水热催化制备绿色柴油工艺中催化剂的失活与再生

Deactivation and regeneration of heterogeneous catalysts in green diesel production by hydrothermal process

近年来,水热催化制备绿色柴油的工艺广受关注,非均相催化剂用于该工艺可以提高绿色柴油的产率和选择性,但催化剂使用过程中常存在失活和再生困难等问题。本文首先介绍了水热催化工艺中常用的催化剂,随后阐述了该工艺中非均相催化剂的失活机理;分别讨论了负载金属和载体对催化剂活性的影响。负载金属的浸出和烧结是引起催化剂失活的重要原因,载体自身不稳定是催化剂失活的另一个重要原因。然后,总结了水热催化工艺中失活催化剂的再生方法,主要包括煅烧和洗涤。最后,对水热催化制备绿色柴油工艺提出了建议,即开发更优质的催化剂、探求更高效的再生方法和选择更适宜的反应条件等。

In recent years,the process of green diesel production by hydrothermal catalysis has attracted much attention.while heterogeneous catalysts can improve the yield and selectivity of green diesel,the regeneration of deactivated catalysts is still a challenge.First,the catalysts widely used in the hydrothermal catalysis process are introduced.Second,the deactivation mechanism of heterogeneous catalysts is discussed,including the metals and the supports.The leaching and sintering of the supported metal are responsible for the deactivation of the catalyst,and the instability of the supports is an important reason.Then,the regeneration methods for the deactivated catalysts are summarized,including calcination and washing.Finally,suggestions are made for the catalytic hydrothermal preparation of green diesel,i.e.,to develop catalysts with high activity,to find efficient regeneration methods,and to select suitable reaction conditions.