A method for preparing, applying, and regenerating a modified porous carbon material mercury adsorbent.

Abstract

This invention provides a method for preparing, applying, and regenerating a modified porous carbon material mercury adsorbent, belonging to the field of industrial exhaust gas purification. The preparation method involves dissolving an initiator in a solution A rich in acidic oxygen-containing functional groups to obtain solution B; mixing solution B with a monomer solution rich in acidic oxygen-containing functional groups to obtain an impregnation solution; immersing the porous carbon material in the impregnation solution and draining it; heating the obtained porous carbon material to a first temperature and maintaining it for 3-20 hours, then further heating it to a second temperature and maintaining it for 1-6 hours to obtain the final mercury adsorbent. This mercury adsorbent is used to remove Hg from industrial exhaust gas. 0 The removal of mercury is achieved by heating the modified porous carbon material mercury adsorbent after adsorption to 210-260℃ in an inert or oxygen-deficient atmosphere and maintaining the temperature for 0.5-3 hours at a heating rate of 0.5-5℃ / min. The mercury adsorbent of this invention exhibits significantly improved mercury capture efficiency, with a mercury capture capacity increased by more than 25 times.

Description

Technical Field

[0001] This invention belongs to the field of industrial exhaust gas purification and treatment, and particularly relates to a method for preparing, applying and regenerating a modified porous carbon material mercury adsorbent. Background Technology

[0002] Mercury is a heavy metal pollutant that can damage the nervous system. With rapid economic and social development, the large-scale emission of mercury from industrial waste gases from power plants, steel mills, cement plants, waste incineration plants, and non-ferrous metal smelting plants seriously threatens human health. Mercury removal from industrial waste gases is a primary means of controlling pollution and meeting emission standards.

[0003] Mercury in industrial exhaust gases mainly exists in the form of gaseous mercury (Hg). 0 Combined mercury, mercury attached to particles, Hg 0 Mercury is a difficult and crucial factor in mercury removal due to its high saturated vapor pressure and insolubility. Among numerous mercury removal technologies, carbon adsorption is currently the most mature, but it suffers from problems such as large adsorbent consumption and high regeneration difficulty, hindering large-scale application and necessitating technological upgrades. Modification is an effective way to improve the mercury capture efficiency of adsorbents. Currently, modification of carbon-based adsorbents mainly focuses on sulfur, nitrogen, halogens, and transition metal oxides. Sulfur and halogen-modified adsorbents, inexpensive and readily available, and with high mercury removal efficiency, have received widespread attention. Unfortunately, during regeneration, some sulfur and halogens desorb from the adsorbent surface, leading not only to a decrease in mercury capture efficiency after regeneration but also increasing the difficulty of treating the regenerated exhaust gas. Therefore, developing a green, efficient, easily regenerated, and reusable mercury capture material to achieve green and efficient removal of mercury from industrial exhaust gas is essential.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing, applying, and regenerating a modified porous carbon material mercury adsorbent, in order to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention provides a method for preparing a modified porous carbon material mercury adsorbent, comprising the following steps:

[0008] S1: Add the initiator to solution A, which is rich in acidic oxygen-containing functional groups, and stir thoroughly to dissolve, thus obtaining solution B.

[0009] Optionally, the solute in solution A includes one or more of succinic acid, tartaric acid, citric acid, succinic anhydride, or glutaric acid.

[0010] Preferably, the mass fraction of the solute is 5-40 wt%.

[0011] More preferably, the mass fraction of the solute is 18-30 wt%.

[0012] Optionally, the initiator includes one or more of benzoyl peroxide, diterpenoid peroxide, or methyl ethyl ketone peroxide.

[0013] Preferably, the amount of the initiator added is 0.2-3.0 wt% of the monomer mass fraction.

[0014] More preferably, the amount of the initiator added is 0.6-1.5 wt% of the monomer mass fraction.

[0015] Preferably, the temperature of solution B is controlled to be no higher than 35°C; more preferably, the temperature of solution B is controlled to be no higher than 30°C.

[0016] S2: Mix the solution B with a monomer solution rich in acidic oxygen-containing functional groups to obtain an impregnation solution.

