CN112574156A - Back extraction purification method for crude product after ethyl maltol sublimation - Google Patents

Abstract

The invention relates to a back extraction purification method of a sublimed crude product of ethyl maltol, which comprises the following steps: (1) adding ethyl maltol into the material dissolving kettle, and then adding pure water, wherein the mass ratio of the ethyl maltol to the water is 1:6, after the feeding is finished, starting steam to heat to 80 +/-5 ℃ for material dissolving; (2) and (3) after the material dissolving is finished, transferring the material in the material dissolving kettle to a layering tank, standing for 10min, layering, separating out impurities on the lower layer, putting the water solution layer on the upper layer into a freezing kettle, cooling to 10-15 ℃, centrifuging by using a centrifuge to obtain ethyl maltol crystals after impurity removal, returning the centrifuged mother liquor to the step (1) for material dissolving and applying, and discharging the mother liquor out of the system when the impurity content in the mother liquor exceeds the index. The method can efficiently remove the irritant impurities in the crude product after the ethyl maltol is sublimated.

Description

Back extraction purification method for crude product after ethyl maltol sublimation

Technical Field

The invention relates to a back extraction purification method of a sublimed crude product of ethyl maltol.

Background

In the production reaction process of ethyl maltol, a large amount of byproducts are generated, wherein part of impurities with pungent odor and close to the boiling point of ethyl maltol are evaporated out along with the ethyl maltol in a sublimation purification section, and are very easy to dissolve mutually and difficult to separate, so that the quality of the ethyl maltol product is difficult to improve.

Disclosure of Invention

The invention aims to solve the technical problem of providing a back extraction purification method for the sublimed crude product of ethyl maltol, which can efficiently remove irritant impurities in the sublimed crude product of ethyl maltol.

In order to solve the technical problem, the invention provides a back extraction purification method of a sublimed crude product of ethyl maltol, which comprises the following steps:

(1) adding ethyl maltol into the material dissolving kettle, and then adding pure water, wherein the mass ratio of the ethyl maltol to the water is 1:6, after the feeding is finished, starting steam to heat to 80 +/-5 ℃ for material dissolving;

(2) and (3) after the material dissolving is finished, transferring the material in the material dissolving kettle to a layering tank, standing for 10min, layering, separating out impurities on the lower layer, putting the water solution layer on the upper layer into a freezing kettle, cooling to 10-15 ℃, centrifuging by using a centrifuge to obtain ethyl maltol crystals after impurity removal, returning the centrifuged mother liquor to the step (1) for material dissolving and applying, and discharging the mother liquor out of the system when the impurity content in the mother liquor exceeds the index.

For the sake of simplicity of explanation, the method for purifying the sublimed ethyl maltol by back-extraction of the crude product is simply referred to as the present method.

The method has the advantages that: 1. the characteristic that water and irritant impurities are immiscible is utilized, and water is utilized for back extraction, so that a large amount of impurities can be efficiently removed; 2. in order to increase the solubility of ethyl maltol in water, a heating mode is adopted, so that the using amount of water is greatly reduced, and the method can realize that the ethyl maltol: water = minimum usage of 1: 6. 3. The ethyl maltol aqueous solution obtained after layering contains less water-soluble impurities, so that repeated application can be realized, and the difficulty in mother liquor wastewater treatment is reduced.

Drawings

FIG. 1 is a flow chart of the present invention.

Detailed Description

The first embodiment is as follows:

referring to fig. 1, a method for back extraction and purification of a sublimed crude product of ethyl maltol comprises the following steps:

(1) adding ethyl maltol into the dissolving kettle 1, and then adding pure water, wherein the mass ratio of the ethyl maltol to the water is 1:6, after the feeding is finished, starting steam to heat to 75 ℃ for material dissolution;

(2) after the material dissolving is finished, transferring the material in the material dissolving kettle 1 to a layering tank 2, standing for 10min, layering, separating impurities on the lower layer, putting the water solution layer on the upper layer into a freezing kettle 3, cooling to 10 ℃, centrifuging by using a centrifuge 4 to obtain ethyl maltol crystals after impurity removal, returning the centrifuged mother liquor to the step (1) for material dissolving and applying, and discharging the mother liquor after the impurity content in the mother liquor exceeds the index.

The first embodiment is as follows:

referring to fig. 1, a method for back extraction and purification of a sublimed crude product of ethyl maltol comprises the following steps:

(1) adding ethyl maltol into the dissolving kettle 1, and then adding pure water, wherein the mass ratio of the ethyl maltol to the water is 1:6, after the feeding is finished, starting steam to heat to 80 ℃ for material dissolution;

(2) after the material dissolving is finished, transferring the material in the material dissolving kettle 1 to a layering tank 2, standing for 10min, layering, separating impurities on the lower layer, putting the upper layer aqueous solution layer into a freezing kettle 3, cooling to 12.5 ℃, then centrifuging by using a centrifuge 4 to obtain ethyl maltol crystals after impurity removal, returning the centrifuged mother liquor to the step (1) for material dissolving and applying, and discharging the mother liquor after the impurity content in the mother liquor exceeds the index.

The first embodiment is as follows:

referring to fig. 1, a method for back extraction and purification of a sublimed crude product of ethyl maltol comprises the following steps:

(1) adding ethyl maltol into the dissolving kettle 1, and then adding pure water, wherein the mass ratio of the ethyl maltol to the water is 1:6, after the feeding is finished, starting steam to heat to 85 ℃ for material dissolution;

(2) after the material dissolving is finished, transferring the material in the material dissolving kettle 1 to a layering tank 2, standing for 10min, layering, separating impurities on the lower layer, putting the water solution layer on the upper layer into a freezing kettle 3, cooling to 15 ℃, centrifuging by using a centrifuge 4 to obtain ethyl maltol crystals after impurity removal, returning the centrifuged mother liquor to the step (1) for material dissolving and applying, and discharging the mother liquor after the impurity content in the mother liquor exceeds the index.

In the above embodiment:

the material dissolving kettle is an enamel material dissolving kettle with a jacket and stirring;

the layering tank adopts an enamel layering tank (a circular end socket at the upper part and a conical bottom part);

the freezing kettle adopts an enamel freezing kettle with a jacket and a stirrer.

Claims (1)

1. The method for back extraction and purification of the sublimed crude product of ethyl maltol is characterized by comprising the following steps of:

(1) adding ethyl maltol into the material dissolving kettle, and then adding pure water, wherein the mass ratio of the ethyl maltol to the water is 1:6, after the feeding is finished, starting steam to heat to 80 +/-5 ℃ for material dissolving;

(2) and (3) after the material dissolving is finished, transferring the material in the material dissolving kettle to a layering tank, standing for 10min, layering, separating out impurities on the lower layer, putting the water solution layer on the upper layer into a freezing kettle, cooling to 10-15 ℃, centrifuging by using a centrifuge to obtain ethyl maltol crystals after impurity removal, returning the centrifuged mother liquor to the step (1) for material dissolving and applying, and discharging the mother liquor out of the system when the impurity content in the mother liquor exceeds the index.

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