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在实验室中,以乙醇脱水制备乙烯,一般使用液体型催化脱水剂和固体接触催化剂二种。属于液体型催化脱水剂中,浓硫酸的使用较为普遍。即是将一份乙醇和三份浓硫酸混合,于170℃反应来实现的。但是生成物中乙烯产量较低,并付产相当数量的乙醚以及二氧化硫。况且,象浓硫酸这样的腐蚀性液体的存在,便给制备、演示等实验操作带来了若干缺点和不安全性。在固体型接触催化剂中,常用的有活性氧化铝和吸收(或悬浮)在多孔性固体载体※1上的磷酸。(其它还有:高岭土、陶土以及石墨等,于较高温度下,也具有一定的催化脱水效能)二者催化脱水效能较高。利用它们对乙醇催化脱水生成乙烯的反应,是将乙醇的蒸气与温度为360℃—380℃的活性氧化铝(或磷酸)接触而完成的:
In the laboratory, the dehydration of ethanol to produce ethylene, the general use of liquid-type catalytic dehydrator and solid contact catalyst two. Is a liquid type of catalyst dehydration agent, the use of concentrated sulfuric acid is more common. That is, a mixture of ethanol and three parts of concentrated sulfuric acid at 170 ℃ to achieve. However, the production of ethylene production is lower, and to pay a considerable amount of ether and sulfur dioxide. Moreover, the presence of corrosive liquids such as concentrated sulfuric acid poses several drawbacks and unsafe to experimental operations such as preparation, demonstration and the like. Among solid type contact catalysts, activated alumina and phosphoric acid absorbed (or suspended) on a porous solid support * 1 are commonly used. (There are also: kaolin, clay and graphite, at higher temperatures, but also has a certain catalytic dehydration efficiency) both high catalytic dehydration. Their use in the catalytic dehydration of ethanol to ethylene is accomplished by contacting the vapor of ethanol with activated alumina (or phosphoric acid) at a temperature of from 360 ° C to 380 ° C: