WO2020140799A1 - 硫化氢酸性气的多级氧化制酸装置及制酸工艺 - Google Patents

硫化氢酸性气的多级氧化制酸装置及制酸工艺 Download PDF

Info

Publication number
WO2020140799A1
WO2020140799A1 PCT/CN2019/128208 CN2019128208W WO2020140799A1 WO 2020140799 A1 WO2020140799 A1 WO 2020140799A1 CN 2019128208 W CN2019128208 W CN 2019128208W WO 2020140799 A1 WO2020140799 A1 WO 2020140799A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
acid
sulfuric acid
process gas
combustion
Prior art date
Application number
PCT/CN2019/128208
Other languages
English (en)
French (fr)
Inventor
黄锐
王丹
章华勇
张媛
齐俊岭
Original Assignee
科洋环境工程（上海）有限公司
黄锐
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN201910008441.9A external-priority patent/CN109573959A/zh
Priority claimed from CN201920012748.1U external-priority patent/CN209618891U/zh
Application filed by 科洋环境工程（上海）有限公司, 黄锐 filed Critical 科洋环境工程（上海）有限公司
Publication of WO2020140799A1 publication Critical patent/WO2020140799A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B17/00—Sulfur; Compounds thereof
    • C01B17/69—Sulfur trioxide; Sulfuric acid
    • C01B17/74—Preparation
    • C01B17/76—Preparation by contact processes
    • C01B17/80—Apparatus

