A system for producing sulfur from desorbed gas by a full dry method

Abstract

The application provides a kind of desorption gas preparation sulfur system of full dry method, and sequentially passes through import valve group, hydrolysis tower, temperature control device, selective oxidation tower, claus reaction tower, condensation crystallization system, dust remover, export valve group along desorption gas flow direction;Import valve before, export valve group after through third branch pipe and parallel system cooling bypass valve;The pipeline that hydrolysis tower is connected with temperature control device is provided with first branch pipe, and first branch pipe is connected after selective oxidation tower bypass regulating valve into the pipeline that selective oxidation tower is connected with claus reaction tower;Selective oxidation tower front pipeline is provided with a second branch pipe, and second branch pipe is further provided with oxygen supplement regulating valve group;Selective oxidation tower after the pipeline that is connected with claus reaction tower is provided with oxygen content meter, and oxygen content meter is connected with oxygen supplement regulating valve group interlock setting.The application adopts full dry method processing, no waste water discharge, can be used for H2S, COS gas desulfurization preparation sulfur containing sulfur 5% or less, temperature, concentration change, can improve sulfur yield and purity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of blast furnace gas desulfurization, in particular to a full dry method desorption gas sulfur system. BACKGROUND

[0002] The desorption gas of the blast furnace gas dry adsorption desulfurization process contains 0-2% COS and H2S, which is currently sent to sintering combustion and treated by the sintering supporting desulfurization facility. In the chemical industry, the low-concentration sulfur-containing gas with COS and H2S below 5% or the combustion returns to the front-end Claus process or uses the wet oxidation conversion sulfur paste.

[0003] In the prior art, the blast furnace and sintering process production are not completely synchronized, and the sites are far apart. The wet oxidation conversion has the disadvantages of complex process, large water consumption, high energy consumption, waste water treatment, and further purification of the obtained sulfur paste, and the direct use in blast furnace gas will increase the consumption of wet reagent due to the presence of carbon dioxide.

[0004] The temperature, moisture and sulfur content of the desorption gas of the blast furnace gas dry adsorption desulfurization process change periodically.

[0005] 1. There are two processes in the desorption temperature rising stage:

[0006] The temperature rises from 60℃ to 150℃, the moisture attached to the adsorbent is gradually separated out, the sulfur content in the desorption dirty gas is small, and as the moisture is separated out, the adsorbent temperature rising rate gradually increases, and the time is about 5 hours;

[0007] The temperature rises from 150℃ to 180℃, hydrogen sulfide is separated out at about 150℃-170℃, reaches the maximum concentration at about 160℃, and the highest concentration is about 2g / Nm3, and then carbonyl sulfur begins to be separated out, and the time is about 1-2 hours;

[0008] 2. The temperature holding stage:

[0009] The temperature is kept at 180-230℃, the separated sulfur-containing substances are mainly carbonyl sulfur, the concentration increases rapidly first and then gradually decreases, the highest concentration is about 20g / Nm3, and after 24-30h, the desorption is completely entered into the cooling process;

[0010] 3. The cooling stage:

[0011] The temperature decreases from 180℃ to 70℃, and the time is about 6-8h.

[0012] The present application develops a full dry method desorption gas sulfur system, which can treat the desorption gas of the blast furnace gas dry adsorption desulfurization process, and can also be used for preparing sulfur from other low-concentration sulfur-containing gas with COS and H2S below 5%. SUMMARY

[0013] The technical problem to be solved by the present application is to provide a full dry desorption gas sulfur system, which adopts full dry treatment, has no wastewater discharge, can be used for desulfurization of H2S and COS gas with sulfur content below 5%, temperature and concentration variation, and has sulfur yield above 95% and product sulfur purity above 98%, thereby improving the yield and purity of sulfur and preventing the plugging phenomenon caused by pure solid collection.

