RU2502679C1 - Method of purifying water solutions from pyridine - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be applied for purification of technological sewages of chemical industry enterprises. Method of purifying water solutions from pyridine by adsorption by activated coal includes processing of activated coal with ammonium chloride with concentration 5 mg/dm³ for 3 hours. Ratio of activated coal weight to volume of ammonium chloride constitutes 1:100. Pyridine adsorption from its water solution is carried out in static conditions.

EFFECT: invention makes it possible to increase efficiency and economy of purification process.

3 tbl, 15 ex

Description

The invention relates to the field of adsorption technology and can be used for purification of technological effluents of chemical enterprises.

There is a known (RU, patent No. 2240863, IPC B01J 20/20, СВВ 31/08, publ. 11/27/2004) method for purification of pyridine, which consists in the fact that the process of extracting pyridine is carried out on activated carbons (AC), treated sequentially with hydrogen peroxide with a concentration of 36% (ratio of coal and hydrogen peroxide 1: 1.3) for 2.5 hours and 10% (ratio of coal and hydrogen peroxide 1: 3) for 1.5 hours, followed by drying in air.

The disadvantage of this method is the difficulty of obtaining active carbons: the need to use aggressive chemicals with a high concentration, the treatment of AC in two stages and the duration of the process of obtaining AC.

The closest analogue (RU, patent No. 2367598 IPC СВВ 31/16, B01J 20/20; publ. 09/20/2009) is a method for purification of pyridine, which consists in the fact that pyridine is extracted at AC treated with ozone in a thermostated reactor with a constant mixing with a continuous supply of ozone-oxygen mixture for 3 hours.

The disadvantage of this method is the difficulty of obtaining active carbons: the complexity, sophisticated equipment and the use of expensive reagents to obtain AC.

An object of the invention is to increase the efficiency and effectiveness of the process of cleaning aqueous solutions of pyridine due to the use of AU obtained in a cheap and safe way.

The task is achieved by cleaning aqueous solutions of pyridine on AC treated with ammonium chloride with a concentration of 5-10 mg / dm ³ at a weight ratio of AC in grams to the volume of a solution of ammonium chloride in cm ³ 1: 100 for 3 h, at a temperature of 25 ± 2 ° FROM.

At the same time, the adsorption capacity for pyridine increases, which is due to the ability of ammonium chloride to destroy the hydration shell of pyridine and create secondary adsorption centers for additional adsorption of pyridine on the surface of AC.

A portion of activated carbon was poured with a solution of ammonium chloride with a concentration of 0.05-50 mg / dm ³ with a ratio of the mass of coal (g) and the volume of a solution of ammonium chloride (cm ³ ) 1: 50-150, processed for 2-6 hours. Then, on the obtained AC, pyridine was adsorbed from its aqueous solution under static conditions.

Example 1

AC was treated with a solution of ammonium chloride with a concentration of 0.05; mg / dm ³ for 3 hours, with a ratio of the mass of coal (g) to the volume of a solution of ammonium chloride (cm ³ ) 1: 100. On the obtained AC, pyridine was adsorbed from its aqueous solution under static conditions.

Example 2, 3, 4, 5, 6, 7.

AC was treated in the described way with a solution of ammonium chloride with a concentration of, respectively, 0.1; 0.5; 2.5; 5; 10; 50 mg / dm ³ . On the obtained AC, pyridine was adsorbed from its aqueous solution under static conditions. The results are presented in table 1.

Table 1 No. p / p the concentration of NH ₄ Cl, mg / DM ³ increase in the sorption capacity of AC,%

one 0.05 42 2 0.1 53 3 0.5 59 four 2,5 66 5 5 80 6 10 79 7 fifty 79

Example 8

AC was treated with a solution of ammonium chloride with a concentration of 5 mg / dm ³ for 3 hours, with a ratio of coal mass (g): volume of a solution of ammonium chloride (cm ³ ) 1:50. On the obtained AC, pyridine was adsorbed from its aqueous solution under static conditions.

Example 9, 10.

AC was treated in the described manner with the ratio of the mass of coal (g): the volume of a solution of ammonium chloride (cm ³ ), respectively, 1: 100 and 1: 150. On the obtained AC, pyridine was adsorbed from its aqueous solution under static conditions. The results are presented in table 2.

table 2 No. p / p AC ratio: NH ₄ Cl aqueous solution increase in the sorption capacity of AC,% one 1:50 fifty 2 1: 100 80 3 1: 150 84

Example 11

AC was treated with a solution of ammonium chloride with a concentration of 5 mg / dm ³ , with a ratio of coal mass (g): volume of a solution of ammonium chloride (cm ³ ) 1: 100 for 2 hours. On the obtained AC, pyridine was adsorbed from its aqueous solution under static conditions.

Example 12, 13, 14, 15.

ACs were treated in the described manner for 3, 4, 5, 6 hours, respectively. On the obtained AC, pyridine was adsorbed from its aqueous solution under static conditions. The results are presented in table 3.

Table 3 No. p / p the duration of the process, h increase in the sorption capacity of AC,% one 2 66 2 3 80 3 four 81 four 5 82 5 6 83

As a result of the studies, the following conditions for obtaining AC were selected: treatment of industrial active carbons with a solution of ammonium chloride with a concentration of 5 mg / dm ³ for 3 hours with a ratio of AC mass in grams to the volume of NH ₄ Cl in cm ³ 1: 100.

The process at the AC treated with ammonium chloride in this way increases the sorption capacity of activated carbons in relation to pyridine, eliminates the consumption of expensive reagents, electricity and the formation of secondary waste.

Claims (1)

The method of purification of aqueous solutions of pyridine by adsorption with activated carbon treated with chemical reagents, characterized in that as a chemical reagent for treating activated carbon, ammonium chloride with a concentration of 5 mg / dm ^{3 is used} , while the ratio of the mass of active carbon to the volume of the solution of ammonium chloride is 1 : 100, the treatment is carried out for 3 hours, and the adsorption of pyridine from its aqueous solution is carried out under static conditions.