ENERGY REQUIREMENT OF A TWO-STAGE MEMBRANE SEPARATION UNIT OF CO2 FROM FLUE GASES OF THE POWER UNIT

In the paper a possibility of the improvement of the effectiveness of the work of membranes for CO2 capture was analyzed. The structure of a two-stage membrane system and its influence on the quality of the obtained carbon dioxide was presented. For the calculations Aspen software was used. The influence of the surface area of the membrane in the first and second membrane stage on the purity and recovery ratio of the separated CO2 was determined. The influence of these parameters on the power of the devices needed for separation, i.e. compressors and vacuum pumps and on the energy requirement of the process was also analyzed. The method for decreasing energy need of the process through the recovery of a part of the power needed for driving of the compressor by implementation of the expander was proposed. The proposed system allows for the separation of 90% of emitted CO2 from the energy unit with the purity higher than 90%. The influence of the CO2 separation installation on power and efficiency degradation of the energy unit was presented.