RU2612481C1 - Method of obtaining sulphur from exhaust metallurgical gases - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: in order to obtain sulfur from exhaust metallurgical gases containing sulfur oxide (IV) SO₂ and oxygen O₂, SO₂ is reduced by gas containing carbon monoxide CO and hydrogen H₂, in a hollow reactor at a temperature of 1100-1350°C. Next, the resulting reduced gas is processed in a catalytic reactor with an aluminium oxide catalyst. An additional amount of gas comprising carbon monoxide and hydrogen is fed into the hollow reactor, to obtain a gas containing hydrogen sulfide H₂S, carbonyl sulphide COS, CO, water, H₂ and unreacted SO₂. The resulting gas is fed into thesulfur condenser to condense it, and then tosulfur production unit by Claus method. Above mentioned temperature is maintained in the hollow reactor by changing the flow of the gas comprising carbon monoxide and hydrogen. Before feeding the mentioned reduced gas to the catalytic reactor, it is cooled in a waste-heat boiler to a temperature of 350-450°C. The catalytic reduction of SO₂ by gas containing carbon monoxide and hydrogen is carried out at a space velocity of 250-500 hr^-1 and at a temperature in a catalyst layer of 400-500°C.

EFFECT: invention ensures higher grade of sulfur extraction from gases and simplifies the process.

18 cl, 1 dwg,1 tbl, 1 ex

Description

FIELD OF TECHNOLOGY

The invention relates to chemical technology, and more specifically to methods for producing elemental sulfur from exhaust gases containing sulfur oxide (IV).

BACKGROUND

In the production of non-ferrous metals by the pyrometallurgical method, the inevitable emission of exhaust gases containing sulfur oxide (IV) occurs, the concentration of which depends on the technology of smelting metallurgical raw materials. The problem of sulfur utilization from waste metallurgical gases is urgent and the need to solve it is determined not only by economic factors, but also by increasing requirements for protecting the environment from harmful industrial gas emissions. Currently, exhaust gases are mainly used to produce sulfuric acid, which is widely used in various sectors of the economy. However, in some cases, in the absence of consumers of sulfuric acid, it is advisable to utilize the exhaust gases to produce elemental sulfur, which, compared with sulfuric acid, is much easier to transport and store in an open warehouse.

In connection with the foregoing, for example, the Gintsvetmet Institute has developed a high-temperature version of the methane method for the production of sulfur from autogenous off-gas processes, based on the reduction of sulfur (IV) oxide by natural gas in a hollow reactor at a temperature of 1250–1300 ° С with the subsequent processing of the reduced gas by the method Klaus (see publications: Eryomin O.G., Eryomina G.A. Utilization of sulfur from non-ferrous metal waste gases “Non-ferrous metals”, 1996, No. 4, P. 21 ÷ 23; Eryomin O.G., Eryomina G.A. On the production of sulfur from waste metallurgical non-ferrous metals, 2000, No. 3, pp. 26–28; Tarasov A.V., Eryomin OG Improving the technology for producing sulfur from waste metallurgical gases Non-ferrous metals, 2004, No. 10, p. 41 ÷ 43). This technology with one Klaus stage was implemented on an industrial scale at the NMMC in the utilization of exhaust gases from the Vanyukov furnace containing sulfur oxide (IV). Long-term operation of an industrial installation for sulfur production showed that the process is characterized by the simplicity of the technological scheme, reliability and safety. This ensures the receipt of marketable sulfur of the highest grade 9985 according to GOST-127 ÷ 76, which allows it to be used to produce sulfuric acid according to the so-called "short" scheme. However, this method of producing sulfur (the so-called "methane" method) has a significant drawback, which consists in the increased consumption of expensive natural gas - up to 1000 nm ³ per 1 ton of sulfur produced (units of "nm ³ " mean cubic meter, in terms of per volume under normal conditions). Currently, the price of natural gas is 300–350 dollars per 1000 nm ³ , and the price of sulfur is 50 dollars per ton. At such costs, the production of sulfur in a known "methane" way is unprofitable, if you do not take into account the beneficial environmental effect (damage from air pollution).

