WO2022111319A1

WO2022111319A1 - Sulfur dioxide adsorbent, preparation method therefor and use thereof

Info

Publication number: WO2022111319A1
Application number: PCT/CN2021/130535
Authority: WO
Inventors: 朱荣海; 胡勇; 张素娟; 何金龙; 常宏岗; 李金金; 赵国星; 温崇荣; 余军; 马枭; 刘宗社; 张晓雪
Original assignee: 中国石油天然气股份有限公司
Priority date: 2020-11-25
Filing date: 2021-11-15
Publication date: 2022-06-02
Also published as: CN114534681B; CN114534681A

Abstract

The present invention provides a sulfur dioxide adsorbent, a preparation method therefor and a use thereof. The preparation method comprises the following steps: (1) dissolving an iron salt and an alkali metal salt in water to obtain a mixed salt solution; (2) mixing an alkaline earth metal-containing material, a binder and auxiliary agents with the mixed salt solution uniformly to obtain an intermediate; and (3) kneading and extruding the intermediate, followed by drying and roasting treatment, to obtain the sulfur dioxide adsorbent. The adsorbent is prepared without using high-priced transition metal elements, rare earth metal elements and hydrotalcite, greatly reducing production cost; and the sulfur capacity is as high as 0.79 g/g, facilitating large-scale use.

Description

A kind of sulfur dioxide adsorbent and its preparation method and application

technical field

The invention relates to the technical field of adsorbents, in particular to a sulfur dioxide adsorbent and a preparation method and application thereof.

Background technique

Sulfur dioxide is one of the main industrial air pollutants. Strictly controlling the concentration of sulfur dioxide emissions to reduce air pollution has always been an important issue of environmental protection in my country. Therefore, it is necessary to treat sulfur dioxide.

Sulfur dioxide adsorbents are classified according to the temperature of use, generally including low-temperature adsorbents and high-temperature adsorption. The low-temperature adsorption of sulfur dioxide is generally dominated by activated carbon and modified activated carbon. The operating temperature is generally lower than 200 °C, and the sulfur capacity is low. In order to obtain a higher sulfur capacity, a high temperature adsorbent is generally required. Patent 201310219881.1 discloses a sulfur dioxide adsorbent for adsorbing sulfur dioxide. The sulfur dioxide adsorbent is prepared by the following method: mixing hydrotalcite-like oxides with rare earth salts, adding a binder, and forming and calcining to obtain a sulfur dioxide adsorbent . The adsorption and regeneration temperatures of the sulfur dioxide adsorbent were both 500° C., and the average sulfur capacity of the adsorbent reached 0.1 g/g. However, studies have found that the regeneration temperature condition of 500 °C has the disadvantages of high energy consumption and poor economy in actual implementation. Patent 201910110758.3 discloses a sulfur dioxide adsorbent, which is prepared by extrusion molding of oxidative metal salts, transition metal salts, alkali metal salts, magnesium-aluminum compounds and extrusion aids. The adsorption and regeneration temperature is reduced from 500 ° C to 350 ° C and Below, the power consumption is greatly reduced. This technology still requires the participation of reducing gas, and the process flow is still long.

In the prior art, low-temperature activated carbon adsorbents have disadvantages such as low sulfur capacity and large adsorbent filling volume. The use of transition metal elements, rare earth metal elements, etc. for high-temperature adsorbents causes high costs, and the regeneration process will cause the device process flow to become longer. Investment and operating costs increase.

SUMMARY OF THE INVENTION

In order to solve the above problems, the purpose of the present invention is to provide a sulfur dioxide adsorbent, which has the advantages of high operating temperature, high sulfur dioxide adsorption capacity, and no toxic and harmful heavy metals.

Another object of the present invention is to provide a preparation method of the above-mentioned sulfur dioxide adsorbent.

Another object of the present invention is to provide the application of the above-mentioned sulfur dioxide adsorbent.

In order to achieve the above object, on the one hand, the present invention provides a preparation method of a sulfur dioxide adsorbent, wherein the preparation method comprises the following steps: (1) dissolving iron salt and alkali metal salt in water to obtain a mixed salt solution, The mass ratio of the iron salt to the alkali metal salt is (3-100): 1; (2) mixing the alkaline earth metal-containing substance, the binder and the auxiliary agent with the mixed salt solution to obtain an intermediate material; (3) Kneading and extruding the intermediate material, and sequentially drying and calcining to obtain the sulfur dioxide adsorbent.