Definitions

  • the invention relates to a multi-stage oxidation acid production device of hydrogen sulfide acid gas and an acid production process.
  • H 2 S is one of the most common toxic and polluting substances in the chemical industry.
  • the raw materials (petroleum or coal) are in the chemical processing, conversion and refining process, and the treatment of sulfur Relevant enterprises of raw materials can produce acid gas containing H 2 S.
  • H 2 S gas is toxic, flammable and explosive, and cannot be directly discharged.
  • the synthesis gas produced by coal gasification contains H 2 S. After conversion and desulfurization and decarbonization, the H 2 S will be discharged from the device.
  • H 2 S acid gas must be strictly treated, otherwise the vented H 2 S is toxic and its Pollution of the environment, leading to long-term odors in the plant area, affecting the plant environment of the enterprise installation, and the oxidation of H 2 S to SO 2 in the air will cause acid rain, which will cause serious harm to people and the ecological environment. For this reason, oil refining units or coal chemical plants H 2 S processing device must be installed.
  • the conventional H 2 S treatment technology is mainly to convert it into sulfur.
  • H 2 S gas ⁇ (H 2 S) ⁇ 15%)
  • the Claus method is usually used to recover sulfur, but the Claus method has a low purification rate, and the exhaust gas SO 2 cannot meet the standard, and further treatment is required.
  • the technology is unstable in coal chemical plants. Not only does it have a high investment, high operating costs, but also has many technical deficiencies, such as complex processes, demanding raw materials, easy catalyst poisoning, and short continuous operation time of the device.
  • the wet oxidation method tannin extract
  • the wet oxidation method recovers sulfur.
  • the process is long, the site environment is poor, and the product sulfur quality is poor, which affects sales.
  • the gas contains other impurities, such as HCN, COS, CS 2 , tar, benzene, etc., it will affect the operation of the device or reduce the final sulfur recovery rate, and sometimes sulfur is not the product the user needs.
  • H 2 S acid production can be divided into dry contact method and wet contact method.
  • dry contact method is to incinerate H 2 S gas into SO 2 and then use a method similar to the traditional pyrite acid production process for washing, drying, catalytic conversion, and absorption.
  • the wet contact method does not require washing and drying, and converts sulfur dioxide into sulfur trioxide in the presence of water vapor and condenses directly into acid. Obviously, the wet contact process is simpler and more conducive to system heat recovery.
  • the low-temperature condensation process is a wet-contact acid production process proposed by the German Lu Qi company in the 1930s.
  • the sulfuric acid condensing device is a spray type packing tower, followed by a mist eliminator.
  • the process is as follows: acid gas containing H 2 S is combusted in an incinerator to generate SO 2 , and SO 2 is catalytically converted in the converter.
  • the gas exiting the converter directly enters the condensing tower and flows counter-currently with the circulating cold sulfuric acid sprayed at the top of the tower On contact, it condenses into acid.
  • the disadvantage of this process is that it has a limited range of application, cannot handle gases with a volume fraction of SO 2 below 3% after combustion, and is only suitable for small-scale installations.
  • Kang Kai Te process also known as high-temperature condensation process, is a modified wet contact catalytic sulfuric acid production process introduced by Luggie after the low-temperature condensation process.
  • High temperature condensation means that SO 3 gas and water vapor condense into acid at high temperature.
  • the condensing device of this process uses a venturi condenser.
  • the process is a combination of wet H 2 S gas and fuel gas, which is combusted in an incinerator to produce SO 2.
  • the SO 2 is oxidized in the converter, and the oxidized gas enters the condensed venturi tube, which is highly dispersed with hot sulfuric acid
  • sulfuric acid is generated, the heat is precipitated, and finally the gas is cooled and the sulfuric acid mist droplets are separated.
  • the process is particularly suitable for processing gases with high temperature and low content of H 2 S, CS 2 and CO 2. It can process gases with a volume fraction of SO 2 in the combustion gas as low as 1% and maintain self-heat balance.
  • the method is also suitable for processing the tail gas of the Claus recovery sulfur process, and the sulfur recovery rate can reach 99.5%.
  • the mass fraction of sulfuric acid can reach 93%.
  • the Concat process investment is relatively low, only about 30% of the Claus plant investment.
  • the Kangkaite process does not require additional energy. However, this process is only suitable for processing gases with low H 2 S, CS 2 and CO 2 content, low heat recovery rate, and slightly lower acid concentration of the product.
  • the existing three kinds of wet acid production processes generally exist when SO 3 is condensed into sulfuric acid.
  • the operation of burning silicon oil to produce condensed nodules is required.
  • the purpose of this operation is to create condensed nodules, enhance the condensation of sulfuric acid vapor, and reduce the concentration of sulfuric acid aerosol in the exhaust gas.
  • it is limited to the operator's understanding of the process and their own ability. It is difficult to control the combustion intensity of silicone oil, and it is difficult to burn to produce a suitable concentration of condensed nodules, which results in more or less condensed nodules. effect.
  • the technical problem to be solved by the present invention is to overcome the defects of the wet acid production process in the prior art that the operation is complicated, the equipment is fragile, the investment is high, and the high-concentration and low-concentration hydrogen sulfide acid gas cannot be processed at the same time, and provides A multi-stage oxidation acid production device of hydrogen sulfide acid gas and acid production process.
  • the process provided by the invention can process high-concentration and low-concentration hydrogen sulfide acid gas at the same time, and greatly reduces the equipment investment and operation cost.
  • the invention provides a multi-stage oxidation acid production device of hydrogen sulfide acid gas.
  • the multi-stage oxidation acid production device includes a H 2 S combustion device, a combined reactor connected to the H 2 S combustion device, A sulfuric acid steam condenser and an acid mist trap;
  • the H 2 S combustion device is used to combust hydrogen sulfide acid gas to generate SO 2 process gas, and the combined reactor is used to catalytically oxidize the SO 2 process gas to generate SO 3 process gas.
  • the internal structure of the combined reactor There are several catalyst beds and inter-segment heat exchangers distributed between two adjacent catalyst beds;
  • the sulfuric acid steam condenser is used to condense the SO 3 process gas to form sulfuric acid.
  • the sulfuric acid steam condenser includes a shell, an exhaust gas outlet is provided at the top of the shell, and an input SO is provided at the bottom of the shell 3
  • the gas inlet of the process gas is also provided with a liquid discharge port below the air inlet, and a number of glass tubes for circulating cooling medium are provided in the housing along the long axis direction of the housing.
  • the glass tubes are spanned between the two side walls of the housing, the end of the glass tube located upstream of the cooling medium is the leading end, and the end located downstream of the cooling medium is the trailing end, upstream and downstream of the cooling medium
  • the adjacent adjacent glass tubes are connected end to end to form at least one unidirectional cooling medium flow channel;
  • the acid mist trap is connected to the sulfuric acid vapor condenser, and the connection is provided on the casing between the air inlet and the exhaust gas discharge port, and is used for trapping and removing entrained sulfuric acid aerosol.
  • the H 2 S combustion device has a burner, the burner has a central channel and an annular channel ring-shaped outside the central channel, the central channel is used to pass H 2 S acidic The mixed gas of air and air, the annular channel is used for fuel gas.
  • the acid gas co-firing technology that is, a specially designed burner, pulses acid gas and air to be burned at the central hole, and the fuel gas is supplemented by the burner ring system to increase combustion, which improves the stability of acid gas combustion.
  • This design solves The H 2 S concentration in the acid gas fluctuates greatly, ensuring a stable reaction under low concentration (4%-15% mol) H 2 S conditions.
  • the burner has fast load adjustment speed, strong adaptability and high gasification efficiency.
  • the H 2 S combustion device is preferably a combustion furnace, and a secondary cyclone is provided in the furnace chamber.
  • the combustion furnace is also directly connected to a downstream waste heat boiler, and the gas outlet of the waste heat boiler is also connected to the top of the combined reactor. That is, the burned hot process gas directly enters the inlet pipe side of the waste heat boiler through the combustion furnace, and enters the combined reactor from the top after cooling.
  • the combustion furnace is directly connected to the downstream waste heat boiler, using direct heat exchange technology, high heat recovery efficiency, and overcomes the defects of equipment easy to scale and block.
  • the inter-segment heat exchangers are distributed between two adjacent catalyst beds in sequence. From top to bottom, it is denoted as the first catalyst bed, the first interstage heat exchanger, the second catalyst bed, the second interstage heat exchanger, and the third catalyst bed.
  • the catalyst bed is filled with a catalyst, the upper part of each catalyst bed is provided with a manhole, and the lower part is provided with a catalyst discharge port. Under the action of a catalyst, SO 2 is converted into SO 3 by catalytic oxidation, and excessive combustion air in the combustion reaction section helps to increase the SO 2 reaction equilibrium conversion rate.
  • the combined reactor has a compact structure, saves costs, optimizes space layout, is convenient for manufacturing and maintenance, and is beneficial to thermal energy gradient recycling and is scientific and reasonable.
  • the bottom of the inter-stage heat exchanger and the shell part are fixed by channel steel beams; the top of the inter-stage heat exchanger and the shell part are connected by a conical shell, and the connection method is a sliding connection to ensure the free expansion and contraction of the inter-stage heat exchanger;
  • the connecting pipe connecting the heat exchanger and the shell should have sufficient length to maintain a certain flexibility to prevent excessive local stress on the shell.
  • the process gas enters from the upper inlet of the combined reactor and enters the first catalyst bed. After the gas passes through the catalyst bed, partial conversion is completed, and the hot gas after the reaction passes through the grid plate at the bottom of the bed.
  • Lay double-layer wire mesh of 10*10mm-wire diameter ⁇ 2mm, H 75mm ⁇ 25mm ceramic ball, 3*3mm-wire diameter ⁇ 1mm double-layer wire mesh in order to prevent the catalyst from falling into the next layer of space .
  • the process gas passes through the grid plate and enters the first inter-stage heat exchanger through the cone shell; the inter-stage heat exchanger adopts a serpentine tube structure and is supported by three support plates in the middle.
  • the heat exchange tube and the support plate No welding, keep sliding connection; the outside of the heat exchange tube is sealed with stainless steel plate to prevent process gas from passing through the gap between the heat exchange tube and the support plate.
  • the process gas passes through the second catalyst bed, the second interstage heat exchanger, and the third catalyst bed, and then flows out from the lower outlet of the combined reactor.
  • a process gas cooler is preferably provided at the bottom of the combined reactor.
  • the unidirectional cooling medium channel formed by the glass tube can withstand high temperature and strong corrosion, avoid equipment deformation and corrosion damage in high temperature and strong corrosive environments, and ensure The condenser is used for a long time to improve the safety and fluency of the condenser.
  • a fiber filter plate is also preferably provided on the top of the sulfuric acid steam condenser.
  • the acid mist trap is preferably a high-speed fiber mist eliminator. Through the physical trapping method of high-efficiency fiber demister, the high-efficiency treatment of acid mist is achieved. The defogging efficiency is ⁇ 95% and the pressure drop is small ( ⁇ 1.0KPa), which does not affect the exhaust emissions.
  • the high-speed fiber demister preferably uses a high-strength fiber splitting wire wrapped PTFE filter mesh, woven into a layered filter, when the process gas containing sulfuric acid droplets (acid mist) passes through the filter, through Forced interception to achieve efficient capture of acid mist and sulfuric acid aerosol entrained in it, and then the exhaust gas is discharged to the chimney to be emptied, with a filtration accuracy of 99.99% ( ⁇ 0.5um).
  • the process of the present invention cancels the operation of the technology imported from abroad to burn silicone oil to produce condensed nodules, and the high-efficiency fiber mist eliminator physical trapping method also achieves efficient treatment of acid mist.
  • the acid mist control adopts multi-level precision forced interception, and directly controls the outlet acid mist ⁇ 10ppm under any working conditions.
  • the purpose of this operation is to enhance the condensation of sulfuric acid vapor and reduce the concentration of sulfuric acid aerosol in the exhaust gas
  • the removal of sulfuric acid mist entrained in the gas can achieve a high sulfuric acid acid mist capture rate.
  • the exhaust gas is basically free of acid mist. Even if there is a trace of acid mist, it can ensure that the acid mist in the exhaust gas meets the standard emission.
  • the liquid discharge port is also connected to a sulfuric acid mixing tank.
  • the axis of the cylinder extends in the direction of the long axis of the shell, and the surface formed by the cylinder turning around the axis is the side. wall.
  • both the head end and the tail end of the glass tube may be located inside the housing, and at this time, the head and tail ends of the glass tube are connected by an adapted glass pipe.
  • the shape of the formed cooling medium flow channel is not limited, and it may be a “bow” shape, a “Z” shape, or other shapes.
  • the upward and downward flow direction design can further improve the fluidity of the cooling medium, increase the medium flow rate, and then improve the condensation efficiency.
  • the liquid outlet of the acid mist trap is also connected to the sulfuric acid mixing tank.
  • the tail gas outlet of the acid mist trap is also connected to a tail gas scrubbing tower, and trace amounts of SO 2 in the tail gas scrubbing tower are washed by H 2 O 2 dilute solution and are removed by H 2 O 2 Direct oxidation to SO 3 , formation of sulfuric acid droplets, and the final exhaust emission.
