The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Fikret Kargi - One of the best experts on this subject based on the ideXlab platform.
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hydrogen gas production from cheese whey powder cwp solution by thermophilic Dark Fermentation
International Journal of Hydrogen Energy, 2012Co-Authors: Fikret Kargi, Nur Seza Eren, Serpil OzmihciAbstract:Abstract Hydrogen gas production from cheese whey powder (CWP) solution by thermophilic Dark Fermentation was investigated at 55 °C. Experiments were performed at different initial total sugar concentrations varying between 5.2 and 28.5 g L−1 with a constant initial bacteria concentration of 1 g L−1. The highest cumulative hydrogen evolution (257 mL) was obtained with 20 g L−1 total sugar (substrate) concentration within 360 h while the highest H2 formation rate (2.55 mL h−1) and yield (1.03 mol H2 mol−1 glucose) were obtained at 5.2 and 9.5 g L−1 substrate concentrations, respectively. The specific H2 production rate (SHPR = 4.5 mL h−1 g−1cells) reached the highest level at 20 g L−1 total sugar concentration. Total volatile fatty acid (TVFA) concentration increased with increasing initial total sugar content and reached the highest level (14.15 g L−1) at 28.5 g L−1 initial substrate concentration. The experimental data was correlated with the Gompertz equation and the constants were determined. The optimum initial total sugar concentration was 20 g L−1 above which substrate and product (VFA) inhibitions were observed.
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comparison of bio hydrogen production from hydrolyzed wheat starch by mesophilic and thermophilic Dark Fermentation
International Journal of Hydrogen Energy, 2010Co-Authors: Ayse Cakir, Serpil Ozmihci, Fikret KargiAbstract:Abstract Hydrogen gas production potentials of acid-hydrolyzed and boiled ground wheat were compared in batch Dark Fermentations under mesophilic (37 °C) and thermophilic (55 °C) conditions. Heat-treated anaerobic sludge was used as the inoculum and the hydrolyzed ground wheat was supplemented by other nutrients. The highest cumulative hydrogen gas production (752 ml) was obtained from the acid-hydrolyzed ground wheat starch at 55 °C and the lowest (112 ml) was with the boiled wheat starch within 10 days. The highest rate of hydrogen gas formation (7.42 ml H2 h−1) was obtained with the acid-hydrolyzed and the lowest (1.12 ml H2 h−1) with the boiled wheat at 55 °C. The highest hydrogen gas yield (333 ml H2 g−1 total sugar or 2.40 mol H2 mol−1 glucose) and final total volatile fatty acid (TVFA) concentration (10.08 g L−1) were also obtained with the acid-hydrolyzed wheat under thermophilic conditions (55 °C). Dark Fermentation of acid-hydrolyzed ground wheat under thermophilic conditions (55 °C) was proven to be more beneficial as compared to mesophilic or thermophilic Fermentation of boiled (partially hydrolyzed) wheat starch.
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Dark Fermentation of acid hydrolyzed ground wheat starch for bio hydrogen production by periodic feeding and effluent removal
International Journal of Hydrogen Energy, 2010Co-Authors: Rana Sagnak, Ilgi Karapinar Kapdan, Fikret KargiAbstract:Abstract Dark Fermentation of acid hydrolyzed ground wheat starch for bio-hydrogen production by periodic feeding and effluent removal was investigated at different feeding intervals. Ground wheat was acid hydrolyzed at pH = 3 and T = 121 °C for 30 min using an autoclave. The resulting sugar solution was subjected to Dark Fermentation with periodic feeding and effluent removal. The feed solution contained 9 ± 0.5 g L −1 total sugar supplemented with some nutrients. Depending on the feeding intervals hydraulic residence time (HRT) was varied between 6 and 60 h. Steady-state daily hydrogen production increased with decreasing HRT. The highest daily hydrogen production (305 ml d −1 ) and volumetric hydrogen production rate (1220 ml H 2 L −1 d −1 ) were obtained at HRT of 6 h. Hydrogen yield (130 ml H 2 g −1 total sugar) reached the highest level at HRT = 24 h. Effluent total sugar concentration decreased, biomass concentration and yield increased with increasing HRT indicating more effective sugar Fermentation at high HRTs. Dark Fermentation end product profile shifted from acetic to butyric acid with increasing HRT. High acetic/butyric acid ratio obtained at low HRTs resulted in high hydrogen yields.
