一步法合成二甲醚催化剂失活的研究进展

Progress in Catalyst Deactivation Study for Direct Synthesis of Dimethyl Ether

综述了一步法合成二甲醚催化剂的失活原因及解决方法。复合催化剂中任一组分的失活都会造成整个催化剂的失活。Cu基合成甲醇催化剂的毒物主要为S,C l,Fe,N i等,净化原料气,控制原料气中S和C l的含量,采用不锈钢设备可延缓催化剂中毒;活性组分烧结是复合催化剂失活的重要原因,通过控制反应温度、导出反应生成的水及改进催化剂制备方法可提高催化剂的稳定性;活性组分的迁移、流失、积碳等也是催化剂失活的原因。甲醇脱水催化剂的失活主要由积碳及结构破坏造成,通过改性提高催化剂的抗积碳和抗水性能可以延长催化剂的使用寿命。

The causes and solutions of the catalyst deactivation for the direct synthesis of dimethyl ether from syngas were reviewed. Deactivation of either component in the composite catalysts could lead to the catalyst deactivation. Microimpurities, namely S, Cl, Fe and Ni, could cause the catalyst deactivation, which could be prevented by purification of the raw gas and using stainless steel equipments. Sintering of the Cu in the catalysts was an important problem which led to the catalyst deactivation. The catalyst stability could be enhanced by controlling the reaction temperature, removing the water generated by the reaction and modifying the catalyst preparation methods. Transfer and loss of the active components, and the coking on the catalysts were also the causes of the catalyst deactivation. The deactivation of methanol dehydration components was mainly caused by the coking and the catalyst structure damaging. Life of the catalysts could be prolonged by improving the resistances of the catalysts to the carbon deposition and water.