  • the invention also provides a multi-stage oxidation acid production process of hydrogen sulfide acid gas, which is carried out by using the multi-stage oxidation acid production unit as described above, which includes the following steps: firstly burning H 2 S acid gas to produce SO 2 process Gas, and then catalytically oxidize the SO 2 process gas to produce SO 3 process gas, and then condense into sulfuric acid; the concentration of H 2 S in H 2 S acid gas is ⁇ 0.5%mol, and the molar concentration is the mole of H 2 S The amount is a percentage of the molar amount of H 2 S acid gas.
  • the process of the present invention has a wide operating range, and is suitable for high concentration and low concentration H 2 S working conditions of coal chemical industry. It accepts H 2 S acid gas with a concentration as low as 0.5% mol (preferably above 1% mol). Low concentration (4%-15%mol) H 2 S can also be stable combustion, but the traditional wet sulfuric acid process can not be stable combustion under low concentration conditions, this process overcomes the problem of low concentration can not be stable combustion, at the same time, high concentrations (e.g. 20-30% mol) of the acid gas can be stably combusted in the combustor, for example, in a preferred embodiment of the present invention, the acid gas H 2 S in an amount of 29.16% mol. It should be noted that when the concentration of H 2 S in the acid gas is less than 0.5% mol, it is not necessary to use this process for removal, and it can be directly discharged into the atmosphere.
  • the process of the present invention can process various sulfur-containing gases, which can come from low-temperature methanol washing, hot regenerated acid gas, water gas expansion gas, stripped acid gas, phenol recovery acid gas, etc.
  • Various forms of sulfide undergo multi-stage oxidation, and finally recovered into commercial grade concentrated sulfuric acid.
  • the H 2 S acid gas may be an acid waste gas containing H 2 S common in the chemical industry. Because it is a wet acid production process, there is not much requirement for the moisture content of the raw material gas, that is, it can accept a process gas with a relatively high moisture content.
  • the process of the present invention also has very broad requirements on the treatment flow rate and operation flexibility.
  • the flow rate of the H 2 S acid gas is 2000 Nm 3 /h.
  • the process operation flexibility is large, for example, 30%-110% operation flexibility can be achieved, and the minimum 10% load operation limit is acceptable (the load here is for the feed gas flow rate), adapting to the wide range fluctuations of the feed gas flow rate and sulfide concentration.
  • the acid gas combustion section is introduced as follows:
  • H 2 S in acid gas is combustible with a flash point of 600°C.
  • H 2 S can react with oxygen in the air and maintain a stable thermal combustion reaction.
  • the reaction is as follows:
  • the combustion reaction speed is fast, H 2 S can be completely converted into SO 2 in a short time, and heat is released at the same time.
  • the combustion reaction temperature depends on the H 2 S concentration, C n H m concentration in the acid gas, and the combustion air distribution ratio.
  • the H 2 S acid gas from the boundary zone is sent to the H 2 S combustion device, and the hot air after heat exchange through the sulfuric acid vapor condenser is pre-mixed by the burner to burn in the H 2 S combustion device
  • Thermal reactions specific reactions include the above reaction formulas (1) to (3).
  • the combustion temperature of H 2 S acid gas is generally 800 to 1200° C. This temperature depends on the concentration of H 2 S in the acid gas, the amount of air distribution for combustion, and the split ratio of hot air.
  • H 2 S acid gas H 2 S in use peroxygen combustion combustion air ratio for a stoichiometric amount of preferably 1.2 to 2.2 times, more preferably 2.1 times, i.e. combustion of H 2 S
  • combustion air ratio for a stoichiometric amount of preferably 1.2 to 2.2 times, more preferably 2.1 times, i.e. combustion of H 2 S
  • the concept of air distribution ratio refers to the ratio of the molar amount of air added to the acid gas to the molar amount of pure H 2 S.
  • Peroxygen combustion is conducive to promoting the full reaction of various impurities in the acid gas (hydrocarbon, alcohol, ammonia, hydrocyanic acid, etc.), and these impurities often cause the problem of unstable operation of the device and the problem of product quality degradation.
  • the reaction residence time of H 2 S acid gas in the H 2 S combustion device is ⁇ 1.5s.
  • the SO 2 obtained by H 2 S combustion is converted into SO 3 catalytically, and the reaction (4) is a chemical equilibrium reaction.
  • this step is carried out in stages, between levels The reaction heat is removed through the inter-stage cooler, the reaction temperature of the process gas is lowered, and the reaction equilibrium conversion rate is increased while taking into account the reaction speed.
  • the temperature of the process gas cooled by the waste heat boiler is generally 410°C to 430°C, such as 420°C.
  • the introduction of waste heat boilers and the connection between the combustion furnace and the waste heat boiler can reduce the heat loss of the combustion furnace by 0.2Gcal/h, or slightly lower.
  • the inter-segment heat exchangers are distributed between two adjacent catalyst beds in sequence, preferably
  • the process gas inlet temperature of the first catalyst bed is controlled above 380°C; the process gas inlet temperature of the second catalyst bed is controlled below 410°C; the process gas inlet temperature of the third catalyst bed Control below 390°C.
  • the hot process gas enters the first catalyst bed of the combined reactor at 420°C from the top, the temperature after the reaction is increased to 510°C, and then passes through the heat exchanger between the first stage and the device After heat exchange of the produced steam, the temperature was lowered to 410°C, and it was fed into the second catalyst bed of the reactor. After the reaction, the temperature rose to 418°C, and then decreased to 385 after the heat exchange between the heat exchanger and the steam produced by the device °C, and finally enter the third catalyst bed of the reactor.
  • the final gas temperature is about 381 °C, and the temperature is reduced to 280 °C by the process gas cooler, and then sent to the sulfuric acid vapor condenser in the downstream process.
  • the temperature of the process gas leaving the process gas cooler is higher than the dew point temperature to prevent corrosion of the sulfuric acid vapor in the downstream process and cause corrosion of the equipment. Thermal shock strength to coating materials and quartz glass heat exchange tubes.
  • the cooling medium is generally cold air.
  • H 2 O 2 solution is also introduced during the condensation process for oxidizing the trace SO 2 entrained in the SO 3 process gas to SO 3 , and then condensing to form sulfuric acid droplets.
  • H 2 O 2 provided exhaust potent oxide units, i.e., trace amounts of SO 2 is washed by dilute H 2 O 2 solution, H 2 O 2 by direct oxidation of SO 3, sulfuric acid to form droplets, and then through the mist trap Collection, so that the ultra-low emission of exhaust gas can be achieved, the exhaust gas SO 2 can be ⁇ 50mg/Nm 3 , and the ultra-low emission can be achieved, which can meet the current industry's technical expectations of environmental protection and zero emissions.
  • the H 2 O produced by the H 2 S combustion reaction (Reaction 1) will react with the SO 3 obtained by catalytic conversion as follows:
  • the sulfuric acid steam will be cooled and condensed in the sulfuric acid steam condenser, and the heat of reaction will be released at the same time:
  • the water content in the SO 3 process gas is preferably 9.96%.
  • the inlet temperature of the SO 3 process gas into the sulfuric acid steam condenser is preferably 285-295°C, and more preferably 290-295°C.
  • the hot air temperature at the outlet of the sulfuric acid steam condenser is preferably maintained at about 180°C.
  • the higher the temperature of the hot air at the outlet the smaller the cooling air volume, which can reduce the load of the cooling fan, and the more conducive to energy saving and consumption reduction of the device.
  • the outlet temperature is too high to exceed the allowable temperature of the top cover anti-corrosion paint and other equipment, the equipment will be damaged and the gains will not be paid out.
  • the SO 3 process gas enters a sulfuric acid steam condenser, where the temperature is further reduced to promote the condensation of sulfuric acid steam into sulfuric acid.
  • the SO 3 process gas enters the sulfuric acid steam condenser and flows from bottom to top along the shell side.
  • the air sent in the tube side exchanges heat as the cold medium and the hot process gas to reduce the temperature of the hot process gas to 93°C. With the decrease of the temperature of the hot process gas, sulfuric acid vapor gradually condenses on the glass heat exchange tube and then forms droplets , Dropped by gravity on the bottom of the sulfuric acid steam condenser.
  • the air is boosted by a primary fan and sent to the sulfuric acid steam condenser, and enters the top of the tube box.
  • the tube box is divided into two sides, which are divided into multiple sections by internal partitions. After entering the air tube box, the air is transverse to the internal partition of the tube box Enter the glass heat exchange tube, flush the glass tube, and exchange heat with the heat process gas. After exiting the glass heat exchange tube, collect at the other end of the air tube box, and then continue to enter the next section in the tube box, in this way to form an S-shaped flow.
  • Cross-flow heat exchange with process gas the temperature of the final air leaving the sulfuric acid steam condenser is about 180 °C.
  • the temperature of sulfuric acid sent from the bottom of the sulfuric acid steam condenser is about 252°C.
  • the outlet exhaust gas temperature of the sulfuric acid steam condenser is controlled below 93°C; the difference between the air pressure and the exhaust gas pressure is controlled at 3Kpa.
  • the temperature of the concentrated sulfuric acid produced by the condensation of sulfuric acid vapor is relatively high.
  • cold sulfuric acid is mixed and quenched, and the temperature is reduced to 40°C by heat exchange, and then sent out of the boundary zone.
  • the hot air sent out of the sulfuric acid vapor condenser is partly increased in pressure through the secondary fan, and sent to the combustion furnace at the front of the device as combustion air, and the remaining air is sent to the chimney to empty to increase the exhaust gas exhaust. Temperature and lift.
  • the above reactions (1) to (6) are all exothermic reactions.
  • the device uses external boiler water to produce saturated steam in the boundary area, and the subsequent steam superheating method removes the reaction heat of each section of the reaction to maintain the device thermal balance, and at the same time Produce high-quality steam.
  • the reagents and raw materials used in the present invention are commercially available.
  • the positive effect of the present invention is characterized in progress: multi-stage oxidation and acid acid production apparatus of the present invention provides an acidic hydrogen sulphide gas, after which a combustion, H 2 S acid gas H 2 S in the total conversion of 99.9 More than %; in the catalytic oxidation process, the SO 2 conversion rate is more than 99.5%.
  • the sulfur recovery rate of the process is as high as 99.8%, and the concentration of SO 2 tail gas emissions is below 100mg/Nm 3 , which is far lower than the new national standard GB16297-2013 requiring less than 400mg/Nm 3 ; the concentration of sulfuric acid products produced can reach 97 -98wt%, no impurities, clear and transparent color, the quality meets the national GB534-2014 premium product standard.
  • the invention improves the convenience of operation, the stability of the equipment and the amount and concentration range of acid gas used.
  • the invention has simple process operation, stable equipment and low investment; compared with the low-temperature condensation process and the Kangkaite process, there is no restriction on the use concentration range of the raw material gas, and low concentration and high concentration H 2 S can be processed at the same time Sour gas, accept H 2 S acid gas as low as 0.5% mol.
  • the device of the present invention has a self-heat balance, no external heat supply, no need for pure oxygen, no fuel gas consumption, and a high degree of exhaust gas purification, which can achieve emission compliance.
  • FIG. 1 is a process flow diagram of a multi-stage oxidation acid production device according to Embodiment 1 of the present invention.
  • FIG. 2 is a schematic structural diagram of a sulfuric acid vapor condenser according to Embodiment 1 of the present invention.
  • the multi-stage oxidation acid production device for hydrogen sulfide acid gas provided in this embodiment is shown in FIG. 1.
  • the multi-stage oxidation acid production device includes a combustion furnace 4 and a combined reactor 5 connected to the combustion furnace 4.
  • Sulfuric acid steam condenser 1 (as shown in FIG. 2) and an acid mist trap 6.
  • the combustion furnace 4 is used to combust hydrogen sulfide acid gas to generate SO 2 process gas, and the combined reactor 5 is used to catalytically oxidize the SO 2 process gas to generate SO 3 process gas.
  • the burner 4 has a burner with a central channel and an annular channel ring-shaped outside the central channel.
  • the central channel is used for introducing the mixed gas of H 2 S acid gas and air
  • the annular channel is used for introducing fuel. gas.
  • acid gas co-firing technology that is, a specially designed burner
  • the acid gas and air are pulsed into the central hole for combustion, and the fuel gas is supplemented by the burner ring system to supplement the combustion, which improves the stability of acid gas combustion.
  • This design solves The H 2 S concentration in the acid gas fluctuates greatly, ensuring a stable reaction under low concentration (4%-15% mol) H 2 S conditions.
  • the burner has fast load adjustment speed, strong adaptability and high gasification efficiency.
  • the combustion furnace 4 is also directly connected to a downstream waste heat boiler 401, and the gas outlet of the waste heat boiler 401 is also connected to the top of the combined reactor 5. That is, the burned hot process gas directly enters the inlet pipe side of the waste heat boiler 401 through the combustion furnace 4, and enters the combined reactor 5 from the top after cooling.
  • the combustion furnace 4 is directly connected to the downstream waste heat boiler 401, adopts direct heat exchange technology, and has high heat recovery efficiency, and overcomes the defects that the equipment is prone to scaling and clogging.
  • the combined reactor 5 is provided with three catalyst beds and two inter-stage heat exchangers: denoted as the first catalyst bed 501, the second catalyst bed 503, and the third catalyst bed, respectively
  • the inter-segment heat exchangers are sequentially distributed between two adjacent catalyst beds, and are respectively referred to as a first inter-segment heat exchanger 502 and a second inter-segment heat exchanger 504.
