透過膜接觸器新製程改善二氧化碳捕捉之能源效率

Improving energy efficiency through a novel carbon dioxide capture process of membrane contactors

何忠儒(Zhong-Ru He)

指導教授 ： 陳榮輝

中原大學/工學院/化學工程研究所/碩士(2013年)

https://doi.org/10.6840/cycu201301106

摘要

隨者各國的發展且大量的使用石油、煤炭與天然氣等石化燃料，導致CO2排放量遽增，提高溫室效應危害程度，因此探討如何減少CO2排放或有效的回收CO2並再利用為目前重要的課題。由於傳統的CO2捕捉系統為吸收塔與氣提塔的組合，且過去研究較著重於探討此系統操作設定上的調整使得能耗降低，但由於此系統最大能耗來自於再沸器，使得改善效果不明顯。由於薄膜接觸器亦可用在分離上，僅靠兩端流體的濃度差即可達到良好的分離效果，且設備的能耗極低。因此，本篇研究著重於以薄膜接觸器改善傳統製程上的缺陷，取代再沸器能耗過高的問題，進而有效的降低能源消耗。本篇研究先探討薄膜接觸器的物理模型，並分析在吸收與解吸時分離的效能，最後探討薄膜接觸器取代傳統再沸器後的節能效果。由研究結果顯示，傳統捕捉CO2系統單位成本為3.66 NTD/kg，而吸收與解吸皆以膜接觸器取代後，回收單位成本為35.73 NTD/kg，且此結構下需較多的膜接觸器，提高初始設備成本，而傳統吸收塔結合膜接觸器解吸捕捉CO2系統單位成本為1.32 NTD/kg。

關鍵字

能源改善 ； 膜接觸器 ； 二氧化碳

並列摘要

The rapid development and extensive use of fossil fuels, like oil, coal and natural gases, result in dramatic increase in CO2 emissions and rising level of harmful greenhouse effect. Being aware of this problem, many researchers devoted themselves to the reduction of CO2 emissions or effective recycling. The traditional CO2 capture system is a combination of an absorber and a stripper. Past research focused on the reduction of energy consumption by adjusting the system operation. However, the major energy consumption is the reboiler in the stripper. This makes the improvement of the traditional operation system not so significant. The membrane contactor is able to achieve good separation with concentration gradient between two side fluids and it has low power consumption. This study aims to improve the traditional method by using the membrane contactor as a replacement for the CO2 capture system. The physical model of the membrane contactor is first investigated with analysis on the absorption and desorption performance. Furthermore, the cost saving resulting from the use of the membrane contactor is also discussed. In the study, the operation cost of the traditional capture system with the absorber and the stripper is NT$3.66/kg while the operation cost of the membrane contactor based absorption and stripper system is NT$35.73/kg . However, the latter structure requires more membrane contactors. The corresponding equipment costs would increase. Alternatively, with the combination of the conventional absorber and the membrane contactor based stripper, the operation cost is $1.32/kg . Although it is slightly higher than the cost of the membrane contactor based absorption and stripper system, the equipment cost of the former is significantly less. As a result, compared to the traditional capture system, the proposed hybrid structure with the conventional absorber and the membrane contactor based stripper effectively reduces energy consumption.

並列關鍵字

carbon dioxide ； membrane contactors ； improving energy

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