Catalyst for decomposing garbage odor, preparation method and application thereof, and garbage truck odor multi-stage treatment method

Abstract

The invention provides a catalyst for decomposing garbage odor, a preparation method and application thereof and a garbage truck odor multi-stage treatment method, and relates to the technical field of environmental protection, the catalyst takes TiO2-Al2O3 composite oxide as a carrier, and the carrier is loaded with an active component; and the active components comprise MnO2, CeO2 and Co3O4. The catalyst for decomposing garbage odor provided by the invention has high sulfur capacity and toxicity resistance, and has strong mechanical stability. Diesel engine tail gas waste heat is used as primary treatment energy, waste heat recycling is achieved, and energy consumption of a traditional treatment method is reduced; and through a multi-stage reaction chain of'pyrolysis-ionization-adsorption ', multiple modes are coupled, odor in the transportation process of the garbage truck is treated, the environment-friendly effect is achieved, and meanwhile the efficiency is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental protection, and in particular to a catalyst for decomposing garbage odor, a preparation method and application thereof, and a multi-stage garbage truck odor treatment method. BACKGROUND

[0002] In the garbage disposal process, it is usually necessary to transport the garbage to a disposal point for centralized treatment, and during transportation, odor harmful to the environment is inevitably generated. Although airtight methods are usually used, the harm of odor to the environment has not been fundamentally reduced. The existing garbage truck deodorization methods have the following defects: the traditional physical covering method cannot eliminate volatile organic compounds (VOCs), the chemical spraying method consumes a large amount of chemicals and has the risk of secondary pollution, and the biological deodorization method has a slow response speed and is difficult to adapt to a dynamic transportation environment.

[0003] At present, catalyst technology is gradually applied to the field of malodorous gas treatment, but still faces the following challenges: the existing catalysts have low conversion efficiency for specific odor components (such as hydrogen sulfide), and are prone to deactivation after a long time of operation, and have insufficient stability.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] One of the purposes of the present application is to provide a catalyst for decomposing garbage odor to at least solve one of the technical problems existing in the prior art. The catalyst for decomposing garbage odor provided by the present application has high sulfur capacity and anti-poisoning property, and has strong mechanical stability.

[0006] The second purpose of the present application is to provide a preparation method of a catalyst for decomposing garbage odor.

[0007] The third purpose of the present application is to provide a catalyst for decomposing garbage odor or a catalyst for decomposing garbage odor prepared by the preparation method in the treatment of garbage truck odor.

[0008] The fourth purpose of the present application is to provide a multi-stage garbage truck odor treatment method. The present application utilizes diesel engine exhaust heat as a primary treatment energy source, realizes the reuse of waste heat, and reduces the energy consumption of traditional treatment methods. Through a multi-stage reaction chain of "pyrolysis-ionization-adsorption", multiple ways are coupled to treat the odor in the garbage truck transportation process, achieve environmental protection effect, and greatly improve the efficiency.

[0009] In order to achieve the above purposes of the present application, the following technical solutions are adopted:

[0010] The first aspect of the present application provides a catalyst for decomposing garbage odor, wherein the catalyst is supported on a TiO2-Al2O3 composite oxide carrier, and the carrier is loaded with an active component.

[0011] The active component comprises MnO2, CeO2 and Co3O4.

[0012] Further, the loading amount of the active component is 20%-25%;

[0013] And / or, in the active component, the molar ratio of MnO2, CeO2 and Co3O4 is 4-6:2-4:1-3;

[0014] And / or, in the TiO2-Al2O3 composite oxide, the mass ratio of TiO2 to Al2O3 is 6-8:2-4;

[0015] And / or, the specific surface area of the TiO2-Al2O3 composite oxide is greater than or equal to 200 m 2 / g;

[0016] And / or, the carrier is further loaded with an auxiliary agent, which is finally present in the catalyst in the form of WO3 and / or La2O3 and functions.

[0017] The second aspect of the present application provides a preparation method of a catalyst for decomposing garbage odor, comprising the following steps: dipping a carrier in a mixed solution of Mn salt solution, Ce salt solution and Co salt solution, and then sequentially performing a first calcination and reduction treatment to obtain the catalyst.