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microbial culture selection for bio hydrogen production from waste ground wheat by Dark Fermentation
International Journal of Hydrogen Energy, 2009Co-Authors: Hidayet Argun, Fikret Kargi, Ilgi Karapinar KapdanAbstract:Abstract Hydrogen formation performances of different anaerobic bacteria were investigated in batch Dark Fermentation of waste wheat powder solution (WPS). Serum bottles containing wheat powder were inoculated with pure cultures of Clostridium acetobutylicum (CAB), Clostridium butyricum (CB), Enterobacter aerogenes (EA), heat-treated anaerobic sludge (ANS) and a mixture of those cultures (MIX). Cumulative hydrogen formation (CHF), hydrogen yield (HY) and specific hydrogen production rate (SHPR) were determined for every culture. The heat-treated anaerobic sludge was found to be the most effective culture with a cumulative hydrogen formation of 560 ml, hydrogen yield of 223 ml H2 g−1 starch and a specific hydrogen production rate of 32.1 ml H2 g−1 h−1.
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optimization of media composition for hydrogen gas production from hydrolyzed wheat starch by Dark Fermentation
International Journal of Hydrogen Energy, 2008Co-Authors: Rukiye Oztekin, Ilgi Karapinar Kapdan, Fikret Kargi, Hidayet ArgunAbstract:Abstract Effects of N/C, P/C and Fe(II)/C ratios in Fermentation medium on biohydrogen production by Dark Fermentation of acid-hydrolyzed wheat starch was investigated. The powdered wheat was autoclaved at pH = 3 and 90 °C for 15 min and the resulting sugar solution was fermented after external addition of N, P and Fe(II) to overcome nutrient limitations. Box–Wilson statistical experiment design was used by considering the N/C (0–0.05, w w −1 ), P/C (0–0.02) and Fe(II)/C (0–0.03) ratios as the independent variables while the hydrogen yield and specific hydrogen production rate (SHPR) were the objective functions to be optimized. A quadratic response function was used to correlate the response functions with the independent variables. Low levels of the variables (N/C Y = 2.84 mol H 2 mol −1 glucose) were N/C = 0.02, P/C = 0.008 and Fe(II)/C = 0.015. The maximum SHPR (96 mL H 2 g −1 biomass h −1 ) was obtained at N/C = 0.025, P/C = 0.008 and Fe(II)/C = 0.015 (w w −1 ).
Hidayet Argun - One of the best experts on this subject based on the ideXlab platform.
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Bio-hydrogen production from waste peach pulp by Dark Fermentation: Effect of inoculum addition
International Journal of Hydrogen Energy, 2017Co-Authors: Hidayet Argun, Siaka DaoAbstract:This study reports the effect of inoculum addition on bio-hydrogen production from waste peach pulp by Dark Fermentation. Batch mode experiments were done at constant 200 g/L waste peach pulp concentration by varying the inoculum addition between 0 and 10% (v/v). The highest hydrogen yield (123.27 mLH2/gTOC) was obtained at 5% inoculum addition with 46% hydrogen content in the gas phase. On the other hand highest hydrogen formation rate (35.6 mLH2/h) and TOC removal (25.17%) were obtained with 10% sludge addition. Hydrogen production yield increased by increasing the sludge addition from 0 to 5% and then decreased at higher values. The control bottle showed a significant performance in terms of hydrogen production indicating the contribution of natural microflora for hydrogen gas formation. However, hydrogen formation rate and yield increased significantly with inoculation. The addition of 5% (v/v) inoculum resulted most convenient hydrogen formation compared with other ratios. The minimum amount of inoculum per substrate at 5% (v/v) was 0.009 g biomass/g TS.
