RU2333790C1 - Adsorbent for means of sorption technology - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the field of sorption technology and can be used in processes of purification of ammonia and vapour of organic substances in waste industrial vapour-gas mixtures or in filtering means of individual and collective protection of respiratory organs. Adsorbent contains active coal, nickel salts, compounds of alkaline metals in the form of mixture of nickel chloride and oxychloride, chlorides, carbonates and hydroxides of alkaline metals of variable composition, with the following ratio of components, weght %: nickel chlorides and oxychlorides in nickel chloride equivalent 16-26; chlorides, carbonates and hydroxides of alkaline metals in metal equivalent 0.6-3.1, the rest being active coal.

EFFECT: increase of adsorbent sorption capability for vapour of organic substances with preservation of high absorbing capacity of ammonia under conditions of high humidity.

3 cl,1 tbl

Description

The invention relates to the field of sorption technology and can be used in the purification of ammonia and vapors of organic substances in industrial exhaust gas-vapor mixtures or in filtering means for individual and collective respiratory protection.

Known chemisorbent for the absorption of ammonia, obtained by impregnation of activated carbon with a total pore volume of 0.85-1.2 cm ³ / g Nickel chloride solution containing 25-35 wt.% Nickel chloride (US Pat. RF No. 2237513, CL B01J 20/20, C01B 31 / 08, published on 10/10/2004).

The disadvantage of this adsorbent is the low protective properties of organic substances.

Known adsorbent for respiratory protection, containing activated carbon with a total porosity of at least 0.8 cm ³ / g and Nickel chloride, with an additional content of calcium chloride and the following ratio of components, wt.%:

Nickel chloride 5-10 Calcium chloride 10-15 (3.6-5.4 in terms of Ca) Active carbon Rest

(Pat. RF No. 2207903, class B01J 20/20, 20/02, A62B 23/00, published on July 10, 2003).

The disadvantage of this adsorbent is the low absorption capacity of the adsorbent for ammonia vapors.

Closest to the proposed invention in technical essence is an adsorbent for sorption technology, containing activated carbon impregnated with nickel chloride, and optionally alkali metal compounds in the form of lithium bromide, in the following ratio, wt.%:

Nickel chloride 14-22 Lithium bromide 10-16 (0.8-1.3 in terms of Li) Active carbon Rest

(RF patent No. 2139137, class B01J 20/20, C01B 31/16, A62B 23/00, publ. 10/10/1999).

This adsorbent has a high absorption capacity for ammonia vapors, including in high humidity conditions.

Its disadvantage is the insufficiently high sorption capacity for pairs of organic substances.

The technical task of the invention is to increase the sorption capacity of the adsorbent for vapors of organic substances (benzene, cyclohexane, etc.) while maintaining a high absorption capacity of ammonia in high humidity.

The technical problem is achieved by the fact that the adsorbent for sorption technology, containing activated carbon, nickel salts and alkali metal compounds in the form of a mixture of nickel chloride and oxychloride, chlorides, carbonates and alkali metal hydroxides of variable composition, in the following ratio of components, wt.%:

Nickel chlorides and oxychlorides in terms of nickel chloride 16-26 Chlorides, carbonates, alkali metal hydroxides in terms of metal 0.6-3.1 Active carbon Rest

The adsorbent contains activated carbon of chemical activation with the addition of alkali metals with a primary volume of sorption space of micropores of 0, 45-0.70 cm ³ / g

The adsorbent contains its own volume of sorption space of micropores in an amount of 0.30-0.45 cm ³ / g

The difference of the proposed adsorbent is that it:

- contains as active additives a mixture of nickel chloride and oxychloride in an amount of 16-26% in terms of nickel chloride, chlorides, carbonates, alkali metal hydroxides in an amount of 0.6-3.1% in terms of metal;

- contains microporous activated carbon obtained by chemical activation in the presence of alkali metal additives with a primary sorption volume of 0.45-0.70 cm ³ / g;

- has its own volume of sorption space of micropores in an amount of not less than 0.30-0.45 cm ³ / g.

Active carbon in the proposed adsorbent provides the absorption of organic vapor.

Nickel chlorides and oxychlorides provide efficient absorption of ammonia vapors and prevent the formation of insoluble nickel compounds, which can block access to micropores.