[0018] Further, the TiO2-Al2O3 composite oxide carrier is prepared by the following method:

[0019] Titanium isopropoxide, aluminum isopropoxide and a solvent are mixed to form a mixed solution, nitric acid is added to the mixed solution to perform a hydrolysis reaction, and then aging and a first drying are sequentially performed to obtain the TiO2-Al2O3 composite oxide;

[0020] And / or, the molar ratio of titanium isopropoxide to aluminum isopropoxide is 19-51:20;

[0021] And / or, the temperature of the hydrolysis reaction is 38-42℃;

[0022] And / or, the temperature of the first drying is 115-125℃; and the time of the first drying is 10-14 hours.

[0023] Further, in the mixed solution of the Mn salt solution, the Ce salt solution and the Co salt solution, the concentration of the Mn salt solution is 0.4-0.6 mol / L, the concentration of the Ce salt solution is 0.2-0.4 mol / L, and the concentration of the Co salt solution is 0.3-0.9 mol / L;

[0024] And / or, the Mn salt solution comprises Mn(NO3)2·4H2O; the Ce salt solution comprises Ce(NO3)3·6H2O; and the Co salt solution comprises Co(NO3)2·6H2O;

[0025] And / or, the liquid-solid ratio of the mixed solution to the carrier is 4-6 mL:1 g;

[0026] And / or, the pH of the mixed solution impregnated with the carrier is 9.2-9.8;

[0027] And / or, the impregnated carrier is dried; the drying temperature is 105-115℃; and the drying time is 7-9 hours;

[0028] And / or, the first calcination comprises a programmed temperature calcination; the programmed temperature calcination comprises a first temperature rising section and a second temperature rising section; the temperature rising rate of the second temperature rising section is greater than that of the first temperature rising section; and the final temperature after the first calcination is 550±10℃;

[0029] And / or, the reduction treatment is carried out under a hydrogen and nitrogen atmosphere; the temperature of the reduction treatment is 390-410℃; and the time of the reduction treatment is 2-4 hours;

[0030] And / or, the preparation process of the catalyst further comprises: after the reduction treatment, a promoter modification; the promoter modification comprises: impregnating the carrier after the reduction treatment in a promoter raw material solution, and then carrying out a second calcination;

[0031] And / or, the promoter raw material solution comprises an ammonium tungstate solution and / or a lanthanum nitrate solution; and the concentration of the promoter raw material solution is 0.08-0.12 mol / L;

[0032] And / or, the temperature of the second calcination is 430-470℃; and the time of the second calcination is 1-3 hours.

[0033] In a third aspect, the present application provides a catalyst for decomposing garbage odor or a catalyst for decomposing garbage odor prepared by the preparation method.

[0034] In a fourth aspect, the present application provides a multi-stage garbage truck odor treatment method, comprising:

[0035] (a) primary treatment: the tail gas of the garbage truck is mixed with the garbage odor, and then the catalyst for decomposing garbage odor or the catalyst for decomposing garbage odor prepared by the preparation method is used for catalytic reaction;

[0036] (b) secondary treatment: applying voltage to the garbage odor treated in step (a);

[0037] (c) tertiary treatment: chemical adsorption of the garbage odor treated in step (b).

[0038] Further, the temperature of the primary treatment is 280-350℃; the temperature of the secondary treatment is 150-200℃; and the temperature of the tertiary treatment is normal temperature;

[0039] And / or, the process of chemical adsorption includes: sequentially performing reagent treatment and adsorption treatment on the garbage odor treated in step (b);

[0040] And / or, the composition of the reagent used in the reagent treatment includes: epsilon-polylysine hydrochloride, ferric ammonium citrate, nano ZnO quantum dots and hydroxypropyl-beta-cyclodextrin;

[0041] And / or, the filter core used in the adsorption treatment includes: activated carbon fiber felt loaded with Fe-MOFs.

