Method for preparing BDO or succinic diester with by-product from maleic anhydride

A technology of succinic acid diester and by-product, which is applied in the field of preparing BDO or succinic acid diester, can solve the problems of rising production cost, waste, dark color of fumaric acid, etc. Simple and controllable effects

Inactive Publication Date: 2009-01-14
隆鑫
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, because impurities such as mixed oxidative coupling are difficult to remove by decolorization, the obtained fumaric acid has a darker color, and the scope of use is directly limited; if further esterification is required to obtain dimethyl fumarate, further purificat

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Present embodiment is the method for preparing BDO with the by-product (waste water) that maleic anhydride is produced, and concrete method is as follows:

[0028] Add 900 liters of maleic anhydride wastewater into a 1000 liter reactor, depressurize to 40mmHg, distill and remove water, continuously replenish maleic anhydride wastewater in the process, until the volume of the concentrate after most of the water is evaporated reaches about 300 liters, and the acid concentration exceeds 70 % (according to maleic acid, percent by weight, the same below), continue to heat up to 120 ° C of internal temperature, stop heating when there is no longer gas to steam out, and remove the vacuum;

[0029] Add 650 liters of ethanol and 20 kg of concentrated sulfuric acid to the above-mentioned concentrate, heat and reflux for 8 hours, steam out and recover most of the ethanol, cool down, adjust the pH value to neutral with NaOH solution, continue distillation, and collect fractions at 1...

Embodiment 2

[0032] Present embodiment is the method for preparing diethyl succinate with the by-product (waste water) that maleic anhydride is produced, and concrete method is as follows:

[0033] Add 2,700 liters of maleic anhydride wastewater into a 3,000-liter reactor, reduce the pressure to 40 mmHg, and distill off the water. During the process, the maleic anhydride wastewater is continuously replenished until the volume of the concentrate after most of the water is evaporated reaches about 900 liters, and the acid concentration exceeds 50. % (in terms of maleic acid), add water to 3000 liters, add thiourea 15kg, continue to heat up and reflux for 3 hours, cool, crystallize, centrifuge, and dry the solid for subsequent use;

[0034] Take 250 kg of the above solid, add 650 liters of ethanol, 20 kg of concentrated sulfuric acid, heat and reflux for 8 hours, steam out and recover most of the ethanol, cool, adjust the pH value to neutral with NaOH solution, continue distillation, and colle...

Embodiment 3

[0037] Present embodiment is the method for preparing BDO with the by-product (waste water) that maleic anhydride is produced, and concrete method is as follows:

[0038] Add 2,700 liters of maleic anhydride wastewater into a 3,000-liter reactor, reduce the pressure to 40mmHg, and distill off the water. During the process, the maleic anhydride wastewater is continuously replenished until the volume of the concentrate after most of the water is evaporated reaches about 2,500 liters, and the acid concentration exceeds 5. % (in terms of maleic acid), continue to heat up and reflux for 24 hours, cool, crystallize, centrifuge, and dry the solid for subsequent use;

[0039] Take 25 kg of the above solid, add 65 liters of ethanol, 2 kg of concentrated sulfuric acid, heat and reflux for 8 hours, evaporate and recover most of the ethanol, cool, adjust the pH value to neutral with NaOH solution, continue distillation, and collect the fraction at 190-240 ° C. Distillate contains succinic...

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PUM

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Abstract

The invention discloses a method for using by-products of maleic anhydride to prepare BDO or succinic acid diester, wherein, the by-products comprise at least one of wastewater, waste residues and maleic anhydride residues, a preparation method thereof includes the major steps of esterification, distillation, reduction, etc., thereby obtaining a BDO or succinic acid diester product. The method can fully recycle maleic anhydride, fumaric acid, maleic acid, succinic acid, etc. in the by-products such as wastewater, waste residues and maleic anhydride residues in the production process of maleic anhydride, thereby obtaining products such as chemical intermediate BDO or succinic acid diester with great market demands, and maximally reducing the discharge of wastes; and the preparation method has advantages of simple and controllable technical process and rather low cost.

Description

technical field [0001] The invention belongs to the technical field of waste water and residue treatment of chemical synthesis, and in particular relates to a method for preparing BDO or succinic acid diester from by-products produced by maleic anhydride. Background technique [0002] The production methods of maleic anhydride mainly include n-butane oxidation, benzene oxidation and C4 olefin oxidation. In the process of production, purification, equipment cleaning, etc., some acidic by-products will be produced. These acidic by-products are called wastewater after being dissolved in water, mainly containing succinic acid, butyric acid, acetic acid, maleic acid, fumaric acid and partially oxidized Coupling products, etc.; the solid crystallized from long-term (usually three to several years) stored wastewater is called waste residue, which mainly contains fumaric acid, and also contains a small amount of maleic acid, succinic acid and high-temperature oxidation, Cross-linki...

Claims

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Application Information

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IPC IPC(8): C07C31/20C07C29/74C07C69/40C07C67/48
Inventor 曾德超
Owner 隆鑫
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