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  • 學位論文

二氧化碳化學吸收分流程序之程序最佳化與控制

Process Optimization and Control of Split-flow Chemical Absorption System for Carbon Dioxide Capture

指導教授 : 張煖

摘要


在可見之未來,化石燃料發電仍將是能源供應之最主要方式,其二氧化碳捕捉是面對溫室效應必須採行之作法。處理燃燒後二氧化碳的最可行技術為醇胺化學吸收程序,然而該程序耗能較高,除了研究高效節能之吸收溶劑外,也需藉由節能流程設計、最佳操作條件與有效控制系統,以使該技術能夠應用於二氧化碳之捕捉。 本研究針對一個300MW燃煤電廠煙道氣之二氧化碳化學吸收程序,利用程序模擬軟體Aspen Custom Model®(ACM)完成了二氧化碳乙醇胺化學吸收程序之動態速率模式建立。使用30wt% MEA並以90%吸收效率為目標,探討了簡單分流節能流程的設計與穩態最佳化分析,以最低單位二氧化碳捕捉再沸器熱負荷為目標函數,繼而提出利用穩態最佳解為設定點之最佳化控制策略,提出多種控制架構,與傳統控制架構進行控制性能之比較。 穩態最佳化分析,以最低單位捕獲能耗為目標得到簡單分流流程之能耗為3.5 GJ/ton CO2。各種控制架構的控制性能分析結果顯示LG-TStr為最佳之控制架構,相較於CC-TStr傳統控制,LG-TStr 達最終穩態所需時間較傳統控制減少約0.7小時,安定期之二氧化碳排放量可減少61%,安定期能耗可減少62%。

並列摘要


Fossil-fueled power generation will still be the major energy supply method, hence the carbon capture for power plant is essential for the control of global warming. Chemical absorption using amine solvents has been identified as the most feasible technology for post-combustion carbon capture. However, the high energy consumption is still a major problem and requires the development of high-efficient solvents, energy-saving flowsheets, optimal operation conditions and effective process control. In this study, for a 300 MW coal-fired power plant, a dynamic rate-based model for the overall amine-based absorption processes has been developed on the Aspen Custom Modeler® platform. The model was further utilized for steady state optimization of an energy-saving flowsheet, i.e. the simple-split flow configuration. Several control schemes based on the optimal solutions as the set-points of controllers were proposed and compared to the conventional control scheme for the control performance. For the energy-saving process, the steady state optimization study gives the minimal unit capture reboiler-duty of 3.5 GJ/ton CO2. The best control scheme is LG-TStr, compared to the conventional control scheme, CC-TStr, the stabilization period CO2 emission and reboiler-duty can be reduced by 61% and 62%, respectively.

參考文獻


Aspen Technology, Inc. Jump start: Aspen Custom Modeler V8. 2015.
Chang, H., Shih C.M, Simulation and optimization for power plant flue gas CO2 absorption-stripping systems, Separation Science and Technology, 40, 877-909, 2005.
Chen, S., Pan, Z., Gas pressurized separation column and process to generate a high pressure product gas, United States Patent, US 8,425,655 B2, 2013.
Chikukwa A., Enaasen N., Kvamsdal H.M., Hillestad M., Dynamic modeling of post-combustion CO2 capture using amines – A review. Energy Procedia 23, 82-91, 2012.
Cousins A., Wardhaugh L.T., Feron, P.H.M., A survey of process flow sheet modifications for energy efficient CO2 capture from flue gases using chemical absorption, International Journal of Greenhouse Gas Control, 5, 605-619, 2011a.

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