[0017] Furthermore, the solute in the monomer solution includes monomer one and / or monomer two.

[0018] Optionally, the monomer one includes one or more of methacrylic acid, hydroxyethyl acrylate, butyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, or hydroxypropyl methacrylate.

[0019] Optionally, the monomer 2 includes one or more of butenedioic acid, maleic anhydride, pentenedioic acid, itaconic anhydride, citraconic anhydride, or dimethylmaleic anhydride.

[0020] Preferably, the mass fraction of the solute in the monomer solution is 5-25 wt%, and the mass ratio of monomer one to monomer two is 1:0.5-2.5.

[0021] More preferably, the mass fraction of the solute in the monomer solution is 15-25 wt%, and the mass ratio of monomer one to monomer two is 1:1.5-2.5.

[0022] Furthermore, the volume ratio of solution B to the monomer solution rich in acidic oxygen-containing functional groups is 1-5:1.

[0023] Preferably, the volume ratio of solution B to the monomer solution rich in acidic oxygen-containing functional groups is 4:1.

[0024] Preferably, the temperature of the monomer solution and the impregnation liquid is controlled to be no higher than 35°C; more preferably, the temperature of the monomer solution and the impregnation liquid is controlled to be no higher than 30°C. Excessively high impregnation liquid temperature can cause premature polymerization of the monomer.

[0025] S3: Immerse the porous carbon material in the impregnation solution, then remove and drain.

[0026] Furthermore, the porous carbon material includes one or more of coal-based porous carbon materials, bio-based porous carbon materials, activated carbon fibers, or solid waste polymer porous carbon materials. The carbon material can be molded, granular, powdered, or other porous carbon materials with specific geometric shapes. Simultaneously, the carbon material can be fresh or processed waste porous carbon material.

[0027] Preferably, during the soaking process, the temperature of the soaking solution is controlled to be no higher than 35°C, and more preferably, the temperature of the soaking solution is controlled to be no higher than 30°C.

[0028] S4: Heat the porous carbon material obtained in step S3 to the first temperature and maintain it for 3-20 hours, then continue to heat it to the second temperature and maintain it for 1-6 hours to obtain the final product.

[0029] Further, the first temperature is 55-80℃. During this process, some monomers in the impregnation solution within the pores of the porous carbon material are activated and begin to polymerize, while other components in the impregnation solution rich in acidic oxygen-containing functional groups are bound within molecular cages formed through gradual polymerization. Some activated monomers bond to active sites on the surface of the porous carbon material, thereby anchoring the acidic oxygen-containing functional groups to the surface of the porous carbon material. After the above treatment, the acidic oxygen-containing functional groups can stably remain on the surface of the carbon material without detaching during subsequent use and thermal desorption regeneration operations.

[0030] Preferably, the first temperature is 60-70℃, and the holding time is 5-10h.

[0031] Furthermore, the second temperature is 100-150℃. During this process, a small amount of residual monomers accelerate the reaction, thereby achieving deep solidification of acidic oxygen-containing functional groups, while removing water and other impurities from the surface of the mercury adsorbent.

[0032] Preferably, the second temperature is 105-120℃, and the holding time is about 3 hours.

[0033] This invention also provides an application of the modified porous carbon material mercury adsorbent prepared by the above method, for use in removing Hg from industrial exhaust gases. 0 The removal of oxygen in the industrial exhaust gas is described under the following conditions: oxygen concentration of 2-21%, temperature of 50-165℃, and water content of 0-15%.

[0034] Furthermore, the best application conditions are: an oxygen concentration of 6-15% in industrial exhaust gas, a temperature of 90-125℃, and a water content of 2-10%.

[0035] The present invention also provides a method for regenerating the modified porous carbon material mercury adsorbent prepared by the above preparation method, wherein the modified porous carbon material mercury adsorbent after adsorption is heated to 210-260℃ in an inert atmosphere or an oxygen-deficient atmosphere and held for 0.5-3h, with a heating rate of 0.5-5℃ / min.

[0036] Optionally, the inert atmosphere is one or more of nitrogen, argon, water vapor, or carbon dioxide.

