Design and operation of pilot plant for CO 2 capture from IGCC flue gases by combined cryogenic and hydrate method

Abstract

This project is a trial conducted under contract with CO 2CRC, Australia of a new CO 2 capture technology that can be applied to integrated gasification combined cycle power plants and other industrial gasification facilities. The technology is based on combination of two low temperature processes, namely cryogenic condensation and the formation of hydrates, to remove CO 2 from the gas stream. The first stage of this technology is condensation at −55 °C where CO 2 concentration is expected to be reduced by up to 75 mol%. Remaining CO 2 is captured in the form of solid hydrate at about 1 °C reducing CO 2 concentration down to 7 mol% using hydrate promoters. This integrated cryogenic condensation and CO 2 hydrate capture technology hold promise for greater reduction of CO 2 emissions at lower cost and energy demand. Overall, the process produced gas with a hydrogen content better than 90 mol%. The concentrated CO 2 stream was produced with 95–97 mol% purity in liquid form at high pressure and is available for re-use or sequestration. The enhancement of carbon dioxide hydrate formation and separation in the presence of new hydrate promoter is also discussed. A laboratory scale flow system for the continuous production of condensed CO 2 and carbon dioxide hydrates is also described and operational details are identified.