  • the first catalyst bed layer 501, the second catalyst bed layer 503, and the third catalyst bed layer 505 are filled with catalyst.
  • the upper part of the bed is provided with a manhole, and the lower part is provided with a catalyst discharge port.
  • the combined reactor 5 has a compact structure, saves cost, optimizes space layout, is convenient for manufacturing and maintenance, and is beneficial to thermal energy gradient recovery and utilization, and is scientific and reasonable.
  • the bottom section of the first-stage heat exchanger 502 and the second section of the heat exchanger 504 are fixed with channel steel beams at the bottom and the shell part; the top and the shell part are connected by a conical shell, and the connection method is a sliding connection to ensure the first section
  • the free expansion and contraction of the inter-stage heat exchanger 502 and the second inter-stage heat exchanger 504; the connecting pipe between the first inter-stage heat exchanger 502 and the second inter-stage heat exchanger 504 and the shell should have a sufficient length to maintain a certain Flexibility to prevent excessive local stress on the housing.
  • the process gas enters from the upper inlet of the combined reactor 5 and enters the first catalyst bed 501. After the gas passes through the first catalyst bed 501, partial conversion is completed, and the hot gas after the reaction passes through the grid plate at the lower part of the bed.
  • Lay double-layer wire mesh of 10*10mm-wire diameter ⁇ 2mm, H 75mm ⁇ 25mm ceramic ball, 3*3mm-wire diameter ⁇ 1mm double-layer wire mesh in order to prevent the catalyst from falling into the next layer of space .
  • the process gas passes through the grid plate and enters the first interstage heat exchanger 502 through the cone shell; the first interstage heat exchanger 502 and the second interstage heat exchanger 504 adopt a serpentine tube structure with three support plates in the middle Support, in order to ensure free expansion and contraction, the heat exchange tube and the support plate are not welded, and maintain a sliding connection; the exterior of the heat exchange tube is sealed with a stainless steel plate to prevent process gas from passing through the gap between the heat exchange tube and the support plate.
  • the process gas passes through the second catalyst bed 503, the second inter-stage heat exchanger 504, and the third catalyst bed 505.
  • the bottom of the combined reactor 5 is also provided with a process gas cooler 506. After the process gas cooler 506 is cooled, it then flows out from the lower outlet of the combined reactor 5.
  • the sulfuric acid steam condenser 1 is used to condense the SO 3 process gas to form sulfuric acid; the acid mist trap 6 is connected to the sulfuric acid steam condenser 1, and the connection is located between the inlet 12 and the tail gas discharge 11 of the sulfuric acid steam condenser 1 , Used to trap the sulfuric acid aerosol that is carried out.
  • the sulfuric acid vapor condenser 1 in this embodiment includes a vertically-arranged rectangular shell with a tail gas discharge port 11 at the top and an input SO 3 process at the bottom of the shell Air inlet 12. There is also a drain 13 below the air inlet 12 for discharging concentrated sulfuric acid after condensation.
  • the bottom of the casing is in a semi-circular structure, and the liquid discharge port 13 is located at the bottom of the semi-circular structure.
  • the bottom of the housing may be other structures that gradually shrink in the liquid discharge direction, such as an inverted triangle or an inverted trapezoid.
  • a fiber filter plate 3 as a filtering mechanism is provided on the top of the casing upstream of the exhaust gas discharge port 11 for filtering small liquid particles in the exhaust gas generated after condensation.
  • Twelve glass tubes are vertically provided between the left and right side walls of the housing along the long axis direction (ie, the vertical direction in FIG. 2 ), and both ends of all glass tubes extend to the outside of the housing.
  • the two adjacent glass tubes between the upstream and the downstream of the flow direction of the cooling air as the cooling medium, that is, the two adjacent glass tubes in Fig. 2 are connected in sequence head-to-tail and end-to-end. Forming a cooling medium flow path from top to bottom, unidirectional flow.
  • two adjacent glass tubes are connected by a U-shaped rubber hose 23.
  • the cooling medium flow channel includes a cooling medium inlet located at the upper part of the casing and a cooling medium outlet located at the lower part of the casing. Cold air enters from the cooling medium inlet and flows along the cooling medium flow passage to the cooling medium outlet to be discharged.
  • the cooling medium inlet is the first end of the glass tube 21, and the cooling medium outlet is the rear end of the glass tube 22.
  • the unidirectional cooling medium channel formed by the glass tube can withstand high temperature and strong corrosion, and avoid equipment deformation and corrosion damage in high temperature and strong corrosive environments. It ensures long-term use of the condenser and improves the safety and fluency of the sulfuric acid vapor condenser 1.
  • the acid mist trap 6 is a high-speed fiber demister.
  • the high-speed fiber demister adopts a high-strength fiber split wire wrapped PTFE filter mesh, woven into a layered filter.
  • the purpose of this operation is to enhance sulfuric acid vapor condensation and reduce the concentration of sulfuric acid aerosol in the exhaust gas ), to remove the sulfuric acid mist entrained in the gas, can achieve a high sulfuric acid acid mist capture rate, the exhaust gas is basically free of acid mist, even if there is a trace of acid mist ( ⁇ 10ppm), it can ensure that the acid mist in the exhaust gas meets the standard emission.
  • the discharge port 13 of the sulfuric acid vapor condenser 1 is also connected to a sulfuric acid mixing tank 7.
  • the casing of the sulfuric acid vapor condenser 1 is a cylinder
  • the axis extension direction of the cylinder is the long axis direction of the casing
  • the surface formed by the rotation of the cylinder around the axis is The described side walls.
  • both the head end and the tail end of the glass tube may be located inside the housing, and at this time, the head and tail ends of the glass tube are connected by an adapted glass pipe.
  • the shape of the formed cooling medium flow channel is not limited, and it may be a “bow” shape, a “Z” shape, or other shapes.
  • the cooling medium is generally cold air.
  • the cooling medium is air
  • the upward and downward flow direction design can further improve the fluidity of the cooling medium, increase the flow rate of the medium, and then improve the condensation efficiency.
  • liquid outlet of the acid mist trap 6 is also connected to the sulfuric acid mixing tank 7.
  • the acid production process in this embodiment includes the following steps:
  • the combustion furnace 4 adopts two-stage combustion, that is, setting a secondary cyclone in the furnace chamber is equivalent to setting secondary forced mixing, which can greatly improve the combustion intensity.
  • the burned process gas undergoes multi-stage oxidation, so that the SO 2 process gas is catalytically oxidized to form SO 3 .
  • the unidirectional cooling medium channel formed by the glass tube can withstand high temperature and strong corrosion, avoid equipment deformation and corrosion damage in high temperature and strong corrosive environment, ensure the long-term use of sulfuric acid vapor condenser 1, improve sulfuric acid The use safety and smoothness of the steam condenser 1.
  • the acid mist control adopts multi-level precision forced interception method, directly controlling the outlet acid mist ⁇ 10ppm.
  • the tail gas outlet of the acid mist trap 6 is also connected to a tail gas scrubber 8, the tail gas is provided with a H 2 O 2 powerful oxidation unit, and the SO 2 in the tail gas of the device can be reduced to ⁇ 70 mg/Nm 3 the amount of SO 2 is washed by dilute H 2 O 2 solution, H 2 O 2 by direct oxidation of SO 3, sulfuric acid droplets are formed and then collected by the mist trap and condensed to give 60% wt sulfuric acid incorporated In the product, the ultra-low emission of the exhaust gas is realized in this way, and the exhaust gas SO 2 can be ⁇ 50mg/Nm 3 to achieve the ultra-low emission, which can meet the current industry's technical expectations of environmental protection and zero emissions.
  • the device can process H 2 S equivalent of 20.4 tons/day, and can produce sulfuric acid (98 wt%) equivalent of 63 tons/day. 125.7 tons of superheated steam (420°C, 4.0 MPa).
  • step (1) the combustion temperature of the acid gas is 903.7°C.
  • the proportion of combustion air is 2.1 times.
  • the residence time of H 2 S acid gas in the combustion furnace is 1.5s.
  • the temperature of the process gas cooled by the waste heat boiler 401 is 420°C.
  • step (2) the hot process gas enters the first catalyst bed 501 of the combined reactor 5 from the top at 420°C.
  • the temperature is increased to 510°C, and then passes through the After heat exchange of steam production, the temperature was lowered to 410°C, and it was sent to the second catalyst bed 503 of the reactor.
  • the temperature rose to 418°C.
  • the process gas cooler 506 the temperature is reduced to 280°C, and it is sent to the sulfuric acid vapor condenser 1 in the downstream process.
  • the water content in the SO 3 process gas discharged from step (2) is 9.96%.
  • the inlet temperature of the SO 3 process gas into the sulfuric acid steam condenser 1 is 290-295°C.
  • the hot air temperature at the outlet of the sulfuric acid steam condenser 1 is maintained at about 180°C.
  • the SO 3 process gas enters the sulfuric acid steam condenser 1 to further reduce the temperature and promote the condensation of sulfuric acid steam into sulfuric acid.
  • the SO 3 process gas enters the sulfuric acid steam condenser 1 and flows from bottom to top along the shell side.
  • the air sent in the tube side exchanges heat as the cold medium and the hot process gas to reduce the temperature of the hot process gas to 93°C. With the decrease of the temperature of the hot process gas, sulfuric acid vapor gradually condenses on the glass heat exchange tube and then forms droplets , Dropped by gravity on the bottom of the sulfuric acid vapor condenser 1.
  • the air is boosted by a primary fan and sent to the sulfuric acid steam condenser 1, and enters the top of the tube box.
  • the tube box is divided into left and right ends, which are divided into multiple sections by internal partitions.
  • the air moves along the internal partition of the tube box Transversely enter the glass heat exchange tube, flush the glass tube, and exchange heat with the heat process gas.
  • the temperature of the air leaving the sulfuric acid steam condenser 1 is about 180 °C.
  • the temperature of sulfuric acid sent from the bottom of sulfuric acid steam condenser 1 is about 252°C.
  • the temperature of the exhaust gas at the outlet of the sulfuric acid steam condenser 1 is controlled below 93°C; the difference between the air pressure and the exhaust gas pressure is controlled at 3Kpa.
  • the temperature of the concentrated sulfuric acid generated by the condensation of sulfuric acid vapor is relatively high, and cold sulfuric acid mixed quenching and heat exchange are used to reduce the temperature to 40°C, and then sent out of the boundary area.
  • the hot air from the sulfuric acid vapor condenser 1 is sent partly through a secondary fan to increase the pressure, and then sent to the combustion furnace at the front of the device as combustion air. The remaining air is sent to the chimney to empty to increase the temperature and lift of the exhaust gas.
  • the device exhaust emissions are as follows:
  • the process flow diagram of the multi-stage oxidation acid plant of this embodiment and the sulfuric acid steam condenser are shown in Figures 1-2.
  • the flow rate is 34328Nm 3 /h, H 2 S concentration: 1% mol as acidic raw material Gas, it can produce sulfuric acid (93wt%) equivalent 142 tons/day, superheated steam (420°C, 4.0MPa) 350.4 tons/day.
  • step (1) the combustion temperature of the acid gas is 896°C.
  • the proportion of combustion air is 2.1 times.
  • the residence time of H 2 S acid gas in the combustion furnace is 1.5s.
  • the temperature of the process gas cooled by the waste heat boiler 401 is 420°C.
  • step (2) the hot process gas enters the first catalyst bed 501 of the combined reactor 5 from the top at 420°C.
  • the temperature is increased to 510°C, and then passes through the After heat exchange of steam production, the temperature was lowered to 410°C, and it was sent to the second catalyst bed 503 of the reactor.
  • the temperature rose to 418°C.
  • the process gas cooler 506 the temperature is reduced to 280°C, and it is sent to the sulfuric acid vapor condenser 1 in the downstream process.
  • the water content in the SO 3 process gas discharged from step (2) is 9.96%.
  • the inlet temperature of the SO 3 process gas into the sulfuric acid steam condenser 1 is 290-295°C.
  • the hot air temperature at the outlet of the sulfuric acid steam condenser 1 is maintained at about 180°C.
  • the SO 3 process gas enters the sulfuric acid steam condenser 1 to further reduce the temperature and promote the condensation of sulfuric acid steam into sulfuric acid.
  • the SO 3 process gas enters the sulfuric acid steam condenser 1 and flows from bottom to top along the shell side.
  • the air sent in the tube side exchanges heat as the cold medium and the hot process gas to reduce the temperature of the hot process gas to 93°C. With the decrease of the temperature of the hot process gas, sulfuric acid vapor gradually condenses on the glass heat exchange tube and then forms droplets , Dropped by gravity on the bottom of the sulfuric acid vapor condenser 1.
  • the air is boosted by a primary fan and sent to the sulfuric acid steam condenser 1, and enters the top of the tube box.
  • the tube box is divided into left and right ends, which are divided into multiple sections by internal partitions.
  • the air moves along the internal partition of the tube box Transversely enter the glass heat exchange tube, flush the glass tube, and exchange heat with the heat process gas.
  • the temperature of the air leaving the sulfuric acid steam condenser 1 is about 180 °C.
  • the temperature of sulfuric acid sent from the bottom of sulfuric acid steam condenser 1 is about 252°C.
  • the temperature of the exhaust gas at the outlet of the sulfuric acid steam condenser 1 is controlled below 93°C; the difference between the air pressure and the exhaust gas pressure is controlled at 3Kpa.
  • the temperature of the concentrated sulfuric acid generated by the condensation of sulfuric acid vapor is relatively high, and cold sulfuric acid mixed quenching and heat exchange are used to reduce the temperature to 40°C, and then sent out of the boundary area.
  • the hot air from the sulfuric acid vapor condenser 1 is sent partly through a secondary fan to increase the pressure, and then sent to the combustion furnace at the front of the device as combustion air. The remaining air is sent to the chimney to empty to increase the temperature and lift of the exhaust gas.
  • the device exhaust emissions are as follows:

