Synergistic removal of Hg from pyrolysis gas of organic solid waste 0 Preparation method of carbon material adsorbent for H2S and HCl

Abstract

The invention discloses a method for synergistically removing Hg from pyrolysis gas of organic solid waste. 0 The invention relates to a method for preparing a carbon material adsorbent for pyrolysis of organic solid waste. The method comprises: firstly, polymethacrylate-polydimethylaminoethyl methacrylate is used as a template and a surfactant, and is fully dissolved and mixed with sodium alginate, agar, carrageenan and a phosphoric acid solution of a certain concentration in different mixing ratios to obtain a sodium alginate-agar-carrageenan mixed solution; then, Sn is added to the mixture. 4+ , Cu 2+ The salt solution is added dropwise to the mixed solution for cross-linking to prepare a spherical particle aerogel loaded with phosphorus-doped metal ions; finally, the aerogel is calcined and carbonized under N2 conditions to obtain a carbon material adsorbent. ‑1 , synergistic removal of Hg from pyrolysis gas of organic solid waste at 30℃ 0 , H2S and HCl with excellent removal efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of organic solid waste pyrolysis, and in particular to a method for synergistically removing Hg from organic solid waste pyrolysis gas. 0 , H 2 A method for preparing a carbon material adsorbent for sulfur and HCl. Background Art

[0002] Organic solid waste mainly includes agricultural organic waste, industrial organic waste and urban domestic waste. Sulfur and chlorine are mainly found in waste plastics, waste rubber, fabrics and kitchen waste, while mercury mainly comes from waste electronic products, printed products and waste batteries. During the pyrolysis and gasification process of organic solid waste, the above elements will enter the fuel gas in the form of gaseous pollutants. Gaseous sulfur mainly includes organic sulfur (COS, CS 2 , CHSH, etc.) and inorganic sulfur (H 2 S); gaseous chlorine mainly exists in the form of HCl, and also includes a small amount of organic chlorine such as chlorobenzene and chlorophenol, as well as metal chloride salts. Both gaseous sulfur and gaseous chlorine will accelerate the corrosion of metal pipeline equipment, shorten its service life, and generate SO during combustion. 2 and dioxin pollutants, which can easily lead to catalyst poisoning during catalytic processing. Gaseous mercury is highly toxic and bioaccumulative, and enters the atmosphere during gas combustion, causing great harm to human life and the environment.

[0003] Single sodium alginate carbon aerogels have some disadvantages: (1) low mechanical strength: this may lead to wear, breakage or deformation of the particles during use, reducing the durability of the adsorption performance; (2) limited adsorption capacity: although aerogel particles have a large specific surface area, their adsorption capacity is still limited by the local diffusion of the substance and the surface area availability.

[0004] The research reports on sodium alginate carbon aerogel in the prior art are as follows:

[0005] Application No. 202310832697.8 discloses a three-dimensional silver-based composite aerogel and its preparation method and application. Poly(acrylamide-co-acrylic acid) / sodium alginate carbon aerogel is prepared by sintering, and then a three-dimensional silver-based composite aerogel with high specific surface area and high catalytic activity is prepared by in-situ deposition using silver nitrate as a precursor solution. Application No. 201710607964.6 discloses an ultra-light three-dimensional hierarchical pore structure carbon aerogel material with excellent hydrophobicity and lipophilicity. Edible natural biopolymers are used as biomass carbon sources, and electrolyte salts are combined with structural shrinkage that inhibits the pyrolysis of biomass carbon sources to prepare three-dimensional hierarchical pore structure carbon aerogels. Application No. 202311141193.8 discloses a positive electrode material and a preparation method thereof, which utilizes a double-helix structured biomass material to cross-link transition metal elements to form a hydrogel, and then utilizes the hydrogel to prepare a metal sulfide (MxSy) nanostructure and a hierarchical porous carbon aerogel (CAs). Metal sulfide is in situ grown in the porous carbon aerogel, achieving controllable chemical reconstruction and chemical adsorption.

[0006] The above-mentioned prior art demonstrates the use of seaweed extract as a carrier to make three-dimensional porous materials for capacitors, electrode materials, adsorbents and catalysts, etc. However, there are still some problems, such as the use of a single seaweed extract and a non-metal-loaded adsorbent cannot provide more metal loading sites; the adsorbent material also has a small specific surface area and uneven pore distribution, which cannot fully utilize the adsorption capacity of the carbon material, resulting in an unsatisfactory removal effect for pollutants, etc.