[0042] Further, the multi-stage treatment method of the garbage truck odor uses a multi-stage treatment system to treat the garbage truck odor;

[0043] The multi-stage treatment system includes a waste heat recovery and thermal oxidation module, a plasma-catalysis synergistic module and a chemical adsorption module which are sequentially connected;

[0044] The waste heat recovery and thermal oxidation module includes a tail gas collection subsystem and a catalytic oxidation reactor; the tail gas collection subsystem is in communication with the catalytic oxidation reactor, and the tail gas collection subsystem is used to collect tail gas;

[0045] The plasma-catalysis synergistic module includes a dielectric barrier discharge reactor;

[0046] The chemical adsorption module includes a nano-atomization system and an adsorption filter core.

[0047] Further, the tail gas collection subsystem includes a coaxial double sleeve; the coaxial double sleeve includes an inner tube and an outer tube; the inner tube is arranged as an engine exhaust pipe; and the outer tube is arranged as an odor passage;

[0048] The electrode structure of the dielectric barrier discharge reactor is arranged as a zigzag stainless steel electrode, and the dielectric layer is arranged as an alumina ceramic; and the dielectric layer is provided with a Pt-Pd / Al2O3 catalyst;

[0049] The plasma-catalysis synergistic module further comprises an ozone co-production unit, the ozone co-production unit shares the same pair of electrodes with the dielectric barrier discharge reactor, and the two are coaxially nested and arranged in different zones, and pure oxygen is converted into ozone in the ozone co-production zone.

[0050] The nano-atomization system comprises an atomizer arranged as a piezoelectric ceramic high-frequency atomizer.

[0051] Compared with the prior art, the application has the following beneficial effects:

[0052] The catalyst for decomposing garbage odor provided by the application takes TiO2-Al2O3 composite oxide as a carrier, TiO2 and Al2O3 form an interpenetrating network structure, the pore size distribution is optimized, the mass transfer efficiency is enhanced, meanwhile, the surface hydroxyl density of the composite carrier is reduced, the collapse of the pore channel caused by high-temperature dehydration is reduced, therefore, the TiO2-Al2O3 composite oxide has strong thermal stability, and the composite carrier can enhance the adsorption and activation capacity of sulfur / nitrogen-containing pollutants (H2S, NH3), and has better catalytic performance; the application takes MnO2, CeO2 and Co3O4 as active components, MnO2 has strong oxidation capacity, can also synergize with TiO2 to further promote the light-generated carrier separation efficiency, reduce the electron-hole recombination probability, and improve the overall catalytic efficiency, CeO2 is an excellent oxygen storage material, can release oxygen in a reducing atmosphere and absorb oxygen in an oxidizing atmosphere, this feature enables CeO2 to effectively adjust the local oxygen concentration in the waste gas treatment process, which is conducive to improving the conversion rate of the reaction steps, meanwhile, CeO2 also shows good sulfur poisoning resistance, Co3O4 has excellent low-temperature oxidation activity, and when coexisting with other metal oxides, Co3O4 can also optimize the catalytic performance by forming a solid solution or interface effect. Therefore, the catalyst for decomposing garbage odor provided by the application not only enhances the decomposition capacity of garbage odor, but also improves the stability and poisoning resistance in long-term operation. DETAILED DESCRIPTION

[0053] Unless otherwise defined, scientific and technical terms used in connection with the application herein shall have the meanings that are commonly understood by those of ordinary skill in the art. Clear dictates that the meaning and scope of the terms should be clear; however, in the case of potential ambiguities, the definitions provided herein prevail over any dictionary or extrinsic definition. In this application, unless indicated otherwise, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0054] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0055] The first aspect of the present invention provides a catalyst for decomposing garbage odor, wherein the catalyst uses TiO2-Al2O3 composite oxide as a support, and the support is loaded with active components;

[0056] The active components include MnO2, CeO2 and Co3O4.

[0057] In some preferred embodiments, the loading of the active component is 20%-25%, for example, it can be 20%, 21%, 22%, 23%, 24%, 25%, etc.; the loading of the active component is preferably 21%-24%, more preferably 22%.