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)

Abstract

提供一种硫化氢酸性气的多级氧化制酸装置及制酸工艺。该装置包括一H 2S燃烧装置（4）、一与H 2S燃烧装置相连的组合式反应器（5）、一硫酸蒸汽冷凝器（1）和一酸雾捕集器（6）；H 2S燃烧装置用于将硫化氢酸性气燃烧生成SO 2工艺气，组合式反应器用于将SO 2工艺气催化氧化生成SO 3工艺气，组合式反应器的内部设有若干个催化剂床层（501，503，505）和分布于相邻两个催化剂床层之间的段间换热器（502，504）；硫酸蒸汽冷凝器用于将SO 3工艺气冷凝形成硫酸；酸雾捕集器与硫酸蒸汽冷凝器连接，连接处位于硫酸蒸汽冷凝器的进气口与尾气排放口之间。该工艺能同时处理高浓度和低浓度的硫化氢酸性气，且能大幅降低装置投资及操作成本。

Description

硫化氢酸性气的多级氧化制酸装置及制酸工艺
本申请要求申请日为2019年1月4的CN2019100084419以及申请日为2019年1月4日的中国专利申请CN2019200127481的优先权。本申请引用上述中国专利申请的全文。
技术领域
本发明涉及一种硫化氢酸性气的多级氧化制酸装置及制酸工艺。
背景技术
H 2S是化工行业最常见的毒性物质和污染物质之一，在煤化工、石油化工、钢铁冶炼等行业中，原料(石油或煤炭)在化学加工、转化和提炼过程中，以及处理含硫原料的有关企业，都能产生含H 2S的酸性气。H 2S气体有毒，且易燃易爆，不能直接排放。而煤气化产生的合成气中含有H 2S，经过变换和脱硫脱碳后，H 2S将排放出装置，该H 2S酸性气必须严格处理，否则放空的H 2S具有毒性，且其污染环境，导致厂区长期恶臭味道，影响企业装置的厂区环境，同时H 2S在空气中被氧化为SO 2会造成酸雨，对人及生态环境造成严重的危害，为此炼油装置或煤化工装置必须设置H 2S处理装置。
但常规采用的H 2S处理技术主要是将其转化为硫磺。对于高浓度H 2S气体ψ((H 2S)≥15％)，通常用克劳斯法回收硫磺，但克劳斯法净化率低，尾气SO 2不能达标，需要进一步处理，同时克劳斯技术在煤化工装置中运行不稳定，其不仅投资高，运行成本高，并且存在着诸多技术方面的缺陷，例如工艺复杂，原料要求苛刻、催化剂易中毒、装置连续运行时间短。对于低浓度H 2S气体，往往用湿式氧化法(栲胶)回收硫磺，而湿式氧化法回收硫磺，流程长，现场环境差，且产品硫磺质量较差，影响销路。此外，如果气体中含有其他杂质，如HCN、COS、CS 2、焦油、苯等，会影响装置的操作或降低最终硫回收率，况且有时硫磺并不是用户所需要的产品。
在这些情况下用H 2S气体生产硫酸将是一种很有吸引力的选择。用H 2S生产硫酸可省去很多工艺过程，降低投资和生产成本，使产品具有更强的市场竞争力。根据二氧化硫催化转化的工艺条件，H 2S制酸可分为干接触法和湿接触法。所谓的干接触法是将H 2S气体焚烧成SO 2后，采用与传统的硫铁矿制酸工艺相似的方法洗涤、干燥、催化转化、吸收。湿接触法则是无需洗涤、干燥，在水蒸汽存在下将二氧化硫催化转化成三氧化硫并直接凝结成酸。显而易见，湿接触法工艺更为简单，更有利于***热量的回收利用。由于大多数H 2S气源都比较干净，所以湿接触法制酸工艺的应用也较为广泛。一般认为，SO 2+SO 3质量分数为0.3％-7％的条件下，湿法制酸工艺是一种最为经济的选择。目前最 有代表性的技术为丹麦托普索公司的湿法硫酸工艺(Wet gas Sulphuric Acid，缩写WSA)、德国鲁奇公司的低温冷凝工艺和康开特(Concat)工艺。
国外的WSA技术，该工艺是将酸性气中的各种硫化物转化为浓硫酸，采用的冷凝装置为降膜式冷凝器。工艺过程为：酸性气燃烧生成SO 2，转化成SO 2含湿气体经冷却进入SO 2转化器生成SO 3，SO 3和携带的水蒸气进入冷凝器直接冷凝成酸。其以硫酸作为最终产品，其技术可靠，但操作复杂，设备易损，投资也较高。
低温冷凝工艺是20世纪30年代德国鲁奇公司提出的一种湿接触法制酸工艺。该工艺中硫酸冷凝装置是喷淋式填料塔，其后接除雾器。该工艺过程是：含H 2S的酸性气体在焚烧炉内燃烧生成SO 2，SO 2在转化器内催化转化，出转化器的气体直接进入冷凝塔，与塔顶喷淋的循环冷硫酸逆流接触，冷凝成酸。该工艺缺点是使用范围有限，不能处理燃烧后体积分数SO 2低于3％的气体，仅适用于小规模装置。
康开特工艺又称高温冷凝工艺，是鲁奇公司继低温冷凝工艺后又推出的改良的湿法接触催化生产硫酸工艺。高温冷凝即SO 3气体与水蒸气在高温下凝结成酸。该工艺的冷凝装置选用文丘里管冷凝器。该工艺过程为湿的H 2S气体与燃料气配合，在焚烧炉内进行燃烧生成SO 2，SO 2在转化器内进行氧化，氧化后的气体进入冷凝文丘里管，与高度分散的热硫酸并流接触，生成硫酸，沉析放热，最后进行气体的冷却和硫酸雾滴的分离。该工艺特别适用于处理温度高，H 2S，CS 2和CO 2含量低的气体，可处理燃烧气中SO 2体积分数低至1％的气体并保持自热平衡。该法也适用于处理克劳斯法回收硫工艺的尾气，硫回收率可达99.5％。产品硫酸的质量分数可达到93％。与克劳斯排放气脱硫工艺相比较，康开特工艺的投资比较低，约只有克劳斯装置投资的30％。此外，康开特工艺除风机和循环泵需电力外，不需要附加其他能量。但该工艺只适合处理H 2S，CS 2和CO 2含量低的气体，热量回收率低，产品酸浓度稍低。
现有的三种湿法制酸工艺普遍存在SO 3冷凝成硫酸时，需要设置燃烧硅油制造凝结核的操作，该操作目的是创造凝结核，增强硫酸蒸汽冷凝，降低尾气中硫酸气溶胶浓度。但实际操作中，限于操作人员对工艺的理解和自身能力，对硅油燃烧强度难以掌控，很难燃烧产生合适浓度的凝结核，导致凝结核偏多或偏少，这样都无法正确得到硫酸冷凝的效果。
随着国家对环保方面的日益重视，以及越来越严格的尾气排放标准，使得迫切需要一种能同时处理高浓度和低浓度的硫化氢酸性气、投资成本低、操作简单、尾气排放达标的硫回收技术。
发明内容
本发明所要解决的技术问题在于克服现有技术中的湿法制酸工艺存在的操作复杂，设备易损，投资高，以及无法同时处理高浓度和低浓度的硫化氢酸性气的缺陷，而提供了一种硫化氢酸性气的多级氧化制酸装置及制酸工艺。本发明提供的工艺能同时处理高浓度和低浓度的硫化氢酸性气，且大幅降低了装置投资及操作成本。
本发明提供了一种硫化氢酸性气的多级氧化制酸装置，所述多级氧化制酸装置包括一H 2S燃烧装置、一与所述H 2S燃烧装置相连的组合式反应器、一硫酸蒸汽冷凝器和一酸雾捕集器；
所述H 2S燃烧装置用于将硫化氢酸性气燃烧生成SO 2工艺气，所述组合式反应器用于将SO 2工艺气催化氧化生成SO 3工艺气，所述组合式反应器的内部设有若干个催化剂床层和分布于相邻两个所述催化剂床层之间的段间换热器；
所述硫酸蒸汽冷凝器用于将SO 3工艺气冷凝形成硫酸，所述硫酸蒸汽冷凝器包括一壳体，所述壳体的顶部设有一尾气排放口，在所述壳体的底部具有一个输入SO 3工艺气的进气口，在所述进气口的下方还设有一排液口，在所述壳体内沿所述壳体的长轴方向设有用于流通冷却介质的若干玻璃管，所述玻璃管均跨设于所述壳体的两侧壁之间，所述玻璃管位于该冷却介质上游的一端为首端，位于该冷却介质下游的一端为尾端，在该冷却介质的上游和下游之间相邻的所述玻璃管首尾相连通从而形成至少一条单向导流的冷却介质流道；
所述酸雾捕集器与所述硫酸蒸汽冷凝器连接，连接处设于所述进气口与所述尾气排放口之间的壳体上，用于捕集脱出夹带的硫酸气溶胶。
较佳地，所述H 2S燃烧装置具有一烧嘴，所述烧嘴具有一中心通道和环设在所述中心通道外的一环形通道，所述中心通道用于通入H 2S酸性气与空气的混合气体，所述环形通道用于通入燃料气。采用酸性气共烧技术，即特殊设计的烧嘴，在其中心孔脉冲送入酸性气与空气燃烧，同时燃料气通过烧嘴环系补充燃烧，提高了酸性气燃烧的稳定性，该设计解决了酸性气中H 2S浓度波动大，保障在低浓度(4％-15％mol)H 2S工况下的稳定反应。烧嘴负荷调节速度快，适应能力强，气化效率高。
本发明中，所述H 2S燃烧装置较佳地为一燃烧炉，其炉膛内设置有二次旋流器。
其中，所述的燃烧炉较佳地还与一下游的废热锅炉直接连接，所述废热锅炉的气体出口还与所述组合式反应器的顶部连接。即燃烧后的热工艺气通过燃烧炉直接进入所述废热锅炉的入口管程，经降温后从顶部进入所述组合式反应器。燃烧炉与下游废热锅炉直接连接，采用直接换热技术，热回收效率高，克服了设备易结垢和堵塞的缺陷。
较佳地，所述组合式反应器的内部设有3个催化剂床层和2个段间换热器，所述段 间换热器依次分布于相邻两个所述催化剂床层之间。从上到下记为第一催化剂床层、第一段间换热器、第二催化剂床层、第二段间换热器和第三催化剂床层。所述催化剂床层装填有催化剂，每个催化剂床层的上部设人孔，下部设催化剂卸料口。在催化剂作用下，SO 2催化氧化转化为SO 3，燃烧反应段过量的助燃空气有助于提高SO 2的反应平衡转化率。该组合式反应器结构紧凑，节约成本，优化空间布置，便于制造检修，而且有利于热能梯度回收利用，科学合理。
段间换热器底部与壳体部分采用槽钢梁进行固定；段间换热器顶部与壳体部分采用锥壳进行连接，连接方式采用滑动连接，保证段间换热器的自由伸缩；段间换热器与壳体相连的接管应有足够的长度，保持一定的挠性，防止对壳体产生过大的局部应力。
其中，工艺气体由组合式反应器上部的入口进入，进入第一催化剂床层。气体通过催化剂床层后，完成部分转化，反应后的热气体通过床层下部的格栅板。格栅板上方依次铺设10*10mm-丝径Φ2mm的双层丝网，H＝75mm的Φ25毫米瓷球，3*3mm-丝径Φ1mm的双层丝网，防止催化剂破损落入下一层空间。工艺气穿过格栅板，通过锥壳进入第一段间换热器；段间换热器采用蛇形管结构，中间采用三块支持板支撑，为保证自由伸缩，换热管与支持板不焊，保持滑动连接；换热管的外部用不锈钢板密封，防止工艺气通过换热管与支持板之间的空隙。依次类推，工艺气依次通过第二催化剂床层，第二段间换热器，第三催化剂床层后，从组合式反应器的下出口流出。
其中，所述组合式反应器的底部较佳地还设有一工艺气冷却器。
本发明所述的硫酸蒸汽冷凝器中，由玻璃管形成的单向导流的冷却介质通道能够耐受高温和强腐蚀，避免在高温和强腐蚀性环境中发生设备变形和腐蚀损毁现象，确保了冷凝器长时间使用，提高冷凝器的使用安全性和流畅性。
所述硫酸蒸汽冷凝器的顶部较佳地还设有一纤维滤板。所述酸雾捕集器较佳地为一高速纤维除雾器。通过高效纤维除雾器物理捕集的方法，实现对酸雾的高效处理，除雾效率≥95％，压降小(≤1.0KPa)，不影响尾气排放。所述高速纤维除雾器较佳地采用高强度的纤维劈裂丝包裹PTFE的过滤网，编织为层状过滤器，当含有硫酸液滴(酸雾)的工艺气通过该过滤器时，通过强制拦截，实现对酸雾和其中夹带的硫酸气溶胶的高效捕集，而后尾气排至烟囱放空，过滤精度可达99.99％(≥0.5um)。
本发明的工艺取消了国外引进技术燃烧硅油制造凝结核的操作，通过高效纤维除雾器物理捕集的方法，同样实现对酸雾的高效处理。酸雾控制采用多级精密强制拦截方式，在任何工况下直接控制出口酸雾≤10ppm。
其中，通过内设的纤维滤板与外置的高速纤维除雾器配合(替代了国外引进技术燃 烧硅油制造凝结核的操作，该操作目的是增强硫酸蒸汽冷凝，降低尾气中硫酸气溶胶浓度)，除去气体中夹带的硫酸雾沫，可以达到较高的硫酸酸雾捕集率，放空尾气中基本不含酸雾，即使有微量酸雾，也能保证尾气中酸雾达标排放。
本发明中，较佳地，所述硫酸蒸汽冷凝器中，所述排液口还与一硫酸混合罐连接。
需要说明的是，当上述壳体为一圆柱体时，该圆柱体的轴线延伸方向即为所述壳体的长轴方向，而圆柱体绕该轴线回旋所形成的表面则为所述的侧壁。
另外，所述玻璃管的首端和尾端可均位于所述壳体内部，此时所述玻璃管的首、尾通过适配的玻璃管道连接。在此对所形成的冷却介质流道的形状不做限制，其可以为“弓”字型、“Z”字型或者其他形状。
所述硫酸蒸汽冷凝器中，当冷却介质为空气时，为配合冷空气下降的特性，上进下出的流向设计能进一步提高冷却介质的流动性，提高介质流速，继而提高冷凝效率。
