V. Vu, Csilla Kohári-Farkas, Róbert Filep, Gábor Laszlovszky, My Thi Ban, E. Bujna, V.K. Gupta, Quang D. Nguyen
Cellulose-rich agricultural residues are promising renewable sources for producing various value-added products such as 2nd generation biofuels. However, the efficiency of the bioconversion process is not always satisfactory due to the slow and incomplete degradation of lignocellulosic biomass. An interesting approach would be using microbial communities with high lignocellulose-degrading ability for environmentally friendly pretreatment. This study focused on characterizing the degradation performance of bacteria, fungal, and yeast strains and designing and constructing different microbial consortia for solid-state treatment of wheat bran and wheat straw. The microbial consortia, namely BFY4 and BFY5, contained different bacteria, fungal, and yeast led to high ratios of sugar accumulation ranging from 3.21 to 3.5 with degradation rates over 33%, owing to more favorable hydrolytic enzyme activities and improved reducing sugar yield during the process. After 72 h, the highest FPase (0.213 IU/gds) and xylanase (7.588 IU/gds) activities were also detected in the wheat straw pretreated by BFY4 and BFY5, respectively, while CMCase activity peaked (0.928 IU/gds) when wheat bran was used as substrate. The amount of released glucose increased during the treatment process when the two substrates were used in the same ratio. Our results indicated that substrate composition also plays an important role in the degradation capacity of mixed cultures. These findings can be instrumental in advancing the primary knowledge required to apply such bioprocesses at the pilot scale.
{"title":"Design and construction of artificial microbial consortia to enhance lignocellulosic biomass degradation","authors":"V. Vu, Csilla Kohári-Farkas, Róbert Filep, Gábor Laszlovszky, My Thi Ban, E. Bujna, V.K. Gupta, Quang D. Nguyen","doi":"10.18331/brj2023.10.3.3","DOIUrl":"https://doi.org/10.18331/brj2023.10.3.3","url":null,"abstract":"Cellulose-rich agricultural residues are promising renewable sources for producing various value-added products such as 2nd generation biofuels. However, the efficiency of the bioconversion process is not always satisfactory due to the slow and incomplete degradation of lignocellulosic biomass. An interesting approach would be using microbial communities with high lignocellulose-degrading ability for environmentally friendly pretreatment. This study focused on characterizing the degradation performance of bacteria, fungal, and yeast strains and designing and constructing different microbial consortia for solid-state treatment of wheat bran and wheat straw. The microbial consortia, namely BFY4 and BFY5, contained different bacteria, fungal, and yeast led to high ratios of sugar accumulation ranging from 3.21 to 3.5 with degradation rates over 33%, owing to more favorable hydrolytic enzyme activities and improved reducing sugar yield during the process. After 72 h, the highest FPase (0.213 IU/gds) and xylanase (7.588 IU/gds) activities were also detected in the wheat straw pretreated by BFY4 and BFY5, respectively, while CMCase activity peaked (0.928 IU/gds) when wheat bran was used as substrate. The amount of released glucose increased during the treatment process when the two substrates were used in the same ratio. Our results indicated that substrate composition also plays an important role in the degradation capacity of mixed cultures. These findings can be instrumental in advancing the primary knowledge required to apply such bioprocesses at the pilot scale.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":" ","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43910134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mokhtar Mokhtar, Anis Sukmono, H. Setiapraja, Muhammad Ma’ruf, S. Yubaidah, ihwan haryono, Budi Rochmanto, Respatya Teguh Soewono, Kurnia Fajar Adhi Sukra, Arfi Thahar, Efendi Manurung, Cahyo Setyo Wibowo, Setyo Widodo, Faqih Supriyadi, Riva Yudha Abriyant, Dedi Suntoro, Faridha Faridha, I. Reksowardojo
