阅读说明：本技术 一种煤气精脱硫方法 (Gas fine desulfurization method ) 是由 许传东 于 2020-11-13 设计创作，主要内容包括：本发明公开了一种煤气精脱硫方法,包括碱液制备及输送、稀释水输送、羰基硫脱除药剂制备及输送、压力调节、脱硫反应和脱硫后处理等步骤。其中,羰基硫脱除药剂包括氧化剂和稳定剂,稳定剂包括络合铁和钛盐,氧化剂包括双氧水、次氯酸钠、亚氯酸钾和高锰酸钾。本发明公开的煤气精脱硫方法,所需设备投资成本低,结构简单易用,与传统催化水解工艺项目,投资和运行成本只有其30％。并且采用在TRT后喷入药剂和碱液的方式,对TRT的运行没有影响,克服了传统的催化水解工艺在TRT之前,水解后的硫化物在经过TRT时很容易腐蚀TRT的问题。(The invention discloses a coal gas fine desulfurization method, which comprises the steps of alkali liquor preparation and conveying, dilution water conveying, carbonyl sulfide removal agent preparation and conveying, pressure regulation, desulfurization reaction, desulfurization post-treatment and the like. Wherein, the carbonyl sulfide removal agent comprises an oxidant and a stabilizer, the stabilizer comprises complex iron and titanium salt, and the oxidant comprises hydrogen peroxide, sodium hypochlorite, potassium chlorite and potassium permanganate. The fine coal gas desulfurization method disclosed by the invention has the advantages of low investment cost of required equipment, simple structure and easiness in use, and the investment and operation cost is only 30% of that of the traditional catalytic hydrolysis process project. And the mode of spraying the medicament and the alkali liquor after the TRT is adopted, so that the operation of the TRT is not influenced, and the problem that the hydrolyzed sulfide is easy to corrode the TRT when passing through the TRT in the traditional catalytic hydrolysis process before the TRT is solved.)

1. The fine coal gas desulfurization method is characterized by comprising the following steps of,

step 1, preparing alkali liquor: adding water into industrial flake caustic soda with the purity of 99% and stirring the industrial flake caustic soda to prepare a sodium hydroxide solution with the concentration of 30%, and storing the sodium hydroxide solution in an alkaline liquor stainless steel storage tank;

step 2, conveying alkali liquor: adjusting and quantitatively conveying the alkali liquor obtained in the step 1 to a metering and mixing module according to tail gas hydrogen sulfide emission indexes, mixing the alkali liquor with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 3, conveying of dilution water: the dilution water is desalted water, and is conveyed to a metering and mixing module, mixed with alkali liquor or carbonyl sulfide removal agent and sprayed into a desulfurization reactor;

step 4, preparation of carbonyl sulfide removal agent: preparing a stabilizer and an oxidant, mixing the stabilizer and the oxidant according to a volume ratio of 1:3, adding water, stirring uniformly, and storing in a carbonyl sulfide removal agent storage tank, wherein the concentration of the carbonyl sulfide removal agent is 30%;

step 5, medicament delivery: regulating and quantitatively conveying the medicament to a metering and mixing module according to tail gas organic sulfur emission indexes, mixing the medicament with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 6, pressure regulation: arranging a pressure gauge on a coal gas inlet pipeline of the desulfurization reactor, detecting the pressure of the coal gas, adjusting a nitrogen pressure regulating valve according to the pressure of the coal gas, and controlling the amount of nitrogen entering the desulfurization reactor to maintain the pressure of the gas entering the desulfurization reactor stable;

step 7, desulfurization reaction: respectively spraying alkali liquor and carbonyl sulfide removal agent into a desulfurization reactor in a spraying manner, and carrying out desulfurization reaction by countercurrent contact with coal gas, wherein the reaction temperature is 10-120 ℃, the spraying flow rate in the reactor is designed to be 10-12m/s, the atomized particle size is controlled to be 70-100 microns, and the reaction time is controlled to be 0.5-0.8 second;

step 8, desulfurization post-treatment: comprises introducing the desulfurized coal gas into a demisting tower and recycling and discharging the wastewater generated in the demisting process.

2. The method for fine desulfurization of coal gas as claimed in claim 1, wherein in the step 4, the stabilizer comprises complex iron and titanium salt, and the oxidant comprises hydrogen peroxide, sodium hypochlorite, potassium chlorite and potassium permanganate.