[0007] This shows that the prior art needs to be further improved. Summary of the invention

[0008] The purpose of the present invention is to provide a method for synergistically removing Hg from pyrolysis gas of organic solid waste. 0 , H 2 Preparation method of carbon material adsorbent of S and HCl, which can synergistically remove Hg from organic solid waste pyrolysis gas under the conditions of temperature 30°C and high space velocity 0 , H 2 S and HCl, and the removal efficiency is excellent.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A synergistic removal of Hg from pyrolysis gas of organic solid waste 0 , H 2 The preparation method of the carbon material adsorbent for sulfur and HCl comprises the following steps in sequence:

[0011] Step 1, using polymethacrylate-polydimethylaminoethyl methacrylate as a template and a surfactant, respectively dissolving and mixing with sodium alginate, agar, carrageenan and a phosphoric acid solution of a certain concentration in different mixing ratios, stirring at 70-90° C. for 3-8 hours to obtain a sodium alginate-agar-carrageenan mixed solution;

[0012] Step 2: Use the reverse drop method to add Sn 4+ , Cu 2+ A sodium alginate-agar-carrageenan mixture is dripped into a saline solution to prepare phosphorus-doped metal ion-loaded spherical aerogels by cross-linking;

[0013] Step 3, carbonizing the phosphorus-doped metal ion-loaded spherical aerogel under a nitrogen atmosphere to obtain a carbon material adsorbent;

[0014] The carbon material adsorbent is placed in a fixed bed reactor under the condition of passing simulated gas and setting the air velocity to 40000h -1 , Hg0, H in the pyrolysis gas of organic solid waste at 30℃ 2 S and HCl are removed;

[0015] The simulated gas includes 35% CH 4 , 20% CO, 35% H 2 and 10% of three pollutants, namely H 2 S, HCl, Hg 0 , H 2 The concentration of S is 100 ppm, the concentration of HCl is 200 ppm, and the concentration of Hg 0 The concentration is 60 μg / m 3 .

[0016] The above-mentioned method can be used to synergistically remove Hg from the pyrolysis gas of organic solid waste. 0 , H 2 The invention discloses a method for preparing a carbon material adsorbent for sulfur and HCl. In step 1, the mass ratio of sodium alginate, agar and carrageenan is 1:0.25-1:0.25-1; the mass concentration of sodium alginate-agar-carrageenan in the mixed solution is 0.5%-5%; and the concentration of the phosphoric acid solution is 15 mol / L.

[0017] The above-mentioned method can be used to synergistically remove Hg from the pyrolysis gas of organic solid waste. 0 , H 2 The preparation method of the carbon material adsorbent for sulfur and HCl comprises the following steps: in step 1, polymethacrylate-polydimethylaminoethyl methacrylate accounts for 1-3% of the total mass of sodium alginate, agar and carrageenan.

[0018] The above-mentioned method can be used to synergistically remove Hg from the pyrolysis gas of organic solid waste. 0, H 2 Preparation method of carbon material adsorbent for S and HCl, wherein in step 2, Sn 4+ , Cu 2+ The loading amount of metal ions in the salt solution is not less than 50% of the total mass of the carbon material adsorbent, wherein the mass ratio of the two metals is 1:1; the mass ratio of sodium alginate, agar and carrageenan is 1:1:1.

[0019] The above-mentioned method can be used to synergistically remove Hg from the pyrolysis gas of organic solid waste. 0 , H 2 The preparation method of the carbon material adsorbent for S and HCl, in step 3, the carbonization temperature is 500-700°C, and the carbonization time is 2h; after carbonization, Sn and Cu oxides are generated, and after contacting with the simulated gas, the Sn and Cu oxides adsorb and catalyze HCl and H 2 S, the generated product is used as adsorbed Hg 0 active sites, eventually generating SnCl 4 、SnS 2 , CuCl 2 ,CuS,HgCl 2 , HgCl, HgS and H 2 O.

[0020] Another object of the present invention is to provide a method for synergistically removing Hg from pyrolysis gas of organic solid waste. 0 , H 2 The carbon material adsorbent for S and HCl is prepared by the above-mentioned preparation method, and the carbon material adsorbent is a shell structure.