This research focused on evaluating the technical viability of using biodiesel with a blending ratio of 40% v/v, which is expected to be implemented soon in Indonesia. Two kinds of biodiesel blends were prepared, a blend of 60% diesel fuel and 40% biodiesel (B40) and a blend of 60% diesel fuel, 30% biodiesel, and 10% hydrogenated vegetable oil (HVO) (B30D10). The fuels were tested on EuroII vehicles without any engine modifications through a 50,000 km endurance road test. Laboratory tests were also performed at certain traveled distances to evaluate various engine parameters, including power, fuel economy, exhaust emissions, and used engine oil properties. Engine components were inspected upon the completion of the road test. Cold-start ability was also examined to confirm the suitability of the investigated biofuels at low-temperature operating conditions in Indonesia. The road test results showed that vehicles fuelled with B40 and B30D10 could reach a distance of 50,000 km without encountering any technical issues. The laboratory evaluation during the road test indicated that B30D10 had a higher power and fuel economy than B40, with a maximum difference of 2%. Furthermore, B30D10 emitted lower CO, HC, and PM emissions than B40 throughout the distance traveled, with maximum differences of 11.4%, 14.7%, and 22.6%, respectively, but led to 15% higher NOx. Engine component inspection and used engine oil analysis confirmed the fulfillment of the manufacturer's recommendations for both B40 and B30D10. Finally, B40 and B30D10 were suitable for operating at low ambient temperatures in Indonesia, confirming them as practical options to be implemented in the nationwide 40% biodiesel blend fuel.
{"title":"Towards nationwide implementation of 40% biodiesel blend fuel in Indonesia: a comprehensive road test and laboratory evaluation","authors":"Mokhtar Mokhtar, Anis Sukmono, H. Setiapraja, Muhammad Ma’ruf, S. Yubaidah, ihwan haryono, Budi Rochmanto, Respatya Teguh Soewono, Kurnia Fajar Adhi Sukra, Arfi Thahar, Efendi Manurung, Cahyo Setyo Wibowo, Setyo Widodo, Faqih Supriyadi, Riva Yudha Abriyant, Dedi Suntoro, Faridha Faridha, I. Reksowardojo","doi":"10.18331/brj2023.10.3.2","DOIUrl":"https://doi.org/10.18331/brj2023.10.3.2","url":null,"abstract":"This research focused on evaluating the technical viability of using biodiesel with a blending ratio of 40% v/v, which is expected to be implemented soon in Indonesia. Two kinds of biodiesel blends were prepared, a blend of 60% diesel fuel and 40% biodiesel (B40) and a blend of 60% diesel fuel, 30% biodiesel, and 10% hydrogenated vegetable oil (HVO) (B30D10). The fuels were tested on EuroII vehicles without any engine modifications through a 50,000 km endurance road test. Laboratory tests were also performed at certain traveled distances to evaluate various engine parameters, including power, fuel economy, exhaust emissions, and used engine oil properties. Engine components were inspected upon the completion of the road test. Cold-start ability was also examined to confirm the suitability of the investigated biofuels at low-temperature operating conditions in Indonesia. The road test results showed that vehicles fuelled with B40 and B30D10 could reach a distance of 50,000 km without encountering any technical issues. The laboratory evaluation during the road test indicated that B30D10 had a higher power and fuel economy than B40, with a maximum difference of 2%. Furthermore, B30D10 emitted lower CO, HC, and PM emissions than B40 throughout the distance traveled, with maximum differences of 11.4%, 14.7%, and 22.6%, respectively, but led to 15% higher NOx. Engine component inspection and used engine oil analysis confirmed the fulfillment of the manufacturer's recommendations for both B40 and B30D10. Finally, B40 and B30D10 were suitable for operating at low ambient temperatures in Indonesia, confirming them as practical options to be implemented in the nationwide 40% biodiesel blend fuel.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":" ","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46168722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biobased fuels, chemicals, and materials can replace fossil fuel products and mitigate climate change. Sugarcane mills have the potential to produce a wider range of biobased chemicals in a similar approach to bioethanol production, including adipic acid. Multiple alternative pathways for converting simple sugars into adipic acid have been described, with the potential for integration into a sugar mill. The economics and expected greenhouse gas emissions reductions compared to fossil-based adipic acid were investigated in the present study to identify preferred pathways for implementation in sugarcane biorefineries. Nine biobased pathways for adipic acid production were screened