[0037] Preferably, the thermal desorption regeneration process is as follows: the temperature is raised to 220-230℃ under a nitrogen atmosphere and held for 1.5h, with a heating rate of 2℃ / min.

[0038] Preferably, the oxygen concentration in the oxygen-deficient atmosphere is no greater than 2.0%.

[0039] Thermal desorption regeneration temperature is a key factor affecting the reusability of mercury adsorbents. If the temperature is too low, it is difficult to achieve the regeneration effect, while if the temperature is too high, it will destroy the structure of acidic oxygen-containing functional groups, resulting in a rapid decrease in its reusability.

[0040] This invention utilizes the catalytic oxidation activity of acidic oxygen-containing functional groups to achieve the oxidation of Hg. 0 The mercury is oxidized and captured, and its relatively weak bonding forces enable thermal desorption and regeneration of the mercury adsorbent at lower temperatures. Therefore, the mercury adsorbent obtained in this invention is more suitable for mercury removal from industrial exhaust gases at lower temperatures, and appropriate oxygen and water concentrations are beneficial for mercury capture.

[0041] The beneficial effects of this invention are as follows:

[0042] 1. The modified porous carbon material of this invention has a significantly improved mercury capture efficiency, with a mercury capture capacity increased by more than 25 times.

[0043] 2. The processing technology is mild and easy to control, requiring only room temperature and low temperature treatment. The reagents used are inexpensive and readily available, and the equipment requirements are low.

[0044] 3. The technical solution of the present invention has broad applicability and is applicable to porous carbon materials from various sources, such as coal-based porous carbon materials, bio-based porous carbon materials, solid waste polymer porous carbon materials, and treated waste porous carbon materials.

[0045] 4. The modified porous carbon material obtained by this invention has a low thermal desorption regeneration temperature, with a thermal regeneration temperature as low as 210℃, which greatly reduces the regeneration energy consumption and the heat resistance requirements of the equipment.

[0046] 5. During the thermal desorption and regeneration process of this invention, there is no release of harmful gases such as sulfur and halogens, which reduces the difficulty of reusing the modified mercury adsorbent. Attached Figure Description

[0047] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0048] Figure 1 The graph shows the temperature-programmed desorption curves of mercury during the thermal desorption and regeneration process of the mercury adsorbent after use in Examples 7 and 6 of this invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Where the proportions of substances in the embodiments are not specified, it should be understood that they can be matched in any proportion. Where the units of proportion of substances are not specified, it should be understood as mass ratios.

[0051] In the following examples and comparative examples, the mercury adsorbent removed mercury from simulated industrial exhaust gas under the following conditions: reaction temperature 110°C, catalyst loading volume 5 mL, simulated gas flow rate 1000 mL / min, and Hg... 0 Concentration 300 μg / m 3 The oxygen concentration is 6.0%, the water content is 5.0%, and nitrogen is used as the balance gas. Real-time monitoring of the simulated exhaust gas outlet Hg... 0 The concentration, when the removal efficiency is less than 90% (outlet Hg) 0 Concentration ≥30μg / m 3 Stop the detection and calculate the mercury capture capacity per unit mass of adsorbent (unit: μg / g) and the average mercury removal efficiency (unit: %).

[0052] Example 1

[0053] A method for preparing modified porous carbon material mercury adsorbent using coal-based granular activated carbon as raw material:

[0054] (1) Prepare an aqueous solution A rich in acidic oxygen-containing functional groups, add an initiator to it, stir thoroughly to dissolve, and obtain solution B. Control the temperature of solution B at 30-32℃. Prepare an aqueous solution of monomer rich in acidic oxygen-containing functional groups, and control the temperature of the monomer aqueous solution at 30-32℃.

[0055] The solute in solution A is composed of succinic acid, tartaric acid, citric acid, succinic anhydride, and glutaric acid in a mass ratio of 1:1:1:1:1, and the total mass fraction of the solute is 30 wt%.

[0056] The initiator is composed of benzoyl peroxide, ditert-pentyl peroxide, and methyl ethyl ketone peroxide in a mass ratio of 1:1:1, and the amount of initiator added is 1.5 wt% of the monomer mass fraction.

