Alkaline biological desulfurization system and method for hydrogen sulfide-containing gas
By combining chemical absorption and biooxidation technology in the spray tower and bioregeneration reactor, the problems of desulfurizer failure, high operating costs and difficult microorganisms in the prior art are solved, and efficient and low-cost gas desulfurization effect is achieved.
Patent Information
- Application Number
- CN202411949475.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-02-18
AI Technical Summary
In the desulfurization process, the prior art has problems such as desulfurization agent failure, improper waste treatment, high operating costs, possible secondary environmental pollution and difficulty in microorganisms in high temperature operating conditions.
A alkaline biodesulfurization system containing hydrogen sulfide gas, including components such as spray towers, bioregeneration reactors, chemical absorption is carried out through contact with the alkali liquid of the spray tower and then desulfurization is carried out through acclimation in the bioregeneration reactor. Bacteria undergo biological oxidation to achieve the removal of hydrogen sulfide and the regeneration of alkaline solution.
It realizes efficient removal of hydrogen sulfide in the gas, reduces operating costs, avoids air intervention and increases the risk of combustion and explosion, and reduces the impact on the subsequent gas purification process.
Smart Images
Figure CN119455643A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of biological desulfurization systems, in particular to an alkaline biological desulfurization system for hydrogen sulfide-containing gas and a method thereof. Background Art
[0002] Hydrogen sulfide is a common impurity component in gas, which is commonly found in coal chemical industry, natural gas, biogas, blast furnace gas, coalbed methane and other working gas. This component is highly toxic and can cause corrosion to process pipelines, gas treatment and utilization equipment (such as generators, boilers, etc.), posing a safety hazard. Therefore, desulfurization and purification are usually carried out before entering the treatment and utilization equipment.
[0003] The most commonly used desulfurization processes on the market are as follows:
[0004] 1. Dry desulfurization
[0005] In a dry desulfurization tower, H2S in the gas is removed by the reaction of desulfurizers (such as iron oxide, copper oxide, zinc oxide, etc.) with H2S. However, the desulfurizer will become ineffective after use, and the waste generated contains sulfur, which is flammable and can cause secondary pollution if not properly handled.
[0006] 2. Wet catalytic oxidation desulfurization
[0007] Wet catalytic desulfurization is to absorb the acidic gas hydrogen sulfide with an alkaline solution, and at the same time select an appropriate oxidation catalyst to oxidize the absorbed hydrogen sulfide in the solution into elemental sulfur, so that the circulating solution after absorbing hydrogen sulfide is regenerated and sulfur is obtained as a byproduct. The reduced catalyst can be oxidized by air to an oxidized state for recycling. The commonly used methods in the industry include cobalt phthalocyanine method, complex iron method, tannin extract method, PDS method, DDS method, etc.
[0008] In actual operation, the absorption of wet desulfurization alkali solution is affected by factors such as flow rate, flow rate, and temperature. The solubility of H2S is likely to be less than 100%, and NaHS is easily formed during desulfurization instead of Na2S. When NaHS is regenerated, it will react with O2 to form sulfate and thiosulfate. Harmful substances are enriched in the absorption liquid and the absorption capacity of the solution is reduced, so the desulfurization circulating liquid needs to be removed irregularly, the operating cost is high, and it may also cause secondary environmental pollution.
[0009] In addition, the sulfur produced by sulfur precipitation is chemical sulfur, which is insoluble in water and can easily clog the washing tower. In severe cases, the tower needs to be washed or the packing needs to be replaced every 1-3 months.
[0010] 3. Pure biological desulfurization
[0011] The pure biological desulfurization process is to introduce a certain amount of air into the biogas containing hydrogen sulfide. The mixed gas is converted into elemental sulfur by special bacteria (such as Thiothiobacillus or Thiobacillus) in the biological desulfurization tower, and then converted into dilute sulfuric acid (according to actual needs, the oxygen supply can also be adjusted to control the production ratio of sulfuric acid and elemental sulfur). The chemical reaction formula is as follows:
[0012] H2S+2O2→H2SO4
[0013] 2H2S+O2→2S+2H2O
[0014] S+H2O+1.5O2→H2SO4
[0015] The generated dilute sulfuric acid can be directly discharged into the "graywater reuse pool" or "regulating pool" for neutralization without further treatment.
