Catalytic effects of Na2CO3 additive on coal pyrolysis and gasification.

Catalytic pyrolysis and gasification characteristics of coal using Na 2 CO 3 as a catalyst were studied in a high-frequency furnace and thermogravimetric analyzers (TGA), respectively. Interactions of Na 2 CO 3 with carbon at both pyrolysis and gasification phases were observed by in-situ heating stage microscope. The effects of pyrolysis temperature (650–800 °C) and catalyst loading amount (0–15 wt.%) on the associated pyrolysis and gasification processes were investigated. The results show that, H 2 and CO are the main pyrolysis gas products and the yields of these two gas increase with the increasing of Na 2 CO 3 in the range of 0–15 wt.%. The in-situ heating stage experiments indicated that one main gasification reaction form was observed for Shenfu char samples. Most of SF char particles reacted with CO 2 in the form of shrinking core mode without cracking, and certain particles presented fragmentation phenomenon in the reaction process. There is an optimal loading amount of Na 2 CO 3 for the best catalytic gasification effect of Shenfu bituminous char, while Na 2 CO 3 does not reach the saturation amount for the catalytic gasification of Zunyi anthracite coal. The activation energy of catalytic Shenfu coal gasification with 10 wt.% Na 2 CO 3 is 31.5 kJ mol − 1 less than that of non-catalytic coal gasification, which indicates that Na 2 CO 3 can improve the kinetics of coal gasification with CO 2 . [ABSTRACT FROM AUTHOR]