[0014] The present application is implemented as follows:

[0015] A full dry desorption gas sulfur system, comprising an inlet valve group, a hydrolysis tower, a temperature control device, a selective oxidation tower, a selective oxidation tower bypass regulating valve, a Claus reaction tower, a condensation crystallization system, a dust collector, an outlet valve group, a sulfur powder collection tank, a liquid sulfur seal, a liquid sulfur forming system, and a system cooling bypass valve; the inlet valve group is arranged at the front end of the hydrolysis tower, the hydrolysis tower is arranged at the front end of the temperature control device, the temperature control device is arranged at the front end of the selective oxidation tower, and the selective oxidation tower is arranged at the front end of the Claus reaction tower; a first branch pipe is arranged on the pipeline connected between the hydrolysis tower and the temperature control device, the first branch pipe is connected to the pipeline connected between the selective oxidation tower and the Claus reaction tower through the selective oxidation tower bypass regulating valve, a second branch pipe is arranged on the pipeline at the front end of the selective oxidation tower, and an oxygen supplement regulating valve group is further arranged on the second branch pipe; an oxygen content meter is arranged on the pipeline connected between the selective oxidation tower and the Claus reaction tower, and the oxygen content meter is connected in series with the oxygen supplement regulating valve group;

[0016] The outlet of the Claus reaction tower is communicated with the condensation crystallization system, an H2S and SO2 measuring device is arranged on the pipeline connected between the Claus reaction tower and the condensation crystallization system, and the H2S and SO2 measuring device is connected in series with the selective oxidation tower bypass regulating valve;

[0017] The crystallization part of the condensation crystallization system is connected with the dust collector, the sulfur powder collection tank is connected below the dust collector, and the outlet valve group is arranged at the outlet of the dust collector; the condensation part of the condensation crystallization system is connected with the liquid sulfur forming system through the liquid sulfur seal; a third branch pipe is connected to the pipeline at the front end of the inlet valve group, the third branch pipe is connected to the pipeline at the rear end of the outlet valve group through the system cooling bypass valve, a dry water drainer is further arranged on the third branch pipe, and the dry water drainer is arranged at the front end of the system cooling bypass valve.

[0018] Further, the dry water drainer can continuously drain water or intermittently drain water, and is used for draining the condensed water condensed in the pipeline from the adsorbent in the initial desorption stage when the desorption gas temperature is 100 DEG C.

[0019] Further, the temperature control device keeps the temperature in front of the selective oxidation tower between 190 DEG C and 210 DEG C.

[0020] Further, the hydrolysis tower packing loading mode is radial or axial, the hydrolysis agent is a low-temperature catalyst with one or more of alumina, silica, magnesium oxide, activated carbon as a carrier, and one or more of Fe, Mn, Cu, Zn, Co oxides and / or alkali metal carbonate as an active component.

[0021] Further, the packing loading mode of the selective oxidation tower is radial, the bed temperature gradually increases from 190 DEG C to 230 DEG C from inside to outside, the outer side of the tower body is provided with an anti-scalding heat preservation layer, heat radiating fins are arranged on the top, a safety pressure relief valve and a fire water pipe are arranged on the top, and a drain pipe is arranged on the bottom.

[0022] Further, the Claus reaction tower packing loading mode is radial or axial, the Claus packing carrier adopts a large-pore structure to reduce the adsorption of generated sulfur single substance, and the use temperature is 190-230 DEG C.

[0023] Further, the condensation crystallization system comprises a condensation part for condensing sulfur steam in coal gas to 120-130 DEG C to generate liquid sulfur, a crystallization part for further indirect quenching or direct extraction cooling to 60-80 DEG C to generate sulfur crystals, a nitrogen gas purging system, and a liquid sulfur collecting tank; the condensation crystallization system has the functions of simultaneously preparing liquid sulfur and solid sulfur, and can reduce the sulfur vapor in gas to 10 mg / Nm 3 Further, the parts in contact with liquid sulfur and sulfur powder adopt sulfur-resistant materials and are provided with anti-fouling coating.

[0024] Further, the dust collector adopts a plastic-burned plate dust collector capable of preventing dust from being agglomerated, and is provided with an intermediate ash bin and a safety pressure relief valve.