Thus, when obtaining sulfur from waste metallurgical gases, it seems appropriate to use other, cheaper and more efficient reducing agents, for example, gas containing carbon monoxide and hydrogen obtained by coal gasification. A gas containing carbon monoxide and hydrogen contains significant amounts of carbon monoxide and hydrogen, which are effective reducers of sulfur oxide (IV).

Numerous research results on the reduction of sulfur oxide (IV) by carbon monoxide and hydrogen to produce sulfur are presented in the domestic and foreign literature. All these data mainly show the high efficiency of the reducing agents and the possibility of obtaining a high degree of conversion of sulfur oxide (IV) to sulfur. However, all these results were obtained in laboratory conditions using chemically pure reagents. In this case, the real composition of metallurgical gases, in particular the presence of oxygen and moisture in the gas, was not taken into account. For this reason, no specific technologies have been proposed for producing sulfur from waste metallurgical gases.

It is known that modern technologies for producing sulfur from gases were developed relatively recently, in the second half of the twentieth century. It is necessary to especially note the process of sulfur production, based on the catalytic reduction of sulfur dioxide by natural gas. This method involves the catalytic reduction of sulfur (IV) oxide by natural gas by preheating a mixture of the source gas and natural gas in a regenerative heat exchanger from 450 ° C to 1100 ° C, after which the heated mixture of gases is fed to a catalytic reactor in which sulfur oxide (IV) restore natural gas to elemental sulfur. The recovered gas at a temperature of 1100 ° C passes through a second regenerative heat exchanger, in which the gas is cooled to 450 ° C and at the same time the regenerative heat exchanger nozzle is heated. After heating this heat exchanger, it is used to heat the source gas before being fed to the catalytic reactor, and the first regenerative heat exchanger is used to cool the reduced gas while heating its nozzle to 1100 ° C. Thus, the normal operation of the catalytic reactor is ensured by periodic switching of the gas flows to pass them through regenerative heat exchangers (US patent No. 4039650). The disadvantage of this method is the complexity of the technological scheme and the need to use regenerative heat exchangers with a heat nozzle and heat-resistant valves of complex design to change the direction of flow of aggressive gas containing SO ₂ and H ₂ S at temperatures up to 1100 ° C.

A known method for the conversion of gases containing sulfur oxide (IV), obtaining sulfur by passing the gas mixture through a catalyst bed, which is periodically heated to the temperature of the beginning of the conversion reaction, while heating is resumed when the catalyst is cooled over the entire height of the layer (USSR copyright certificate No. 1157013) . The disadvantage of this method is the need for periodic heating of the catalyst, which complicates the technological scheme of the process and requires the use of a complex automatic control system. Periodic heating of the catalyst leads to its rapid destruction and the need for frequent replacement.

The closest in technical essence to the claimed method is a method of recovering an oxygen-containing gas by natural gas by preliminary burning part of the natural gas in a prechamber at a temperature of 1470 ° C, after which additional excess natural gas is fed into the formed thermal zone in the absence of oxygen, which, according to the authors, accelerates recovery process (RF patent for the invention No. 2137705). The disadvantage of this method is that when using gas containing carbon monoxide and hydrogen as an SO2 reducing agent, if the oxygen in the initial metallurgical gas is up to 10%, the gas mixture will overheat to a temperature of more than 1350 ° C, which will reduce the sulfur yield.

The possibility of carrying out processes of deoxygenation of gases and reduction of SO2 will require the creation of a complex system of heat removal from the reaction zone.

SUMMARY OF THE INVENTION

The objective of the invention is to provide a simple and effective technology for the disposal of sulfur dioxide gases to produce sulfur, based on the reduction of sulfur oxide (IV) by a gas containing carbon monoxide and hydrogen, increasing the degree of extraction of sulfur from gases and simplifying the process.

