Sharif Digital Repository

This article presents a two-dimensional simulation of the coal gasification in tapered fluidized bed gasifier. The effects of tapered angle, gasifier temperature, velocity of gasifying agent, and steam-to-air ratio on the gas compositions, lower heating value (LHV), and higher heating value (HHV) were examined. In order to find the appropriate operating conditions of coal gasification, carbon conversion efficiency (CCE) and cold gas efficiency (CGE) were also explored. It was found that with an increase of the gasifier temperature, CCE and CGE of the tapered gasifier diminishes. Increasing tapered angle results in a decrease of the LHV and HHV of the gas products, whereas the CCE of...