Reactor for low-temperature catalytic decomposition of SO2 as well as preparation method and application of reactor

Abstract

The invention provides a reactor for low-temperature catalytic decomposition of SO2 as well as a preparation method and application of the reactor, and belongs to the technical field of air pollution control. The preparation method comprises the following steps: mixing fly ash, porcelain clay, bentonite, a precursor, a pore-forming agent, an adhesive, an adsorbent and water, and sequentially carrying out mixing, mud fermentation, granulation and calcination, so as to form an amorphous porous structure matrix material between ceramics through calcination; carrying out acid leaching on the base material, loading a catalyst, and roasting to obtain a reactor with macroporous and mesoporous structures; a catalytic system with copper and iron as double active centers is established, a catalyst loaded in a macroporous structure forms an open mesoporous or cage group structure, a mesoporous reaction micro-unit integrating complete inelastic collision and adsorption catalysis is established, the number of pre-exponential factors of a sulfide decomposition reaction is increased, the fracture energy of a bond is reduced, the activation energy of decomposition of SO2 is reduced, and the catalytic activity of the sulfide is improved. Low-temperature decomposition and SO2 removal are realized, and the desulfurization efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of air pollution control, and in particular to a reactor for catalytically decomposing SO2 at low temperature, a preparation method thereof, and an application thereof. Background Art

[0002] With the development of industry and the improvement of people's living standards, the thirst for energy is also increasing continuously. SO2 in the flue gas generated by coal combustion and gas combustion has become the main cause of air pollution. Reducing SO2 pollution has become an urgent task in current air environment control. Many flue gas desulfurization processes have been widely used in the treatment of industrial pollution, and they also have important practical significance for the treatment of the tail gas of various boilers and incinerators.

[0003] Currently, the commonly used desulfurization technology method is the ion method. The principle is that SO2 is converted into SO3 at a high temperature (above 300 °C), and reacts with CaO in an aqueous medium to form CaSO4. This method not only requires a relatively high conversion temperature, but also has secondary pollution. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a reactor for catalytically decomposing SO2 at low temperature, a preparation method thereof, and an application thereof. The reactor prepared by the present invention can realize the catalytic decomposition of SO2 at a low temperature (100-130 °C), and has a high desulfurization efficiency.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a preparation method of a reactor for catalytically decomposing SO2 at low temperature, comprising the following steps:

[0007] Mix fly ash, ganzi soil, bentonite, precursor, pore former, binder, adsorbent and water, and then carry out kneading, mud waking fermentation, granulation and calcination in sequence to obtain a matrix material;

[0008] Acid leach the matrix material to obtain a carrier material;

[0009] Impregnate the carrier material with an acidic metal salt solution, and then carry out drying and roasting in sequence to obtain the reactor. The solute of the acidic metal salt solution includes a main active acidic soluble metal salt and a co-active acidic soluble metal salt. The metal elements in the main active acidic soluble metal salt include copper and iron.

[0010] Preferably, based on 100% of the non-aqueous raw materials, the matrix material is prepared from the following non-aqueous raw materials in terms of mass percentage: 40-50% of fly ash, 5-10% of ganzi soil, 5-10% of bentonite, 15-20% of precursor, 10-15% of pore former, 10-15% of binder, and 5-10% of adsorbent.

[0011] Preferably, the molar ratio of copper element to iron element in the main active acid-soluble metal salt is 3-7:2-5.

[0012] Preferably, the granulation results in spherical embryos, and the diameter of the spherical embryos is 20-40 mm.

[0013] Preferably, the calcination temperature is 800-980 °C and the time is 5-20 h.

[0014] Preferably, the roasting temperature is 300-500 °C and the time is 5-8 h.

[0015] The present invention also provides a reactor for low-temperature catalytic decomposition of SO2 prepared by the above-mentioned preparation method.

[0016] Preferably, the reactor has a macropore and mesopore dual structure, the reactor is spherical, with a diameter of 20-40 mm and a specific surface area of 1.00-2.00 m 2 / g.

[0017] Preferably, the number of macropores in the reactor is 1.00×10 11 -2.00×10 11 pieces, the diameter of the macropores is 1000-2000 nm, the number of mesopores is 3.00×10 5 -4.0×10 5 pieces, the diameter of the mesopores is 20-30 nm, the mesopores are loaded with the main active metal oxide, and the number of active sites of the main active metal oxide loaded on the surface of each mesopore is 4.00×10 4 -5.0×10 4 pieces, and the main active metal oxide includes copper oxide and iron oxide.

[0018] The present invention also provides the application of the reactor described in the above technical solution in the low-temperature catalytic decomposition of SO2, and the temperature of the low-temperature catalytic decomposition of SO2 is 100-130 °C.

