CN-122006461-A - Device and method for biological desulfurization of sulfur-containing gas

CN122006461ACN 122006461 ACN122006461 ACN 122006461ACN-122006461-A

Abstract

The invention relates to the technical field of sulfur-containing gas treatment, in particular to a device and a method for biological desulfurization of sulfur-containing gas, wherein the device comprises an absorption unit, a desulfurization unit and a sulfur-containing rich liquid, wherein the absorption unit is used for absorbing sulfides in the sulfur-containing gas to obtain the sulfur-containing gas and the sulfur-containing rich liquid; the biological oxidation reaction unit is used for biologically oxidizing the sulfur-containing rich liquid, and the pressure control unit is arranged between the absorption unit and a communication pipeline of the biological oxidation reaction unit and is used for decompressing the sulfur-containing rich liquid and stabilizing the pressure. The biological desulfurization device can realize the stable control of the liquid seal slug liquid level at the bottom of the absorption tower, avoid the risk that high-pressure sulfur-containing gas or sulfur-containing gas with greatly fluctuating pressure in the absorption tower leaks to the atmosphere end through a connecting pipeline and a bioreactor, and effectively improve the desulfurization efficiency.

Inventors

WANG ZHIMING
WANG BIAO
QIAN ZHIHONG
MA MING
YANG FAN
GONG JIAYU

Assignees

中国石油化工股份有限公司
中国石油化工股份有限公司江苏油田分公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (12)