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Photo-fermentative hydrogen gas production from Dark Fermentation effluent of ground wheat solution: Effects of light source and light intensity
International Journal of Hydrogen Energy, 2010Co-Authors: Hidayet ArgunAbstract:Abstract Dark Fermentation effluent of wheat powder solution was subjected to light Fermentation for bio-hydrogen production using different light sources and intensities. Tungsten, fluorescent, infrared (IR), halogen lamps were used as light sources with a light intensity of 270 Wm −2 along with sunlight. Pure culture of Rhodobacter sphaeroides -RV was used in batch light Fermentation experiments. Halogen lamp was found to be the most suitable light source yielding the highest cumulative hydrogen formation (CHF, 252 ml) and yield (781 ml H 2 g −1 TVFA). In the second set of experiments, light Fermentations were performed at different light intensities (1–10 klux) using halogen lamp. The optimum light intensity was found to be 5 klux (approx. 176 Wm −2 ) resulting in the highest CHF (88 ml) and hydrogen yield (1037 ml H 2 g −1 TVFA). Hydrogen formation was limited by the availability of light at low light intensities below 5 klux and was inhibited by the excess light above 5 klux.
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microbial culture selection for bio hydrogen production from waste ground wheat by Dark Fermentation
International Journal of Hydrogen Energy, 2009Co-Authors: Hidayet Argun, Fikret Kargi, Ilgi Karapinar KapdanAbstract:Abstract Hydrogen formation performances of different anaerobic bacteria were investigated in batch Dark Fermentation of waste wheat powder solution (WPS). Serum bottles containing wheat powder were inoculated with pure cultures of Clostridium acetobutylicum (CAB), Clostridium butyricum (CB), Enterobacter aerogenes (EA), heat-treated anaerobic sludge (ANS) and a mixture of those cultures (MIX). Cumulative hydrogen formation (CHF), hydrogen yield (HY) and specific hydrogen production rate (SHPR) were determined for every culture. The heat-treated anaerobic sludge was found to be the most effective culture with a cumulative hydrogen formation of 560 ml, hydrogen yield of 223 ml H2 g−1 starch and a specific hydrogen production rate of 32.1 ml H2 g−1 h−1.
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optimization of media composition for hydrogen gas production from hydrolyzed wheat starch by Dark Fermentation
International Journal of Hydrogen Energy, 2008Co-Authors: Rukiye Oztekin, Ilgi Karapinar Kapdan, Fikret Kargi, Hidayet ArgunAbstract:Abstract Effects of N/C, P/C and Fe(II)/C ratios in Fermentation medium on biohydrogen production by Dark Fermentation of acid-hydrolyzed wheat starch was investigated. The powdered wheat was autoclaved at pH = 3 and 90 °C for 15 min and the resulting sugar solution was fermented after external addition of N, P and Fe(II) to overcome nutrient limitations. Box–Wilson statistical experiment design was used by considering the N/C (0–0.05, w w −1 ), P/C (0–0.02) and Fe(II)/C (0–0.03) ratios as the independent variables while the hydrogen yield and specific hydrogen production rate (SHPR) were the objective functions to be optimized. A quadratic response function was used to correlate the response functions with the independent variables. Low levels of the variables (N/C Y = 2.84 mol H 2 mol −1 glucose) were N/C = 0.02, P/C = 0.008 and Fe(II)/C = 0.015. The maximum SHPR (96 mL H 2 g −1 biomass h −1 ) was obtained at N/C = 0.025, P/C = 0.008 and Fe(II)/C = 0.015 (w w −1 ).
