Techno-economic analysis of dark fermentative hydrogen production from molasses in a continuous mixed immobilized sludge reactor

The techno-economic analysis of dark fermentative hydrogen production from molasses in a novel continuous mixed immobilized sludge reactor was performed. The hydrogen-producing plant was assumed to be built in Hangzhou with lifetime of 10 years. The effect of the working volume (10–50 m3) on the economic performance of hydrogen-producing plant was also investigated. The mass and energy balance of the bioprocess was simulated using Super-Pro Designer. The return on investments increased from −37.2% to 47.3% with scales increasing from 10 m3 to 50 m3. Only the scales of 40 m3 and 50 m3 could get positive benefits with payback periods of 9.7 years and 6.9 years, respectively. The internal rate of return of scales of 40 m3 and 50 m3 were 0.63% and 9.25%, respectively, which meant the hydrogen-producing plant with higher scale (50 m3) would be more economically feasible.