Chlorides, carbonates, alkali metal oxides provide hydrophilicity of the inner surface of activated carbon and the effective operation of the adsorbent for ammonia vapors in conditions of high humidity.

The proposed adsorbent is prepared as follows.

Nickel chloride is dissolved in water or a relatively weak solution of hydrochloric acid.

Activated carbon obtained by chemical activation with the addition of alkali metals (in particular potassium carbonate), with a micropore volume of at least 0.45 cm ³ / g, is impregnated either with a solution of nickel chloride in hydrochloric acid or with a mixture of an aqueous solution of nickel chloride and hydrochloric acid with intermediate heat treatment after aging. The ratio of activated carbon by weight in kg and impregnating solution by volume in dm3 is taken 1: (0.5-1.0), respectively. After the end of the impregnation and aging, the active product is subjected to heat treatment at a temperature above 100 degrees Celsius until a constant mass is achieved.

Data on the absorption capacity of the proposed and known adsorbent are shown in the table.

The test conditions for adsorbents in dynamic tubes are as follows:

The height of the adsorbent layer is 3 cm

Specific flow rate - 0.5 l / min · cm ²

Relative flow humidity:

Ammonia vapor at a temperature of 21.5 degrees Celsius - 75.2%

Benzene vapor at a temperature of 22.0 degrees Celsius - 70.2

The initial concentration of ammonia is 2.3 g / m ³

The initial concentration of benzene is 10 g / m ³

Table Adsorbent Chloride, nickel oxychlorides, wt.% In terms of NiCl ₂ Chlorides, carbonates, potassium oxides, wt.% In terms of K Dynamic activity, min, by ammonia Dynamic activity, min, benzene Proposed twenty 1.8 92 35 16 3.1 80 38 fifteen 3.1 74 38 16 3.2 78 33 26 0.6 93 25 27 0.5 81 23 Prototype 20NiCl ₂ 1.0 LiBr 80 16

As can be seen from table 1, the best result is achieved when the adsorbent contains chloride and nickel oxychlorides in an amount of 20 wt.% In terms of NiCl ₂ and chlorides, carbonates, potassium hydroxides in an amount of 1.8 wt.% In terms of K.

A decrease in the content of nickel chlorides and oxychlorides in the adsorbent below 16 wt.% In terms of NiCl ₂ leads to a decrease in the time of the protective action of ammonia.

A decrease in the content of potassium compounds lower than 0.5% in terms of K. leads to a similar result.

An increase in the content of nickel chloride and oxychlorides in the adsorbent above 26 wt.% In terms of NiCl _2, as well as an increase in the content of potassium compounds higher than 3.1% in terms of K, leads to a decrease in the time of the protective effect on benzene.

The proposed adsorbent in its absorption capacity for ammonia in dynamic conditions is not inferior to the prototype and significantly, 1.5-2.3 times greater than the adsorbent prototype in its absorption capacity for benzene.

The proposed adsorbent in dynamic conditions has a high absorption capacity for ammonia at a sufficiently high absorption capacity for vapors of organic substances in high humidity steam-air mixture.

The proposed adsorbent is produced by a simple, reproducible technology using available raw materials.

Tested experimental batches of the proposed adsorbent for equipping filters for respirators and gas masks for labor protection and for the Ministry of Emergencies showed their compliance with the requirements of GOST R 12.4.193-99.

The specifications are currently being drawn up for the proposed adsorbent and it is planned to manufacture pilot and installation batches for equipping gas filters in individual and collective protective equipment.

Claims (3)

1. The adsorbent for sorption technology, containing activated carbon, nickel salts and alkali metal compounds, characterized in that they use alkali metal compounds in the form of a mixture of nickel chloride and oxychloride, chlorides, carbonates and alkali metal hydroxides of variable composition in the following ratio, wt. .%: Nickel chlorides and oxychlorides in in terms of nickel chloride 16-26 Chlorides, Carbonates, Hydroxides alkali metals in terms of metal 0.6-3.1 Active carbon Rest 2. The adsorbent for sorption technology according to claim 1, characterized in that it contains activated carbon of chemical activation with the addition of alkali metals with a primary volume of sorption space of micropores of 0.45-0.70 cm ³ / g 3. The adsorbent for sorption technology according to claim 1, characterized in that it contains its own volume of sorption space of micropores in an amount of 0.30-0.45 cm ³ / g