本发明中，较佳地，所述酸雾捕集器的液体出口也与所述硫酸混合罐连接。
本发明中，较佳地，所述酸雾捕集器的尾气出口还与一尾气洗涤塔连接，在尾气洗涤塔中痕量的SO 2通过H 2O 2稀溶液的洗涤，被H 2O 2直接氧化为SO 3，形成硫酸液滴，最终的尾气达标排放。
本发明还提供了一种硫化氢酸性气的多级氧化制酸工艺，其采用如上所述的多级氧化制酸装置进行，其包括如下步骤：先将H 2S酸性气燃烧生成SO 2工艺气，再将SO 2工艺气催化氧化生成SO 3工艺气，然后冷凝成硫酸即可；H 2S酸性气中H 2S的浓度为≥0.5％mol，所述摩尔浓度为H 2S的摩尔量占H 2S酸性气的摩尔量的百分比。
本发明的工艺操作范围广，同时适用于煤化工高浓度和低浓度H 2S工况，接受低至0.5％mol浓度的H 2S酸性气(较佳地为1％mol以上)，另外在低浓度(4％-15％mol)H 2S工况下也能稳定燃烧，而传统的湿法硫酸工艺中低浓度工况下不能稳定燃烧，本工艺克服了低浓度不能稳定燃烧的问题，同时，高浓度(例如20-30％mol)的酸性气在燃烧器也可以稳定燃烧，例如在本发明一较佳实施方式中，酸性气中H 2S含量为29.16％mol。需要说明的是，当酸性气中H 2S的浓度小于0.5％mol时，就无需采用本工艺进行脱除了，而可以直接排放到大气。
从原料气来源来讲，本发明的工艺可以处理各种含硫气体，可以来自于低温甲醇洗、热再生的酸性气、水煤气膨胀气、汽提酸性气、酚回收酸性气等，并把各种形式的硫化物进行多级氧化，最终回收成商品级的浓硫酸。即，所述的H 2S酸性气可以为化工领域常见的含H 2S的酸性废气。因为是湿法制酸工艺，对原料气中的水分含量也没有太大要求，也就是说可以接受水分含量相当高的工艺气。
另外，本发明的工艺对处理流量和操作弹性的要求也很宽泛，例如在某具体实施方式中，所述的H 2S酸性气的流量为2000Nm 3/h。工艺操作弹性大，例如可做到30％-110％的操作弹性，可接受最低10％负荷操作下限(这里的负荷是针对原料气流量)，适应原料气流量和硫化物浓度的大范围波动。
本发明的工艺中，酸性气燃烧段的介绍如下：
酸性气中H 2S是可燃物，闪点为600℃，当温度和酸气浓度达到一定数值时，H 2S可与空气中的氧反应，并保持稳定的热燃烧反应，反应如下：
Figure PCTCN2019128208-appb-000001
该燃烧反应速度快，短时间内H 2S能够全部转化为SO 2，同时放出热量。
若酸性气还包括微量的CH 3OH和烃类物质(C nH m)，将同时发生以下反应：
Figure PCTCN2019128208-appb-000002
C nH m+(n+m/4)O 2→m/2H 2O+n CO 2+反应热     (3)
燃烧反应温度决定于酸性气中H 2S浓度、C nH m浓度、以及燃烧配风比。
较佳地，来自界区处的H 2S酸性气，送至H 2S燃烧装置，与通过硫酸蒸汽冷凝器换热后的热空气经燃烧器预混后在H 2S燃烧装置中发生燃烧热反应，具体反应包括上述反应式(1)～(3)。
其中，H 2S酸性气的燃烧温度一般为800～1200℃，该温度取决于酸性气中H 2S浓度、燃烧的配风量及热空气的分流比。
本发明的工艺使用宽松的硫氧比控制，无须精确控制H 2S/O 2比例，操作简便。其中，较佳地，H 2S酸性气中H 2S采用过氧燃烧，助燃空气配比量较佳地为化学当量的1.2～2.2倍，更佳地为2.1倍，也就是H 2S燃烧配风比的概念(H 2S/空气)，配风比是指酸性气中加入的空气的摩尔量与纯的H 2S的摩尔量之比。过氧燃烧有利于促进酸性气中各种杂质的充分反应(烃、醇、氨、氢氰酸等)，而这些杂质往往会造成装置运行不稳定问题，以及产品品质下降的问题。
本发明中，较佳地，H 2S酸性气在H 2S燃烧装置内的反应停留时间≥1.5s。
本发明的工艺中，SO 2催化转化段的介绍如下：
Figure PCTCN2019128208-appb-000003
上述燃烧反应中，由H 2S燃烧得到的SO 2催化转化为SO 3，反应(4)为化学平衡反应，考虑到反应速率和平衡转化率等因素，该步骤反应分级进行，各级之间通过段间冷 却器移出反应热，降低工艺气的反应温度，兼顾反应速度的同时提高反应平衡转化率。
其中，较佳地，当燃烧炉和组合式反应器之间还设有一废热锅炉时，经所述废热锅炉冷却后的工艺气温度一般为410℃～430℃，例如420℃。另外，废热锅炉的引入，以及燃烧炉与废热锅炉的连接方式，可以使燃烧炉的热损失减少0.2Gcal/h，或者略低一点。
当所述组合式反应器的内部设有3个催化剂床层和2个段间换热器，所述段间换热器依次分布于相邻两个所述催化剂床层之间时，较佳地，所述第一催化剂床层的工艺气进口温度控制在380℃以上；所述第二催化剂床层的工艺气进口温度控制在410℃以下；所述第三催化剂床层的工艺气进口温度控制在390℃以下。
在本发明一较佳实施方式中，热工艺气以420℃从顶部进入组合式反应器的第一催化剂床层，反应后温度提高至510℃，后在第一段间换热器通过与装置所产蒸汽热量交换后降温至410℃，送入反应器第二催化剂床层，反应后温度升至418℃，后在第二段间换热器通过与装置所产蒸汽热量交换后降至385℃，最后进入反应器第三催化剂床层，反应后最终气体温度约为381℃，经工艺气冷却器降温至280℃，送入下游工艺中的硫酸蒸汽冷凝器。离开工艺气冷却器的工艺气温度高于露点温度，以防止在下游工艺中硫酸蒸汽冷凝沉积造成设备腐蚀，同时有利于保护下游硫酸蒸汽冷凝器内涂层，同时保护石英玻璃换热管，降低对涂层材料及石英玻璃换热管的热冲击强度。
所述硫酸蒸汽冷凝器中，所述的冷却介质一般为冷空气。
本发明中，较佳地，在冷凝过程中还通入H 2O 2溶液，用于将SO 3工艺气中夹带的痕量的SO 2氧化为SO 3，再经冷凝形成硫酸液滴。尾气设置H 2O 2强效氧化单元，即痕量的SO 2通过H 2O 2稀溶液的洗涤，被H 2O 2直接氧化为SO 3，形成硫酸液滴，进而通过酸雾捕集器收集，如此实现尾气的超低排放，尾气SO 2可≤50mg/Nm 3，实现超低排放，可满足当前行业对环保的零排放的技术期望。
本发明的工艺中，SO 3转化和H 2SO 4蒸汽冷凝的介绍如下：
H 2S燃烧反应(反应1)所产生的H 2O将与催化转化得到的SO 3发生以下反应：
SO 3(g)+H 2O(g)→H 2SO 4(g)+反应热       (5)
继而硫酸蒸汽将在硫酸蒸汽冷凝器中降温冷凝，同时放出反应热：
H 2SO 4(g)→H 2SO 4(L)+反应热        (6)
本发明中，SO 3工艺气中水含量较佳地为9.96％。本发明中，SO 3工艺气进入硫酸蒸汽冷凝器的入口温度较佳地为285～295℃，更佳地为290～295℃。
本发明中，硫酸蒸汽冷凝器的出口热风温度较佳地保持在180℃左右。出口热风温度越高，冷却风量越小，可以降低冷风机的负荷，越有利于装置的节能降耗。但出口温度若 太高超过顶盖防腐涂料和其他设备容许的温度，将会损坏设备，得不偿失。
在本发明一较佳实施方式中，SO 3工艺气进入硫酸蒸汽冷凝器，在该冷凝器内进一步降低温度，促使硫酸蒸汽冷凝成硫酸。SO 3工艺气进入硫酸蒸汽冷凝器，沿壳程由下向上流动。管程内送入的空气作为冷介质与热过程气交换热量而降低热过程气的温度至93℃，伴随热过程气温度降低，硫酸蒸汽逐步冷凝于玻璃换热管上，后结成液滴，靠重力滴落在硫酸蒸汽冷凝器的底部。空气由一次风机提压后送至硫酸蒸汽冷凝器，进入管箱的顶部，管箱分左右两端，分别通过内部隔板分割为多段，空气进入空气管箱后沿管箱内部的隔板横向进入玻璃换热管，冲刷玻璃管，与热过程气热量交换，出玻璃换热管后在空气管箱的另外一端汇集，然后继续进入管箱中的下一段，以此方式形成S型流，与过程气错流换热，最终离开硫酸蒸汽冷凝器的空气温度约为180℃。硫酸蒸汽冷凝器底部送出的硫酸温度约为252℃。
本发明中，较佳地，所述硫酸蒸汽冷凝器的出口尾气温度控制在93℃以下；空气与尾气压差控制在3Kpa。
本发明中，由硫酸蒸汽冷凝产生的浓硫酸温度较高，较佳地，还采取冷硫酸混合急冷以及换热降温至40℃，后送出界区。
在高温条件下，部分SO 3将水合反应生成H 2SO 4蒸汽，随温度降低，水合反应的程度将右移，反应参考上述反应式(5)和反应式(6)。
在本发明一较佳实施方式中，送出硫酸蒸汽冷凝器的热空气，部分经二次风机提高压力，送至装置前段的燃烧炉作为助燃空气，剩余的空气送烟囱放空，以提高放空尾气的温度及升力。
以上反应(1)～(6)均为放热反应，装置利用外供锅炉水在界区内生产饱和蒸汽，以及后续蒸汽过热的方式移走各段反应的反应热，保持装置热平衡，同时副产高品质蒸汽。
在符合本领域常识的基础上，上述各优选条件，可任意组合，即得本发明各较佳实例。
本发明所用试剂和原料均市售可得。
本发明的积极进步效果在于：本发明提供的硫化氢酸性气的多级氧化制酸装置及制酸工艺，其中经一级燃烧后，H 2S酸性气中H 2S总转化率可达99.9％以上；催化氧化过程中，SO 2转化率在99.5％以上。总体而言，工艺的硫回收率高达99.8％，SO 2尾气排放浓度为100mg/Nm 3以下，远低于国家GB16297-2013要求小于400mg/Nm 3的新标准；生产的硫酸产品浓度可达到97-98wt％，不含杂质，色度清澈透明，品质达到国家GB534-2014 优等品标准。
本发明提高了操作的便利性，设备的稳定性以及酸性气的使用气量及浓度范围。本发明相比WSA技术，工艺操作简单，设备稳定，投资较低；相比低温冷凝工艺和康开特工艺，没有原料气的使用浓度范围限制，可以同时处理低浓度和高浓度的H 2S酸性气，接受低至0.5％mol浓度的H 2S酸气。
另外本发明的装置自热平衡，无须外供热量，不需使用纯氧，也无燃料气消耗且尾气净化度高，能够达标排放。
附图说明
图1为本发明实施例1的多级氧化制酸装置的工艺流程图。
图2为本发明实施例1的硫酸蒸汽冷凝器的结构示意图。
图1中，附图标记说明如下：
硫酸蒸汽冷凝器 1
燃烧炉 4
废热锅炉 401
组合式反应器 5
第一催化剂床层 501
第一段间换热器 502
第二催化剂床层 503
第二段间换热器 504
第三催化剂床层 505
工艺气冷却器 506
酸雾捕集器 6
硫酸混合罐 7
尾气洗涤塔 8
图2中，附图标记说明如下：
硫酸蒸汽冷凝器 1
尾气排放口 11
进气口 12
排液口 13
玻璃管 21
玻璃管 22
U型橡皮软管 23
纤维滤板 3
具体实施方式
下面通过实施例的方式进一步说明本发明，但并不因此将本发明限制在所述的实施例范围之中。下列实施例中未注明具体条件的实验方法，按照常规方法和条件，或按照商品说明书选择。
实施例1
本实施例提供的硫化氢酸性气的多级氧化制酸装置如图1所示，所述多级氧化制酸装置包括一燃烧炉4、一与燃烧炉4相连的组合式反应器5、一硫酸蒸汽冷凝器1(如图2所示)和一酸雾捕集器6。
燃烧炉4用于将硫化氢酸性气燃烧生成SO 2工艺气，组合式反应器5用于将SO 2工艺气催化氧化生成SO 3工艺气。
燃烧炉4具有一烧嘴，烧嘴具有一中心通道和环设在中心通道外的一环形通道，中心通道用于通入H 2S酸性气与空气的混合气体，环形通道用于通入燃料气。采用酸性气共烧技术，即特殊设计的烧嘴，在其中心孔脉冲送入酸性气与空气燃烧，同时燃料气通过烧嘴环系补充燃烧，提高了酸性气燃烧的稳定性，该设计解决了酸性气中H 2S浓度波动大，保障在低浓度(4％-15％mol)H 2S工况下的稳定反应。烧嘴负荷调节速度快，适应能力强，气化效率高。
其中，燃烧炉4还与一下游的废热锅炉401直接连接，废热锅炉401的气体出口还与组合式反应器5的顶部连接。即燃烧后的热工艺气通过燃烧炉4直接进入废热锅炉401的入口管程，经降温后从顶部进入组合式反应器5。燃烧炉4与下游废热锅炉401直接连接，采用直接换热技术，热回收效率高，克服了设备易结垢和堵塞的缺陷。
