Jetting pre-oxidation fluidized bed gasification process for caking coal: Fundamentals and pilot test

A new jetting pre-oxidation fluidized bed gasification (JPFBG) process, mainly consisting of jetting pre-oxidation zone and char gasification zone, has been proposed and developed by Institute of Process Engineering (IPE), Chinese Academy of Sciences (CAS) to utilize cohesive washing middling coal effectively for fuel gas production and thus replacing the valuable coke oven gas. This article is devoted to summarizing the results obtained in the fundamental studies and a pilot plant. The fundamental studies conducted on an externally heated laboratory JPFB gasification setup demonstrated that the appropriate operating conditions for the pre-oxidation zone and the char gasification zone were at temperature of 950 °C with an excessive air ratio (ER) of about 0.13, and at temperature of 1000 °C with an ER of 0.17 and a mass ratio of steam to coal of 0.09, respectively. Based on these condition data, an autothermal pilot system with a treating capacity of 150 kg/h for strong cohesive coal was built and tested to demonstrate the JPFB gasification process. Keeping the temperatures of the pre-oxidization zone and char gasification zone at about 950 °C and 1000 °C respectively, the higher heating value of the produced fuel gas was close to 4000 kJ/N m3. The obtained typical results from the continuously steady operations of the pilot plant fully verified the technical feasibility and clarified the technical features of the tested new JPFB gasification process.