【作者】 熊伟；

【导师】 马美湖；

【作者基本信息】 华中农业大学 ， 农产品加工及贮藏工程， 2010， 硕士

【摘要】 本研究以天然高级脂肪醇和环氧乙烷为原材料,合成制取环氧乙烷高级脂肪醇(OHAA)农产品保鲜新材料。OHAA合成的难点是合成反应催化剂的选择,本文通过研究找出了催化OHAA合成的高效催化剂,并对催化合成反应的工艺进行了优化,研究结论主要如下：确定了Mg/Al/Co复合金属氧化物最佳的煅烧温度为500℃,在此温度下煅烧的催化剂具有很好的多孔结构,有利于催化OHAA的合成。通过比较得出了镁铝比为3：1的Mg/Al/Co复合金属氧化物具有最佳的催化性能。Mg/Al/Co复合金属氧化物都具有很大的比表面积,当Mg:Al=3:1时比表面积为235,具有最大比表面积。研究了催化剂用量、反应温度、反应压力对Mg/Al/Co复合金属氧化物催化OHAA合成反应的影响,用响应面分析法得出最佳的反应条件：催化剂用量2.5%,反应温度158℃,反应压力0.5 MPa,此时的反应速度为9.08 g／h,产物分子量分布为90%。通过研究表明Mg/Al/Co复合金属氧化物具有很好的重复利用性,为环境友好型催化剂。通过与传统KOH催化剂比较,Mg/Al/Co复合金属氧化物催化剂在反应速度上不如KOH,但是产物性能在过方面都超过了KOH。对Mg/Al/Co复合金属氧化物催化合成产物做红外分析,红外图谱与我们设计产物的分子式相符。对Mg/Al/Co复合金属氧化物催化的OHAA进行了薄层色谱分析,分析得出产物具有很好的窄分布效果,而且副产物PEG的含量低,产物中没有未反应的高级脂肪醇。根据转化率与时间变化曲线找到以Mg/Al/Co复合金属氧化物为催化剂时,符合动力学方程的反应阶段的分界点为63%。通过拟合1nP与时间曲线可以得到以Mg/Al/Co复合金属氧化物为催化剂时,不同温度下的反应速率常数,根据阿仑尼乌斯方程求出反应的活化能为：67.7 KJ/mol。通过不同的合成路线合成了五种Fe-Zn双金属配合物催化剂,首先对这些催化剂做了XRD表征,得出以1,4-二氧六环为配位体的催化剂的结晶度高于以叔丁醇为配位体的催化剂；K3Fe(CN)6和有机配体的混合溶液滴入ZnCl2溶液中得到的催化剂相比其它路径合成的催化剂结晶度更高；将配位体预先加入合成起始剂中可以得到结晶度更好的催化剂。比较了五种Fe-Zn双金属配合物催化剂的催化活性得出合成高分子量的OHAA时,适宜的滴加顺序为将K3Fe(CN)6溶液和有机配体的混合溶液滴加到ZnCl2溶液；合成小分子量的OHAA则将ZnCl2溶液滴加到K3Fe(CN)6溶液,这样可以缩短诱导期的时间。以1,4-二氧六环为配位体的Fe-Zn双金属配合物催化剂催化OHAA合成的速度达到了14.3g/h。Fe-Zn双金属配合物络合1,4-二氧六环催化剂催化OHAA合成100℃为最合适的温度,催化OHAA反应产物的窄分布程度也非常高的。更多还原

【Abstract】 In this thesis, the natural fatty alcohol and ethylene oxide were used to synthesize fatty alcohol ethylene oxide (OHAA), which was a new agriculture products freshing material. The nodus of synthesis reaction is to search a high performance catalyst. The efficient catalyst of synthesis OHAA were found out in this article. The main results are as follows:The best calcination temperature of Mg/Al/Co composite metal oxides is 500℃. Calcination at this temperature the catalyst owned a good porous structure and formed the internal crystal structure. The ratio of Mg:Al at 3:1 Mg/Al/Co composite metal oxide owned the best catalytic performance. Mg/Al/Co composite metal oxides owned the greatest surface area of 235 when Mg:Al at 3:1. The impact of the amount of catalyst, reaction temperature, reaction pressure in Mg/Al/Co composite metal oxide catalyst synthesis OHAA were researched. The optimized conditions of Mg/Al/Co composite metal oxide catalysis OHAA synthesis were:catalyst amount of 2.5%、temperature 158℃、pressure 0.5 Mpa and the reaction speed was 9.08 g/h, the distribution of OHAA was 90%. Mg/Al/Co composite metal oxides is environmental-friendly catalyst, wich is with good re-use nature and non-toxic pollution. By comparison with conventional KOH catalyst, Mg/Al/Co composite metal oxide catalyst synthesis OHAA have a less speed which is due to strong alkaline of KOH, but the performance of product is better than KOH. Analysis the product catalyst by Mg/Al/Co composite metal oxide by IR spectra and the product on line is matched with we designed. Thin-layer chromatography analysis reveals that the product catalyst by Mg/Al/Co composite metal oxide owned the narrow distribution and low content of PEG-product, and the product of unreacted higher fatty alcohol is not exist. According to the conversion rate the cut off point in Mg/Al/Co composite metal oxide catalyst synthesis OHAA is 63%, which is in line with the response phase of the dynamic equation. We can find the rate constant at different temperatures of Mg/Al/Co composite metal oxide catalyst synthesis OHAA by LnP and time curves. According to Arrhenius equation, activation energy of reaction is 67.7 KJ/mol by fitting 1nK and 1/T curve. Five kinds of Fe-Zn double metal complex catalyst were synthisized through XRD analyze, which have different synthetic route and obtained that 1,4-dioxane ligand catalyst for the degree of crystallinity higher than tert-butyl alcohol as a catalyst ligand; K3Fe (CN) 6 and a mixed solution of organic ligands in solution instilled ZnCl2 catalyst for the synthesis of catalyst was with high crystallinity, compared with other paths; the synthesis of ligands from the pre-accession can be better crystallinity of the catalyst before agents. Comparison of five Fe-Zn double metal complex catalytic activity obtained when the synthesis of high molecular weight OHAA, the appropriate order of dropping is the K3Fe (CN) 6 solution and the organic ligand mixture added to ZnCl2 solution; synthesis of low molecular weight OHAA, ZnCl2 solution was added to K3Fe (CN)6 solution, this can shorten the induction period of time.1,4-dioxane as the ligand of Fe-Zn double metal complex catalysts, and OHAA synthesis rate reached 14.3 g/h. Fe-Zn complex double metal complexes of 1,4-dioxane catalyst OHAA for the synthesis,100℃was the most suitable temperature, catalyst OHAA narrow distribution of reaction products have a very high level.更多还原