[0057] The solute monomer in the monomer aqueous solution consists of two parts: monomer one and monomer two. Monomer one is composed of methacrylic acid, hydroxyethyl acrylate, butyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:1:1:1:1:1. Monomer two is composed of butenedioic acid, maleic anhydride, pentenedioic acid, itaconic anhydride, citraconic anhydride, and dimethylmaleic anhydride in a mass ratio of 1:1:1:1:1:1. The mass ratio of monomer one to monomer two is 1:2, and the total mass fraction of the solute monomer is 20 wt%.

[0058] (2) Mix solution B and monomer solution at a volume ratio of 4:1 to obtain impregnation solution, and control the temperature of impregnation solution to 30-32℃.

[0059] (3) Soak the dried biomass porous carbon material in the impregnation solution for 1 hour, and control the temperature of the impregnation solution to 30-32℃, and then take it out and drain it.

[0060] (4) The treated porous carbon material was heated to 65°C and held for 8 hours, then heated to 110°C and held for 3 hours. After cooling, it was removed to obtain the modified porous carbon material mercury adsorbent.

[0061] The mercury capture performance of the obtained mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0062] Example 2

[0063] A method for preparing modified porous carbon material mercury adsorbent using biomass porous carbon material as raw material:

[0064] (1) Prepare an aqueous solution A rich in acidic oxygen-containing functional groups, add an initiator to it, stir thoroughly to dissolve, and obtain solution B. Control the temperature of solution B at 30℃. Prepare an aqueous solution of monomer rich in acidic oxygen-containing functional groups, and control the temperature of the monomer aqueous solution at 30℃.

[0065] The solute in solution A is composed of citric acid, succinic acid, succinic anhydride, and glutaric acid in a mass ratio of 1:2:2:1, and the total mass fraction of the solute is 5 wt%.

[0066] The initiator is composed of benzoyl peroxide, ditert-pentyl peroxide, and methyl ethyl ketone peroxide in a mass ratio of 1:1:1, and the amount of initiator added is 0.2 wt% of the monomer mass fraction.

[0067] The solute monomer in the aqueous solution consists of two parts: monomer one and monomer two. Monomer one is composed of methacrylic acid, hydroxyethyl acrylate, butyl acrylate, and methyl methacrylate in a mass ratio of 2:1:2:1. Monomer two is composed of butylated oleic acid, maleic anhydride, and pentenedic acid in a mass ratio of 1:1:1. The mass ratio of monomer one to monomer two is 1:0.5, and the total mass fraction of the solute monomer is 25 wt%.

[0068] (2) Mix solution B and monomer solution at a volume ratio of 1:1 to obtain impregnation solution, and control the temperature of impregnation solution at 30℃.

[0069] (3) Soak the dried coal-based granular activated carbon in the impregnation solution for 3 hours, control the temperature of the impregnation solution to 30℃, and then take it out and drain it.

[0070] (4) The treated porous carbon material was heated to 55°C and held for 20 hours, then heated to 150°C and held for 6 hours. It was then cooled and removed to obtain a coal-based modified mercury adsorbent.

[0071] The mercury capture performance of the obtained mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0072] Example 3

[0073] A method for preparing modified mercury adsorbents using waste polymer-based porous carbon materials as raw materials:

[0074] (1) Prepare an aqueous solution A rich in acidic oxygen-containing functional groups, add an initiator to it, stir thoroughly to dissolve, and obtain solution B. Control the temperature of solution B at 35℃. Prepare an aqueous solution of monomer rich in acidic oxygen-containing functional groups, and control the temperature of the monomer aqueous solution at 35℃.

[0075] The solute in solution A is composed of citric acid, succinic anhydride, and glutaric acid in a mass ratio of 1:2:3, and the total mass fraction of the solute is 40 wt%.

[0076] The initiator is composed of benzoyl peroxide and ditert-pentyl peroxide in a mass ratio of 1:1, and the amount of initiator added is 3.0 wt% of the monomer mass fraction.

