of 410 mV. This green power output can be used to operate low-power micro-devices and lab-on-chip sensors in a more continual and viable manner. [Display omitted] • A simple, cost-effective electrodeposition technique was used for electrode fabrication. • Gold deposited anode and copper deposited cathode were used as electrodes. • A paper-based Microfluidic Non-Enzymatic Biofuel Cell (μNGBFC) was constructed. • The developed μNGBFC generated a power density of 12.5 μW/cm2. • The μNGBFC was capable of retaining 56% of the initial power after 72 h. [ABSTRACT FROM AUTHOR]

A shift from fossil fuels to renewable energy sources is essential to reduce global greenhouse gas emissions and climate change effects. Biofuels represent a promising low-carbon alternative for sectors that are hard to electrify, such as freight transport or aviation. This work investigates possible pathways for increasing the value of biomass at a Kraft pulp mill, focusing on black liquor and bark streams. Mathematical programming is coupled with superstructure optimization and systematic solution exploration to identify meaningful process configurations. The analysis of solutions under market variations allows for the identification of robust and competitive configurations for the co-production of pulp and fossil fuel alternatives. The results show that the integration of biorefineries in pulp mills results in better resource use and higher energy efficiency - diversifying the product portfolio and providing bio-based fuel products to the market while being economically viable. By incorporating fuel production in the conventional Kraft process, the carbon conversion efficiency of the mill can be increased from 48% to up to 67%. Extending the analysis, up to 2% of the European road freight transportation fuel could be provided with combined pulp and fuel production, and 5% of the worldwide fuel demand for passenger aviation.