[0019] The present invention provides a preparation method of a reactor for low-temperature catalytic decomposition of SO2, comprising the following steps: mixing fly ash, ganzi soil, bentonite, precursor, pore-forming agent, binder, adsorbent and water, and then successively carrying out kneading, wake-up mud fermentation, granulation and calcination to obtain a matrix material; acid-leaching the matrix material to obtain a carrier material; impregnating the carrier material with an acidic metal salt solution and then successively carrying out drying and roasting to obtain the reactor, wherein the solute of the acidic metal salt solution includes a main active acid-soluble metal salt and a co-active acid-soluble metal salt, and the metal elements in the main active acid-soluble metal salt include copper and iron.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] During the calcination process of the present invention, a matrix material with an amorphous porous structure between pottery and porcelain is formed. The matrix material is acid-leached, further increasing the number of pores and specific surface area. After loading an acidic metal salt and calcining, a catalyst is formed, obtaining a reactor with macroporous and mesoporous structures, forming a catalytic system with copper and iron as dual active centers. The catalyst loaded in the macropores constitutes an open mesoporous and cage group structure, establishing a macroporous and mesoporous reaction micro-unit integrating complete inelastic collision and adsorption catalysis. The reactor of the present invention increases the pre-exponential factor number of the oxygen sulfide decomposition reaction and reduces the bond breaking energy, reducing the activation energy for decomposing SO2 to 100 - 130 KJ / mol, providing the kinetic conditions for the catalytic reaction to decompose and remove SO2 at 100 - 130 °C. The reaction mechanism is shown in the following formula:

[0022]

[0023] ·O + ·O → O2↑

[0024] During the process of removing SO2, the negative pressure generated by the induced draft in the system makes the catalytic reaction proceed consistently in the positive direction.

[0025] The present invention is an innovative technology for decomposing and removing SO2 at low temperature based on the synergistic catalysis of the dual-component active substances in the porous structure (including macropores and mesopores) of the reactor. The removal efficiency of SO2 in industrial flue gas at low temperature (100 - 130 °C) reaches more than 90%, featuring low desulfurization temperature and high desulfurization efficiency. Moreover, the preparation method of the present invention is simple, the materials are easily available, it is safe in use, storage and transportation, has low cost, long service life, no secondary pollution, and can be fully recycled and reused, etc.

[0026] The present invention also provides a reactor for catalytically decomposing SO2 at low temperature prepared by the preparation method described in the above technical solution. The data of the examples show that through the synergistic effect of the dual-active catalytic system (copper and iron) and the binary porous (macropores, mesopores) and multi-layer void volume structure, SO2 in industrial flue gas is decomposed into S and O2 at low temperature (100 - 130 °C). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of the reactor prepared in Example 1;

[0028] Figure 2 It is a physical diagram of the reactor prepared in Example 1;

[0029] Figure 3 It is a schematic cross-sectional view of the pores of the reactor prepared in Example 1;

[0030] Figure 4 Cross-sectional physical diagram of the pores of the reactor prepared in Example 1;

[0031] Figure 5 Partial schematic diagram of the bed formed by stacking the reactors in the reaction tower for the reactor prepared in Example 1;

[0032] Figure 6 Schematic structural diagram of the device for preparing the reactor in Example 1;

[0033] Figure 7 Schematic external view of the low-temperature desulfurization reaction tower provided in Example 1;

[0034] Figure 8 Schematic structural diagram of the low-temperature desulfurization reaction tower provided in Example 1;

[0035] Figures 1 to 8 In the figure, 1 - reactor; 2 - macropore; 3 - mesopore; 4 - clay kneader; 5 - granulator; 6 - sintering kiln; 7 - air cooler; 8 - reaction kettle; 9 - dryer; 10 - drying machine; 11 - mixer; 12 - ultrafine grinder; 13 - desulfurization tower; 14 - flue gas inlet pipe; 15 - flue gas outlet pipe; 16 - induced draft fan; 17 - chimney direct discharge bypass pipe. Detailed implementation manners

[0036] The present invention provides a method for preparing a reactor for low-temperature catalytic decomposition of SO2, comprising the following steps:

[0037] Mix fly ash, ganzi clay, bentonite, precursor, pore former, binder, adsorbent and water, and then successively carry out kneading, clay retting fermentation, granulation and calcination to obtain a matrix material;

[0038] Acid-leach the matrix material to obtain a carrier material;

[0039] Impregnate the carrier material with an acidic metal salt solution, and then successively carry out drying and calcination to obtain the reactor. The solute of the acidic metal salt solution includes a main active acidic soluble metal salt and a co-active acidic soluble metal salt, and the metal elements in the main active acidic soluble metal salt include copper and iron.

[0040] In the present invention, unless otherwise specified, the raw materials used are commercially available products in the art.

[0041] The present invention mixes fly ash, ganzi clay, bentonite, precursor, pore former, binder, adsorbent and water, and then successively carries out kneading, clay retting fermentation, granulation and calcination to obtain a matrix material.

[0042] In the present invention, based on the non-aqueous raw materials being 100%, the matrix material is preferably prepared from non-aqueous raw materials including the following mass percentages: fly ash 40 - 50%, ganzi clay 5 - 10%, bentonite 5 - 10%, precursor 15 - 20%, pore-forming agent 10 - 15%, binder 10 - 15%, and adsorbent 5 - 10%.

[0043] The non-aqueous raw materials are described in detail below.

[0044] Based on the non-aqueous raw materials being 100%, the matrix material is preferably prepared from fly ash with a mass percentage of 40 - 50%, specifically it can be 40%, 45%, or 50%.

[0045] In the present invention, the mass percentage of SiO2 in the fly ash is preferably 50 - 60%, specifically it can be 50%, 55%, or 60%; the mass percentage of Al2O3 is preferably 20 - 30%, specifically it can be 20%, 25%, or 30%; the mass percentage of MgO is preferably 2 - 5%, specifically it can be 2%, 3%, 4%, or 5%; the mass percentage of GaO is preferably 1 - 4%, specifically it can be 1%, 2%, 3%, or 4%; the mass percentage of K2O is preferably 1 - 3%, specifically it can be 1%, 2%, or 3%; the mass percentage of Na2O is preferably 1 - 3%, specifically it can be 1%, 2%, or 3%; the mass percentage of Fe2O3 is preferably 0.5 - 5%, specifically it can be 0.5%, 1%, 2%, 3%, 4%, or 5%.

