Separation and recovery of carbon dioxide by a membrane flash process utilizing waste thermal energy

AbstractThe membrane flash process utilizing waste thermal energy was developed to realize an energy-saving technology and to substitute it for a conventional regenerator. The operating conditions of a membrane flash at high temperature were studied. The DEA concentration and the flashing pressure had optimum values to improve the performance and reduce the energy consumption for CO2 recovery. The petroleum refinery process and iron manufacturing process were proposed for candidate processes that actually had waste energy sources. Energy consumption and costs for CO2 recovery in the membrane flash and chemical absorption were estimated by custom-made program and discussed under the same conditions. The membrane flash was suitable for the CO2 emission sources that had high CO2 concentration independently of the plant scale. The chemical absorption was suitable for large-scale sources, even if the CO2 concentration was low