Method for preparing pentene

Abstract

The invention relates to a method for preparing pentene, which comprises the following steps of: (1) mixing a piperylene-rich C-5 fraction and hydrogen and then the mixture being sent to a fixed bed catalytic hydrogenation reactor for a selective catalytic hydrogenation reaction in the presence of a catalyst Pd / Al2O3, wherein the molar feed ratio of hydrogen to diolefin in the material is 1- 3:1, the weight hourly space velocity is 1-8hr<-1>, the reaction pressure is 10-20bar, and the reaction temperature is 30-90 DEG C, and the piperylene contained in the material is converted into 1-pentene and 2-pentene by hydrogenation; (2) by utilizing the difference in boiling point of each component in the hydrogenated material, separating the 1-pentene in a distillation column with the number of theoretical plates of 80-100 at a bottom temperature of 55-80 DEG C, a top temperature of 40-60 DEG C, a reflux ratio of 10 to 30 and a column operating pressure of 2-5bar; and (3) then sending a bottom liquid to a distillation column with the number of theoretical plates of 80-100 to separate the 2-pentene at a bottom temperature of 62-87 DEG C, a top temperature of 47-67 DEG C, a reflux ratio of 10 to 30 and a column operating pressure of 2-5bar. The method provided by the invention has the advantages that 1-pentene and 2-pentene products with the purity of more than 98.5% can be easily produced by hydrogenation and distillation methods.

Description

technical field [0001] The present invention relates to a kind of preparation method of pentene, particularly relate to the carbon five distillate that is rich in piperylene and hydrogen are mixed through Pd / Al 2 o 3 The catalyst bed layer is used to selectively hydrogenate piperylene into a mixture of 1-pentene and 2-pentene, and then obtain 1-pentene and 2-pentene products through rectification and separation. Background technique [0002] 1-pentene is an intermediate of fine chemical products with relatively narrow application fields. It is the raw material for producing 1,2-pentanediol through epoxidation, and then producing the insecticide propiconazole. Propiconazole is a green organic pesticide with good development prospects and minimal impact on the environment to replace organophosphorus pesticides; 2-pentene is an important organic chemical raw material, which can be used to produce 2-pentanol and A raw material for 3-pentanol and a polymerization inhibitor. ...

AI Technical Summary

Problems solved by technology

Because the carbon five components contained in raffinate carbon five are more and the boiling points of each component are very close, so although the mode of precision rectification is adopted to produce 1-pentene and 2-pentene, the purity of the obtained product is relatively low. Unable to obtain 1-pentene and 2-pentene products with a content above 98.5%