[0046] In the present invention, the particle diameter of the fly ash is preferably 0.5 - 300 nm, specifically it can be 0.5, 1, 10, 50, 100, 150, 200, 250, or 300 nm, the specific surface area is preferably 500 m 2 / g or more, and the porosity is preferably 50 - 80%, specifically it can be 50%, 60%, 70%, or 80%.

[0047] In the present invention, the fly ash is preferably the fly ash generated after the combustion of a chain grate boiler with bituminous coal as the main fuel, and it is an inexpensive and easily available environmentally friendly matrix raw material that can be recycled.

[0048] Based on the non-aqueous raw materials being 100%, the matrix material is preferably prepared from ganzi clay with a mass percentage of 5 - 10%, specifically it can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%.

[0049] Based on the non-aqueous raw materials being 100%, the matrix material is preferably prepared from bentonite with a mass percentage of 10 - 15%, specifically it can be 10%, 11%, 12%, 13%, 14%, or 15%.

[0050] Based on 100% of the non-aqueous raw materials, the matrix material is preferably prepared from 10 - 15% by mass of a pore former, specifically it can be 10%, 12%, 14%, or 15%

[0051] In the present invention, the pore former preferably includes one or more of starch, pulverized coal, and carbonate; the pore former forms a porous structure during calcination. During the calcination process, low molecular weight substances in the pore former and the binder volatilize to form a large number of open pores and channels, and nonlinear polymers (such as CMC, starch, epoxy, esters) in the loss on ignition produce carbon precipitation to form a trace carbon layer on the pore surface (the inner and outer surfaces of the reactor).

[0052] In the present invention, the carbonate preferably includes sodium carbonate and / or potassium carbonate.

[0053] Based on 100% of the non-aqueous raw materials, the matrix material is preferably prepared from 10 - 15% by mass of a binder, specifically it can be 10%, 11%, 12%, 13%, 14%, or 15%.

[0054] In the present invention, the binder preferably includes one or more of carboxymethyl cellulose (CMC), flour, and diatomaceous earth.

[0055] Based on 100% of the non-aqueous raw materials, the matrix material is preferably prepared from 10 - 15% by mass of an adsorbent, specifically it can be 10%, 11%, 12%, 13%, 14%, or 15%.

[0056] In the present invention, the adsorbent preferably includes one or more of NiO, Fe2O3, TiO2, and Nb3O5.

[0057] Based on 100% of the non-aqueous raw materials, the matrix material is preferably prepared from 15 - 20% by mass of a precursor, specifically it can be 15%, 16%, 17%, 18%, 19%, or 20%.

[0058] In the present invention, the precursor preferably includes metal oxides. The metal oxides preferably include one or more of CuO, FeO, Fe2O3, CeO2, MoO3, NiO, ZrO, TiO2, and Nb2O5. The precursor can both act as a catalyst and become an anchoring point for loading homogeneous acidic metal salts, improving the adhesion strength between the main catalyst (a catalytic system with dual active centers) and the matrix material, increasing the catalytic activity of the reactor, and extending the service life of the reactor.

[0059] In the present invention, the mixing preferably further includes adding an anti-poisoning agent. Based on the non-aqueous raw materials being 100%, the matrix material is preferably prepared from 5 to 10% by mass of the anti-poisoning agent, specifically it can be 5%, 6%, 7%, 8%, 9% or 10%.

[0060] In the present invention, the anti-poisoning agent preferably includes CeO2 and / or TiO2.

[0061] In the present invention, the adsorbent is preferably dried before use. The drying temperature is preferably 200 to 350 °C, specifically it can be 200, 250, 300 or 350 °C, and the time is preferably 4 to 5 h. The function of drying is to remove moisture, and the drying is carried out in an electric furnace.

[0062] In the present invention, the non-aqueous raw materials are preferably pulverized before use. The particle size after pulverization is preferably 1000 to 2000 mesh, specifically it can be 1000, 1500 or 2000 mesh.

[0063] In the present invention, the mixing time is preferably 3 to 7 h, specifically it can be 3, 4, 5, 6 or 7 h; the function of mixing is to make each component fully and uniformly mixed.

[0064] In the present invention, the mud waking and fermentation are preferably carried out under sealed conditions. The time for mud waking and fermentation is preferably 48 to 60 h, specifically it can be 48, 50, 55 or 60 h.

[0065] In the present invention, the granulation preferably obtains spherical embryos. The diameter of the spherical embryos is preferably 20 to 40 mm, specifically it can be 20, 25, 27, 30, 35 or 40 mm.

[0066] In the present invention, the granulation preferably uses a granulator or manual shaping.

[0067] After obtaining the spherical embryos, the present invention preferably further includes drying the spherical embryos. The drying is preferably natural air drying at room temperature for 48 h or drying at 100 to 120 °C for 2 to 5 h.

[0068] In the present invention, the calcination temperature is preferably 800 to 980 °C, specifically it can be 800, 840, 850, 880, 920, 940 or 980 °C, and the time is preferably 5 to 20 h, specifically it can be 5, 10, 15 or 20 h; a scaling layer will be generated on the surface during the calcination process and removed by subsequent acid leaching.

