EXPERIMENTAL AND SIMULATION STUDIES OF CORN KERNEL GASIFICATION IN A DOUBLE AIR STAGE DOWNDRAFT REACTOR

摘要

Biomass gasification is the devolatilization and incomplete combustion of biomass resulting in the production of a combustible gas mixture including carbon monoxide (CO), hydrogen (H_2) methane (CH_4), and traces of other hydrocarbons (C_nH_m), and referred to as producer gas. Producer gas can be cleaned and then used in various engines or can be converted to various biofuels. This paper presents an experimental and simulation-based evaluation of producer gas quality resulting from corn kernel gasification in a two-stage downdraft gasifier. Test conditions were selected, based on the results of previous studies, to yield high conversion efficiency and low tar production. Experimental tests were performed with an air flow of 25 Nm~3/h and with 80% of the air supplied to the first gasification stage. Simulations based on a chemical and thermal equilibrium model were carried out to examine the effect of equivalence ratio (ER) changes. Both the experimental and modelling results show that using a two-stage air supply leads to a significant reduction in the tar content of the producer gas, while maintaining a high gasification efficiency.