Pub Date : 2022-11-29DOI: 10.3389/fceng.2022.1066027
Indira Chimanlal, L. Nthunya, C. Quist-Jensen, H. Richards
Membrane distillation crystallization (MDC) is an emerging technology envisaged to manage challenges affecting the desalination industry. This technology can sustainably treat concentrated solutions of produced water and industrially discharged saline wastewater. Simultaneous recovery of clean water and minerals is achieved through the integration of crystallization to membrane distillation (MD). MDC has received vast research interest because of its potential to treat hypersaline solutions. However, MDC still faces challenges in harnessing its industrial applications. Technically, MDC is affected by fouling/scaling and wetting thereby hindering practical application at the industrial level. This study reviews the occurrence of membrane fouling and wetting experienced with MDC. Additionally, existing developments carried out to address these challenges are critically reviewed. Finally, prospects suggesting the sustainability of this technology are highlighted.
{"title":"Membrane distillation crystallization for water and mineral recovery: The occurrence of fouling and its control during wastewater treatment","authors":"Indira Chimanlal, L. Nthunya, C. Quist-Jensen, H. Richards","doi":"10.3389/fceng.2022.1066027","DOIUrl":"https://doi.org/10.3389/fceng.2022.1066027","url":null,"abstract":"Membrane distillation crystallization (MDC) is an emerging technology envisaged to manage challenges affecting the desalination industry. This technology can sustainably treat concentrated solutions of produced water and industrially discharged saline wastewater. Simultaneous recovery of clean water and minerals is achieved through the integration of crystallization to membrane distillation (MD). MDC has received vast research interest because of its potential to treat hypersaline solutions. However, MDC still faces challenges in harnessing its industrial applications. Technically, MDC is affected by fouling/scaling and wetting thereby hindering practical application at the industrial level. This study reviews the occurrence of membrane fouling and wetting experienced with MDC. Additionally, existing developments carried out to address these challenges are critically reviewed. Finally, prospects suggesting the sustainability of this technology are highlighted.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45889717","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}
Pub Date : 2022-11-21DOI: 10.3389/fceng.2022.1004240
Daehwan Kim, Anqi Ji, Armoni L. Jackson, Bailee Brown, Youngmi Kim, S. Kim, C. Laufer, Drew Ferrier, C. Yoo
The one-pot biomass conversion process is a promising strategy to minimize potential product loss and reduce processing costs. However, this strategy has technical limitations due to the inhibitory effects of biomass components like lignin as well as the generated inhibitors (e.g., furans, phenols) during biomass processing. In this study, the inhibitory effects of liquid hydrolysates formed by hydrothermal pretreatment of soybean straw with either sodium hydroxide (NaOH) or hydrogen peroxide (H2O2) on cellulolytic enzyme activity were investigated. Hydrothermal pretreatment of soybean straw (10% w/v) was carried out with either sodium hydroxide (1% v/v) or hydrogen peroxide (1% v/v) at 121°C for 60 min to evaluate the effect of water-soluble inhibitors released from soybean pretreatment on cellulolytic enzyme activity. The fraction of cellulose in pretreated solids (1% w/v glucan) was enzymatically hydrolyzed for 72 h with 45 IU/g glucan (corresponding to 25 mg enzyme protein/g glucan) in the presence of either buffer or liquid hydrolysate generated from the pretreatments. Hydrolysis of NaOH and H2O2 pretreated solids resulted in 57% and 39% of glucose yields in buffer, respectively. In the presence of the liquid hydrolysates, NaOH and H2O2 pretreated biomass showed 20% and 30% glucose yield, respectively, indicating the enzyme suppression by inhibitors in the liquid hydrolysates. Of the enzyme activities in hydrolysates tested, NaOH hydrolysate showed a higher inhibitory effect on enzyme activities (mainly β-glucosidase) compared to H2O2 liquid, where enzyme deactivation has a first-order correlation and the manner in which the vacuum-filtered inhibitors were generated from pretreated soybean straw.