1. An apparatus for biological desulfurization of sulfur-containing gas, comprising: The absorption unit is used for absorbing sulfide in the sulfur-containing gas to obtain the sulfur-containing gas and the sulfur-containing rich liquid; A biological oxidation reaction unit for biological oxidation of the sulfur-containing rich liquid; The pressure control unit is arranged between the absorption unit and the communication pipeline of the biological oxidation reaction unit and is used for decompressing the sulfur-containing rich liquid and stabilizing the pressure.
2. The biological desulfurization apparatus according to claim 1, wherein, The absorption unit comprises an absorption tower (2) and a liquid sealing device, wherein the liquid sealing device is used for forming a liquid sealing slug at the bottom of the absorption tower (2), and/or The voltage control unit includes: a pressure reducing valve (17) for reducing the pressure of the sulfur-containing rich liquid; an electric regulating valve (18) arranged at the downstream of the pressure reducing valve (17) for regulating the flow of the sulfur-containing rich liquid, regulating the height of the liquid seal slug, and/or The biological oxidation reaction unit includes: A bioreactor (5) for the biological oxidation of the sulfur-containing rich liquor to obtain a slurry containing elemental sulfur, preferably the bioreactor (5) is a fluidized bed bioreactor, and/or The elemental sulfur separation system is used for separating slurry containing elemental sulfur to obtain elemental sulfur and regenerated alkali liquor.
3. The biological desulfurization apparatus according to claim 2, wherein, The absorption unit further comprises a scrubber (1) arranged upstream of the absorption tower (2) for removing non-gaseous substances from the sulfur-containing gas, and/or The bioreactor (5) further comprises an aeration unit for aerating the bioreactor (5), and/or A nutrient dosing device (12) for feeding a bioreactor (5) with a nutrient, and/or An alkali liquor dosing device (13) for feeding fresh alkali liquor to the bioreactor (5), and/or The elemental sulfur separation system includes: a sedimentation tank (8) for sedimentation of the slurry containing elemental sulfur to obtain elemental sulfur slurry and regenerated alkali liquor, and/or And a centrifuge (15) for separating the elemental sulfur slurry to obtain elemental sulfur.
4. The biological desulfurization apparatus according to claim 2 or 3, wherein the biological desulfurization apparatus further comprises a first automatic control unit for monitoring and controlling the liquid seal slugs; preferably, the first automatic control unit includes: a liquid level gauge arranged at the bottom of the absorption tower and used for monitoring the height of the liquid seal slug, and/or And a solenoid valve (19) arranged in series at the downstream of the electric regulating valve (18) for controlling the passage of the sulfur-containing rich liquid through opening and closing.
5. The biological desulfurization apparatus according to any one of claims 2 to 4, further comprising a second automatic control unit for monitoring and controlling the biological oxidation reaction unit; preferably, the second automatic control unit includes: Thermometer, flowmeter, level gauge, pH gauge, ORP gauge, sludge concentration gauge, dissolved oxygen gauge and conductivity gauge disposed within the bioreactor (5), and/or And the temperature regulating unit is used for regulating and controlling the reaction temperature in the bioreactor (5).
6. The biological desulfurization apparatus according to any one of claims 2 to 5, wherein the biological desulfurization apparatus further comprises: A first transfer pump (7) for circulating the slurry containing elemental sulfur in the bioreactor (5) to the absorption column (2), and/or And a gas-liquid separator (3) for separating the gas from the liquid of the desulfurization gas.
7. A method for biological desulfurization of sulfur-containing gas, characterized in that it employs the biological desulfurization apparatus according to any one of claims 1 to 6, comprising: the sulfur-containing gas is contacted with alkali liquor in the absorption unit to obtain sulfur-containing gas and sulfur-containing rich liquor, and the sulfur-containing rich liquor is decompressed to 0.1-0.3MPa and then enters the biological oxidation reaction unit for biological oxidation.
8. The biological desulfurization method according to claim 7, wherein the method comprises: The sulfur-containing gas is contacted with a washing medium in a gas washing tower (1), non-gaseous substances in the sulfur-containing gas are removed, and the gas enters an absorption tower (2) to be contacted with alkali liquor to obtain sulfur-containing gas and sulfur-containing rich liquor; the sulfur-containing rich solution is decompressed to 0.1-0.3MPa and then enters a bioreactor (5) for biological oxidation; Preferably, the method further comprises: dehydrating the desulfurized gas by a gas-liquid separator (3) to obtain dehydrated gas, and/or Aeration of the bioreactor (5) by means of an aeration unit, and/or And separating the slurry containing the elemental sulfur obtained by biological oxidation to obtain the elemental sulfur and regenerated alkali liquor.
9. The biological desulfurization method according to claim 7 or 8, wherein, The biological oxidation adopts a composite sulfur removal microbial inoculum, preferably one or more of alkali-resistant sulfur oxidizing bacteria; Preferably, the alkaline-tolerant sulfur oxidizing bacteria are selected from one or more of pseudomonas, pallidum, geobacillus, thiobacillus, vibrio thioalcaligenes and thiobacillus denitrificans; more preferably one or more of Pseudomonas, xanthium, geobacillus, and/or The biological desulfurization method also comprises the step of circulating the slurry containing the elemental sulfur to an absorption tower (2) through a circulating pump.
10. The biological desulfurization method according to any one of claims 7-9, wherein, The sulfur-containing gas comprises one or more of sulfur-containing natural gas, biogas, blast furnace gas and petrochemical plant exhaust gas, preferably has a latent sulfur content of 0.001-5t/d, and/or The pressure of the sulfur-containing gas is 0.1-5MPa, and/or The amount of the sulfur-containing gas is not less than 1000m 3 /d, preferably 1000-8000m 3 /d, and/or The biological oxidation temperature is 10-45deg.C, preferably 30-37deg.C, and/or The pH of the lye is 7-10, preferably 7.5-8.5.
11. The biological desulfurization method according to any one of claims 7-10, wherein, In the absorption tower (2), the height of the liquid seal slug is 10-100cm; preferably, the flow of the sulfur-containing rich liquid is regulated and controlled through an electric regulating valve (18), and the height of the liquid seal slug is regulated and controlled; preferably, the biological desulfurization method further comprises: The opening and closing of the sulfur-containing rich liquid are controlled through an electromagnetic valve (19), when the height of the liquid seal slug is lower than 10cm, the electromagnetic valve (19) is closed, when the height of the liquid seal slug is higher than 10cm, the liquid seal slug is kept normally open, and when the system is suddenly powered off, the electromagnetic valve (19) is closed.
12. The biological desulfurization method according to any one of claims 7-11, wherein, The biological desulfurization method further comprises the steps of collecting operation data in real time through a second automatic control unit and automatically controlling all parameters.

