Development of a novel 2-stage entrained flow coal dry powder gasifier

Coal-fired gasifiers are the key technology for clean power generation and coal chemical process. This paper presents a 2-stage entrained flow dry powder gasifier in which coal is entrained into the lower chamber burner with oxygen and steam to raise the temperature of the crude gas up to 1700 degrees C. The lower chamber is linked to the upper gasification chamber through a middle throat, where additional coal and steam is fed to cool down the slag to less than 900 degrees C for deslagging from the lower chamber bottom. Various coals have been characterized and gasified with this 2-stage entrained flow dry powder gasifier and comparisons made with single stage gasifiers. The results show that the 2-stage gasifier is suitable for a broad range of coal varieties and gives carbon conversion up to 98.9% with cold syngas efficiency of 83.2% at a pressure of 3.0 MPa, while the oxygen and coal consumption are lower than with the single stage gasifier. (C) 2013 Elsevier Ltd. All rights reserved.