The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jiwon Yang - One of the best experts on this subject based on the ideXlab platform.
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development of direct conversion method for microalgal biodiesel production using Wet Biomass of nannochloropsis salina
Bioresource Technology, 2015Co-Authors: Taehyoung Kim, Min S. Park, Gursong Yoo, William I Suh, Sanjiv K Mishra, Wasif Farooq, Myounghoon Moon, Anupama Shrivastav, Jiwon YangAbstract:Abstract In this work, the effects of several factors, such as temperature, reaction time, and solvent and acid quantity on in situ transesterification yield of Wet Nannochloropsis salina were investigated. Under equivalent total solvent volume to Biomass ratio, pure alcohol showed higher yield compared to alcohol–chloroform solvent. For esterifying 200 mg of Wet cells, 2 ml of methanol and 1 ml of ethanol was sufficient to complete in situ transesterification. Under temperatures of 105 °C or higher, 2.5% and 5% concentrations of sulfuric acid was able to successfully convert more than 90% of lipid within 30 min when methanol and ethanol was used as solvents respectively. Also, it was verified that the optimal condition found in small-scale experiments is applicable to larger scale using 2 L scale reactor as well.
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advances in direct transesterification of algal oils from Wet Biomass
Bioresource Technology, 2015Co-Authors: Jiyeon Park, Min S. Park, Jiwon YangAbstract:Abstract An interest in biodiesel as an alternative fuel for diesel engines has been increasing because of the issue of petroleum depletion and environmental concerns related to massive carbon dioxide emissions. Researchers are strongly driven to pursue the next generation of vegetable oil-based biodiesel. Oleaginous microalgae are considered to be a promising alternative oil source. To commercialize microalgal biodiesel, cost reductions in oil extraction and downstream biodiesel conversion are stressed. Herein, starting from an investigation of oil extraction from Wet microalgae, a review is conducted of transesterification using enzymes, homogeneous and heterogeneous catalysts, and yield enhancement by ultrasound, microwave, and supercritical process. In particular, there is a focus on direct transesterification as a simple and energy efficient process that omits a separate oil extraction step and utilizes Wet microalgal Biomass; however, it is still necessary to consider issues such as the purification of microalgal oils and upgrading of biodiesel properties.
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Optimization of variables affecting the direct transesterification of Wet Biomass from Nannochloropsis oceanica using ionic liquid as a co-solvent
Bioprocess and biosystems engineering, 2015Co-Authors: Hansol Lee, Won-sub Shin, Joo-young Jung, Chul Woong Kim, Jae Woo Lee, Jong-hee Kwon, Jiwon YangAbstract:Ionic liquids have many applications, one of which entails their utilization as powerful solvents. In the present study, various experimental conditions of ionic liquid-mediated direct transesterification were investigated in terms of lipid-extracting ionic liquids, catalyst, reaction time, reaction temperature and volume of methanol to achieve effective FAME conversion with Wet microalgal feedstock, Nannochloropsis oceanica. With ionic liquid, [Bmim][CF3SO3], highest fatty acid methyl ester (FAME) yield was shown. Among many experimental parameters, the two most critical factors to enhance FAME conversion were characteristic of ionic liquids and volume of methanol. Optimized ionic liquid-mediated direct transesterification of Wet N. oceanica, compared with a control experiment using chloroform and methanol, increased the FAME conversion yield by 11-fold.
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direct lipid extraction from Wet chlamydomonas reinhardtii Biomass using osmotic shock
Bioresource Technology, 2012Co-Authors: Gursong Yoo, Chul Woong Kim, Won Kun Park, Yoone Choi, Jiwon YangAbstract:High-cost downstream process is a major bottleneck for producing microalgal biodiesel at reasonable price. Conventional lipid extraction process necessitates Biomass drying process, which requires substantial amount of energy. In this regard, lipid extraction from Wet Biomass must be an attractive solution. However, it is almost impossible to recover lipid directly from Wet microalgae with current technology. In this study, we conceived osmotic shock treatment as a novel method to extract lipid efficiently. Osmotic shock treatment was applied directly to Wet Chlamydomonas reinhardtii Biomass with water content >99%, along with both polar and non-polar organic solvents. Our results demonstrated that osmotic shock could increase lipid recovery approximately 2 times. We also investigated whether the presence of cell wall or different cell stages could have any impact on lipid recovery. Cell wall-less mutant stains and senescent cell phase could display significantly increased lipid recovery. Taken together, our results suggested that osmotic shock is a promising technique for Wet lipid extraction from microalgal Biomass and successfully determined that specific manipulation of Biomass in certain cell phase could enhance lipid recovery further.
