Analysis of Biohydrogen Production Potential from Organic Wastes Generated in Korea

Abstract

Objectives : To mitigate greenhouse gas (GHG) emissions, our country is trying to replace fossil fuel to hydrogen (H2). H2 has higher energy yield (122 MJ/kg) than other energy sources (natural gas, coal, etc.), and is considered a clean fuel that produces only water upon combustion. The water electrolysis using renewable energy is one of the green-H2 producing methods, but its unstable characteristics depending on weather condition impede its practical application. Therefore, to establish green-H2 society, the use of waste and biomass is essential to fulfil the demand.Methods : In this study, we estimated the biohydrogen potential of organic solid wastes: food waste, livestock manure, and sewage sludge, which are the main feedstock of domestic biogas plant. For the H2 generation process, dark fermentation (DF) and steam biogas reforming (SBR) were considered.Results and Discussion : The potential amount of H2 through DF and SBR was 44,000 ton/y and 675,000 ton/y, respectively. The GHG reducing potential was estimated to be 5 million tons CO2-eq/year, but it can be lowered down to 2 million tons CO2-eq/year, considering the energy consumption during H2 generation process. Among the energy potential of produced H2, 7% and 60% is required for H2 production in DF and SBR, respectively.Conclusion The expected biohydrogen production was 718,000 ton/y which can account for about 14% of the domestic H2 production target in 2040 (526 million tons). The main source was livestock manure (86%), and minor fraction was from food waste (10%), and sewage sludge (4%). The GHG reducing potential was estimated to be 2 million tons CO2-eq/year, considering the energy consumption during H2 generation process.