[0069] In the present invention, the calcination is preferably carried out in air.

[0070] In the present invention, the calcination is preferably carried out in a muffle furnace or a gas furnace.

[0071] After obtaining the matrix material, the matrix material is acid-leached in the present invention to obtain the carrier material.

[0072] In the present invention, the function of the acid leaching is to increase the specific surface area and remove the scaling layer.

[0073] In the present invention, the acid leaching solution used for acid leaching preferably includes a nitric acid solution, and the mass concentration of the nitric acid solution is preferably 20-40%, specifically it can be 20%, 30% or 40%.

[0074] In the present invention, the acid leaching is preferably soaking with equal volume.

[0075] In the present invention, the temperature of the acid leaching is preferably 30-50 °C, specifically it can be 30, 40 or 50 °C, and the time is preferably 3-6 h, specifically it can be 3, 4, 5 or 6 h.

[0076] After the acid leaching is completed, the present invention preferably further includes drying to obtain the carrier material. In the present invention, the temperature of the drying is preferably 100-200 °C, specifically it can be 100, 150 or 200 °C, and the time is preferably 3-5 h, specifically it can be 3, 4 or 5 h.

[0077] After obtaining the carrier material, the carrier material is impregnated with an acidic metal salt solution and then dried and calcined in sequence to obtain the reactor. The solute of the acidic metal salt solution includes a main active acidic soluble metal salt and a co-active acidic soluble metal salt, and the metal elements in the main active acidic soluble metal salt include copper and iron.

[0078] In the present invention, the molar ratio of copper element to iron element in the main active acidic soluble metal salt is preferably 3-7:2-5, specifically it can be 3:2, 1:1, 3:4, 3:5, 3:1, 2:1, 7:3 or 6:5; the main active acidic soluble metal salt forms copper oxide and iron oxide during the calcination process, which are the anchor nodes for loading the main active substance. The copper element and the iron element form the catalytic active sites of the dual active centers. Combining with the porous structure, the catalytic reaction of the reactor is a reactor system integrating secondary step catalysis and adsorption catalysis, which can reduce the activation energy for decomposing SO2 to 100-130 KJ / mol, and decompose SO2 into S and O2 at low temperature (100-130 °C).

[0079] The present invention has no special limitation on the specific type of the main active acidic soluble metal salt. Acidic copper salts and acidic ferrous salts well-known to those skilled in the art can be used, specifically such as copper nitrate, ferrous chloride, ferrous nitrate or ferrous sulfate.

[0080] In the present invention, the metal element in the co-active acid-soluble metal salt preferably includes one or more of Ce, Mo, Ni, Zr, Ti, and Nb. The co-active acid-soluble metal salt preferably forms metal oxides or metal ions during the calcination process, and the metal oxides preferably include one or more of CeO2, MoO3, NiO, ZrO, TiO2, and Nb2O5.

[0081] The present invention has no special limitation on the specific type of the co-active acid-soluble metal salt, and those well-known to those skilled in the art can be used, such as cerium nitrate, zirconium nitrate, nickel nitrate, or niobium nitrate.

[0082] In the present invention, the mass concentration of the acid-soluble metal salt solution is preferably 15-30%, and specifically can be 15%, 20%, 25%, or 30%.

[0083] In the present invention, the mass ratio of the main-active acid-soluble metal salt to the co-active acid-soluble metal salt is preferably 3:2.

[0084] In the present invention, the main-active acid-soluble metal salt and the co-active acid-soluble metal salt are preferably dried and pulverized in sequence, and then the acid-soluble metal salt solution is prepared. In the present invention, the drying temperature is preferably 200-350°C, specifically can be 200, 250, 300, or 350°C, and the time is preferably 4-5 h. The function of drying is to remove the bound water, and the drying is carried out in an electric furnace.

[0085] In the present invention, the particle size after pulverization is preferably 1000-2000 mesh, and specifically can be 1000, 1500, or 2000 mesh.

[0086] The present invention has no special requirement for the specific method of preparing the acid-soluble metal salt solution, and it can be prepared by mixing the main-active acid-soluble metal salt, the co-active acid-soluble metal salt, and water.

[0087] In the present invention, the impregnation is preferably equal-volume immersion.

[0088] In the present invention, the impregnation temperature is preferably 20-40°C, specifically can be 20, 30, or 40°C, and the time is preferably 3-6 h, specifically can be 3, 4, 5, or 6 h.

[0089] After the impregnation is completed, the present invention preferably further includes drying. The drying temperature is preferably 100-200°C, specifically can be 100, 150, or 200°C, and the time is preferably 8-10 h, specifically can be 8, 9, or 10 h.

[0090] In the present invention, the calcination temperature is preferably 300 to 500 °C, specifically it can be 300, 350, 400, 450 or 500 °C, and the time is preferably 5 to 8 h, specifically it can be 5, 6, 7 or 8 h; during the calcination process, copper and iron form a catalyst with dual active centers, and the catalyst is loaded in the macroporous structure to form an open mesoporous and cage group structure, establishing a macroporous and mesoporous reaction micro-unit for integrated non-elastic collision and adsorption catalysis. This reaction unit increases the pre-exponential factor number of the oxygen sulfide decomposition reaction, reduces the bond breaking energy, and reduces the activation energy for decomposing SO2 to 100 to 130 KJ / mol, providing the kinetic conditions for the catalytic reaction to decompose and remove SO2 at 100 to 130 °C.

