Method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing

Abstract

The invention provides a method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing, and relates to the technical field of sulfur recovery. The treatment method of the sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing comprises the following steps: mixing the sulfur-containing and oxygen-containing waste gas and hydrogenation process gas, then carrying out hydrogenation reaction, carrying out cooling, amine liquid absorption and amine liquid regeneration on the mixed gas obtained after hydrogenation reaction, obtaining purified tail gas after amine liquid absorption, and obtaining acid gas after amine liquid regeneration, the acid gas is subjected to a Claus reaction to obtain Claus tail gas, and the Claus tail gas is subjected to hydrogenation heating to obtain the hydrogenation process gas; and discharging the purified tail gas after burning. According to the method, the sulfur-containing and oxygen-containing waste gas and the heated process gas are mixed and then subjected to the catalytic reduction reaction, heat is prevented from being absorbed when hydrogenation reaction or Claus reaction is directly carried out, then the reaction temperature is reduced, the sulfur conversion efficiency is affected, energy consumption is increased, and the concentration of SO2 in the waste gas obtained through the method is lower than 200 mg / Nm < 3 >.

Description

Technical Field

[0001] The invention relates to the technical field of sulfur recovery, and in particular to a method for treating sulfur- and oxygen-containing waste gas generated by degassing liquid sulfur. Background Art

[0002] In recent years, countries around the world have increasingly stringent sulfur emission control standards. In 2015, my country issued the most stringent environmental protection regulations in the world, GB31570-2015 "Petroleum Refining Industry Pollutant Emission Standards", which stipulates that sulfur recovery devices in general areas SO 2 The emission limit is 400mg / Nm 3 , emission limit in key areas is 100mg / Nm 3 ; Subsequently, my country issued GB39728-2020 "Emission Standards for Air Pollutants from Onshore Petroleum and Natural Gas Exploitation Industry" in 2020, stipulating that natural gas purification plants with a total sulfur recovery unit capacity of more than 200t / d must 2 The emission limit is 400mg / Nm 3 The release of these environmental protection standards has put forward more stringent requirements on the sulfur recovery technology of existing sulfur recovery units.

[0003] During the production process of the sulfur recovery unit, the liquid sulfur produced from each level of sulfur condensers is collected in the liquid sulfur pool for buffering. The liquid sulfur entering the liquid sulfur pool contains 300-500μg / g of H 2 S and H 2 S X These sulfur-containing gases are toxic and harmful. They can form explosive mixtures when they gather with air in the liquid sulfur pool, which will affect the quality of sulfur products and threaten the storage, transportation and processing of liquid sulfur. Therefore, the sulfur recovery unit needs to take measures to remove H2 from the liquid sulfur. 2 S was removed to below 15 μg / g.

[0004] The existing sulfur recovery process mostly uses the method of directly discharging the sulfur-containing and oxygen-containing waste gas generated by the degassing of the liquid sulfur pool into the incinerator to burn and generate SO 2 Expel to reduce H 2 S will cause personnel poisoning risk, but will make the exhaust gas SO 2 Concentration increased by 100-300mg / Nm 3 , it is difficult to meet the increasingly stringent environmental regulations and standards.

[0005] Chinese patent CN204550054U discloses a device for degassing liquid sulfur produced by a sulfur recovery device, and the liquid sulfur degassing waste gas is sent to the Claus reactor to re-carry out the Claus reaction to achieve the recovery of sulfur elements in the waste gas. However, the liquid sulfur degassing waste gas contains inert gases such as nitrogen and steam. Entering the Claus reactor will reduce the furnace temperature, resulting in a decrease in the sulfur conversion efficiency of the Claus thermal reaction section. It is necessary to use a preheater to preheat to compensate for the temperature drop. At the same time, the Claus furnace contains a high content of hydrogen sulfide acid gas, which is easy to backflow into the negative pressure liquid sulfur pool, increasing the risk of poisoning and casualties of personnel on site in the liquid sulfur pool. Chinese patent CN105327599A discloses a method for treating liquid sulfur degassing waste gas, in which the liquid sulfur degassing waste gas is sent to the hydrogenation heating furnace of the tail gas purification unit, and the sulfur-containing and oxygen-containing waste gas is heated in the heating furnace and enters the hydrogenation reactor to generate hydrogen sulfide, and then is absorbed and regenerated by amine liquid to achieve the recovery of sulfur elements. However, when liquid sulfur waste gas with a high inert gas content enters the heating furnace, the furnace temperature will decrease, and more fuel gas and combustion air consumption must be increased to compensate for the decrease in furnace temperature, which significantly increases the energy consumption of the device. At the same time, oxygen-containing waste gas will interfere with the ratio of fuel gas and combustion air in the heating furnace, making the operation of reducing gas content control more difficult.

