二氧化碳吸收與氣提薄膜接觸器之計算流體力學模擬

CFD simulation of membrane contactors for carbon dioxide absorption and stripping

甘皓宇(Hau-Yu Gan)

指導教授 ： 張煖

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2016年)

https://doi.org/10.6846/TKU.2016.00299

摘要

本研究提出創新的二氧化碳併合薄膜吸收與氣提薄膜接觸器，並利用計算流體力學(Computational Fluid Dynamics, CFD)模擬探討其流力與質傳特性。本研究使用FLUENT軟體之層流模式與VOF (Volume of Fluid)多相模式，薄膜為可滲透邊界條件，模擬四種併合模組，包括使用空通道與具間隔物通道，以及平行流與交錯流配置之組合。模式之驗證是利用文獻實驗數據且獲得相當接近之結果。
具間隔物模組之流力與質傳特性皆受到間隔物配置影響，呈現上下震盪變化，其壓降與質傳係數均高於空通道。具間隔物通道可提升二氧化碳於液體通道中之擴散，交錯流配置則可有效使被吸收之二氧化碳於同側下游薄膜處被氣提。關於質傳係數與文獻關聯式之比較，除平行流空通道模組氣體通道外，各模組質傳係數均較各關聯式預測值高，間隔物通道較空通道之質傳係數與強化因子較文獻關聯式高。

關鍵字

計算流體力學 ； 併合模組 ； 薄膜吸收 ； 薄膜氣提 ； 間隔物 ； 交錯流

並列摘要

In this study, novel hybrid absorption/stripping membrane contactors (HASMC) for carbon dioxide capture using physical solvent are proposed and investigated by the computational fluid dynamics (CFD) simulation. The laminar flow model and the Volume of Fluid (VOF) multiphase model in FLUENT were employed with the membranes defined as permeable boundary conditions. Four HASMCs were studied, including the combinations of empty channel and spacer-filled channel with parallel flow and cross-flow.
The fluid flow and mass transfer characteristics of spacer-filled channels show fluctuating patterns corresponding to spacer configurations. The pressure drop and mass transfer coefficients of spacer-filled channels are all higher than the empty channels. Spacer-filled channels can enhance the carbon dioxide diffusion in the liquid channel. Cross-flow configuration allows effective stripping of the absorbed carbon dioxide with the downstream membrane allocated at the same side of the liquid. Except the gas channel of the empty-channel parallel-flow modules, the mass transfer coefficients are much higher than the conventional correlations.

並列關鍵字

Computational fluid dynamics ； Hybrid modules ； Membrane absorption ； Membrane stripping ； Spacers ； Cross-flow

參考文獻

Amrei, S.M.H.H., S. Memardoost, A.M. Dehkordi, Comprehensive modeling and CFD simulation of absorption of CO2 and H2S by MEA solution in hollow fiber membrane reactors, Published online November 18, 2013 in Wiley Online Library (wileyonlinelibrary.com).

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Chang, H., J.-A. Hsu, C.-L. Chang, C.-D. Ho, CFD simulation of direct contact membrane distillation modules with rough surface channels, Energy Procedia, 75, 3083-3090, 2015b.

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