[0091] In the present invention, the calcination is preferably carried out in an electric furnace.

[0092] In the present invention, the device used in the preparation method preferably includes: a dryer, an ultrafine grinder, a mixer, a clay kneader, a granulator, a sintering furnace, an air cooler, a reaction kettle and a dryer. The mixer is preferably connected to the clay kneader, the clay kneader is preferably connected to the granulator, the granulator is preferably connected to the dryer, the dryer is preferably connected to the sintering furnace, the sintering furnace is preferably connected to the reaction kettle, the reaction kettle is preferably connected to the dryer, the air cooler is connected to the sintering furnace, and the ultrafine grinder is preferably connected to the mixer.

[0093] In the present invention, the mixer is preferably a twin-screw mixer, the clay kneader is preferably a special clay kneader for ceramic production, the granulator is preferably an extruder, and the sintering furnace is preferably an electric high-temperature muffle furnace or a gas furnace.

[0094] The present invention also provides a reactor for low-temperature catalytic decomposition of SO2 prepared by the above-mentioned preparation method.

[0095] In the present invention, the reactor preferably has a binary structure of macropores and mesopores, the reactor is preferably spherical, the diameter is preferably 20 to 40 mm, specifically it can be 20, 26, 30, 35 or 40 mm, and the specific surface area is preferably 1.00 to 2.00 m 2 / g, specifically it can be 1, 1.5 or 2 m 2 / g.

[0096] In the present invention, the number of macropores in the reactor is preferably 1.00×10 11 ~2.00×10 11 pieces, the diameter of the macropores is preferably 1000 to 2000 nm, specifically it can be 1000, 1200, 1400, 1600, 1800 or 2000 nm, and the number of mesopores is preferably 3.00×10 5 ~4.0×105 There are [X] ones. The diameter of the mesopores is preferably 20 - 30 nm, specifically it can be 20, 25 or 30 nm. Part of the main active metal oxide is loaded in the mesopores. The number of active sites of the main active metal oxide loaded in each mesopore is preferably 4.00×10 4 ~5.0×10 4 ones. The main active metal oxide preferably includes copper oxide and iron oxide.

[0097] The present invention also provides the application of the reactor described in the above technical solution in the low-temperature catalytic decomposition of SO2. The temperature of the low-temperature catalytic decomposition of SO2 is 100 - 130 °C, specifically it can be 100, 110, 120 or 130 °C.

[0098] The present invention has no special limitation on the specific application method, and the methods well-known to those skilled in the art can be adopted, specifically such as in a low-temperature desulfurization reaction tower.

[0099] In the present invention, the low-temperature desulfurization reaction tower preferably includes a flue gas inlet pipe, a desulfurization tower, a flue gas outlet pipe, an induced draft fan, a chimney direct discharge bypass pipe and a cut-off valve. The present invention preferably designs the dosage of the reactor, the residence time of the flue gas in the reactor bed layer according to the flue gas flow rate and the concentration of sulfides in the flue gas, and determines the diameter of the catalytic tower, the number of layers and the single-layer height and layout of the reactor bed layer. The reactor bed layer is composed of reactors stacked.

[0100] In the present invention, the reactor bed layer not only includes the binary porous (macropores, mesopores) open structure of the reactor, but also includes the pores between the reactors. The multi-layer void volume of the reactor bed layer (the bed layer void volume formed by multiple reactors, the inner pore volume of the reactor matrix, the mesopore volume of the catalyst) is preferably more than 60%.

[0101] The present invention preferably installs the reactor into the low-temperature desulfurization reaction tower, heats up, and preferably raises the temperature of the reactor and the tower to 100 - 130 °C, specifically it can be 100, 110, 120 or 130 °C. The flue gas flows into the tower body through the flue gas inlet pipe under the action of the induced draft fan and enters the reactor, and the SO2 in the flue gas is catalytically decomposed to generate S and O2. The O2 is discharged through the flue under the action of the induced draft fan, while the S element diffuses into the air with the flue gas emission, and aggregates into 8S atomic aggregates after cooling and falls into the soil or is recycled and reused as sulfur and other industrial raw materials.

[0102] In the present invention, after the reactor is used, it is preferably recycled by physical regeneration or chemical treatment regeneration methods.

[0103] In the present invention, the physical regeneration is preferably grinding to renew the surface of the reactor.

[0104] In the present invention, the chemical treatment regeneration is preferably acid treatment, which removes low-molecular substances (including amines, carbon deposits, etc.) on the inner and outer surfaces of the reactor, releasing the activity of the reactor.

[0105] In the present invention, the service life of the reactor is preferably more than 26000 h. The deactivated reactor can be recycled 100% without polluting the environment, belonging to an environment-friendly product.

[0106] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0107] Example 1

[0108] The non-aqueous raw materials are weighed according to the following mass percentages: fly ash 40%, ganzi clay 10%, bentonite 5%, precursor copper oxide 15%, pore-forming agent flour 10%, binder carboxymethyl cellulose 10%, adsorbent NiO 10%.

[0109] The main active acid-soluble metal salts include copper nitrate and ferrous nitrate. The molar ratio of copper element in copper nitrate to iron element in ferrous nitrate is 3:2. The co-active acid-soluble metal salts include cerium nitrate and nickel nitrate. The mass ratio of cerium nitrate to nickel nitrate is 1:1. The mass ratio of the main active acid-soluble metal salts to the co-active acid-soluble metal salts is 3:2.