for technical performances, resulting in the selection of four preferred options for rigorous comparison, i.e., direct microbial conversion of sugars, and production via cis,cis-muconic acid, glucaric acid, and glycerol as intermediate, obtained from sugars. The minimum selling prices of adipic acid for an attractive return on investment were determined for these pathways, using either A-molasses or a combination of A-molasses and pretreated sugarcane lignocelluloses in biorefineries designed to be energy-self-sufficient. Adipic acid production from A-molasses via cis,cis-muconic acid was the best overall performing scenario with the lowest minimum selling price of USD 2,538/Mt and lowered greenhouse gas emissions (2,325 g CO2 eq/kg wet) compared to fossil-based adipic acid production. The scenarios with combined A-molasses and lignocellulosic feedstock had increased minimum selling prices by 29 to 101% compared to adipic acid production from A molasses via cis,cis-muconic acid.
生物基燃料、化学品和材料可以取代化石燃料产品，减缓气候变化。甘蔗工厂有潜力以类似于生物乙醇生产的方式生产更广泛的生物基化学品，包括己二酸。已经描述了将单糖转化为己二酸的多种替代途径，具有整合到糖厂的潜力。与化石基己二酸相比，本研究调查了经济性和预期的温室气体减排，以确定在甘蔗生物炼制中实施的首选途径。对九种生物基己二酸生产途径进行了技术性能筛选，最终选择了四种首选途径进行严格比较，即直接微生物转化糖，以及通过从糖中获得的顺式、顺式粘膜酸、葡萄糖酸和甘油作为中间体生产己二酸。对于这些途径，确定了具有吸引力的投资回报的己二酸的最低销售价格，在生物精炼厂中使用a -糖蜜或a -糖蜜和预处理甘蔗木质纤维素的组合，以实现能源自给自足。通过顺式、顺式黏液酸从a -糖蜜中生产己二酸是整体表现最好的方案，最低销售价格为2538美元/吨，与化石基己二酸生产相比，温室气体排放量(2325 g CO2当量/千克湿)降低。与A糖蜜通过顺式、顺式黏液酸生产己二酸相比，A糖蜜和木质纤维素混合原料的最低销售价格提高了29%至101%。
{"title":"A critical review of multiple alternative pathways for the production of a high-value bioproduct from sugarcane mill byproducts: the case of adipic acid","authors":"Yakim Cronjé, S. Farzad, M. Mandegari, J. Görgens","doi":"10.18331/brj2023.10.3.5","DOIUrl":"https://doi.org/10.18331/brj2023.10.3.5","url":null,"abstract":"Biobased fuels, chemicals, and materials can replace fossil fuel products and mitigate climate change. Sugarcane mills have the potential to produce a wider range of biobased chemicals in a similar approach to bioethanol production, including adipic acid. Multiple alternative pathways for converting simple sugars into adipic acid have been described, with the potential for integration into a sugar mill. The economics and expected greenhouse gas emissions reductions compared to fossil-based adipic acid were investigated in the present study to identify preferred pathways for implementation in sugarcane biorefineries. Nine biobased pathways for adipic acid production were screened for technical performances, resulting in the selection of four preferred options for rigorous comparison, i.e., direct microbial conversion of sugars, and production via cis,cis-muconic acid, glucaric acid, and glycerol as intermediate, obtained from sugars. The minimum selling prices of adipic acid for an attractive return on investment were determined for these pathways, using either A-molasses or a combination of A-molasses and pretreated sugarcane lignocelluloses in biorefineries designed to be energy-self-sufficient. Adipic acid production from A-molasses via cis,cis-muconic acid was the best overall performing scenario with the lowest minimum selling price of USD 2,538/Mt and lowered greenhouse gas emissions (2,325 g CO2 eq/kg wet) compared to fossil-based adipic acid production. The scenarios with combined A-molasses and lignocellulosic feedstock had increased minimum selling prices by 29 to 101% compared to adipic acid production from A molasses via cis,cis-muconic acid.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":" ","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44038922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiangmeng Chen, Homa Hosseinzadeh-Bandbafha, Hamed Kazemi, Shariat Panahi, M. Dehhaghi, Y. Orooji, Hossein Shahbeik, Omid Mahian, Hassan Karimi-Maleh, Alawi Sulaiman, Changtong Mei, M. Kiehbadroudinezhad, A. Nizami, Gilles G. Guillemin, Su Shiung Lam, Wanxi Peng, Ki-Hyun Kim, M. Aghbashlo, M. Tabatabaei, Tabatabaei M. Nanomaterials
