動力工廠燃燒所產生的二氧化硫是造成酸雨現象的主因。如要回收二氧化硫，一般的處理方法乃利用溶劑回收，但是有二次污染的問題。但如果使用變壓吸附法回收煙道氣中的二氧化硫，則不會有此問題，所以近年來這方面的研究逐漸受到重視。 本研究是由模擬方式進行兩種真空變壓吸附程序的探討。進料為0.5﹪SO2，18﹪CO2，其餘為N2的混合氣體，吸附劑採用XAD-16（NO-treated）。模擬時採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，故忽略吸附塔內壓力降。 模擬程式採用線方法，加上可調的節點，將偏微分方程組轉換成常微分方程組。用差分法估計微分值，塔內各點的流速則使用三次多項式估算。最後用ODEPACK軟體中的LSODE對時間積分求得聯立方程式的解。 以此模擬程式探討不同參數對產物濃度與回收率的影響，期能藉此程序的探討，提供實驗程序上的考量。 The emission of SO2 from power plants that burn fossil flues is the major cause for acid-rain phenomena. So far，the removal of SO2 is mainly achieved by gas absorption，employing carbonates or alkano- lamines as the absorbent，which generates waste-solution pollution. Since PSA processes don’t generate secondary pollution problem，it can concentrate and recover SO2 from flue gas and has gained wide attention of researchers recently. Two vacuum swing adsorption（VSA）processes for SO2 recovery with XAD-16（NO-treared）as adsorbent are chosen in this study. The feed gas consists of 0.5﹪SO2 ，18﹪CO2 and the rest N2.Equilibrium model with no bed pressure drop，and instantaneous equilibrium between the solid and gas phases are assumed in simulation. Noisothermal operation is considered. Method of lines with adaptive grid points is utilized in simulation. The estimation of the spatial derivatives uses upwind difference to reduce the PDEs into ODEs, and it uses cubic spline approximation to estimate flow rate in the adsorptive bed. Finally, the integration with respect to time utilizes program LSODE of ODEPACK. The influence of operation parameters has been studied for the concentration and recovery of product by the simulation program. It is expected to help creating future experimental system by using the two processes.
