Abstract:
Several reports have demonstrated the feasibility of hydrogen production by dark
fermentation (DF). However, most reports had resorted to mesophilic or thermophilic
conditions to increase hydrogen yield, overlooking the energy input to the process and
hence, loss of net energy gain. For net positive energy gain, energy input to the process
should be minimized and additional energy should be harvested from the aqueous end
products of DF. Our previous study presented an approach to assess the potential for net
energy gain from the hydrogen produced by DF, and from the end products of DF via
anaerobic digestion (AD) or microbial fuel cells (MFC). In this study, that approach is
extended to identify the most promising process configuration and operating conditions to
maximize net energy gain possible from liquid and particulate organic wastes. Based on
this analysis, DF followed by MFC appears to result in higher net energy gains.