{"title":"Inhibition of cellulase activity by liquid hydrolysates from hydrothermally pretreated soybean straw","authors":"Daehwan Kim, Anqi Ji, Armoni L. Jackson, Bailee Brown, Youngmi Kim, S. Kim, C. Laufer, Drew Ferrier, C. Yoo","doi":"10.3389/fceng.2022.1004240","DOIUrl":"https://doi.org/10.3389/fceng.2022.1004240","url":null,"abstract":"The one-pot biomass conversion process is a promising strategy to minimize potential product loss and reduce processing costs. However, this strategy has technical limitations due to the inhibitory effects of biomass components like lignin as well as the generated inhibitors (e.g., furans, phenols) during biomass processing. In this study, the inhibitory effects of liquid hydrolysates formed by hydrothermal pretreatment of soybean straw with either sodium hydroxide (NaOH) or hydrogen peroxide (H2O2) on cellulolytic enzyme activity were investigated. Hydrothermal pretreatment of soybean straw (10% w/v) was carried out with either sodium hydroxide (1% v/v) or hydrogen peroxide (1% v/v) at 121°C for 60 min to evaluate the effect of water-soluble inhibitors released from soybean pretreatment on cellulolytic enzyme activity. The fraction of cellulose in pretreated solids (1% w/v glucan) was enzymatically hydrolyzed for 72 h with 45 IU/g glucan (corresponding to 25 mg enzyme protein/g glucan) in the presence of either buffer or liquid hydrolysate generated from the pretreatments. Hydrolysis of NaOH and H2O2 pretreated solids resulted in 57% and 39% of glucose yields in buffer, respectively. In the presence of the liquid hydrolysates, NaOH and H2O2 pretreated biomass showed 20% and 30% glucose yield, respectively, indicating the enzyme suppression by inhibitors in the liquid hydrolysates. Of the enzyme activities in hydrolysates tested, NaOH hydrolysate showed a higher inhibitory effect on enzyme activities (mainly β-glucosidase) compared to H2O2 liquid, where enzyme deactivation has a first-order correlation and the manner in which the vacuum-filtered inhibitors were generated from pretreated soybean straw.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43665347","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}
Pub Date : 2022-11-18DOI: 10.3389/fceng.2022.1046019
Srishti, Khushi Khandelwal, Aditya Kumar, A. Sinhamahapatra
Solar water interfacial evaporation (SWIE) has attracted much attention for harvesting clean water. Over the last few decades, researchers have developed an innovative photo-thermal material for high-performance solar water interfacial evaporation. For higher evaporation performance, TiO2-based materials gain attention as a promising photo-thermal material due to their light absorption capacity. This study compared conceptual designs of TiO2-based materials for SWIE. Structural design and engineering strategies for improving evaporation rates and higher thermal conversion efficiency were reviewed. In addition, the material’s thermal stability and heat management were analyzed. This review provides an overview of the current advances in photo-thermal TiO2 materials to motivate research and translation efforts from the laboratory to large-scale solar water clean water production. Additional benefits of TiO2 materials on solar water interfacial evaporation should be investigated beyond containers to solve interconnected water, environmental, and energy progression.