The problem is solved due to the fact that in the method for producing sulfur from waste metallurgical gases containing sulfur dioxide (IV) (SO ₂ ) and oxygen (O ₂ )

(a) reduce SO ₂ with a gas containing carbon monoxide (CO) and hydrogen (H ₂ ) in a hollow reactor at a temperature of 1100 ÷ 1350 ° C,

(b) the reduced gas obtained in stage (a) is processed in a catalytic reactor with an alumina catalyst, to which an additional amount of gas containing carbon monoxide and hydrogen is fed to produce a gas containing hydrogen sulfide (H ₂ S), carbonyl sulfide ( COS), CO, water (H ₂ O), H ₂ and unreacted SO ₂ ,

(c) supplying the gas obtained in step (b) to a sulfur condenser to condense it, and then to the sulfur production plant using the Claus method,

characterized in that in it

(b1) said temperature in the hollow reactor in step (a) is maintained by changing the flow rate of a gas containing carbon monoxide and hydrogen, and

(b2) before feeding said reduced gas obtained in stage (a) into said catalytic reactor, it is cooled in a recovery boiler to a temperature of 350 ÷ 450 ° C

(b3) catalytic reduction of SO ₂ with a gas containing carbon monoxide and hydrogen is carried out at a space velocity of 250-500 h ^-1 and a temperature in the catalyst bed of 400 ÷ 500 ° C.

In one embodiment of the method, when processing gases with an SO ₂ content _of more than 10%, the catalytic reduction in step (b) is carried out by means of the aforementioned reactor with a multilayer catalyst, while between the said layers the gas is additionally cooled to a temperature of 350 ÷ 450 ° C.

In yet another embodiment of the method, when processing gases with an SO ₂ content _of more than 10%, the catalytic reduction in step (b) is carried out by means of the reactor with a multilayer catalyst, while between the said layers the gas is additionally cooled to a temperature of 500 ÷ 950 ° C by changing the flow rate said gas containing carbon monoxide and hydrogen.

In another embodiment of the method, when starting up said reactor, the catalyst is preheated to a temperature of 350 ÷ 450 ° C with flue gas from burning gas containing carbon monoxide and hydrogen in an oxygen-air mixture.

In one embodiment of the method, the catalytic reduction of SO ₂ with a gas containing carbon monoxide and hydrogen is carried out in step (b) at a space velocity of 200 ÷ 500 h ^-1 .

In another embodiment of the method, the amount of gas containing carbon monoxide and hydrogen supplied to the said reactor in step (b) is controlled by the composition of the reduced gas, taking into account its subsequent conversion to sulfur by the Klaus method.

In another embodiment of the method, a gas containing carbon monoxide and hydrogen contains carbon monoxide in an amount of 35 ÷ 40% and hydrogen in an amount of 47 ÷ 52%.

As will be understood from the present text as a whole, the problem is solved by supplying exhaust oxygen-containing gases and a gas containing carbon monoxide and hydrogen containing CO and H ₂ to the hollow reactor. Moreover, due to the interaction of carbon monoxide and hydrogen with oxygen present in the source metallurgical gas, the gas mixture is heated depending on the oxygen content in the source gas. The heating process is accompanied by the following chemical reactions:

Technological calculations show that one percent of oxygen provides an increase in the temperature of the gas mixture by 110 ° C.

With complete deoxygenation of the gas mixture at a temperature of 1100 ÷ 1350 ° C and an excess of gas containing carbon monoxide and hydrogen, the process of reduction of sulfur oxide (IV) by carbon monoxide and hydrogen proceeds according to the reactions:

At the same time, reactions of the formation of hydrogen sulfide and carbonyl sulfide are possible:

Reactions 3 and 4, as well as reactions 1 and 2, proceed with the release of heat, causing additional heating of the gas mixture to a temperature of 1300 ÷ 1350 ° C, which is supported by the regulation of the flow of gas containing carbon monoxide and hydrogen. The recovered gas containing H ₂ S, COS, CO ₂ , H ₂ O, H ₂ , CO, S ₂ and unreacted SO ₂ is fed to a recovery boiler, in which the gas is cooled to a temperature of 350 ÷ 400 ° C, and then to catalytic reactor with three catalyst beds. At this temperature, 3 ÷ 6 reactions occur on the catalyst. The catalyst used is granular active alumina Al ₂ O ₃ or other alumina catalysts. The amount of gas containing carbon monoxide and hydrogen supplied to the catalytic reactor is also controlled by the temperature in the first and second catalyst beds, which should be in the range of 450 ÷ 900 ° C depending on the concentration of SO ₂ in the gas at the inlet to the catalytic reactor.

