氧化鈣改質以提昇其捕獲二氧化碳溫室氣體之循環再生能力研究

Abstract

二氧化碳捕獲及封存技術 (Carbon dioxide Capture and Storage, 簡稱CCS) 為聯合 國IPCC 組織評估為未來可行且具成本效益之溫室氣體減量方案之一，然而即使是目前 為止最為成熟的醇胺(amines)吸收技術也仍有成本與耗能均過高之缺點，因此各類處理 方法仍於世界各地持續研究開發中。據估計到2100 年時，全球將投入6,600~66,000 億 美元至CO2 減量技術中。因此我國如果在CCS 技術上能掌握技術先機，不僅可以有效 減緩我國之CO2 排放，且可以將技術輸出國外，創造出新商機。依文獻資料顯示，吸附 為CCS 技術中較可行之技術之一，而在所有之吸附材料中，CO2 吸附容量高、具選擇 性、吸附速率高、大量存在且便宜的材料，當屬氧化鈣(CaO)莫屬，但其卻有著容易劣 化，導致再生次數少之缺點。 本計畫擬以兩年時間，將氧化鈣分別以添加金屬改質、以及氧化鈣中孔洞(奈米)化 兩種改質方式，來減少其劣化速率，進而達到增加CO2 捕獲再生次數、降低CO2 吸附 成本之目的。於研究中將藉由TGA 熱重分析及管柱式反應器進行CO2 反應再生吸脫附 測試，來獲得反應時間、水氣、CO2 進流濃度等對改質後CaO 吸附CO2 之吸附容量、 吸附效率與再生性之影響。本計畫之預期創新性成果包括: (1). 其將為國際上首次以氣 膠快速製程製造中孔洞CO2 吸附材之研究 (2).將為國際上首次結合金屬改質與中孔洞 化改質，以避免CaO 劣化之研究。

The Carbon-dioxide Capture and Storage (CCS) has been reported by the IPCC as one of the cost-effective means for CO2 greenhouse gas mitigation. However, even the most matured and well-studied amine absorption process has encountered the drawbacks of high installation and operation costs as well as high energy consumption. Therefore various CO2 reduction technologies are being researched and developed worldwidely. It is estimated that by the year of 2100, the total expenditure on CO2 capture could be around $660~6,600 billions USD. Thus a new technological industry might be established if Taiwan can be in the leading position of CCS technologies. Literature data have shown that adsorption is one of the promising technologies for CO2 reduciton, of which the CaO chemical adsorption provides the advantages of high CO2 adsorption capacity, adsorption rate, and selectivity. In addition, the CaO is made from the abundunt limestone minerals thus its price is relatively cheaper. However the disadvantage of CaO adsorption is that it is easily deteriated after cyclic adsorption. The purpose of this study is to modify the CaO with metal additives, and a mesoporous CaO is also to be manufactuted by fast aerosol process of evaporation induced self assembly (EISA) process. It is expected that via modification of the CaO, either by metal additives or mesoporization, can prevent the CaO from fast deteriation during cyclic adsorption while still maintain its high selectivity and adsorption rate. The cyclic adsorption test will be performed by both TGA and column tests so that the reactor design parameters such as adsorption rate and adsorption capacity can be obtained, and the effects of humidity and CO2 inlet concentration can be studied. The novelty of this study relies on that it is the first attempt on using the EISA process for manufacturing high surface area of mesoporous CaO, and it is the first attempt that combines the metal addition and the mesoporization process on CaO modification.