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biohydrogen production by Dark Fermentation of wheat powder solution effects of c n and c p ratio on hydrogen yield and formation rate
International Journal of Hydrogen Energy, 2008Co-Authors: Hidayet Argun, Fikret Kargi, Ilgi Karapinar Kapdan, Rukiye OztekinAbstract:Abstract The effects of C/N and C/P ratio on hydrogen yield and specific production rate were investigated in Dark Fermentation of wheat powder solution (WPS) by external addition of N and P since the wheat powder was N and P deficient. A Box–Wilson statistical experiment design approach was used. C/N ratio was varied between 20 and 200 while C/P ratio was between 50 and 1000. A quadratic response function was used to correlate the objective functions with the independent variables and the response function coefficients were determined by regression analysis. Hydrogen yield increased with increasing C/N and C/P ratios. Low nitrogen concentrations required low phosphorous contents for high hydrogen yields. A C/N ratio of 200 and C/P ratio of 1000 yielded the highest H 2 yield of 281 ml H 2 g - 1 starch at STP. SHPR also increased with increasing C/N and C/P ratios. Again the highest SHPR ( 98 ml H 2 g - 1 biomass h - 1 at STP) was obtained at C/N and C/P ratios of 200 and 1000, respectively. The C/N/P ratio maximizing the yield and formation rate of hydrogen was 100/0.5/0.1 ( w w - 1 w - 1 ) .
Ilgi Karapinar Kapdan - One of the best experts on this subject based on the ideXlab platform.
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Dark Fermentation of acid hydrolyzed ground wheat starch for bio hydrogen production by periodic feeding and effluent removal
International Journal of Hydrogen Energy, 2010Co-Authors: Rana Sagnak, Ilgi Karapinar Kapdan, Fikret KargiAbstract:Abstract Dark Fermentation of acid hydrolyzed ground wheat starch for bio-hydrogen production by periodic feeding and effluent removal was investigated at different feeding intervals. Ground wheat was acid hydrolyzed at pH = 3 and T = 121 °C for 30 min using an autoclave. The resulting sugar solution was subjected to Dark Fermentation with periodic feeding and effluent removal. The feed solution contained 9 ± 0.5 g L −1 total sugar supplemented with some nutrients. Depending on the feeding intervals hydraulic residence time (HRT) was varied between 6 and 60 h. Steady-state daily hydrogen production increased with decreasing HRT. The highest daily hydrogen production (305 ml d −1 ) and volumetric hydrogen production rate (1220 ml H 2 L −1 d −1 ) were obtained at HRT of 6 h. Hydrogen yield (130 ml H 2 g −1 total sugar) reached the highest level at HRT = 24 h. Effluent total sugar concentration decreased, biomass concentration and yield increased with increasing HRT indicating more effective sugar Fermentation at high HRTs. Dark Fermentation end product profile shifted from acetic to butyric acid with increasing HRT. High acetic/butyric acid ratio obtained at low HRTs resulted in high hydrogen yields.
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microbial culture selection for bio hydrogen production from waste ground wheat by Dark Fermentation
International Journal of Hydrogen Energy, 2009Co-Authors: Hidayet Argun, Fikret Kargi, Ilgi Karapinar KapdanAbstract:Abstract Hydrogen formation performances of different anaerobic bacteria were investigated in batch Dark Fermentation of waste wheat powder solution (WPS). Serum bottles containing wheat powder were inoculated with pure cultures of Clostridium acetobutylicum (CAB), Clostridium butyricum (CB), Enterobacter aerogenes (EA), heat-treated anaerobic sludge (ANS) and a mixture of those cultures (MIX). Cumulative hydrogen formation (CHF), hydrogen yield (HY) and specific hydrogen production rate (SHPR) were determined for every culture. The heat-treated anaerobic sludge was found to be the most effective culture with a cumulative hydrogen formation of 560 ml, hydrogen yield of 223 ml H2 g−1 starch and a specific hydrogen production rate of 32.1 ml H2 g−1 h−1.