When the gas temperature at the outlet of the catalytic layer reaches 900 ° C, it is cooled in the intermediate economizer to a temperature of 350 ÷ 400 ° C and fed to the second catalyst layer in a mixture with an additional amount of gas containing carbon monoxide and hydrogen, which is controlled by the temperature of the gas at the outlet by analogy with the operation of the first catalyst layer.

BRIEF DESCRIPTION OF THE DRAWING

The drawing shows a flow diagram of a process for producing sulfur by reducing sulfur (IV) oxide with a gas containing carbon monoxide and hydrogen.

In the drawing, the following notation:

1 - high temperature hollow reactor;

2 - catalytic reactor;

3 - sulfur capacitor;

4 - inlet of a gas containing carbon monoxide and hydrogen;

5 - gas outlet (for the Klaus process);

6 - sulfur output;

11 - waste metallurgical gases containing sulfur dioxide (IV) (SO2) and oxygen (O2);

7, 8, 9 and 10 - connecting pipelines.

DETAILED DESCRIPTION OF THE INVENTION

To determine the optimal volumetric rate and temperature of the catalytic reduction of SO _{2 by a} gas containing carbon monoxide and hydrogen, laboratory and semi-industrial studies were carried out.

When conducting research, the temperature in the catalytic reactor varied in the range of 300 ÷ 800 ° C. The concentration of SO ₂ in the feed gas was 10–30%. The experiments were carried out at a space velocity in the reactor: 125, 250, 500 and 1000 h ^-1 .

The initial gas composition in front of the reactor and the composition of the recovered gas were determined by the chromatographic method, and the flow rate of air and sulfur oxide (IV) was controlled using laboratory rheometers.

According to the results of analyzes of the source and reduced gas, the degree of conversion of sulfur oxide (IV) to sulfur was determined by the formula:

,

SO₂ в исходном и в восстановленном газе;Where

,

SO₂ in the source and in the reduced gas;

- коэффициент, учитывающий изменение объема газа при восстановлении;

- coefficient taking into account the change in gas volume during recovery;

,

- концентрация азота в исходном и восстановленном газе. Первая серия опытов по каталитическому восстановлению оксида серы (IV) монооксидом углерода проводилась с целью определения влияния температуры на степень конверсии SO₂ в серу. Результаты исследований, проведенных при объемной скорости 250 час¹ при изменении температуры в интервале 290÷500°С, представлены в таблице 1. Объемная скорость определялась как количество газовой смеси 250 л/час, которое проходило через 1 литр катализатора. Из полученных данных видно, что в восстановленном газе присутствуют сероводород и карбонилсульфид, а также остаточные количества оксида серы (IV) и монооксида углерода. Однако по сравнению с высокотемпературным вариантом метанового способа получения серы применение в качестве восстановителя SO2 газа, содержащего монооксид углерода и водород, при каталитическом восстановлении обеспечивает более высокий выход серы при минимальных содержаниях сероводорода и карбонилсульфида.

,

- the concentration of nitrogen in the source and reduced gas. The first series of experiments on the catalytic reduction of sulfur (IV) oxide with carbon monoxide was carried out in order to determine the effect of temperature on the degree of conversion of SO ₂ to sulfur. The results of studies conducted at a space velocity of 250 hours ¹ with a temperature change in the range 290 ÷ 500 ° C are presented in table 1. The space velocity was determined as the amount of gas mixture 250 l / h, which passed through 1 liter of catalyst. It can be seen from the obtained data that hydrogen sulfide and carbonyl sulfide are present in the reduced gas, as well as residual amounts of sulfur oxide (IV) and carbon monoxide. However, in comparison with the high-temperature version of the methane method for producing sulfur, the use of a gas containing carbon monoxide and hydrogen as a SO2 reducing agent during catalytic reduction provides a higher sulfur yield with minimal contents of hydrogen sulfide and carbonyl sulfide.

Analyzing the presented results, we can conclude that in the temperature range in the catalyst bed 400 ÷ 500 ° C at a space velocity of 250 h ^{-1 the} maximum degree of conversion of SO ₂ to sulfur is 95 ÷ 96%. When the temperature decreases to 370 ° C, the degree of conversion gradually decreases to 89.9% with a corresponding increase in the concentrations of SO ₂ , H ₂ S, COS in the reduced gas. Therefore, the catalytic reduction of SO ₂ with a gas containing carbon monoxide and hydrogen must be carried out at a space velocity of approximately 250–500 h ⁻¹ and a temperature in the catalyst bed of approximately 400–500 ° C.