{"title":"Progress on TiO2-based materials for solar water interfacial evaporation","authors":"Srishti, Khushi Khandelwal, Aditya Kumar, A. Sinhamahapatra","doi":"10.3389/fceng.2022.1046019","DOIUrl":"https://doi.org/10.3389/fceng.2022.1046019","url":null,"abstract":"Solar water interfacial evaporation (SWIE) has attracted much attention for harvesting clean water. Over the last few decades, researchers have developed an innovative photo-thermal material for high-performance solar water interfacial evaporation. For higher evaporation performance, TiO2-based materials gain attention as a promising photo-thermal material due to their light absorption capacity. This study compared conceptual designs of TiO2-based materials for SWIE. Structural design and engineering strategies for improving evaporation rates and higher thermal conversion efficiency were reviewed. In addition, the material’s thermal stability and heat management were analyzed. This review provides an overview of the current advances in photo-thermal TiO2 materials to motivate research and translation efforts from the laboratory to large-scale solar water clean water production. Additional benefits of TiO2 materials on solar water interfacial evaporation should be investigated beyond containers to solve interconnected water, environmental, and energy progression.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48781027","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}
Pub Date : 2022-11-18DOI: 10.3389/fceng.2022.1064221
Jangwon Lee, Ankur Kumar, Jesus Flores-Cerrillo, Jin Wang, Q. He
Pressure swing adsorption (PSA) is a widely used technology to separate a gas product from impurities in a variety of fields. Due to the complexity of PSA operations, process and instrument faults can occur at different parts and/or steps of the process. Thus, effective process monitoring is critical for ensuring efficient and safe operations of PSA systems. However, multi-bed PSA processes present several major challenges to process monitoring. First, a PSA process is operated in a periodic or cyclic fashion and never reaches a steady state; Second, the duration of different operation cycles is dynamically controlled in response to various disturbances, which results in a wide range of normal operation trajectories. Third, there is limited data for process monitoring, and bed pressure is usually the only measured variable for process monitoring. These key characteristics of the PSA operation make process monitoring, especially early fault detection, significantly more challenging than that for a continuous process operated at a steady state. To address these challenges, we propose a feature-based statistical process monitoring (SPM) framework for PSA processes, namely feature space monitoring (FSM). Through feature engineering and feature selection, we show that FSM can naturally handle the key challenges in PSA process monitoring and achieve early detection of subtle faults from a wide range of normal operating conditions. The performance of FSM is compared to the conventional SPM methods using both simulated and real faults from an industrial PSA process. The results demonstrate FSM’s superior performance in fault detection and fault diagnosis compared to the traditional SPM methods. In particular, the robust monitoring performance from FSM is achieved without any data preprocessing, trajectory alignment or synchronization required by the conventional SPM methods.
{"title":"Feature-based statistical process monitoring for pressure swing adsorption processes","authors":"Jangwon Lee, Ankur Kumar, Jesus Flores-Cerrillo, Jin Wang, Q. He","doi":"10.3389/fceng.2022.1064221","DOIUrl":"https://doi.org/10.3389/fceng.2022.1064221","url":null,"abstract":"Pressure swing adsorption (PSA) is a widely used technology to separate a gas product from impurities in a variety of fields. Due to the complexity of PSA operations, process and instrument faults can occur at different parts and/or steps of the process. Thus, effective process monitoring is critical for ensuring efficient and safe operations of PSA systems. However, multi-bed PSA processes present several major challenges to process monitoring. First, a PSA process is operated in a periodic or cyclic fashion and never reaches a steady state; Second, the duration of different operation cycles is dynamically controlled in response to various disturbances, which results in a wide range of normal operation trajectories. Third, there is limited data for process monitoring, and bed pressure is usually the only measured variable for process monitoring. These key characteristics of the PSA operation make process monitoring, especially early fault detection, significantly more challenging than that for a continuous process operated at a steady state. To address these challenges, we propose a feature-based statistical process monitoring (SPM) framework for PSA processes, namely feature space monitoring (FSM). Through feature engineering and feature selection, we show that FSM can naturally handle the key challenges in PSA process monitoring and achieve early detection of subtle faults from a wide range of normal operating conditions. The performance of FSM is compared to the conventional SPM methods using both simulated and real faults from an industrial PSA process. The results demonstrate FSM’s superior performance in fault detection and fault diagnosis compared to the traditional SPM methods. In particular, the robust monitoring performance from FSM is achieved without any data preprocessing, trajectory alignment or synchronization required by the conventional SPM methods.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46481345","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}
Pub Date : 2022-11-15DOI: 10.3389/fceng.2022.1054124
T. Salmi, P. Tolvanen, K. Eränen, J. Wärnå
Residence time distribution (RTD) has a very high impact on the performance of a chemical reactor. The development of new reactor and catalyst structures has increased the importance of deep knowledge in theories of RTDs and good experimental practice in measuring RTDs in real systems. Therefore, RTD studies are included in chemical engineering education all over the world. This work demonstrates how RTDs can be measured by using urban pieces of art. Impulse experiments with an inert tracer (NaCl) were conducted in a marvelous modern artwork, ‘Flow of time’ in Turku/Åbo. The results were successfully interpreted with the classical laminar flow model. The application of the methodology in historical university cities is suggested.