[0016] Compared with the adsorption method and chemical desulfurization process, this method has a greater advantage in operating costs, but the introduction of air during the treatment process increases the risk of explosion. In addition, the increased oxygen component in the biogas has an adverse effect on the subsequent purification of natural gas. Moreover, in this process, the gas is in direct contact with microorganisms, and it is difficult for microorganisms to survive under high temperature conditions. Based on the above factors, the application of this method is also subject to certain limitations.
[0017] In summary, there is an urgent need for an alkaline biological desulfurization system and method for hydrogen sulfide gas to solve the above-mentioned problems. Summary of the invention
[0018] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an alkaline biological desulfurization system containing hydrogen sulfide gas, comprising a spray tower, an air distribution device is provided on the spray tower, and a packing bed is installed at the upper end of the air distribution device, a spray device is provided at the upper end of the packing bed, and a demisting device is provided at the upper end of the spray device, a desulfurization circulation pump is installed at the right side of the spray tower, and is connected to a biological regeneration reactor through the desulfurization circulation pump, an aeration device is provided on the inner side of the biological regeneration reactor, and an inclined tube sedimentation device is installed at the upper end of the aeration device, an aeration fan is connected to the right side of the aeration device, a water quality online detection pipeline is provided above the desulfurization circulation pump, and a heat exchanger is connected to the upper end of the water quality online detection pipeline, a sulfur separator is provided at the right side of the aeration fan, and a sludge pump is installed on the right side of the sulfur separator.
[0019] Preferably, in the biological regeneration reactor, oxygen is supplied by aeration, and by controlling the temperature of 20 to 40° C., the pH value of 7 to 10, and the redox potential parameters of -450 to -100, desulfurization bacteria suitable for the working conditions are domesticated and enriched. Through the specially domesticated desulfurization bacteria, the sulfur in the sulfur-rich liquid is converted into elemental sulfur through biological oxidation, and the alkali solution is regenerated.
[0020] Preferably, elemental sulfur enters the sulfur separator for clarification and separation, and is regularly discharged through a sludge pump. To ensure the dominant growth of desulfurization bacteria, nutrients and alkali solution with a certain ratio of nitrogen, phosphorus and potassium are regularly added, and waste liquid is regularly discharged or water is supplemented according to actual needs.
[0021] Preferably, the regenerated alkali solution is pumped to the spray device at the top of the spray tower through the desulfurization circulation pump for recycling.
[0022] An alkaline biological desulfurization method for hydrogen sulfide gas, which is applied to an alkaline biological desulfurization system for hydrogen sulfide gas, comprises the following steps:
[0023] Step 1: The gas first enters the spray tower, and the gas is evenly distributed in the tower through the gas distribution device. The uniform flow gas rises into the packing bed, contacts with the liquid film distributed on the surface of the packing sprayed downward from the regeneration alkali solution spray device above, and mass transfer and chemical reaction occur. The hydrogen sulfide in the rising gas is removed, and then it enters the demisting device at the top of the spray tower to remove the entrained mist;
[0024] Step 2: The purified gas is introduced into the subsequent treatment and utilization device, and the regenerated alkaline solution after absorbing hydrogen sulfide becomes a sulfur-rich liquid, flows downward, and enters the biological regeneration reactor through the connecting pipe at the bottom of the spray tower for regeneration.
[0025] Preferably, the empty tower flow rate of the spray tower is designed to be 0.1-1 m / s.
[0026] Preferably, the heat exchanger is an energy-saving device for realizing heat transfer between materials between two or more fluids at different temperatures, so that heat is transferred from a fluid with a higher temperature to a fluid with a lower temperature, so that the fluid temperature reaches the index specified by the process.
