SU947043A1 - Method for preparing gas absorbing composition - Google Patents

Description

(5) METHOD OF OBTAINING A GAS AND ABSORBENT MASS

This invention relates to a technique for the chemical treatment of bentonites to absorb gases. A known method for producing the getter mass, consisting in precipitating the hydroxides of iron, copper and aluminum separately from their soluble salts (nitrates) using a solution of caustic soda. The resulting hydroxides are washed, dried and calcined at 650 ° C; then crushed and mixed in the following molar ratios: 1) CuO -, 2). Cuo - Za2.0 ,; H) CuO - AVGO ,, 2Re2 Oz; A) Cuo - -. , Of these four species, the third is considered the best adsorbent, i.e. CuO-A 2.0 2Re2, Oz., The gray intensity of which is about 520 mg / g lj. A significant disadvantage of the method of obtaining this getter is the high cost and complexity, and absorption of sulfur dioxide is limited, it goes only with ZOO-BOO C. The closest to the technical essence and the achieved result to the proposed method is the production of getter mass by treating bentonite with mineral acids, precipitating iron and aluminum hydroxides, washing and heat treatment 2. The method is characterized by insufficiently high sulfur content and mechanical strength of the mass. The purpose of the invention is to increase the sulfur capacity and mechanical strength of the getter mass. This goal is achieved by the method of obtaining the gas absorption material, including the treatment of bentonite with a chemical reagent and heat treatment, as a chemical reagent is used a solution of nitrates or hydroxides of iron and copper with a mass ratio of FeyO and CuO in the solution equal to 1.8-3.4: 1, and the ratio of bentonite to the solution, equal to 1: 0, and the heat treatment is carried out at a temperature of 300-450C. Example 1.BO, 8 l of distilled water dissolve 0.658 kg of iron nitrate and 0.228 kg of copper nitrate. Take 1 kg of air-dry finely ground bentonite, for example, askan gel containing in its composition. weight.: . 62.05; AC O 20.26, FenO 2.95; MDO, 3.98; Cao b, 23; TttT 0.36; + Cor 4.30 and the rest - other impurities. A solution of iron and copper nitrate is added to it and stirred for 5-10 minutes, heated at 300-450 ° C to obtain a finished solid product, which takes about 2 hours. Then the finished solid product is crushed into pieces. Example 2. 1.5 liters of iron nitrate and 0 kg of copper nitrate are dissolved in distilled water of B1.5 l. Take 1 kg of air-dry finely ground bentonite, for example, Ascangel of the indicated composition, a solution of iron and copper nitrate is added to it and thoroughly mixed for 5-10 minutes, heated at 300-450 ° until a ready-made solid is obtained, which requires about 2h Then the finished product is crushed into pieces. Example 3BO, 8 liters of distilled water dissolved 0.337 kg of iron nitrate and 0.152 kg of copper nitrate. Take 1 kg of air-dry finely ground bentonite, for example, Ascangel of the specified composition, a solution of iron and copper nitrate is added to it and thoroughly stirred for a minute, heated at 300-450 until the finished solid product is obtained, which takes about 2 hours. the finished product is crushed into pieces.

EXAMPLE 4. In 1 KG of air-dry finely ground bentonite, for example, Ascangel, 0.174 kg of iron hydroxide and 0.092 kg of copper hydroxide are added and mixed thoroughly for a minute, heated at 300-450 C to obtain the finished solid product, which takes about 2 hours. Then the finished solid product is crushed into pieces.

Thus, sample 1 is the best getter mass.