在本实施例中，组合式反应器5的内部设有3个催化剂床层和2个段间换热器：分别记为第一催化剂床层501、第二催化剂床层503和第三催化剂床层505，段间换热器依次分布于相邻两个催化剂床层之间，分别记为第一段间换热器502、第二段间换热器504。第一催化剂床层501、第二催化剂床层503和第三催化剂床层505中装填有催化剂，床层的上部设人孔，下部设催化剂卸料口。在催化剂作用下，SO 2催化氧化转化为SO 3，燃烧反应段过量的助燃空气有助于提高SO 2的反应平衡转化率。该组合式反应器5结构紧凑，节约成本，优化空间布置，便于制造检修，而且有利于热能梯度回收利用，科学合理。
第一段间换热器502、第二段间换热器504底部与壳体部分采用槽钢梁进行固定；顶部与壳体部分采用锥壳进行连接，连接方式采用滑动连接，保证第一段间换热器502、第 二段间换热器504的自由伸缩；第一段间换热器502、第二段间换热器504与壳体相连的接管应有足够的长度，保持一定的挠性，防止对壳体产生过大的局部应力。
其中，工艺气体由组合式反应器5上部的入口进入，进入第一催化剂床层501。气体通过第一催化剂床层501后，完成部分转化，反应后的热气体通过床层下部的格栅板。格栅板上方依次铺设10*10mm-丝径Φ2mm的双层丝网，H＝75mm的Φ25毫米瓷球，3*3mm-丝径Φ1mm的双层丝网，防止催化剂破损落入下一层空间。工艺气穿过格栅板，通过锥壳进入第一段间换热器502；第一段间换热器502和第二段间换热器504采用蛇形管结构，中间采用三块支持板支撑，为保证自由伸缩，换热管与支持板不焊，保持滑动连接；换热管的外部用不锈钢板密封，防止工艺气通过换热管与支持板之间的空隙。依次类推，工艺气依次通过第二催化剂床层503，第二段间换热器504，第三催化剂床层505后，组合式反应器5的底部还设有一工艺气冷却器506，工艺气经工艺气冷却器506冷却后，然后从组合式反应器5的下出口流出。
硫酸蒸汽冷凝器1用于将SO 3工艺气冷凝形成硫酸；酸雾捕集器6与硫酸蒸汽冷凝器1连接，连接处位于硫酸蒸汽冷凝器1的进气口12与尾气排放口11之间，用于捕集脱出夹带的硫酸气溶胶。
如图2所示，本实施例中的硫酸蒸汽冷凝器1包括一竖直放置的长方形的壳体，该壳体的顶部具有一尾气排放口11，在壳体的底部具有一个输入SO 3工艺气的进气口12。在进气口12的下方还具有一个排液口13，用于排出冷凝后的浓硫酸。其中，该壳体的底部成半圆形结构，排液口13位于半圆形结构的最下方。当然，壳体底部可以为其他沿液体排出方向逐渐缩小的结构，例如倒三角形或者倒梯形。另外，壳体的顶部位于尾气排放口11的上游设有一作为过滤机构的纤维滤板3，用于过滤冷凝后产生的尾气中的液态小颗粒。
在壳体左、右两侧壁之间沿着长轴方向(即图2中竖直方向)垂直设有十二根玻璃管，所有玻璃管的两端均延伸至壳体的外部。在作为冷却介质的冷空气的流动方向的上游和下游之间相邻的两根玻璃管，即图2中上、下相邻的两根玻璃管依次首(端)尾(端)相连，从而形成一自上而下、单向导流的冷却介质流道。本实施例中，相邻的两根玻璃管通过一U型橡皮软管23连通。
该冷却介质流道包括一位于壳体上部的冷却介质进口和一位于壳体下部的冷却介质出口，冷空气从冷却介质进口进入，沿着冷却介质流道流动至冷却介质出口被排出。本实施例中，该冷却介质进口为玻璃管21的首端，冷却介质出口为玻璃管22的尾端。
本实施例所述的硫酸蒸汽冷凝器1中，由玻璃管形成的单向导流的冷却介质通道能 够耐受高温和强腐蚀，避免在高温和强腐蚀性环境中发生设备变形和腐蚀损毁现象，确保了冷凝器长时间使用，提高了硫酸蒸汽冷凝器1的使用安全性和流畅性。
本实施例中，酸雾捕集器6为一高速纤维除雾器。通过高效纤维除雾器物理捕集的方法，实现对酸雾的高效处理，除雾效率≥95％，压降小(≤1.0KPa)，不影响尾气排放。高速纤维除雾器采用高强度的纤维劈裂丝包裹PTFE的过滤网，编织为层状过滤器，当含有硫酸液滴(酸雾)的工艺气通过该过滤器时，通过强制拦截，实现对酸雾和其中夹带的硫酸气溶胶的高效捕集，而后尾气排至烟囱放空，过滤精度可达99.99％(≥0.5um)。
其中，通过内设的纤维滤板3与外置的高速纤维除雾器配合(替代了国外引进技术燃烧硅油制造凝结核的操作，该操作目的是增强硫酸蒸汽冷凝，降低尾气中硫酸气溶胶浓度)，除去气体中夹带的硫酸雾沫，可以达到较高的硫酸酸雾捕集率，放空尾气中基本不含酸雾，即使有微量酸雾(≤10ppm)，也能保证尾气中酸雾达标排放。
本实施例中，硫酸蒸汽冷凝器1的排液口13还与一硫酸混合罐7连接。
需要说明的是，当硫酸蒸汽冷凝器1的壳体为一圆柱体时，该圆柱体的轴线延伸方向即为壳体的长轴方向，而圆柱体绕该轴线回旋所形成的表面则为所述的侧壁。
另外，玻璃管的首端和尾端可均位于壳体内部，此时所述玻璃管的首、尾通过适配的玻璃管道连接。在此对所形成的冷却介质流道的形状不做限制，其可以为“弓”字型、“Z”字型或者其他形状。
其中，冷却介质一般为冷空气。当冷却介质为空气时，为配合冷空气下降的特性，上进下出的流向设计能进一步提高冷却介质的流动性，提高介质流速，继而提高冷凝效率。
本实施例中，酸雾捕集器6的液体出口也与硫酸混合罐7连接。
相应地，本实施例中的制酸工艺包括如下步骤：
(1)酸性气燃烧
燃烧炉4采用二级燃烧，即在炉膛内设置二次旋流器，相当于设置二次强制混合，可极大提高燃烧强度。
(2)工艺气催化氧化
燃烧后的工艺气再经过多级氧化，使SO 2工艺气催化氧化生成SO 3。
(3)硫酸蒸汽冷凝
由玻璃管形成的单向导流的冷却介质通道能够耐受高温和强腐蚀，避免在高温和强腐蚀性环境中发生设备变形和腐蚀损毁现象，确保了硫酸蒸汽冷凝器1长时间使用，提高硫酸蒸汽冷凝器1的使用安全性和流畅性。
(4)酸雾控制
酸雾控制采用多级精密强制拦截方式，直接控制出口酸雾≤10ppm。
(5)尾气零排放
本实施例中，酸雾捕集器6的尾气出口还与一尾气洗涤塔8连，尾气设置H 2O 2强效氧化单元，装置尾气中SO 2可降低至≤70mg/Nm 3，既痕量的SO 2通过H 2O 2稀溶液的洗涤，被H 2O 2直接氧化为SO 3，形成硫酸液滴，进而通过酸雾捕集器收集，并冷凝得到60％wt硫酸，并入硫酸产品中，如此实现尾气的超低排放，尾气SO 2可≤50mg/Nm 3，实现超低排放，可满足当前行业对环保的零排放的技术期望。
本实施例中，以流量2000Nm 3/h，H 2S：29.16mol％为酸性原料气数据，装置可处理H 2S当量20.4吨/天，可产硫酸(98wt％)当量63吨/天，过热蒸汽(420℃，4.0MPa)125.7吨。
步骤(1)中，酸性气的燃烧温度为903.7℃。助燃空气配比量为2.1倍。H 2S酸性气在燃烧炉内的反应停留时间1.5s。经废热锅炉401冷却后的工艺气温度为420℃。
步骤(2)中，热工艺气以420℃从顶部进入组合式反应器5的第一催化剂床层501，反应后温度提高至510℃，后在第一段间换热器502通过与装置所产蒸汽热量交换后降温至410℃，送入反应器第二催化剂床层503，反应后温度升至418℃，后在第二段间换热器504通过与装置所产蒸汽热量交换后降至385℃，最后进入反应器第三催化剂床层505，反应后最终气体温度约为381℃，经工艺气冷却器506降温至280℃，送入下游工艺中的硫酸蒸汽冷凝器1。
本实施例中，从步骤(2)排出的SO 3工艺气中水含量为9.96％。SO 3工艺气进入硫酸蒸汽冷凝器1的入口温度为290～295℃。本实施例中，硫酸蒸汽冷凝器1的出口热风温度保持在180℃左右。
SO 3工艺气进入硫酸蒸汽冷凝器1，进一步降低温度，促使硫酸蒸汽冷凝成硫酸。SO 3工艺气进入硫酸蒸汽冷凝器1，沿壳程由下向上流动。管程内送入的空气作为冷介质与热过程气交换热量而降低热过程气的温度至93℃，伴随热过程气温度降低，硫酸蒸汽逐步冷凝于玻璃换热管上，后结成液滴，靠重力滴落在硫酸蒸汽冷凝器1的底部。空气由一次风机提压后送至硫酸蒸汽冷凝器1，进入管箱的顶部，管箱分左右两端，分别通过内部隔板分割为多段，空气进入空气管箱后沿管箱内部的隔板横向进入玻璃换热管，冲刷玻璃管，与热过程气热量交换，出玻璃换热管后在空气管箱的另外一端汇集，然后继续进入管箱中的下一段，以此方式形成S型流，与过程气错流换热，最终离开硫酸蒸汽冷凝器1的空气温度约为180℃。硫酸蒸汽冷凝器1底部送出的硫酸温度约为252℃。
本实施例中，硫酸蒸汽冷凝器1的出口尾气温度控制在93℃以下；空气与尾气压差 控制在3Kpa。
本实施例中，由硫酸蒸汽冷凝产生的浓硫酸温度较高，还采取冷硫酸混合急冷以及换热降温至40℃，后送出界区。
本实施例中，送出硫酸蒸汽冷凝器1的热空气，部分经二次风机提高压力，送至装置前段的燃烧炉作为助燃空气，剩余的空气送烟囱放空，以提高放空尾气的温度及升力。
正常操作时，装置尾气排放情况如下：
SO 2：80mg/Nm 3(设计要求：<100)
SO 2排放速率：8.5kg/h
H 2S浓度：不可检出
H 2S排放速度：不可检出
COS+CS 2浓度：不可检出
COS+CS 2排放速度：不可检出
SO 3浓度：26mg/Nm 3(设计要求：<45)
SO 3排放速度：≤2.1kg/h
NO x浓度：80mg/Nm 3(设计要求：<240)
NO x排放速度：1.8kg/h
废水：无
废渣及废液：无
实施例2
本实施例的多级氧化制酸装置的工艺流程图、硫酸蒸汽冷凝器如图1～2所示，本实施例中，以流量34328Nm 3/h，H 2S浓度：1％mol为酸性原料气，可产硫酸(93wt％)当量142吨/天，过热蒸汽(420℃，4.0MPa)350.4吨/天。
步骤(1)中，酸性气的燃烧温度为896℃。助燃空气配比量为2.1倍。H 2S酸性气在燃烧炉内的反应停留时间1.5s。经废热锅炉401冷却后的工艺气温度为420℃。
步骤(2)中，热工艺气以420℃从顶部进入组合式反应器5的第一催化剂床层501，反应后温度提高至510℃，后在第一段间换热器502通过与装置所产蒸汽热量交换后降温至410℃，送入反应器第二催化剂床层503，反应后温度升至418℃，后在第二段间换热器504通过与装置所产蒸汽热量交换后降至385℃，最后进入反应器第三催化剂床层505，反应后最终气体温度约为381℃，经工艺气冷却器506降温至280℃，送入下游工艺中的硫酸蒸汽冷凝器1。
本实施例中，从步骤(2)排出的SO 3工艺气中水含量为9.96％。SO 3工艺气进入硫酸蒸汽冷凝器1的入口温度为290～295℃。本实施例中，硫酸蒸汽冷凝器1的出口热风温度保持在180℃左右。
SO 3工艺气进入硫酸蒸汽冷凝器1，进一步降低温度，促使硫酸蒸汽冷凝成硫酸。SO 3工艺气进入硫酸蒸汽冷凝器1，沿壳程由下向上流动。管程内送入的空气作为冷介质与热过程气交换热量而降低热过程气的温度至93℃，伴随热过程气温度降低，硫酸蒸汽逐步冷凝于玻璃换热管上，后结成液滴，靠重力滴落在硫酸蒸汽冷凝器1的底部。空气由一次风机提压后送至硫酸蒸汽冷凝器1，进入管箱的顶部，管箱分左右两端，分别通过内部隔板分割为多段，空气进入空气管箱后沿管箱内部的隔板横向进入玻璃换热管，冲刷玻璃管，与热过程气热量交换，出玻璃换热管后在空气管箱的另外一端汇集，然后继续进入管箱中的下一段，以此方式形成S型流，与过程气错流换热，最终离开硫酸蒸汽冷凝器1的空气温度约为180℃。硫酸蒸汽冷凝器1底部送出的硫酸温度约为252℃。
本实施例中，硫酸蒸汽冷凝器1的出口尾气温度控制在93℃以下；空气与尾气压差控制在3Kpa。
本实施例中，由硫酸蒸汽冷凝产生的浓硫酸温度较高，还采取冷硫酸混合急冷以及换热降温至40℃，后送出界区。
本实施例中，送出硫酸蒸汽冷凝器1的热空气，部分经二次风机提高压力，送至装置前段的燃烧炉作为助燃空气，剩余的空气送烟囱放空，以提高放空尾气的温度及升力。
正常操作时，装置尾气排放情况如下：
SO 2：50mg/Nm 3(设计要求：<100)
H 2S浓度：不可检出
H 2S排放速度：不可检出
COS+CS 2浓度：不可检出
COS+CS 2排放速度：不可检出
SO 3浓度：5mg/Nm 3(设计要求：<5)
NO x浓度：80mg/Nm 3(设计要求：<240)
废水：无
废渣及废液：无
虽然以上描述了本发明的具体实施方式，但是本领域的技术人员应当理解，这些仅是举例说明，在不背离本发明的原理和实质的前提下，可以对这些实施方式做出多种变 更或修改。因此，本发明的保护范围由所附权利要求书限定。

