微波電漿技術應用於甲烷重組之研究

Reforming of Methane Using Microwave Plasma Techniques

黃曉鳳(Hsiao-Feng Huang)

指導教授 ： 魏大欽

中原大學/工學院/化學工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100235

摘要

摘 要

本研究利用氧氣於微波電漿反應器對甲烷進行重組實驗，以傅利葉轉換紅外線光譜儀及氣相層析儀分析產物（氫氣、一氧化碳、二氧化碳、乙烷、乙烯和乙炔）組成並據以計算甲烷和氧氣轉化率及產物選擇性，探討甲烷/氧氣進料比、微波功率、操作壓力和進料流量等操作參數對甲烷轉化率和產物選擇性之影響；另外，結合數學模型以瞭解甲烷/氧氣在微波電漿中之反應機構。

實驗結果發現，加入氧氣能有效提昇甲烷轉化率，且氧氣進料含量影響產物H2/CO之值甚大，在氧氣添加10%時可達最高（約5.4）；提高微波功率可增加甲烷轉化率與氫氣選擇性，一氧化碳選擇性則下降；操作壓力增加，甲烷轉化率上升，氫氣選擇性下降，一氧化碳選擇性上升，C2產物以乙炔選擇性最高；增加進料流量使得甲烷轉化率和氫氣選擇性下降，一氧化碳選擇性則先升後降。

模擬結果中，於不同之甲烷/氧氣進料配比下，模型計算之甲烷轉化率與產物選擇性與實驗值非常相近，證明反應機構及其速率常數合理；於敏感性分析中發現，產物氫氣主要除了由電子或氫原子與甲烷、乙烷和乙烯反應而來，H+CH2O→H2+CHO亦為非常重要之氫氣生成反應，而一氧化碳之生成主要是經由CHO+M→CO+H+M反應；水氣的加入，雖可增加氫氣生成量，但對產物選擇性分布並無太大之影響。

關鍵字

重組 ； 微波電漿 ； 甲烷

並列摘要

Abstract

Reforming of methane via oxygen plasma in a microwave plasma reactor was investigated. A series of experiments were conducted to determine methane conversion and product distributions over wide ranges of operating parameters. In the meanwhile, a mathematical model was developed to characterize the chemical reactions taking place in methane/oxygen plasmas. The model results were then compare with experimental measurements.
Experimental results showed that methane could be effectively converted in methane/oxygen plasmas. The CH4/O2 ratio had extremely large effect on H2/CO ratio in the effluent. An increase in microwave power resulted in increases of methane conversion and hydrogen selectivity, but carbon monoxide selectivity was decreased. When operating pressure increased, methane conversion and carbon monoxide selectivity were increased, but the selectivity of hydrogen was decreased. Increasing of feed flow rate reduced the residence time of methane, so that the methane conversion and hydrogen selectivity were decreased.
In the modeling studies, it was found that the predictions of methane conversion and product selectivity agreed well with experimental data over a wide range of O2 feed percentage. Sensitivity tests showed that the hydrogen product was not only formed by electron-impact dissociation or H-atom abstraction of hydrocarbons, but also by the reaction of H+HCHO→H2+CHO. However, the formation of carbon monoxide was primarily attributed to the reaction of CHO+M→CO+H+M. The electron impact dissociation of CO2 is not important in CO production.

並列關鍵字

microwave ； methane ； reforming ； plasma

參考文獻

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