[0077] The solute monomer in the monomer aqueous solution consists of two parts: monomer one and monomer two. Monomer one is composed of methyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 2:1:1. Monomer two is composed of itaconic anhydride, citraconic anhydride, and dimethylmaleic anhydride in a mass ratio of 1:3:1. The mass ratio of monomer one to monomer two is 1:2.5, and the total mass fraction of the solute monomer is 5 wt%.

[0078] (2) Mix solution B and monomer solution at a volume ratio of 5:1 to obtain impregnation solution, and control the temperature of impregnation solution at 35℃.

[0079] (3) Soak the dried waste polymer-based porous carbon material in the impregnation solution for 0.5 h, control the temperature of the impregnation solution to 35 °C, and then take it out and drain it.

[0080] (4) The treated porous carbon material was heated to 80°C and held for 3 hours, then heated to 100°C and held for 1 hour. After cooling, it was removed to obtain the modified porous carbon material mercury adsorbent.

[0081] The mercury capture performance of the obtained mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0082] Example 4

[0083] A method for preparing modified porous carbon material mercury adsorbent using waste powdered activated carbon as raw material:

[0084] (1) Prepare an aqueous solution A rich in acidic oxygen-containing functional groups, add an initiator to it, stir thoroughly to dissolve, and obtain solution B. Control the temperature of solution B at 28-32℃. Prepare an aqueous solution C rich in acidic oxygen-containing functional groups, and control the temperature of the monomer aqueous solution at 28-32℃.

[0085] The solute in solution A consists of citric acid and succinic acid in a mass ratio of 1:1, and the total mass fraction of the solute is 25 wt%.

[0086] The amount of initiator benzoyl peroxide added is 1.0 wt% of the monomer mass fraction.

[0087] The solute monomer in the monomer aqueous solution consists of two parts: monomer one and monomer two. Monomer one is composed of methacrylic acid and hydroxyethyl acrylate in a mass ratio of 3:1. Monomer two is composed of butenedioic acid and maleic anhydride in a mass ratio of 2:1. The mass ratio of monomer one to monomer two is 1:2, and the total mass fraction of the solute monomer is 12 wt%.

[0088] (2) Mix solution B and monomer solution at a volume ratio of 3:1 to obtain impregnation solution, and control the temperature of impregnation solution to 28-32℃.

[0089] (3) Soak the dried, harmless treated waste powdered activated carbon in the impregnation solution for 1 hour, controlling the temperature of the impregnation solution to 28-32℃, and then take it out and drain it.

[0090] (4) The treated porous carbon material was heated to 70°C and held for 12 hours, then heated to 135°C and held for 6 hours. After cooling, it was removed to obtain the modified powdered carbon material mercury adsorbent.

[0091] The mercury capture performance of the obtained mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0092] Example 5

[0093] A method for preparing modified porous carbon material mercury adsorbent using activated carbon fiber as raw material:

[0094] (1) Prepare an aqueous solution A rich in acidic oxygen-containing functional groups, add an initiator to it, stir thoroughly to dissolve, and obtain solution B. Control the temperature of solution B at 30-35℃. Prepare an aqueous solution C rich in acidic oxygen-containing functional groups, and control the temperature of the monomer aqueous solution at 30-35℃.

[0095] The solute in solution A is composed of succinic acid, succinic anhydride, and glutaric acid in a mass ratio of 3:1:1, and the total mass fraction of the solute is 24 wt%.

[0096] The initiator is composed of benzoyl peroxide, ditert-pentyl peroxide, and methyl ethyl ketone peroxide in a mass ratio of 1:1:2, and the amount of initiator added is 0.5 wt% of the monomer mass fraction.

[0097] The solute monomer in the monomer aqueous solution consists of two parts: monomer one and monomer two. Monomer one is composed of methacrylic acid, hydroxyethyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:1:3. Monomer two is composed of butenedioic acid, maleic anhydride, and dimethylmaleic anhydride in a mass ratio of 1:2:1. The mass ratio of monomer one to monomer two is 1:0.8, and the total mass fraction of the solute monomer is 8 wt%.

[0098] (2) Mix solution B and monomer solution at a volume ratio of 3.5:1 to obtain impregnation solution, and control the temperature of impregnation solution to 30-35℃.