Sustainable socio-economic development largely depends on the sustainability of the energy supply from economic, environmental, and public health perspectives. Fossil fuel combustion only meets the first element of this equation and is hence rendered unsustainable. Biofuels are advantageous from a public health perspective, but their environmental and economic sustainability might be questioned considering the conflicts surrounding their feedstocks, including land use change and fuel vs. food conflict. Therefore, it is imperative to put more effort into addressing the downsides of biofuel production using advanced technologies, such as nanotechnology. In light of that, this review strives to scrutinize the latest developments in the application of nanotechnology in producing biodiesel, a promising alternative to fossil diesel with proven environmental and health benefits. The main focus is placed on nanotechnology applications in the feedstock production stage. First, the latest findings concerning the application of nanomaterials as nanofertilizers and nanopesticides to improve the performance of oil crops are presented and critically discussed. Then, the most promising results reported recently on applying nanotechnology to boost biomass and oil production by microalgae and facilitating microalgae harvesting are reviewed and mechanistically explained. Finally, the promises held by nanomaterials to enhance animal fat production in livestock, poultry, and aquaculture systems are elaborated. Despite the favorable features of using nanotechnology in biodiesel feedstock production, the presence of nanoparticles in living systems is also associated with important health and environmental challenges, which are critically covered and discussed in this work.
{"title":"Nanomaterials and their role in advancing biodiesel feedstock production: A comprehensive review","authors":"Xiangmeng Chen, Homa Hosseinzadeh-Bandbafha, Hamed Kazemi, Shariat Panahi, M. Dehhaghi, Y. Orooji, Hossein Shahbeik, Omid Mahian, Hassan Karimi-Maleh, Alawi Sulaiman, Changtong Mei, M. Kiehbadroudinezhad, A. Nizami, Gilles G. Guillemin, Su Shiung Lam, Wanxi Peng, Ki-Hyun Kim, M. Aghbashlo, M. Tabatabaei, Tabatabaei M. Nanomaterials","doi":"10.18331/brj2023.10.3.4","DOIUrl":"https://doi.org/10.18331/brj2023.10.3.4","url":null,"abstract":"Sustainable socio-economic development largely depends on the sustainability of the energy supply from economic, environmental, and public health perspectives. Fossil fuel combustion only meets the first element of this equation and is hence rendered unsustainable. Biofuels are advantageous from a public health perspective, but their environmental and economic sustainability might be questioned considering the conflicts surrounding their feedstocks, including land use change and fuel vs. food conflict. Therefore, it is imperative to put more effort into addressing the downsides of biofuel production using advanced technologies, such as nanotechnology. In light of that, this review strives to scrutinize the latest developments in the application of nanotechnology in producing biodiesel, a promising alternative to fossil diesel with proven environmental and health benefits. The main focus is placed on nanotechnology applications in the feedstock production stage. First, the latest findings concerning the application of nanomaterials as nanofertilizers and nanopesticides to improve the performance of oil crops are presented and critically discussed. Then, the most promising results reported recently on applying nanotechnology to boost biomass and oil production by microalgae and facilitating microalgae harvesting are reviewed and mechanistically explained. Finally, the promises held by nanomaterials to enhance animal fat production in livestock, poultry, and aquaculture systems are elaborated. Despite the favorable features of using nanotechnology in biodiesel feedstock production, the presence of nanoparticles in living systems is also associated with important health and environmental challenges, which are critically covered and discussed in this work.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":" ","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48766235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Avinash Alagumalai, Balaji Devarajan, Huan-zhi Song, S. Wongwises, R. Ledesma-Amaro, O. Mahian, M. Sheremet, E. Lichtfouse
