Method and device for preparing sec butanol

Abstract

The present invention provides a method and a device for preparing sec butanol, and the method is as follows: (1) sec-butyl acetate is introduced into a first-stage catalytic distillation column, excessive C1-C3 alcohols are added simultaneously for ester exchange, the sec butanol as a product falls into a tower kettle to collect, and the unreacted C1-C3 alcohols and reaction product acetic acid C1-C3 esters partly are sent into a second-stage catalytic distillation column for further reaction separation; (2) excessive sec-butyl acetate is added into the second-stage catalytic distillation column, the acetic acid C1-C3 esters are distilled off from the top of the column, and then congealed to partly reflux to the top of the second-stage catalytic distillation column and partly use as a product to collect; and (3) the sec butanol obtained by the step (2) and the unreacted sec-butyl acetate are returned to the first-stage catalytic distillation column for further reaction separation. The purity of the sec butanol obtained by the method is high above 99.9%, the purity of the separated acetic acid C1-C3 esters is more than 99%, at the same time, the method has the advantages of simple process and easy operation, compared with the process of butylene hydration for preparing the sec butanol, energy consumption is greatly reduced, and cost is saved.

Description

technical field [0001] The invention relates to a method and device for preparing sec-butanol, in particular to a method and device for preparing sec-butanol through a double catalytic rectification process. 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 sul...

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 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. 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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