R D Tyagi - One of the best experts on this subject based on the ideXlab platform.
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detergent assisted ultrasonication aided in situ transesterification for biodiesel production from oleaginous yeast Wet Biomass
Bioresource Technology, 2017Co-Authors: Sravan Kumar Yellapu, Rajwinder Kaur, R D TyagiAbstract:Abstract In situ transesterification of oleaginous yeast Wet Biomass for fatty acid methyl esters (FAMEs) production using acid catalyst, methanol with or without N-Lauroyl sarcosine (N-LS) treatment was performed. The maximum FAMEs yield obtained with or without N-LS treatment in 24 h reaction time was 96.1 ± 1.9 and 71 ± 1.4% w/w, respectively. The N-LS treatment of Biomass followed by with or without ultrasonication revealed maximum FAMEs yield of 94.3 ± 1.9% and 82.9 ± 1.8% w/w using methanol to lipid molar ratio 360:1 and catalyst concentration 360 mM (64 μL H 2 SO 4 /g lipid) within 5 and 25 min reaction time, respectively. The FAMEs composition obtained in in situ transesterification was similar to that obtained with conventional two step lipid extraction and transesterification process. Biodiesel fuel properties (density, kinematic viscosity, cetane number and total glycerol) were in accordance with international standard (ASTM D6751 ), which suggests the suitability of biodiesel as a fuel.
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detergent assisted ultrasonication aided in situ transesterification for biodiesel production from oleaginous yeast Wet Biomass
Bioresource Technology, 2017Co-Authors: Sravan Kumar Yellapu, Rajwinder Kaur, R D TyagiAbstract:Abstract In situ transesterification of oleaginous yeast Wet Biomass for fatty acid methyl esters (FAMEs) production using acid catalyst, methanol with or without N-Lauroyl sarcosine (N-LS) treatment was performed. The maximum FAMEs yield obtained with or without N-LS treatment in 24 h reaction time was 96.1 ± 1.9 and 71 ± 1.4% w/w, respectively. The N-LS treatment of Biomass followed by with or without ultrasonication revealed maximum FAMEs yield of 94.3 ± 1.9% and 82.9 ± 1.8% w/w using methanol to lipid molar ratio 360:1 and catalyst concentration 360 mM (64 μL H 2 SO 4 /g lipid) within 5 and 25 min reaction time, respectively. The FAMEs composition obtained in in situ transesterification was similar to that obtained with conventional two step lipid extraction and transesterification process. Biodiesel fuel properties (density, kinematic viscosity, cetane number and total glycerol) were in accordance with international standard (ASTM D6751 ), which suggests the suitability of biodiesel as a fuel.
Yukihiko Matsumura - One of the best experts on this subject based on the ideXlab platform.
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inhibition of char deposition using a particle bed in heating section of supercritical water gasification
Korean Journal of Chemical Engineering, 2016Co-Authors: Soichi Hirota, Shuhei Inoue, Takahito Inoue, Yoshifumi Kawai, Yasutaka Wada, Takashi Noguchi, Yukihiko MatsumuraAbstract:Supercritical water gasification (SCWG) has attracted attention as a technology for utilizing Wet Biomass. We used a fluidized bed of alumina particles to prevent blockage of a SCWG reactor. A glucose solution was heated in the reactor with and without fluidized alumina particles. In the absence of alumina particles, char particles formed homogeneously in the reactor, but the use of a fluidized bed resulted in accumulation of char particles at the reactor’s exit rather than inside the reactor. Therefore, the fluidized bed was effective at preventing blockage of the reactor. However, the alumina particles did not remove deposits from the reactor’s walls. Instead, the fluidized bed caused larger char particles to form, preventing their adhesion to the reactor’s wall.