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optimization of media composition for hydrogen gas production from hydrolyzed wheat starch by Dark Fermentation
International Journal of Hydrogen Energy, 2008Co-Authors: Rukiye Oztekin, Ilgi Karapinar Kapdan, Fikret Kargi, Hidayet ArgunAbstract:Abstract Effects of N/C, P/C and Fe(II)/C ratios in Fermentation medium on biohydrogen production by Dark Fermentation of acid-hydrolyzed wheat starch was investigated. The powdered wheat was autoclaved at pH = 3 and 90 °C for 15 min and the resulting sugar solution was fermented after external addition of N, P and Fe(II) to overcome nutrient limitations. Box–Wilson statistical experiment design was used by considering the N/C (0–0.05, w w −1 ), P/C (0–0.02) and Fe(II)/C (0–0.03) ratios as the independent variables while the hydrogen yield and specific hydrogen production rate (SHPR) were the objective functions to be optimized. A quadratic response function was used to correlate the response functions with the independent variables. Low levels of the variables (N/C Y = 2.84 mol H 2 mol −1 glucose) were N/C = 0.02, P/C = 0.008 and Fe(II)/C = 0.015. The maximum SHPR (96 mL H 2 g −1 biomass h −1 ) was obtained at N/C = 0.025, P/C = 0.008 and Fe(II)/C = 0.015 (w w −1 ).
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biohydrogen production by Dark Fermentation of wheat powder solution effects of c n and c p ratio on hydrogen yield and formation rate
International Journal of Hydrogen Energy, 2008Co-Authors: Hidayet Argun, Fikret Kargi, Ilgi Karapinar Kapdan, Rukiye OztekinAbstract:Abstract The effects of C/N and C/P ratio on hydrogen yield and specific production rate were investigated in Dark Fermentation of wheat powder solution (WPS) by external addition of N and P since the wheat powder was N and P deficient. A Box–Wilson statistical experiment design approach was used. C/N ratio was varied between 20 and 200 while C/P ratio was between 50 and 1000. A quadratic response function was used to correlate the objective functions with the independent variables and the response function coefficients were determined by regression analysis. Hydrogen yield increased with increasing C/N and C/P ratios. Low nitrogen concentrations required low phosphorous contents for high hydrogen yields. A C/N ratio of 200 and C/P ratio of 1000 yielded the highest H 2 yield of 281 ml H 2 g - 1 starch at STP. SHPR also increased with increasing C/N and C/P ratios. Again the highest SHPR ( 98 ml H 2 g - 1 biomass h - 1 at STP) was obtained at C/N and C/P ratios of 200 and 1000, respectively. The C/N/P ratio maximizing the yield and formation rate of hydrogen was 100/0.5/0.1 ( w w - 1 w - 1 ) .
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Light Fermentation of Dark Fermentation effluent for bio-hydrogen production by different Rhodobacter species at different initial volatile fatty acid (VFA) concentrations
International Journal of Hydrogen Energy, 2008Co-Authors: Hidayet Argun, Ilgi Karapinar KapdanAbstract:Abstract Three different Rhodobacter sphaeroides (RS) strains (RS–NRRL, RS–DSMZ and RS–RV) and their combinations were used for light Fermentation of Dark Fermentation effluent of ground wheat containing volatile fatty acids (VFA). In terms of cumulative hydrogen formation, RS–NRRL performed better than the other two strains producing 48 ml H2 in 180 h. However, RS–RV resulted in the highest hydrogen yield of 250 ml H2 g−1 TVFA. Specific hydrogen production rate (SHPR) with the RS–NRRL was also better in comparison to the others (13.8 ml H2 g−1 biomass h−1). When combinations of those three strains were used, RS–RV + RS–DSMZ resulted in the highest cumulative hydrogen formation (90 ml H2 in 330 h). However, hydrogen yield (693 ml H2 g−1 TVFA) and SHPR (12.1 ml H2 g−1 biomass h−1) were higher with the combination of the three different strains. On the basis of Gompertz equation coefficients mixed culture of the three different strains gave the highest cumulative hydrogen and formation rate probably due to synergistic interaction among the strains. The effects of initial TVFA and NH4–N concentrations on hydrogen formation were investigated for the mixed culture of the three strains. The optimum TVFA and NH4–N concentrations maximizing the hydrogen formation were determined as 2350 and 47 mg L−1, respectively.
Eric Trably - One of the best experts on this subject based on the ideXlab platform.
