|英文摘要: ||Methylal has drawn more and more attention due to its non-toxic, low water content and similar chemical properties to formaldehyde. A series of value-added fine chemicals such as methyl methoxy acetate and formaldehyde could be synthesized with methylal as the main feed. In this thesis, the practical significance and the recent developments of the synthesis of methyl methoxy acetate and formaldehyde are reviewed briefly, from which the research ideas of the present work, e.g. synthesis of methyl methoxy acetate and formaldehyde, are derived. And the main contents and conclusions are listed as follows:① Synthesis of methyl methoxy acetate① A method for detecting different reactants and products was developed through a series of experiments. Relative correction factors to methylal of different constituents were ascertained. The contents of different reactants and products were calculated by means of area normalization method, which enabled the calculation of conversion and selectivity. ② The coupling reaction of methylal and formic acid was studied. The products were characterized by GC-MS to be methyl methoxy acetate. ③ The effects of several acid catalysts such as cationic resin, molecular sieves and P-toluene sulphonic acid were explored in the batch autoclave. No methyl methoxy acetate was detected when the reaction was performed without a catalyst. P-toluene sulphonic acid showed the best result among those acid catalysts.④ The effect of reaction conditions such as reaction temperatures, reaction time, mole ratio of reactant and catalyst/methylal mass ratio on the methyl methoxy acetate synthesis has been investigated. And the optimized reaction conditions are 0.36 mole ratio of methylal to formic acid, 0.018 catalyst/methylal mass ratio, 140℃ reaction temperature and 4 h reaction time. Under the optimized reaction conditions, 87.5% methyl methoxy acetate could be achieved.⑵ Study on the preparation of formaldehyde by means of the surface reaction of methylal oxidation.① A series of catalysts of Al2O3 supported Fe, Mo and Fe-Mo were prepared by an impregnation technique.② The surface reaction of formaldehyde synthesis was carried out with varied catalysts under different reaction conditions by the temperature program surface reaction (TPSR) techniques and the on-line mass spectrometer. The results showed that there were many side reactions besides the main reaction.③ The results of TPSR showed that the catalyst of Al2O3 supported Fe-Mo was better than the catalysts of Al2O3 supported Fe or Mo respectively. ④ The quality of formaldehyde came to the maximum when the reaction temperature was 50 oC.|
|Appears in Collections:||新疆维吾尔自治区精细化工工程技术研究中心_学位论文|
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沈鑫权. 由甲缩醛合成甲氧基乙酸甲酯及高浓度甲醛研究[D]. 北京. 中国科学院大学. 2013.