Numerical Analysis on the Ethanol Steam Reforming in a Tubular Fixed-Bed Reactor

在管狀固定床反應器的乙醇蒸汽重組數值分析

黃竹愉(Chu-Yu Huang) ； 許文震(Wen-Jenn Sheu) ； 陳炎洲(Yen-Cho Chen)

《中國機械工程學刊》 43卷1期 (2022/02) Pp. 47-56

摘要

The ethanol steam reforming for hydrogen production in a tubular fixed-bed reactor is investigated numerically. The effects from the wall temperature (T_w), the gas hourly space velocity (GHSV), and the inlet molar ratio of steam to ethanol (ψ) are analyzed. For GHSV = 2000 h^(-1), the results show that for a higher T_w of 873 K and ψ=10, the methane molar concentration in the vicinity of inlet region is greater than that at outlet where an equilibrium state approaches. However, this phenomenon disappears for T_w = 673 K. The results reveal that a high ratio (78.2%) of produced hydrogen for ψ= 3 comes from the steam at T_w = 673 K, and the ratio of H_2 coming from the steam is remarkably decreased with increasing T_w, and more than 50% of hydrogen comes from steam for T_w ＜ 852 K. But forψ= 10, the ratio of H_2 coming from the steam is always slightly lower than that of H_2 coming from the ethanol. Based on the parameters in this work, at least 45% of produced hydrogen comes from the steam.

關鍵字

Hydrogen production ； ethanol steam reforming ； tubular fixed-bed reactor

並列摘要

本文以數值方法分析管型固定床乙醇蒸汽重組產氫反應器的性能，探討管的壁溫（T_w）、氣體空間速度（GHSV）及進口水蒸汽／乙醇莫爾比（ψ）的效應。於GHSV = 2000 h^(-1)條件下，結果顯示在高溫壁（T_w = 873K）及ψ=10時，在進口附近的甲烷莫爾濃度大於接近平衡的出口，然而在低溫壁（T_w = 673K）情況下，此現象消失。在低溫壁（T_w = 673K）及ψ= 3的條件下，有高達78.2%的產氣氫來自水蒸汽反應物，此比例隨壁溫增高而顯著減少，在T_w ＜ 852 K之下，有超過一半來自水蒸汽。於ψ= 10時，產氣氫來自水蒸汽便會稍小於來自乙醇，在本文探討的參數範圍，均至少45%產氣氫來自水蒸汽。