{"title":"Experimental determination and mathematical modelling of residence time distributions by using pieces of urban art","authors":"T. Salmi, P. Tolvanen, K. Eränen, J. Wärnå","doi":"10.3389/fceng.2022.1054124","DOIUrl":"https://doi.org/10.3389/fceng.2022.1054124","url":null,"abstract":"Residence time distribution (RTD) has a very high impact on the performance of a chemical reactor. The development of new reactor and catalyst structures has increased the importance of deep knowledge in theories of RTDs and good experimental practice in measuring RTDs in real systems. Therefore, RTD studies are included in chemical engineering education all over the world. This work demonstrates how RTDs can be measured by using urban pieces of art. Impulse experiments with an inert tracer (NaCl) were conducted in a marvelous modern artwork, ‘Flow of time’ in Turku/Åbo. The results were successfully interpreted with the classical laminar flow model. The application of the methodology in historical university cities is suggested.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47569456","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}
Pub Date : 2022-11-15DOI: 10.3389/fceng.2022.1027167
C. Charalambous, Shanshan Xu, Sheng Ding, Sarayute Chansai, E. Asuquo, Antonio Torres Lopez, Christopher M. A. Parlett, J. Gilmour, Arthur A. Garforth, C. Hardacre
The catalytic conversion of CO2 to CH4 and CO over nickel particles supported on layered-double hydroxide (MgAl) with different metal promoters was investigated under non-thermal plasma (NTP) conditions. It has been shown that lanthanum-promoted Ni catalysts significantly enhanced the CO2 conversion in comparison to the 10Ni/MgAl catalyst (33.4% vs. 89.3%). In comparison, for the potassium-promoted catalysts, CO2 conversion is similar to that of 10Ni/MgAl but the CO selectivity increased significantly (35.7% vs. 62.0%). The introduction of La and K to Ni catalysts increased the Ni dispersion and improved the reducibility of Ni species, thus affecting CO2 conversion and product selectivity. In situ DRIFTS showed similar reaction pathways for La- and K- promoted catalysts with Ni catalysts. However, the La and K promoters significantly improved the formation of formate species on the Ni surface, facilitating CO2 conversion to useful products.
{"title":"Non-thermal plasma activated CO2 hydrogenation over K- and La- promoted layered-double hydroxide supported Ni catalysts","authors":"C. Charalambous, Shanshan Xu, Sheng Ding, Sarayute Chansai, E. Asuquo, Antonio Torres Lopez, Christopher M. A. Parlett, J. Gilmour, Arthur A. Garforth, C. Hardacre","doi":"10.3389/fceng.2022.1027167","DOIUrl":"https://doi.org/10.3389/fceng.2022.1027167","url":null,"abstract":"The catalytic conversion of CO2 to CH4 and CO over nickel particles supported on layered-double hydroxide (MgAl) with different metal promoters was investigated under non-thermal plasma (NTP) conditions. It has been shown that lanthanum-promoted Ni catalysts significantly enhanced the CO2 conversion in comparison to the 10Ni/MgAl catalyst (33.4% vs. 89.3%). In comparison, for the potassium-promoted catalysts, CO2 conversion is similar to that of 10Ni/MgAl but the CO selectivity increased significantly (35.7% vs. 62.0%). The introduction of La and K to Ni catalysts increased the Ni dispersion and improved the reducibility of Ni species, thus affecting CO2 conversion and product selectivity. In situ DRIFTS showed similar reaction pathways for La- and K- promoted catalysts with Ni catalysts. However, the La and K promoters significantly improved the formation of formate species on the Ni surface, facilitating CO2 conversion to useful products.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46508304","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}
Pub Date : 2022-11-09DOI: 10.3389/fceng.2022.1028811
B. Thijs, Lucas Hanssens, G. Heremans, Wauter Wangermez, J. Rongé, J. Martens