3. The method for fine desulfurization of coal gas as claimed in claim 2, wherein in the stabilizer, the concentration of complex iron is 1.6-4.3%, and the concentration of titanium salt is 0.2-1.2%; in the oxidant, the concentration of hydrogen peroxide is 2-15%, the concentration of sodium hypochlorite is 4-20%, the concentration of potassium chlorite is 4-7%, and the concentration of potassium permanganate is 0.5-6%.

4. The method for fine desulfurization of gas as claimed in claim 1, wherein said spraying in step 7 is performed by using a two-fluid spray gun.

5. The fine desulfurization method for coal gas as claimed in claim 1, wherein the water content of the desulfurized coal gas in the step 8 is less than 5% after passing through the demister.

6. The fine desulfurization method for coal gas as claimed in claim 1, wherein a defogging washing device is provided to wash a defogger in the defogging tower, and the defogging washing device comprises a washing nozzle and a washing valve.

Technical Field

The application relates to a coal gas treatment process, in particular to a method for carrying out fine desulfurization on coal gas by using a medicament.

Background

In industrial gases closely related to coal, such as blast furnace gas, coke oven gas, water gas and the like, sulfur-containing gases generally exist, and mainly comprise hydrogen sulfide, sulfur dioxide, sulfur trioxide, carbonyl sulfide and the like. Sulfides can cause equipment corrosion and catalyst poisoning during production. In addition, sulfide gas discharged into the atmosphere without treatment is not only harmful to human bodies, but also promotes photochemical reaction, causing serious environmental problems. Therefore, sulfur-containing gas needs to be removed in the industries such as coal chemical industry.

The removal method of inorganic sulfur in sulfur-containing gas, such as hydrogen sulfide, stream sulfur oxide, etc., is relatively simple, but for organic sulfide gas such as carbonyl sulfide, etc., the removal method is difficult to remove by adopting a conventional method, and the current main removal technologies are an organic amine absorption method, a hydro-conversion method, a catalytic hydrolysis method, an oxidation conversion method, etc.

At present, the carbonyl sulfide removal of a steel mill mainly adopts a catalytic hydrolysis process, an alumina catalyst is mostly adopted, heavy metal components are contained in the components, the components are influenced by hydrogen chloride in blast furnace gas and react with the hydrogen chloride in the gas to produce chloride, so that the catalyst fails, and the catalyst is of a honeycomb structure, has large floor area and large gas resistance, and does not meet the requirements of energy conservation and environmental protection. Meanwhile, the process has the advantages of high investment cost, easy catalyst poisoning, high replacement cost, complex catalyst components after removal treatment, belonging to dangerous waste, high treatment difficulty and easy secondary pollution. The product after the catalytic hydrolysis process is desulfurized is sodium sulfide which is unstable and is easy to decompose to separate out hydrogen sulfide again, so that secondary pollution and personnel poisoning risks are caused. Catalytic hydrolysis process before TRT, hydrolyzed sulfides can easily corrode TRT when passing through it.

Disclosure of Invention

The invention provides a fine coal gas desulfurization method, which aims at solving the problems of high investment cost, high running cost, unstable removal efficiency, secondary pollution and the like of the existing domestic coal gas desulfurization technology, particularly carbonyl sulfide removal technology. By selecting a proper carbonyl sulfide removal agent and a process for oxidizing and absorbing carbonyl sulfide by using the agent, the desulfurization efficiency can reach 95 percent, the investment cost and the operation cost of the existing gas sulfur removal process can be greatly reduced, the investment cost and the operation cost are 30 percent of those of a catalytic hydrolysis process, and the problem of secondary pollution is avoided.

The purpose of the invention is realized by the following technical scheme.

A method for fine desulfurization of coal gas comprises the following steps.