[0021] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0022] (1) The present invention selects to use a carbon aerogel mixed with sodium alginate, agar and carrageenan as an adsorbent carrier, wherein in the process of forming a gel, metal ions are chelated with the sulfate groups on agar and carrageenan, and water molecules are hydrogen-bonded with the hydroxyl groups on the agar and carrageenan molecules, thereby forming a stable "double helix" structure to bind more metal ions and generate more active sites for adsorbing gaseous pollutants containing sulfur, chlorine and mercury elements, thereby standing out in terms of cost-effectiveness and removal effect.

[0023] (2) The present invention adds polymethacrylate-polydimethylaminoethyl methacrylate as a template to the mixture of sodium alginate, agar and carrageenan, and the template is decomposed at high temperature during the subsequent carbonization process, leaving a carbon material adsorbent with a large specific surface area and multiple pore sizes, which has an adsorption effect that cannot be achieved by existing adsorbents. In addition, polymethacrylate-polydimethylaminoethyl methacrylate can also be used as a surfactant to reduce the surface tension of the metal ion solution when making gel balls, thereby obtaining gel balls with more regular shapes and more uniform internal structures.

[0024] (3) In the process of preparing the sodium alginate-agar-carrageenan mixture, phosphoric acid is added to achieve doping of phosphorus element and form phosphate groups, thereby promoting an increase in the number of active sites.

[0025] (4) The present invention uses two metal oxides, Sn and Cn, to synergistically remove pollutants, which can improve the water resistance of the adsorbent and promote the generation of surface active oxygen and oxygen vacancies.

[0026] (5) The present invention adopts the reverse dropping method to add Sn 4+ , Cu 2+ A sodium alginate-agar-carrageenan mixed solution is dripped into a salt solution, and phosphorus-doped metal ion-loaded spherical aerogels are made by cross-linking. The reverse dripping method can wrap the metal solution inside the gel film when chelating with metal ions, and the metal ions diffuse from the inside to the outside, thereby improving the strength of the gel sphere, increasing the chelation amount of the sodium alginate-agar-carrageenan mixed gel and metal ions, and improving the adsorption effect of the aerogel. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings:

[0028] Figure 1 This is an electron microscope image of the carbon material adsorbent prepared in Example 1 of the present invention.

[0029] Figure 2 When the mass ratio of sodium alginate: agar: carrageenan is 1:1:1, 3:1:1, 2:2:1, 1:2:2, 1:1:3, the adsorbent has a good affinity for Hg. 0 Removal efficiency and removal amount diagram.

[0030] Figure 3 When the mass ratio of sodium alginate: agar: carrageenan is 1:1:1, 3:1:1, 2:2:1, 1:2:2, 1:1:3, the adsorbent has a high affinity for H 2 The removal efficiency and removal amount of S.

[0031] Figure 4The removal efficiency and removal amount of HCl by the adsorbent when the ratio of sodium alginate: agar: carrageenan is 1:1:1, 3:1:1, 2:2:1, 1:2:2, and 1:1:3 (mass ratio). DETAILED DESCRIPTION

[0032] The present invention proposes a method for synergistically removing Hg from pyrolysis gas of organic solid waste. 0 , H 2 Preparation method of carbon material adsorbent for S and HCl In order to make the advantages and technical solutions of the present invention clearer and more specific, the present invention is further described below in conjunction with specific embodiments.

[0033] The raw materials described in the present invention can all be purchased through commercial channels.

[0034] The evaluation method of the carbon material adsorbent prepared by the present invention is carried out according to the following steps:

[0035] Detection method: A fixed bed reactor was used, and the outlet HCl and H were detected by gas chromatograph (GC-9720Plus) and mercury analyzer (LumexRA-915). 2 S and Hg 0 concentration.

[0036] Experimental conditions: airspeed 40000h -1 , the temperature is 30℃. The simulated gas composition is: 35% CH 4 , 20% CO, 35% H 2 , 100ppmH 2 S, 200ppmHCl and 60μg / m 3 Hg 0 and balance nitrogen. A saturator system was used to supply water and the water content was expressed as relative humidity (RH). A water bath heated Hg permeation tube provided Hg in the simulated gas. A mass flow controller was used to control the total flow rate to 1 L / min.