A three compartment solar formic acid generator was built using a Sn on Cu foam cathode and NiFe anode. A bipolar combination of a Fumasep FAD-PET-75 and Nafion 117 membrane was mounted between anode and middle compartment, which was filled with Amberlyst 15H ion exchanger beads. A Fumasep FAD-PET-75 membrane separated the middle compartment from the cathode. The generator was powered with a photovoltaic panel and fed with gaseous CO2 and water. Diluted formic acid solution was produced by flowing water through the middle compartment. Common PV-EC devices are operated using aqueous electrolyte and produce aqueous formate. In our PV-EC device, formic acid is produced straight away, avoiding the need for downstream operations to convert formate to formic acid. The electrolyser was matched with solar photovoltaic cells achieving a coupling efficiency as high as 95%. Our device produces formic acid at a faradaic efficiency of ca. 31% and solar-to-formic acid efficiency of ca. 2%. By producing formic acid from CO2 and water without any need of additional chemicals this electrolyser concept is attractive for use at remote locations with abundant solar energy. Formic acid serves as a liquid renewable fuel or chemical building block.
{"title":"Demonstration of a three compartment solar electrolyser with gas phase cathode producing formic acid from CO2 and water using Earth abundant metals","authors":"B. Thijs, Lucas Hanssens, G. Heremans, Wauter Wangermez, J. Rongé, J. Martens","doi":"10.3389/fceng.2022.1028811","DOIUrl":"https://doi.org/10.3389/fceng.2022.1028811","url":null,"abstract":"A three compartment solar formic acid generator was built using a Sn on Cu foam cathode and NiFe anode. A bipolar combination of a Fumasep FAD-PET-75 and Nafion 117 membrane was mounted between anode and middle compartment, which was filled with Amberlyst 15H ion exchanger beads. A Fumasep FAD-PET-75 membrane separated the middle compartment from the cathode. The generator was powered with a photovoltaic panel and fed with gaseous CO2 and water. Diluted formic acid solution was produced by flowing water through the middle compartment. Common PV-EC devices are operated using aqueous electrolyte and produce aqueous formate. In our PV-EC device, formic acid is produced straight away, avoiding the need for downstream operations to convert formate to formic acid. The electrolyser was matched with solar photovoltaic cells achieving a coupling efficiency as high as 95%. Our device produces formic acid at a faradaic efficiency of ca. 31% and solar-to-formic acid efficiency of ca. 2%. By producing formic acid from CO2 and water without any need of additional chemicals this electrolyser concept is attractive for use at remote locations with abundant solar energy. Formic acid serves as a liquid renewable fuel or chemical building block.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47190256","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}
Pub Date : 2022-11-07DOI: 10.3389/fceng.2022.1054242
Dixita Chettri, Susmita Nad, Ujjal Konar, A. Verma
Over-exploitation and energy security concerns of the diminishing fossil fuels is a challenge to the present global economy. Further, the negative impact of greenhouse gases released using conventional fuels has led to the need for searching for alternative biofuel sources with biomass in the form of lignocellulose coming up as among the potent candidates. The entrapped carbon source of the lignocellulose has multiple applications other than biofuel generation under the biorefinery approach. However, the major bottleneck in using lignocellulose for biofuel production is its recalcitrant nature. Carbohydrate Active Enzymes (CAZymes) are enzymes that are employed for the disintegration and consumption of lignocellulose biomass as the carbon source for the production of biofuels and bio-derivatives. However, the cost of enzyme production and their stability and catalytic efficiency under stressed conditions is a concern that hinders large-scale biofuel production and utilization. Search for novel CAZymes with superior activity and stability under industrial condition has become a major research focus in this area considering the fact that the most conventional CAZymes has low commercial viability. The gut of plant-eating herbivores and other organisms is a potential source of CAZyme with high efficiency. The review explores the potential of the gut microbiome of various organisms in the production of an efficient CAZyme system and the challenges in using the biofuels produced through this approach as an alternative to conventional biofuels.