According to some specific embodiments of the present invention, in step (1), in step (1), the mass ratio of the iron salt to the alkali metal salt is (3-30): 1, more preferably (3-10 ):1, more preferably (3-5):1, further preferably 4:1.

According to some specific embodiments of the present invention, in step (1), the iron salt is selected from one or both of ferric nitrate, ferrous nitrate, ferric sulfate, ferrous sulfate, ferric chloride and ferrous chloride combination of the above.

According to some specific embodiments of the present invention, in step (1), the iron salt is selected from one or more combinations of ferric nitrate, ferrous nitrate, ferric sulfate and ferric chloride, preferably from ferrous nitrate and one or a combination of ferric sulfate, more preferably ferrous nitrate.

According to some specific embodiments of the present invention, in step (1), the alkali metal salt is selected from one or a combination of two or more of sodium chloride, sodium sulfate, potassium chloride and potassium sulfate.

According to some specific embodiments of the present invention, in step (1), the alkali metal salt is selected from one or a combination of potassium chloride and sodium sulfate, preferably potassium chloride.

According to some specific embodiments of the present invention, in step (2), the mass ratio of the alkaline earth metal-containing substance to the auxiliary agent is (25-50): 1, preferably (30-45): 1, more preferably 44:1.

According to some specific embodiments of the present invention, in step (2), the alkaline earth metal-containing substance is selected from one or a combination of calcium-containing substances and magnesium-containing substances.

According to some specific embodiments of the present invention, in step (2), the calcium-containing substance is selected from one or a combination of two or more of calcium oxide, calcium hydroxide and calcium carbonate.

According to some specific embodiments of the present invention, in step (2), the calcium-containing substance is selected from one or a combination of calcium oxide and calcium carbonate.

According to some specific embodiments of the present invention, in step (2), the magnesium-containing substance is selected from one or a combination of two or more selected from magnesium oxide, magnesium hydroxide, magnesium carbonate and basic magnesium carbonate.

According to some specific embodiments of the present invention, in step (2), the magnesium-containing substance is selected from one or a combination of magnesium hydroxide and basic magnesium carbonate, preferably from magnesium hydroxide.

According to some specific embodiments of the present invention, in step (2), the mass ratio of the binder to the auxiliary agent is (3-35): 1, preferably (10-35): 1, more preferably 30:1.

According to some specific embodiments of the present invention, in step (2), the binder is selected from one of boehmite, pseudo-boehmite, aluminum hydroxide, sodium silicate, water glass and cement or combination of two or more.

According to some specific embodiments of the present invention, in step (2), the binder is selected from one or more combinations of pseudoboehmite, cement, water glass and aluminum hydroxide, and is further preferably selected from One or a combination of one or both of cement and water glass, more preferably from cement.

According to some specific embodiments of the present invention, in step (2), the auxiliary agent is selected from one or a combination of two or more selected from succulent powder, carboxymethyl cellulose, polyvinyl alcohol and activated carbon powder, preferably activated carbon One or a combination of the powder and carboxymethyl cellulose, more preferably from activated carbon powder.

According to some specific embodiments of the present invention, in step (2), the extrusion molding is completed by an extruder.

According to some specific embodiments of the present invention, in step (2), an orifice plate with a diameter of 1 mm-6 mm is installed in the extruder.

According to some specific embodiments of the present invention, in step (2), the drying includes shade-drying and drying in sequence, wherein the shade-drying is drying at room temperature for 6h-48h, preferably 12-48h, It is further preferably 48h; the drying temperature is 60°C-150°C, preferably 60°C-110°C, more preferably 60°C, and the drying time is 2h-48h, preferably 48h.

According to some specific embodiments of the present invention, in step (2), the temperature of the calcination treatment is 400°C-600°C, preferably 400°C-500°C, more preferably 400°C.

According to some specific embodiments of the present invention, in step (2), the calcination treatment time is 1h-10h, more preferably 4h-10h, further preferably 10h.

The present invention also provides the sulfur dioxide adsorbent prepared by the above preparation method.

The present invention also provides the preparation method of the above-mentioned sulfur dioxide adsorbent or the application of the above-mentioned sulfur dioxide adsorbent in the high-temperature adsorption of sulfur dioxide.