[0027] Preferably, in the spray tower, when the exhaust gas enters from the bottom of the tower body, it contacts with the spray medium sprayed from the spray tower. After contact, the exhaust gas or oil pollution is wrapped by water droplets, and the water droplets wrapped with pollutants collide again to increase the surface area and gravity.
[0028] Preferably, the sludge pump uses the volumetric conveying principle to achieve the purpose of conveying the sulfur sludge, and the sulfur sludge is pushed outward axially.
[0029] Preferably, the aeration fan has a flow rate of 20-500 standard meters per minute and a pressure of 3500-20000 mmH2O.
[0030] Compared with the prior art, the present invention has the following beneficial effects: the present invention has the advantages of both chemical absorption and biological regeneration technologies. The alkali solution spray tower is a chemical absorption unit, which has the characteristics of fast reaction and high desulfurization efficiency, and can achieve a gas outlet hydrogen sulfide concentration of less than 50ppm. The biological regeneration reactor makes full use of the low operating cost of the biological method to achieve the regeneration of the rich liquid after absorbing hydrogen sulfide for recycling.
[0031] In addition, by using the method of the present invention, air is not introduced during the gas desulfurization process, and the oxygen content in the gas will not be increased. Therefore, when gases such as biogas need to be decarbonized and purified after desulfurization, there will be no impurity components such as oxygen and nitrogen that affect the quality of the product gas. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Figure 1 It is a structural schematic diagram of the alkaline biological desulfurization system and method of hydrogen sulfide-containing gas of the present invention;
[0033] In the accompanying drawings: 1. Demisting device; 2. Spraying device; 3. Packing bed; 4. Air distribution device; 5. Spray tower; 6. Desulfurization circulation pump; 7. Water quality online detection pipeline; 8. Heat exchanger; 9. Biological regeneration reactor; 10. Aeration device; 11. Sedimentation device; 12. Aeration fan; 13. Sulfur separator; 14. Mud pump. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0035] See also Figure 1The present invention provides a technical solution: an alkaline biological desulfurization system for hydrogen sulfide gas, comprising a spray tower 5, an air distribution device 4 is provided on the spray tower 5, and a packing bed 3 is installed on the upper end of the air distribution device 4, a spray device 2 is provided on the upper end of the packing bed 3, and a demisting device 1 is provided on the upper end of the spray device 2, a desulfurization circulation pump 6 is installed on the right side of the spray tower 5, and is connected to a biological regeneration reactor 9 through the desulfurization circulation pump 6, an aeration device 10 is provided on the inner side of the biological regeneration reactor 9, and an inclined tube sedimentation device 11 is installed on the upper end of the aeration device 10, an aeration fan 12 is connected to the right side of the aeration device 10, a water quality online detection pipeline 7 is provided above the desulfurization circulation pump 6, and a heat exchanger 8 is connected to the upper end of the water quality online detection pipeline 7, a sulfur separator 13 is provided on the right side of the aeration fan 12, and a mud pump 14 is installed on the right side of the sulfur separator 13.
[0036] In the biological regeneration reactor 9, oxygen is supplied by aeration, and by controlling the temperature of 20 to 40° C., the pH value of 7 to 10, and the redox potential parameters of -450 to -100, desulfurization bacteria suitable for the working conditions are domesticated and enriched. Through the specially domesticated desulfurization bacteria, the sulfur in the sulfur-rich liquid is converted into elemental sulfur through biological oxidation, and the alkaline solution is regenerated.
[0037] Among them, elemental sulfur enters the sulfur separator 13 for clarification and separation, and is regularly discharged through the sludge pump 14. In order to ensure the dominant growth of desulfurization bacteria, nutrient salts and alkali solution with a certain ratio of nitrogen, phosphorus and potassium are regularly added, and waste liquid is regularly discharged or water is supplemented according to actual needs.
[0038] The regenerated alkali solution is sent to the spray device 2 at the top of the spray tower 5 through the desulfurization circulation pump 6 for recycling.
