Start-up and operation of continuous stirred-tank reactor for biohydrogen production from restaurant organic solid waste

The hydrogen production from a variety of substrates, including organic solid waste (OSW), has been studied at different organic loading rate (OLR), finding different behavior on the hydrogen production rate (HPR) that can be related to the particular waste characteristics and particular operational conditions. The objective of this study was to evaluate the startup and operation of a continuous stirred-tank reactor (CSTR) to generate hydrogen from food waste applying different OLR in order to determine the operational conditions to obtain the maximal HPR. Three OLR, controlled via the influent flow rate, were studied: 19, 38 and 57 gVS/L-reactor/d. It was found that the OLR has an influence on the hydrogen production in the CSTR. The increase of OLR results in a decrease of COD removal, protein removal, and hydrogen yield (YH2). The highest HPR (19.8 mmol H-2/L-reactor/d) and YH2 (0.6 mmol H-2/gVS) were obtained at the OLR of 37.1 and 19.8 gVS/L-reactor/d, respectively. The H-2 percentage in biogas had variations between 25 and 55% independently of the OLR. The VS and COD removal efficiencies were 51 +/- 9% and 27 +/- 9% respectively. Acetic acid was the principal VFA produced during the CSTR operation. Copyright (c) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.