Step 1, preparing alkali liquor: comprises adding water into industrial flake caustic soda (99% purity), stirring, preparing into 30% sodium hydroxide solution, and storing in alkaline stainless steel storage tank;

step 2, conveying alkali liquor: adjusting and quantitatively conveying the alkali liquor obtained in the step 1 to a metering and mixing module according to tail gas hydrogen sulfide emission indexes, mixing the alkali liquor with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 3, conveying of dilution water: the dilution water is desalted water, and is conveyed to a metering and mixing module, mixed with alkali liquor or carbonyl sulfide removal agent and sprayed into a desulfurization reactor;

step 4, preparation of carbonyl sulfide removal agent: preparing a stabilizer and an oxidant, mixing the stabilizer and the oxidant according to a volume ratio of 1:3, adding water, stirring uniformly, and storing in a carbonyl sulfide removal agent storage tank, wherein the concentration of the carbonyl sulfide removal agent is 30%;

step 5, medicament delivery: regulating and quantitatively conveying the medicament to a metering and mixing module according to tail gas organic sulfur emission indexes, mixing the medicament with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 6, pressure regulation: arranging a pressure gauge on a coal gas inlet pipeline of the desulfurization reactor, detecting the pressure of the coal gas, adjusting a nitrogen pressure regulating valve according to the pressure of the coal gas, and controlling the amount of nitrogen entering the desulfurization reactor to maintain the pressure of the gas entering the desulfurization reactor stable;

step 7, desulfurization reaction: respectively spraying alkali liquor and carbonyl sulfide removal agent into a desulfurization reactor in a spraying manner, and carrying out desulfurization reaction by countercurrent contact with coal gas, wherein the reaction temperature is 10-120 ℃, the spraying flow rate in the reactor is designed to be 10-12m/s, the atomized particle size is controlled to be 70-100 microns, and the reaction time is controlled to be 0.5-0.8 second;

step 8, desulfurization post-treatment: comprises introducing the desulfurized coal gas into a demisting tower and recycling and discharging the wastewater generated in the demisting process.

Preferably, the stabilizer comprises complex iron and titanium salt, and the oxidant comprises hydrogen peroxide, sodium hypochlorite, potassium chlorite and potassium permanganate.

Further preferably, in the stabilizer, the concentration of the complex iron is 1.6-4.3%, and the concentration of the titanium salt is 0.2-1.2%; in the oxidant, the concentration of hydrogen peroxide is 2-15%, the concentration of sodium hypochlorite is 4-20%, the concentration of potassium chlorite is 4-7%, and the concentration of potassium permanganate is 0.5-6%.

Preferably, the spraying in step 7 is performed using a two-fluid spray gun.

Preferably, in the step 8, after the desulfurized gas passes through the demisting tower, the water content is less than 5%.

Preferably, a demisting flushing device is arranged to flush demisters in the demisting tower, and the demisting flushing device comprises flushing nozzles and flushing valves.

The method for fine desulfurization of coal gas disclosed by the invention has the advantages of low investment cost of required equipment, simple structure and easiness in use, and small occupied area of the required equipment, and solves the problems of large occupied area and insufficient space of the traditional catalytic hydrolysis process. Compared with the traditional catalytic hydrolysis process project, the investment and operation cost is only 30 percent.

The method for fine desulfurization of coal gas disclosed by the invention has stable and efficient sulfur removal efficiency, and particularly can efficiently remove carbonyl sulfide. The selected carbonyl sulfide removing agent is added with a certain stabilizing agent on the basis of the traditional oxidant, carbonyl sulfide and hydrogen sulfide in the coal gas are selectively oxidized and do not react with carbon monoxide, carbon dioxide and hydrogen in the coal gas, the carbonyl sulfide and the hydrogen sulfide are oxidized into sulfur dioxide and sulfur trioxide, the sulfur dioxide and the sulfur trioxide are absorbed by alkaline solution sodium hydroxide and converted into sodium sulfate, and sodium sulfate water mist particles are removed by a demisting tower to obtain dry and clean coal gas.

The invention discloses a gas fine desulfurization method, which adopts a mode of spraying a medicament and alkali liquor after a TRT (blast furnace gas residual pressure turbine power generation device), has no influence on the operation of the TRT, and reduces the energy consumption and pressure energy loss of the TRT by the traditional catalytic hydrolysis process. The problem that the hydrolyzed sulfide is easy to corrode the TRT when passing through the TRT in the traditional catalytic hydrolysis process before the TRT is solved.

Detailed Description

The following are specific embodiments of the present invention for the purpose of illustration and description.

Example 1

A method for fine desulfurization of coal gas comprises the following steps.

