CN1156717A

CN1156717A - Process for producing n-butyl acetate

Info

Publication number: CN1156717A
Application number: CN 96121259
Authority: CN
Inventors: 曾金龙; 郑荣辉; 郑宗敏
Original assignee: Xiamen University
Current assignee: Xiamen University
Priority date: 1996-11-26
Filing date: 1996-11-26
Publication date: 1997-08-13

Abstract

A process for preparing n-butyl acetate uses acetic acid and n-butanol as raw materials, as well as azeotropic additive able to generate azeotrope with raw materials and product, and includes such steps as gas-solid phase reaction under the action of solid acid to obtain n-butyl acetate, condensing to separate out liquid phase, and cyclic use of un-reacted raw materials, n-butyl acetate and azeotropic additive. Its advantages include high output rate of n-butyl acetate up to 98% and no corrosion and pollution.

Description

A kind of method of producing n-butyl acetate

The present invention relates to a kind of producing and manufacturing technique of carboxylicesters.

N-butyl acetate is a kind of raw material that is widely used in industries such as chemical industry, pharmacy, process hides, spices.At present domestic and international industrial production n-butyl acetate is a catalyzer with mineral acids such as sulfuric acid generally, carries out liquid-phase esterification by acetate and propyl carbinol and produces.But vitriolic oxidation and dewatering cause a series of side reactions, and and there are shortcomings such as etching apparatus, waste liquor contamination environment in the yield that makes n-butyl acetate only about 70%.Therefore adopt solid acid catalyst and novel process thereof to replace traditional processing technology and obtain a large amount of research.Zhao Wenxian etc. (fine chemistry industry, 1994 (6): 55) introduced a kind ofly with the solid acid as catalyst, adopted the novel method of liquid-solid phase reactive mode synthesizing n-butyl acetate, the n-butyl acetate yield is 95% under the top condition; Liao Shijun etc. (fine chemistry industry, 1994 (1): 42) introduced a kind of successive reaction with the fixed bed solid acid catalysis---the gas-solid phase reaction reactive mode production ethyl acetate of distillation method.

It is raw material with acetate and propyl carbinol that purpose of the present invention aims to provide a kind of, add a kind of azeotropic additive that can generate azeotrope with raw material and product, under the solid acid effect, make esterification in gas-solid mutually circulating reactive system, react the processing method of producing n-butyl acetate continuously.

The present invention is a raw material with acetate and propyl carbinol, under a kind of solid acid catalyst effect, carry out gas-solid phase esterification and produce n-butyl acetate, its technical process is as follows: (1) adds a kind of azeotropic additive that can generate azeotrope with raw acetic acid, propyl carbinol and product butylacetate in the reaction raw materials of acetate and propyl carbinol; (2) mixture of heating raw and azeotropic additive, and keep it all the time at boiling state, make the ascension of azeotropic gas, by beds, carry out esterification; (3) leave the reaction product of beds and unreacting material and azeotropic additive and pass through condenser condenses, be collected in the reflux water-dividing device, the liquid phase oil water stratification, water is in lower floor, regularly discharge, unreacting material, the positive butyl ester of product and azeotropic additive flow back to the material still again by conduit and recycle on the upper strata.Said catalyzer is a kind of Ti that is carried on the molecular sieve, Zr, and Zn, the mixed oxide of Al, said molecular sieve can be selected from 3A, 4A, 5A type molecular sieve; Said azeotropic additive is a kind of benzene that is selected from, toluene, the solvent of hexanaphthene, particularly benzene; Said azeotropic additive addition is propyl carbinol and acetate mixeding liquid volume 0.02～0.05 times; The reaction bed temperature is 120～170 ℃, is preferably 130～140 ℃; Alcohol: acid (mol ratio) is 1.1～2.0, is preferably 1.1～1.2.The yield of n-butyl acetate can reach more than 98%.

The present invention adopts the solid acid as catalyst, and utilize the insoluble characteristics of component distillation principle and water and organic phase, under 120～170 ℃ temperature of reaction, the esterification of acetate and propyl carbinol is carried out in gas-solid mutually circulating reactive system continuously, the water that reaction produces is separated continuously and is discharged, esterification is carried out towards generating the n-butyl acetate direction all the time, selects appropriate reaction conditions, and the yield of n-butyl acetate reaches more than 98%.Compare with traditional sulfuric acid process, do not have problems such as etching apparatus, waste liquor contamination, and equipment is simple, reaction conditions gentleness, easy handling control.