{"title":"CAZyme from gut microbiome for efficient lignocellulose degradation and biofuel production","authors":"Dixita Chettri, Susmita Nad, Ujjal Konar, A. Verma","doi":"10.3389/fceng.2022.1054242","DOIUrl":"https://doi.org/10.3389/fceng.2022.1054242","url":null,"abstract":"Over-exploitation and energy security concerns of the diminishing fossil fuels is a challenge to the present global economy. Further, the negative impact of greenhouse gases released using conventional fuels has led to the need for searching for alternative biofuel sources with biomass in the form of lignocellulose coming up as among the potent candidates. The entrapped carbon source of the lignocellulose has multiple applications other than biofuel generation under the biorefinery approach. However, the major bottleneck in using lignocellulose for biofuel production is its recalcitrant nature. Carbohydrate Active Enzymes (CAZymes) are enzymes that are employed for the disintegration and consumption of lignocellulose biomass as the carbon source for the production of biofuels and bio-derivatives. However, the cost of enzyme production and their stability and catalytic efficiency under stressed conditions is a concern that hinders large-scale biofuel production and utilization. Search for novel CAZymes with superior activity and stability under industrial condition has become a major research focus in this area considering the fact that the most conventional CAZymes has low commercial viability. The gut of plant-eating herbivores and other organisms is a potential source of CAZyme with high efficiency. The review explores the potential of the gut microbiome of various organisms in the production of an efficient CAZyme system and the challenges in using the biofuels produced through this approach as an alternative to conventional biofuels.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45345864","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}
Pub Date : 2022-11-04DOI: 10.3389/fceng.2022.1038311
Ryan J. Stoklosa, R. Latona, D. Johnston
2,3-butanediol (2,3-BDO) is a platform chemical that can be converted to a wide array of products ranging from bio-based materials to sustainable aviation fuel. This chemical can be produced by a variety of microorganisms in fermentation processes. Challenges remain for high titer 2,3-BDO production during fermentation due to several parameters, but controlling oxygen is one of the most relevant processing parameters to ensure viable product output. This work investigated the fermentation of plant biomass sugars by the 2,3-BDO producer Paenibacillus polymyxa. Aerobic and oxygen limited fermentation conditions were initially evaluated using molasses-based media to determine cell growth and 2,3-BDO output. Similar conditions were then evaluated on hydrolysate from pretreated sweet sorghum bagasse (SSB) that contained fermentable sugars from structural polysaccharides. Fermentations in molasses media under aerobic conditions found that 2,3-BDO could be generated, but over time the amount of 2,3-BDO decreased due to conversion back into acetoin. Oxygen limited fermentation conditions exhibited improved biomass growth, but only limited suppression of 2,3-BDO conversion to acetoin occurred. Glucose depletion appeared to have a greater role influencing 2,3-BDO conversion back into acetoin. Further improvements in 2,3-BDO yields were found by utilizing detoxified SSB hydrolysate.
