The principle of gas absorption is similar to that of solvent extraction process.Instead of solution feed, the waste gas stream (stream1) at a rate of 50kmol/min,contains 2500ppm So2, is fed to the absorber. Then,the solvent (stream2) with specific gravity of 1.30,at a rate of 1000L/min,is introduced to the absorber to dissolve SO2 out of the waste gas stream. The Effluent gas (stream3) is a treated gas, discharged to the atmosphere,while the Effluentliquid(stream4) is the solvent that absorbed SO2 for further processing. This process is operated at steady state.