[0099] (3) Soak the dried activated carbon fiber in the impregnation solution obtained in S2 for 3 hours, and control the temperature of the impregnation solution to 30-35℃, and then take it out and drain it.

[0100] (4) The treated porous carbon material was heated to 70°C and held for 16 hours, then heated to 125°C and held for 2 hours. After cooling, it was removed to obtain the modified porous carbon material mercury adsorbent.

[0101] The mercury capture performance of the obtained mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0102] Example 6

[0103] A method for regenerating mercury adsorbents from modified porous carbon materials:

[0104] The mercury adsorbent from Example 1, after undergoing mercury capture performance evaluation, was thermally desorbed and regenerated under the following conditions: The temperature was raised to 210°C and held for 0.5 h under a nitrogen atmosphere at a heating rate of 5°C / min. The regenerated mercury adsorbent was then obtained. The mercury capture performance of the regenerated mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0105] Example 7

[0106] A method for regenerating mercury adsorbents from modified porous carbon materials:

[0107] The mercury adsorbent from Example 1, after mercury capture performance evaluation, was thermally desorbed and regenerated under the following conditions: The temperature was raised to 260°C and maintained for 3 hours in an oxygen-deficient (<2.0%) atmosphere at a heating rate of 0.5°C / min. The regenerated mercury adsorbent was then obtained. The temperature-programmed desorption curve of mercury during the thermal desorption and regeneration process is shown below. Figure 1 As shown in Table 1, the mercury capture performance of the regenerated mercury adsorbent under simulated industrial exhaust gas conditions is a good indicator of the mercury capture performance.

[0108] Comparative Example 1

[0109] A method for preparing modified porous carbon material mercury adsorbent using coal-based granular activated carbon as raw material:

[0110] (1) Prepare an aqueous solution A rich in acidic oxygen-containing functional groups. The solute in solution A is composed of succinic acid, tartaric acid, citric acid, succinic anhydride and glutaric acid in a mass ratio of 1:1:1:1:1, and the total mass fraction of the solute is 30 wt%.

[0111] (2) Soak the dried biomass porous carbon material in solution A for 1 hour, and control the temperature of the soaking solution to 30-32℃, and then take it out and drain it.

[0112] (3) The treated porous carbon material was heated to 65°C and held for 8 hours, then heated to 110°C and held for 3 hours. After cooling, it was removed to obtain the modified porous carbon material mercury adsorbent.

[0113] The mercury capture performance of the obtained mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0114] Comparative Example 2

[0115] A method for preparing modified porous carbon material mercury adsorbent using biomass porous carbon material as raw material:

[0116] (1) Prepare an aqueous solution of monomer rich in acidic oxygen-containing functional groups, add an initiator to it, stir and dissolve it thoroughly to obtain an impregnation solution, and control the temperature of the impregnation solution to 30-32℃.

[0117] The solute monomer in the monomer aqueous solution consists of two parts: monomer one and monomer two. Monomer one is composed of methacrylic acid, hydroxyethyl acrylate, butyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:1:1:1:1:1. Monomer two is composed of butenedioic acid, maleic anhydride, pentenedioic acid, itaconic anhydride, citraconic anhydride, and dimethylmaleic anhydride in a mass ratio of 1:1:1:1:1:1. The mass ratio of monomer one to monomer two is 1:2, and the total mass fraction of the solute monomer is 20 wt%.

[0118] The initiator is composed of benzoyl peroxide, ditert-pentyl peroxide, and methyl ethyl ketone peroxide in a mass ratio of 1:1:1, and the amount of initiator added is 1.5 wt% of the monomer mass fraction.

[0119] (2) Soak the dried biomass porous carbon material in the impregnation solution for 1 hour, and control the temperature of the impregnation solution to 30-32℃, and then take it out and drain it.

[0120] (3) The treated porous carbon material was heated to 65°C and held for 8 hours, then heated to 110°C and held for 3 hours. After cooling, it was removed to obtain the modified porous carbon material mercury adsorbent.

