RU2452561C2 - Sorbent for atmospheric air cleaning - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to sorption cleaning of air of nitrogen, sulfur oxides and hydrogen sulfide. Sorbent is produced by mixing 100 g of fine Portland cement 500, 100 g of Astrakhan Region boxes with 100 cm³ of 10%-water solution of table salt, and making granules with 0.5 - 5 cm-diameter. Produced mix is hardened and placed in running water unless negative reaction to chloride-ion. After drying, granules are placed in 40%-solution of diethanolamine for 1 h. Then, granules are placed onto sieve to be dried in air flow. Sorbet features the following chemical composition, in wt %: CaO - 40.0, SiO₂ -15.0, NH(CH₂)₄OH₂ - 5.0, H₂O - 5.0.

EFFECT: efficient air cleaning.

2 cl, 2 tbl

Description

The invention relates to sorbents for the purification of atmospheric air from hydrogen sulfide, carbon dioxide and sulfur. The sorbent was obtained by mixing 100 grams of finely ground Portland cement-500, 100 grams of flask and 100 cm ^{3 of a} 10% solution of sodium chloride, granules with a diameter of 0.5-5.0 cm are formed from the resulting mixture, the formed mass is solidified and treated with water until negative reaction to chloride ions, dried at 80-85 ° C, then incubated for 1 hour in a 40% aqueous solution of diethanolamine to its content in the sorbent in the amount of 5% of the mass. and dried in a stream of air at 20-40 ° C until the water content in the sorbent in the amount of 5% of the mass.

The claimed sorbent contains a mixture of flask with Portland cement-500, containing in terms of oxides (wt.%): CaO - 40, SiO ₂ - 35, Al ₂ O ₃ - 15 and additionally diethanolamine - 5 (wt.%) And water - 5 (mass%).

Known sorbent for cleaning atmospheric air with the sorbent S-KP [1] (2336945, 03/06/2007). The sorbent C-KP is expanded clay granules coated with a thin layer of pyrolusite and is intended for purification of atmospheric air from oxides of nitrogen, carbon, sulfur, formaldehyde and butyl mercaptan. Get C-KP by lowering silted, granular and dried clay with pyrolusite, followed by calcination at 1150-1200 ° C.

However, the main disadvantage of this sorbent is the low sorption of acid gases such as hydrogen sulfide, sulfur dioxide and carbon dioxide.

A known method of preparing a sorbent based on activated carbon for the purification of gases from hydrogen sulfide, which can also find application for purification of atmospheric air [2]. The initial activated carbon is impregnated with an aqueous solution of potassium iodide with a concentration of 0.5-3.5 wt.%, In which 0.035-0.075 wt.% Of monoethanolamine (MEA) is additionally added. The amount of water for the preparation of the impregnating solution is taken based on the mass of activated carbon. Sorbent provides high performance air purification process and avoids frequent replacement of the catalyst [2] (RU 2254916, 06.27.2005).

However, the disadvantage of this method, taken as a prototype, is the inability to purify other acid gases in the complex, as well as the low absorption capacity of MEA for hydrogen sulfide.

We propose a new sorbent obtained by mixing finely ground 100 g of Portland cement-500, 100 g of the flask of the Astrakhan region with 100 cm ^{3 of} 10% aqueous solution of sodium chloride and the formation of granules of the required size (from 0.5 to 5 cm in diameter), the formed mass after setting and hardening, they are placed in running water and maintained until the water has a negative reaction to chloride ions, after drying at 80-85 ° C, the granules are placed in a 40% aqueous solution of diethanolamine (DEA) for 1 hour , then the granules are transferred to si then, the excess DEA is removed, and the granules are dried in a stream of air (fan) at 20-40 ° C. The sorbent is designed to purify atmospheric air from acid gases, such as hydrogen sulfide, sulfur dioxide, carbon dioxide. The claimed sorbent contains a mixture of flask with Portland cement-500, containing in terms of oxides (wt.%): CaO - 40, SiO ₂ - 35, Al ₂ O ₃ - 15 and additional diethanolamine - 5 wt.% And water 5 wt.% .

Sorbent Test

Experiments were conducted on the purification of atmospheric air from hydrogen sulfide, carbon dioxide and sulfur dioxide on a sorbent. In order to study air purification in bottles with a capacity of 5 dm, a small vacuum was created using a vacuum pump (residual pressure ~ 0.6 · 10 ⁵ N / m ² ) and gases were passed through a special pipe, which were obtained by the reaction of copper with sulfuric acid (received SO ₂ ), by the reaction of sodium sulfide with sulfuric acid (obtained H ₂ S) or by the reaction of calcium carbonate with hydrochloric acid (received CO ₂ ). Then air was let into the bottle to bring the total pressure to 1.02-10 ⁵ N / m ² and a mixture of air and test gas from the bottle was passed through sorbent granules with a diameter of 2 cm, creating a vacuum at the outlet of this tube.