Step 1, preparing alkali liquor: adding water into industrial flake caustic soda with the purity of 99% and stirring the industrial flake caustic soda to prepare a sodium hydroxide solution with the concentration of 30%, and storing the sodium hydroxide solution in an alkaline liquor stainless steel storage tank;

step 2, conveying alkali liquor: adjusting and quantitatively conveying the alkali liquor obtained in the step 1 to a metering and mixing module according to tail gas hydrogen sulfide emission indexes, mixing the alkali liquor with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 3, conveying of dilution water: the dilution water is desalted water, and is conveyed to a metering and mixing module, mixed with alkali liquor or carbonyl sulfide removal agent and sprayed into a desulfurization reactor;

step 4, preparation of carbonyl sulfide removal agent: preparing a stabilizer and an oxidant, mixing the stabilizer and the oxidant according to a volume ratio of 1:3, adding water, stirring uniformly, and storing in a carbonyl sulfide removal agent storage tank, wherein the concentration of the carbonyl sulfide removal agent is 30%; wherein, the stabilizer comprises 3 percent of complex iron and 0.5 percent of titanium salt, and the oxidant comprises 3 percent of hydrogen peroxide, 8 percent of sodium hypochlorite, 6 percent of potassium chlorite and 3 percent of potassium permanganate;

step 5, medicament delivery: regulating and quantitatively conveying the medicament to a metering and mixing module according to tail gas organic sulfur emission indexes, mixing the medicament with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 6, pressure regulation: arranging a pressure gauge on a coal gas inlet pipeline of the desulfurization reactor, detecting the pressure of the coal gas, adjusting a nitrogen pressure regulating valve according to the pressure of the coal gas, and controlling the amount of nitrogen entering the desulfurization reactor to maintain the pressure of the gas entering the desulfurization reactor stable;

step 7, desulfurization reaction: respectively spraying alkali liquor and carbonyl sulfide removal agent into a desulfurization reactor by using a two-fluid spray gun spraying mode, and carrying out desulfurization reaction by countercurrent contact with coal gas, wherein the reaction temperature is 80 ℃, the spraying flow rate in the reactor is designed to be 11m/s, the atomized particle size is controlled to be 80 micrometers, and the reaction time is controlled to be 0.6 second;

step 8, desulfurization post-treatment: introducing desulfurized coal gas into a demisting tower, controlling the water content of the coal gas passing through the demisting tower to be below 4%, and recovering and discharging waste water generated in the demisting process; and a washing nozzle and a washing valve are arranged to wash the demister in the demisting tower.

Example 2

A method for fine desulfurization of coal gas comprises the following steps.

Step 1, preparing alkali liquor: adding water into industrial flake caustic soda with the purity of 99% and stirring the industrial flake caustic soda to prepare a sodium hydroxide solution with the concentration of 30%, and storing the sodium hydroxide solution in an alkaline liquor stainless steel storage tank;

step 2, conveying alkali liquor: adjusting and quantitatively conveying the alkali liquor obtained in the step 1 to a metering and mixing module according to tail gas hydrogen sulfide emission indexes, mixing the alkali liquor with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 3, conveying of dilution water: the dilution water is desalted water, and is conveyed to a metering and mixing module, mixed with alkali liquor or carbonyl sulfide removal agent and sprayed into a desulfurization reactor;

step 4, preparation of carbonyl sulfide removal agent: preparing a stabilizer and an oxidant, mixing the stabilizer and the oxidant according to a volume ratio of 1:3, adding water, stirring uniformly, and storing in a carbonyl sulfide removal agent storage tank, wherein the concentration of the carbonyl sulfide removal agent is 30%; wherein, the stabilizer comprises 4.3 percent of complex iron and 0.2 percent of titanium salt, and the oxidant comprises 15 percent of hydrogen peroxide, 4 percent of sodium hypochlorite, 7 percent of potassium chlorite and 6 percent of potassium permanganate;

step 5, medicament delivery: regulating and quantitatively conveying the medicament to a metering and mixing module according to tail gas organic sulfur emission indexes, mixing the medicament with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 6, pressure regulation: arranging a pressure gauge on a coal gas inlet pipeline of the desulfurization reactor, detecting the pressure of the coal gas, adjusting a nitrogen pressure regulating valve according to the pressure of the coal gas, and controlling the amount of nitrogen entering the desulfurization reactor to maintain the pressure of the gas entering the desulfurization reactor stable;

step 7, desulfurization reaction: respectively spraying alkali liquor and carbonyl sulfide removal agent into a desulfurization reactor by using a two-fluid spray gun spraying mode, and carrying out desulfurization reaction by countercurrent contact with coal gas, wherein the reaction temperature is 120 ℃, the spraying flow rate in the reactor is designed to be 10m/s, the atomized particle size is controlled to be 100 micrometers, and the reaction time is controlled to be 0.8 second;

step 8, desulfurization post-treatment: introducing desulfurized coal gas into a demisting tower, controlling the water content of the coal gas passing through the demisting tower to be below 5%, and recovering and discharging waste water generated in the demisting process; and a washing nozzle and a washing valve are arranged to wash the demister in the demisting tower.

