Catalytic Adaro Coal Gasification Using Dolomite and Nickel as Catalysts

Abstract

Integrated Gasification Combined Cycle (IGCC) is an Advanced Clean Coal Technology and can be used as an option for future TNB coal-fired power plant. The implementation of this technology is expected to reduce Green House Gas emissions (eg. CO2), which caused global warming. However, there are several problems in IGCC system, including low carbon conversion and low efficiency in gasifier. Previous studies had shown that higher carbon conversion and efficiency only can be achieved at higher temperature of 900-1000oC. In this study, we had increased the carbon conversion and gasifier efficiency for Adaro coal gasification process using catalyst as in-bed material at lower operating temperature of 700-800oC. Dolomite and nickel with high catalytic activity are selected as catalysts. These catalysts will enhance tar cracking and production of syngas. Furthermore, dolomite is also cheap and abundantly available in Malaysia. Coal catalytic gasification tests were conducted using TNBR Pilot Scale Gasification Plant (PSGP). Adaro coal (100%), Adaro coal:dolomite (80:20) and Adaro coal:dolomite:nickel (90:9:1) mixtures were gasified using PSGP. The results showed that the presence of dolomite had increased Carbon Conversion (CC) and Gasification Efficiency (GE) about 3.1% and 30.7% respectively, compared to Adaro coal gasification. While, the presence of dolomite and nickel for Adaro coal:dolomite:nickel (90:9:1) gasification, had increased CC and GE about 9.5% and 16.4% compared to Adaro coal gasification. Lower increasing of the GE with the presence of nickel is expected due to the deactivation (poison) effect of H2S towards nickel during the gasification process.