EXPERIMENTAL INVESTIGATIONS ON AIR GASIFICATION OF COFFEE HUSK
Gasification of biomass is gaining prominence as preferred energy technology. Biomass gasification provides the opportunity for converting renewable biomass feedstock into a mixture of gases consisting of hydrogen, carbon monoxide, methane and carbon-dioxide, commonly known as producer gas. Producer gas can be used for hydrogen generation and as a fuel for combined heat and power (CHP) applications. Considering the Indian context, abundant biomass resources including various agricultural and forestry residues are locally available. Among the various biomasses available, the feasibility of coffee husk as a feedstock for gasification has been investigated experimentally. The feasibility of air gasification of coffee husk as a feedstock was investigated in a bubbling fluidised bed gasifier in terms of its gas yield (mainly hydrogen), gas composition and heating value. During the operation, the temperature is varied in the range, 680 °C to 780 °C. Air and biomass feed rates were fixed based on the equivalence ratio selected. In the experimental investigation, it is found that hydrogen yield is 20.1 g/kg biomass at a temperature of 780 °C and Equivalence Ratio of 0.24. The gas yield and LHV are 1.31 Nm3/kg of biomass and 5.88 MJ/Nm3, respectively.