常压微波电浆转化乙醇产氢之研究-国立高雄应用科技大学化学工程与.doc

中文摘要 乙醇 (C2H5OH) 具製造容易與易取得的特性，但不易轉化生成氫氣。本研究因此利用常壓微波電漿，進行乙醇裂解與部份氧化產製氫氣。實驗探討乙醇與氧氣之進料位置 (共振腔的上游或下游) 與氧氣/乙醇進流比例 (R)，分別對乙醇轉化率、氫氣選擇率，以及能量消耗率之影響。並以質譜儀分析乙醇、氣相層析儀分析氫氣、傅立葉轉換紅外線光譜儀分析氣相副產物。並經由X光繞射分析儀、化學分析電子光譜儀與穿透式電子顯微鏡，鑑定固態產物的特徵。 實驗結果顯示，較高的R，乙醇轉化率較高；然而較低的R，且乙醇與氧氣均由上游進料下，可獲得較低的產氫能量消耗率。裂解反應顯示，在1.2 kW, [EtOH]in = 5.9%, 13.2 slm，且乙醇由上游進料下之乙醇轉化率為80.4%，氫氣選擇率為70.9%，產氫能量消耗率為14.3 eV/molecule-H2。 部份氧化乙醇則顯示，乙醇與氧氣均上游進料，且R = 0.5時，可達較裂解為佳之成果，轉化率達99.2%，氫氣選擇率達94.9%，產氫能量消耗率為8.46 eV/molecule-H2。 在氣態副產物方面，乙醇裂解或部份氧化以CO為主要產物，其他產物濃度除CO2外，其高低順序為C2H2 C1 CH4 C2H4 HCN。固態副產物方面，無論乙醇或氧氣進料位置為何，裂解或部份氧化，均以碳黑為主要產物，其結構屬於石墨-菱方晶，晶粒大約7 nm，顆粒大小介於10-30 nm。最後，光學發射光譜顯示，活性的N2物種於乙醇電漿反應中，扮演能量傳遞的主要角色之一，而H, OH, CH及N2之光譜強度與乙醇轉化率成正相關。 英文摘要 Ethanol (C2H5OH) is easily produced, while is difficult for producing hydrogen. In this study, plasma pyrolysis and partial oxidation of ethanol to hydrogen-rich fuel by using atmospheric-pressure microwave plasma were carried out. The effects of operational parameters, including the feeding position of reactants (upstream or downstream of resonance cavity) and the inlet O2/EtOH molar ratio, on the conversion of ethanol, selectivity of hydrogen, and energy consumption, were evaluated. A mass spectrometer, a gas chromatograph and a Fourier transform infrared spectrometer were used to determine the ethanol conversion and the concentrations of H2 and other gaseous by products. Moreover, XRD and TEM were used to indentify the solid product. Experimental results showed that a higher ethanol conversion can be achieved at a higher O2/EtOH molar ratio. Moreover, both ethanol and oxygen were fed from the upstream of resonance cavity, the lower energy consumption was performed. By plasmalysis, the conversion of ethanol was 80.4% with a hydrogen selectivity of 70.9% and a energy consumption of 14.3 eV/molecule at 1.2 kW, [EtOH]in = 5.9%, 13.2 slm by feeding ethanol from the upstream. By partial oxidation of ethanol, when ethanol and oxygen were fed from the upstream at O2/EtOH = 0.5, the conversi