Process for reclaiming o-chlorobenzoic acid from mother liquor or waste water

A technology for o-chlorobenzoic acid and wastewater, applied in the separation/purification of carboxylic acid compounds, organic chemistry, etc., can solve the problems of waste of resources, increase the load of wastewater treatment, etc., achieve reduction of treatment load, simple recovery method, and good economic benefits Effect

Inactive Publication Date: 2009-09-02
NANJING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] O-chlorobenzoic acid production mother liquor or the production mother liquor of o-chlorobenzoic acid by-product during the production of o-chlorobenzaldehyde con...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] Get o-chlorobenzoic acid synthetic mother liquor 500ml, and o-chlorobenzoic acid concentration is 2800mg / L, and adding sulfuric acid or sodium hydroxide to regulate mother liquor pH is 7-8; 335 type as an example) 10ml column, treated with dilute sulfuric acid and dilute sodium hydroxide solution to form OH type and then adsorbed. The adsorption temperature is 5°C, the flow rate is 6BV / h, the concentration of the adsorbed water is 165mg / l, and the recovery rate is 94.1 %. After adsorption saturation, use 2% sodium hydroxide solution to desorb at a temperature of 35° C. and a flow rate of 2 BV / h to obtain a sodium o-chlorobenzoate solution with a desorption rate of 99.1%.

Embodiment 2

[0013] Get 500ml of o-chlorobenzoic acid synthetic mother liquor, the concentration of o-chlorobenzoic acid is 2800mg / L, add sulfuric acid or sodium hydroxide to adjust mother liquor pH=7; For example) 10ml is packed into a column, treated with dilute potassium hydroxide solution and dilute hydrochloric acid to form C1 type and then adsorbed. The adsorption temperature is 40°C and the flow rate is 2BV / h. After saturated adsorption, use 4% sodium hydroxide solution to desorb at a temperature of 50° C. and a flow rate of 3 BV / h to obtain a sodium o-chlorobenzoate solution with a desorption rate of 98.8%.

Embodiment 3

[0015] Take 500ml of o-chlorobenzoic acid synthesis mother liquor, the concentration of o-chlorobenzoic acid is 2800mg / L, pH=2.2.

[0016] Get highly polar macroporous adsorption resin (the NKA-2 type produced by Tianjin Nankai Chemical Factory as an example, NKA-2 is styrene-diethylbenzene structure) 10ml packing column, pretreatment is as follows: successively with 4% hydrochloric acid, Acetone, 4% sodium hydroxide solution and washed to neutral.

[0017] Adsorption: The adsorption temperature is 25°C, the flow rate is 8BV / h, the concentration of o-chlorobenzoic acid in the adsorbed water is 108mg / L, and the recovery rate is 96.1%. After saturated adsorption, use 4% sodium hydroxide solution to desorb at a temperature of 90° C. and a flow rate of 1 BV / h to obtain a sodium o-chlorobenzoate solution with a desorption rate of 99.6%.

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Abstract

The invention discloses a process for reclaiming o-chlorobenzoic acid from mother liquor or waste water, which comprises that: alkalescent ion exchange resin or macroporous absorbent resin is loaded into an adsorption column; after conventional pretreatment, mother liquor of o-chlorobenzoic acid or waste water containing o-chlorobenzoic acid to be treated flows through the adsorption column, the adsorption temperature is controlled to be between 5 and 40 DEG C and the flow rate is controlled to be between 2 and 16 BV/h, and o-chlorobenzoic acid is exchanged or adsorbed on the resin; and after the resin is adsorbed by the adsorption column to saturation, 2 to 4 percent NaOH solution or KOH solution or an organic solvent of methanol, ethanol, acetone or aether and the like is used for desorption to generate sodium o-chlorobenzoic acid water solution or methanol, ethanol, acetone or aether water solution of o-chlorobenzoic acid, the flow rate is controlled to be between 1 and 3 BV/h and the temperature is controlled to be between 35 and 90 DEG C, and the methanol, ethanol, acetone or aether water solution of o-chlorobenzoic acid is distilled and separated to obtain the o-chlorobenzoic acid and the organic solvent. The reclaiming method is simple, the recovery rate of the o-chlorobenzoic acid reaches 92 to 96 percent, and the method has good economic benefit, reclaims the resources and simultaneously lightens the treatment burden of the waste water.

Description

technical field [0001] The present invention relates to the recovery of o-chlorobenzoic acid, specifically, relate to the method for reclaiming o-chlorobenzoic acid with weakly alkaline or macroporous adsorption resin from mother liquor or waste water. Background technique [0002] O-chlorobenzoic acid production mother liquor or the production mother liquor of o-chlorobenzoic acid by-product during the production of o-chlorobenzaldehyde contains about 0.24% o-chlorobenzoic acid. This kind of production mother liquor is sent to waste water treatment, which wastes resources and increases waste water treatment. load. Contents of the invention [0003] The present invention is the technology that adopts resin recovery o-chlorobenzoic acid, specifically refers to a kind of adopting weakly basic or macroporous adsorption resin to absorb o-chlorobenzoic acid under the condition of 5-40 ℃ and flow velocity 2-16BV / h, and then dilute The lye (represented by sodium hydroxide soluti...

Claims

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Application Information

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IPC IPC(8): C07C63/70C07C51/47
Inventor 赵玉明代允安浩
Owner NANJING UNIV
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