Example 3

A method for fine desulfurization of coal gas comprises the following steps.

Step 1, preparing alkali liquor: adding water into industrial flake caustic soda with the purity of 99% and stirring the industrial flake caustic soda to prepare a sodium hydroxide solution with the concentration of 30%, and storing the sodium hydroxide solution in an alkaline liquor stainless steel storage tank;

step 2, conveying alkali liquor: adjusting and quantitatively conveying the alkali liquor obtained in the step 1 to a metering and mixing module according to tail gas hydrogen sulfide emission indexes, mixing the alkali liquor with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 3, conveying of dilution water: the dilution water is desalted water, and is conveyed to a metering and mixing module, mixed with alkali liquor or carbonyl sulfide removal agent and sprayed into a desulfurization reactor;

step 4, preparation of carbonyl sulfide removal agent: preparing a stabilizer and an oxidant, mixing the stabilizer and the oxidant according to a volume ratio of 1:3, adding water, stirring uniformly, and storing in a carbonyl sulfide removal agent storage tank, wherein the concentration of the carbonyl sulfide removal agent is 30%; wherein, the stabilizer comprises 1.6 percent of complex iron and 1.2 percent of titanium salt, and the oxidant comprises 2 percent of hydrogen peroxide, 20 percent of sodium hypochlorite, 4 percent of potassium chlorite and 0.5 percent of potassium permanganate;

step 5, medicament delivery: regulating and quantitatively conveying the medicament to a metering and mixing module according to tail gas organic sulfur emission indexes, mixing the medicament with dilution water, conveying the mixture to a spray gun, and spraying the mixture into a desulfurization reactor;

step 6, pressure regulation: arranging a pressure gauge on a coal gas inlet pipeline of the desulfurization reactor, detecting the pressure of the coal gas, adjusting a nitrogen pressure regulating valve according to the pressure of the coal gas, and controlling the amount of nitrogen entering the desulfurization reactor to maintain the pressure of the gas entering the desulfurization reactor stable;

step 7, desulfurization reaction: respectively spraying alkali liquor and carbonyl sulfide removal agent into a desulfurization reactor by using a two-fluid spray gun spraying mode, and carrying out desulfurization reaction by countercurrent contact with coal gas, wherein the reaction temperature is 20 ℃, the spraying flow rate in the reactor is designed to be 12m/s, the atomized particle size is controlled to be 70 micrometers, and the reaction time is controlled to be 0.5 second;

step 8, desulfurization post-treatment: introducing desulfurized coal gas into a demisting tower, controlling the water content of the coal gas passing through the demisting tower to be below 4%, and recovering and discharging waste water generated in the demisting process; and a washing nozzle and a washing valve are arranged to wash the demister in the demisting tower.

Test example 1

And (3) investment comparison: a1 # furnace and a 2# furnace of a steel plant respectively adopt a catalytic hydrolysis process and the process disclosed by the invention, wherein the conditions of the 1# furnace and the 2# furnace are the same, the total investment of the catalytic hydrolysis process is 2500 ten thousand, and the total investment of the process disclosed by the invention is 750 ten thousand.

Compared with the investment of the traditional catalytic hydrolysis process, the investment cost of the coal gas fine desulfurization method disclosed by the invention is 30% of that of the catalytic hydrolysis process.

Test example 2

In Shanxi Jianbang iron and steel, the method for fine desulfurization of coal gas is adopted, and carbonyl sulfide medicament and sodium hydroxide solution are mixed and then sprayed into the coal gas for fine desulfurization in a two-stage spraying mode.

And (3) detecting the desulfurized coal gas, wherein the carbonyl sulfide and the hydrogen sulfide in the desulfurized coal gas are reduced from the original concentration of 70mg/Nm3 to 10mg/Nm3, so that the carbonyl sulfide and the hydrogen sulfide in the coal gas are effectively removed at the same time, one-time investment is achieved, and the effects of removing the hydrogen sulfide and the carbonyl sulfide are achieved at the same time.