Biohydrogen is emerging as a promising carbon-neutral and sustainable energy carrier with high energy yield to replace conventional fossil fuels. However, biohydrogen commercial uptake is mainly hindered by the supply side. As a result, various operating parameters must be optimized to realize biohydrogen commercial uptake on a large-scale. Recently, machine learning algorithms have demonstrated the ability to handle large amounts of data while requiring less in-depth knowledge of the system and being capable of adapting to evolving circumstances. This review critically reviews the role of machine learning in categorizing and predicting data related to biohydrogen production. The accuracy and potential of different machine learning algorithms are reported. Also, the practical implications of machine learning models to realize biohydrogen uptake by the transportation sector are discussed. The review indicates that machine learning algorithms can successfully model non-linear and complex interactions between operational and performance parameters in biohydrogen production. Additionally, machine learning algorithms can help researchers identify the most efficient methods for producing biohydrogen, leading to a more sustainable and cost-effective energy source.
{"title":"Machine learning in biohydrogen production: a review","authors":"Avinash Alagumalai, Balaji Devarajan, Huan-zhi Song, S. Wongwises, R. Ledesma-Amaro, O. Mahian, M. Sheremet, E. Lichtfouse","doi":"10.18331/brj2023.10.2.4","DOIUrl":"https://doi.org/10.18331/brj2023.10.2.4","url":null,"abstract":"Biohydrogen is emerging as a promising carbon-neutral and sustainable energy carrier with high energy yield to replace conventional fossil fuels. However, biohydrogen commercial uptake is mainly hindered by the supply side. As a result, various operating parameters must be optimized to realize biohydrogen commercial uptake on a large-scale. Recently, machine learning algorithms have demonstrated the ability to handle large amounts of data while requiring less in-depth knowledge of the system and being capable of adapting to evolving circumstances. This review critically reviews the role of machine learning in categorizing and predicting data related to biohydrogen production. The accuracy and potential of different machine learning algorithms are reported. Also, the practical implications of machine learning models to realize biohydrogen uptake by the transportation sector are discussed. The review indicates that machine learning algorithms can successfully model non-linear and complex interactions between operational and performance parameters in biohydrogen production. Additionally, machine learning algorithms can help researchers identify the most efficient methods for producing biohydrogen, leading to a more sustainable and cost-effective energy source.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":" ","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48476161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper builds a quantitative thermodynamic model for the microbial hydrolysis process (MHP, which uses Caldicellulosiruptor bescii at 75°C for pre-digestion) for producing biogas from a 5-10% aqueous suspension of dairy manure (naturally buffered near pH 7.8 by ammonium bicarbonate) by anaerobic digestion with a mix of acetoclastic and syntrophic methanogenesis. Standard Gibbs energy changes were calculated for the major reactions in pre-digestion, for reactions producing H2, acetate, and CO2 in the digester, and for methanogenesis reactions in the digester. The available data limit the study to analyzing reactions in the digester to reactions of short-chain volatile fatty acids anions. Results are presented as curves of ΔrxnG (Gibbs energy change) vs. acetate concentration. The H2(aq) concentration must be above 1.2×10-9 M to get significant syntrophic methanogenesis, i.e., for ΔrxnG to be negative. The results show syntrophic methanogenesis of propionate, butyrate, and valerate slows as acetate concentration increases because hydrogen production also decreases, and consequently, biogas production from syntrophic methanogenesis slows as acetate increases. Bicarbonate also inhibits both acetoclastic and syntrophic methanogenesis but is necessary to prevent acidification (souring) of the digester. At identical steady-state conditions, acetoclastic methanogenesis runs about 1.4 times faster than syntrophic methanogenesis. Because syntrophic methanogenesis produces acetate catabolized by acetoclastic methanogens, both types of methanogens are necessary to maximize biogas production. The culture in the digester is predicted to evolve to optimize the ratio of acetoclastic methanogens to syntrophic methanogens, a condition signaled by a constant, low acetate concentration in the digester effluent. Obtaining volatile solids reduction as high as 75% with MHP requires a feedstock with less than 25% lignin and a culture of acetoclastic methanogens and syntrophic methanogens and their symbiotic bacteria.
