Use of real time gas production data for more accurate comparison of continuous single-stage and two-stage fermentation

► Real-time measurement of biogas composition was used to determine biogas yields. ► An increase in methane yield of 37% was observed using two-stage fermentation. ► Two-stage fermentation could be performed at shorter HRTs and higher OLRs. ► Methane yields from two-stage were greater than those predicted by a BMP test. ► Two-stage fermentation also produces hydrogen, resulting in greater energy yields.