The studies showed that when the content of sulfur (IV) oxide in the initial metallurgical gas is more than 25–30%, three catalyst beds with intermediate cooling of the gas between the layers are necessary. After passing through the last layer, the reduced gas is supplied to the sulfur condenser for condensation and then to the Klaus installation for processing formed in the catalytic reactor of hydrogen sulfide by reaction (7):

In this regard, the supply of gas containing carbon monoxide and hydrogen is further adjusted by the content of hydrogen sulfide and unreacted sulfur (IV) oxide in the reduced gas at the outlet of the catalytic reactor, maintaining a 2: 1 ratio of hydrogen sulfide and sulfur oxide (IV).

The method is carried out as follows: as shown in FIG. 1, waste metallurgical gases containing, after wet cleaning from dust, 10 ÷ 50% SO ₂ and 4 ÷ 12% О ₂ are mixed with a gas containing carbon monoxide and hydrogen, and fed into a hollow high-temperature reactor 1, which is preheated to a temperature of 1100 ÷ 1300 ° C by burning gas containing carbon monoxide and hydrogen in air. At this temperature, the oxygen contained in the initial metallurgical gas reacts with carbon monoxide and hydrogen of the gas containing carbon monoxide and hydrogen in accordance with reactions 1 and 2.

Thus, the amount of gas containing carbon monoxide and hydrogen for deoxygenation of the initial metallurgical gas is determined from the ratio (V _CO + V _H2 ) / V _O2 = 2, where V _CO , V _H2 is the volume of carbon monoxide and hydrogen in the gas containing carbon monoxide and hydrogen, respectively, and V _O2 is the volume of oxygen in the initial metallurgical gas.

With a subsequent increase in the supply of gas containing carbon monoxide and hydrogen to the hollow reactor, sulfur (IV) oxide is reduced to form sulfur and hydrogen sulfide, as well as in small quantities of carbonyl sulfide. The recovery process is accompanied by the occurrence of chemical reactions 3, 4 and 5, 6, which also lead to additional heating of the gas mixture in a hollow reactor. The amount of gas containing carbon monoxide and hydrogen supplied to the reduction of SO _{2 is} regulated by the temperature of the gases at the outlet of the hollow reactor, which should be in the range of 1250 ÷ 1350 ° C. The recovered gas at this temperature is then fed to a recovery boiler for cooling to a temperature of 350 ÷ 450 ° C.

After cooling the gas in the recovery boiler, it is fed in a mixture with an additional amount of gas containing carbon monoxide and hydrogen for catalytic reduction in a catalytic reactor 2, which includes two or three layers of catalyst depending on the initial concentration of SO ₂ in the initial metallurgical gas. Previously, the first catalyst layer is heated to a temperature of 400 ÷ 450 ° C with flue gases obtained from the combustion of gas containing carbon monoxide and hydrogen in air.

The amount of gas containing carbon monoxide and hydrogen supplied to the first catalyst layer is controlled by the gas temperature at the outlet of the layer, which should be in the range of 500 ÷ 900 ° C depending on the concentration of SO ₂ in the gas at the inlet to the catalytic reactor.

The catalytic reduction process is carried out at a space velocity of 150 ÷ 500 h ^-1 , preferably 250 h ^-1 . The amount of catalyst loaded into the catalytic reactor is determined taking into account the space velocity according to the equation:

V _K = V _G / W, where V _K is the volume of the catalyst, m ³ ,

V _G - the amount of source gas, nm ³ / hour,

W is the volumetric rate of the process, hour ^-1 .