[0039] An alkaline biological desulfurization method for hydrogen sulfide gas, which is applied to an alkaline biological desulfurization system for hydrogen sulfide gas, comprises the following steps:
[0040] Step 1: The gas first enters the spray tower 5, and the gas is evenly distributed in the tower through the gas distribution device 5. The uniform flow gas rises and enters the packing bed 3, and contacts with the liquid film distributed on the surface of the packing sprayed downward from the regeneration alkali solution spray device above, and mass transfer and chemical reaction occur. The hydrogen sulfide in the rising gas is removed, and then the gas enters the demisting device 1 at the top of the spray tower 5 to remove the entrained mist;
[0041] Step 2: The purified gas is introduced into the subsequent processing and utilization device, and the regenerated alkaline solution after absorbing hydrogen sulfide becomes a sulfur-containing rich liquid, flows downward, and enters the biological regeneration reactor 9 through the connecting pipe at the bottom of the spray tower 5 for regeneration.
[0042] The empty tower flow rate of the spray tower 5 is designed to be 0.1-1 m / s.
[0043] The heat exchanger 8 is an energy-saving device for transferring heat between materials between two or more fluids at different temperatures, so that heat is transferred from a fluid with a higher temperature to a fluid with a lower temperature, so that the fluid temperature reaches the specified index of the process.
[0044] Among them, in the spray tower 5, when the exhaust gas enters from the bottom of the tower body, it contacts with the spray medium sprayed from the spray tower. After contact, the exhaust gas or oil is wrapped by water droplets, and the water droplets wrapped with pollutants collide again to increase the surface area and gravity.
[0045] Among them, the sludge pump 14 uses the volumetric conveying principle to complete the purpose of conveying sulfur sludge. The sulfur sludge is pushed outward axially.
[0046] The aeration fan 12 has a flow rate of 20-500 standard meters per minute and a pressure of 3500-20000 mmH2O.
[0047] It should be noted that the present invention is about an alkali biological desulfurization method for hydrogen sulfide gas, comprising the following steps: the gas first enters the spray tower, and the gas is evenly distributed in the tower through the gas distribution device, and the uniform flow gas rises into the packing bed, and contacts with the liquid film distributed on the surface of the packing sprayed downward from the regeneration alkali liquid spray device above, and mass transfer and chemical reaction occur, the hydrogen sulfide in the rising gas is removed, and then enters the demisting device at the top of the spray tower to remove the entrained mist, and the purified gas is introduced into the subsequent processing and utilization device. The regeneration alkali liquid after absorbing hydrogen sulfide becomes a sulfur-rich liquid, flows downward, and enters the biological regeneration reactor through the connecting pipe at the bottom of the spray tower for regeneration.
[0048] In the biological regeneration reactor, oxygen is supplied through aeration, and desulfurization bacteria suitable for the working conditions are domesticated and enriched by controlling appropriate parameters such as temperature (a range between 20 and 40°C), pH value (a range between 7 and 10), and redox potential (a range between -450 and -100). Through the specially domesticated desulfurization bacteria, the sulfur in the sulfur-rich liquid is converted into elemental sulfur through biological oxidation, and the alkali solution is regenerated. The elemental sulfur enters the sulfur precipitator for clarification and separation, and is regularly discharged through the sludge pump. In order to ensure the dominant growth of desulfurization bacteria, nutrients and alkali solution with a certain ratio of nitrogen, phosphorus and potassium are regularly added, and waste liquid or water is regularly discharged according to actual needs. The regenerated alkali solution is sent to the spray device at the top of the spray tower through the desulfurization circulation pump for recycling.
[0049] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.
[0050] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. An alkaline biological desulfurization system for hydrogen sulfide-containing gas, comprising a spray tower (5), characterized in that: The spray tower (5) is provided with an air distribution device (4), and a packing bed (3) is installed at the upper end of the air distribution device (4), a spray device (2) is provided at the upper end of the packing bed (3), and a demisting device (1) is provided at the upper end of the spray device (2). A desulfurization circulation pump (6) is installed at the right side of the spray tower (5), and is connected to a biological regeneration reactor (9) through the desulfurization circulation pump (6). An aeration device (10) is provided on the inner side of the biological regeneration reactor (9), and an inclined tube sedimentation device (11) is installed at the upper end of the aeration device (10). An aeration fan (12) is connected to the right side of the aeration device (10). An online water quality detection pipeline (7) is provided above the desulfurization circulation pump (6), and a heat exchanger (8) is connected to the upper end of the online water quality detection pipeline (7). A sulfur separator (13) is provided at the right side of the aeration fan (12), and a sludge pump (14) is installed on the right side of the sulfur separator (13).
