SU787364A1 - Method of purifying steam-air mixture from ammonia - Google Patents

Description

one

The invention relates to methods for cleaning ammonia from mixtures of toxic vapors and gases with air and can be used to remove ammonia from exhaust gases of industrial plants, as well as to protect catalysts poisoned by ammonia used in air purification systems.

A known method for extracting ammonia from gas mixtures is absorbed by silica gel modified with copper ions flj.

However, this method does not give a high degree of purification due to the Mcl layer of the dynamic capacity of the sorbent.

The closest to the proposed technical essence and the achieved result is the method of extracting ammonia from gas mixtures by absorbing it with cation exchanger KU-2 modified by zinc or magnesium ions, which consists in passing an air-vapor mixture through a layer of Sor-25 Eent 10 cm high at an initial ammonia concentration of 10 mg / l 2.

The disadvantage of this method is the low degree of purification of steam-air mixture from ammonia. thirty

The purpose of the invention is to increase the degree of purification of the vapor-air mixture from ammonia.

This goal is achieved by the fact that in the method of absorption of ammonia m6 | Diffuse cationite, KU-23 cation exchanger modified with copper ions and nickel taken in an amount of 1.01, 5 meq / g cationite is used as a sorbent.

The absorption is carried out at a gas flow rate of 1.5-15.5 thousand hours and a height of the layer of sorbent 4-5 cm.

Nickel, and especially copper, are more prone to complexation than zinc or magnesium, and the use of cation exchanger KU-23 with a developed microporous system makes it possible to increase the dynamic capacity of the sorbent.

The introduction of a nickel or copper B modifier in an amount of 1.0-1.5 mEq / g of cation exchanger is determined by the efficiency of ammonia removal of the vapor-air mixture. The introduction of a modifier of less than 1.0 mg-eq / g of katnonite reduces the degree of purification, and the introduction of more than 1.5 mg-eq / g does not significantly increase the degree of purification of the mixture. At a height of the sorbent layer less than 4 cm, breakthrough of the mixture being cleaned is observed, and at a height of more than 5 cm, the consumption of the sorbent increases, while the degree of purification of the mixture from ammonia remains unchanged. Modified; sorbents are obtained by passing a solution of CuC or NiCEj through a KU-23 cation exchanger of modification 30/100, fractions 1-2 mm in H form, until the pH of the initial solution is equalized and the filtrate. The technology of the method is as follows. The sorption process is carried out in a LAR adsorber; 20-23 ° С, specific air-vapor flow rate 1.515, 5 thousand hours, initial concentration of ammonia in the flow 0.03-0.05 mg / l. Example 1 shows the degree of purification of vapor-air flow from ammonia with cation exchanger KU-23 in copper form. The steam-air mixture containing ammonia at a concentration of 0.03-0.05 kg / l is passed through 1.4 g of the sorbent C-KU-23 30/100 at a speed of 15,500 h at 20-23C. At the same time, the vapor-air mixture is almost completely removed from ammonia (Spritz. 0.005 mg / l). As can be seen from the table. 1 ammonia tank is / 50 kg per 1 g of wet sorbent (5.0 wt.%), In terms of 1 g of dry cation exchanger - about 17 wt.%. Example 2 shows the degree of purification of vapor-air flow from ammonia with cation exchanger KU-23 in nickel form. The steam-air mixture containing ammonia at a concentration of 0.03-0.04 mg / l is passed through 1.42 g of sorbent. Ni-KU-23 30/100 with a speed of 15 500 h at 20-23s. At the same time, the vapor-air mixture is almost completely cleaned (Demand 0.005 mg / l). In this case, as. can be seen from the table. 1, the ammonia capacity is 41 mg per 1 g of wet sorbent (4.1 wt.%), Based on 1 g of dry cation exchanger, about 14 wt.%. In tab. 1 shows the ammonia capacity of the sorbents Cu- and Ni-KU-23 30/100. Table 1

Comparison of the effectiveness of the proposed and known cleaning methods

11-13 thousand,

22-23

10 10 11-13 thousand, 22-23

As can be seen from the table. 2, the proposed method of vapor-air mixture purification using modified sorbents makes it possible to obtain a more complete purification of the vapor-air mixture from ammonia than the known

vapor flow from ammonia is given in table. 2

table 2

13.1

7.7 4.8 2.8

way to. Even with a layer length of two times smaller and larger space velocity of the vapor-air flow, the strongly acidic cation exchanger KU-23 used by nickel ions used in the air flow shows a significantly greater activity.

; absorption of ammonia vapors compared with the activity of Md-KU-2 and slightly higher compared with the activity of 2p-KU-2. The cation exchanger KU-23 modified by copper ions under the same conditions shows a significantly higher degree of ammonia extraction from the vapor-air flow both in comparison with Md and 2n-KU-2.

Claims (2)

1. A method for purifying an air-vapor mixture from ammonia by absorbing it with a modified cation exchange resin, in order to increase the degree of purification, As a sorbent, KU-23g cation exchanger modified with copper and nickel ions was used in the amount of 1.0-1.5 mEq / g of cation exchanger. 2. Method up to claim 1, characterized in that the absorption is carried out at a gas flow rate of 1.515, 5 thousand hours and a height of the sorbent layer of 4-5 cm. HCTOVHHKH information taken into account during the examination o 1. Authors certificate of the USSR 574890, cl. From 01 to 1/12, published. 10.06.77. 2. Authors certificate of the USSR 222340, cl. From 01 to 1/12, published. 07/22/68 (prototype).