Hydrogen production from coffee wastes

In this study, thermal and catalytic hydrogen production was studied by using steam gasification using coffee waste, coffee waste chars obtained from pyrolysis at 300 ˚C and 500 ˚C and their blends as biomass. It was also aimed the decomposition of the tar which is an unwanted by-product of steam gasification. The steam gasification was carried out in a vertical fixed double bed reactor. In the all experiments, the biomass bed (upper bed) was fixed at 850 ˚C. In the thermal experiments, the temperature of catalyst bed (bottom bed) was varied between 600 and 850 °C and the effect of bottom bed temperature on the H2 yield and tar decomposition was investigated. In catalytic experiments, bottom bed temperature was fixed at 700 ˚C and the effect of catalysts (dolomite, red mud and mussel shell) on tar decomposition was investigated. In the gasification of blends, the synergistic effect between biomass and biochar was investigated. Key words: Biomass, coffee wastes, biochar, catalyst, steam gasification, hydrogen