[0058] And / or, in the active components, the molar ratio of MnO2, CeO2 and Co3O4 is 4-6:2-4:1-3; "4-6" can be, for example, 4, 5, 6, etc.; "2-4" can be, for example, 2, 3, 4, etc.; "1-3" can be, for example, 1, 2, 3, etc.

[0059] And / or, in the TiO2-Al2O3 composite oxide, the mass ratio of TiO2 to Al2O3 is 6-8:2-4; "6-8" can be, for example, 6, 7, 8, etc.; "2-4" can be, for example, 2, 3, 4, etc.

[0060] And / or, the specific surface area of ​​the TiO2-Al2O3 composite oxide is ≥200m². 2 / g.

[0061] The catalyst for decomposing garbage odor provided by this invention is a Mn-Ce-Co / TiO2-Al2O3 composite support, and the catalyst has a specific surface area of ​​210±15 m². 2 / g, when using a catalyst to catalyze the reaction of garbage odor, the reaction conditions are a temperature of 280-350℃ and a space velocity of 4800-5200 h⁻¹. -1 H2S conversion rate is high.

[0062] In this invention, the active components of the catalyst are MnO2, CeO2 and Co3O4, with a preferred molar ratio of 5:3:2, and the support is a TiO2-Al2O3 composite oxide (the preferred mass ratio of TiO2 to Al2O3 is 7:3).

[0063] The TiO2-Al2O3 composite support used in this invention has the following advantages:

[0064] (1) Advantages of specific surface area and pore structure: The introduction of TiO2 inhibits Al2O3 sintering and maintains the high specific surface area phase of γ-Al2O3. TiO2 and Al2O3 form an interpenetrating network structure, optimize the pore size distribution, and enhance the mass transfer efficiency.

[0065] (2) Enhanced thermal stability: TiO2 forms a solid solution with Al2O3 (such as Al2TiO5), inhibiting Al2O3 lattice reconstruction. The hydroxyl density on the surface of the composite support is reduced, minimizing pore collapse caused by high-temperature dehydration.

[0066] (3) Superior catalytic performance. Enhanced adsorption and activation capacity for sulfur / nitrogen pollutants (H2S, NH3). The Lewis acid sites of TiO2 preferentially adsorb sulfur species, protecting active metals (such as Mn, Ce) from poisoning. The oxygen vacancies on the composite support (from TiO2) 3+ / Ti 4 + The formation of redox pairs promotes the oxidation of carbon deposits (C + O2 → CO2).

[0067] And / or, the support is also loaded with an auxiliary agent, which ultimately exists in the catalyst in the form of WO3 and / or La2O3 and functions therein.

[0068] In this invention, the active component MnO2 provides strong oxidizing properties (Mn 4+ / Mn 3+ (Circulation), activates H2S molecules, Mn 4+ +H2S→Mn 3+ +HS - +H + CeO2 oxygen storage release (CeO2 oxygen storage release) 4+ / Ce 3+ (Transformation); stable oxygen vacancies; the Co3O4 spinel structure provides stable oxygen channels, promoting deep oxidation: Co 3+ +O2→Co 2+ +O2· - →·OH.

[0069] WO3 additive, strong Lewis acid sites adsorb SO2, electron trap effect: W 6+ Electron trapping promotes Mn 4+ Regeneration (W) 6+ +e - →W 5 + La₂O₃ embedding into the Al₂O₃ lattice suppresses the phase transition (γ→α) and increases the oxygen vacancy concentration: La 3+ Al replacement 3+This induces lattice distortion. WO3 is dispersed on the support surface and forms WO-Mn electron bridges with the Mn-Ce-Co active components. The La2O3 additive is embedded in the Al2O3 lattice, forming a La-Al-O solid solution structure.

[0070] TiO2 support provides Lewis acid sites for NH3 adsorption, which then generates ·OH in response to UV light (photocatalytically assisted); Al2O3, Acid-protonated thiols (RSH→RSH2) + The high specific surface area stabilizes and disperses the active components; the two have a complex interface effect, with Ti-O-Al bonds enhancing electron transfer and interpenetrating networks resisting sintering.

