液態酒精燃料應用於中溫SOFC之研究

Abstract

液態碳氫燃料有著體積能量密度高於氫氣的優勢，是應用在固態氧化物燃料電池上具經濟及能源效益之燃料，如何有效利用液態碳氫燃料，了解此項能源技術發展之成本結構，是發展永續能源的一個挑戰。本研究將甲醇與乙醇氣化，研究經氣化和重整後，測試合成氣中3種小分子燃料(H2, CO和CH4)的含量。研究利用兩種系統的重整用催化劑，分別以活性氧化鋁球與氧化鐵為陶瓷載體，氧化鎳、氧化鈰、氧化釤與氧化鐵等為催化材，利用氣相層析儀進行重整後合成氣之定量分析，探討不同陶瓷催化劑成分對重整氣體成分的影響。為了能應用於中溫SOFC，並長時間運轉，本研究組製一加熱爐進行電與熱的測試，並透過將實驗步驟和原料等分類歸納，探討實驗室級之液態碳氫燃料用於SOFC發電之可行性，並進行成本估算。本研究之催化載體用於重整反應後，在800 oC約可產出34%一氧化碳、58%氫氣以及4%甲烷，在能量轉換效率為50%、700 W SOFC電池堆之成本40000元、總持溫時間20000小時與催化劑壽命為10天之假設下進行估算，本研究並討論廢氣之熱回收、內重整及採用廢棄燃料(PP40)之對於發電成本之影響。

Liquid hydrocarbon fuels have the advantage of higher volumetric energy density over hydrogen. The fuels are economic and energy-efficient if used for portable solid oxide fuel cells (SOFCs). This study investigates the gasification and reforming of bio-alcohols and trying to understand the cost structure of the energy technology which is necessary and sustainable for our energy development. Methanol and ethanol were gasified, and the content of three small molecular fuels (H2, CO, and CH4) in the syngas were studied. Two systems of reforming catalysts were used, activated alumina balls and iron oxide as ceramic carrier, nickel oxide, cerium oxide, samarium oxide, and iron oxide as catalytic materials. Using gas chromatography (GC) to quantitatively analyze the reformed syngas was conducted, the effects of different ceramic catalyst components are discussed. In order to operate the IT-SOFC for a long period, we assembled a furnace for conducting electrical and thermal tests. Through classification and collection of assembling steps, raw materials costs, we calculated the costs of using liquid hydrocarbon fuels for the power generation of SOFC. The catalyst used in this study can produce about 34% CO, 58% H2 and 4% CH4 at 800 oC, with several assumptions, including energy conversion efficiency 50%, a cost NT$40,000 of a 700 W SOFC, total operation time 20,000 hr, and the catalyst lifetime lasting for 10 days. Several amendments, heat recovery from waste gas, internal reforming, and using low-cost waste plastic/paper mixture (PP40) are discussed based on the influence on the cost of the power generation.