[0006] Therefore, there is an urgent need for a waste gas treatment method to reduce the emission of SO 2 concentration while reducing energy consumption. Summary of the invention

[0007] The purpose of the present invention is to provide a method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing, which can significantly reduce SO 2 concentration while reducing energy consumption.

[0008] To achieve the above object, the technical solution of the method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing of the present invention is:

[0009] A method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing comprises the following steps: mixing the sulfur-containing and oxygen-containing waste gas with hydrogenation process gas and then subjecting the mixed gas to hydrogenation reaction; cooling the mixed gas obtained after the hydrogenation reaction, absorbing with amine liquid and regenerating with amine liquid, obtaining purified tail gas after amine liquid absorption, and regenerating with amine liquid to obtain acidic gas; subjecting the acidic gas to Claus reaction to obtain Claus tail gas, and subjecting the Claus tail gas to hydrogenation heating to obtain the hydrogenation process gas; and discharging after incineration of the purified tail gas.

[0010] The method for treating the sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing provided by the present invention comprises the following steps: mixing the sulfur-containing and oxygen-containing waste gas with the hydrogenation process gas and then performing a hydrogenation reaction to convert the sulfur-containing compounds into hydrogen sulfide, and obtaining acidic gas by cooling, amine liquid absorption and amine liquid regeneration. The acidic gas then undergoes a Claus reaction to generate sulfur, thereby realizing the recovery of sulfur elements. The purified tail gas after amine liquid absorption is discharged by incineration, and at the same time, the sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing is prevented from directly undergoing a hydrogenation reaction or a Claus reaction to absorb heat, thereby reducing the reaction temperature and affecting the sulfur conversion efficiency, and increasing energy consumption. SO in the exhaust flue gas obtained by the treatment method provided by the present invention 2 Concentration below 200mg / Nm 3 , in line with national environmental protection standards.

[0011] In order to increase the feed amount of sulfur-containing and oxygen-containing waste gas and improve the sulfur conversion efficiency, preferably, the sulfur-containing and oxygen-containing waste gas is mixed by steam injection and then mixed with the hydrogenation process gas to carry out the hydrogenation reaction.

[0012] In order to increase the steam pressure of the sulfur-containing and oxygen-containing waste gas and improve the efficiency of the hydrogenation reaction, preferably, the steam pressure of the steam injection is 3 to 4 MPa and the flow rate is 1 to 2 t / h.

[0013] In order to further reduce heat consumption and improve sulfur conversion efficiency, preferably, the steam temperature is 240-260°C.

[0014] In order to make the process gas, Claus tail gas and sulfur-containing and oxygen-containing waste gas in a high temperature state before the hydrogenation reaction and further improve the sulfur conversion efficiency, preferably, the temperature of the hydrogenation process gas is 240-260°C.

[0015] In order to further improve the removal efficiency of steam in the sulfur-containing and oxygen-containing waste gas, preferably, the cooling temperature is 30-40°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a sulfur-containing and oxygen-containing waste gas treatment device used in Example 1 of the present invention;

[0017] Figure 2 This is a schematic diagram of a sulfur-containing and oxygen-containing waste gas treatment device of Comparative Example 1;

[0018] Figure 3 This is a schematic diagram of a sulfur-containing and oxygen-containing waste gas treatment device of Comparative Example 2;

[0019] Figure 4 This is a schematic diagram of a sulfur-containing and oxygen-containing waste gas treatment device of Comparative Example 3;

[0020] In the attached figure: 1, liquid sulfur pool; 2, sulfur-containing and oxygen-containing waste gas; 3, steam ejector; 4, thermometer; 5, medium and low pressure steam; 6, flow meter; 7, medium and low pressure steam shut-off valve; 8, sulfur-containing and oxygen-containing waste gas to hydrogenation reactor shut-off valve; 9, sulfur-containing and oxygen-containing waste gas to hydrogenation heating furnace shut-off valve; 10, hydrogenation heating furnace; 11, hydrogenation reactor; 12, hydrogenation reactor aftercooler; 13, quenching tower; 14, tail gas absorption tower; 15, regeneration tower; 16, incinerator; 17, chimney; 18, sulfur-containing and oxygen-containing waste gas to tail gas incinerator shut-off valve; 19, sulfur-containing and oxygen-containing waste gas to Claus reactor shut-off valve; 20, Claus reactor; 21, waste heat boiler; 22, primary sulfur cooler; 23, primary heater; 24, primary reactor; 25, secondary sulfur cooler; 26, secondary heater; 27, secondary reactor; 28, tertiary sulfur cooler. DETAILED DESCRIPTION

[0021] A method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing comprises the following steps: mixing the sulfur-containing and oxygen-containing waste gas with hydrogenation process gas and then subjecting the mixed gas to hydrogenation reaction; cooling the mixed gas obtained after the hydrogenation reaction, absorbing with amine liquid and regenerating with amine liquid, obtaining purified tail gas after amine liquid absorption, and regenerating with amine liquid to obtain acidic gas; subjecting the acidic gas to Claus reaction to obtain Claus tail gas, and subjecting the Claus tail gas to hydrogenation heating to obtain the hydrogenation process gas; and discharging after incineration of the purified tail gas.

[0022] In a specific embodiment, the sulfur-containing gas includes SO 2 , sulfur vapor, hydrogen sulfide, carbonyl sulfide, carbon disulfide, O 2 and nitrogen and water vapor.

[0023] In a specific embodiment, in order to further improve the reaction rate and sulfur conversion efficiency of reducing sulfur-containing and oxygen-containing waste gas to hydrogen sulfide, the catalyst used in the hydrogenation reaction includes molybdenum sulfide and cobalt sulfide. When the catalyst includes molybdenum sulfide and cobalt sulfide, both will be converted into an oxidized state under oxygen conditions and generate sulfur dioxide, and then the hydrogen sulfide in the waste gas will convert the oxidized catalyst back into a sulfide state and water, and the generated sulfur dioxide will be converted into hydrogen sulfide under the action of hydrogen. When the "speed of the reaction of hydrogen sulfide with the oxidized catalyst" far exceeds the "speed of the reaction of oxygen with the sulfide catalyst", oxygen will eventually be converted into water. This process is an exothermic reaction, and a large amount of heat is released in this process, which promotes the hydrolysis reaction of organic sulfur and then improves the sulfur recovery rate.

[0024] In a specific embodiment, the catalyst used in the catalytic reduction reaction is the oxygen-resistant low-temperature tail gas hydrogenation catalyst LSH-03G developed by the Research Institute of Sinopec Qilu Branch. The reaction equation of the catalyst LSH-03G and the sulfur-containing and oxygen-containing exhaust gas is as follows:

[0025] MoS 2+7 / 2O 2 →MoO 3 +2SO 2

[0026] Co 9 S 8 +25 / 2O 2 →9CoO+8SO 2

[0027] MoO 3 +H 2 +2H 2 S→MoS 2 +3H 2 O

[0028] 9CoO+H 2 +8H 2 S→Co 9 S 8 +9H 2 O

[0029] In a specific embodiment, the treatment device of the sulfur-containing and oxygen-containing waste gas treatment method produced by the liquid sulfur degassing method comprises a hydrogenation reactor and a cooling device, an amine liquid absorption device, an amine liquid regeneration device and an incineration device connected to the hydrogenation reactor in sequence. The outlet of the sulfur-containing and oxygen-containing waste gas suction device is connected to the inlet of the hydrogenation reactor, and the inlet of the hydrogenation reactor is also connected to the outlet of the hydrogenation heating furnace; the amine liquid regeneration device has an acid gas outlet, and the acid gas outlet of the amine liquid regeneration device is connected to the inlet of the Claus reaction device, and the Claus reaction device has a Claus tail gas outlet, and the Claus tail gas outlet is connected to the inlet of the hydrogenation heating furnace. SO in the exhaust flue gas obtained by the above-mentioned sulfur-containing and oxygen-containing treatment device 2 Concentration below 200mg / Nm 3 , in line with national environmental protection standards, the device has simple connection, is safe and effective, and has good stability.