[0037] Evaluation method: The HCl and H 2 The desulfurization and dechlorination efficiency can be obtained by the change of S concentration. The calculation method is as follows:

[0038]

[0039] In formula (1), C in represents the HCl and H before adsorption reaction 2 S concentration, mg / m 3 ;

[0040] C out It means that after adsorption reaction, HCl and H 2 S concentration, mg / m 3 ;

[0041] Capacity indicates the amount of Hg adsorbed per unit mass of the adsorbent. 0 , H 2 The mass of S and HCl is calculated as follows:

[0042]

[0043] In formula (2), C in represents the HCl and H before adsorption reaction 2 S concentration, mg / m 3 ;

[0044] C out It means that after adsorption reaction, HCl and H 2 S concentration, mg / m 3 ;

[0045] t represents the adsorption reaction time, min;

[0046] m represents the mass of the adsorbent, g;

[0047] The technical solution of the present application is further described in detail below in conjunction with the accompanying drawings.

[0048] The main technical concept of the present invention is: using metal Cu and Sn as loaded metals for synergistic treatment can improve the water resistance of carbon material adsorbents and promote the generation of surface active oxygen and oxygen vacancies. The carbon material adsorbent doped with phosphorus and added with polymethacrylate-polydimethylaminoethyl methacrylate template has the characteristics of adjustable pore size, high specific surface area and increased active sites. Polymethacrylate-polydimethylaminoethyl methacrylate can also be used as a surfactant to reduce the surface tension of metal ion solutions when making gel balls, thereby obtaining gel balls with more regular shapes and more uniform internal structures. Sodium alginate with abundant material sources and carrageenan and agar with more active sites are selected to chelate with more metal ions during the gelation process. Using polymethacrylate-polydimethylaminoethyl methacrylate template to prepare carbon aerogel adsorbents with adjustable pore size and abundant pores, the obtained Hg in the pyrolysis gas of organic solid waste can be obtained. 0 , H 2 Better removal of S and HCl.

[0049] The present invention will be further described below in conjunction with specific embodiments.

[0050] Embodiment 1:

[0051] The present invention synergistically removes Hg from organic solid waste pyrolysis gas 0 , H 2 The preparation method of the carbon material adsorbent for sulfur and HCl specifically comprises the following steps:

[0052] Step 1: Pre-treat sodium alginate, agar and carrageenan: weigh 1.33 g of sodium alginate, 1.33 g of agar and 1.33 g of carrageenan and add them to 200 ml of distilled water. Heat the mixture to 90°C, add 100 ml of 15 mol / L phosphoric acid solution, and stir at 90°C with a magnetic stirrer for 3 hours;

[0053] Take 1 ml of tetrahydrofuran, dissolve 0.05 g of polymethacrylate-polydimethylaminoethyl methacrylate in tetrahydrofuran with high solubility, then slowly add 1 ml of deionized water to the solution to produce micelle aggregation, and add the solution to 7 ml of deionized water to inhibit aggregation. Add distilled water to the total volume of the solution to 400 ml, stir at 80 ° C for 1 hour, so that the mass ratio of sodium alginate, agar and carrageenan in the solution is 1:1:1, and obtain a sodium alginate-agar-carrageenan mixed solution;

[0054] Step 2: Take 1gSnCl 4 and 1.72 gCu(NO 3 ) 2 ·3H 2 O, dissolved in distilled water to prepare a mixed metal salt solution with a mass ratio of Sn:Cu of 1:1. Using the reverse drop method, the stirred SnCl 4 and Cu(NO 3 ) 2 ·3H 2 A mixed solution of equal mass fraction of O was dropped into a mixed solution of sodium alginate-agar-carrageenan to prepare phosphorus-doped metal ion-loaded spherical aerogels;

[0055] The third step is to repeatedly wash the hydrogel with tetrahydrofuran and deionized water to remove excess polymethacrylate-polydimethylaminoethyl methacrylate and metal ions. After washing six times, the gel balls are placed in a freeze dryer and frozen for 24 hours. Then, the aerogel is vacuum freeze-dried at -40°C and 10Pa to obtain the aerogel. The obtained aerogel is then placed in a tubular furnace at 100% N 2 The metal oxide-loaded carbon material adsorbent with controllable pore size was prepared by carbonization for 2 h under atmosphere and 600 °C (heating rate was set to 5 °C / min).

