Experimental Study on CO₂/CH₄ Separation Respectively by Membrane, Chemical and the Combined Method

Separation efficiencies of CO₂/CH₄ by membrane separation and chemical absorption were studied respectively in a hollow fiber membrane contactor test rig and a packed tower test rig, and subsequently a new CO₂ removal technology was proposed. CO₂/CH₄ separation experiments were carried out in the new test rig combining the hollow fiber membrane with the packed tower, so as to analyze the influence of various factors on the CO₂ removal effect, and to compare the CO₂ removal efficiency among the three separation methods. Results show that the membrane separation has low CO₂ removal efficiency and low CH₄ recovery ratio, which suits to deal with the gas of small flow rate with undemanding separation efficiency; the chemical absorption has high separation efficiency and high CH₄ recovery ratio, which suits to process the gas with demanding separation efficiency; the combined method has low separation efficiency and high CH₄ recovery ratio, which suits to deal with the gas of high flow rate with undemanding separation efficiency.