Development of hot gas clean-up system for IGCC

摘要

The syngas generated at the gasifier in the Integrated Gasification Combined Cycle (IGCC) is reductive gas, so the sulfur in the fuel is reduced to H2S and COS. Many wet types of gas clean up system using liquid solvents are commercially available. However, we have been developing the higher performance and efficient system using oxide metals sorbent, that we call Hot Gas Clean Up system (HGCU system) with fluidized bed reactors. Therefore, we have participated Yubari and Nakoso pilot plant projects as the national project to develop and establish the HGCU system and it's technology to realize lower environmental emission and high thermal efficiency. The test results of those pilot plants are very good performance and we have confirmed that the HGCU system is applicable to IGCC plant. Those pilot plants have used the iron oxide (crashed iron ore) as the desulfurization sorbent. However, the iron oxide sorbent can not get high desulfurization performance for the gas containing high moisture (about 10 vol% and over) and can not keep sever environmental requirement in the near future. Thus, we have developed the HGCU system using zinc oxide sorbent that is expected higher desulfurization performance. We have carried out many tests at our Coal Gasification Test facility (CGT test plant). We achieved 20 ppmV total sulfur concentration of desulfurized gas and confirmed that the HGCU system has high performance and reliability. We think that the environmental requirements have become more stringent. The IGCC power plant with the HGCU system is expected to be realized in the near future in view of its high efficiency and environmental superiority.