[0030] In a specific embodiment, in order to improve the stability of the sulfur-containing and oxygen-containing exhaust gas extraction device and reduce the risk of corrosion caused by the accumulation of sulfur-containing gas in the sulfur-containing and oxygen-containing exhaust gas extraction device, the sulfur-containing and oxygen-containing exhaust gas extraction device includes a steam ejector, the steam ejector has a steam inlet, a sulfur-containing and oxygen-containing exhaust gas inlet, and a mixed gas outlet formed by steam and sulfur-containing and oxygen-containing exhaust gas, and the mixed gas outlet is connected to the inlet of the hydrogenation reactor. In order to improve the stability of the sulfur-containing and oxygen-containing exhaust gas treatment device, two parallel steam ejectors are provided, and the mixed gas outlets of the two steam ejectors are connected to the inlet of the hydrogenation reactor after merging.

[0031] In a specific embodiment, the cooling device is a hydrogenation reactor aftercooler and a cooling tower, the amine liquid absorption device is a tail gas absorption tower, the amine liquid regeneration device is a regeneration tower, the incineration device is an incinerator, and the Claus reaction device is a Claus reactor and a Claus reactor.

[0032] In a specific embodiment, the amine liquid in the amine liquid absorption device is a lean amine liquid, and the lean amine liquid absorbs the acid gas in the tail gas to make the hydrogen sulfide content below 50 ppm.

[0033] In a specific embodiment, the lean amine liquid in the amine liquid absorption device absorbs the acid gas to become a semi-rich amine liquid. The semi-rich amine liquid at the bottom of the tower is sent to the upstream to further absorb the acid gas, and then sent to the amine liquid regeneration device for regeneration. The acid gas is released and returned to the Claus reaction device for Claus reaction to recover sulfur element. The semi-rich amine liquid that releases the acid gas is regenerated into a lean amine liquid and returned to the amine liquid absorption device.

[0034] In a specific embodiment, the inert gas in the tail gas that is not absorbed by the amine liquid is incinerated through an incinerator if it can be burned, and is discharged through the incinerator if it cannot be burned.

[0035] In a specific embodiment, the functions of the hydrogenation heater are, firstly, to heat the tail gas discharged from the Claus reaction, and secondly, to provide hydrogen for the hydrogenation reactor. The Claus tail gas and hydrogen are then mixed with the sulfur-containing and oxygen-containing waste gas obtained after degassing in the liquid sulfur pool and then enter the hydrogenation reactor together.

[0036] In a specific embodiment, the hydrogen provided by the hydrogenation heater is formed by burning methane, which is burned with air to form hydrogen and carbon monoxide.

[0037] In a specific embodiment, the steam ejector uses medium-pressure steam as a power source, and two are provided, one for use and one for backup. Cut-off valves are provided at the inlet and outlet of the steam ejector. When the steam flow is too low, the exhaust gas temperature is too high, or when the downstream hydrogenation unit is shut down and the hydrogenation reactor cannot receive exhaust gas, the inlet and outlet cut-off valves of the interlock ejector are closed to prevent the exhaust gas temperature from being too high to damage the hydrogenation reactor, and the steam flow is too low to cause the gas in the hydrogenation reactor to flow back into the steam ejector, thereby protecting the entire device.

[0038] In a specific embodiment, the air in the air bubbling process is provided by a Claus blower, and the air bubbling flow rate is 150-250 kg / h. At the same time, the Claus blower provides reaction air for the Claus reactor.

[0039] The present invention is further described in detail below with reference to the embodiments.

[0040] 1. Specific embodiment of the method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing of the present invention

[0041] Example 1

[0042] The method for treating the sulfur-containing and oxygen-containing waste gas generated by degassing liquid sulfur in this embodiment is as follows: Figure 1 The sulfur-containing and oxygen-containing waste gas treatment device is used for the treatment. The method for treating the sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing in this embodiment comprises the following steps: the liquid sulfur pool 1 generates sulfur-containing and oxygen-containing waste gas 2 through the air bubbling facility laid at the bottom, and the sulfur-containing and oxygen-containing waste gas 2 is ejected to the air inlet pipeline of the hydrogenation reactor 11 through the steam ejectors 3 (one for use and one for standby), wherein the medium and low pressure steam 5 is the power source of the steam ejector, and its steam pressure is 3.5 MPa and the flow rate is 1.5 t / h.

[0043] The sulfur-containing and oxygen-containing waste gas 2 is mixed with the waste gas (260°C) from the outlet of the hydrogenation heating furnace 10 and enters the hydrogenation reactor 11 together, and undergoes a hydrogenation reaction under the action of the oxygen-resistant low-temperature hydrogenation catalyst LSH-03G, wherein the oxygen in the waste gas is converted into water, sulfur compounds such as sulfur dioxide and sulfur vapor are converted into hydrogen sulfide, and organic sulfur such as carbonyl sulfide and carbon disulfide are converted into hydrogen sulfide and carbon dioxide.