{"title":"Thermodynamic method for analyzing and optimizing pretreatment/anaerobic digestion systems","authors":"L. Hansen","doi":"10.18331/brj2023.10.2.2","DOIUrl":"https://doi.org/10.18331/brj2023.10.2.2","url":null,"abstract":"This paper builds a quantitative thermodynamic model for the microbial hydrolysis process (MHP, which uses Caldicellulosiruptor bescii at 75°C for pre-digestion) for producing biogas from a 5-10% aqueous suspension of dairy manure (naturally buffered near pH 7.8 by ammonium bicarbonate) by anaerobic digestion with a mix of acetoclastic and syntrophic methanogenesis. Standard Gibbs energy changes were calculated for the major reactions in pre-digestion, for reactions producing H2, acetate, and CO2 in the digester, and for methanogenesis reactions in the digester. The available data limit the study to analyzing reactions in the digester to reactions of short-chain volatile fatty acids anions. Results are presented as curves of ΔrxnG (Gibbs energy change) vs. acetate concentration. The H2(aq) concentration must be above 1.2×10-9 M to get significant syntrophic methanogenesis, i.e., for ΔrxnG to be negative. The results show syntrophic methanogenesis of propionate, butyrate, and valerate slows as acetate concentration increases because hydrogen production also decreases, and consequently, biogas production from syntrophic methanogenesis slows as acetate increases. Bicarbonate also inhibits both acetoclastic and syntrophic methanogenesis but is necessary to prevent acidification (souring) of the digester. At identical steady-state conditions, acetoclastic methanogenesis runs about 1.4 times faster than syntrophic methanogenesis. Because syntrophic methanogenesis produces acetate catabolized by acetoclastic methanogens, both types of methanogens are necessary to maximize biogas production. The culture in the digester is predicted to evolve to optimize the ratio of acetoclastic methanogens to syntrophic methanogens, a condition signaled by a constant, low acetate concentration in the digester effluent. Obtaining volatile solids reduction as high as 75% with MHP requires a feedstock with less than 25% lignin and a culture of acetoclastic methanogens and syntrophic methanogens and their symbiotic bacteria.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":" ","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47062008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chonlatep Usaku, A. Yahya, Phannipha Daisuk, A. Shotipruk
This study recovered γ-oryzanol from rice bran acid oil (RBAO), following an initial enzymatic esterification/transesterification to selectively convert its glyceride impurities into fatty acid ethyl esters (FAEEs) or biodiesel. γ-oryzanol was then deprotonated and separated from the biodiesel into the resulting aqueous phase via acid-base extraction. Herein, we determine the effects of varying reaction conditions, i.e., ethanol:RBAO molar ratio, temperature, reaction time, enzyme loading, and agitation speed, on the degrees of glyceride removal, γ-oryzanol loss, free fatty acid (FFA) remaining, and biodiesel content. Up to 100% glyceride removal was achieved with a relatively high biodiesel yield (84%) and γ-oryzanol loss as low as 26% under our most suitable reaction conditions (5:1 ethanol:RBAO molar ratio, 40 °C, 24 h reaction time, 10%wt enzyme loading, 200 rpm agitation). Furthermore, of the remaining oryzanol, up to 94% was recovered by the acid-base extraction with 2-4 M ethanolic NaOH solution. Our results suggest that a combination of enzymatic esterification/transesterification with subsequent acid-base extraction offers an efficient alternative approach to the simultaneous production of biodiesel and γ-oryzanol recovery from low-cost RBAO. Based on our analysis of techno-economic and environmental sustainability, integration of the present method into a rice bran oil refinery would make the process profitable, with the minimum use of toxic chemicals and energy.