Beneficial effects of the present invention:

(1) The preparation method of the sulfur dioxide adsorbent provided by the present invention is to prepare a low-cost sulfur dioxide adsorbent by extruding iron salts, alkali metal salts, alkaline earth metal-containing substances, binders and auxiliary agents, and the sulfur dioxide adsorbs The preparation process of the agent does not use high-priced transition metal elements, rare earth metal elements and hydrotalcite, which greatly reduces the production cost and facilitates large-scale popularization and application.

(2) The adsorbent provided by the present invention is used under high temperature flue gas conditions without cooling operation, and the sulfur capacity is much higher than that of the existing adsorbent, up to 0.79 g/g.

(3) Since the adsorbent does not need to be regenerated, the sulfur dioxide adsorption process becomes simpler, and the cost of device construction is greatly reduced.

(4) The sulfur dioxide adsorbent of the present invention does not use elements harmful to the environment such as toxic and harmful heavy metals, which facilitates the treatment of the adsorbent after use.

Description of drawings

Fig. 1 is a laboratory sulfur capacity evaluation device in an application example of the present invention.

Description of reference numerals: 1-valve, 2-flow meter, 3-water storage tank, 4-mixer, 5-pressure gauge, 6-preheater, 7-heating furnace, 8-sampling point, 9-temperature measurement point, 10-reactor, 11-adsorbent, 12-sampling point, 13-alkali washing bottle, 14-venting device, 15-water pump.

Detailed ways

In order to make the technical solutions and advantages of the present invention clearer, the embodiments of the present invention are further described in detail below. Where not specifically described, it was carried out in accordance with routine laboratory operations.

Example 1

The present embodiment provides a preparation method of a sulfur dioxide adsorbent, and the specific steps are as follows:

Dissolve 1 g of ferric nitrate and 0.01 g of sodium chloride in 80 mL of water to obtain a mixed salt solution; mix 86 g of calcium oxide, 10 g of pseudoboehmite and 3 g of succulent powder with the mixed salt solution to obtain an intermediate material.

Place the intermediate material in a kneading device to fully knead the intermediate material, and then use a circular orifice plate with a diameter of 1 mm in a single-screw extruder for extrusion molding, and the extruded sample is dried in the air for 24 hours. , drying in an oven at 150° C. for 8 hours, and then roasting in a muffle furnace at 600° C. for 1 hour, to obtain the desired low-cost sulfur dioxide adsorbent in this example.

Example 2

Dissolve 20 g of ferrous nitrate and 5 g of potassium chloride in 80 mL of water to obtain a mixed salt solution; mix 44 g of magnesium hydroxide, 30 g of cement and 1 g of activated carbon powder with the mixed salt solution to obtain an intermediate material.

The intermediate material is placed in a kneading device to fully knead the intermediate material, and then a circular orifice plate with a 6mm aperture is used for extrusion molding in a single-screw extruder, and the extruded sample is dried in the air for 48 hours. , drying in an oven at 60°C for 48h, and then roasting in a muffle furnace at 400°C for 10h, the desired low-cost sulfur dioxide adsorbent in this example can be obtained.

Example 3

Dissolve 10 g of ferric sulfate and 2 g of sodium sulfate in 80 mL of water to obtain a mixed salt solution; mix 66 g of calcium carbonate, 20 g of water glass and 2 g of carboxymethyl cellulose with the mixed salt solution to obtain an intermediate material.

The intermediate material is placed in a kneading device to fully knead the intermediate material, and then extruded into a single-screw extruder using a circular orifice plate with a diameter of 3 mm, and the extruded sample is dried in the air for 12 hours. , drying in an oven at 105°C for 2 hours, and then roasting in a muffle furnace at 500°C for 4 hours, the desired low-cost sulfur dioxide adsorbent in this example can be obtained.

Example 4

Dissolve 15g of ferric chloride and 2g of potassium sulfate in 80mL of water to obtain a mixed salt solution; mix 71g of basic magnesium carbonate, 10g of aluminum hydroxide and 2g of polyvinyl alcohol with the mixed salt solution to obtain an intermediate material.

The intermediate material was placed in a kneading device to fully knead the intermediate material, and then extruded into a single-screw extruder using a circular orifice plate with a diameter of 4 mm, and the extruded sample was dried in the air for 6 hours. After drying in an oven at 105° C. for 4 hours, and then roasting in a muffle furnace at 500° C. for 6 hours, the desired low-cost sulfur dioxide adsorbent in this example can be obtained.

