Enhancement of Cassava Rhizome Gasification Using Mono-Metallic Cobalt Catalysts

Abstract

This paper proposed cobalt catalysts for the in-situ catalytic gasification of cassava rhizome which represented an important stage in the production of hydrogen-rich gas that suitable for internal combustion and direct-fired industrial gas turbine. The study focused on the comparison of syngas (synthesis gas) production from non-catalytic air-gasification of the cassava rhizome at temperatures from 873 - 1073K, the equivalence ratio (ER) of 0.2-0.4, and continuously feed rate of 30minutes to the catalytic gasification where the cassava rhizome was mixed with 12Co/a-Al2O3 catalyst. The gas yields, hydrogen-carbon conversions and lower heating value (LHV) were compared. The yields of gas products, char and tar for non-catalytic case were 76%, 8.6% and 15%, respectively. Addition of 12Co/a-Al2O3 catalyst improved the gas product yields to 81% while char and tar were reduced to 10% and 8.5%, respectively. With 12Co/a-Al2O3 catalyst, the highest hydrogen and carbon conversions to H2 and CO were 4% and 15% more than non-catalytic runs. The lower heating value (LHV) of producer gas was 8.11MJ/m3 compared to the non-catalytic case LHV of only 4.12MJ/m3. The results indicated that 12Co/a-Al2O3 catalyst with reaction temperature of 1073K and ER of 0.4 yielded high tar reducing performance during air-gasification of the cassava rhizome.