[0025] Further, the oxygen content meter and the oxygen supplement regulating valve group are connected in a chain mode, so that the oxygen content at the outlet of the selective oxidation tower is controlled to be 0.5-1%.

[0026] Further, the first branch pipe is used for supplementing H2S to the Claus reaction tower, and the H2S and SO2 measuring devices at the rear end of the Claus reaction tower are connected in a chain mode with the bypass regulating valve of the selective oxidation tower, so that the H2S:SO2 content ratio at the outlet of the Claus reaction tower is controlled to be 2-2.5:1.

[0027] The present application has the following advantages:

[0028] The present application adopts a full dry method to treat low-concentration (5% or less) sulfur-containing gas, a temperature control device is arranged at the inlet of the system, the temperature of the sulfur-containing desorbed gas can be controlled to be between 150-220 DEG C, and the subsequent reaction is facilitated.

[0029] The present application utilizes the combined arrangement of hydrolysis tower, oxidation tower and Claus reaction tower, and part of the unoxidized H2S-containing gas is mixed with the SO2-containing gas oxidized by the oxidation tower through a branch pipe into the Claus reaction tower for reaction, and the H2S and SO2 are further converted into S element; that is, COS is first hydrolyzed into H2S, and then the H2S is selectively oxidized into S element with the supplemented air, the H2S concentration in the desorption gas changes with the front end temperature of the desorption gas, the desorption time period and the amount of the supplemented air, and the oxidation process will produce part of SO2, and after the oxidation, a first Claus reaction is arranged to generate S element from the H2S before oxidation and the SO2 after oxidation, so that the S element yield can be improved, and the influence of the fluctuation of the sulfur concentration of the raw gas can be reduced;

[0030] The gas temperature from the sulfur condenser of the conventional Claus reaction system for recovering liquid sulfur is about 120 DEG C, and at this time, the saturation sulfur vapor pressure equivalent sulfur concentration on the liquid sulfur is still 700 mg / m 3 In order to recover the part of the gaseous sulfur as much as possible, the present application adopts the quenching and dust collector to collect the sulfur dust, and the sulfur dust is collected in the form of liquid sulfur and solid sulfur, and the sulfur yield is more than 95%, and the purity of the finished sulfur is more than 98%, so that the yield and purity of the S element can be improved, and the blocking phenomenon caused by the collection of the pure solid can be prevented. BRIEF DESCRIPTION OF DRAWINGS

[0031] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0032] Figure 1 is a schematic diagram of a full dry desorption gas sulfur system of the present application.

[0033] Figure 2 is a front view of a selective oxidation tower of a full dry desorption gas sulfur system of the present application.

[0034] Figure 3 is a top view of a selective oxidation tower of a full dry desorption gas sulfur system of the present application.

[0035] Figure 4 is a structure schematic diagram of a condensation crystallization system of the present application in the indirect cooling crystallization type.

[0036] Figure 5 is a structure schematic diagram of a condensation crystallization system of the present application in the direct extraction cooling crystallization type.

[0037] The numbers in the drawings are as follows:

[0038] 1, inlet valve group, 2, hydrolysis tower, 3, temperature control device, 4, selective oxidation tower, 5, Claus reaction tower, 6, condensation crystallization system, 7, dust remover, 8, outlet valve group, 9, system cooling bypass valve, 10, selective oxidation tower bypass valve, 11, H2S, SO2 measuring device, 12, oxygen supplement regulating valve group, 13 oxygen content meter, 14, liquid sulfur seal, 15, liquid sulfur forming system, 16, sulfur warehouse, 17, sulfur powder collection tank, 18, dry water trap, 19, first branch pipe, 20, second branch pipe, 21, third branch pipe;

[0039] 401, selective oxidation tower inlet center pipe, 402, selective oxidant, 403, drain pipe, 404, fire water pipe, 405, explosion relief valve, 406, selective oxidation tower outlet, 407, fin, 408, anti-scalding insulation layer;

[0040] 601, condensation crystallization system inlet, 602, bottom liquid sulfur collection tank, 603, condensation heat exchanger, 604, crystallizer dust removal nozzle, 605, crystallization heat exchanger, 606, high-temperature circulating water pump, 607, exhaust steam air cooler, 608, normal-temperature circulating water pump, 609, cooling tower, 610, wall dust removal nozzle, 611, cold extraction nozzle, 612, evaporation cooling space.

