Process Design of CO2 Desorption from physical solvent Di-Methyl-Ethre of poly-Ethylene-Glycol

Integrated Gasification Combined Cycle (IGCC) is a promising technology for effective control of green-house gas emission through CO2 capture pre-combustion process. This article describes the relative advantage of a novel energy efficient process configuration for desorption and compression of CO2 (previously absorbed by physical solvent Di-Methyl-Ethre of poly-Ethylene-Glycol (DMEPEG)). DMEPEG is a blend of several polymeric chain length (n = 3 to 9) of CH3-O-[C2H4O]n-CH3 which is a polar organic liquid solvent.
Desorption of dissolved CO2 from solvent at highest possible pressure is helpful to minimize the power consumption for subsequent compression of CO2. This article quantifies the effect of heating the DMEPEG solvent to 120 °C for CO2 desorption (compared to CO2 desorption at 35 °C) on the regeneration (desorption) of CO2 at various pressure stages.
CO2 desorption performance of DMEPEG solvent is assessed using ProTreat® simulation software. Depressurization of 4.455 kmol/s DMEPEG solvent (with dissolved gas) beginning at 120 °C results in desorption of 2.077 kmol/s CO2 capture (91.4 kg/s) out of initially dissolved 2.194 kmol/s CO2 (94.66 %). Solvent heating upto 120 °C (instead of 35 °C) can compress the 97.1 kg/s CO2 from 3 barA to 34.7 barA consuming 6 MW (instead of 8.15 MW) power for CO2 compression, thus resulting in 15 % saving for CO2 compression upto 120 barA consuming 14.1 MW power consumption.