Application Example

In this example, the adsorption sulfur capacity (abbreviation: sulfur capacity) of the sulfur dioxide adsorbent provided by Example 1-Example 4 is tested, and the test method is as follows:

The adsorption regeneration evaluation experiment was carried out using the sulfur dioxide adsorbent provided in Example 1-Example 4.

The adsorption regeneration evaluation experiment is to simulate the sulfur dioxide adsorption reactor on the evaluation device, including temperature, gas composition, space velocity and other conditions, and calculate the sulfur capacity of the adsorbent by measuring the sulfur dioxide content in the tail gas.

1. Sulfur capacity evaluation conditions:

(1) Adsorbent bed temperature: (500±2)℃.

(2) Reaction pressure (gauge pressure): <50kPa.

(3) Volume air velocity: 500h ^-1 .

(4) Capacity of adsorbent: 40mL.

(5) The particle size of the adsorbent: the aperture of the standard sample sieve is 1.5mm to 2.5mm.

(6) See Table 1 for the composition and concentration of the feed gas.

(7) Reactor specifications:

Table 1 Composition and concentration of feed gas

2. Process of sulfur capacity evaluation device

The laboratory sulfur capacity evaluation device is shown in Figure 1.

The detection process of the sulfur capacity evaluation device is as follows:

Nitrogen, carbon dioxide and sulfur dioxide are respectively input to mixer 4 through valve 1 and flow meter 2; at the same time, the water in water storage tank 3 is circulated to mixer 4 through water pump 15; then the components in mixer 4 are input to preheater 6, the preheater 6 is further connected to the reactor 10, the reactor 10 is further connected to the alkaline washing bottle 13, and the end of the alkaline washing bottle 13 is connected to the venting device 14; wherein, the mixer 4 and the preheater 6 A pressure gauge 5 is arranged in between, a heating furnace 7 is arranged outside the preheater 6; a sampling point 8 is arranged between the preheater 6 and the reactor 10; an adsorbent 11 is arranged inside the reactor 10, A temperature measuring point 9 is arranged outside the reactor 10 , and a sampling point 12 is arranged between the reactor 10 and the alkaline washing bottle 13 .

(1) Operation steps of the evaluation device

The adsorbent to be tested is crushed into a specified particle size, filled in the reactor, the device is started, and the temperature is started. After the temperature rises to the specified value, adjust the flow of various gases according to the provisions of the raw gas composition table. After the gas enters the reactor, analyze the sulfur dioxide content in the feed gas and the tail gas according to the prescribed method at regular intervals. When the sulfur dioxide concentration in the tail gas is higher than 100 mg/ ^m3 , stop the reaction and record the gas volume passing through the adsorbent.

3. Sulfur capacity analysis method

(1) Analysis of feed gas and tail gas components

The composition of sulfide in the outlet gas of the fixed bed reactor was detected using gas chromatography equipped with a TCD detector. At the same time, GB/T35212.1 "Gas and Solution Analysis and Desulfurization, Decarbonization and Sulfur Recovery Analysis and Evaluation Method in Natural Gas Treatment Plant Part 1: Gas and Solution Analysis" was used to analyze the content of sulfur dioxide in the raw gas.

(2) Calculation method

The _formula for calculating the sulfur capacity (as SO2) of a sulfur dioxide sorbent is as follows:

η——sulfur capacity, in grams per gram (g/g);

Wherein, C _{feed gas} and C _{tail gas} are respectively the mole fraction of sulfur dioxide (unit is %);

V is the volume (unit is L) of the feed gas passing through the sulfur dioxide adsorbent;

64 is the molar mass of sulfur dioxide (unit is g/mol);

22.4 is the molar volume of sulfur dioxide (unit is L/mol) g/mol;

M _sorbent is the mass (in g) of the sulfur dioxide sorbent.

The test results are shown in Table 2.

Table 2 The adsorption sulfur capacity of the sulfur dioxide adsorbents provided in Example 1-Example 4

It can be seen that the sulfur dioxide adsorbent prepared by using the preparation method provided in the embodiment of the present invention has a sulfur capacity that greatly exceeds that of the sulfur dioxide adsorbent provided by the prior art. In addition, the main components of the sulfur dioxide adsorbent provided by the embodiment of the present invention are all common and cheap industrial raw materials, and the cost is greatly reduced compared with the prior art.

The specific embodiments described above further describe the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Within the scope of protection, any modification or equivalent replacement made within the spirit and principle of the present invention, all technical solutions and improvements that do not depart from the spirit and scope of the present invention, shall be covered within the scope of the claims of the present invention. Inside.

