本文選題：生物柴油 + 酯交換反應(yīng)　； 參考：《上海應(yīng)用技術(shù)學(xué)院》2015年碩士論文

【摘要】：生物柴油(即脂肪酸甲酯)以其良好的再生性和環(huán)保性正逐漸成為化石燃料的替代品。生物柴油通常是通過(guò)植物油或動(dòng)物油脂與甲醇的酯交換反應(yīng)而制得。催化劑的性能是酯交換反應(yīng)的關(guān)鍵,目前主要集中于多相催化劑尤其是固體堿催化劑的研究。本論文對(duì)生物柴油產(chǎn)物的分析方法進(jìn)行了比較研究；采用燃燒法制備了鈣鋯復(fù)合氧化物固體堿,研究了鈣鋯摩爾比對(duì)固體堿物化性能和催化酯交換反應(yīng)性能的影響,并對(duì)其堿性與催化活性之間的關(guān)系進(jìn)行了初步探討；考察了稀土金屬La對(duì)鈣鋯固體堿的促進(jìn)作用。得到以下主要結(jié)論：1、甘油滴定法測(cè)定生物柴油產(chǎn)率步驟繁瑣,且由于測(cè)定原理上存在一定局限導(dǎo)致重復(fù)性和準(zhǔn)確性不夠理想。色譜法需要大量的標(biāo)準(zhǔn)樣品,測(cè)試時(shí)間較長(zhǎng)。核磁共振法(NMR)相對(duì)簡(jiǎn)單方便且準(zhǔn)確性和重復(fù)性好。2、隨著鈣鋯摩爾比的增加,催化劑的BET比表面減小,表面的總堿性位則先增加后減小,在鈣鋯摩爾比為8：2時(shí),總的堿性位數(shù)量達(dá)最大值。隨著鈣鋯摩爾比的增加,堿位強(qiáng)度逐漸增強(qiáng),并導(dǎo)致TOF值的增大。最佳組成的催化劑在催化劑用量為1.25 wt%,醇油比為25：1,反應(yīng)溫度為65℃的條件下,反應(yīng)時(shí)間為2h和3 h,生物柴油的轉(zhuǎn)化率分別達(dá)到93.9%和98.0%。3、尿素硝酸鹽燃燒法是一種快速有效的制備CaO-ZrO2固體堿催化劑的方法。最佳制備條件為：燃料用量為化學(xué)計(jì)量比的150%,起燃溫度為500℃,燃燒產(chǎn)物不需要進(jìn)一步焙燒。4、La的添加顯著增加了CaO-ZrO2催化劑的BET比表面,增大了孔容孔徑。90%轉(zhuǎn)化率的時(shí)間由2 h縮短至0.5 h。催化活性提高與催化劑的孔徑和比表面變大有關(guān)。5、La的添加提高了CaO-ZrO2固體堿的抗水性和使用壽命。當(dāng)大豆油中含有8.0 wt%的水時(shí),反應(yīng)1h轉(zhuǎn)化率達(dá)90%以上,相同條件下的CaO-ZrO2轉(zhuǎn)化率僅15%。當(dāng)La的添加量為5%時(shí),催化效率為95%,催化劑的循環(huán)使用次數(shù)從3次提高到了6次。
[Abstract]:Biodiesel (fatty acid methyl ester) is becoming a substitute for fossil fuels for its good reproducibility and environmental protection. Biodiesel is usually produced by transesterification of vegetable oil or animal oil with methanol. The performance of catalyst is the key of transesterification, and it is mainly focused on heterogeneous catalyst, especially solid base catalyst. In this paper, the analytical methods of biodiesel products were compared, the solid base of calcium zirconium composite oxide was prepared by combustion method, and the effects of molar ratio of calcium to zirconium on the physicochemical properties and catalytic transesterification of solid bases were studied. The relationship between the alkalinity and the catalytic activity was discussed, and the promoting effect of rare earth metal La on the calcium zirconium solid base was investigated. The main conclusions are as follows: 1. The steps of measuring biodiesel yield by glycerin titration are tedious, and the repeatability and accuracy are not satisfactory due to the limitation of the determination principle. Chromatography requires a large number of standard samples, the test time is longer. Nuclear magnetic resonance (NMR) method is relatively simple and convenient, and has good accuracy and repeatability. With the increase of the molar ratio of calcium to zirconium, the BET specific surface of the catalyst decreases, while the total basic potential of the surface increases first and then decreases, at 8:2 the molar ratio of calcium to zirconium increases. The total number of basic sites reached the maximum. With the increase of the molar ratio of calcium to zirconium, the base potential strength increases and the TOF value increases. The optimum composition of the catalyst is 1.25 wt, the ratio of alcohol to oil is 25: 1, the reaction temperature is 65 鈩，

本文編號(hào)：2108956