2. The alkaline biological desulfurization system for hydrogen sulfide-containing gas according to claim 1, characterized in that: In the biological regeneration reactor (9), oxygen is supplied by aeration, and desulfurization bacteria suitable for the working conditions are domesticated and enriched by controlling the temperature between 20 and 40° C., the pH value between 7 and 10, and the redox potential parameters between -450 and -100. The sulfur in the sulfur-rich liquid is converted into elemental sulfur through biological oxidation by the specially domesticated desulfurization bacteria, and the alkali solution is regenerated.
3. The alkaline biological desulfurization system for hydrogen sulfide-containing gas according to claim 1, characterized in that: Elemental sulfur enters the sulfur separator (13) for clarification and separation, and is discharged regularly through the sludge pump (14). To ensure the dominant growth of desulfurization bacteria, nutrient salts and alkaline solution with a certain ratio of nitrogen, phosphorus and potassium are regularly added, and waste liquid is discharged regularly or water is added according to actual needs.
4. The alkaline biological desulfurization system for hydrogen sulfide-containing gas according to claim 1, characterized in that: The regenerated alkali solution is sent to the spray device (2) at the top of the spray tower (5) through the desulfurization circulation pump (6) for recycling.
5. An alkaline biological desulfurization method for hydrogen sulfide gas, which is applied to an alkaline biological desulfurization system for hydrogen sulfide gas, characterized in that: The alkaline biological desulfurization method of hydrogen sulfide-containing gas comprises the following steps: Step 1: The gas first enters the spray tower (5), and is evenly distributed in the tower through the gas distribution device (5). The uniform flow gas rises and enters the packing bed (3), contacts with the liquid film distributed on the packing surface sprayed downward from the regeneration alkali solution spray device above, and mass transfer and chemical reaction occur. The hydrogen sulfide in the rising gas is removed, and then the gas enters the demisting device (1) at the top of the spray tower (5) to remove the entrained mist; Step 2: The purified gas is introduced into the subsequent treatment and utilization device, and the regenerated alkaline solution after absorbing hydrogen sulfide becomes a sulfur-rich liquid, flows downward, and enters the biological regeneration reactor (9) through the connecting pipe at the bottom of the spray tower (5) for regeneration.
6. The alkaline biological desulfurization method of hydrogen sulfide-containing gas according to claim 5, characterized in that: The design value range of the empty tower flow rate of the spray tower (5) is 0.1-1 m / s.
7. The alkaline biological desulfurization method of hydrogen sulfide-containing gas according to claim 5, characterized in that: The heat exchanger (8) is an energy-saving device for realizing heat transfer between materials between two or more fluids at different temperatures, so that heat is transferred from a fluid with a higher temperature to a fluid with a lower temperature, so that the fluid temperature reaches the index specified by the process.
8. The alkaline biological desulfurization method of hydrogen sulfide-containing gas according to claim 5, characterized in that: In the spray tower (5), when the waste gas enters from the bottom of the tower body, it contacts the spray medium sprayed from the spray tower. After contact, the waste gas or oil pollution is wrapped by water droplets. The water droplets wrapped with pollutants collide again, increasing the surface area and gravity.
9. The alkaline biological desulfurization method of hydrogen sulfide-containing gas according to claim 5, characterized in that: The sludge pump (14) is a positive displacement mechanical device, through which the sulfur sludge at the bottom of the sulfur separator (13) is transported to the aerobic tank or other treatment units.
10. The alkaline biological desulfurization method of hydrogen sulfide-containing gas according to claim 5, characterized in that: The aeration fan (12) has a flow rate of 20-500 standard meters per minute and a pressure of 3500-20000 mmH2O.