{"title":"Assessing oxygen limiting fermentation conditions for 2,3-butanediol production from Paenibacillus polymyxa","authors":"Ryan J. Stoklosa, R. Latona, D. Johnston","doi":"10.3389/fceng.2022.1038311","DOIUrl":"https://doi.org/10.3389/fceng.2022.1038311","url":null,"abstract":"2,3-butanediol (2,3-BDO) is a platform chemical that can be converted to a wide array of products ranging from bio-based materials to sustainable aviation fuel. This chemical can be produced by a variety of microorganisms in fermentation processes. Challenges remain for high titer 2,3-BDO production during fermentation due to several parameters, but controlling oxygen is one of the most relevant processing parameters to ensure viable product output. This work investigated the fermentation of plant biomass sugars by the 2,3-BDO producer Paenibacillus polymyxa. Aerobic and oxygen limited fermentation conditions were initially evaluated using molasses-based media to determine cell growth and 2,3-BDO output. Similar conditions were then evaluated on hydrolysate from pretreated sweet sorghum bagasse (SSB) that contained fermentable sugars from structural polysaccharides. Fermentations in molasses media under aerobic conditions found that 2,3-BDO could be generated, but over time the amount of 2,3-BDO decreased due to conversion back into acetoin. Oxygen limited fermentation conditions exhibited improved biomass growth, but only limited suppression of 2,3-BDO conversion to acetoin occurred. Glucose depletion appeared to have a greater role influencing 2,3-BDO conversion back into acetoin. Further improvements in 2,3-BDO yields were found by utilizing detoxified SSB hydrolysate.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46311409","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}
Pub Date : 2022-11-03DOI: 10.3389/fceng.2022.1046627
G. Jang, Y. Zhang, J. Keum, Y. Bootwala, M. Hatzell, D. Jassby, C. Tsouris
In this work, neutron computed tomography (CT) is employed to investigate the dissolution of porous aluminum electrodes during electrocoagulation (EC). Porous electrodes were chosen in efforts to reduce electric power requirements by using larger surface-area electrodes, having both inner and outer surface, for the EC process. Neutron CT allowed 3D reconstruction of the porous electrodes, and image analysis provided the volume of each electrode vs. thickness, which can indicate whether the inner surface is effectively involved in EC reactions. For the anode, the volume decreased uniformly throughout the thickness of the electrode, indicating that both the outer and inner surface participated in electrochemical dissolution, while the volume of the cathode increased uniformly vs. thickness, indicating deposition of material on both the outer and inner surface. The attenuation coefficient vs. thickness, increased for both anode and cathode, indicating surface chemistry changes. For the anode, the attenuation coefficient increased slightly but uniformly, probably due to aluminum oxide formation on the surface of the anode. For the cathode, the attenuation coefficient increased more than for the anode and nonuniformly. The higher increase in the attenuation coefficient for the cathode is due to precipitation of aluminum hydroxide on the electrode surface, which added hydrogen. Image analysis also showed that, although the attenuation coefficient increased throughout the thickness of the electrode, most of the hydroxide deposition occurred on the outer surface. Energy analysis showed that porous electrodes can be used to reduce process energy requirements by as much as 4 times compared to solid electrodes.
{"title":"Neutron tomography of porous aluminum electrodes used in electrocoagulation of groundwater","authors":"G. Jang, Y. Zhang, J. Keum, Y. Bootwala, M. Hatzell, D. Jassby, C. Tsouris","doi":"10.3389/fceng.2022.1046627","DOIUrl":"https://doi.org/10.3389/fceng.2022.1046627","url":null,"abstract":"In this work, neutron computed tomography (CT) is employed to investigate the dissolution of porous aluminum electrodes during electrocoagulation (EC). Porous electrodes were chosen in efforts to reduce electric power requirements by using larger surface-area electrodes, having both inner and outer surface, for the EC process. Neutron CT allowed 3D reconstruction of the porous electrodes, and image analysis provided the volume of each electrode vs. thickness, which can indicate whether the inner surface is effectively involved in EC reactions. For the anode, the volume decreased uniformly throughout the thickness of the electrode, indicating that both the outer and inner surface participated in electrochemical dissolution, while the volume of the cathode increased uniformly vs. thickness, indicating deposition of material on both the outer and inner surface. The attenuation coefficient vs. thickness, increased for both anode and cathode, indicating surface chemistry changes. For the anode, the attenuation coefficient increased slightly but uniformly, probably due to aluminum oxide formation on the surface of the anode. For the cathode, the attenuation coefficient increased more than for the anode and nonuniformly. The higher increase in the attenuation coefficient for the cathode is due to precipitation of aluminum hydroxide on the electrode surface, which added hydrogen. Image analysis also showed that, although the attenuation coefficient increased throughout the thickness of the electrode, most of the hydroxide deposition occurred on the outer surface. Energy analysis showed that porous electrodes can be used to reduce process energy requirements by as much as 4 times compared to solid electrodes.","PeriodicalId":73073,"journal":{"name":"Frontiers in chemical engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45043196","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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