{"title":"Enzymatic esterification/transesterification of rice bran acid oil for subsequent γ-oryzanol recovery","authors":"Chonlatep Usaku, A. Yahya, Phannipha Daisuk, A. Shotipruk","doi":"10.18331/brj2023.10.2.3","DOIUrl":"https://doi.org/10.18331/brj2023.10.2.3","url":null,"abstract":"This study recovered γ-oryzanol from rice bran acid oil (RBAO), following an initial enzymatic esterification/transesterification to selectively convert its glyceride impurities into fatty acid ethyl esters (FAEEs) or biodiesel. γ-oryzanol was then deprotonated and separated from the biodiesel into the resulting aqueous phase via acid-base extraction. Herein, we determine the effects of varying reaction conditions, i.e., ethanol:RBAO molar ratio, temperature, reaction time, enzyme loading, and agitation speed, on the degrees of glyceride removal, γ-oryzanol loss, free fatty acid (FFA) remaining, and biodiesel content. Up to 100% glyceride removal was achieved with a relatively high biodiesel yield (84%) and γ-oryzanol loss as low as 26% under our most suitable reaction conditions (5:1 ethanol:RBAO molar ratio, 40 °C, 24 h reaction time, 10%wt enzyme loading, 200 rpm agitation). Furthermore, of the remaining oryzanol, up to 94% was recovered by the acid-base extraction with 2-4 M ethanolic NaOH solution. Our results suggest that a combination of enzymatic esterification/transesterification with subsequent acid-base extraction offers an efficient alternative approach to the simultaneous production of biodiesel and γ-oryzanol recovery from low-cost RBAO. Based on our analysis of techno-economic and environmental sustainability, integration of the present method into a rice bran oil refinery would make the process profitable, with the minimum use of toxic chemicals and energy.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":" ","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42103980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, machine learning (ML) applications in lignocellulosic bioethanol production were reviewed. First, the pretreatment-hydrolysis-fermentation route, the most commonly studied alternative, was summarized. Next, a bibliometric analysis was performed to identify the current trends in the field; it was found that ML applications in the field are not only increasing but also expanding their relative share in publications, with bioethanol seeming to be the most frequently researched topic while biochar and biogas are also receiving increased attention in recent years. Then, the implementation of ML for lignocellulosic bioethanol production via this route was reviewed in depth. It was observed that artificial neural network (ANN) is the most commonly used algorithm (appeared in almost 90% of articles), followed by response surface methodology (RSM) (in about 25% of articles) and random forest (RF) (in about 10% of articles). Bioethanol concentration is the most common output variable in the fermentation step, while fermentable sugar and glucose concentration are studied most in hydrolysis. The datasets are usually small, while the fitnesses of the models (R2) are usually high in the papers reviewed. Finally, a perspective for future studies, mostly considering improving data availability, was provided.
