Method for preparing sec-butyl alcohol

Abstract

The invention provides a method for preparing sec-butyl alcohol. The method comprises the steps of (1) mixing sec-butyl acetate and water, then putting the mixture into a hydrolysis reactor, and carrying out hydrolysis reaction so as to obtain a mixture of the sec-butyl alcohol, the water and the sec-butyl acetate; (2) after the reaction is finished, sending the obtained mixture to the lower part of a deacidification tower, and enabling separated acetic acid to fall into the bottom of the tower; (3) sending a mixture of the sec-butyl acetate and the sec-butyl alcohol to a sec-butyl alcohol refining tower, adding an entrainer water, enabling an azeotrope of the water, the sec-butyl acetate and part of the sec-butyl alcohol to be evaporated to the top of the tower, carrying out condensation and then enabling a product to be recycled back to a reaction system so as to enable most sec-butyl alcohol to fall into the bottom of the tower, and collecting the sec-butyl alcohol from the bottom of the tower to obtain a product sec-butyl alcohol. After the method is used for preparing the sec-butyl alcohol, the single-pass conversion rate of the sec-butyl acetate is 60% or above, the separated sec-butyl alcohol is high in purity, and the purity reaches 99% or higher; furthermore, the purity of the acetic acid obtained at the bottom of the deacidification tower is also higher and reaches 96% or higher; the yield of the sec-butyl alcohol separated by the method is higher and reaches 65% or above. The method is simple in process and operation, and lower in energy consumption.

Description

technical field [0001] The invention relates to a method for preparing sec-butanol, in particular to a method for preparing sec-butanol by hydrolysis of sec-butyl acetate. Background technique [0002] Secondary butanol (SBA), also known as second butanol, methyl ethyl carbinol, other butanol, 2-butanol, is a colorless, transparent, flammable liquid with a wine-like smell. SBA is used as a solvent in industry, co-solvent with methanol, can be used as a component to increase the octane number of gasoline, and can also be used to produce plasticizers, mineral dressing agents, herbicides, sec-butyl esters, etc., but the most important application is The production of methyl ethyl ketone accounts for about 90% of the total consumption. At present, the relatively mature methods in the industry include the indirect hydration method of n-butene and the direct hydration method of n-butene. The traditional process for preparing sec-butanol is sulfuric acid indirect hydration, which...

AI Technical Summary

Problems solved by technology

The disadvantage is that the single-pass conversion rate of n-butene is low, only about 6%, and the requirements for raw materials are relatively strict. If the n-butene content of the C4 raw material used in the direct hydration process is greater than 90%, it may be directly hydrated to SBA, if the B-B grade fraction with lower n-butene content is directly reacted, the project cost will be increased due to its low conversion rate and high circulation rate, so extractive distillation or molecular sieve separation should be carried out first, and pre-purification should be carried out to achieve the maximum reduction. purpose of production cost

In this invention, the process is relatively long, and the obtained methyl acetate product is a crude ester product with a mass fraction of about 82% and low purity. However, in the sec-butanol refining tower, since sec-butanol and sec-butyl acetate can form an azeotrope , the boiling point of the azeotrope is 99.6 ° C, and the boiling point of sec-butanol is 99.5 ° C, so, in this column, sec-butanol and sec-butyl acetate cannot be separated well, and high-purity sec-butanol cannot be obtained basically alcohol

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