《粗甲醇催化氧化制备甲醛的研究》由会员分享，可在线阅读，更多相关《粗甲醇催化氧化制备甲醛的研究（52页珍藏版）》请在金锄头文库上搜索。
1、山东轻工业学院 硕士学位论文 粗甲醇催化氧化制备甲醛的研究 姓名：刘凯 申请学位级别：硕士 专业：应用化学 指导教师：周立国 2011-06-10 山东轻工业学院硕士学位论文 I 摘 要 甲醛是一种重要的基本有机化工原料，用途广泛。甲醛的制备方法有多种，工艺比 较成熟的有甲醇空气氧化法、甲缩醛氧化法。我国主要的甲醛制备工艺是“银法” ，精 甲醇在银催化剂作用下经过氧化、脱氢反应生成甲醛。如果用粗甲醇为原料制备甲醛， 就可以节省精馏能耗，简化操作，降低制备成本，达到节能和提高经济效益的目的。但 是“银法”不应用粗甲醇，这是因为粗甲醇中的杂质可以使电解银催化剂中毒。 测定粗甲醇中杂质成分及甲醇含量
2、，测得本实验所使用粗甲醇的甲醇含量、铁杂质 含量、硫杂质含量、水含量、蜡质含量分别是 56.40%、0.01258 g/mL、0.1739 g/mL、 42.18%、1.1%。 通过气固相催化装置，以电解银催化剂、铁钼催化剂、复合催化剂作为催化剂对 Fe2+、S2-杂质含量不同的甲醇试样催化氧化合成甲醛，测试产品中甲醛产率考察催化剂 活性。当甲醇中 Fe2+杂质浓度小于 1.25810-2 g/L 时，对铁钼催化剂和电解银催化剂活 性较短时间内影响不大，并且铁钼催化剂比电解银催化剂保持活性时间要长。甲醇中 Fe2+杂质浓度达到 3.77410-2 g/L 时两种催化剂所得甲醛产率较低， 催化剂
3、都有所失活， 电解银催化剂比铁钼催化剂更容易受到 Fe2+杂质的影响。S2-杂质浓度小于 1.69910-2 g/L 时，铁钼催化剂活性影响不大，而电解银催化剂受到影响，甲醛产率很低。当 S2- 杂质浓度达到 5.09710-2 g/L 时，铁钼和电解银催化剂催化氧化所得甲醛产率都很低， 须除去 S2-杂质。粗甲醇中 Fe2+、S2-杂质浓度一定，复合催化剂制备甲醛在一定时间内 产率基本不变，说明粗甲醇对这种复合催化剂基本没有影响，复合催化剂可以用粗甲醇 为原料制备甲醛。 测定电解银与复合催化剂催化氧化粗甲醇制备甲醛时最佳工艺条件。 电解银催化氧 化粗甲醇制备甲醛最佳工艺条件是水醇比 60%，
4、氧醇比 0.38，反应温度 540 ，反应时 间 9 h。银与钼的氧化物复合催化剂最佳工艺条件是水醇比 58%，氧醇比 0.44，反应温 度 480 ，反应时间 8 h。银与铝的氧化物复合催化剂最佳工艺条件是水醇比 58%，氧 醇比 0.44，反应温度 480 ，反应时间 8 h。 关键词：关键词：复合催化剂；粗甲醇；杂质；活性 山东轻工业学院硕士学位论文 I ABSTRACT Formaldehyde is an important basic organic chemical material which is very useful. There are several ways of
5、formaldehyde production like air oxidation of methanol, methyl acetal oxidation. The main production process of formaldehyde is the “silver method” in china, which is oxidation and dehydrogenation reaction of methanol under the action of the silver catalyst. Using semifinished methanol as the raw ma
6、terial directly to produce formaldehyde, the new technique could save energy of distillation, simplify operations, reduce production costs, improve the economic efficiency. “silver method” is not good enough to produce formaldehyde by semifinished methanol as the raw material. Because impurities in
7、the semifinished methanol can make electrolytic silver catalyst poison. There is a determination of semifinished methanol. The experiment results obtained that semifinished methanol in this experiment have the content of methanol, iron impurity, sulfur impurity, water, and wax which respectively is
8、56.40% (mass fraction), 0.01258 g/mL, 0.1739 g/mL, 42.18% (mass fraction), 1.1% (mass fraction). The effects of impurities of Fe2+ and S2- in methanol about the activation of the electrolytic silver, Fe-Mo and composite catalyst by catalytic oxidation producing formaldehyde has been investigated on
9、gas-solid catalytic device. Experiment results showed that electrolytic silver catalyst and Fe-Mo catalyst had little effect when the impurities of Fe2+ S2- in methanol lowing. When the methanol concentration of Fe2 + impurity less than 1.25810-2 g/L, the Fe-Mo catalyst and electrolytic silver catal
10、yst activity is not affected in a relatively short time, Fe-Mo catalyst activity keep longer activation than the electrolytic silver catalyst. The two catalysts are inactivated when the impurity concentration of Fe2+ is 3.77410-2 g/L in methanol, electrolytic silver catalyst is more susceptible to t
11、he impact of Fe2+ impurity in fast inactivation than Fe-Mo catalysts. When S2- impurity concentration less than 1.69910-2 g/L, it can not be affected by the Fe-Mo catalyst activity, while the electrolytic silver catalyst will be deactivated. When the S2- impurity concentration is 5.09710-2 g/L, the
12、S2- impurity must be removed. Fe2+ impuritiy concentration less than 1.25810-2 g/L, S2- impurity concentration less than 1.69910-2 g/L in the methanol, Molybdenum oxide and Ag composite catalyst is best of the composite catalyst, Molybdenum oxide and Ag composite catalyst productivity in a certain p
13、eriod of time basically unchanged, indicating that this composite catalyst had no effect by semifinished methanol, Molybdenum oxide and Ag composite catalyst can product formaldehyde by using semifinished methanol ABSTRACT II as raw material. There is a determination of the optimum conditions about
14、electrolytic silver and composite catalysts in catalytic oxidation preparing formaldehyde by semifinished methanol. The obtained optimum conditions of electrolytic silver were reaction temperature 540 , ratio of water and methanol 60%, ratio of oxygen and methanol 0.38, reaction time 9 hours. The op
15、timum conditions of Molybdenum oxide and Ag composite catalyst were reaction temperature 480 , ratio of water and methanol 58%, ratio of oxygen and methanol 0.44, reaction time 8 hours. The optimum conditions of Aluminum oxide and Ag composite catalyst were reaction temperature 480 , ratio of water
16、and methanol 58%, ratio of oxygen and methanol 0.44, reaction time 8 hours. Keywords: composite catalyst; semifinished methanol; impurities; activation 学位论文独创性声明 本人声明，所呈交的学位论文系在导师指导下本人独立完成的研究成果。文中引用 他人的成果，均已做出明确标注或得到许可。论文内容未包含法律意义上已属于他人的 任何形式的研究成果，也不包含本人已用于其他学位申请的论文或成果，与我一同工作 的同志对本研究所做的任何贡献均已在论文中作了明确的说明并表示谢意。 论文作者签名： 日期： 年 月 日 学位论文知识产权权属声明 本人在导师指导下所完成的论文及相关的职务作品，知识产权归属山东轻工业学 院。山东轻工业学院享有以任何方式发表、复制、公开阅览、借阅以及申请专利等权利， 同意学校保留并向国家有关部门或机构送交论文的复印件和电子版，本人离校后发表或 使用学位论