[0110] In this example, the mass percentage of SiO2 in the fly ash is 50%, the mass percentage of Al2O3 is 30%, the mass percentage of MgO is 2%, the mass percentage of GaO is 1%, the mass percentage of K2O is 3%, the mass percentage of Na2O is 3%, the mass percentage of Fe2O3 is 5%. The particle diameter of the fly ash is 100 nm, the specific surface area is 500 m 2 / g, and the porosity is 50%.

[0111] Figure 6Schematic structural diagram of the device for preparing the reactor in Example 1, including: dryer 10, ultrafine grinder 12, mixer 11, clay kneader 4, granulator 5, sintering furnace 6, air cooler 7, reaction kettle 8 and dryer 9. The mixer 11 is connected to the clay kneader 4, the clay kneader 4 is connected to the granulator 5, the granulator 5 is connected to the dryer 10, the dryer 10 is connected to the sintering furnace 6, the sintering furnace 6 is connected to the reaction kettle 8, the reaction kettle 8 is connected to the dryer 9, the air cooler 7 is connected to the sintering furnace 6, the ultrafine grinder 12 is connected to the mixer 11. The mixer is a twin-screw mixer, the clay kneader is a special clay kneader for ceramic production, the granulator is an extruder, and the sintering furnace is an electric high-temperature muffle furnace.

[0112] The preparation method includes the following steps:

[0113] The components that are insoluble in water and have a small content (main active acid-soluble metal salt, co-active acid-soluble metal salt and adsorbent) are dried and calcined at 300 °C for 5 h in an electric furnace, and then crushed to 1000 meshes for substitution. The crushed adsorbent, fly ash, chamotte, bentonite, precursor, pore-forming agent and binder are mixed by the action of water medium in the mixer for 4 h to obtain a sealed material, which is left to ferment for 48 h, and then formed into spherical embryos with a diameter of 25 - 27 mm in the granulator. After natural air drying at 30 °C for 48 h, the dried embryos are placed in a muffle furnace and calcined at 850 °C for 20 h to obtain the matrix material;

[0114] The matrix material is soaked in a nitric acid solution according to an equal volume ratio. The mass concentration of the nitric acid solution is 30%, soaked at 30 °C for 6 h, and then dried at 200 °C for 3 h to obtain the carrier material;

[0115] Copper nitrate, ferrous nitrate, nickel nitrate, cerium nitrate and water are mixed to obtain an acidic metal salt solution. The mass concentration of the acidic metal salt solution is 30%. After soaking at 20 °C for 6 h in an equal volume, then dried at 100 °C for 10 h, and then calcined at 300 °C for 8 h to obtain the reactor for low-temperature catalytic decomposition of SO2.

[0116] Figure 1 Schematic structural diagram of the reactor prepared in Example 1 Figure 2 Physical diagram of the reactor prepared in Example 1 Figure 3 Schematic cross-sectional view of the pores of the reactor prepared in Example 1 Figure 4 Physical cross-sectional diagram of the pores of the reactor prepared in Example 1. It can be seen that the prepared reactor is a spherical reactor with a diameter of 26 mm, and macropores are distributed on the surface and inside. The macropores are loaded with a catalyst with dual active centers to form a mesoporous micro-reaction unit.

[0117] The reactor prepared in this embodiment has a binary spherical structure of macropores and mesopores, with a specific surface area of 1.00 - 2.00 m 2 / g, the number of macropores is 1.00×10 11 - 2.00×10 11 pieces, the diameter of macropores is 1000 - 2000 nm, the number of mesopores is 3.00×10 5 - 4.0×10 5 pieces, the diameter of mesopores is 20 - 30 nm, and the number of active sites of the main active metal oxide in each mesopore is 4.00×10 4 - 5.0×10 4 pieces.

[0118] The reactor prepared in this embodiment is used for low-temperature catalytic decomposition of SO2. The low-temperature catalytic decomposition of SO2 is carried out in a low-temperature desulfurization reaction tower. Figure 7 Figure 1 is a schematic external view of the low-temperature desulfurization reaction tower provided in Example 1. Figure 8 Figure 2 is a schematic structural view of the low-temperature desulfurization reaction tower provided in Example 1. The low-temperature desulfurization reaction tower includes a desulfurization tower 13, and a flue gas inlet pipe 14 and a flue gas outlet pipe 15 connected to both ends of the desulfurization tower 13. A reactor bed layer is provided in the desulfurization tower 13. A plurality of spherical reactors prepared in this embodiment are closely stacked in the reaction tower to form a reactor bed layer. Figure 5 Figure 3 is a partial schematic view of the reactor bed layer formed by stacking reactors in the reaction tower. The low-temperature catalytic decomposition of SO2 is carried out using the reactor bed layer placed in the desulfurization tower 13. The gas to be treated can enter through the flue gas inlet pipe 14, and is better catalytically decomposed by the reactor and discharged through the flue gas outlet pipe 15. The low-temperature desulfurization reaction tower further includes a draft fan 16, a chimney direct discharge bypass pipe 17 and a cut-off valve. The draft fan 16 is connected to the flue gas outlet pipe 15. One end of the chimney direct discharge bypass pipe 17 is connected to the flue gas outlet pipe 15, and the other end of the chimney direct discharge bypass pipe 17 is connected to the flue gas inlet pipe 14. The cut-off valve is provided on the flue gas inlet pipe 14, the flue gas outlet pipe 15 and the chimney direct discharge bypass pipe 17. The flue gas outlet pipe 15 is connected to the chimney. The multi-layer void volume of the reactor bed layer is 65%.