DETAILED DESCRIPTION

[0041] The technical solutions of the present application will be described below in conjunction with the accompanying drawings Figures 1-5 and specific embodiments. In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the devices or elements indicated to have a specific orientation, to be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0042] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] Please refer to Figure 1As shown, the full dry method desorbed gas system for preparing sulfur according to the present application comprises an inlet valve group 1, a hydrolysis tower 2, a temperature control device 3, a selective oxidation tower 4, a selective oxidation tower bypass regulating valve 10, a Claus reaction tower 5, a condensation crystallization system 6, a dust remover 7, an outlet valve group 8, a sulfur powder collecting tank 17, a liquid sulfur seal 14, a liquid sulfur forming system 15, a system cooling bypass valve 9, and sequentially passes through the inlet valve group 1, the hydrolysis tower 2, the temperature control device 3, the selective oxidation tower 4, the Claus reaction tower 5, the condensation crystallization system 6, the dust remover 7, and the outlet valve group 8 along the desorbed gas flow direction; the third branch pipe 21 is connected in parallel with the system cooling bypass valve 9 after the inlet valve group 1 and the outlet valve group 8.

[0044] A first branch pipe 19 is arranged on the pipeline connected with the temperature control device 3 after the hydrolysis tower 2, and the first branch pipe 19 is connected to the pipeline connected with the Claus reaction tower 5 after the selective oxidation tower bypass regulating valve 10; a second branch pipe 20 is arranged on the pipeline in front of the selective oxidation tower 4, and an oxygen supplement regulating valve group 12 is further arranged on the second branch pipe 20; an oxygen content meter 13 is arranged on the pipeline connected with the Claus reaction tower 5 after the selective oxidation tower 4, and the oxygen content meter 13 is connected in interlocking manner with the oxygen supplement regulating valve group 12.

[0045] The outlet of the Claus reaction tower 5 is communicated with the condensation crystallization system 6, and an H2S and SO2 measuring device 11 is arranged on the pipeline connected with the condensation crystallization system 6 after the Claus reaction tower 5, and the H2S and SO2 measuring device 11 is connected in interlocking manner with the selective oxidation tower bypass regulating valve 10.

[0046] The crystallization part of the condensation crystallization system 6 is connected with the dust remover 7, the sulfur powder collecting tank 17 is connected below the dust remover 7, and the outlet valve group 8 is arranged on the outlet of the dust remover 7; the condensation part of the condensation crystallization system 6 is connected with the liquid sulfur forming system 15 through the liquid sulfur seal 14; the third branch pipe 21 is connected with the pipeline in front of the inlet valve group 1, the third branch pipe 21 is connected with the pipeline at the rear end of the outlet valve group 8 through the system cooling bypass valve 9, a dry water drainer 18 is further arranged on the third branch pipe 21, and the dry water drainer 18 is arranged at the front end of the system cooling bypass valve 9. The outlet of the liquid sulfur forming system 15, the sulfur powder collecting tank 17, and a sulfur warehouse 16 are connected.

[0047] In the specific implementation, preferably, the dry water drainer 18 can continuously drain water or intermittently drain water, and is sealed reliably when there is no water and safely drains water when there is water, and is used to drain the condensed water condensed in the pipeline from the adsorbent in the initial stage of desorption when the desorbed gas temperature is 100℃.

[0048] In a specific implementation, a preferred embodiment is that the temperature control device 3 comprises a heater, a cooler, a temperature measuring point and a temperature control system, the heater uses electric heating or steam heating, the cooler uses circulating water cooling, the temperature measuring point controls the electric power or steam flow and the cooling water flow to maintain the temperature before the selective oxidation tower 4 at 190-210°C.

