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Kumar G.,Feng Chia University | Lay C.-H.,Tampere University of Technology | Chu C.-Y.,Feng Chia University | Wu J.-H.,Stone and Resource Industry Randnter | And 2 more authors.
International Journal of Hydrogen Energy

This study aimed to optimize the hydrogen production from various seed sludges (two kinds of sewage sludges (S1, S2), cow dung (S3), granular sludge (S4) and effluent from condensed soluble molasses H 2 fermenter (S5)) and enhancement of hydrogen production via heat treatment for substrate and seed sludge by using the solid residues of biodiesel production (BDSR). Two batch assay tests were operated at a biodiesel solid residue concentration of 10 g/L, temperature of 55 °C and an initial cultivation pH of 8. The results showed that the peak hydrogen yield (HY) of 94.6 mL H 2/g volatile solid (VS) (4.1 mmolH 2/g VS) was obtained from S1 when substrate and seed sludge were both heat treated at 100 °C for 1 h. However, the peak hydrogen production rate (HPR) and specific hydrogen production rate (SHPR) of 1.48 L H 2/L-d and 0.30 L H 2/g VSS-d were obtained from S2 without any treatment. The heat treatment was found to increase the HY in both the cases of sewage sludges S1 and S2.The HY of 89.5 mL H 2/g VS (without treatment) was increased to 94.6 mL H 2/g VS and 82.6 mL H 2/g VS (without treatment) was increased to 85.7 mL H 2/g VS for S1 and S2. The soluble metabolic product (SMP) analysis showed that the fermentation followed mainly acetate-butyrate pathway with considerable production of ethanol. The total bioenergy production was calculated as 2.8 and 2.9 kJ/g VS for favorable hydrogen and ethanol production, respectively. The BDSR could be used as feedstock for dark fermentative hydrogen production. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Source

Chuang Y.-S.,Feng Chia University | Lay C.-H.,Feng Chia University | Sen B.,Agharkar Research Institute | Chen C.-C.,ChungChou Institute of Technology | And 4 more authors.
International Journal of Hydrogen Energy

The effects of substrate concentration and temperature on fermentative hydrogen production from Eichhornia crassipes using pig slurry microflora were studied, and the optimal values for maximum biohydrogen production were determined in batch experiments. Hydrogen and methane yield (HY and MY) and production rate (HPR and MPR) were evaluated at various E. crassipes concentrations (10-80 g/L) and incubation temperatures (25, 35, 45, 55, and 65 °C). Hydrogen and methane production were observed during the E. crassipes fermentation without any nutrients addition, and were dependent on E. crassipes concentrations. Maximum HPR (38.2 mmol H2/L/d) and MPR (29.0 mmol CH4/L/d) were obtained at E. crassipes concentration of 40 g/L and 80 g/L, respectively. Monod model and modified Andrew model were used to fit the hydrogen production rate data. Modified Andrew model could describe better the effects of substrate concentration on hydrogen production rate (greater R 2 value). Maximum HPR (221.3 mmol H2/L/d) and MPR (24.4 mmol CH4/L/d) were obtained at 45 and 55 °C, respectively. These values were ca. 1105 and 18 folds higher than the HPR (0.2 mmol H 2/L/d) and MPR (7.3 mmol CH4/L/d) at 25 °C, probably due to increased hydrolysis of E. crassipes at higher temperatures. Ratkowsky model could best describe the progress of hydrogen and methane production potential and rate (R2 > 0.9). The optimum E. crassipes concentration and incubation temperature were determined as 47.8 g/L and 62.5 °C, respectively for maximum hydrogen and methane production. Biohydrogen and biomethane yields from E. crassipes were 31.3 GJ/ha/y and 853.9 GJ/ha/y, respectively, with a total CO2 emission reduction from 15.2 to 23.7 tons. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Source

Lu H.-Y.,National Ilan University | Lin C.-S.,Stone and Resource Industry Randnter | Lee S.-C.,Stone and Resource Industry Randnter | Ku M.-H.,Stone and Resource Industry Randnter | And 3 more authors.

Continuing our previous work, in which we analyzed the performance of Selemion ASV membrane (Asahi Glass Engineering) used to reduce the content of sulfate ions in concentrated brine from deep sea water (DSW) via a laboratory-scale electrodialysis (ED) apparatus, we analyze in situ the osmosis effect for Selemion CMV/ASV module (Asahi Glass Engineering) during ED process in this work. By recording the liquid volume in both concentrate and dilute tanks, it is found possible that the water flow across the membranes due to the osmosis effect could be estimated through the measurement of ionic volume flow. The analysis reveals that, when a higher DC voltage is applied, water flows from the concentrate to the dilute at initial stage of ED process, and it flows reversely at later stage; however if a lower DC voltage is applied, water flows from the concentrate to the dilute during whole ED process. Via a carpet searching process, a reasonable effective dynamic hydration number for hydrated ions is found as 3.5, and the water permeability of CMV/ASV module is estimated as 0.25214. cm/h. © 2011 Elsevier B.V. Source

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