Decolorization and purification technology for sodium dehydroacetate

A technology of sodium dehydroacetate and dehydroacetic acid, which is applied in the field of fine chemicals, can solve problems such as poor operating environment, product loss, and high labor intensity, and achieve high-quality results

Inactive Publication Date: 2016-03-09
NANJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The purpose of the invention is to solve the existing product loss in the sodium dehydroacetate production process, the operating environment is poor, and the problems of labor intensity are high, and a kind of decolorization and refining process of sodium dehydroacetate based on ceramic nanofiltration membrane separation technology is propo

Method used

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  • Decolorization and purification technology for sodium dehydroacetate
  • Decolorization and purification technology for sodium dehydroacetate
  • Decolorization and purification technology for sodium dehydroacetate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032](1) drop into 1000g deionized water and the dehydroacetic acid crude product 1000g of mass fraction about 95% in the reactor, start stirring, adjust the stirring intensity to be 100rpm, and slowly drip the mass fraction is 1250g of aqueous sodium hydroxide solution of 18%, After the sodium hydroxide solution in the metering tank is added dropwise, open the steam jacket, gradually raise the temperature to 90° C., and stir at this temperature for 1 hour. At this time, the measured pH of the solution is 8.1, and the light transmittance is 50%;

[0033] (2) the sodium dehydroacetate synthetic material that last step obtains is transported to ceramic nanofiltration membrane decolorization device (as figure 2 shown), using ZrO with a molecular weight cut-off of 200Da 2 Sheet-type ceramic nanofiltration membrane, the control operating pressure is 1MPa, the system operating temperature is 90°C, the membrane surface flow rate is 3m / s, the pigment impurities in the material are c...

Embodiment 2

[0037] (1) 1200g of deionized water and 1000g of dehydroacetic acid crude product with a mass fraction of about 92.5% are dropped into the reactor, and the stirring is started, and the stirring intensity is adjusted to be 200rpm, and 1050g of aqueous sodium hydroxide solution with a mass fraction of 23% is slowly added dropwise, After the sodium hydroxide solution in the metering tank is added dropwise, open the steam jacket, gradually heat up to 85°C, and stir at this temperature for 1.5h. At this time, the measured pH of the solution is 9.2, and the light transmittance is 41%.

[0038] (2) the sodium dehydroacetate synthetic material that last step obtains is transported to ceramic nanofiltration membrane decolorization device (as Figure 4 shown), using 19-channel Al with a molecular weight cut-off of 400Da 2 o 3 Ceramic nanofiltration membrane, the control operating pressure is 1MPa, the system operating temperature is 85°C, the membrane surface flow rate is 4m / s, the pig...

Embodiment 3

[0042] (1) drop into 2100g deionized water and 1400g of crude product of dehydroacetic acid of mass fraction about 90% in the reactor, start to stir, adjust the stirring intensity to be 300rpm, and slowly add dropwise the mass fraction of 30% sodium hydroxide aqueous solution 1200g, After the sodium hydroxide solution in the metering tank is added dropwise, open the steam jacket, gradually heat up to 80° C., and stir at this temperature for 1 hour. At this time, the pH of the solution is measured to be 9, and the light transmittance is 34%.

[0043] (2) The sodium dehydroacetate synthesis material obtained in the previous step is transported to the ceramic nanofiltration membrane decolorization device, and the molecular weight cut-off is 300Da using 19 channel ZrO 2 -TiO 2 Ceramic nanofiltration membrane, the arrangement of membrane modules is 1 stage and 5 sections, the control operating pressure is 1.5MPa, the system operating temperature is 80°C, the membrane surface flow r...

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Abstract

The invention relates to a decolorization and purification technology for sodium dehydroacetate. The decolorization and purification technology includes the steps that with a dehydroacetic acid crude product as the raw material, synthesis of sodium dehydroacetate is performed; after a reaction is finished, the material enters a ceramic nanofiltration membrane decolorization device in a heat-preserved state, and a permeation side solution enters a crystallization kettle for cooling crystallization; a concentration side solution enters a ceramic nanofiltration membrane elution device, hot deionized water is added to elute a product, and evaporative crystallization is performed; crystals are dehydrated, washed, dried, smashed and packaged to form the product. The purity of the product reaches 99.9%, and the recovery rate of sodium dehydroacetate reaches up to 99% or above in the whole process. By adopting the ceramic nanofiltration membrane decolorization and purification technology, product quality can be obviously improved, operation intensity can be relieved, a field operation environment can be improved, and production cost can be reduced.

Description

technical field [0001] The invention relates to a process for decolorizing and refining sodium dehydroacetate, in particular to a process for decolorizing and refining sodium dehydroacetate based on ceramic nanofiltration membrane separation technology, and belongs to the field of fine chemicals. Background technique [0002] Sodium dehydroacetate is a new type of safe anti-mold, anti-corrosion and fresh-keeping agent for food and feed. It can effectively inhibit the growth of mold and bacteria, help to improve the stability of the product, and greatly extend the storage period of the product. At room temperature, sodium dehydroacetate is a white crystalline powder, and its molecular formula is C 8 h 7 NaO 4 ·H 2 O, with a molecular weight of 208.15, is easily soluble in water, not affected by pH, and has good light resistance and heat resistance, so it is widely used. [0003] The method that sodium dehydroacetate production technology adopts is: (1) the synthesis of d...

Claims

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Application Information

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IPC IPC(8): C07D309/36
CPCC07D309/36
Inventor 范益群唐剑雄邱敏慧闻娟娟邢卫红笪晓薇
Owner NANJING UNIV OF TECH
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