Hydrogen production from rotten dates by sequential three stages fermentation

This study was devoted for H-2 production from rotten fruits of date palm (Phoenix dactylifera L.) by three fermentation stages. A facultative anaerobe, Escherichia coli EGY was used in first stage to consume O-2 and maintain strict anaerobic conditions for a second stage dark fermentative H-2 production by the strictly anaerobic Clostridium acetobutylicum ATCC 824. Subsequently, a third stage photofermentation using Rhodobacter capsulatus DSM 1710 has been conducted for the H-2 production. The maximum total H-2 yield of the three stages (7.8 mol H-2 mol(-1) sucrose) was obtained when 5 g L-1 of sucrose was supplemented to fermentor as rotten date fruits. A maximum estimated cumulative H-2 yield of the three stages (162 LH2 kg(-1) fresh rotten dates) was estimated at the (5 g L-1) sucrose concentration. These results suggest that rotten dates can be efficiently used for commercial H-2 production. The described protocol did not require addition of a reducing agent or flashing with argon which both are expensive. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.