[0121] The mercury capture performance of the obtained mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0122] Comparative Example 3

[0123] A method for regenerating mercury adsorbents using modified porous carbon materials:

[0124] The mercury adsorbent from Example 1, after undergoing mercury capture performance evaluation, was thermally desorbed and regenerated under the following conditions: The temperature was raised to 400°C and maintained for 3 hours under a nitrogen atmosphere at a heating rate of 5°C / min. The regenerated mercury adsorbent was then obtained. The mercury capture performance of the regenerated mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0125] Comparative Example 4

[0126] A method for regenerating mercury adsorbents using modified porous carbon materials:

[0127] The mercury adsorbent from Comparative Example 1, after its mercury capture performance evaluation, was thermally desorbed and regenerated under the following conditions: The temperature was raised to 210℃ under a nitrogen atmosphere and maintained for 3 hours at a heating rate of 5℃ / min. The regenerated mercury adsorbent was then obtained. The mercury capture performance of the regenerated mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0128] Comparative Example 5

[0129] A method for regenerating mercury adsorbents from modified porous carbon materials:

[0130] The mercury adsorbent from Comparative Example 2, after its mercury capture performance evaluation, was thermally desorbed and regenerated under the following conditions: The temperature was raised to 210℃ under a nitrogen atmosphere and maintained for 3 hours at a heating rate of 5℃ / min. The regenerated mercury adsorbent was then obtained. The mercury capture performance of the regenerated mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0131] Comparative Example 6

[0132] The mercury capture performance of the porous carbon material used in Example 1 under simulated industrial exhaust gas conditions without any treatment is shown in Table 1. The porous carbon material after mercury capture performance evaluation was subjected to thermal desorption regeneration under the following conditions: heating to 400℃ and holding for 3 hours in a nitrogen atmosphere at a heating rate of 5℃ / min. The temperature-programmed desorption curve of mercury during the thermal desorption regeneration process is shown in Table 1. Figure 1 .

[0133] Comparative Example 7

[0134] A method for preparing a mercury adsorbent: The difference from Example 1 is that in step (4), the treated porous carbon material is heated to 65°C and kept for 8 hours, and then directly cooled and removed to obtain a modified porous carbon material mercury adsorbent.

[0135] The mercury capture performance of the obtained mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0136] Comparative Example 8

[0137] The mercury adsorbent of Comparative Example 7 was thermally regenerated under the following conditions after mercury capture performance evaluation: the temperature was raised to 210℃ and held for 3 hours under a nitrogen atmosphere at a heating rate of 5℃ / min. The regenerated mercury adsorbent was then obtained. The mercury capture performance of the regenerated mercury adsorbent under simulated industrial exhaust gas conditions is shown in Table 1.

[0138] The results of Examples 1, 6, and Comparative Example 6 all show that the mercury capture performance of the modified mercury adsorbent is improved by more than 25 times, the thermal desorption regeneration temperature is significantly reduced to 210℃, and the mercury capture performance of the regenerated mercury adsorbent is basically the same as that before regeneration.

[0139] The results of Example 1, Comparative Example 1, and Comparative Example 4 all show that, in the absence of bonding anchoring with acidic oxygen-containing functional groups, the initial mercury capture performance of the mercury adsorbent is comparable, but the performance decreases significantly after regeneration.

[0140] The results of Examples 1, 2, and 5 all indicate that the mercury capture performance of the mercury adsorbent is low due to the lack of pre-embedded acidic oxygen-containing functional groups, but the performance of the mercury adsorbent after regeneration is basically the same as that before regeneration.

[0141] The results of Example 6 and Comparative Example 3 show that excessively high regeneration temperatures destroy the acidic oxygen-containing functional groups on the surface of the mercury adsorbent, resulting in a significant decrease in the reusability of the mercury adsorbent after regeneration.

[0142] The results of Examples 1, 7, and 8 all indicate that the acidic oxygen-containing functional groups of the mercury adsorbent that has not undergone secondary heating treatment have not been deeply solidified, resulting in a significant decrease in both initial mercury capture performance and post-regeneration performance.

[0143] Table 1. Results of mercury capture activity detection of the mercury adsorbents obtained in Examples 1-7 and Comparative Examples 1-8.