Accompanying drawing is gas-solid mutually circulating reactive system device synoptic diagram among the present invention.

Further specify the present invention by embodiment below.

Embodiment 1:

Technical process of the present invention realizes by gas-solid mutually circulating reactive system.This reactive system is made of material still (1), reactor (2), reflux water-dividing device (3) and (4) four main devices of condenser, and the material still is equipped with heating installation (11); Reactor top is established a thermometer (21) and is stretched into inside and outside of reactor and establish a heating installation (22), bottom and material still junction and establish a porous barrier (23).

20% solid acid catalyst is inserted the catalyst bed of reactor, and injecting the 600mL mol ratio toward the material still is propyl carbinol-acetate mixed solution of 1.1: 1,40mL benzene.Condenser feeds water coolant, temperature of reactor transfers to 130 ℃, regulation and control material still heating corollary apparatus, make reaction mass be in boiling state so that the gas phase azeotrope of required reaction mass to be provided, by the reactor catalyst bed, reaction back gas phase mixture is a liquid flow Huis flow point hydrophone in condenser condenses, be divided into two-layer, lower floor's water timing ga(u)ge amount is discharged, the upper strata contains the organic phase of n-butyl acetate and unreacted material and azeotropic additive and returns the material still along conduit, finish first round circulation, reaction mass carries out 8 hours esterification continuously in gas-solid mutually circulating reactive system, and the yield of n-butyl acetate reaches 98.2%.

Embodiment 2:

On the basis of embodiment 1, carry out scale-up, take solid acid catalyst 9kg, 1.1: 1.0 propyl carbinol-acetate mixed solution 300L, toluene 5L, according to the method for embodiment 1 was carried out acetate and propyl carbinol continuously 6 hours in gas-solid mutually circulating reactive system esterification, the n-butyl acetate yield is 98.6%.

Embodiment 3-6

Carry out according to implementing side 1 method.Adopt hexanaphthene azeotropic additive, change alcohol-sour mol ratio, esterification the results are shown in Table 1.

Table 1 embodiment 3456 propyl carbinols/acetate (mol ratio) 1.1 1.3 1.5 2.0 n-butyl acetate yields (%), 98.2 98.5 98.8 100 n-butyl acetate selectivity (%), 100 100 100 100 embodiment 7-10 carry out according to the method for embodiment 2, and the esterification under the differential responses temperature the results are shown in Table 2.Table 2 embodiment 789 10

Temperature of reaction (℃) 120 120 140 170 n-butyl acetate yields (%), 97.6 98.2 99.0 98.8 n-butyl acetate selectivity (%) 100 100 100 98.6

Claims

1. a method of producing n-butyl acetate is a raw material with acetate and propyl carbinol, and solid acid is a catalyzer, it is characterized in that its technical process is as follows:

(1). in the reaction raw materials of ethanol and propyl carbinol, add a kind of azeotropic additive that can form azeotrope with raw material, product;

(2). the mixture of heating raw and azeotropic additive, and keep it all the time at boiling state, make the ascension of azeotropic gas, by and answer the device beds to carry out esterification;

(3). leave the reaction product of beds and unreacting material and azeotropic additive mixing gas by condenser condenses, be collected in the reflux water-dividing device, the liquid phase oil water stratification, water is in lower floor, regularly discharge, unreacting material, product n-butyl acetate and azeotropic additive flow back to the material still again by conduit and recycle on the upper strata;

Said catalyzer is a kind of Ti, the Zr on the molecular sieve, mixed oxide of Zn, Al of being carried on; The azeotropic additive is the solvent of benzene or toluene or hexanaphthene, and the addition of azeotropic additive is propyl carbinol and acetate mixeding liquid volume 0.02～0.05 times; 120 ℃～170 ℃ of reactor reaction temperature; Propyl carbinol: ethanol (mol ratio) is 1.1～2.0.

2. a kind of method of producing n-butyl acetate as claimed in claim 1 is characterized in that the azeotropic additive is a benzene.

3. a kind of method of producing n-butyl acetate as claimed in claim 1 is characterized in that temperature of reaction is 130～140 ℃.

4. a kind of method of producing n-butyl acetate as claimed in claim 1 is characterized in that propyl carbinol: acetate (mol ratio) is 1.1～1.2.