燃煤電廠燃燒後薄膜分離碳捕捉程序中薄膜選擇性之影響

為數眾多之燃煤發電廠進行燃燒後碳捕捉程序是目前減少二氧化碳排放之重要方式之一。目前最成熟之碳捕捉技術為胺吸收法，然而其碳捕捉程序相當耗能且成本昂貴。在過去數十年中薄膜氣體分離碳捕捉程序，展現出其具有低能耗同時低碳捕捉價格之潛力。本實驗室曾針對燃煤電廠燃燒後之排放廢氣，採用薄膜方離方式，進行概念性設計。其中，並對於主要的程序設計參數如：壓力比、膜級切(Stage-cut)、流動型態、多級薄膜與回流等，依序探討並提出最佳化製程設計架構。其中並提出幾項特殊的燃燒後薄膜碳捕捉設計，包括預除水(water pre-removal)、空氣掃流(air sweep)等，不過其中不同製程區均採用相同的薄膜參數，並未因應不同製程單元需求的差異，進行更細緻化的分析。本研究基於Chang (2016)之最終設計架構，探討薄膜選擇性對燃燒後薄膜碳捕捉程序之影響，以及找出在各個模組使用不同選擇性薄膜時之最適化設計。在研究的過程中發現薄膜選擇性對於不同用途之薄膜模組的影響大相逕庭。其中對於主要的捕捉單元(薄膜1)而言，應該使用中高選擇性薄膜，而提濃單元(薄膜2)與掃流單元(AS薄膜)則應該可以使用低選擇性薄膜，以降低成本。目前燃燒後薄膜碳捕捉最佳的程序結果所需總薄膜面積為1.53million m2 且能耗為89MW，選擇性方面，薄膜1建議為100，薄膜2與AS薄膜建議為20，最終碳捕捉率可達90%而液態CO2產品濃度可以達到96.2%，二氧化碳捕捉價格估計約為$21/ton CO2，且能耗約莫佔了電廠550MW電力輸出中之16%。

關鍵字

薄膜；薄膜分離程序；碳捕捉；燃煤火力發電廠；煙道氣；氣體分離

並列摘要

One promising way to reduce CO2 emissions is post-combustion CO2 capture from flue gas at coal-fired power plant. A wide variety of capture techniques has been proposed and studied. Conventional Amine-based process is the dominate method used for CO2 separation. However, the process is energy-intensive and therefore it becomes very costly. Gas separation membrane process gives an opportunity to be a low cost and low energy consumption option for capturing CO2 from power plant flue gas. Membrane design considerations such as pressure ratio, stage cut, flow module, multi-stage configuration and recirculation have been studied. But membrane selectivity is also the important design consideration in the membrane separation process for CO2 capture. In this study, based on Chang’s optimum design (2016), we try to know how the selectivity effects the membrane process, and then help to determine the optimal design. We find out that the effects of membrane selectivity in each membrane modules is very different. For instant, modest and higher selectivity is suitable for the 1st stage membrane, but for the 2nd stage and air sweep membrane modules, we suggest using lower selectivity membrane. The optimized case has demonstrated that the required power consumption is 89 MW and the membrane area needed is 1.53 million m2. The 1st membrane selectivity is 100, 2nd membrane and airs weep membrane selectivity are20. The 90% CO2 capture is achieved and the final liquefied CO2 product purity can be reached to 96.2%. The CO2 capture cost is about $21/ton and the power consumption of the process (89MW) only occupy 16% of power plant output。

並列關鍵字

Membrane ； Membrane separation process ； CO2 capture ； Coal-fired power plant ； Flue gas ； Gas separation

參考文獻

[2] F. Birol, CO2 Emissions from Fuel Combustion Helights, in, OECD/IEA, 2015.

[3] J.D. Figueroa, T. Fout, S. Plasynski, H. McIlvried, R.D. Srivastava, Advances in CO2 capture technology—The U.S. Department of Energy's Carbon Sequestration Program, International Journal of Greenhouse Gas Control, 2 (2008) 9-20.

[5] T.C. Merkel, H.Q. Lin, X.T. Wei, R. Baker, Power plant post-combustion carbon dioxide capture: An opportunity for membranes, J. Membr. Sci., 359 (2010) 126-139.

[6] D.Y.C. Leung, G. Caramanna, M.M. Maroto-Valer, An overview of current status of carbon dioxide capture and storage technologies, Renew. Sust. Energ. Rev., 39 (2014) 426-443.

[7] B.Y. Li, Y.H. Duan, D. Luebke, B. Morreale, Advances in CO2 capture technology: A patent review, Appl. Energy, 102 (2013) 1439-1447.

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燃煤電廠燃燒後薄膜分離碳捕捉程序中薄膜選擇性之影響

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