為了解決能源危機的問題，全球正努力尋求新的能源方案，氫能被視為優良的能源載體(energy carrier)，其生產來源非常廣泛。於本研究中，分別透過乙醇蒸汽重組(ethanol steam reforming)及水氣轉移反應(water gas shift reaction)生產氫氣，並透過鈀膜管(Palladium membrane tube)進行氫氣分離。本研究以數值模擬進行，透過數值模擬，可以減少研究實驗之時間及材料成本並能夠分析、改良實驗設計。本文主要分兩大部分，如下所述。
在本研究的第一部分為以計算流體力學(Computational Fluid Dynamics, CFD)方法進行模擬，針對乙醇蒸汽重組於鈀膜管反應器之產氫研究，透過對雷諾數(Reynolds number, Re)、蒸汽乙醇比(steam to ethanol molar ratio, S/E ratio)以及溫度進行參數設定。當進料溫度於600 °C時，一氧化碳的濃度會於雷諾數為50時來到低點，這是因為其溫度會因為在雷諾數逐漸增高至50時，反應器溫度會逐漸下降，使得乙醇蒸汽重組中的水氣轉移反應傾於消耗一氧化碳；當雷諾數逐漸增高超過100後，會因乙醇轉化率下降，造成一氧化碳濃度增加。而在500 °C且雷諾數為10的條件下，乙醇轉化率可以到達100%，且氫氣回收率可以達到57.46%。透過分析結果顯示，雷諾數對於氫氣回收率的影響甚大，可以理解為乙醇蒸汽重組中的水氣轉移反應和氫氣滲透鈀膜管，兩者皆需要足夠的時間進行，且因雷諾數值越大，同時代表進入反應器的氣體越多，造成反應器溫度迅速下降，間接降低鈀膜管的氫氣回收能力。對於蒸汽乙醇比和進氣溫度的結果中，高蒸汽乙醇比和高溫可以使反應產生更多的氫氣，然而過量的氫氣會使鈀膜的氫氣回收比率下降，並因反應造成的高溫及進氣高溫使鈀膜管面臨熔化之風險。
本研究於第一部分中發現水氣轉移反應是非常重要的關鍵反應，因此，第二部分以水氣轉移反應為主，並以交叉流反應器進行模擬。為了解交叉流反應器之性能，研究了雷諾數、鈀膜管數量(串列)對交叉流反應器的影響，同時也針對觸媒床厚度進行分析，並比較了串列配置與過去文獻中之最佳化配置性能。透過模擬結果發現雷諾數依然對於反應器有者重大的影響，對於交叉流反應器而言，較高的雷諾數同時造成一氧化碳轉化及氫氣回收較為困難；對於觸媒床厚度而言，觸媒床厚度會影響膜管間的速度與溫度，並間接影響了一氧化碳轉化率與氫氣回收率，越厚的觸媒床會使最佳化配置有較好的一氧化碳轉化率，相較於串列配置能有3%的性能提升，這主要是因為優化配置能適當的避開前方膜管產生的低速區及濃度極化現象，於最佳化配置中，最大的一氧化碳轉化率能提高3%，其氫氣回收率為34.27%。

In order to solve the energy crisis, the world is striving to find new energy solutions. Hydrogen is regarded as an excellent energy carrier and its production sources vary widely. In this study, hydrogen was produced by ethanol steam reforming (ESR) and water gas shift reaction (WGSR), respectively. Hydrogen separation was through a palladium (Pd) membrane tube. Numerical simulation was used in this study. Through numerical simulation, the time and material cost of the experiment can be reduced and the experimental design can be analyzed and improved. This study was divided into two major parts.
In the first part of the study, the Computational Fluid Dynamics (CFD) method was used to simulate the hydrogen production through ethanol steam reforming in the Pd membrane reactor. The parameters studied in this investigation include; Reynolds number (Re), steam to ethanol molar ratio (S/E ratio), and inlet temperature. At an inlet temperature of 600 °C and a Re = 50, the CO concentration was the lowest. This is because the temperature gradually decrease as the Reynolds number increases to 50. And low temperatures are suitable for WGSR in the ESR which consumes the CO. When the Reynolds number is increased by more than 100, the CO concentration is increased due to a decrease in the ethanol conversion. It can be observed that the ethanol conversion can go up to 100% at 500 °C and the Re = 10, and the hydrogen recovery (HR) can reach up to 57.46%. The results show that the Reynolds number has a great influence on the HR, and it can be considered that the WGSR in ESR and the hydrogen permeation of the palladium membrane require sufficient time. The large Reynolds number represents a higher gas flow rate into the reactor, which causes a drastic decrease in the temperature. Further, it lowers the performance of the Pd membrane. In this study, high S/E ratio and high temperature at the inlet can increase hydrogen production through the reaction, however, excess hydrogen will reduce the HR ratio of the palladium membrane. Therefore, the palladium membrane may be under a potential risk of melting due to the high temperature inside the reactor. This high temperature could be caused by reaction heat and inlet temperature.
It is found that WGSR is a very important reaction in the first part of the study. Therefore, the second part focused on WGSR and the simulation was carried out in a cross flow reactor. The influences of Reynolds numbers and the number of palladium membrane tubes (tandem), and thickness of the catalyst layer were studied. The tandem configuration was compared to an optimized proposed in a previous study. The results show that the Reynolds number highly influenced CO conversion and HR for a cross flow reactor. Large Reynolds number decreases the CO conversion and HR and vice versa. The thickness of the catalyst bed will affect the speed and temperature between the membrane tubes, and indirectly affect the HR and CO conversion. A thicker the catalyst bed will improve the optimized configuration to have better performance. The optimized configuration has a CO conversion improvement of 3% compared with the tandem configuration. This is because the optimized configuration can avoid the low speed zone and concentration polarization from the front membrane tube. In optimized configuration. the highest CO conversion raise up to 3%, and the HR is 34.27%.

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