Description

Device and method for biological desulfurization of sulfur-containing gas Technical Field The invention relates to the technical field of sulfur-containing gas treatment, in particular to a device and a method for biological desulfurization of sulfur-containing gas. Background With the global increasing demand for energy, natural gas is also continuously increasing in demand as a clean, efficient energy source. However, natural gas contains harmful substances such as hydrogen sulfide, which can cause environmental pollution, equipment corrosion and serious influence on human health. Thus, desulfurization is an essential element in the exploitation, transportation and use of natural gas. Natural gas desulfurization processes include physical, chemical and biological processes. The physical method mainly separates the hydrogen sulfide from the natural gas by physical adsorption, physical absorption and other modes. The method has the advantages of simplicity and rapidity, but the adsorbent needs to be regenerated periodically, and the operation cost is high. The chemical method mainly converts hydrogen sulfide into other harmless substances such as sulfur and the like through chemical reaction. The method has the advantages of high desulfurization efficiency, high cost and high consumption of a large amount of chemical reagents. The natural gas desulfurization technology by various physical methods and chemical methods has complex process, difficult control of production process, higher operation cost and possible secondary pollution. The existing natural gas desulfurization process mainly comprises an alcohol amine method, a dry desulfurization method, a low-temperature methanol method, a complex iron method and the like. Alcohol amine processes are currently the most used process for the desulfurization of natural gas. The method mainly removes hydrogen sulfide through the chemical absorption of alcohol amine solvents, and common alcohol amine solvents include monoethanolamine, diethanolamine, diisopropanolamine, methyldiethanolamine and the like. The method has mature process, but still has the problems of heavy equipment, high investment cost, regeneration, environmental pollution and the like. The biggest problem is the regeneration of the absorption liquid. The regeneration method mainly comprises high-temperature reduced pressure distillation, and has the advantages of high recovery energy consumption, large investment and low regeneration recovery liquid rate. Dry desulfurization is the removal of hydrogen sulfide by passing a gas through a bed of solid adsorbent. Common solid adsorbents are sponge iron, activated carbon, alumina, zeolite foam, molecular sieves, and the like. Are often used for treating gases containing trace amounts of hydrogen sulphide. The method is intermittent operation, and has the problems of heavy equipment, high investment, low treatment capacity, difficult regeneration of the adsorbent, high development difficulty and the like. The low-temperature methanol washing method utilizes the good characteristic of extremely high solubility of methanol to acid gas at low temperature to remove the acid gas in the raw material gas. The low-temperature methanol has better heat transfer and mass transfer performance, strong selectivity, high purification degree, small corrosiveness, low cost, investment cost saving, no oxidation and degradation of the solvent, good chemical and thermal stability, no foaming in the absorption process and stable production. However, methanol is toxic, and a refrigerating system needs to be added, so that the operation and maintenance are difficult. And the technology belongs to foreign technology, needs to purchase a patent software package, and has larger one-time investment. The complex iron method converts H 2 S into sulfur by using high-valence iron ions, and the high-valence iron ions are regenerated through oxidation, so that hydrogen sulfide is circularly absorbed. Its advantages are high desulfurizing rate, short process, simple equipment and mature technology. The method has the defects of high investment, large occupied area, high running cost and dangerous waste of produced sulfur. The biological method is an emerging desulfurization method, and mainly utilizes the metabolism of microorganisms to convert hydrogen sulfide into elemental sulfur or other harmless substances. The method has the advantages of low cost and strong adaptability. The natural gas biological desulfurization technology is still in laboratory exploration stage in China at present, and a plurality of difficulties need to be overcome when the natural gas biological desulfurization technology is applied to industrial sites. Therefore, how to develop a natural gas desulfurization process technology with low cost, high efficiency and strong adaptability is a problem to be solved in the field at present. Disclosure of Invention In order to overcome the defects that in the prior ar