有鑑於日益加劇的溫室效應與全球暖化的現象,如何針對大型之二氧化碳排放源進行有效的二氧化碳捕捉成為當務之急。利用胺類吸收劑進行燃燒後二氧化碳捕捉已被視為具有高度捕捉效能與發展潛力的二氧化碳捕捉技術。在此技術中 ,一個理想的吸收劑應當同時具備高的二氧化碳吸收與脫附效能,以及低再生能耗。本研究中,設計了一套簡易的二氧化碳吸收與脫附實驗以探究並比較五種不同吸收劑之二氧化碳捕捉效能與再生能耗,此五種吸收劑分別為乙醇胺(Monoethanolamine, MEA)水溶液、高濃度對二氮己環(Piperazine, PZ)/二亞乙基三胺(Diethylenetriamine, DETA)/水溶液、高濃度對二氮己環/二亞乙基三胺/二甘醇(Diethylene glycol, DEG)/水之混合溶液、高濃度對二氮己環/二亞乙基三胺/甲醇(Methanol, MeOH)/水之混合溶液,以及高濃度對二氮己環/二亞乙基三胺/甲醇溶液。其中,高濃度對二氮己環/二亞乙基三胺/甲醇/水之混合溶液同時具備高二氧化碳吸收效能、高二氧化碳脫附效能,與低再生能耗之特性。此外,此一吸收劑即使於低溫條件(10-30oC)下亦無對二氮己環之結晶產生,且在整個二氧化碳吸收與脫附過程中並無非水溶性沉澱物產生於富二氧化碳溶液中,故無固體沉澱物堵塞於二氧化碳捕捉程序或衍生固體廢棄物處理之問題。因此,此一新型之高濃度對二氮己環/二亞乙基三胺/甲醇/水混合溶液可被視為極具發展潛力的二氧化碳吸收劑。
Post-combustion carbon dioxide (CO2) capture using amine-based absorbents has been considered as the most promising technology to effectively capture CO2 from coal-fired power plants. In this technology, an ideal absorbent should have both high absorption/desorption efficiency and low regeneration energy penalty. In this study, a set of simplified experiments was devised to evaluate the overall capture performances of five absorbents, including 30wt% monoethanolamine (MEA) solution, piperazine/diethylenetriamine/water (PZ/DETA/H2O) solution, piperazine/diethylenetriamine/diethylene glycol/water (PZ/DETA/DEG/H2O) blend, piperazine/diethylenetriamine/methanol/water (PZ/DETA/MeOH/H2O) blend, and piperazine/diethylenetriamine/methanol (PZ/DETA/MeOH) solution. Among the five absorbents, the novel PZ/DETA/MeOH/H2O blend achieved high absorption efficiency, high desorption efficiency, and low regeneration energy penalty. In addition, this blend did not suffer the problems of PZ crystal formation in absorbents at low temperature (10-30oC) and precipitation in CO2-rich solution. Therefore, this novel PZ/DETA/MeOH/H2O blend can be considered as a potential candidate for CO2 capture reagent.