Claims (10)

  1. 一种硫化氢酸性气的多级氧化制酸装置，其特征在于，所述多级氧化制酸装置包括一H 2S燃烧装置、一与所述H 2S燃烧装置相连的组合式反应器、一硫酸蒸汽冷凝器和一酸雾捕集器；
    所述H 2S燃烧装置用于将硫化氢酸性气燃烧生成SO 2工艺气，所述组合式反应器用于将SO 2工艺气催化氧化生成SO 3工艺气，所述组合式反应器的内部设有若干个催化剂床层和分布于相邻两个所述催化剂床层之间的段间换热器；
    所述硫酸蒸汽冷凝器用于将SO 3工艺气冷凝形成硫酸，所述硫酸蒸汽冷凝器包括一壳体，所述壳体的顶部设有一尾气排放口，在所述壳体的底部具有一个输入SO 3工艺气的进气口，在所述进气口的下方还设有一排液口，在所述壳体内沿所述壳体的长轴方向设有用于流通冷却介质的若干玻璃管，所述玻璃管均跨设于所述壳体的两侧壁之间，所述玻璃管位于该冷却介质上游的一端为首端，位于该冷却介质下游的一端为尾端，在该冷却介质的上游和下游之间相邻的所述玻璃管首尾相连通从而形成至少一条单向导流的冷却介质流道；
    所述酸雾捕集器与所述硫酸蒸汽冷凝器连接，连接处设于所述进气口与所述尾气排放口之间的壳体上，用于捕集脱出夹带的硫酸气溶胶。
  2. 如权利要求1所述的多级氧化制酸装置，其特征在于，所述H 2S燃烧装置具有一烧嘴，所述烧嘴具有一中心通道和环设在所述中心通道外的一环形通道，所述中心通道用于通入H 2S酸性气与空气的混合气体，所述环形通道用于通入燃料气。
  3. 如权利要求1-2中至少一项所述的多级氧化制酸装置，其特征在于，所述H 2S燃烧装置为一燃烧炉，其炉膛内设置有二次旋流器；
    所述的燃烧炉还与一下游的废热锅炉直接连接，所述废热锅炉的气体出口还与所述组合式反应器的顶部连接。
  4. 如权利要求1-3中至少一项所述的多级氧化制酸装置，其特征在于，所述组合式反应器的内部设有3个催化剂床层和2个段间换热器，所述段间换热器依次分布于相邻两个所述催化剂床层之间，从上到下记为第一催化剂床层、第一段间换热器、第二催化剂床层、第二段间换热器和第三催化剂床层；所述组合式反应器的底部还设有一工艺气冷却器。
  5. 如权利要求1-4中至少一项所述的多级氧化制酸装置，其特征在于，所述硫酸蒸汽冷凝器的顶部还设有一纤维滤板；所述硫酸蒸汽冷凝器中，所述排液口还与一硫酸混 合罐连接；所述冷却介质流道设有一冷却介质进口和一冷却介质出口，所述冷却介质进口靠近所述硫酸蒸汽冷凝器的顶部，所述冷却介质出口靠近所述硫酸蒸汽冷凝器的底部；
    所述酸雾捕集器为一高速纤维除雾器；所述酸雾捕集器的液体出口也与所述硫酸混合罐连接；所述酸雾捕集器的尾气出口还与一尾气洗涤塔连接。
  6. 一种硫化氢酸性气的多级氧化制酸工艺，其特征在于，其采用如权利要求1-5至少一项所述的多级氧化制酸装置进行，其包括如下步骤：先将H 2S酸性气燃烧生成SO 2工艺气，再将SO 2工艺气催化氧化生成SO 3工艺气，然后冷凝成硫酸即可；H 2S酸性气中H 2S的浓度≥0.5％mol，该摩尔浓度为H 2S的摩尔量占H 2S酸性气的摩尔量的百分比。
  7. 如权利要求6所述的多级氧化制酸工艺，其特征在于，H 2S酸性气中H 2S的浓度为1％mol以上，较佳地为4％-15％mol。
  8. 如权利要求6-7中至少一项所述的多级氧化制酸工艺，其特征在于，H 2S酸性气中H 2S的浓度为20-30％mol，较佳地为29.16％mol。
  9. 如权利要求6-8中至少一项所述的多级氧化制酸工艺，其特征在于，H 2S酸性气的燃烧温度为800～1200℃；H 2S酸性气的燃烧过程中，空气配比量为化学当量的1.2～2.2倍，较佳地为2.1倍；
    H 2S酸性气在H 2S燃烧装置内的反应停留时间≥1.5s；
    当燃烧炉和组合式反应器之间还设有一废热锅炉时，经所述废热锅炉冷却后的SO 2工艺气的温度为410℃～430℃。
  10. 如权利要求6-9中至少一项所述的多级氧化制酸工艺，其特征在于，当所述组合式反应器的内部设有3个催化剂床层和2个段间换热器，所述段间换热器依次分布于相邻两个所述催化剂床层之间时，所述第一催化剂床层的SO 2工艺气进口温度控制在380℃以上；所述第二催化剂床层的工艺气进口温度控制在410℃以下；所述第三催化剂床层的工艺气进口温度控制在390℃以下；
    所述硫酸蒸汽冷凝器中，所述的冷却介质为冷空气；在冷凝过程中还通入H 2O 2溶液，用于将SO 3工艺气中夹带的痕量的SO 2氧化为SO 3，再经冷凝形成硫酸液滴；SO 3工艺气中水含量为9.96％；SO 3工艺气进入所述硫酸蒸汽冷凝器的入口温度为285～295℃，较佳地为290～295℃。
PCT/CN2019/128208 2019-01-04 2019-12-25 硫化氢酸性气的多级氧化制酸装置及制酸工艺 WO2020140799A1 (zh)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201910008441.9A CN109573959A (zh) 2019-01-04 2019-01-04 硫化氢酸性气的多级氧化制酸装置及制酸工艺
CN201910008441.9 2019-01-04
CN201920012748.1 2019-01-04
CN201920012748.1U CN209618891U (zh) 2019-01-04 2019-01-04 硫化氢酸性气的多级氧化制酸装置

Publications (1)

Publication Number Publication Date
WO2020140799A1 true WO2020140799A1 (zh) 2020-07-09

Family

ID=71407256

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/128208 WO2020140799A1 (zh) 2019-01-04 2019-12-25 硫化氢酸性气的多级氧化制酸装置及制酸工艺

Country Status (1)

Country Link
WO (1) WO2020140799A1 (zh)

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7252813B2 (en) * 2003-01-18 2007-08-07 Haldor Topsoe A/S Process for condensation of sulphuric acid vapours to produce sulphuric acid
US7361326B2 (en) * 2005-11-15 2008-04-22 Haldor Topsoe A/S Process for the production of sulfuric acid
CN102320579A (zh) * 2011-07-01 2012-01-18 上海科洋科技发展有限公司 硫化氢制备硫酸的工艺方法
CN102371108A (zh) * 2010-08-20 2012-03-14 中国石油化工集团公司 含硫化氢酸性气富氧空气焚烧生产硫酸的方法
CN202465273U (zh) * 2011-12-20 2012-10-03 上海科洋科技发展有限公司 湿法硫化氢制备硫酸的工艺***
CN103803506A (zh) * 2012-11-08 2014-05-21 中国石油化工股份有限公司 低排放硫化氢湿法制硫酸的工艺方法
CN106731582A (zh) * 2017-01-23 2017-05-31 科莱环境工程（北京）有限公司 一种综合处理含硫化氢酸性废气与固废杂盐的方法
CN206680184U (zh) * 2017-04-19 2017-11-28 宁波中科远东催化工程技术有限公司 一种使用酸性气体连续稳定地生产高浓度硫酸的***
CN207016486U (zh) * 2017-04-19 2018-02-16 宁波中科远东催化工程技术有限公司 一种使用酸性气体生产硫酸的***
CN109573959A (zh) * 2019-01-04 2019-04-05 科洋环境工程（上海）有限公司 硫化氢酸性气的多级氧化制酸装置及制酸工艺
CN209618891U (zh) * 2019-01-04 2019-11-12 科洋环境工程（上海）有限公司 硫化氢酸性气的多级氧化制酸装置

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7252813B2 (en) * 2003-01-18 2007-08-07 Haldor Topsoe A/S Process for condensation of sulphuric acid vapours to produce sulphuric acid
US7361326B2 (en) * 2005-11-15 2008-04-22 Haldor Topsoe A/S Process for the production of sulfuric acid
CN102371108A (zh) * 2010-08-20 2012-03-14 中国石油化工集团公司 含硫化氢酸性气富氧空气焚烧生产硫酸的方法
CN102320579A (zh) * 2011-07-01 2012-01-18 上海科洋科技发展有限公司 硫化氢制备硫酸的工艺方法
CN202465273U (zh) * 2011-12-20 2012-10-03 上海科洋科技发展有限公司 湿法硫化氢制备硫酸的工艺***
CN103803506A (zh) * 2012-11-08 2014-05-21 中国石油化工股份有限公司 低排放硫化氢湿法制硫酸的工艺方法
CN106731582A (zh) * 2017-01-23 2017-05-31 科莱环境工程（北京）有限公司 一种综合处理含硫化氢酸性废气与固废杂盐的方法
CN206680184U (zh) * 2017-04-19 2017-11-28 宁波中科远东催化工程技术有限公司 一种使用酸性气体连续稳定地生产高浓度硫酸的***
CN207016486U (zh) * 2017-04-19 2018-02-16 宁波中科远东催化工程技术有限公司 一种使用酸性气体生产硫酸的***
CN109573959A (zh) * 2019-01-04 2019-04-05 科洋环境工程（上海）有限公司 硫化氢酸性气的多级氧化制酸装置及制酸工艺
CN209618891U (zh) * 2019-01-04 2019-11-12 科洋环境工程（上海）有限公司 硫化氢酸性气的多级氧化制酸装置

Similar Documents

Publication Publication Date Title
CN101092577B (zh) 用煤气湿式氧化脱硫工艺生成的硫磺及废液制取硫酸的工艺及其设备
CN111285335B (zh) 一种硫泡沫及脱硫废液半干法制取硫酸的***及制酸方法
CN101054165A (zh) 一种硫磺回收与尾气处理装置及其硫磺回收与尾气处理的方法
CN102910593A (zh) 酸性气废气处理***及处理方法
CN104689679A (zh) 一种焦炉烟道废气脱硫脱硝工艺
CN103318847B (zh) 一种含硫化氢废气的高效硫回收方法
CN109482049B (zh) 一种焦炉烟气干法脱硫脱硝净化一体化工艺
CN103072957A (zh) 一种制取硫酸的工艺
CN109650346A (zh) 一种二次加压生产浓硫酸的湿法硫酸工艺***和方法
CN209618891U (zh) 硫化氢酸性气的多级氧化制酸装置
CN207016486U (zh) 一种使用酸性气体生产硫酸的***
CN101193690A (zh) 燃料气体的处理
CN201031142Y (zh) 一种再热炉制氢的硫磺回收与尾气处理装置
CN109573959A (zh) 硫化氢酸性气的多级氧化制酸装置及制酸工艺
CN100497165C (zh) 用煤气湿式氧化脱硫工艺生成的硫磺及废液制取硫酸的设备
RU2458857C2 (ru) Способ производства серной кислоты
CN101239705A (zh) 从含硫化氢气体中获得高纯硫的方法
CN202864918U (zh) 酸性气废气处理***
WO2020140799A1 (zh) 硫化氢酸性气的多级氧化制酸装置及制酸工艺
CN209507588U (zh) 处理焦炉煤气脱硫产低纯硫磺及副盐废液的装置
CN108178132B (zh) 一种二硫化碳生产中的硫回收方法及设备
RU2744704C2 (ru) Способ получения триоксида серы
RU2746896C2 (ru) Способ получения серной кислоты из серосодержащего исходного сырья с быстрым газовым охлаждением
CN108217606A (zh) 利用碳基材料还原脱硫解析气回收硫磺的错流移动床装置
CN208980334U (zh) 一种湿法制酸装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19906978

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19906978

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 05/10/2022)

122 Ep: pct application non-entry in european phase

Ref document number: 19906978

Country of ref document: EP

Kind code of ref document: A1