When the content of SO ₂ in the initial metallurgical gas 25 ÷ 30% will require three layers of catalyst. In this case, the gas after the first catalyst layer is cooled in an economizer to a temperature of 400 ÷ 450 ° C and fed to the second catalyst layer in a mixture with an additional amount of gas containing carbon monoxide and hydrogen. The temperature in the second catalyst bed should be in the range of 500 ÷ 600 ° C. If this temperature is exceeded, a third catalyst layer (sanitary layer) is required to complete the SO ₂ reduction process. After the second catalyst bed, the reduced gas is cooled in an economizer by analogy with gas cooling after the first bed to a temperature of 400 ÷ 450 ° C and is fed to the third bed. The content of H ₂ S and SO ₂ in the gas after passing through the third layer should correspond to the ratio V _H2S / V _SO2 = 2, which is necessary for the efficient operation of the Claus stage. This ratio is ensured by regulating the supply of gas containing carbon monoxide and hydrogen to the second catalyst bed. The recovered gas after the third catalyst bed 450 ÷ 550 ° C enters the sulfur condenser 3 and then is fed to the Claus unit for refinement - H ₂ S.

EXAMPLE 1

Waste metallurgical gases in an amount of 68000 nm ³ / hour after wet dusting, containing 8% O ₂ and 28.3% SO ₂ are fed into a hollow high-temperature reactor, which is preheated to a temperature of 1100 ÷ 1200 ° C with flue gases from gas combustion containing carbon monoxide and hydrogen in air. A gas containing carbon monoxide and hydrogen containing about 40% CO and 50% H ₂ is obtained from coal by the steam-water conversion method.

Simultaneously with the supply of metallurgical gas to the hollow reactor, a gas containing carbon monoxide and hydrogen is supplied. In this case, deoxidation of the initial metallurgical gas occurs due to the interaction of carbon monoxide and hydrogen contained in the gas containing carbon monoxide and hydrogen, according to reactions 1 and 2. At the same time, the process of reducing SO ₂ with an excess of gas containing carbon monoxide and hydrogen proceeds according to the reactions 3, 4 and 5, 6, which leads to additional heating of the gas mixture. The amount of supplied gas containing carbon monoxide and hydrogen to the hollow reactor is controlled by the temperature of the reduced gas, which should not exceed 1350 ° C. At the same time, a complete deoxygenation of the gas and partial reduction of SO ₂ with the formation of sulfur in accordance with the equilibrium yield are ensured in the hollow reactor. Based on technological calculations and semi-industrial tests, it was found that for a given composition and amount of the source gas, complete deoxygenation is ensured when 6200 nm ³ / h is supplied to the hollow reactor when the temperature in the reactor increases to 1070 ° C.

The recovered gas containing sulfur vapor and unreacted sulfur dioxide is then fed to a recovery boiler to cool the gas to a temperature of 350 ÷ 450 ° C, after which it is fed to a catalytic reactor having three layers of alumina catalyst. The load of the catalyst in the catalytic reactor is calculated taking into account the volumetric process rate of 500 h ^-1 . At the same time, gas containing carbon monoxide and hydrogen is supplied to the first and second catalyst beds. The reduction of SO _{2 with} carbon monoxide and hydrogen in a catalytic reactor also proceeds with the release of heat, causing an increase in gas temperature after passing through each catalyst bed.

The total heating of the gas at a degree of conversion of sulfur oxide (IV) to sulfur 50% is 600 ° C. As mentioned above, during the reduction of sulfur (IV) oxide in a hollow reactor, the increase in gas temperature will be 1350-1070 = 280 ° С. Then the increase in gas temperature in the catalytic reactor will be 320 ° C. The amount of gas supplied containing carbon monoxide and hydrogen to the first catalyst layer is controlled by the gas temperature at the outlet of the layer, which should be in the range of 600 ÷ 650 ° C, and the temperature of the gases at the outlet of the second layer is maintained in the range of 500 ÷ 550 ° C also by changing the flow rate of a gas containing carbon monoxide and hydrogen supplied to the second layer. The amount of gas containing carbon monoxide and hydrogen supplied to the second catalyst bed is adjusted according to the composition of the reduced gas, in which the content of hydrogen sulfide and unreacted sulfur oxide (IV) must correspond to a ratio of 1: 2, which, as mentioned above, is necessary for the subsequent processing of the reduced gas at the Claus installation. Steam-water economizers are used to cool the gas between the catalyst layers to a temperature of 400 ÷ 450 ° C.