[0049] In a specific implementation, a preferred embodiment is that the packing in the hydrolysis tower 2 is filled in a radial or axial manner, the hydrolysis agent is a low-temperature catalyst with one or more of alumina, silica, magnesium oxide and activated carbon as a carrier and one or more of Fe, Mn, Cu, Zn and Co oxides and / or alkali metal carbonate as an active component; the hydrolysis agent has excellent temperature change resistance, when the temperature changes at a rate of 30°C / h between 100-220°C, the hydrolysis rate is above 95% and the structural strength of the hydrolysis agent does not significantly decay.

[0050] In a specific implementation, a preferred embodiment is that the packing in the selective oxidation tower 4 is filled in a radial manner, the bed temperature gradually increases from 190°C to 230°C from the inside to the outside, an anti-scalding insulation layer 408 is provided on the outside of the tower body, heat dissipation fins 407 are provided on the top for heat dissipation, a safety explosion relief valve 405 and a fire water pipe 404 are provided on the top, and a drain pipe 403 is provided at the bottom.

[0051] In a specific implementation, a preferred embodiment is that the packing in the Claus reaction tower 5 is filled in a radial or axial manner, the Claus packing carrier uses a large-pore structure to reduce the adsorption of generated elemental sulfur, and the use temperature is 190-230°C.

[0052] In a specific implementation, a preferred embodiment is that the condensation and crystallization system 6 comprises a condensation part for condensing sulfur steam in the coal gas to 120-130°C to generate liquid sulfur, a crystallization part for further indirect quenching or direct extraction cooling to 60-80°C to generate sulfur crystals, a nitrogen gas purging system and a liquid sulfur collection tank; the condensation and crystallization system has the functions of simultaneously producing liquid sulfur and solid sulfur, and can reduce the sulfur vapor in the gas to 10 mg / Nm 3 In the following, the parts in contact with liquid sulfur and sulfur powder use sulfur-resistant materials and are provided with anti-fouling coatings.

[0053] In a specific implementation, a preferred embodiment is that the dust collector 7 uses a plastic-burned plate dust collector that prevents dust from being agglomerated, and is provided with an intermediate ash bin, a safety explosion relief valve and other devices to meet the safe operation requirements of the coal gas.

[0054] In a specific implementation, a preferred embodiment is that the oxygen content meter 13 is interlocked with the oxygen supplement regulating valve group 12 to control the oxygen content at the outlet of the selective oxidation tower 4 at 0.5-1%.

[0055] In a specific implementation, a preferred embodiment is that the first branch pipe 19 is used to supply H2S to the Claus reaction tower 5, and the H2S and SO2 measuring device 11 at the rear end of the Claus reaction tower 5 is interlocked with the selective oxidation tower bypass regulating valve 10 to control the H2S:SO2 content ratio at the outlet of the Claus reaction tower 5 to be 2-2.5:1.

[0056] In an embodiment of the present application, the working process is as follows:

[0057] The moisture, temperature, and H2S content in the sulfur-containing desorbed gas change over time, and before the desorption temperature is raised to 160°C, COS and H2S are basically not generated at this time, the inlet valve group 1 is closed, the coal gas is discharged into the outlet valve group 8 pipeline through the system cooling bypass valve 9, and no sulfur is prepared; because water vapor will condense on the pipe wall at low temperature, a dry automatic water drain 18 is arranged before the system cooling bypass valve 9 to automatically drain water.

[0058] When the temperature is greater than 160°C, the system cooling bypass valve 9 is closed, and the inlet valve group 1 is opened, the desorbed gas containing COS and H2S enters the hydrolysis tower 2, and the COS is converted into H2S in the hydrolysis tower 2.

[0059] Then enter the temperature control device 3, so that the temperature of the coal gas entering the selective oxidation tower 4 is controlled between 190-210°C, and the hydrogen sulfide is converted into elemental sulfur in the selective oxidation tower 4.

