氧化铝负载杂多酸催化甲醇脱水制备二甲醚

Dimethyl ether preparation by methanol dehydration catalyzed by alumina-supported heteropoly acid

制备并用N2 吸附和吡啶吸附红外进行表征 ,结果表明氧化铝负载杂多酸催化剂具有中孔结构 ,表面上具有布朗斯台特酸和路易斯酸。研究了反应压力、温度和质量空速对甲醇脱水生成二甲醚转化率和选择性的影响 ,及催化剂使用寿命。使用该催化剂制备二甲醚的最佳工艺条件为 :反应压力 0 .75～ 0 .85MPa ,反应温度 2 80～ 32 0℃ ,质量空速 1 .5～ 2 .5h- 1 。

The alumina supported heteropoly acid catalyst is prepared and characterized by N 2 adsorption and pyridine adsorption IR. The results show that the catalyst features porous structure and there are Bransted acid and Lewis acid on its surface. Effects of reaction pressure, temperature and mass space velocity on the conversion and selectivity of dimethyl ether prepared by methanol dehydration and the life span of catalyst are studied. Optimal process conditions for dimethyl ether preparation using the catalyst are as follows: reaction pressure 0.75～0.85 MPa, reaction temperature 280～320℃ and mass space velocity1.5～2.5 h -1 .