Species – Transport CFD model for the gasification of rice husk (Oryza Sativa) using downdraft gasifier

Abstract

The biomass as a source of energy is increasing globally due to environmental pollution and shortage of fossil fuels. The process of converting the biomass into useful energy is known as gasification. The implementation of gasification technology in remote areas needs more theoretical and experimental studies. Several models have been proposed to explain the geometrical parameters and the optimization of gasification process. Hence, the paper presents the numerical simulation of the gasifier using the species-transport model in CFD by incorporating all the zones of the gasifier and the experimental studies are conducted on a 40kW downdraft gasifier with rice husk (Oryza Sativa) available in remote villages situated in South India. The factors affecting the producer gas such as equivalence ratio, gas composition, higher heating value and the temperature distribution inside the gasifier have been studied. Both the studies established that the higher heating value and the producer gas composition are 5.19MJ/Nm3 with CO–22%, CH4–1.7%, CO2–8%, H2–13% and N2–40.1% respectively. Also, it is predicted that the zone temperatures are maximum when ER is 0.30.