Preparation method and system of sec-butyl alcohol

Abstract

The invention provides a preparation method of sec-butyl alcohol. The method includes the steps of: feeding a mixture obtained after the hydrolysis reaction into a sec-butyl alcohol azeotropic distillation tower for separation; withdrawing a mixed material containing sec-butyl alcohol, sec-butyl acetate and water from the side line of the upper part of the sec-butyl alcohol azeotropic distillationtower, feeding the mixed material into a multi-stage extraction tower, adding an extracting agent chilled water to obtain a sec-butyl alcohol-containing water phase at the bottom of the tower, and withdrawing the water phase at the bottom of the tower; feeding the mixture into a liquid separation tank to obtain a sec-butyl alcohol oil phase at the upper layer of the liquid separation tank; and feeding the sec-butyl alcohol oil phase obtained at the upper layer of the liquid separation tank into a sec-butyl alcohol refining tower for refining, and adding entrainer water to obtain the high-purity product sec-butyl alcohol at the bottom of the tower. According to the method, sec-butyl acetate and sec-butyl alcohol are effectively separated, the yield of the sec-butyl alcohol obtained after separation reaches 99.5% or above, and the one-way yield of the sec-butyl alcohol is greatly increased and is increased to 85% or above from 50%.

Description

technical field [0001] The invention relates to a method and system for preparing sec-butanol, in particular to a method and system for preparing sec-butanol by hydrolyzing 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 indir...

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

Although the separation step is relatively simple in this method, because sec-butyl acetate, sec-butanol and water can form a ternary azeotrope, and the content of sec-butyl acetate contained in the material coming from the reaction system is relatively high, resulting in deacidification The content of sec-butyl acetate in the oil phase after separation of the mixture from the top of the tower is relatively high. After entering the refining tower, sec-butyl acetate, sec-butanol and water azeotrope cause a large amount of sec-butanol to evaporate from the top of the tower, thereby Cause the 2-butanol that obtains at the bottom of the tower to be less, 2-butanol output is lower, simultaneously, a large amount of 2-butanol can not be separated effectively, enter reaction system or deacidification tower and carry out recycling and cause the circulation volume of whole 2-butanol plant to be relatively low. Large, thereby greatly increasing energy consumption, how to effectively separate sec-butyl acetate and sec-butanol without increasing energy consumption of the device and without introducing other impurities is the current method of using sec-butyl acetate hydrolysis A technical problem to be solved in the preparation of sec-butanol

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