, где m_исх - содержание H₂S, или SO₂, или CO₂ в воздухе до очистки, мг/м³, m_кон - содержание H₂S, или SO₂, или CO₂ в воздухе после очистки, мг/м³.Table 1 shows the results of experiments on the purification of atmospheric air into which certain toxicants were added. The degree of purification S was calculated by the formula

where m _ref is the content of H ₂ S, or SO ₂ , or CO ₂ in the air before purification, mg / m ³ , m _con is the content of H ₂ S, or SO ₂ , or CO ₂ in the air after purification, mg / m ³ .

Table 1 The results of air purification from various toxicants using a sorbent. Sulfur dioxide (SO ₂ ). MPC _m. - 0.1 mg / m ³ Contact time, s The initial concentration of m _ref , mg / m ³ Cleaning results Found m _con , mg / m ³ S,% 0 twenty twenty 0 5 twenty 0.002 ± 0.0002 99,99 10 twenty 0.002 ± 0.0002 99,99 twenty twenty 0.002 ± 0.0002 99,99 Hydrogen sulfide (H ₂ S). MPC _m. - 0.008 mg / m ³ Contact time, s The initial concentration of m _ref , mg / m ³ Cleaning results Found m _con , mg / m ³ S,% 0 twenty twenty 0 5 twenty 0.001 ± 0.0001 99,99 10 twenty 0.001 ± 0.0001 99,99 twenty twenty 0.008 ± 0.0001 99,99 Carbon dioxide (CO ₂ ) Contact time, s The initial concentration of m _ref , mg / m ³ Cleaning results Found m _con , mg / m ³ S,% 0 twenty twenty 0 5 twenty 0.001 ± 0.0001 99,99 10 twenty 0.002 ± 0.0002 99,99 twenty twenty 0.002 ± 0.0002 99,99

From the results given in table 1, it can be seen that the sorbent can be used for air purification of residential premises, working areas of industrial enterprises and drilling areas. The possibility of purifying atmospheric air from groups of toxicants has been studied. For this, the simultaneous generation of several toxicants was used. The results of air purification from a mixture of hydrogen sulfide, carbon dioxide and sulfur are given in table 2.

table 2 The results of the sorption purification of atmospheric air from a mixture of hydrogen sulfide, carbon dioxide and sulfur Contact time, s The concentration of the aftertreatment substance, mg / m ³ , the air contains a mixture of substances, the concentration of each of which is indicated by numbers Cleaning results Found m _con , mg / m ³ S,% 5,0 SO ₂ - 20.0 0.002 ± 0.0002 99,99 5,0 CO ₂ - 20.0 0.002 ± 0.0002 99,99 5,0 H ₂ S - 10.0 0.001 ± 0.0001 99,99

As can be seen from table 2, the sorption purification of atmospheric air using the proposed sorbent is highly effective and can be recommended everywhere in cases where only chemisorption purification has a noticeable effect.

Information sources

1. Patent 2336945 Russian Federation, IPC B01J 20/06, B01J 20/08, B01J 20/10. Sorbent C-KP for atmospheric air purification [Text] / N.M. Alykov, E.M. Evsina .: applicant and patent holder Astrakhan State University. - No. 2007108441/15; application 03/06/07; publ. 10/27/08, bull. No. 30, 7 pp.

2. Patent 2254916 Russian Federation, IPC B01J 20/30 B01D 52/02. A method of preparing a sorbent for cleaning gases from hydrogen sulfide [Text] / A.A. Moshkin, V.I. Lazarev, A.N. Sobolev, V.I. Geraskin. No. 2004102652/15; application .: 01/30/2004; publ. 06/27/2005, 8 pp.

Claims (2)

1. A method of producing a sorbent for purifying atmospheric air of hydrogen sulfide, carbon dioxide and sulfur dioxide, characterized in that 100 g of finely ground Portland cement-500, 100 g of flask and 100 cm ^{-3 of a} 10% sodium chloride solution are mixed, from the resulting mixture granules with a diameter of 0.5-5.0 cm, the formed mass is subjected to solidification and treatment with water until a negative reaction to chloride ions is dried at 80-85 ° C, then kept for 1 h in a 40% aqueous solution of diethanolamine to its content in the sorbent in an amount of 5 ma .% And is dried in air at 20-40 ° C until the water content in the sorbent in an amount of 5 wt.%. 2. Sorbent for purification of atmospheric air from hydrogen sulfide, carbon dioxide and sulfur, made in the form of granules with a size of 0.5-5.0 cm from flask and Portland cement-500, containing, in terms of oxides, wt.%: CaO - 40, SiO ₂ - 35, Al ₂ O ₃ - 15 and additionally diethanolamine in an amount of 5 wt.% And water in an amount of 5 wt.%, And obtained by the method described in claim 1.