[0119] A certain waste flue gas (SO2 concentration 100 mg / m 2 , flue gas volume 180000 m 3 / h) is introduced into the low-temperature desulfurization reaction tower, and the temperature is raised to make the reactor (90 m 3) and the temperature inside the low-temperature desulfurization reaction tower rises to 100 °C. The flue gas flows into the tower body through the inlet flue pipe 14 under the action of the induced draft fan and enters the reactor. In the reactor, the SO2 in the waste flue gas is catalytically decomposed to generate S and O2. O2 is discharged through the outlet flue pipe 15 under the action of the induced draft fan, while the S element diffuses into the air with the flue gas discharge, aggregates into 8S aggregates after cooling, the removal rate of SO2 is 95%, and after continuous use for 50,000 h, the removal rate of SO2 is 93%.

[0120] The reactor after being used for 50,000 h is ground and then used again. Under the same conditions as in this example, the removal rate of SO2 is 93%.

[0121] Example 2

[0122] Same as Example 1, the only difference is that the molar ratio of copper element to iron element in the main active acid-soluble metal salt is 7:3.

[0123] The reactor prepared in this example has a macroporous and mesoporous binary spherical structure, with a specific surface area of 1.00 - 2.00 m 2 / g, the number of macropores is 1.00×10 11 - 2.00×10 11 pieces, the diameter of the macropores is 1000 - 2000 nm, the number of mesopores is 3.00×10 5 - 4.0×10 5 pieces, the diameter of the mesopores is 20 - 30 nm, and the number of the main active metal oxides loaded in each mesopore is 4.00×10 4 - 5.0×10 4 pieces.

[0124] The multi-layer void volume of the reactor bed in the low-temperature desulfurization reaction tower is more than 60%.

[0125] A certain waste flue gas (SO2 concentration 200 mg / m 2 , flue gas volume 180,000 m 3 / h) is introduced into the low-temperature desulfurization reaction tower, the temperature is raised to make the reactor (90 m 3 ) and the temperature inside the low-temperature desulfurization reaction tower rise to 100 °C. The flue gas flows into the tower body through the inlet flue pipe 14 under the action of the induced draft fan and enters the reactor. In the reactor, the SO2 in the waste flue gas is catalytically decomposed to generate S and O2. O2 is discharged through the outlet flue pipe 15 under the action of the induced draft fan, while the S element diffuses into the air with the flue gas discharge, aggregates into 8S aggregates after cooling, and the removal rate of SO2 is 85%.

[0126] Example 3

[0127] Same as Example 1, except that the molar ratio of copper element to iron element in the main active acid-soluble metal salt is 1:1.

[0128] The reactor prepared in this example has a binary spherical structure of macropores and mesopores, with a specific surface area of 1.00 - 2.00 m 2 / g, the number of macropores is 1.00×10 11 - 2.00×10 11 pieces, the diameter of macropores is 1000 - 2000 nm, the number of mesopores is 3.00×10 5 - 4.0×10 5 pieces, the diameter of mesopores is 20 - 30 nm, and the number of main active metal oxides loaded in each mesopore is 4.00×10 4 - 5.0×10 4 pieces.

[0129] The multi-layer void volume of the reactor bed in the low-temperature desulfurization reaction tower is more than 60%.

[0130] A certain waste flue gas (SO2 concentration 300 mg / m 2 , flue gas volume 180000 m 3 / h) is introduced into the low-temperature desulfurization reaction tower, and the temperature is raised to make the temperature in the reactor (90 m 3 ) and the low-temperature desulfurization reaction tower rise to 100 °C. The flue gas flows into the tower body through the inlet flue gas pipe 14 under the action of the induced draft fan and enters the reactor. In the reactor, the SO2 in the waste flue gas is catalytically decomposed to generate S and O2. The O2 is discharged through the outlet flue gas pipe 15 under the action of the induced draft fan, while the S element is discharged and diffused into the air with the flue gas, and aggregates into 8S aggregates after cooling. The removal rate of SO2 is 78%.

[0131] Example 4

[0132] Same as Example 1, except that:

[0133] A certain waste flue gas (SO2 concentration 100 mg / m 2 , flue gas volume 180000 m 3 / h) is introduced into the low-temperature desulfurization reaction tower, and the temperature is raised to make the temperature in the reactor (90 m 3 ) and the low-temperature desulfurization reaction tower rise to 130 °C. The flue gas flows into the tower body through the inlet flue gas pipe 14 under the action of the induced draft fan and enters the reactor. In the reactor, the SO2 in the waste flue gas is catalytically decomposed to generate S and O2. The O2 is discharged through the outlet flue gas pipe 15 under the action of the induced draft fan, while the S element is discharged and diffused into the air with the flue gas, and aggregates into 8S aggregates after cooling. The removal rate of SO2 is 98%.

[0134] Comparative Example 1

[0135] Same as Example 1, except that the fly ash in the matrix raw material is increased to 50%, and no grog is added.