Claims

A preparation method of sulfur dioxide adsorbent, wherein, the preparation method comprises the following steps:

(1) iron salt, alkali metal salt are dissolved in water, obtain mixed salt solution, and the mass ratio of described iron salt and described alkali metal salt is (3-100): 1;

(2) mixing alkaline earth metal substance, binder and auxiliary agent with described mixed salt solution to obtain intermediate material;

(3) Kneading and extruding the intermediate material, and sequentially drying and calcining to obtain the sulfur dioxide adsorbent.
The preparation method according to claim 1, wherein, in step (1), the mass ratio of the iron salt to the alkali metal salt is (3-30): 1, more preferably (3-10): 1 , more preferably (3-5):1, more preferably 4:1.
The preparation method according to claim 1 or 2, wherein, in step (1), the iron salt is selected from the group consisting of ferric nitrate, ferrous nitrate, ferric sulfate, ferrous sulfate, ferric chloride and ferrous chloride One or a combination of two or more.
The preparation method according to any one of claims 1-3, wherein, in step (1), the iron salt is selected from one or more of ferric nitrate, ferrous nitrate, ferric sulfate and ferric chloride The combination of ferrous nitrate and ferric sulfate is preferably one or a combination of both, more preferably ferrous nitrate.
The preparation method according to any one of claims 1-4, wherein, in step (1), the alkali metal salt is selected from one or both of sodium chloride, sodium sulfate, potassium chloride and potassium sulfate combination of the above.
The preparation method according to any one of claims 1-5, wherein, in step (1), the alkali metal salt is selected from one or a combination of potassium chloride and sodium sulfate, preferably chloride Potassium.
The preparation method according to claim 1, wherein, in step (2), the mass ratio of the alkaline earth metal-containing substance to the auxiliary agent is (25-50):1, preferably (30-45):1 , more preferably 44:1.
The preparation method according to claim 1, wherein, in step (2), the alkaline earth metal-containing substance is selected from one or a combination of two calcium-containing substances and magnesium-containing substances.
The preparation method according to claim 8, wherein, in step (2), the calcium-containing material is selected from one or a combination of two or more of calcium oxide, calcium hydroxide and calcium carbonate.
The preparation method according to claim 8, wherein, in step (2), the calcium-containing substance is selected from one or a combination of calcium oxide and calcium carbonate.
The preparation method according to any one of claims 8-10, wherein, in step (2), the magnesium-containing material is selected from one or both of magnesium oxide, magnesium hydroxide, magnesium carbonate and basic magnesium carbonate more than one combination.
The preparation method according to any one of claims 8-11, wherein, in step (2), the magnesium-containing material is selected from one or a combination of magnesium hydroxide and basic magnesium carbonate, preferably from magnesium hydroxide.
The preparation method according to claim 1, wherein, in step (2), the mass ratio of the binder to the auxiliary agent is (3-35): 1, preferably (10-35): 1, more preferably 30:1.
The preparation method according to any one of claims 1-13, wherein, in step (2), the binder is selected from boehmite, pseudo-boehmite, aluminum hydroxide, sodium silicate, water One or a combination of two or more of glass and cement.
The preparation method according to any one of claims 1-14, wherein, in step (2), the binder is selected from one or both of pseudo-boehmite, cement, water glass and aluminum hydroxide A combination of more than one, preferably one or a combination of two selected from cement and water glass, more preferably from cement.
The preparation method according to any one of claims 1-15, wherein, in step (2), the auxiliary agent is selected from one or both of saffron powder, carboxymethyl cellulose, polyvinyl alcohol and activated carbon powder A combination of more than one is preferably selected from one or a combination of activated carbon powder and carboxymethyl cellulose, more preferably activated carbon powder.
The preparation method according to any one of claims 1-16, wherein, in step (2), the temperature of the calcination treatment is 400°C-600°C, preferably 400°C-500°C, more preferably 400°C.
The preparation method according to any one of claims 1-17, wherein, in step (2), the calcination treatment time is 1h-10h, more preferably 4h-10h, further preferably 10h.
The sulfur dioxide adsorbent prepared by the preparation method of any one of claims 1-18.
The preparation method of the sulfur dioxide adsorbent according to any one of claims 1-18 or the application of the sulfur dioxide adsorbent according to claim 19 in the high temperature adsorption of sulfur dioxide.