[0060] Although the selective oxidation reaction is a strong exothermic process, because the hydrogen sulfide concentration in the present system process is low, the selective oxidation tower 4 adopts a reactor design with simple heat dissipation, as shown in the elevation structure of the selective oxidation tower: Figures 2-3 The selective oxidant 402 in the tower is filled in a radial manner, the coal gas enters the selective oxidant 402 from the center pipe 401 of the selective oxidation tower, and after the reaction, it enters the area surrounded by the selective oxidant 402 and the reactor wall, and is collected along the tower wall to the outlet 406 of the selective oxidation tower. There are multiple heat dissipation fins 407 on the tower wall, an explosion vent 405 and a fire water pipe 404 are arranged at the top of the tower, a fire drain pipe 403 is arranged at the bottom of the tower, and a heat protection layer 408 is arranged outside the tower wall.

[0061] The amount of oxygen / air supplement in the selective oxidation tower 4 is detected by the oxygen content meter 13, the oxygen supplement regulating valve group 12 is adjusted, and the oxygen content is controlled to be 0.5-1.0%.

[0062] The hydrogen sulfide concentration is low and the oxygen supplement / air amount is small, so the control precision is difficult to guarantee. In the process of oxygen supplement, the oxygen is excessive, and a small amount of H2S or S is inevitably over-oxidized to SO2 in the oxidation tower 4. In order to reduce the concentration of SO2 at the outlet, a bypass valve 10 of the oxidation tower is provided, which is easier to adjust. The unoxidized H2S and the byproduct SO2 generated by excessive oxidation are taken to the Claus reaction tower 5 to generate elemental sulfur by the Claus reaction, which can improve the performance of the system in resisting the fluctuation of the import sulfur concentration.

[0063] The coal gas containing gaseous elemental sulfur enters the condensation crystallization system 6 for sulfur recovery. The condensation crystallization system 6 can be an indirect cooling crystallization condensation crystallization system as shown in Figure 4 The coal gas containing gaseous elemental sulfur is cooled in two steps. In the first step, the coal gas enters the inlet 601 of the condensation crystallization system and is cooled to 125-135°C by the lower condensation heat exchanger 603. At this time, most of the gaseous sulfur is converted into liquid sulfur, which is collected in the bottom liquid sulfur collection tank 602. The remaining 500-1000 mg / Nm 3 of sulfur vapor in the gas is cooled to 60-80°C by the upper crystallization heat exchanger 605, and solid sulfur appears. The remaining gaseous sulfur content is less than 15 mg / Nm 3 A crystallizer dust removal nozzle 604 is provided between the two cooling steps to blow off the crystallization heat exchanger 605 which is easily blocked by solid sulfur.

[0064] The condensation heat exchanger 603 adopts high-temperature water-low-temperature steam closed circulation. The 80-120°C high-pressure water is pressurized by the high-temperature circulating pump 606 and sent into the condensation heat exchanger 603 to absorb the heat of the coal gas and evaporate into 0.3-0.4 MPa saturated steam. The steam is condensed into liquid water by exchanging heat with the environment air in the steam air cooler 607, and then sent into the high-temperature circulating pump 606 for recycling.

[0065] The crystallization heat exchanger 605 adopts open circulation. The 28-32°C normal-temperature water is pressurized by the normal-temperature circulating water pump 608 and sent into the crystallization heat exchanger 605 to absorb the heat of the coal gas and heat up to 38-45°C. Then the water is cooled to 28-32°C in the cooling tower 609 and then sent into the normal-temperature circulating water pump 608 for recycling.

[0066] The condensation crystallization system 6 can also be as shown in Figure 5As shown, a condensation crystallization system of direct cooling crystallization is adopted. Different from the condensation crystallization system of indirect cooling crystallization, a small amount of normal-temperature desalted water is sprayed into the second step by using the spray head 611, the heat taken away by water evaporation is used to cool the coal gas, the water spraying amount and the cross-sectional flow velocity of the coal gas in the evaporation cooling space 612 are controlled to be less than 3 m / s, the passing time is more than 4 s, the final temperature of the coal gas cooling can be controlled to be 60-80 DEG C, and no liquid water is generated. The ash removal spray head 610 arranged on the wall of the device sweeps the parts easily adhered by solid sulfur in the evaporation cooling space 612.