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supercritical water treatment of Biomass for energy and material recovery
Combustion Science and Technology, 2006Co-Authors: Yukihiko Matsumura, Kazuhide Okuda, Seiichi Takami, Satoshi Ohara, Mitsuo Umetsu, Mitsuru Sasaki, Tadafumi AdschiriAbstract:ABSTRACT Supercritical water liquefaction and gasification is reviewed with the introduction of some recent findings by the authors. Supercritical water gasification is suitable for recovery of energy from Wet Biomass while supercritical water liquefaction opens the door to effective treatment of Biomass species in terms of material recovery. Cellulose, one of the main components of Biomass, is completely dissolved in supercritical water. Once dissolved, reaction of cellulose can take place swiftly by hydrolysis and pyrolysis. The hydrolysis reaction, otherwise slower than pyrolysis due to the mass transfer limitation, is faster than decomposition in supercritical water, and a possibility of efficient glucose recovery has been shown. Once dissolved, super saturation is kept when the solution is cooled down, and swift hydrolysis by enzyme is also possible. Lignin can be also converted into specialty chemicals by using supercritical cresol/water mixture as a solvent. Dissolution of cellulose also enables ef...
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hydrothermal pulping of Wet Biomass as pretreatment for supercritical water gasiificalion studied using cabbage as a model compound
Journal of The Japan Institute of Energy, 2003Co-Authors: Akitomo Kato, Yukihiko MatsumuraAbstract:Liquidization of Wet Biomass (cabbage) was conducted at 423-473 K and 1.2-1.3MPa. From observation with electron microscope and analysis of components, it was found that liquidization was caused by the breakdown of cell structure, mainly decomposition of hemicellulose. Liquidized product was slurry liquid, which could be described as a Newtonian fluid. The higher the temperature for liquidization treatment was, the lower the apparent viscosity of liquidized product was. It was also confirmed that gasification in supercritical water (673K, 25MPa) was promoted by liquidization treatment at 423 K.
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evaluation of supercritical water gasification and biomethanation for Wet Biomass utilization in japan
Energy Conversion and Management, 2002Co-Authors: Yukihiko MatsumuraAbstract:Two Wet Biomass gasification processes, supercritical water gasification and biomethanation, were evaluated from energy, environmental, and economic aspects. Gasification of 1 dry-t/d of water hyacinth was taken as a model case. Assumptions were made that system should be energetically independent, that no environmentally harmful material should be released, and that carbon dioxide should be removed from the product gas. Energy efficiency, carbon dioxide payback time, and price of the product gas were chosen as indices for energy, environmental, and economic evaluation, respectively. Under the conditions assumed here, supercritical water gasification is evaluated to be more advantageous over biomethanation, but the cost of the product gas is still 1.86 times more expensive than city gas in Tokyo. To improve efficiency of supercritical water gasification, improvement of heat exchanger efficiency is effective. Utilization of fermentation sludge will make biomethanation much more advantageous.
Kefa Cen - One of the best experts on this subject based on the ideXlab platform.
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comparison between heterofermentation and autofermentation in hydrogen production from arthrospira spirulina platensis Wet Biomass
International Journal of Hydrogen Energy, 2012Co-Authors: Jun Cheng, Ao Xia, Wenlu Song, Junhu Zhou, Kefa CenAbstract:Abstract Hydrogen production from Arthrospira (Spirulina) platensis Wet Biomass through heterofermentation by the [FeFe] hydrogenase of hydrogenogens (hydrogen-producing bacteria) and autofermentation by the [NiFe] hydrogenase of Arthrospira platensis was discussed under dark anaerobic conditions. In heterofermentation, Wet cyanobacterial Biomass without pretreatment was hardly utilized by hydrogenogens for hydrogen production. But the carbohydrates in cyanobacterial cells released after cell wall disruption were effectively utilized by hydrogenogens for hydrogen production. Wet cyanobacterial Biomass was pretreated with boiling and bead milling, ultrasonication, and ultrasonication and enzymatic hydrolysis. Wet cyanobacterial Biomass pretreated with ultrasonication and enzymatic hydrolysis achieved the maximum reducing sugar yield of 0.407 g/g-DW (83.0% of the theoretical reducing sugar yield). Different concentrations (10 g/l to 40 g/l) of pretreated Wet cyanobacterial Biomass were used as substrate to produce fermentative hydrogen by hydrogenogens, which were domesticated with the pretreated Wet cyanobacterial Biomass as carbon source. The maximum hydrogen yield of 92.0 ml H 2 /g-DW was obtained at 20 g/l of Wet cyanobacterial Biomass. The main soluble metabolite products (SMPs) in the residual solutions from heterofermentation were acetate and butyrate. In autofermentation, hydrogen yield decreased from 51.4 ml H 2 /g-DW to 11.0 ml H 2 /g-DW with increasing substrate concentration from 1 g/l to 20 g/l. The main SMPs in the residual solutions from autofermentation were acetate and ethanol. The hydrogen production peak rate and hydrogen yield at 20 g/l of Wet cyanobacterial Biomass in heterofermentation showed 110- and 8.4-fold increases, respectively, relative to those in autofementation.
