改良之下抽式氣化爐應用於稻殻之產氣品質與發電效率之研究

Experimental Study of Electric Generator Efficientcy by Using rice husk gasification in improved downdraft gasifier

林學誠(Chea-Seng Lim)

指導教授 ： 馬小康

國立臺灣大學/工學院/機械工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.01897

摘要

在過去十年，生質廢棄物之氣化研究文獻數量一直不斷增加。而在日本福島核災之後，能源議題更加被重視。米一直都是亞洲地區的主食，目前已經有上千頓的稻殼廢棄物在不斷產生。鑒於此問題的重要性而成為本論文的主要研究目的。稻殻的含碳量介於40%∼50％。本研究使用了小型生質氣化爐來評估氣化效能中的氧碳比，特別是氫氣產量。然而混合氣體（H_2, CO, CO_2, and CH_4），高熱值（HHV），氣體產率，能量轉換效率（ECE）等這些氣化的總效能都會在本論文中列出討論。
然而有些氣化爐的設計問題，如熱散失，連續除焦油與氣密問題等。此研究的目的是改善市售氣化爐的缺陷以及使用稻殻作為燃料在不同狀況下的測試。在此研究所顯示的穩定燃燒溫度介於800℃∼1100℃，同時研究中發現當當量比於0.3時可得到HHV與氫氣的最佳值，即為5.71(MJ/m^3)與26.53vol %，足以證實稻殼為非常適用之生質燃料。
後端之餘熱使用熱電片將熱能轉換為電能，當溫差在52度時效率為1.4%，但當上下溫差達到160℃時為最佳值，為3.2%，能將後端之餘熱進行有效且長時間連續發電。

關鍵字

生質燃料 ； 氣化 ； 當量比 ； 高熱值 ； 冷媒器效率 ； 熱電材料

並列摘要

Energy problem has become an important issue after Fukushima Daiichi nuclear disaster and the gasification of biomass wastes was increasingly studied in the last decade. Since rice is the stable food, there is thousands tons of rice husk dumped as wastes. Therefore, rice husk were used as experimental subject in this study. Carbon contents of the above biomass are in the range of 40% to 50%. The gasification of biomass was carried out in the lab-scale gasifier in order to evaluate the effect of O/C ratio on the gasification performance, especially the hydrogen production. Also, the gas composition (H_2, CO, CO_2, and CH_4), high heating value (HHV), gas production rate, and energy conversion efficiency (ECE) to assess the total efficiency of the gasification will be discussed.
Furthermore, there are some problem because of gasifier design, like heat dissipation, tar accumulation continuous feeding problem, and the leakage etc. The aim of this study was improved the defect of commercial available gasifier and select rice husk as fuel to test in different conditions. Results of this study showed the improved gasifier can carry out steady combustion zone around 800℃ to 1100℃, moreover, we found when the equivalence ratio is 0.3, the HHV and hydrogen concentration had the optimum efficiency is 5.71(MJ/m^3) and 26.53vol %. Rice husk has a great potential as a biofuel.
In this study using thermal electric generator to translate thermal energy into electric energy, the translate efficiency are 1.4% when thermal different up to 52 degree. The best efficiency 3.2% are located in temperature different of 160 degree. That can make the IGCC waste heat fully used in length period.

並列關鍵字

Biomass ； Gasification ； Equivalence ratio ； High Heating Value ； Cold Gas Efficientcy ； Thermal Electric Generator

參考文獻

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