The third catalyst bed completes the reduction of sulfur (IV) oxide with carbon monoxide and hydrogen. The increase in gas temperature after passing through the third catalyst layer will be insignificant within the fluctuation of the concentration of SO ₂ in the initial metallurgical gas. The gas temperature after the third catalyst bed should be in the range of 500 ÷ 550 ° C. The recovered gas after the catalytic reactor with an initial SO ₂ concentration _of 27.0% in the metallurgical gas will contain H ₂ S 4.5%, SO ₂ 2.5% and COS 1.5%. The formation of COS is explained by the reaction of carbon monoxide with sulfur vapor. Carbon monoxide and hydrogen are almost completely absent. This indicates the normal operation of the catalytic reactor and the optimal flow rate of gas containing carbon monoxide and hydrogen supplied to the first and second catalyst layers.

Determination of the main dimensions of the catalytic reactor

When the volume of metallurgical gas is 60,000 nm ³ / hour, the volume of gas supplied to the catalytic reduction is 66400 nm ³ / hour. We install two reactors operating in parallel, processing at 33200 nm ³ / hour. At a space velocity of 500 h ^−1, the catalyst volume will be 33,200 / 500 = 66.4 m ³ .

With a height of three catalyst layers of 1.5 m, the reactor cross section will be 33.2 m ² , respectively, the diameter of the reactor will be 6.5 m.

Claims (14)

1. A method of producing sulfur from waste metallurgical gases containing sulfur dioxide (IV) (SO ₂ ) and oxygen (O ₂ ), in which (a) reduce SO ₂ with a gas containing carbon monoxide (CO) and hydrogen (H ₂ ) in a hollow reactor at a temperature of 1100 ÷ 1350 ° C, (b) the reduced gas obtained in stage (a) is processed in a catalytic reactor with an alumina catalyst, to which an additional amount of gas containing carbon monoxide and hydrogen is fed to produce a gas containing hydrogen sulfide (H ₂ S), carbonyl sulfide ( COS), CO, water (H ₂ O), H ₂ and unreacted SO ₂ , (c) supplying the gas obtained in step (b) to a sulfur condenser to condense it, and then to the sulfur production plant using the Claus method, characterized in that in it (b1) said temperature in the hollow reactor in step (a) is maintained by changing the flow rate of a gas containing carbon monoxide and hydrogen, and (b2) before feeding said recovered gas obtained in stage (a) into said catalytic reactor, it is cooled in a recovery boiler to a temperature of 350 ÷ 450 ° C (b3) the catalytic reduction of SO ₂ with a gas containing carbon monoxide and hydrogen is carried out at a space velocity of 250 ÷ 500 h ^-1 and a temperature in the catalyst bed of 400 ÷ 500 ° C. 2. The method according to p. 1, characterized in that during the processing of gases with an SO ₂ content _of more than 10%, the catalytic reduction in stage (b) is carried out by means of the aforementioned reactor with a multilayer catalyst, while the gas is additionally cooled between the said layers to a temperature of 350 ÷ 450 ° C. 3. The method according to p. 1, characterized in that in the processing of gases with an SO ₂ content _of more than 10%, the catalytic reduction in step (b) is carried out by means of the aforementioned reactor with a multilayer catalyst, while the gas is additionally cooled between the said layers to a temperature of 500 ÷ 950 ° C by changing the flow rate of said gas containing carbon monoxide and hydrogen. 4. The method according to p. 1, characterized in that when the reactor is started up, the catalyst is preheated to a temperature of 350 ÷ 450 ° C with flue gas from burning gas containing carbon monoxide and hydrogen in an oxygen-air mixture. 5. The method according to p. 1, characterized in that it catalytic reduction of SO ₂ with a gas containing carbon monoxide and hydrogen, in stage (b) is carried out at a space velocity of 200 ÷ 500 h ^-1 . 6. The method according to p. 1, characterized in that the amount of gas containing carbon monoxide and hydrogen supplied to the said reactor in stage (b) is corrected for the content of hydrogen sulfide and unreacted sulfur oxide (IV) in the reduced gas at the outlet of catalytic reactor, maintaining the ratio of hydrogen sulfide and sulfur oxide (IV) 2: 1. 7. The method according to p. 1, characterized in that it contains gas containing carbon monoxide and hydrogen, contains carbon monoxide in an amount of 35 ÷ 40% and hydrogen in an amount of 47 ÷ 52%.

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