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Combination of dark- and photo-fermentation to improve hydrogen production from Arthrospira platensis Wet Biomass with ammonium removal by zeolite
International Journal of Hydrogen Energy, 2012Co-Authors: Jun Cheng, Ao Xia, Richen Lin, Yaqiong Liu, Kefa CenAbstract:Abstract Arthrospira platensis Wet Biomass was subjected to microwave-assisted dilute H2SO4 pretreatment to improve saccharification by hydrolysis with glucoamylase and hydrogen production from dark-fermentation. When the hydrolyzed Biomass from A. platensis was inoculated with hydrogenogens (heat-treated anaerobic sludge) to produce hydrogen during dark-fermentation, the maximum hydrogen yield of 96.6 ml H2/g DW was obtained. Because high concentration of N H 4 + (31.6–56.5 mM) in the residual solution (also containing acetate and butyrate) obtained from dark-fermentation can significantly inhibit the activities of photosynthetic bacteria in sequential photo-fermentation, a modified zeolite was used to extract N H 4 + by ion exchange to reduce the N H 4 + content to 2.2–2.7 mM (91.8%–95.8% of NH4+ removal efficiency). The treated residual solution was reused for hydrogen production in sequential photo-fermentation. The maximum hydrogen yield from A. platensis Wet Biomass was significantly enhanced from 96.6 to 337.0 ml H2/g DW using a combination of dark- and photo-fermentation.
Sravan Kumar Yellapu - One of the best experts on this subject based on the ideXlab platform.
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detergent assisted ultrasonication aided in situ transesterification for biodiesel production from oleaginous yeast Wet Biomass
Bioresource Technology, 2017Co-Authors: Sravan Kumar Yellapu, Rajwinder Kaur, R D TyagiAbstract:Abstract In situ transesterification of oleaginous yeast Wet Biomass for fatty acid methyl esters (FAMEs) production using acid catalyst, methanol with or without N-Lauroyl sarcosine (N-LS) treatment was performed. The maximum FAMEs yield obtained with or without N-LS treatment in 24 h reaction time was 96.1 ± 1.9 and 71 ± 1.4% w/w, respectively. The N-LS treatment of Biomass followed by with or without ultrasonication revealed maximum FAMEs yield of 94.3 ± 1.9% and 82.9 ± 1.8% w/w using methanol to lipid molar ratio 360:1 and catalyst concentration 360 mM (64 μL H 2 SO 4 /g lipid) within 5 and 25 min reaction time, respectively. The FAMEs composition obtained in in situ transesterification was similar to that obtained with conventional two step lipid extraction and transesterification process. Biodiesel fuel properties (density, kinematic viscosity, cetane number and total glycerol) were in accordance with international standard (ASTM D6751 ), which suggests the suitability of biodiesel as a fuel.
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detergent assisted ultrasonication aided in situ transesterification for biodiesel production from oleaginous yeast Wet Biomass
Bioresource Technology, 2017Co-Authors: Sravan Kumar Yellapu, Rajwinder Kaur, R D TyagiAbstract:Abstract In situ transesterification of oleaginous yeast Wet Biomass for fatty acid methyl esters (FAMEs) production using acid catalyst, methanol with or without N-Lauroyl sarcosine (N-LS) treatment was performed. The maximum FAMEs yield obtained with or without N-LS treatment in 24 h reaction time was 96.1 ± 1.9 and 71 ± 1.4% w/w, respectively. The N-LS treatment of Biomass followed by with or without ultrasonication revealed maximum FAMEs yield of 94.3 ± 1.9% and 82.9 ± 1.8% w/w using methanol to lipid molar ratio 360:1 and catalyst concentration 360 mM (64 μL H 2 SO 4 /g lipid) within 5 and 25 min reaction time, respectively. The FAMEs composition obtained in in situ transesterification was similar to that obtained with conventional two step lipid extraction and transesterification process. Biodiesel fuel properties (density, kinematic viscosity, cetane number and total glycerol) were in accordance with international standard (ASTM D6751 ), which suggests the suitability of biodiesel as a fuel.
