MODELING AND SIMULATION OF A DOWNDRAFT RICE HUSK GASIFIER

The behaviour of a downdraft rice husk gasifier of diameter 200 mm and a height 940 mm has been studied. The gasification rate was varied in the range 1.8-4.3 x 10(-2) kg/m2s. The air velocity was varied in the range 0.032-0.099 m/s. The producer gas obtained from the gasifier ha s a calorific value in the range 3240-4382 kJ/m3. A set of theoretical kinetic equations on the assumption of nonequilibrium conditions has been developed and solved numerically. The simulated temperature profi le and outlet gas composition have been compared with those obtained f rom experimental runs. The model developed from a mechanistic approach is found to explain the behaviour of the present system appreciably w ithin the range of variables studied.