[0056] The electron microscope image of the carbon material adsorbent prepared in this example is as follows Figure 1 As shown, from Figure 1 It can be seen that the surface of the carbon material adsorbent material is smooth, and the nanoparticles are visible aggregated, showing a three-site network structure with higher pore abundance.

[0057] The phosphorus-doped metal oxide-supported carbon material adsorbent with controllable pore size prepared in this example was subjected to an experiment under high air velocity conditions: air velocity 40000h -1 , the temperature is 30℃. The simulated gas composition is: 35% CH 4 , 20% CO, 35% H 2 , and 10% of a mixed gas comprising 200 ppm H 2 S, 100ppmHCl and 60μg / m 3 Hg 0 and balance nitrogen. A saturator system was used to supply water and the water content was expressed as relative humidity (RH). A water bath heated Hg permeation tube provided Hg in the simulated gas. A mass flow controller was used to control the total flow rate to 1 L / min. The desulfurization efficiency was 96.56%, the dechlorination efficiency was 95.71%, and the mercury removal efficiency was 97.23%.

[0058] Embodiment 2:

[0059] The difference from Example 1 is that: in the first step, the mass ratio of sodium alginate, agar and carrageenan is 3:1:1;

[0060] After testing, the desulfurization efficiency was 86.33%, the dechlorination efficiency was 83.67%, and the mercury removal efficiency was 91.47%.

[0061] Embodiment 3:

[0062] The difference from Example 1 is that: in the first step, the mass ratio of sodium alginate, agar and carrageenan is 2:2:1;

[0063] After testing, the desulfurization efficiency was 84.48%, the dechlorination efficiency was 85.33%, and the mercury removal efficiency was 86.27%.

[0064] Embodiment 4:

[0065] The difference from Example 1 is that: in the first step, the mass ratio of sodium alginate, agar and carrageenan is 1:2:2;

[0066] After testing, the desulfurization efficiency was 92.59%, the dechlorination efficiency was 94.78%, and the mercury removal efficiency was 95.35%.

[0067] Embodiment 5:

[0068] The difference from Example 1 is that: in the first step, the mass ratio of sodium alginate, agar and carrageenan is 1:1:3;

[0069] After testing, the desulfurization efficiency was 94.78%, the dechlorination efficiency was 92.59%, and the mercury removal efficiency was 94.44%.

[0070] The Hg 0 The removal efficiency of H 2 The removal efficiency of S and HCl are as follows: Figure 2 , Figure 3 , Figure 4 As shown. Figure 2 , Figure 3 and Figure 4 It can be seen that when the ratio of sodium alginate, agar and carrageenan is 1:1:1, the adsorbent has a good effect on Hg 0 , HCl and H 2 S maintains high removal efficiency for the longest time and has the largest total adsorption amount, resulting in the best removal effect.

[0071] Embodiment 6:

[0072] The difference from Example 1 is that in the first step, the stirring temperature of sodium alginate, agar, carrageenan and phosphoric acid is 70°C.

[0073] The carbonization temperature in the third step is 500°C.

[0074] Comparative Example 1:

[0075] Differences from Example 1:

[0076] The gel particles are not prepared by dropping a mixture of sodium alginate and carrageenan into a metal solution, but the mixture of sodium alginate, agar and carrageenan is directly mixed with the metal solution and cut into small pieces after solidification.

[0077] The specific preparation steps are:

[0078] Step 1: Pre-treat sodium alginate, agar and carrageenan: weigh 1.33 g of sodium alginate, 1.33 g of agar and 1.33 g of carrageenan and add them to 200 ml of distilled water. Heat the mixture to 90°C, add 100 ml of 15 mol / L phosphoric acid solution, and stir at 90°C with a magnetic stirrer for 3 hours;

[0079] Take 1 ml of tetrahydrofuran, dissolve 0.05 g of polymethacrylate-polydimethylaminoethyl methacrylate in tetrahydrofuran with high solubility, then slowly add 1 ml of deionized water to the solution to produce micelle aggregation, and add the solution to 7 ml of deionized water to inhibit aggregation. Add distilled water to the total volume of the solution to 400 ml, stir at 80 ° C for 1 hour, so that the mass ratio of sodium alginate, agar and carrageenan in the solution is 1:1:1, and obtain a sodium alginate-agar-carrageenan mixed solution;

