Hydrogen production from residual biomass via air-steam gasification for a bioenergy-based economy in Sicily

This work aims at evaluating the potential impact of hydrogen production in Sicily by citrus peel air-steam gasification. The thermochemical behavior of such feedstock was evaluated in a previous work by means of a bench-scale fluidized bed reactor operate at different temperature and steam to biomass ratios. A virtual scale-up of the gasification system was developed in order to assess the combined hydrogen and power production potential. The downstream processes of syngas, i.e. hydrogen separation through Pressure Swing Adsorption (PSA) and off-gas combustion in engines for power production, were simulated considering the efficiencies reported in literature and datasheets. The results of this study show that, depending on the gasifier operating conditions, from 1,000 to 1,414 t/year of hydrogen can be produced by exploiting the totality of available citrus peel in Sicily (33,000 t/year). It has been estimated that from 927 to 15,900 MWh/year of electricity can be produced, in combination with hydrogen, by internal combustion engines and exported to the national grid, while the recovered heat may be used for the citrus peel drying.