Producing Biohythane from Urban Organic Wastes

This study investigated the advantages of the anaerobic codigestion process of two urban organic waste: the organic fraction of municipal solid wastes and the waste activated sludge produced during biological wastewater treatment. In particular, a comparison between mono and double stage anaerobic digestion for biogas and biohythane (hydrogen and methane) production, respectively, was conducted at thermophilic conditions in a pilot scale rig with a hydraulic retention time of 20 days. Considering yields, the specific gas productions for the single stage process was 490 l biogas per kg TVS fed to the system while in the two stage process hydrogen and methane productions reached average values of 24 LH2 and 570 LCH4 per kg VS fed to the system, respectively. Obtained biohythane, after upgrading, is particularly valuable for the automotive sector contributing to improve the combustion engine performance and to reduce the contaminants emissions in the atmosphere.