[0044] The mixed gas obtained by the hydrogenation reaction enters the hydrogenation reaction aftercooler 12 and the quench tower 13 for cooling. The gas phase outlet temperature at the top of the quench tower is 33°C. At this time, the water vapor is cooled, and other gases enter the tail gas absorption tower 14 for amine liquid absorption. The amine liquid absorbs acid gases such as hydrogen sulfide and carbon dioxide. The amine liquid flow rate at the inlet of the tail gas absorption tower is 240 t / h, and the temperature is 35°C. Then it enters the regeneration tower 15 to release the absorbed acid gases. The acid gases return to the Claus reactor 20 for Claus reaction, wherein part of the hydrogen sulfide is burned to generate sulfur dioxide, and the remaining hydrogen sulfide reacts with the generated sulfur dioxide to generate sulfur, thereby realizing the recovery of sulfur element. Other gases not absorbed by the amine liquid are purified tail gas, which is discharged from the chimney 17 after being incinerated by the incinerator 16.

[0045] The lower inlet of the Claus reactor 20 is connected to the Claus blower, which provides the combustion air of the Claus reactor. The upper inlet of the Claus reactor 20 enters the acid gas generated by the regeneration tower 15. The acid gas and the combustion air undergo a Claus reaction. At the same time, the Claus blower also provides air for the air bubbling facilities at the bottom of the degassing zones I and II in the liquid flow pool 1. The air bubbling flow rate of the liquid sulfur pool is 200 kg / h. The high-temperature Claus tail gas (above 1000°C) generated by the Claus reactor 20 is cooled to 280°C after passing through the waste heat boiler 21, and then separated from sulfur by the primary sulfur cooler 22. Then the remaining gas is heated by the heating steam of the primary reaction gas heater 23, and then the Claus reaction is carried out again in the primary reactor 24 to convert the unreacted hydrogen sulfide into sulfur. Then the gas generated by the reaction passes through the secondary sulfur cooler 25, the secondary reaction gas heater 26, the secondary reactor 27 in sequence, and finally the sulfur is separated by the tertiary sulfur cooler 28. The Claus tail gas enters the hydrogenation heating furnace 10.

[0046] The hydrogenation heating furnace 10 introduces methane gas through the upper inlet, and introduces air through the lower inlet through the fan. The methane gas and air react at high temperature to generate hydrogen and carbon monoxide to provide a hydrogen source for the subsequent hydrogenation reaction, and provide heat for hydrogen, Claus tail gas and carbon monoxide. The liquid water generated by the condensation of steam in the quenching tower 13 is extracted through the suction device arranged at the bottom of the quenching tower 13, and a part of it is discharged through the pipeline, and a part of it is cooled by the heat exchanger and enters the quenching tower 13 from the upper inlet of the quenching tower 13 as cooling water for recycling. The amine liquid in the tail gas absorption tower 14 absorbs acidic gas to become rich amine liquid, which is extracted through the suction device at the bottom of the tail gas absorption tower 14, heated by the heat exchanger, and enters from the top of the regeneration tower 15. The rich amine liquid in the regeneration tower 15 releases acidic gas, which is extracted through the suction device at the bottom of the regeneration tower 15, cooled by the heat exchanger, and enters from the top of the tail gas absorption tower 14. The purified tail gas produced by the tail gas absorption tower 14 is incinerated in the incinerator 16 and then discharged from the chimney 17 . The incinerator 16 burns the purified gas produced by the tail gas absorption tower 14 with the air blown in by the fan at the lower side and the combustion gas entering through the pipeline at the upper side.

[0047] in Figure 1 The device is 100% loaded. When the flow meter 6 shows that the steam flow is too low, the thermometer 4 shows that the temperature of the sulfur-containing and oxygen-containing exhaust gas is too high, or when the downstream hydrogenation unit is shut down and the hydrogenation reactor cannot accept the exhaust gas, the low-pressure steam shut-off valve in the steam ejector and the shut-off valve 8 for the sulfur-containing and oxygen-containing exhaust gas to the hydrogenation reactor are closed, and the entire treatment device stops working.

