SU882590A1 - Catalyst for cleaning gas-air mixturs from carbon oxide - Google Patents

Description

one

The invention relates to catalysts for the purification of gaseous mixtures from toxic impurities, in particular carbon monoxide, and can be used to remove CO from gas process emissions and exhaust gases.

A palladium-rutheium catalyst for the purification of gas-air mixtures from carbon monoxide, containing up to 50% at. ruthenium on a carrier, in which it contains bentonite clay, alumina or silica gel f13.

The disadvantages of this catalyst are the content as an active additive of a precious metal (from the Pt group), the complexity of its synthesis, which includes, as a rule, processing products at high temperatures, often repeated, by tableting the resulting contact mass; low efficiency, especially in the case of Pt and Pd catalysts; low stability. (poisoning with water, ammonia, etc.).

The closest to the invention in technical essence and the achieved effect is a catcher for cleaning the gas-air mixtures from

carbon monoxide, comprising a copper-containing component, which is used as copper oxide, in the amount of 5-80 mol.%, cerium oxide and carrier - alumina G2.

A disadvantage of the known catalyst is insufficient activity. Thus, the oxidation of carbon monoxide on a known catalyst terminates at. The degree of oxidation is 95%, the volumetric rate is 1200 hours. 4 The purpose of the invention is to increase the activity of the catalyst.

The goal is achieved

15 in that the catalyst contains a copper-containing component — copper silicate on a carrier — silicon dioxide in the following ratio of components, wt.%:

Copper silicate 85.4-99.4

20 silica 0.6-14.6 Catalyst obtained by static treatment of a suspension of silica gel KSK 0.1 M solution

25 copper ammine in 0.3 M excess ammonia (pH 10.0), followed by washing the product with a weak solution of ammonia and water, which allows to obtain a product with a highly developed surface and a good 30

the number distribution of the active additive is copper silicate. The copper content in the resulting product is determined both by the difference in the concentrations of copper ions of the initial and equilibrium solutions, and by desorption of copper

from the solid product, after we extract it with its yolic acid (I;). In both cases, the copper content is determined by a chemical volumetric method (iodometric titration). The presence of copper silicate is confirmed by the X-ray method.

The process of CO removal; carried out under dynamic conditions in a catalytic tube at 275-300 ° C, a flow rate of 2700 of the initial concentration of carbon monoxide in a gas / air mixture of 0.5% by volume.

PRI me R 1. Silica gel brand KSK (solid - T) is poured with a 0.104 M solution of copper ammine (liquid - g); T: M “6.5: 1000.

. The interaction is carried out over a period of 40 days. The solution is drained, the resulting product is washed with approximately 0.3 M ammonia solution, then with distilled water (until a negative reaction to the NH ion). The wet precipitate is dried in air. A catalyst is obtained of the composition, wt.%: Copper silicate 85.4 and silica 14.6,

Wet gas-air, eat, contain. 0.5 about. The% CO is passed through a layer of 5 cm of catalyst with a volume of NOY at a speed of 2700 hours at 200; 300 C. Carbon monoxide is removed from the mixture at 2 ° C at 72%, at 275 ° C at 94%, at 300 ° C - at 100% . The stability of the catalysts for oxidation of III for 300 hours, which is 90%, i.e. a decrease in activity is not practically possible.

PRI mme R 2. Silica gel KSK grades are twice treated with copper ammonate solution. Original silica gel is poured with 0.1 g of 4 M pacTBojic copper ammine in 0.3 M excess of ammonia (T: F, 5: 1000) for 30 days. Then, the resulting product is treated with a 0.094 M solution of ammoniate honey (T1G "" 10: 1000) for 30 cyt. Upon completion of the interaction, the sample is separated from the liquid, for example, weak ammonia is used, then water and dried on. the air.

Get the catalyst composition, wt.% Silicate copper 95.2 and silica 4.8.

; a wet gas-air mixture containing 0.5% by volume of CO is passed through a slurry of 5 cm catylizer at a volume rate of 2700 ZOO-ZOO C. Carbon monoxide is removed from the mixture at 250 ° C by 74%; at - by 95%; at. - 100%. When you check the th-t job stability

CO oxidation catalyst for 300 hours, which is 90%, i.e. there is practically no decrease in catalyst activity.

Approx. 3. KSK brand silica gel is treated twice with a solution of copper mminacate. First, the interaction is carried out for 30 days with 0.104 M solution of copper ammonium salt (T: W 6.5: 1000), then for 45 days with a 0.094 M solution of copper ammine (T: Ж 10: 1000). Further The product is separated from the liquid phase, washed with ammonia and water and dried in air.

Get the product composition, wt.%: Copper silicate 99.4 and silicon dioxide 0.6.

A wet gas-air mixture containing 0.5 6b.% CO is passed through a layer of 5 cm of catalyst with a bulk velocity of 2700 hours at 2.00-300 C. Carbon monoxide is removed from the mixture at 25 Cic at 75%; at 215 C - by 95%; 300 - at 100%. At 275 ° C, the stability of the catalyst for the oxidation of CO for 300 hours, which is 90%, i.e. there is practically no decrease in catalyst activity.

Table 1 presents data on the activity of the catalyst according to the examples. 1-3 in the CO oxidation reaction. .

Table 1

Table 2 shows the comparative efficiency in the process of cleaning gas-air mixtures from carbon oxide; kind of present and known catalysts.

As can be seen from Table 4, the catalyst makes it possible to obtain at a given process (C ,, t) a greater degree of CO oxidation with a high stability of purification with time. Thus, almost 100% degree of carbon monoxide oxidation on the proposed catalyst is achieved at 27SC, on the prototype sample the oxidation ends at and on the analog sample at. A rather high degree of CO oxidation (75%) is achieved on the proposed catalyst already at. In comparison with the known catalysts, the proposed one is simpler in terms of composition, simpler and more effective in the preparation method, since its synthesis does not require the use of precious metals (Pd and Pt). In addition, it is stable in time during the oxidation of CO.

Table 2

Claims (2)

SUMMARY OF THE INVENTION Copper silicate 85.4-99.4 The catalyst for the purification of gas- · Silicon dioxide 0.6-14.6 sludge mixtures from carbon monoxide, including the copper component it is 1. The author's certificate of the USSR as a copper-containing component co, 217389, cl. <01 J 23/44, 1967. holds copper silicate, and as a carrier - silicon dioxide at barely- $ Q 2. USSR author's certificate with the corresponding ratio of components, No. 212994, cl. In 01 J 23/32, 1966 wt.%:. (prototype). , VNIIIPI Order 10042/9 Circulation 570 Subscription Branch of PPP Patent, Uzhgorod, Project 4,