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enhancement of mass transfer conditions to increase the productivity and efficiency of Dark Fermentation in continuous reactors
Fuel, 2019Co-Authors: Rodolfo Palomobriones, Nicolas Bernet, Eric Trably, Lourdes B Celis, H O Mendezacosta, Elias RazofloresAbstract:Abstract Hydrogen (H 2 ) produced by Dark Fermentation is an alternative to fulfill the requirements of the transportation sector and to be a complementary source in the forthcoming electricity grid. However, the Dark fermentative H 2 production is limited by the accumulation of H 2 in the Fermentation broth. In continuous stirred-tank reactors (CSTR), such phenomenon is associated with poor mass transfer conditions. Nevertheless, this parameter has been scarcely considered to enhance H 2 production. In this research, the effect of the H 2 mass transfer conditions on the productivity and efficiency of continuous H 2 production was evaluated using a series of CSTR operated at H 2 mass transfer coefficients (k L a) ranging from 1.04 to 4.23 1/h. The results showed that volumetric H 2 production rate (VHPR) and H 2 yield increased 74 and 78%, respectively, due to enhanced mass transfer conditions. This behavior was driven by 53% decrease of the dissolved H 2 concentration. More specifically, the maximum VHPR of 7.66 L/L-d with a H 2 yield of 1.1 mol H 2 /mol hexose was obtained at a k L a = 4.23 1/h. Furthermore, 16S-DGGE analysis and sequencing revealed that Clostridium and Lactobacillus were the dominant bacterial genera in continuous operation. In particular, Clostridium increased its occurrence at k L a of 2.72–4.23 1/h as a response to lower dissolved H 2 concentrations. The novelty of this work relies on the demonstration that mass transfer conditions control not only the H 2 accumulation and reactor performance (VHPR and H 2 yield), but they also influence the metabolic pathways and the composition of the microbial community.
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Effect of total solids content on biohydrogen production and lactic acid accumulation during Dark Fermentation of organic waste biomass
Bioresource Technology, 2018Co-Authors: Anish Ghimire, Elisabeth A. Cazier, Luigi Frunzo, Piet N L Lens, Giovanni Esposito, Francesco Pirozzi, Eric Trably, Renaud EscudieAbstract:Production of biohydrogen and related metabolic by-products was investigated in Solid State Dark Fermentation (SSDF) of food waste (FW) and wheat straw (WS). The effect of the total solids (TS) content and H2 partial pressure (ppH2), two of the main operating factors of SSDF, were investigated. Batch tests with FW at 10, 15, 20, 25 and 30% TS showed considerable effects of the TS on metabolites distribution. H2 production was strongly inhibited for TS contents higher than 15% with a concomitant accumulation of lactic acid and a decrease in substrate conversion. Varying the ppH2 had no significant effect on the conversion products and overall degradation of FW and WS, suggesting that ppH2 was not the main limiting factor in SSDF. This study showed that the conversion of complex substrates by SSDF depends on the substrate type and is limited by the TS content.
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Biohydrogen production from food waste: Current status, limitations, and future perspectives.
Bioresource technology, 2017Co-Authors: Yeo-myeong Yun, Antonella Marone, Eric Trably, Mo-kwon Lee, Sang-ryong Shin, Min-gyun Kim, Si-kyung Cho, Dong-hoon KimAbstract:Among the various biological routes for H2 production, Dark Fermentation is considered the most practically applicable owing to its capability to degrade organic wastes and high H2 production rate. Food waste (FW) has high carbohydrate content and easily hydrolysable in nature, exhibiting higher H2 production potential than that of other organic wastes. In this review article, first, the current status of H2 production from FW by Dark Fermentation and the strategies applied for enhanced performance are briefly summarized. Then, the technical and economic limitations of Dark Fermentation of FW are thoroughly discussed. Economic assessment revealed that the economic feasibility of H2 production from FW by Dark Fermentation is questionable. Current efforts to further increase H2 yield and waste removal efficiency are also introduced. Finally, future perspectives along with possible routes converting Dark Fermentation effluent to valuable fuels and chemicals are discussed.