From tab. 1 also shows that the sulfur-absorption capacity of the gas absorption material obtained from solutions of nitrates of iron and copper and from hydroxides of iron and copper is almost the same, but it is also clear from the same table that sample 3 is less sulfur-containing than sample Example 5- K1kg of air-dry thin crushed bentonite, for example ascangel, add 0 kg of iron hydroxide and 0.10 kg of copper hydroxide and thoroughly mix for 5-10 minutes, heat at C until the final solid product is obtained, it takes about 2 hours. Then the finished solid product is crushed into pieces, Example 6. To 1 kg of air-dry finely ground bentonite; For example, Ascangel, 0.0b7kg of iron hydroxide and 0.0b1 kg of copper hydroxide are added and thoroughly mixed for 5-10 minutes, heated at 300-450 C to obtain a finished solid product, which takes about 2 hours. Then the finished solid product crushed into pieces. The bentonite treated in this way (Example 1) has the following chemical composition, wt%: SiO 51.20; Ae2.8, 16.85; 3 15.35; MgO 3.15; CaO 0.17; TiOj 0.30; Na, 2.0 + 3.52; CuO 7.05 and the rest - other impurities. The activated gas absorption mass is conditionally AK-Ascangel. In tab. 1 shows the physico-chemical characteristics of the resulting gas absorption mass. As can be seen from the table. 1, the increased mechanical strength and graying capacity is reduced when the ratio of the main oxides FeflOWCuO is 2.1 and the oxides of iron and copper to bentonites 0.23 (sample 1) and 3.40 and oxides of iron and copper to bentonites 0.36 (sample 2) in a wide activation temperature range is 300-450C, but it is more economical to perform activation in the temperature range 300-350 0. Sample 2 is somewhat better in terms of sulfur-holding capacity and physicochemical properties than samples 1 and 3, but it is no longer economical. samples 1 and 2, but compared to the known getter masses, it absorbs more than 50, and. At 1 time, the temperature of the activation mode on the gray-capacity of the gas absorption material of the AK-Asgangel is given in Table 2. As can be seen from Table. 2, the absorption proceeds almost equally in the player temperature range from 300 to 50 ° C. This interval is the optimal activation temperature, but it is more economical to activate in the temperature range of 300–350 ° C. The finished product in the technique can be used at temperature conditions given in table. 3. As can be seen from the table. 3, the sulfur content of the AK-angelgel modified with iron and copper oxides is rather high and practically does not depend on the temperature in the range of 25–250 ° C. The AK askanghel rapidly interacts with hydrogen sulfide and sulfur dioxide. As can be seen from the table. t, the sulfur absorption capacity of the spent absorber is also quite high and practically does not depend on temperature in the range of 25. Thus, it is advisable to replace the AK-Ascangel absorber after application and saturation with sulfuric anhydride with fresh one, and send the spent one to purify gases from hydrogen sulfide and vice versa. Finally, the spent AK AK-angel absorber is replaced with fresh one and the spent one is sent to sulfuric acid plants for firing (production of sulfuric acid or liquid SOj). The burned absorber can again be used to absorb sulfur dioxide and hydrogen sulfide, the sulfur content of which is not less than 150 mg / g. Thus, AK-askangel can be used repeatedly with the use of calcined product. The proposed method allows to obtain getter mass for cleaning gas emissions from hydrogen sulfide and sulfur dioxide, the gray content of which increases by 3 times compared to the prototype.

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Sulfur-holding capacity already used for absorption and SOAK-asngel, mg / g

AK-askangel, already used to absorb H S 502

AK-Asquangel, already used to absorb S02 as claimed in the invention. A method for preparing the getter mass, including treating bentonite with a chemical reagent and heat treatment, which is different

table 2

Table k

300

320

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190 by the fact that, in order to simplify the process, to increase the sulfur-holding capacity and the mechanical strength of the getter mass, a solution of nitrates or iron and copper hydroxides with mass

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the ratio of CuO in solution, 1. Japan patent No. 52-106 / 2,

equal to., s-3 ,, and the ratio of ben-cl. 8 (9), 1977.

tonit and solution equal to 1: 0.67-.

1.25, and the heat treatment is carried out at a temperature of 2. Mosquito B.C. Adsorption-structural temperature SOO-JSO C.5tourism, physico-chemical and catalytic sources of information,. The properties of clays. Minsk, 1970,

taken into account during the examination. 168.

Claims (1)

Claim A method of obtaining a getter mass, comprising treating bentonite with a chemical reagent and heat treatment, characterized in that, in order to simplify the method, increase the sulfur intensity and mechanical strength of the getter mass, a solution of nitrates or iron and copper hydroxides is used as a chemical reagent in bulk 11 947043 u. the ratio Fe ^ O ^ n CuO in the solution equal to 1-, 8-3.4: 1, and the ratio of bentonite and solution equal to 1: 0.67 “1.25, and heat treatment is carried out at a temperature of 300-450 ° C. 5