Pyrolysis of long flame coal under steam atmosphere in a fluidised-bed reactor

Steam pyrolysis is a technology defined as the thermal decomposition of coal through the application of heat in the presence of water vapour provided as a pyrolysis atmosphere. In this work, the steam pyrolysis of long flame coal particles in a fluidised-bed reactor was investigated in detail. It focuses on evaluating factors that may impose possible effect on the yields and properties of final products in terms of type of sweeping gas, coal particle size, pyrolysis time, temperature and water flow rate etc. It is observed that water vapour is a reactive agent and involved in the reduction/reforming reaction of CmHn hydrocarbons and coal gasification. It accelerates the structure destruction, diffusion and decomposition of hydrocarbons, especially for those compounds with high molecular weight. The optimal steam pyrolysis conditions for coal particles with the range of 0.5-2.8 mm are at 600°C of pyrolysis temperature and with 15 minutes of pyrolysis time. [Received: October 7, 2015; Accepted: March 2, 2015]