| 摘要: | 隨著因人類活動而不斷增加大氣中的二氧化碳、甲烷等溫室氣體，被認為是造成全球暖化及氣候變遷的主要原因，因此，如何將排放之溫室氣體重新捕獲的技術是目前工業界所關注的。碳捕獲、再利用與封存技術 ( Carbon Capture, Utilization and Storage, CCUS ) 內捕獲二氧化碳的方式技術有許多種，其一方法可利用變壓吸附製程，依據不同吸附劑的性質，並搭配不同的操作步驟達成分離氣體之目的，其優點為操作簡單、低能耗、低操作成本等。
本研究利用兩階段真空變壓吸附程序，在塔內填充COSMO 13X分子篩，通入燃煤發電廠排放經前處理過後的煙道氣，此時煙道氣中二氧化碳占比約10 % - 12.5 %。本研究欲達成回收二氧化碳純度80%、回收率70 % 之目標，為了獲得能讓二氧化碳純度以及回收率達到實驗目標，選擇三個對於二氧化碳純度及回收率具有影響的因子，分別為第一階段雙塔程序之步驟1/4時間、步驟3/6時間、同向減壓壓力進行實驗設計( Design of Experiments , DOE )，當儲存足夠的第一階段雙塔程序塔底產品後，接著以第二階段之單塔三步驟的真空變壓吸附程序，提高第一階段之二氧化碳濃度，使整體二氧化碳純度達研究目標，並以實驗結果探討各因子對二氧化碳純度、二氧化碳回收率及能耗的影響，接著分別建立二氧化碳純度、二氧化碳回收率，以及第一階段能耗的迴歸模型，最後以二氧化碳純度、二氧化碳回收率，以及第一階段能耗分析兩種最適化的結果，並推估此結果下的各因子設定值，以求二氧化碳純度以及回收率達到研究目標。
;With the continuous increase of carbon dioxide (CO2), methane (CH4), and other greenhouse gases in the atmosphere due to human activities, it is considered to be the main cause of global warming and climate change. Therefore, how to capture the greenhouse gases from emission is the current technology concerns of industries. There are many ways to capture carbon dioxide in Carbon Capture, Utilization and Storage (CCUS) technology. One of the methods is the pressure swing adsorption process (PSA), according to the properties of different adsorbents, and with different operation steps to achieve the purpose of gas separation. The advantages of PSA are simple operation, low energy consumption, and low operating cost.
In this study, a two-stage vacuum pressure swing adsorption (VPSA) process was used. The adsorption bed was filled with COSMO 13X molecular sieve. The discharge pre-treated flue gas of a coal-fired power plant was sent to the VPSA to capture CO2. At this time, carbon dioxide in the flue gas accounted for about 10% to 12.5%. The research aimed to achieve the goal of carbon dioxide purity of 80% and recovery reaching 70%. In order to achieve the goal of carbon dioxide purity and recovery, we chose three factors that have imported impacts on the purity and recovery of carbon dioxide, which are step 1/4 time, step 3/6 time, and cocurrent depressurization pressure of the first-stage dual-bed PSA. After that the CO2 product of the first-stage PSA filled the storage tanks, the second-stage single-bed three-step VPSA process was used to increase the carbon dioxide concentration. The influence of each factor on carbon dioxide purity, carbon dioxide recovery, and energy consumption was discussed with design of experiments (DOE), and the regression models of carbon dioxide purity, carbon dioxide recovery, and energy consumption of the first stage were established respectively. Finally, optimal results were analyzed. At the optimal conditions, carbon dioxide purity and recovery from regression could reach the research goal. |
