Science and Education in Karakalpakstan issn 2181-9203 Science Magazine chief editor

2H
2
S + SO
2 
→ 3S + 2H
2
O
Catalysts consist of alumina, titanium oxide, as well as their mixture. In the Claus process, it 
is also possible to form sulfur by the direct oxidation of hydrogen sulfide: 
2H
2
S + O
2 
→ 2S + 2H
2
O
Chemisorption purification 
[5; 8]
When organosulfur substances and H
2
S interact with metals and their oxides, the following 
reactions can occur (Me is a metal: Zn, Cu, Fe, etc.): 
MeO + H
2
S → MeS + H
2
O,
MeO + C
n
H
2n+1 
SH
→ MeS + H
2
O + C
n
H
2n
,
MeO + 2C
n 
H
2n+1 
SH → MeS + H
2
O + (C
n
H
2n+1 
)
2
S,
MeO + (C
n 
H
2n+1 
)
2
S → MeS + H
2
O + 2C
n
H
2n 
,
MeO + COS → MeS + CO
2
,
2MeO + CS 
2 
→ 2MeS + CO
2
,
Me + H
2
S → MeS + H
2
,
Me + C
n
H
2n+1 
SH → MeS + C
n
H
2n+2
,
Me + (C
n
H
2n+1
)
2 
S → MeS + C
n
H
2n+2 
+ C
n
H
2n
At present, due to the development of various methods of desulfurization, the use of 
processes based on the chemisorption of hydrogen sulfide by sorbents based on iron oxides at low 
temperatures (optimum sorption temperature 28–30°C) occupies a very modest place in industry. 
Their main disadvantage is the release of sulfur compounds into the gas flow when water vapor 
enters the already sulphurized sorbent [9-10]. 
For fine purification of water gas, an iron-soda sulfur cleaning mass is used, consisting of 
Fe
2
O
3 
(40–45%), Na
2
CO
3 
(30%), Al
2
O
3 
, SiO
2 
, CaO, etc. The process is very effective. for cleaning 
from COS, CS 
2 
and RSH. It is carried out at relatively low temperatures (150–200°C), and the 
residual content of sulfurous substances can be below 1 mg/m
3
. 
Very cheap chemisorbents based on iron oxides are used to purify gases with sulfur content 
up to 2–3 g/m
3
. However, the allowable space velocities on such chemisorbents are 5–10 times 

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Science and Education in Karakalpakstan. 2023 №2/1 ISSN 2181-9203 
39 
lower than on active zinc and copper oxide. On the other hand, it is stated in [10]
 
that Fe
2
O
3 
is 
superior to
CaO and ZnO as a high-temperature absorber. 
Desulfurization masses based on oxides of zinc, copper, and chromium are mainly used, 
which have become widely used. Chemisorbents can also be used for single-stage purification, if 
the initial gas contains practically only H
2
S or organosulfur substances in an amount of not more 
than 5–7 mg/m
3 
(the content in the purified gas is not more than 0.5–1 mg/m
3
). With their larger 
amount in the initial gas, chemisorbents work effectively only when two-stage purification is used. 
In the case of ZnO and CuO, the process proceeds at temperatures of 250–400°C. 
Chemisorbents containing CuO should be reconstituted before use, while CuO turns into Cu and 
Cu
2
O for chemisorption purification of gases from hydrogen sulfide has appeared, associated with 
the development of oil fields in the North Sea. 
The alkanolamine plants commonly used for these purposes in the oil industry are in 
themselves unacceptable in this case due to their large weight and dimensions and the need for 
steam to regenerate the absorbent. Johnson Company Matthey has developed a new efficient zinc 
oxide chemisorbent with the brand name ICI 75-1 for offshore oil platforms. This sorbent has a high 
specific surface area, which makes it possible to use it at relatively low temperatures. It is 
characterized by a slightly lower density, but practically the same mechanical strength as the ICI 
32-4 chemisorbent, which is produced for gas purification in the production of ammonia and 
methanol. 
The results of comparative tests on a pilot plant of both chemisorbents in the purification of 
natural gas containing 0.2% vol. H
2
S and 4.0% vol. CO
2 
showed that their dynamic capacity (as a 
percentage of the theoretically possible) at a space velocity of 1000 h
-1 
depends on temperature as 
follows (Table 1).