[0136] The reactor prepared in this comparative example has a binary spherical structure of macropores and mesopores, and the specific surface area is 0.50 - 0.90 m 2 / g, the number of macropores is 5.00×10 8 -1.00×10 9 pcs, the diameter of macropores is 500 - 1000 nm, the number of mesopores is 3.00×10 3 -4.0×10 4 pcs, the diameter of mesopores is 20 - 30 nm, and the number of active sites of the main active metal oxide in the mesopores is 4.00×10 3 -5.0×10 3 pcs.

[0137] The waste flue gas (SO2 concentration 100 mg / m 2 , flue gas volume 180,000 m 3 / h) is introduced into the low-temperature desulfurization reaction tower, and the temperature is raised to increase the temperature in the reactor and the low-temperature desulfurization reaction tower to 100 °C. The flue gas flows into the tower body through the inlet flue pipe 14 under the action of the induced draft fan and enters the reactor. In the reactor, the SO2 in the waste flue gas is catalytically decomposed to generate S and O2. The O2 is discharged through the outlet flue pipe 15 under the action of the induced draft fan, while the S elemental substance diffuses into the air with the flue gas emissions and aggregates into 8S aggregates after cooling. The removal rate of SO2 is 60%.

[0138] Comparative Example 2

[0139] Same as Example 1, except that the calcination temperature of the matrix material is 1000 °C.

[0140] The reactor prepared in this comparative example has a binary spherical structure of macropores and mesopores, and the specific surface area is 0.40 - 0.60 m 2 / g, the number of macropores is 5.00×10 7 -1.00×10 8 pcs, the diameter of macropores is 200 - 500 nm, the number of mesopores is 3.00×10 2 -4.0×10 3 pcs, the diameter of mesopores is 10 - 15 nm, and the number of active sites of the main active metal oxide in the mesopores is 4.00×10 2 -5.0×10 2 pcs.

[0141] The waste flue gas (SO2 concentration 100 mg / m 2 , flue gas volume 180,000 m 3 / h) is introduced into the low-temperature desulfurization reaction tower, and the temperature of the reactor is raised to 100°C. The flue gas flows into the tower body through the smoke inlet pipe 14 under the power of the induced draft fan and enters the reactor. In the reactor, SO2 in the waste flue gas is catalytically decomposed to generate S and O2. O2 is discharged through the smoke outlet pipe 15 under the action of the induced draft fan, while the S single substance is diffused into the air with the flue gas discharge, and aggregates into 8S aggregates after cooling. The SO2 removal rate is 40%.

[0142] Comparative Example 3

[0143] According to the description of Example 3 of CN109647176A, a non-spherical activated ceramic dry process high-efficiency desulfurizer was prepared.

[0144] The prepared non-spherical activated ceramic dry-process high-efficiency desulfurizer Example 1 was used for catalytic decomposition of SO2 in a low-temperature desulfurization reaction tower. The temperature of the low-temperature desulfurization reaction tower was 100°C, and no S and O2 were generated.

[0145] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a reactor for catalytically decomposing SO2 at low temperature, characterized in that, It includes the following steps: Mix fly ash, ganzi soil, bentonite, precursor, pore former, binder, adsorbent and water, and then carry out kneading, mud waking fermentation, granulation and calcination in sequence to obtain a matrix material; Acid-leach the matrix material to obtain a carrier material; Impregnate the carrier material with an acidic metal salt solution, and then carry out drying and calcination in sequence to obtain the reactor. The solute of the acidic metal salt solution includes a main active acidic soluble metal salt and a co-active acidic soluble metal salt. The metal elements in the main active acidic soluble metal salt include copper and iron.

2. The preparation method according to claim 1, wherein Based on 100% of the non-aqueous raw materials, the matrix material is prepared from non-aqueous raw materials including the following mass percentages: fly ash 40-50%, ganzi soil 5-10%, bentonite 5-10%, precursor 15-20%, pore former 10-15%, binder 10-15% and adsorbent 5-10%.

3. The preparation method according to claim 1 or 2, characterized in that, The molar ratio of copper element to iron element in the main active acidic soluble metal salt is 3-7:2-5.

4. The preparation method according to claim 1, characterized in that, The granulation obtains spherical embryos, and the diameter of the spherical embryos is 20-40 mm.

5. The preparation method according to claim 1, characterized in that, The temperature of the calcination is 800-980 °C, and the time is 5-20 h.

6. The preparation method according to claim 1, characterized in that The temperature of the calcination is 300-500 °C, and the time is 5-8 h.

7. A reactor for low-temperature catalytic decomposition of SO2 prepared by the preparation method according to any one of claims 1-6.

8. The reactor according to claim 7, characterized in that, The reactor has a binary structure of macropores and mesopores, and the reactor is spherical with a diameter of 20-40 mm and a specific surface area of 1.00-2.00 m 2 / g.

9. The reactor according to claim 7 or 8, characterized in that, The number of macropores in the reactor is 1.00 × 10 11 ~2.00 × 10 11 pieces, the diameter of the macropores is 1000 - 2000 nm, the number of mesopores is 3.00 × 10 5 ~4.0 × 10 5 pieces, the diameter of the mesopores is 20 - 30 nm, the main active metal oxide is loaded in the mesopores, and the number of active sites of the main active metal oxide loaded on the surface of each mesopore is 4.00 × 10 4 ~5.0 × 10 4 pieces, and the main active metal oxide includes copper oxide and iron oxide.

10. Use of the reactor according to any one of claims 7 to 9 in the low-temperature catalytic decomposition of SO2, characterized in that, The temperature for low-temperature catalytic decomposition of SO2 is 100-130 °C.

Images