聚甲氧基二甲醚合成的酸性树脂催化剂的研究

发布时间：2018-04-04 16:50

  本文选题：甲醇　切入点：甲醛　出处：《西北大学》2017年硕士论文

【摘要】：将聚甲氧基二甲醚用作柴油添加剂使用,与柴油组成混合燃料。使用时具有环保及高效性能,可有效节能减排。本实验使用低成本原料甲醇、甲醛及低成本催化剂酸性树脂进行合成研究,旨在为聚甲氧基二甲醚的生产提供一个新的路线。本文合成实验使用甲醇、甲醛在酸性树脂催化剂上合成聚甲氧基二甲醚。本文的主要工作为催化剂研究和合成工艺条件考察。在催化剂研究中,首先筛选树脂催化剂,在催化机理分析基础上,在树脂引入含有质子酸的酸性基团,并在此基础上再次引入路易斯酸改性催化剂酸性,同时考察催化剂再生条件。并对其合成工艺进行优化,得到优化的工艺条件。首先,讨论了甲醇甲醛合成聚甲氧基二甲醚的催化反应机理,是在酸性树脂催化下的缩醛化反应。本实验对部分市售酸性树脂进行筛选,实验结果显示:聚合反应时强酸性树脂D001催化效果较优。甲醇转化率为43.5%,产物选择性为40.8%。其次,以聚苯乙烯白球树脂作为底物,对催化剂进行酸化。使用浓硫酸、发烟硫酸、氨基磺酸、浓磷酸和醋酸对白球树脂进行酸化,调节催化剂的酸性。结果表明:发烟硫酸制备出的强酸性树脂具有较高的催化活性。聚合反应甲醇转化率为45.8%,产物选择性为46.3%。在此基础上对强酸树脂引入路易斯酸进行改性,继续优化其酸性。使用结果表明:以FeCl3为改性剂时性能最佳。聚合反应甲醇转化率为53.0%,产物选择性为49.0%。对强酸树脂和路易斯酸改性的催化剂进行表征,表明改性催化剂改性基团稳定的结合到树脂上,改性未影响树脂自身结构,且改性后其酸强度降低、酸中心数量增多。使用FeCl3改性催化剂对PODEn的反应工艺条件进行了考察。最优条件为:反应温度控制在90～96℃范围内,压力1.0MPa,物料比n(CH2O):n(CH3OH)=3:1,重时空速1.5h-1。聚合反应甲醇转化率和产物选择性分别为57.0%和52.8%。最后对强酸性树脂催化剂失活再生进行探索。采用盐酸对失活催化剂进行再生,通过催化剂表征,推断催化剂失活的主要方式是磺酸基团中H+的损失,通过盐酸再生可得到效果较佳的再生催化剂。
[Abstract]:Poly (methoxy) dimethyl ether was used as diesel additive and mixed with diesel oil.Use with environmental protection and efficient performance, energy saving and emission reduction can be effective.In this experiment, methanol, formaldehyde and low cost catalyst acid resin were used to synthesize polymethoxy dimethyl ether, which provided a new route for the production of poly (methoxy) dimethyl ether.In this paper, methanol and formaldehyde were used to synthesize poly (methoxy) dimethyl ether over acid resin catalyst.The main work of this paper is the study of catalyst and the investigation of synthetic conditions.In the study of catalyst, the resin catalyst was first screened, and the acidic group containing proton acid was introduced into the resin on the basis of the analysis of the catalytic mechanism, and the acid of the Lewis acid modified catalyst was introduced again on this basis.At the same time, the conditions of catalyst regeneration were investigated.The synthetic process was optimized and the optimized process conditions were obtained.Firstly, the catalytic mechanism of synthesis of poly (methoxy) dimethyl ether from methanol and formaldehyde was discussed.The results showed that the catalytic effect of strong acid resin D001 was better in polymerization reaction.The methanol conversion was 43.5 and the selectivity of the product was 40.8.Secondly, the catalyst was acidified with polystyrene white ball resin as substrate.Acid was acidified with concentrated sulfuric acid, fuming sulfuric acid, amino sulfonic acid, concentrated phosphoric acid and acetic acid to regulate the acidity of the catalyst.The results showed that the strong acid resin prepared by fuming sulfuric acid had high catalytic activity.The conversion of methanol was 45.8 and the selectivity of the product was 46.3.On this basis, the strong acid resin was modified with Lewis acid, and its acidity was optimized.The results show that FeCl3 is the best modifier.The methanol conversion of polymerization was 53.0 and the selectivity of the product was 49.0.The strong acid resin and Lewis acid modified catalyst were characterized. The results show that the modified catalyst can bind to the resin stably, and the modified catalyst does not affect the structure of the resin, and the acid strength of the modified catalyst decreases and the number of the acid center increases.The reaction conditions of PODEn were investigated by using FeCl3 modified catalyst.The optimum conditions are as follows: the reaction temperature is controlled in the range of 90 鈩，

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