在本論文中利用二階段真空變壓吸附(two-stage vacuum swing adsorption)製程來分離煙道氣中的SO2，CO2 和NO2。將進料組成設為18%CO2、0.5%SO2、0.13%NO2、其餘為N2 。第一階段SO2-VSA (vacuum swing adsorption) 程序吸附劑採用Doewx MWA-1處理二氧化硫與二氧化氮，吸附等溫線為loading ratio correlation等溫線；第二階段CO2-VSA程序吸附劑採用13X沸石處理二氧化碳，吸附等溫線為Langmuir等溫線。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。在操作過程中，將第一階段SO2-VSA所釋出的廢氣儲存在儲存槽中，而第二階段CO2-VSA是以儲存槽中的氣體為進料，進一步處理CO2 氣體。
二階段VSA係同時模擬，此程序可將為0.5﹪SO2濃縮至6.43%，回收率達92.13%；0.13﹪NO2濃縮至1.00%，回收率達54.99%；18﹪CO2濃縮至71.88%，回收率達84.31%；本研究並探討各操作參數(諸如：各個步驟操作時間、儲存槽體積與沖洗比，進料壓力和脫附壓力等)對程序效能的影響。

This study uses a two-stage vacuum swing adsorption process to separate SO2, NO2 and CO2 from flue gas. Simulation is performed for the bulk separation of SO2/NO2/CO2/N2 (0.5/0.13/18/81.37 vol %) system. The first stage of SO2-VSA (vacuum swing adsorption) utilizes Dowex MWA-1 as adsorbent to recover SO2 and NO2, and the second stage of CO2-VSA utilizes 13X zeolite as adsorbent to recover CO2. The equilibrium mixture adsorption in SO2-VSA and CO2-VSA can be expressed by the loading ratio correlation (LRC) and extended Langmuir isotherm, respectively. This study uses the equilibrium model and the pressure drop can be neglected. We assumed instantaneous equilibrium between the solid and gas phase with non-isothermal operation. In operating process, the waste stream of SO2-VSA is taken as the feed stream of CO2-VSA.
Two-stage vacuum swing adsorption process is simultaneously simulated. The 0.5%SO2 in the feed can be concentrated to 6.43% in the product with a recovery of 92.13%, the 0.13%NO2 in the feed can be concentrated to 1.00% in the product with a recovery of 54.99%, and the 18%CO2 in the feed can be concentrated to 71.88% in the product with a recovery of 84.31%. The effects of operating variables such as tank volume, P/F ratio, adsorption pressure, desorption pressure, and steps time are investigated on the performance of this study.

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