A 2-stage PSA process for the recovery of CO_2 from flue gas and its power consumption

摘要

A PSA process for the recovering of CO_2 from flue gas is usually composed by 2-stage adsorption unit. At the first stage of the 2-stage PSA, CO_2 is enriched to 40-60%, and then further concentrated to 99%, at the second stage. Performance of the 2-stage PSA process for CO_2 recovery from flue gas is investigated experimentally and theoretically. Power consumption of a pilot scale process was experimentally measured and it ranged from 1.26 kWh/Nm~3-CO_2 to 1.52 kWh/Nm~3-CO_2 depending on the type of vacuum pump used. By a simulation study on the power consumption, it was shown that substantial reduction of power consumption could be obtained with a more simple process scheme. With the 2-stage PSA process composed of 2-bed for each stage, 99% CO_2 is obtained with 80% recovery from the feed containing 10.5% CO_2. Theoretical power consumption of the above process was estimated as 0.28 kWh/Nm~3-CO_2.