(621cg) Effect of Pyrolysis Temperature on the Gasification Reactivity of Solvent Extracted Ash-Free Coals and Insoluble Residual Coals

Gasification of coal to syngas has gained popularity, thanks to use of cheap and abundant coal. Coal that is composed of thousands of different macromolecules experiences thermal decomposition in most of the applications, breaking the linking aliphatic bonds, releasing volatile matters, and rearranging the aromatic matrix. Therefore, the reactivity of the chars is different from the parent coals, and which are significantly influenced by the heating temperature. In order to investigate the effect of pyrolysis on the gasification reactivity, ash-free coal (AFC) that is produced by solvent extraction of Indonesian lignite, insoluble residual coal (RE), and original raw coal (RA), are pyrolyzed at 300 – 900 ºC with 100 ºC interval and then gasified under steam. The gasification rate of the different chars of the same origin prepared below 700 ºC is generally comparable with each other, and it drops for the chars pyrolyzed above 800 ºC. The gasification behavior of AFC and RE varies depending on the polarity of the extraction solvent. The steam gasification and associated CO to CO₂ conversion of the AFCs are significantly enhanced by K₂CO₃ catalyst, indicating catalytic coal gasification at mild condition as well as repeated use of the catalyst is achievable when AFC is gasified as feedstock.