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Coupling Dark Fermentation and microbial electrolysis to enhance bio-hydrogen production from agro-industrial wastewaters and by-products in a bio-refinery framework
International Journal of Hydrogen Energy, 2017Co-Authors: Antonella Marone, Olga R. Ayala-campos, Alessandro A. Carmona-martínez, Victor Alcaraz-gonzalez, Roman Moscoviz, Eric Latrille, Jean-philippe Steyer, Eric Trably, Nicolas BernetAbstract:The aim of this work is to evaluate biohydrogen production from agro-industrial wastewaters and by-products, by combining Dark Fermentation and microbial electrolysis in a two-step cascade process. Such coupling of both technologies constitutes a technological building block within a concept of environmental biorefinery where sustainable production of renewable energy is expected. Six different wastewaters and industrial by-products coming from cheese, fruit juice, paper, sugar, fruit processing and spirits factories were evaluated for the feasibility of hydrogen production in a two-step process. The overall hydrogen production when coupling Dark Fermentation and microbial electrolysis was increased up to 13 times when compared to Fermentation alone, achieving a maximum overall hydrogen yield of 1608.6 ± 266.2 mLH2/gCODconsumedand a maximum of 78.5 ± 5.7% of COD removal. These results show that Dark Fermentation coupled with microbial electrolysis is a highly promising option to maximize the conversion of agro-industrial wastewaters and by-products into bio-hydrogen.
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Potentialities of Dark Fermentation effluents as substrates for microalgae growth: A review
Process Biochemistry, 2016Co-Authors: Violette Turon, Eric Trably, Eric Fouilland, Jean-philippe SteyerAbstract:Abstract In recent years, coupling bacterial Dark Fermentation (DF) and heterotrophic cultivation of microalgae (HCM) has been pointed out as a promising sustainable approach for producing both gaseous and liquid biofuels. Complex organic waste and effluents that are not susceptible to be directly degraded by microalgae are first converted into volatile fatty acids (VFAs) and hydrogen by DF. In this work, the feasibility of using DF effluents to sustain HCM has been thoroughly reviewed and evaluated. Promising perspectives in terms of microalgae biomass and lipids production are proposed and can be extended as guidelines to promote HCM whatever the organic waste used. Abiotic and biotic factors from DF effluents that promote or inhibit microalgae growth are discussed as well as the use of unsterile DF effluents. Overall, the microalgae growth is favored on effluents containing high acetate concentration (>3 g L −1 ), with a high acetate:butyrate ratio (>2.5), and when pH is strictly controlled. At a low acetate:butyrate ratio ( 10 g L −1 ), a low substrate:microalgae ratio and the presence of light appear to enhance microalgae growth. Butyrate content appears to be a key factor when coupling DF/HCM since high butyrate concentration inhibits the microalgae growth.
Jens Ejbye Schmidt - One of the best experts on this subject based on the ideXlab platform.
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effect of total solid content and pretreatment on the production of lactic acid from mixed culture Dark Fermentation of food waste
Waste Management, 2018Co-Authors: Ahasa Yousuf, Juanrodrigo Bastidasoyanedel, Jens Ejbye SchmidtAbstract:Food waste landfilling causes environmental degradation, and this work assesses a sustainable food valorization technique. In this study, food waste is converted into lactic acid in a batch assembly by Dark Fermentation without pH control and without the addition of external inoculum at 37 °C. The effect of total solid (TS), enzymatic, and aeration pretreatment was investigated on liquid product concentration and product yield. The maximum possible TS content was 34% of enzymatic pretreated waste and showed the highest lactic acid concentration of 52 g/L, with a lactic acid selectivity of 0.6 glactic/gtotalacids. The results indicated that aeration pretreatment does not significantly improve product concentration or yield. Non-pretreated waste in a 29% TS system showed a lactic acid concentration of 31 g/L. The results showed that enzymatic pretreated waste at TS of 34% results in the highest production of lactic acid.
