A key part of this technology is the removal of CO2 and H2S from the synthetic gas (Syngas) stream by scrubbing with a physical solvent. The captured CO2 can then be further processed or sequestered underground or at sea.
Proven technology includes the SelexolTM Process, patented in the late sixties by the Allied Chemical Group, which used a solvent made of a mixture of dimethyl ethers of polyethylene glycol. The Dow Chemical Company acquired the gas processing expertise from Union Carbide in 2001 which is offered under license by several engineering companies. Clariant GmbH produces an equivalent solvent with their Genosorb product range.
CHEMCAD is being used to simulate this process involving the absorption, desorption and compression of CO2. A modified equation of state model has recently been developed to provide enhanced performance prediction of this process.
Key parts of this technology are Flue Gas Desulphuristaion(FGD) for the removal of SO2 by spray scrubbing with limestone, direct contact cooling (DCC) and then reactive absorption of CO2 using inhibited amine blends. The captured CO2 is then desorbed and compressed for transfer and sequestration in an appropriate reservoir.
Process models have been developed, using CHEMCAD, based on a study carried out by the International Energy Agency (IEA). Thermodynamic K values used were NRTL with Electrolyte for FGD, Ideal Vapour Pressure for DCC, Amine for CO2 Absorption and Desorption and Benedict Webb Ruben Starling (BWRS) Equation of State, with modified parameters, for Compression.