Takahito Yonekawa

Improvements of carbon dioxide capture technology from flue gas

Publisher Summary This chapter discusses that Mitsubishi heavy industries, ltd. (MHI), and Kansai electric power co. (KEPCO) jointly developed the post combustion amine scrubbing technology. KEPCO & MHIs flue gas CO2 recovery process that use proprietary hindered amine with special equipment. The main objective of this chapter is to achieve economical CO2 recovery for enhanced oil recovery (EOR) or storage. It includes the design of large CO2 recovery plant and process optimization for operational cost reduction. Performance of the advanced KEPCO & MHIs flue gas CO2 recovery process is compared to its predecessor process. It concludes that improved heat recovery around CO2 stripper resulted in 15 % reduction of steam requirement for regeneration. Solvent loss is reduced by installing proprietary device at the top of absorber, and structured packing enabled compact tower, to increase flue gas velocity and power reduction of flue gas blower.

Carbon dioxide capture technology for coal fired boiler

Publisher Summary This chapter discusses the consequences of the flue gas impurity removal test obtained by the capture test for CO2 from the flue gas of coal fired boilers. This process is performed using the pilot plant constructed in the Mitsubishi Heavy Industries (MHI) Hiroshima R&D center. This plant has boilers, dust separator, flue gas processing apparatuses, and the desulfurizing system of the wet limestone gypsum method (FGD). The CO2 recovery system is includes a rinse tower to remove sulfur oxides present in the flue gas, a cooling tower to cool the flue gas, an absorbing tower to capture CO2 by “KS-1 solvent,” a water washing tower to recover solvent components accompanying the flue gas from the CO2 absorbing tower, and a regenerating tower to strip CO2 by heating the solvent absorbing CO2 with steam. The purity of the CO2 captured from the flue gas of the coal fired boilers is approx. 99.8 %-dry, which meets the requirement of 95% or higher in purity generally required for CO2EOR. When the concentration of sulfur oxides flowing into the CO2 recovery system is high, the accumulation of heat stable salt, particularly sulfate, increases to cause the deterioration of the solvent. To solve this problem, sulfur oxides must be pre-processed and removed on the downstream side of the CO2 recovery system beforehand.