Preliminary estimations of energy and cost for CO2 recovery by a membrane flash process utilizing waste thermal energy

The membrane flash process utilizing waste thermal energy was developed to achieve an energy-saving technology and to substitute it for a conventional regenerator. The operating conditions of the membrane flash at high temperature were studied. The petroleum refining process and iron manufacturing process were proposed for candidate processes that actually had waste energy sources. The DEA concentration and the flashing pressure had optimum values to improve the performance and reduce the energy consumption for CO2 recovery. Energy consumptions and costs for CO2 recovery in the membrane flash and chemical absorption were estimated by a process simulator and discussed under the same conditions. The membrane flash can achieve lower energy capture than the chemical absorption for the above industrial processes. The membrane flash is suitable for the CO2 emission sources that had high CO2 concentration independently of the plant scale. The chemical absorption can be applied if the plant scale is large and also the CO2 concentration is low.