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recovery of carboxylic acids produced during Dark Fermentation of food waste by adsorption on amberlite ira 67 and activated carbon
Bioresource Technology, 2016Co-Authors: Ahasa Yousuf, Fabian Bonk, Juanrodrigo Bastidasoyanedel, Jens Ejbye SchmidtAbstract:Amberlite IRA-67 and activated carbon were tested as promising candidates for carboxylic acid recovery by adsorption. Dark Fermentation was performed without pH control and without addition of external inoculum at 37°C in batch mode. Lactic, acetic and butyric acids, were obtained, after 7days of Fermentation. The maximum acid removal, 74%, from the Amberlite IRA-67 and 63% from activated carbon was obtained from clarified Fermentation broth using 200gadsorbent/Lbroth at pH 3.3. The pH has significant effect and pH below the carboxylic acids pKa showed to be beneficial for both the adsorbents. The un-controlled pH Fermentation creates acidic environment, aiding in adsorption by eliminating use of chemicals for efficient removal. This study proposes simple and easy valorization of waste to valuable chemicals.
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Dark Fermentation biorefinery in the present and future (bio)chemical industry
Reviews in Environmental Science and Bio Technology, 2015Co-Authors: Juan Rodrigo Bastidas-oyanedel, Fabian Bonk, Mette Hedegaard Thomsen, Jens Ejbye SchmidtAbstract:Dark Fermentation, also known as acidogenesis, involves the transformation of a wide range of organic substrates into a mixture of products, e.g. acetic acid, butyric acid and hydrogen. This bioprocess occurs in the absence of oxygen and light. The ability to synthesize hydrogen, by Dark Fermentation, has raised its scientific attention. Hydrogen is a non-polluting energy carrier molecule. However, for energy generation, there is a variety of other sustainable alternatives to hydrogen energy, e.g. solar, wind, tide, hydroelectric, biomass incineration, or nuclear fission. Nevertheless, Dark Fermentation appears as an important sustainable process in another area: the synthesis of valuable chemicals, i.e. an alternative to petrochemical refinery. Currently, acetic acid, butyric acid and hydrogen are mostly produced by petrochemical reforming, and they serve as precursors of ubiquitous petrochemical derived products. Hence, the future of Dark Fermentation relies as a core bioprocess in the biorefinery concept. The present article aims to present and discuss the current and future status of Dark Fermentation in the biorefinery concept. The first half of the article presents the metabolic pathways, product yields and its technological importance, microorganisms responsible for mixed Dark Fermentation, and operational parameters, e.g. substrates, pH, temperature and head-space composition, which affect Dark Fermentation. The minimal selling price of Dark Fermentation products is also presented in this section. The second half discusses the perspectives and future of Dark Fermentation as a core bioprocess. The relationship of Dark Fermentation with other (bio)processes, e.g. liquid fuels and fine chemicals, algae cultivation, biomethane–biohythane–biosyngas production, and syngas Fermentation, is then explored.
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converting the organic fraction of solid waste from the city of abu dhabi to valuable products via Dark Fermentation economic and energy assessment
Waste Management, 2015Co-Authors: Fabian Bonk, Juanrodrigo Bastidasoyanedel, Jens Ejbye SchmidtAbstract:Abstract Landfilling the organic fraction of municipal solid waste (OFMSW) leads to greenhouse gas emissions and loss of valuable resources. Sustainable and cost efficient solutions need to be developed to solve this problem. This study evaluates the feasibility of using Dark Fermentation (DF) to convert the OFMSW to volatile fatty acids (VFAs), fertilizer and H 2 . The VFAs in the DF effluent can be used directly as substrate for subsequent bioprocesses or purified from the effluent for industrial use. DF of the OFMSW in Abu Dhabi will be economically sustainable once VFA purification can be accomplished on large scale for less than 15 USD/m 3 effluent . With a VFA minimum selling price of 330 USD/t COD , DF provides a competitive carbon source to sugar. Furthermore, DF is likely to use less energy than conventional processes that produce VFAs, fertilizer and H 2 . This makes DF of OFMSW a promising waste treatment technology and biorefinery platform.
