کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1281033 | 1497615 | 2010 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Biohydrogen production from beet molasses by sequential dark and photofermentation Biohydrogen production from beet molasses by sequential dark and photofermentation](/preview/png/1281033.png)
Biological hydrogen production using renewable resources is a promising possibility to generate hydrogen in a sustainable way. In this study, a sequential dark and photofermentation has been employed for biohydrogen production using sugar beet molasses as a feedstock. An extreme thermophile Caldicellulosiruptor saccharolyticus was used for the dark fermentation, and several photosynthetic bacteria (Rhodobacter capsulatus wild type, R. capsulatus hup− mutant, and Rhodopseudomonas palustris) were used for the photofermentation. C. saccharolyticus was grown in a pH-controlled bioreactor, in batch mode, on molasses with an initial sucrose concentration of 15 g/L. The influence of additions of NH4+ and yeast extract on sucrose consumption and hydrogen production was determined. The highest hydrogen yield (4.2 mol of H2/mol sucrose) and maximum volumetric productivity (7.1 mmol H2/Lc.h) were obtained in the absence of NH4+. The effluent of the dark fermentation containing no NH4+ was fed to a photobioreactor, and hydrogen production was monitored under continuous illumination, in batch mode. Productivity and yield were improved by dilution of the dark fermentor effluent (DFE) and the additions of buffer, iron-citrate and sodium molybdate. The highest hydrogen yield (58% of the theoretical hydrogen yield of the consumed organic acids) and productivity (1.37 mmol H2/Lc.h) were attained using the hup− mutant of R. capsulatus. The overall hydrogen yield from sucrose increased from the maximum of 4.2 mol H2/mol sucrose in dark fermentation to 13.7 mol H2/mol sucrose (corresponding to 57% of the theoretical yield of 24 mol of H2/mole of sucrose) by sequential dark and photofermentation.
Journal: International Journal of Hydrogen Energy - Volume 35, Issue 2, January 2010, Pages 511–517