[0048] 2. Comparison

[0049] Comparative Example 1

[0050] The method for treating the sulfur-containing and oxygen-containing waste gas generated by degassing liquid sulfur in this comparative example is as follows: Figure 2 The sulfur-containing oxygen-containing waste gas treatment device is used for the treatment. The sulfur-containing oxygen-containing waste gas treatment method of this comparative example is to discharge the sulfur-containing oxygen-containing waste gas directly after incineration through the incinerator 16. The difference between the sulfur-containing oxygen-containing waste gas treatment method of this comparative example and that of Example 1 is that the sulfur-containing oxygen-containing waste gas 2 generated by the liquid flow pool 1 through the air bubbling facility is directly ejected to the incinerator 16 through the steam ejector 3, and then the sulfur-containing oxygen-containing waste gas is discharged from the chimney 17 after incineration, wherein the air bubbling flow rate of the liquid sulfur pool is 200kg / h, the steam pressure of the steam ejector is 0.4MPa, and the flow rate is 500kg / h.

[0051] in Figure 2 The device is at 100% load. When the flow meter 6 shows that the steam flow is too low, the thermometer 4 shows that the sulfur-containing and oxygen-containing waste gas temperature is too high, or when the downstream incinerator 16 is shut down and cannot accept waste gas, the medium and low pressure steam shut-off valve 7 and the sulfur-containing and oxygen-containing waste gas to tail gas incinerator shut-off valve 18 are closed, and the entire treatment device stops working.

[0052] Comparative Example 2

[0053] The method for treating the sulfur-containing and oxygen-containing waste gas generated by degassing liquid sulfur in this comparative example is as follows: Figure 3 The sulfur-containing oxygen-containing waste gas treatment device is used for the treatment. The sulfur-containing oxygen-containing waste gas treatment method of this comparative example is to pass the sulfur-containing oxygen-containing waste gas through a hydrogenation heating furnace and a hydrogenation reactor, and then discharge it after incineration in an incinerator. The difference between the sulfur-containing oxygen-containing waste gas treatment method of this comparative example and that of Example 1 is that the sulfur-containing oxygen-containing waste gas 2 generated by the liquid flow pool 1 through the air bubbling facility is directly ejected to the air inlet pipeline of the hydrogenation heating furnace 10 through a steam ejector 3, and then undergoes a hydrogenation reaction through a hydrogenation reactor 11, and then the gas generated by the hydrogenation reaction passes through a hydrogenation reactor aftercooler 12, a quenching tower 13, a tail gas absorption tower 14 and a regeneration tower 15, and the acid gas released from the regeneration tower returns to the Claus reactor for a Claus reaction to recover sulfur elements, and the Claus tail gas and the sulfur-containing oxygen-containing waste gas 2 are mixed and enter the hydrogenation heating furnace 10; other gases not absorbed by the amine liquid in the tail gas absorption tower 14 are purified gases, which are discharged from the chimney 17 after incineration in the incinerator 16.

[0054] in Figure 3 The device is at 100% load. When the flow meter 6 shows that the steam flow is too low, the thermometer 4 shows that the temperature of the sulfur-containing and oxygen-containing waste gas is too high, or when the downstream hydrogenation heating furnace 10 is shut down and cannot accept waste gas, the low-pressure steam shut-off valve 7 in the steam ejector and the shut-off valve 9 for the sulfur-containing and oxygen-containing waste gas to the hydrogenation heating furnace are closed, and the entire processing device stops working.

[0055] Comparative Example 3

[0056] The method for treating the sulfur-containing and oxygen-containing waste gas generated by degassing liquid sulfur in this comparative example is as follows: Figure 4 The sulfur-containing oxygen-containing waste gas treatment device is used for the treatment. The sulfur-containing oxygen-containing waste gas treatment method of this comparative example is to pass the sulfur-containing oxygen-containing waste gas through the Claus reactor first, then through the hydrogenation heating furnace and the hydrogenation reactor, and finally through the incinerator to be discharged after incineration. The difference between the sulfur-containing oxygen-containing waste gas treatment method of this comparative example and that of Example 1 is that the sulfur-containing oxygen-containing waste gas 2 generated by the liquid flow pool 1 through the air bubbling facility is directly ejected to the Claus reactor 20 through the steam ejector 3 for Claus reaction. After the Claus tail gas passes through the hydrogenation heating furnace 10, it passes through the hydrogenation reactor 11 for hydrogenation reaction, and then the gas generated by the hydrogenation reaction passes through the hydrogenation reactor aftercooler 12, the quenching tower 13, the tail gas absorption tower 14 and the regeneration tower 15. The acid gas released from the regeneration tower returns to the Claus reactor for Claus reaction to recover sulfur elements. The Claus tail gas and the sulfur-containing oxygen-containing waste gas 2 are mixed and enter the Claus reactor 20. At this time, the combustion air at the inlet of the Claus reactor needs to be preheated from 90°C to 135°C.

