Energy Consumption Analysis of Cryogenic-membrane Hybrid Process for CO2 Capture from CO2-EOR Extraction Gas

CO2-EOR (CO2-enhanced oil recovery) is an effective method to increase oil recovery. With more and more exploitation of oilfields, a large amount of CO2 will spill out the surface, which can cause serious environmental problems. At present, high energy consumption, low CO2 purity and recovery are still the main challenges of single CO2 capture technology. Therefore, the combination of different CO2 capture technology is a reasonable choice to overcome these bottlenecks. In this work, a cryogenic-membrane hybrid process for the CO2 capture from extraction gas was proposed. In detail, the main parameters of cryogenic-membrane hybrid process (i.e., CO2 content in feed gas, compression pressure, membrane area, liquefaction temperature) which effect on CO2 properties were investigated. The simulation results indicated that the CO2 purity and recovery rate of cryogenic-membrane hybrid process can achieve 99% and 96%, respectively, and the energy consumption of the whole system was less than 850 MJ t(-1) CO2. Compared with membrane and cryogenic process, cryogenic-membrane hybrid process can save about 10% energy consumption. The results of this work indicate that cryogenic-membrane hybrid process has great potential for practical application.