甲醇進料量及過量空氣對快速催化燃燒器暫態溫度分佈之影響

Effect of Methanol Feed Rate and Excess Air on Transient Temperature Profile of a Rapid Catalytic Combustor

徐俊平(Chung-ping Hsu)

指導教授 ： 洪賑城

大同大學/工程學院/化學工程學系所/碩士(2008年)

摘要

本研究目的為探討空間速度、過量空氣及進料方式對快速催化燃燒器在冷啟動時之暫態溫度分佈之影響。快速催化燃燒器係利用兩支同心不鏽鋼管製成截面為環形之反應器，並填充Pt/BN/γ-Al2O3觸媒於環形區域。內環配置熱電偶，共30支；外環則配置12支。所有溫度訊號每秒擷取一次，並紀錄於電腦中，以了解催化燃燒器之快速溫度變化。
甲醇燃燒實驗結果顯示，在WHSV為0.147h-1，過量空氣為20%時，快速催化燃燒器可以在5分鐘之內由室溫提升到200℃，20分鐘達420℃，3小時後達682℃。
實驗結果亦顯示WHSV越大，快速燃燒器之溫度越高；過量空氣越大，快速燃燒器進出口溫度差越小；由燃燒器上端進料之燃燒效果較下端進料佳。
所有實驗之溫度分佈皆有再現性，代表實驗數據可用，且觸媒亦無退化現象。利用氣相層析儀分析燃燒器出口氣體，發現在反應初期，燃燒尚未完全，水及甲醇會吸附在燃燒器後端溫度較低之觸媒上，在反應中期，前述吸附之水及甲醇會脫附，同時造成燃燒器末端溫度有兩次升溫之現象。

關鍵字

快速催化燃燒器 ； 甲醇

並列摘要

It is the objective of this research to study the effect of space velocity, excess air and feeding position on transient temperature profiles of a rapid catalytic combustor (RCC) during cold start-up. The RCC was made by two concentric stainless-steel tubes, with Pt/BN/γ-Al2O3 catalyst filled in the annual area. There are 30 thermocouples in the inner side and 12 around the outer side. All the temperature signals were acquired every second in order to record the quick change of the temperature profile of RCC in the computer.
Experimental results of methanol combustion show that when WHSV is 0.147 h-1 and excess air is 20%, the temperature of RCC can be raised from room temperature to 200℃ in 5 min, 420℃ in 20min, and 682℃ in 3h. The results also show that temperature of RCC increases with increasing WHSV; increasing excess air decreases the temperature difference between the inlet and outlet of RCC; and feeding at the top of RCC has better combustion than feeding at the bottom does.
Reproducibility of temperature profile has been obtained for the combustion of methanol in RCC, indicating the experimental data is feasible and the catalyst does not deactivate. Analysis of outlet gas composition by GC reveals that at the initial stage of reaction, combustion is not completed, and water and methanol adsorb on the low-temperature catalyst at the rear part of combustor; at the middle stage of reaction, abovementioned water and methanol desorb from the catalyst. In the meantime, it results in a two-stage temperature increase at the rear part of the catalytic combustor.

並列關鍵字

Rapid Catalytic Combustor ； Methanol

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