Estimating the Effect of Biomass to Catalyst Ratio on the Bio-oil and Char Yield in the Pyrolysis of Spent Coffee Grounds
Abstract
Spent coffee grounds as a biomass is pyrolyzed in a fixed bed reactor under varying ratios of biomass to catalyst. Three different types of catalysts were studied. The pyrolysis temperature and nitrogen flowrate were maintained constant at 600 oC and 1.5 mL/min. The catalytic pyrolysis of biomass was performed with various amounts of FeO, ZnO and Al2O3 catalysts (2, 3, 4, and 5 wt.%). The addition of catalysts resulted in decreased bio-oil and char yield while gas yield was increased. The catalysts addition increased the quality of bio-oil in terms of calorific value, production of less oxygenated compounds and increased hydrocarbon distribution. It was observed that for biomass to catalyst ratio of 13:2, the maximum bio-oil yield was obtained with all the catalyst while maximum gas yield was obtained at the biomass to catalyst ratio of 10:5. This paper highlights the potential of using waste biomass as a source of renewable energy.