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The effect of organic loading rate and retention time on hydrogen production from a methanogenic CSTR

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Original languageEnglish
Pages (from-to)8952-8957
Number of pages6
JournalBioresource Technology
Issue number19
Publication statusPublished - Oct 2011
Publication typeA1 Journal article-refereed


The possibility of shifting a methanogenic process for hydrogen production by changing the process parameters viz., organic loading rate (OLR) and hydraulic retention time (HRT) was evaluated. At first, two parallel semi-continuously fed continuously stirred tank reactors (CSTR) were operated as methanogenic reactors (M1 and M2) for 78days. Results showed that a methane yield of 198-218L/kg volatile solids fed (VS fed) was obtained when fed with grass silage at an OLR of 2kgVS/m 3/d and HRT of 30days. After 78days of operation, hydrogen production was induced in M2 by increasing the OLR from 2 to 10kgVS/m 3/d and shortening the HRT from 30 to 6days. The highest H 2 yield of 42L/kgVS fed was obtained with a maximum H 2 content of 24%. The present results thus demonstrate that methanogenic process can be shifted towards hydrogen production by increasing the OLR and decreasing HRT.


  • Grass silage, Hydrogen, Methane, Shifting, VFA