[0057] in Figure 4The device is at 100% load. When the flow meter 6 shows that the steam flow is too low, the thermometer 4 shows that the temperature of the sulfur-containing and oxygen-containing exhaust gas is too high, or when the downstream Claus reactor 20 is shut down and cannot receive exhaust gas, the low-pressure steam shut-off valve 7 of the steam ejector and the shut-off valve 19 for the sulfur-containing and oxygen-containing exhaust gas to the Claus reactor are closed, and the entire treatment device stops working.

[0058] 3. Experimental Examples

[0059] This experimental example is to analyze the SO in the exhaust gas after the sulfur-containing and oxygen-containing waste gas in Example 1 and Comparative Examples 1 to 3 is treated. 2 The concentration was measured and three sets of data were tested repeatedly; and the temperature changes when the sulfur-containing and oxygen-containing exhaust gases were introduced into different devices were compared to reflect the sulfur conversion efficiency of different treatment methods. The comparison results are shown in Table 1.

[0060] Table 1 SO2 discharged from different sulfur-containing and oxygen-containing waste gas treatment methods 2 Concentration and temperature changes of exhaust gas introduced at different locations

[0061]

[0062]

[0063] As can be seen from Table 1, the method for treating the sulfur-containing and oxygen-containing waste gas produced by degassing liquid sulfur provided by the present invention introduces the sulfur-containing and oxygen-containing waste gas into a hydrogenation reactor (Example 1), and the SO in the incineration tail gas is 2 Gas emission concentration is less than 200mg / Nm 3 Compared with introducing sulfur-containing and oxygen-containing waste gas into the tail gas incinerator (Comparative Example 1), SO 2 Gas emission concentration decreased by 200mg / Nm 3 , meeting the requirements of current environmental regulations.

[0064] Compared with Comparative Examples 2 and 3, although SO 2 The gas emission concentrations are similar, but directly introducing sulfur- and oxygen-containing waste gas into the hydrogenation heater and the Claus reactor will reduce the furnace temperatures of the hydrogenation heater and the Claus reactor by 20-30°C and 30-40°C respectively. The reduction in furnace temperature affects the sulfur conversion efficiency, requiring preheating or increasing the amount of fuel gas and combustion air added, increasing energy consumption, and affecting its safety, stability and operational difficulty.

Claims

1. A method for treating sulfur-containing and oxygen-containing waste gas generated by degassing liquid sulfur, characterized in that: The following steps are involved: The sulfur-containing and oxygen-containing waste gas and the hydrogenation process gas are mixed and then subjected to a hydrogenation reaction. The mixed gas obtained after the hydrogenation reaction is cooled, absorbed by amine liquid and regenerated by amine liquid. Purified tail gas is obtained after amine liquid absorption, and acid gas is obtained after amine liquid regeneration. The acid gas undergoes a Claus reaction to obtain Claus tail gas, and the Claus tail gas is heated by hydrogenation to obtain the hydrogenation process gas. The purified tail gas is discharged after incineration.

2. The method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing according to claim 1, characterized in that: The sulfur-containing and oxygen-containing waste gas is mixed with steam injection and then mixed with the hydrogenation process gas to carry out the hydrogenation reaction.

3. The method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing according to claim 2, characterized in that: The steam pressure of the steam injection is 3-4 MPa, and the flow rate is 1-2 t / h.

4. The method for treating sulfur-containing and oxygen-containing waste gas generated by liquid sulfur degassing according to claim 3, characterized in that: The steam temperature is 240-260°C.

5. The method for treating sulfur-containing and oxygen-containing waste gas generated by degassing liquid sulfur according to any one of claims 1 to 4, characterized in that: The temperature of the hydrogenation process gas is 240-260°C.

6. The method for treating sulfur-containing and oxygen-containing waste gas generated by degassing liquid sulfur according to any one of claims 1 to 4, characterized in that: The cooling temperature is 30-40°C.

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