火力發電廠所排放出含有硫、氮、碳多成分氣體混合物是造成酸雨與溫室效應的主要原因。使用變壓吸附法濃縮及回收煙道氣中二氧化硫、二氧化氮與二氧化碳，使之再利用，為解決問題方法之一。近年來這方面的研究已成為處理火力發電廠廢氣之首要。
本研究主要利用模擬方式，採用雙塔四步驟與三塔六步驟兩階段真空變壓吸附程序，處理進料為0.5﹪SO2、0.13% NO2與18﹪CO2，其餘為N2之煙道氣，吸附劑分別採用Dowex MWA-1(weak-base resin)與13X zeolite。模擬時所用的氣體分離機構為平衡模式，假設吸附塔內的同一截面積上固、氣兩相瞬間達成平衡，且為非恆溫之變壓吸附模式，因吸附劑顆粒大，故可忽略吸附塔內壓力降。
此程序可將濃度為0.5﹪SO2濃縮至6.04%，回收率達83%；18﹪CO2濃縮至75%，回收率達62%；探討各製程操作變數(諸如：沖洗比、進料壓力與各個步驟操作時間等等)對程序效能的影響。

The major cause for acid-rain and greenhouse-effect phenomena is the emission which carries gas mixture containing components sulfur，nitrogen and carbon from power plants that burn fossil fuel. The concentration and recovery of SO2，NO2 and CO2 from flue gas is important in solving such pollution problem. Vacuum swing adsorption (VSA) is a feasible technology for such purpose.
This study employes a two-stage VSA to concentrate and recover SO2，NO2 and CO2 from flue gas. The first SO2-VSA is a dual-bed four-step process using Dowex MWA-1 resin as adsorbent, and the second CO2-VSA is a three-bed six-step process using 13X zeolite as adsorbent. Non-isothermal simulation is performed for separation of SO2/NO2/CO2/N2 (0.5/0.13/18/81.37 vol %) system. This study uses the equilibrium model and the pressure drop can be neglected.
The SO2/CO2 (0.5/18 vol %) in the feed could be concentrated to (6.04/75 vol %) in product stream, having a recovery of (83/62 vol %) in this study. The effects of operating variables such as P/F ratio, adsorption pressure, steps time were investigated on the performance of this study.

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