Conversion of agricultural waste mixtrues (tea, tobacco and sunflower seeds) to gaseous product in presence of heterogenous catalyst by thermochemical method

The aim of the study is to obtain hydrogen-rich gas by catalytic thermochemical conversion methods from waste agricultural mixtures (biomass). In this study, sunflower seed pulp, tea and tobacco wastes were mixed in equal proportions. Catalysts were synthesized by the impregnation method using different clay supports (bentonite and kaolin) at different Ni ratios (10, 20, 30%) in order to use in experimental studies and characterized by TGA, FT-IR, XRD, XRF, SEM and BET analysis methods. The activity of the catalysts was tested in gasification, liquefaction and steam reforming. In the gasification studies, the effect of reaction temperature (650-850 °C), reaction time (15-30 min), and the effects of different catalysts on the gas product distribution were investigated. The highest H2 yield was obtained by using 20% 30Ni/K-Kao for 15 minutes at 650 °C as 6,86 mol H2/kg biomass. The gas product was obtained from biomass by applying two-stage processes, liquefaction and steam reforming. The effect of catalyst type (K-Bent, 30Ni/K-Bent, KKao and 30Ni/K-Kao) was investigated in liquefaction (at 350 °C, 60 min, 50/1 water/biomass and 10% catalyst constant conditions). The liquid product yield was achieved as 85% by using 30Ni/K-Bent catalyst. The effect of the reaction temperature (600-850 °C) on the steam reforming of the liquid product (24/3 water/liquid product ratio and 0,5 g catalyst at constant conditions) was investigated. The highest H2 yield was obtained as 56,52 mol H2/kg liquid product at 850 °C using 30Ni/K-Bent catalyst.