[0080] Step 2: Take 1gSnCl 4 and 1.72 gCu(NO 3 )2 ·3H 2 O, dissolved in distilled water to prepare a mixed metal salt solution with a mass ratio of Sn:Cu of 1:1. Using the reverse drop method, directly add the stirred SnCl 4 and Cu(NO 3 ) 2 ·3H 2 The mixed solution of equal mass fraction of O is poured into the mixed solution of sodium alginate-agar-carrageenan, cooled and solidified into a whole gel, and then cut into small pieces;

[0081] The third step is to repeatedly wash the hydrogel with tetrahydrofuran and deionized water to remove excess polymethacrylate-polydimethylaminoethyl methacrylate and metal ions. After washing six times, the gel balls are placed in a freeze dryer and frozen for 24 hours. Then, the aerogel is vacuum freeze-dried at -40°C and 10Pa to obtain the aerogel. The obtained aerogel is then placed in a tubular furnace at 100% N 2 The metal oxide-loaded carbon material adsorbent with controllable pore size was prepared by carbonization for 2 h under atmosphere and 600 °C (heating rate was set to 5 °C / min).

[0082] The phosphorus-doped metal oxide-supported carbon material adsorbent with controllable pore size prepared in this example was subjected to an experiment under high air velocity conditions: air velocity 40000h -1 , the temperature is 30℃. The simulated gas composition is: 35% CH 4 , 20% CO, 35% H 2 , and 10% of a mixed gas comprising 200 ppm H 2 S, 100ppmHCl and 60μg / m 3 Hg 0 and balance nitrogen. A saturator system was used to supply water and the water content was expressed as relative humidity (RH). A water bath heated Hg permeation tube provided Hg in the simulated gas. A mass flow controller was used to control the total flow rate to 1L / min. The results showed that the removal efficiency of the three pollutants was reduced, with a desulfurization efficiency of 93.46%, a dechlorination efficiency of 91.35%, and a mercury removal efficiency of 94.30%.

[0083] Comparative Example 2:

[0084] The difference from Example 1 is that no polymethacrylate-polydimethylaminoethyl methacrylate template is added.

[0085] The specific preparation steps are:

[0086] Step 1: Pre-treat sodium alginate, agar and carrageenan: weigh 1.33g of sodium alginate, 1.33g of agar and 1.33g of carrageenan and add them to 200ml of distilled water. Heat the mixture to 90°C, add 100ml of 15mol / L phosphoric acid solution, and stir with a magnetic stirrer at 90°C for 3h. Make the mass ratio of sodium alginate, agar and carrageenan in the solution 1:1:1, and obtain a sodium alginate-agar-carrageenan mixture;

[0087] Step 2: Take 1gSnCl 4 and 1.72 gCu(NO 3 ) 2 ·3H 2 O, dissolved in distilled water to prepare a mixed metal salt solution with a mass ratio of Sn:Cu of 1:1. Using the reverse drop method, the stirred SnCl 4 and Cu(NO 3 ) 2 ·3H 2 A mixed solution of equal mass fraction of O was dropped into a mixed solution of sodium alginate-agar-carrageenan to prepare phosphorus-doped metal ion-loaded spherical aerogels;

[0088] The third step is to repeatedly wash the hydrogel with deionized water to remove excess metal ions. After washing six times, the gel balls are placed in a freeze dryer and frozen for 24 hours. Then, they are vacuum freeze-dried at -40°C and 10Pa to obtain aerogel. The obtained aerogel is then placed in a tubular furnace at 100% N 2 The metal oxide-loaded carbon material adsorbent with controllable pore size was prepared by carbonization for 2 h under atmosphere and 600 °C (heating rate was set to 5 °C / min).

[0089] The phosphorus-doped metal oxide-supported carbon material adsorbent with controllable pore size prepared in this comparative example was tested under high space velocity conditions, and the specific steps were referred to Example 1. The results showed that the removal efficiency of the three pollutants was reduced, the desulfurization efficiency was 89.38%, the dechlorination efficiency was 87.19%, and the mercury removal efficiency was 91.21%.

[0090] Comparative Example 3:

[0091] The difference from Example 1 is that the back dropping method is not adopted.

