觸媒反應器之計算流體力學模擬

CFD simulation for catalytic reactors

陳逸明(Yi-Ming Chen)

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(2007年)

https://doi.org/10.6846/TKU.2007.00545

摘要

本論文使用計算流體力學(Computational Fluid Dynamics，CFD) 軟體FLUENT配合一系列之使用者自定函數(User Defined Function, UDF)完成了自二氧化碳合成甲醇之填充床式觸媒反應器(Packed Bed Catalytic Reactor，PBR)與觸媒薄膜反應器(Catalytic Membrane Reactor，CMR)之三維模式模擬，模式納入了填充床球型觸媒顆粒反應器中(1)巨相之流力、熱傳與質傳；(2)觸媒顆粒內之流力、熱傳、質傳與化學反應；(3)巨相與觸媒顆粒間之流力、熱傳與質傳；及(4)薄膜兩側巨相間之流力、熱傳與質傳。流體速度限制於層流範圍。
透過模擬探討了反應器內部之特性分佈，包括壓力、速度、溫度與組成，並探討了參數之影響，包括觸媒顆粒孔徑、粒徑、操作壓力、進料流量、是否具薄膜與膜厚等。針對填充床之摩擦因子以及觸媒顆粒與巨氣相間之熱傳係數與質傳係數，本研究並比較模擬結果與文獻關聯式，結果顯示摩擦因子較吻合，熱傳係數與質傳係數則有極大差異。

關鍵字

薄膜反應器 ； 甲醇合成 ； 計算流體力學模擬 ； 填充床反應器

並列摘要

This thesis uses Computational Fluid Dynamics, combining with a set of User Defined Functions (UDF) to accomplish the simulation studies for the Packed Bed Catalytic Reactor (PBR) and the Catalytic Membrane Reactor (CMR) for methanol synthesis from carbon dioxide and hydrogen.

The model encompasses all important mechanisms for PBR and CMR, including (1) the hydraulic, heat and mass transfers of bulk gas; (2) the hydraulic, heat and mass transfers and chemical reaction of catalyst; (3) the hydraulic, heat and mass transfers between bulk gas and catalyst; (4) the hydraulic, heat and mass transfers between bulk gases and membrane. The fluid is in the laminar flow region.

The simulation facilitates the discussions on the profiles inside the reactor, including pressure, velocity, temperature and composition. The effects of catalyst particle pore size, diameter, operation pressure, feed flowrate, with or without membrane and membrane thickness are studied. The friction factor of the bed and the heat and mass transfer coefficients between catalyst particle and bulk gas are compared with the correlations reported in the literature. The friction factors are close to the correlations predictions, however, the heat and mass transfer coefficients are not and the data are very scattering.

並列關鍵字

Computational Fluid Dynamics ； Packed Bed Reactor ； Catalytic Reactor ； Catalytic Membrane Reactor ； Methanol Synthesis

參考文獻

Anthony, G. D. and N. Michiel, “CFD as a design tool for Fixed-Bed Reactors,” Ind. Eng. Chem. Res., Vol. 40, pp. 5246-5254, 2001.

Baiker A., M. New and W. Richarz, “Determination of intraparticle diffusion coefficients in catalyst pellets – a comparative study of measuring methods,” Chem. Eng. Sci., Vol. 37, No. 4, pp. 643-656, 1982.

Barbieri, G., G. Marigliano, G. Golemme and E. Drioli, “Simulation of CO2 hydrogenation with CH3OH removal in a zeolite membrane reactor,” The Chemical Engineering Journal 85 pp. 53-59, 2002.

Basile, A., L. Paturzo and F. Laganà, “The partial oxidation of methane to syngas in a palladium membrane reactor: simulation and experimental studies,” Catalysis today Vol. 67, pp.65-75, 2001.

Cogan, R., G. Pipko and A. Nir, “Simultaneous intraparticle forced convection, diffusion and reaction in a porous catalyst-III, depolymerization of paraldehyde,” Chem. Eng. Sci., Vol. 37, No. 2, pp. 147-151, 1982.