A kind of purification method of 3-methyl-3-buten-1-ol

Abstract

The invention discloses a method for purifying 3-methyl-3-butene-1-alcohol. The method adopts extractive distillation technology for separation by adding a solvent; the added solvent is a high-boiling aliphatic alkane or contains aliphatic alcohol the aliphatic alkane; the solvent is added from the middle and upper region of the rectifying column, and the raw materials containing 3-methyl-3-butene-1-alcohol and isoamyl alcohol are added from the middle region of the rectifying column; the bottom liquid is passed through a heater Part of the liquid is vaporized, and the obtained gas is returned to the tower from the gas phase inlet at the bottom of the tower; the gas at the top of the tower is completely condensed into liquid by a condenser and sent to the reflux tank at the top of the tower, and then part of the liquid is removed from the top of the tower by a reflux pump. The reflux port is sent into the tower. The rectifying column is operated under reduced pressure, and the top of the column obtains the pure 3-methyl-3-butene-1-alcohol, and the bottom of the column is a mixture of isoamyl alcohol and solvent. The advantage of this method is that the solvent used is relatively stable at high temperature, and obtaining the 3-methyl-3-butene-1-alcohol product from the top of the column is beneficial to avoid the self-polymerization loss of the product.

Description

[0001] field of invention [0002] The invention belongs to the field of separation of fine chemical water reducer intermediates, and relates to a method for separating and purifying enol from a mixture of enol and saturated alcohol by adding a solvent and extracting and rectifying. Background technique [0003] 3-Methyl-3-buten-1-ol is a water reducer intermediate, which can further synthesize isopentenol (3-methyl-2-butene-1- alcohol). During hydroisomerization, in addition to mainly obtaining prenol, part of 3-methyl-3-buten-1-ol will be converted into isoamyl alcohol. In order to obtain a higher yield of isopentenol, it is necessary to separate 3-methyl-3-buten-1-ol from isopentenol in production. Since the boiling points of 3-methyl-3-buten-1-ol and isoamyl alcohol are very close, it is difficult to achieve the ideal separation effect by conventional separation means, and an effective separation method needs to be developed. [0004] The traditional method for separati...

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Problems solved by technology

Since olefins enter the bottom of the rectification tower with the solvent, and the temperature at the bottom of the tower is often high, it is easy to cause problems such as yield drop and equipment blockage for unsaturated hydrocarbons that are easy to self-polymerize. When nitrogen-containing or sulfur-containing solvents are used There are also unfavorable factors such as solvent pyrolysis

[0005] For the separation problem containing polyolefins, a suitable alternative is to choose a solvent with a strong interaction with saturated bonds, so that polyolefins become volatile components and enter the top of the column, but such solvents are generally difficult to choose

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