[0071] And / or, the raw materials for preparing the auxiliary agent include ammonium tungstate and / or lanthanum nitrate.

[0072] In a second aspect, the present invention provides a method for preparing a catalyst for decomposing garbage odor.

[0073] The present invention provides a method for preparing a catalyst for decomposing garbage odor, comprising the following steps: impregnating a support in a mixed solution of Mn salt solution, Ce salt solution and Co salt solution, followed by sequential calcination and reduction treatment to obtain the catalyst.

[0074] In some preferred embodiments, in the mixed solution of Mn salt solution, Ce salt solution and Co salt solution, the concentration of the Mn salt solution is 0.4-0.6 mol / L, for example, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, etc.; the concentration of the Ce salt solution is 0.2-0.4 mol / L, for example, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, etc.; and the concentration of the Co salt solution is 0.3-0.9 mol / L, for example, 0.3 mol / L, 0.6 mol / L, 0.9 mol / L, etc.

[0075] And / or, the Mn salt solution comprises Mn(NO3)2·4H2O; the Ce salt solution comprises Ce(NO3)3·6H2O; the Co salt solution comprises Co(NO3)2·6H2O;

[0076] And / or, the liquid-to-solid ratio of the mixed solution to the carrier is 4-6 mL:1 g, where "4-6 mL" can be, for example, 4 mL, 5 mL, 6 mL, etc.

[0077] And / or, the pH of the mixed solution impregnated with the carrier is 9.2-9.8, for example, it can be 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, etc.; controlling the pH value of the precipitation is used to control the crystal form of the metal hydroxide.

[0078] And / or, the impregnated carrier is dried; the drying temperature is 105-115℃, for example, 105℃, 110℃, 115℃, etc.; the drying time is 7-9 hours, for example, 7 hours, 8 hours, 9 hours, etc.

[0079] And / or, the first calcination includes programmed temperature calcination; the programmed temperature calcination includes a first heating stage and a second heating stage; the heating rate of the second heating stage is greater than the heating rate of the first heating stage; wherein, in the first heating stage, the temperature rises from 100℃ to 350℃ (heating rate 2℃ / min, holding for 2 hours), and in the second heating stage, the temperature rises from 350℃ to 550℃ (heating rate 5℃ / min, holding for 4 hours).

[0080] And / or, the final temperature after one calcination is 550±10℃;

[0081] And / or, the reduction treatment is carried out in a hydrogen and nitrogen atmosphere; the temperature of the reduction treatment is 390-410°C, for example, 390°C, 400°C, 410°C, etc.; the time of the reduction treatment is 2-4 hours, for example, 2 hours, 3 hours, 4 hours, etc.

[0082] And / or, the preparation process of the catalyst further includes: after the reduction treatment, performing auxiliary agent modification; the auxiliary agent modification includes: impregnating the reduced support in an auxiliary agent raw material solution, followed by secondary calcination;

[0083] And / or, the auxiliary agent raw material solution includes ammonium tungstate solution and / or lanthanum nitrate solution; the concentration of the auxiliary agent raw material solution is 0.08-0.12 mol / L;

[0084] And / or, the temperature of the secondary calcination is 430-470℃, for example, 430℃, 450℃, 470℃, etc.; the time of the secondary calcination is 1-3h, for example, 1h, 2h, 3h, etc.

[0085] In this invention, the final temperature of the first calcination is controlled at 550±10℃ to prevent the Al2O3 phase transformation (γ→α); the reduction temperature is preferably 400℃ to generate MnO2-CeO2 solid solution; the concentration of ammonium tungstate is 0.08-0.12mol / L to optimize the distribution of acidic sites on the surface.

[0086] In some preferred embodiments, the TiO2-Al2O3 composite oxide support is prepared by the following method:

[0087] Nitric acid was added to a mixed solution of titanium isopropoxide (Ti(OCH(CH3)2)4), aluminum isopropoxide (Al(OCH(CH3)2)3) and solvent (preferably anhydrous ethanol) to carry out a hydrolysis reaction, followed by aging and drying to obtain the TiO2-Al2O3 composite oxide.