[0092] Step 1: Pre-treat sodium alginate, agar and carrageenan: weigh 1.33 g of sodium alginate, 1.33 g of agar and 1.33 g of carrageenan and add them to 200 ml of distilled water. Heat the mixture to 90°C, add 100 ml of 15 mol / L phosphoric acid solution, and stir at 90°C with a magnetic stirrer for 3 hours;

[0093] Take 1 ml of tetrahydrofuran, dissolve 0.05 g of polymethacrylate-polydimethylaminoethyl methacrylate in tetrahydrofuran with high solubility, then slowly add 1 ml of deionized water to the solution to produce micelle aggregation, and add the solution to 7 ml of deionized water to inhibit aggregation. Add distilled water to the total volume of the solution to 400 ml, stir at 80 ° C for 1 hour, so that the mass ratio of sodium alginate, agar and carrageenan in the solution is 1:1:1, and obtain a sodium alginate-agar-carrageenan mixed solution;

[0094] Step 2: Take 1gSnCl 4 and 1.72 gCu(NO 3 ) 2 ·3H 2 O, dissolved in distilled water to prepare a mixed metal salt solution with a mass ratio of Sn:Cu of 1:1. The stirred sodium alginate-agar-carrageenan mixture was dripped into the SnCl 4 and Cu(NO 3 ) 2 ·3H 2 O in a mixed solution with equal mass fractions, thereby preparing phosphorus-doped metal ion-loaded spherical aerogel;

[0095] The third step is to repeatedly wash the hydrogel with tetrahydrofuran and deionized water to remove excess polymethacrylate-polydimethylaminoethyl methacrylate and metal ions. After washing six times, the gel balls are placed in a freeze dryer and frozen for 24 hours. Then, the aerogel is vacuum freeze-dried at -40°C and 10Pa to obtain the aerogel. The obtained aerogel is then placed in a tubular furnace at 100% N 2 The metal oxide-loaded carbon material adsorbent with controllable pore size was prepared by carbonization for 2 h under atmosphere and 600 °C (heating rate was set to 5 °C / min).

[0096] The phosphorus-doped metal oxide-supported carbon material adsorbent with controllable pore size prepared in this comparative example was tested under high space velocity conditions, and the specific steps were referred to Example 1. The results showed that the removal efficiency of the three pollutants was reduced, the desulfurization efficiency became 91.17%, the dechlorination efficiency became 87.19%, and the mercury removal efficiency became 89.55%.

[0097] Comparative Example 4:

[0098] The difference from Example 1 is that agar is not added in the first step, and the back dropping method is not adopted in the second step.

[0099] Step 1: Pre-treat sodium alginate and carrageenan: weigh 2g of sodium alginate and 2g of carrageenan and add them to 200ml of distilled water. Heat the mixture to 90°C, add 100ml of 15mol / L phosphoric acid solution, and stir with a magnetic stirrer at 90°C for 3h;

[0100] Take 1 ml of tetrahydrofuran, dissolve 0.05 g of polymethacrylate-polydimethylaminoethyl methacrylate in tetrahydrofuran with high solubility, then slowly add 1 ml of deionized water to the solution to produce micelle aggregation, and add the solution to 7 ml of deionized water to inhibit aggregation. Add distilled water to the total volume of the solution to 400 ml, stir at 80 ° C for 1 hour, so that the mass ratio of sodium alginate and carrageenan in the solution is 1:1, and obtain a sodium alginate-carrageenan mixed solution;

[0101] Step 2: Take 1gSnCl 4 and 1.72 gCu(NO 3 ) 2 ·3H 2 O, dissolved in distilled water to prepare a mixed metal salt solution with a mass ratio of Sn:Cu of 1:1. The stirred sodium alginate-carrageenan mixture was dripped into the SnCl 4 and Cu(NO 3 ) 2 ·3H 2 O in a solution mixed with equal mass fractions, thereby preparing phosphorus-doped metal ion-loaded spherical aerogel;

[0102] The third step is to repeatedly wash the hydrogel with tetrahydrofuran and deionized water to remove excess polymethacrylate-polydimethylaminoethyl methacrylate and metal ions. After washing six times, the gel balls are placed in a freeze dryer and frozen for 24 hours. Then, the aerogel is vacuum freeze-dried at -40°C and 10Pa to obtain the aerogel. The obtained aerogel is then placed in a tubular furnace at 100% N 2 The metal oxide-loaded carbon material adsorbent with controllable pore size was prepared by carbonization for 2 h under atmosphere and 600 °C (heating rate was set to 5 °C / min).

