| 摘要: | 本研究探討變溫吸附程序處理水煤氣反應(water gas shift reaction, WGS)以及變壓和變溫吸附程序(pressure and temperature swing adsorption, PSA and TSA)處理甲烷重組反應(steam methane reforming, SMR)，所使用的吸附劑分別為Na2O-promoted alumina和K2CO3-promoted hydrotalcite，吸附反應器依據Le Chatelier原理，可藉由吸附劑選擇性地移走產物來增加正向反應速率和轉化率，目的為產生燃料電池等級之氫氣(極高純度之氫氣及一氧化碳濃度<100ppm)，並將二氧化碳濃縮回收減少溫室氣體的排放。
模擬程式中使用了method of lines結合upwind differences和cubic spline approximation，再以ODEPACK套裝軟體中之LSODE程式對時間作積分，估計出下段時間的濃度、溫度及壓力，之後一直重複循環計算到系統達到週期性穩態為止。
本研究先以程式驗證Na2O-promoted alumina的突破曲線、WGS TSA 單塔六步驟程序、SMR TSA 單塔三步驟，證明程式的可信度。
本研究使用了三種不同的吸附反應程序，分別為WGS TSA 單塔六步驟程序、SMR PSA 單塔四步驟程序、SMR TSA 單塔三步驟程序。三個程序的最佳操作條件是經由不同的操作變因探討後得到的，例如：進料組成、進料壓力、進料時間、吸附劑和觸媒的比例等。
This study is numerically investigating Pressure Swing Sorption Enhanced Reaction Process and Thermal Swing Sorption Enhanced Reaction Process on steam-methane reforming (SMR) and water gas shift (WGS) reaction by Na2O-promoted alumina and K2CO3-promoted hydrotalcite, respectively. According to Le Chatelier’s law, the forward reaction rates and conversion can be increased by removing some products selected. Therefore, this concept can be used to generate product of fuel-cell grade hydrogen (very high-purity hydrogen with <100ppm CO). Carbon dioxide can also be recovered and sequestrated to reduce greenhouse gas effects.
The method of lines is utilized, combined with upwind differences, cubic spline approximation and LSODE of ODEPACK software to solve the problem. The concentration, temperature, and adsorption quantity in the bed are integrated with respect to time by LSODE of ODEPACK software. The simulation is stopped when the system reaches a cyclic steady state.
In this study, we first simulate breakthrough curve of Na2O-promoted alumina, WGS temperature swing adsorption (TSA) single-bed six-process and SMR TSA single-bed three-process cited from literatures to prove the accuracy of simulation program.
Three different processes have been studies, WGS TSA single-bed six-process, SMR pressure swing adsorption (PSA) single-bed four-process and SMR TSA single-bed three-process. The optimal operating conditions are obtained by varying operating variables, such as feed time, feed pressure, feed composition, ratio of adsorbent and catalyst, etc. |