[0088] And / or, the molar ratio of titanium isopropoxide to aluminum isopropoxide is 19-51:20; "19-51" can be, for example, 19, 30, 51, etc.

[0089] And / or, the temperature of the hydrolysis reaction is 38-42℃, for example, it can be 38℃, 39℃, 40℃, 41℃, 42℃, etc.

[0090] And / or, the temperature of the first drying is 115-125℃; the drying time is 10-14 hours, for example, 10 hours, 12 hours, 14 hours, etc.

[0091] This invention significantly improves carrier performance and overcomes existing technological bottlenecks through the following innovative aspects:

[0092] (1) Process innovation to improve the precursor mixing mechanism.

[0093] Traditional methods often involve stepwise preparation of TiO2 and Al2O3 sols followed by mixing, resulting in uneven component dispersion. This invention employs a binary metal mixed precursor, forming a Ti-O-Al bond network through co-hydrolysis, enhancing component interactions. Secondly, hydrolysis is strictly controlled by introducing nitric acid-catalyzed hydrolysis (pH=3) to slow the alkoxide hydrolysis rate, preventing localized precipitation and achieving molecular-level uniform mixing. The specific surface area of ​​the carrier is increased. Furthermore, the carrier material of this invention exhibits superior performance, higher compressive strength, and better thermal stability. Through sol-gel self-generating pores forming an interpenetrating network structure, the pore wall thickness is uniform, resulting in stronger resistance to sintering.

[0094] (2) Innovative heat treatment improves the stability of the crystal phase.

[0095] This invention employs a gradient calcination process and a segmented heating strategy (100℃→350℃ slow dehydration→350℃→550℃ rapid crystallization) to suppress the transformation of γ-Al2O3 to the α-phase while maintaining the TiO2 anatase structure. Furthermore, a reducing atmosphere is maintained, and calcination is carried out in a N atmosphere containing 2% O2 to reduce oxygen vacancy defects, thereby increasing the specific surface area retention of the support at 650℃.

[0096] (3) Template-free design, balancing performance and cost.

[0097] Existing technologies require the addition of template agents to create pores, but this presents problems such as residual pollution and complex processes.

[0098] The core improvement of this invention lies in the replacement of template-based pore formation with spontaneous pore formation. By controlling the alkoxide concentration and hydrolysis rate, a wide mesoporous structure (8-12 nm) is formed, avoiding micropore clogging (template-based methods often have pore sizes <5 nm), thus improving mass transfer efficiency. It also offers environmental and economic advantages, eliminating the need for template addition and high-temperature removal steps, reducing energy consumption, and producing no CO2 / NOx emissions. Furthermore, the wide mesoporous structure obtained by this invention is more conducive to the diffusion and reaction of macromolecular pollutants (such as VOCs) during waste transportation, exhibiting high H2S oxidation conversion rate, excellent anti-carbon deposition performance, high sulfur capacity, and a moderate hydroxyl density on the carrier surface, preventing excessive surface adsorption that could lead to active site coverage.

[0099] The catalyst provided by this invention for decomposing garbage odor is a sulfur-poison-resistant Mn-Ce-Co ternary catalyst with high sulfur capacity and resistance to poisoning. Its sulfur capacity reaches 35% (compared to 20-25% for conventional catalysts), and after 200 hours of continuous operation, the H2S conversion rate remains >95% (compared to around 70% for conventional catalysts). This is because the oxygen storage function of CeO2 promotes the oxidation of sulfur species. (Circulation), while WO3 inhibits sulfate formation (through competitive adsorption).

[0100] Furthermore, this catalyst exhibits excellent low-temperature activity, with an ignition temperature (T50) as low as 180℃ (compared to ≥250℃ for conventional catalysts). This is because the synergistic effect of the Mn-Ce-Co ternary catalyst reduces the activation energy.

[0101] In addition, the catalyst has strong mechanical stability, the TiO2-Al2O3 composite support forms an interpenetrating network structure, and ammonium tungstate enhances the surface bonding force.