[0144]

[0145]

[0146] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for producing a modified porous carbon material mercury adsorbent, characterized by, Comprising the following steps: S1: adding an initiator into a solution A rich in acidic oxygen-containing functional groups to fully dissolve, to obtain a solution B; the solute in the solution A comprises multiple of succinic acid, tartaric acid, citric acid, succinic anhydride or glutaric acid; S2: mixing the solution B with a monomer solution rich in acidic oxygen-containing functional groups to obtain an impregnation liquid; The solute of the monomer solution comprises monomer one and monomer two; The monomer one comprises multiple of methacrylic acid, hydroxyethyl acrylate, butyl acrylate, methyl methacrylate, hydroxyethyl methacrylate or hydroxypropyl methacrylate; The monomer two comprises multiple of butenedioic acid, maleic anhydride, pentenedioic acid, itaconic anhydride, citraconic anhydride or dimethyl maleic anhydride; The mass fraction of the solute of the monomer solution is 5-25wt%, and the mass ratio of the monomer one and the monomer two is 1:0.5-2.5; The volume ratio of the solution B to the monomer solution rich in acidic oxygen-containing functional groups is 1-5:1; S3: soaking a porous carbon material in the impregnation liquid and controlling drying; S4: heating the porous carbon material obtained in step S3 to a first temperature and keeping for 3-20h, and then continuously heating to a second temperature and keeping for 1-6h, to obtain a porous carbon material; The first temperature is 55-80℃, and the second temperature is 100-150℃.

2. The production method according to claim 1, characterized by, The temperature of the solution B in step S1, the monomer solution in step S2 and the impregnation liquid in step S3 is controlled to be not higher than 35℃.

3. The preparation method according to claim 2, characterized in that, The temperature of the solution B in step S1, the monomer solution in step S2 and the impregnation liquid in step S3 is controlled to be not higher than 30℃.

4. The method of claim 1, wherein, In step S3, the porous carbon material comprises one or more of coal-based porous carbon material, bio-based porous carbon material, activated carbon fiber or solid waste polymer porous carbon material.

5. The preparation method according to claim 1, characterized in that, In step S1, the mass fraction of the solute in the solution A is 5-40wt%.

6. The preparation method according to claim 5, characterized in that, In step S1, the mass fraction of the solute in the solution A is 18-30wt%.

7. The preparation method according to claim 1, characterized in that, In step S1, the initiator comprises one or more of dibenzoyl peroxide, di-t-amyl peroxide or methyl ethyl ketone peroxide.

8. The preparation method according to claim 7, characterized in that, In step S1, the addition amount of the initiator is 0.2-3.0wt% of the mass fraction of the monomer.

9. The preparation method according to claim 8, characterized in that, In step S1, the addition amount of the initiator is 0.6-1.5wt% of the mass fraction of the monomer.

10. The method of claim 1, wherein, In step S2, the mass fraction of the solute of the monomer solution is 15-25wt%, and the mass ratio of the monomer one and the monomer two is 1:1.5-2.

5.

11. The method of claim 1, wherein, In step S2, the volume ratio of the solution B to the monomer solution rich in acidic oxygen-containing functional groups is 4:

1.

12. The method of claim 1, wherein, In step S4, the first temperature is 60-70℃, and the second temperature is 105-120℃.

13. Use of a modified porous carbon material mercury adsorbent produced by the production process according to any one of claims 1 to 12, characterized in that, Removal of Hg from industrial off-gases 0 ; The application conditions are: the oxygen concentration of the industrial tail gas is 2-21%, the temperature is 50-165℃, and the water content is 0-15%.

14. Use according to claim 13, characterized in that, The application conditions are: the oxygen concentration of the industrial tail gas is 6-15%, the temperature is 90-125℃, and the water content is 2-10%.

15. A method for regenerating a modified porous carbon material mercury adsorbent produced by the method of any one of claims 1-12, comprising: The modified porous carbon material mercury adsorbent after adsorption is heated to 210-260℃ under inert atmosphere or oxygen-poor atmosphere and kept for 0.5-3h, the heating rate is 0.5-5℃ / min; The oxygen concentration in the oxygen-poor atmosphere is not more than 2.0%.

16. The regeneration method according to claim 15, characterized by, The inert atmosphere is nitrogen or argon.

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