MODELING AND SIMULATION STUDIES OF HYBRID GASIFIER USING VARIOUS FEEDSTOCKS (FUELS)

Coal gasification is one of the focus to redress the energy issue in the world. Significant efforts have been directed towards the development of coal/biomass gasifier to replace traditional combustion systems. Detailed study of the process for a large variety of feedstocks and designs is possible through modeling and simulation at manageable costs. This paper addresses the development of Steady state simulation model for gasification using Aspen Plus with a particular emphasis on the influence of process operating conditions on synthesis gas composition, high heating value and cold gas efficiency with various fuels. The Hybrid gasifier has been modeled in three stages. The simulation results are compared with the experimental results obtained through hybrid gasifier. The performance of the simulated gasifier has been compared using experimental data for Coal and Auto Shredder Waste (Used Tyres). In the simulation study, the operating parameters like Temperature, Equivalence Ratio (ER), Feed Moisture Content and Steam/Feed Injection Ratio have been varied over wide range as 400-1400°C, 0.1-0.9, 5-40%, and 0.05-0.4 respectively to investigate their effect on syngas composition, High Heating Value (HHV) and Cold Gas Efficiency (CGE). It was observed that Auto Shredder Waste has maximum value of CGE (34%) at an ER of 0.28. Coal shows highest value of CGE 55% at an ER of 0.31. Among all feed stocks considered coal shows best gasification characteristics regarding Cold Gas Efficiency. Temperature increases the production of CO and H2. Increasing ER decreases the production of CO and H2 which decreases the CGE. Feed moisture content is an important parameter affecting the heating value of the gas. Steam injection favors hydrogen production. The study has been instrumental to identify the preferred operating parameters of gasifier under consideration.