Etherified C4 superimposition esterification cogeneration method of isooctane and sec-butyl acetate

Abstract

The invention discloses an etherified C4 superimposition esterification cogeneration method of isooctane and sec-butyl acetate. The etherified C4 superimposition esterification cogeneration method of the isooctane and the sec-butyl acetate comprises the following steps: (1), passing an etherified C4 raw material through a reactor filled with a solid acidic catalyst, performing superimposition reaction under reaction conditions that the reaction temperature is 60-90 DEG C and the pressure is 0.8-1.6Mpa, and distilling a superimposition reaction product to obtain the refined C4 raw material on the top of a distillation tower and obtain C8 olefin, with iso-octene as a main part, at the bottom of the distillation tower; and (2) mixing and preheating the refined C4 raw material with acetic acid, passing the mixture through an esterification reactor filled with an esterified heteropoly acid catalyst, and reacting under reaction conditions that the temperature is 70-110 DEG C and the pressure is 1.0-1.4Mpa to obtain the sec-butyl acetate. The superimposition reaction is high in selectivity; the procurement index of the C4 raw material of the sec-butyl acetate is lowered; the supply of the raw material is ensured; and the generated C8 olefin can be used as a high-octane gasoline component, thus improving the economic benefit.

Description

technical field [0001] The invention relates to the technical field of production of sec-butyl acetate, in particular to a production technology for the co-production of isooctene and sec-butyl acetate through carbon four-fold esterification after ether. Background technique [0002] With the continuous development of new fields of application of sec-butyl acetate, the consumption of sec-butyl acetate has gradually increased, which has driven the development of sec-butyl acetate industry, and the consumption of carbon four after the raw material MTBE has also increased rapidly. However, due to the short development time of the catalyst, the process is not very mature, and the requirements for the impurity isobutene in the raw material are relatively strict (≤0.2wt%). The mass fraction of isobutylene generally exceeds 0.25wt%, which cannot meet the requirements for producing high-quality SBA, resulting in the unguaranteed source of C4 raw materials for sec-butyl acetate. [...

AI Technical Summary

Problems solved by technology

However, when pure heteropolyacids are used as oligomerization catalysts for the separation of isobutene and butene-1, due to the strong acidity of the catalyst, the isomerization loss of butene-1 is serious, which is quite unfavorable for the esterification reaction

[0006] Chinese patents CN85102831A and CN1955145A modify the above catalysts, using Zn 2+ , Fe 3+ Equilibrium metal ions pair H in the catalyst + Substitution is used to prepare an acid salt catalyst, which reduces the loss of butene-1, but the reaction product has a complex composition of C10-C16 components. The patent does not mention how to control the superposition of C16 and above in the superposition process of C4 olefins The production volume of the product, and the boiling point of components above C16 is higher than the gasoline boiling range, so it should be strictly limited as a gasoline additive

[0007] Chinese patent CN101190860 proposes a method for the co-production of MTBE, isooctene and diisobutene through superimposed etherification of C4 olefins, wherein the dimerization of isobutene to isooctene is clarified, and the reaction catalyst and reaction conditions are disclosed, but its It requires high isobutene concentration and low butene-1 concentration in the raw material. The isobutene concentration is 5%-100%, and the weight ratio of isobutene to butene-1 should be higher than 1. It is not suitable for treating trace isobutene in C4 after ether

[0008] In the published documents and patents for the one-step synthesis of sec-butyl acetate from acetic acid-butene, the treatment of isobutene in the C4 raw material is not disclosed, and only the literature describes the partial separation of isobutene during the separation of butane by extractive distillation , but its energy consumption is high and the loss of n-butene is serious

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