[0067] The liquid sulfur generated by the condensation crystallization system 6 directly enters the liquid sulfur forming system 15 through the liquid sulfur seal 14 to be made into blocky / particle / plate sulfur, and is then sent to the sulfur warehouse 16 for storage.

[0068] The solid sulfur generated by the condensation crystallization system 6 enters the dust collector 7 with the coal gas, is collected into the sulfur powder collecting tank 17, and is then sent to the sulfur warehouse 16 to be packaged into finished products.

[0069] After the coal gas passes through the dust collector 7, more than 95% of the sulfur is collected, and the remaining clean coal gas is sent to the user through the outlet valve group 8 for use.

[0070] In summary, the beneficial effects of the present application are as follows:

[0071] The present application can be used for preparing sulfur from the desorption gas of the blast furnace gas dry regeneration adsorption process or other gas containing low-concentration COS and H2S less than 5%, a temperature control device 3 is arranged in the system, the temperature of the gas entering the selective oxidation tower 4 can be controlled to be between 190-210 DEG C, which is beneficial to the subsequent reaction;

[0072] The present application utilizes the combined arrangement of the hydrolysis tower 2, the selective oxidation tower 4 and the Claus reaction tower 5, and part of the unoxidized H2S-containing gas before passing through the selective oxidation tower 4 is mixed with the SO2-containing gas oxidized by the selective oxidation tower 4 to enter the Claus reaction tower 5 to react, and H2S and SO2 are further converted into S; that is, COS is first hydrolyzed into H2S, and then H2S is selectively oxidized into S by supplementing air, part of SO2 is generated in the oxidation process due to the difficulty in controlling the H2S concentration in the desorption gas and the supplementing air amount, and after the oxidation, a first-stage Claus reaction is arranged to generate S from the H2S before oxidation and the SO2 after oxidation, which can improve the yield of sulfur and reduce the influence of the fluctuation of the sulfur concentration of the raw gas;

[0073] The conventional sulfur cooling process is complex, and when the final-stage sulfur cooling outlet temperature is 130 DEG C, the sulfur vapor in the gas is still 700 mg / m 3The system integrates a simplified sulfur cooling system and a condensation crystallization system 6 for sulfur vapor cooling crystallization to collect liquid sulfur and solid sulfur, has a sulfur yield of more than 95%, and the purity of finished sulfur is more than 98%, which can improve the yield and purity of elemental sulfur and prevent the blocking phenomenon caused by the collection of pure solid.

[0074] Although the specific embodiments of the present application are described above, those skilled in the art should understand that the specific embodiments described are only illustrative, and are not intended to limit the scope of the present application, and equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present application should be covered within the scope of the claims of the present application.