{"title":"A critical review of machine learning for lignocellulosic ethanol production via fermentation route","authors":"Ahmet Çoşgun, M. E. Günay, R. Yıldırım","doi":"10.18331/brj2023.10.2.5","DOIUrl":"https://doi.org/10.18331/brj2023.10.2.5","url":null,"abstract":"In this work, machine learning (ML) applications in lignocellulosic bioethanol production were reviewed. First, the pretreatment-hydrolysis-fermentation route, the most commonly studied alternative, was summarized. Next, a bibliometric analysis was performed to identify the current trends in the field; it was found that ML applications in the field are not only increasing but also expanding their relative share in publications, with bioethanol seeming to be the most frequently researched topic while biochar and biogas are also receiving increased attention in recent years. Then, the implementation of ML for lignocellulosic bioethanol production via this route was reviewed in depth. It was observed that artificial neural network (ANN) is the most commonly used algorithm (appeared in almost 90% of articles), followed by response surface methodology (RSM) (in about 25% of articles) and random forest (RF) (in about 10% of articles). Bioethanol concentration is the most common output variable in the fermentation step, while fermentable sugar and glucose concentration are studied most in hydrolysis. The datasets are usually small, while the fitnesses of the models (R2) are usually high in the papers reviewed. Finally, a perspective for future studies, mostly considering improving data availability, was provided.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":"1 1","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41361056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adequate waste management is essential not only to ensure healthy living conditions but also to mitigate climate change. Accordingly, the research on developing strategies to boost the circularity of waste management systems is ongoing. In this context, two waste streams are concurrently managed to recover energy and materials in the present study. Specifically, real leachate collected from a full-scale mature landfill site was preliminarily treated through active filtration to remove inhibitory substances partially and then tested, at the laboratory scale, as a nutrient solution for semi-continuous anaerobic digestion of a carbonaceous substrate represented by market waste. The results demonstrate that, at an organic loading rate of 1.0 gVS∙L-1∙d-1, the process was impossible without using the nutrient solution, while the nitrogen present in the pretreated leachate could balance the carbon content of the market waste and provide the system with the necessary buffering capacity, ensuring process stability. The average methane yield (approximately 0.29 NL∙gVS-1) was satisfactory and consistent with the literature. Despite the increases in both the organic loading rate (up to 1.5 gVS∙L-1∙d-1) and volume of added pretreated leachate (up to 100% of the dilution medium), the process remained stable with a slightly lower methane yield of 0.21 NL∙gVS-1, thanks to nitrogen supplementation. The potential use of produced methane as a renewable energy source and residual digestate as fertilizer would close the loop of managing these waste streams.
{"title":"Boosting the circularity of waste management: pretreated mature landfill leachate enhances the anaerobic digestion of market waste","authors":"F. Fazzino, Altea Pedullà, P. Calabrò","doi":"10.18331/brj2023.10.1.2","DOIUrl":"https://doi.org/10.18331/brj2023.10.1.2","url":null,"abstract":"Adequate waste management is essential not only to ensure healthy living conditions but also to mitigate climate change. Accordingly, the research on developing strategies to boost the circularity of waste management systems is ongoing. In this context, two waste streams are concurrently managed to recover energy and materials in the present study. Specifically, real leachate collected from a full-scale mature landfill site was preliminarily treated through active filtration to remove inhibitory substances partially and then tested, at the laboratory scale, as a nutrient solution for semi-continuous anaerobic digestion of a carbonaceous substrate represented by market waste. The results demonstrate that, at an organic loading rate of 1.0 gVS∙L-1∙d-1, the process was impossible without using the nutrient solution, while the nitrogen present in the pretreated leachate could balance the carbon content of the market waste and provide the system with the necessary buffering capacity, ensuring process stability. The average methane yield (approximately 0.29 NL∙gVS-1) was satisfactory and consistent with the literature. Despite the increases in both the organic loading rate (up to 1.5 gVS∙L-1∙d-1) and volume of added pretreated leachate (up to 100% of the dilution medium), the process remained stable with a slightly lower methane yield of 0.21 NL∙gVS-1, thanks to nitrogen supplementation. The potential use of produced methane as a renewable energy source and residual digestate as fertilizer would close the loop of managing these waste streams.","PeriodicalId":46938,"journal":{"name":"Biofuel Research Journal-BRJ","volume":" ","pages":""},"PeriodicalIF":13.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47291384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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