RU2529233C1 - Method of producing modified activated carbon - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: modification process includes washing with distilled water, heating to 200°C in an air atmosphere for 2 hours and treating with hydrochloric acid solution with concentration of 0.1 mol/dm³.

EFFECT: high dimethylamine sorption capacity of the carbon and increasing dimethylamine extraction by 35% on average.

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Description

The invention relates to the field of adsorption wastewater treatment from organic compounds and can be used for purification of domestic, process and surface wastewater production of dimethylamine.

A known method for producing modified activated carbon (MAU), which includes its treatment with a low-concentrated effluent from the production of ε-caprolactam containing up to 0.5 g / dm ³ caprolactam and ammonium sulfate up to 0.2 g / dm ³ , with the ratio of the mass of coal (g) to the volume of wastewater (cm ³ ) - 1:10 for 24 hours, further drying and heating of coal at a temperature of 250 ° C in air for 4 hours [1].

The disadvantage of this method of modification is the significant consumption of reagents, heat and electricity.

The closest is a method of producing MAU, including impregnation of coal with water or a solution of hydrochloric acid with a concentration of 1-4 wt.% With a ratio of the total pore volume of coal and water or acid 1.0- (0.7-1.0), and then processing coal 9-15% solution of thermosetting resin in furfural at a weight ratio of coal and solution of 1.0- (0.35-0.68), keeping to flowability and heat treatment with inert gas with a temperature rise rate of 450-900 ° C / hour to 700 -900 ° C, followed by exposure at this temperature for 0.2-0.5 hours [2].

The disadvantage of this method is the high cost of the modifying agent, the duration and complexity of the sorbent preparation process.

The objective of the present invention is to increase the sorption capacity of active carbons for dimethylamine, reduce the consumption of electricity, reagents and the exclusion of toxic waste.

The problem is achieved by preliminary washing with distilled water and heating industrial activated carbon at a temperature of 200 ° C for 2 hours and further processing with a solution of hydrochloric acid, with a ratio of coal mass (g): volume of hydrochloric acid solution (cm ³ ) - 1: 100.

As a comparison, used industrial activated carbon brand AG-5.

Example 1

The ACs were pre-washed with distilled water, dried and warmed up at 200 ° C in air for 4 hours, then treated with a solution of hydrochloric acid with a molar concentration of 0.1 mol / dm ³ , the ratio being the mass of coal (g): the volume of hydrochloric acid solution ( cm ³ ) was 1:50; 1: 100; 1: 200. Then, on modified samples, adsorption was carried out under static conditions from aqueous solutions of dimethylamine with a concentration of 0.25 mol / dm ³ . The data obtained are presented in table 1.

Table 1 The influence of the ratio of the mass of coal (g): the volume of a solution of hydrochloric acid (cm ³ ) during the modification of AC on the adsorption from solutions of dimethylamine No. p / p AU: reagent ratio The increase in the sorption capacity of AC,% one 1:50 15.3 2 1: 100 35.0 3 1: 200 35.6

Example 2

ACs were washed with distilled water and warmed up in air at a temperature of 100 ° C, 200 ° C, 500 ° C for 2 hours and treated with a solution of hydrochloric acid with a molar concentration of 0.1 mol / dm ³ with a ratio of coal weight (g): volume of hydrochloric acid solution (cm ³ ) - 1: 100. Then, on modified samples, adsorption was performed under static conditions from aqueous solutions of dimethylamine with a concentration of 0.25 mol / dm ³ . The data obtained are presented in table 2.

table 2 The effect of temperature in the process of AC modification on adsorption from dimethylamine solutions No. p / p Temperature ° C The increase in the sorption capacity of AC,% one one hundred 11.3 2 200 35.0 3 500 coal burns out to a large extent.

Example 3

The AC was dried, washed with distilled water and warmed up in air at a temperature of 200 ° C for 1, 2, and 4 hours, then it was treated with a solution of hydrochloric acid at a ratio of coal mass (g): volume of hydrochloric acid solution (cm) - 1:10. Then, on modified samples, adsorption was performed under static conditions from aqueous solutions of dimethylamine with a concentration of 0.25 mol / dm ³ . The data obtained are presented in table 3.

Table 3 The influence of heating time in the process of AC modification on adsorption from dimethylamine solutions No. p / p Warm-up time, h Increase in sorption 1 capacity of AC,% one one 25.7 2 2 35.0 3 four 35.3

As a result of the studies, the following modification conditions were selected: washing with distilled water and heating the coal at 200 ° C in air for 2 hours, then treating the activated carbon with a solution of hydrochloric acid with a molar concentration of 0.1 mol / dm, with the ratio of the mass of coal ( g): the volume of a solution of hydrochloric acid (cm ³ ) - 1: 100.

Extraction of dimethylamine by the obtained sorbents increases on average by 35%.

Literature

1. Patent No. 2370439, Russia IPC ⁷ B01J 20/20, C01B 31/08, publ. 10/20/2009.

2. Patent No. 2175885, Russia, MPK ⁷ B01J 20/20, C01B 31/08, publ. 2001.11.20.

Claims (1)

A method for producing modified activated carbon by treatment with a chemical reagent solution, characterized in that the activated carbon is washed with distilled water and heated at 200 ° C in air for 2 hours, then the activated carbon is treated with a solution of hydrochloric acid with a molar concentration of 0.1 mol / dm ³ , with a ratio of the mass of coal in grams to the volume of a solution of hydrochloric acid in cm ³ equal to 1: 100.