title: The effect of organic loading rate and retention time on hydrogen production from a methanogenic CSTR.
abstract: 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 78 days. Results showed that a methane yield of 198-218 L/kg volatile solids fed (VS(fed)) was obtained when fed with grass silage at an OLR of 2 kgVS/m³/d and HRT of 30 days. After 78 days of operation, hydrogen production was induced in M2 by increasing the OLR from 2 to 10 kgVS/m³/d and shortening the HRT from 30 to 6 days. The highest H₂ yield of 42 L/kgVS(fed) was obtained with a maximum H₂ content of 24%. The present results thus demonstrate that methanogenic process can be shifted towards hydrogen production by increasing the OLR and decreasing HRT.
authors.affiliation: Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland. outi.m.pakarinen@jyu.fi
authors.forename: O
authors.initials: O
authors.lastname: Pakarinen
authors.forename: P
authors.initials: P
authors.lastname: Kaparaju
authors.forename: J
authors.initials: J
authors.lastname: Rintala
mesh_terms: D019149:Bioreactors; D005387:Finland; D006859:Hydrogen / Q000378:metabolism*; D007700:Kinetics; D008697:Methane / Q000096:biosynthesis*; D012820:Silage; D013997:Time Factors
chemical_list: D006859:Hydrogen; D008697:Methane