Claims

1. A fully dry desorbed gas to sulfur system, characterized by: The system comprises an import valve group, a hydrolysis tower, a temperature control device, a selective oxidation tower, a selective oxidation tower bypass regulating valve, a Claus reaction tower, a condensation crystallization system, a dust collector, an export valve group, a sulfur powder collecting tank, a liquid sulfur seal, a liquid sulfur forming system, and a system cooling bypass valve; the import valve group is arranged at the front end of the hydrolysis tower, the hydrolysis tower is arranged at the front end of the temperature control device, the temperature control device is arranged at the front end of the selective oxidation tower, and the selective oxidation tower is arranged at the front end of the Claus reaction tower; a first branch pipe is arranged on the pipeline connected between the hydrolysis tower and the temperature control device, the first branch pipe is connected to the pipeline connected between the selective oxidation tower and the Claus reaction tower through the selective oxidation tower bypass regulating valve, a second branch pipe is arranged on the pipeline at the front end of the selective oxidation tower, and an oxygen supplement regulating valve group is further arranged on the second branch pipe; an oxygen content meter is arranged on the pipeline connected between the selective oxidation tower and the Claus reaction tower, and the oxygen content meter is connected in series with the oxygen supplement regulating valve group; the outlet of the Claus reaction tower is communicated with the condensation crystallization system, an H2S and SO2 measuring device is arranged on the pipeline connected between the Claus reaction tower and the condensation crystallization system, and the H2S and SO2 measuring device is connected in series with the selective oxidation tower bypass regulating valve; the crystallization part of the condensation crystallization system is connected with the dust collector, the dust collector is connected with the sulfur powder collecting tank below, and the outlet of the dust collector is provided with an export valve group; the condensation part of the condensation crystallization system is connected with the liquid sulfur forming system through the liquid sulfur seal; a third branch pipe is connected with the pipeline at the front end of the import valve group, the third branch pipe is connected with the pipeline at the rear end of the export valve group through the system cooling bypass valve, a dry water drainer is further arranged on the third branch pipe, and the dry water drainer is arranged at the front end of the system cooling bypass valve; the selective oxidation tower is filled with radial fillings, the bed temperature gradually increases from 190℃ to 230℃ from the inside to the outside, the outer side of the tower body is provided with an anti-burn heat preservation layer, heat radiating fins are arranged on the top, a safety explosion relief valve and a fire water pipe are arranged on the top, and a drain pipe is arranged at the bottom; the dust collector adopts a plastic-burning plate dust collector capable of preventing dust from being agglomerated, and is provided with an intermediate ash bin and a safety explosion relief valve.

2. A total dry sorption gas to sulfur system as claimed in claim 1, characterized by: The dry water drainer can continuously drain water, intermittently drain water, and is used for draining the condensed water condensed in the pipeline when the desorption gas temperature is 100℃.

3. A total dry sorption gas to sulfur system as claimed in claim 1, characterized by: The temperature control device keeps the temperature at the front end of the selective oxidation tower between 190-210℃.

4. A total dry sorption gas to sulfur system as claimed in claim 1, characterized by: The fillings in the hydrolysis tower are filled in a radial or axial manner, the hydrolysis agent is a low-temperature catalyst with one or more of alumina, silica, magnesium oxide and activated carbon as a carrier, and one or more of Fe, Mn, Cu, Zn and Co oxides and / or alkali metal carbonates as active components.

5. A total dry sorption gas to sulfur system as claimed in claim 1, characterized by: The fillings in the Claus reaction tower are filled in a radial or axial manner, the Claus fillings carrier adopts a large-pore structure to reduce the adsorption of generated elemental sulfur, and the use temperature is 190-230℃.

6. A total dry sorbent gas sweetening system as claimed in claim 1, wherein: The condensing crystallization system comprises a condensing part for condensing sulfur steam in coal gas to 120-130 DEG C to produce liquid sulfur, a crystallization part for further indirect quenching or direct extraction cooling to 60-80 DEG C to produce sulfur crystals, a nitrogen gas purging system and a liquid sulfur collecting tank; the condensing crystallization system has the functions of simultaneously producing liquid sulfur and solid sulfur, and can reduce sulfur vapor in gas to 10 mg / Nm 3 In the following, the parts in contact with liquid sulfur and sulfur powder are made of sulfur-resistant materials and are provided with anti-fouling coating.

7. A total dry sorption gas to sulfur system as claimed in claim 1, wherein: The oxygen content meter is connected in series with the oxygen supplement regulating valve group, so that the oxygen content at the outlet of the selective oxidation tower is controlled to be 0.5-1%.

8. A total dry sorbent gas sweetening system as claimed in claim 1, wherein: The first branch pipe is used for supplementing H2S to the Claus reaction tower, and the H2S and SO2 measuring devices at the rear end of the Claus reaction tower are interlocked with the bypass regulating valve of the selective oxidation tower to make the H2S:SO2 content ratio at the outlet of the Claus reaction tower be 2-2.5:1.

Images