Catalytic Reforming Of Tar Derived From Mild Gasification Of Shengli Lignite

Coal chars were employed to catalyze the in-situ tar reforming reactions during the pyrolysisand gasification of Shengli brown coal in a two-stage quartz reactor at different temperatures. Fourdifferent chars (inactivated char, steam activated char, ammonia water activated char and ammoniagas activated char) as catalysts were prepared. The tar derived from the gasification of Shenglibrown coal under different conditions was collected by cold solvent. In order to clarify the role ofsteam playing in the tar reduction with and without catalysts, pyrolysis at the same conditionswere always carried out for the purpose of comparison. The effect of temperature, heating rate,steam and catalysts on the yield and composition of tar and gas product were investigated under awide range of experimental conditions. Wherein, the compositions of coal tar were characterizedby GC-MS and the composition of gas were tested by GC. Several kinds of techniques were usedto characterize the char catalysts before and after use to provide the mechanism of tar reformingby char catalyst. It was found that char catalysts showed obvious effect on the tar derived from thepyrolysis/gasification of Shengli brown coal. Ammonia gas activated char showed the mostobvious effect on the reforming of gasification coal tar, and a yield decrease of88.72%in thegasification under900℃was achieved comparing with the same condition that no catalyst wasutilized. No compound was detected except trace phenanthrene. The gas product yield wasincreased by5.16%and the content of H2+CO grew from82.90%to83.83%.