SU1691294A1 - Method of producing elementary sulfur - Google Patents

Abstract

The invention relates to methods for processing acidic H25-containing gases, in particular, to methods for producing elemental sulfur in Claus units. The aim of the invention is to increase the sulfur yield and reduce the emissions of sulfur, clear compounds into the atmosphere. The process is conducted with a sequential (periodic) change in the sequence of operation of each catalytic stage along the gas flow so that the first stage becomes the second, the second - the third, and the third - the first. In addition, the temperature of the second stage is changed — it is set 50–80 K below the first, which ensures the operation of the ace catalytic stages under conditions close to optimal. The method provides 99.58% degree of conversion of H2S to S 1 Il.

Description

The invention relates to the processing of acidic H25-containing gases, in particular, to methods for the production of elemental sulfur in Claus units.

 The invention is an increase in the yield of the target product by increasing the degree of conversion of hydrogen sulfide to sulfur.

Example. The method is carried out on an installation comprising one thermal and three catalytic stages, according to the scheme shown in the drawing. The installation contains a reactor-generator 1, combined with a waste-heat boiler, heater 2, catalytic reactor 3, sulfur condenser 4, heater1 5, catalytic reactor 6, sulfur condenser 7, catalytic reactor 8, sulfur condenser 9, sulfur catcher 10, furnace 11 afterburners, valves 12-29.

Catalysts based on active alumina or titanium dioxide can be used in the process.

Acidic H23-containing gas is burned in the furnace of the reactor-generator 1, combined with a waste-heat boiler. In the furnace at 900-1400 ° C, the incomplete combustion of H2 $ occurs with the formation of elemental sulfur and sulfur dioxide. In the utilization boiler, the process gas is cooled to 170-300 ° C with condensation of the sulfur formed, and then with a volume concentration ratio of H25 and 502 2: 1 is sent to the preheater 2, where it is heated to 220-270 ° C. The heated gas through the valve 12 enters the catalytic reactor 3, where the formation of elemental sulfur occurs during the reaction of H2S and S02

2H2S + SQ24-3S + 2H20 + Q. (1) and through valve 13 is sent to sulfur condenser 4, where the gas is cooled, for example.

oh oh

Yu

2

boiling water and the sulfur formed condenses. Next, the gas is heated in the preheater 5 to 190-250 ° C and through the valve 14 enters the catalytic reactor 6, and from there through the valve 15 to the condenser 7. The gas cooled to 130-160 ° C through the valve 16 enters the reactor 8 and through the valve 17 to the condenser 9. The gas is then transferred through a sulfur catcher 10 to remove the dropping sulfur and sent to the furnace 11 to oxidize all the sulfur compounds to S02.

The reactor 8 operates at a temperature below the sulfur dew point, and all the sulfur formed by the reaction (1) accumulates in the catalyst bed. Prm achieve a certain amount of sulfur capacity, which is determined by the properties of the catalyst used and is 10-60 wt.%, The valves are switched ( valves 18-23 are open), and the process gas after the heating of heater 2 passes through catalytic reactors in the sequence 8, 3, 6. When a given sulfur-holding capacity is reached, valves 24-29 (the rest are closed) are opened in the reactor 6 and the gas passes catalytically e reactors used in the sequence, 8, 3. Then, the process is repeated, the process duration between switching valves depend on the hydrogen sulphide concentration in the processed gas volumetric gas velocity through the catalyst bed and the catalyst employed.

In the case of gas processing with a HaS content of 80 vol.% And a space velocity of 500 hours using a catalyst based on active alumina, the cycle time between switching the valve is 24 hours.

at the same time, the initial hydrogen sulfide to elemental sulfur reaches 99.58%.

The proposed method allows to increase the degree of conversion of hydrogen sulfide on

0.47% compared with the known method.

In addition, in the proposed method

each of three catalytic reactors

periodically works as the first in the course

gas and is in contact with the gas flow,

containing a reducing agent (NgZ) at a high temperature, which leads to the pp depletion of sulfates that poison the catalyst, and maintains the catalyst's activeness at a stable level, i.e. increases term

catalyst services.

Claims (1)

Claims The method of obtaining elemental sulfur from sulfur-containing gases by the Claus method, including thermal and three catalytic stages with a change in the sequence of operation of the catalytic stages along the gas and with intermediate separation of sulfur formed by condensation, characterized in that sulfur, by increasing the degree of conversion of hydrogen sulfide to sulfur, at the third stage along the gas, the temperature is constantly maintained below the dew point of sulfur vapor, and the sequence of operation of the catalytic stages is changed when the desired sulfur content of the catalyst at the third stage is reached so that the first stage is switched to the place of the second, second to the place of the third, and the third - to the place first, with each switching of the last reactor to the place of the first along the gas flow, the direction of gas flow in this reactor is reversed at the same time. cn J ° UC jlсч V r-fcLx r-tXfcrJ /