[0103] The phosphorus-doped metal oxide-supported carbon material adsorbent with controllable pore size prepared in this comparative example was tested under high space velocity conditions, and the specific steps were referred to Example 1. The results showed that the removal efficiency of the three pollutants decreased, the desulfurization efficiency became 88.45%, the dechlorination efficiency became 86.23%, and the mercury removal efficiency became 86.90%.

[0104] Parts not described in the present invention can be implemented by referring to the existing technology.

[0105] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit and scope of the present application, appropriate changes and modifications to the above embodiments are within the scope of protection claimed in the present application.

Claims

1. A synergistic method for removing Hg from pyrolysis gas of organic solid waste 0 A method for preparing a carbon material adsorbent for H2S and HCl, characterized in that: The following steps are included in sequence: Step 1, using polymethacrylate-polydimethylaminoethyl methacrylate as a template and a surfactant, respectively dissolving and mixing with sodium alginate, agar, carrageenan and a phosphoric acid solution of a certain concentration in different mixing ratios, stirring at 70-90° C. for 3-8 hours to obtain a sodium alginate-agar-carrageenan mixed solution; Step 2: Use the reverse drop method to add Sn 4+ , Cu 2+ The salt solution is dropped into the sodium alginate-agar-carrageenan mixture to prepare phosphorus-doped metal ion-loaded spherical aerogels by cross-linking; Step 3, carbonizing the phosphorus-doped metal ion-loaded spherical aerogel under a nitrogen atmosphere to obtain a carbon material adsorbent; The carbon material adsorbent is placed in a fixed bed reactor under the condition of passing simulated gas and setting the air velocity to 40000h -1 , Hg in the pyrolysis gas of organic solid waste at 30℃ 0 , H2S and HCl are removed; The simulated gas is in terms of mass percentage Includes: 35% CH4, 20% CO, 35% H2, and 10% of three pollutants, namely H2S, HCl, and Hg 0 , the concentration of H2S is 100ppm, the concentration of HCl is 200ppm, and the concentration of Hg 0 The concentration is 60 μg / m 3 .

2. A method for synergistically removing Hg from pyrolysis gas of organic solid waste according to claim 1 0 A method for preparing a carbon material adsorbent for H2S and HCl, characterized in that: In step 1, the mass ratio of sodium alginate, agar and carrageenan is 1:0.25~1:0.25~1; the mass concentration of sodium alginate-agar-carrageenan in the mixed solution is 0.5%~5%; and the concentration of the phosphoric acid solution is 15 mol / L.

3. A method for synergistically removing Hg from pyrolysis gas of organic solid waste according to claim 1 0 A method for preparing a carbon material adsorbent for H2S and HCl, characterized in that: In step 1, polymethacrylate-polydimethylaminoethyl methacrylate accounts for 1-3% of the total mass of sodium alginate, agar and carrageenan.

4. A method for synergistically removing Hg from pyrolysis gas of organic solid waste according to claim 2 0 A method for preparing a carbon material adsorbent for H2S and HCl, characterized in that: In step 2, Sn 4+ , Cu 2+ The loading amount of metal ions in the salt solution is not less than 50% of the total mass of the carbon material adsorbent, wherein the mass ratio of the two metals is 1:1; the mass ratio of sodium alginate, agar and carrageenan is 1:1:

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5. A method for synergistically removing Hg from pyrolysis gas of organic solid waste according to claim 1 0 A method for preparing a carbon material adsorbent for H2S and HCl, characterized in that: In step 3, the carbonization temperature is 500-700°C and the carbonization time is 2 hours. After carbonization, Sn and Cu oxides are generated. After contacting with the simulated gas, the Sn and Cu oxides adsorb and catalyze HCl and H2S, and the generated products serve as adsorbents for Hg 0 active sites, ultimately generating SnCl4, SnS2, CuCl2, CuS, HgCl2, HgCl, HgS and H2O.

6. A method for synergistically removing Hg from pyrolysis gas of organic solid waste 0 , H2S and HCl carbon material adsorbent, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 5, and the carbon material adsorbent is a shell structure.

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