[0102] In a third aspect, the present invention provides a catalyst for decomposing garbage odor, or the application of a catalyst for decomposing garbage odor prepared by the aforementioned preparation method in the treatment of garbage truck odor.

[0103] Existing technologies often employ single-technology treatment, resulting in low efficiency. Furthermore, traditional physical covering and biological deodorization methods ultimately fail to achieve the harmless treatment of odorous gases during transportation. This invention innovatively utilizes the transport vehicle's own energy; the waste heat from the diesel engine exhaust can reach 400-600℃ during transport. This invention fully utilizes this heat energy to propose an effective method for treating odorous gases during transportation.

[0104] Therefore, in a fourth aspect, the present invention provides a multi-stage odor treatment method for garbage trucks, comprising:

[0105] (a) Primary treatment: After mixing the exhaust gas from the garbage truck with the garbage odor, a catalytic reaction is carried out using the catalyst for decomposing garbage odor as described above or the catalyst for decomposing garbage odor (Mn-Ce-Co / TiO2-Al2O3 composite support) prepared by the preparation method described above; the catalytic oxidation stage of the primary treatment greatly reduces the H2S concentration.

[0106] (b) Secondary treatment: Voltage is applied to the odorous waste gas after the treatment in step (a); the plasma stage of the secondary treatment improves the NH3 removal rate;

[0107] (c) Tertiary treatment: Chemical adsorption is performed on the odorous waste gas after step (b); the chemical adsorption stage in the tertiary stage further improves the removal rate of VOCs.

[0108] In some preferred embodiments, the temperature of the first-stage treatment is 280-350℃, for example, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, etc.; the temperature of the second-stage treatment is 150-200℃, for example, 150℃, 175℃, 200℃, etc.; and the temperature of the third-stage treatment is room temperature.

[0109] In the process of this invention, temperature control is achieved through a triple control of active heating, dynamic heat dissipation, and intelligent feedback. The active heating system includes a PTC ceramic heater, a waste heat recovery pipe for exhaust gas, and a temperature sensor array. The dynamic heat dissipation system includes a vortex air cooling channel, a semiconductor water cooling module, and a phase change material layer. Combined with the intelligent temperature control system, precise temperature control is achieved.

[0110] And / or, the chemical adsorption process includes: sequentially subjecting the waste odor gas treated in step (b) to reagent treatment and adsorption treatment;

[0111] And / or, the composition of the agent used in the treatment includes: ε-polylysine hydrochloride, ferric ammonium citrate, nano-ZnO quantum dots and hydroxypropyl-β-cyclodextrin;

[0112] In this invention, harmful gases are further removed at room temperature, and the agent is evenly dispersed for deodorization. The functions of each component in the agent are as follows:

[0113] ε-Polylysine hydrochloride: Adsorbs negatively charged odor molecules (such as H2S and thiols) through its cationic properties (carrying a +15mV charge at pH 5). It also disrupts microbial cell membranes, inhibiting the growth of putrefactive bacteria.

[0114] Ferric ammonium citrate: Fe3+ undergoes a redox reaction with sulfides: Fe 3+ +H₂S→FeS↓+2H + It chelates heavy metal ions to prevent catalyst poisoning.

[0115] Nano-ZnO quantum dots: photocatalytic degradation of VOCs (requires UV LED):

[0116] ZnO + hv → e - +h + h + +H2O→·OH; has antibacterial properties.

[0117] HP-β-CD: Encapsulates hydrophobic odor molecules (such as methanethiol) to form inclusion complexes, increasing their carrying capacity in droplets. It also maintains the dispersion stability of nano-ZnO through steric hindrance.

[0118] Preferably, the composition of the agent includes: 0.8 wt% ε-polylysine hydrochloride, 0.2 wt% ferric ammonium citrate, 0.5 wt% nano-ZnO quantum dots (particle size 4 nm), 1.5 wt% hydroxypropyl-β-cyclodextrin, and the balance being solvent.

[0119] The solvent is a water-ethanol-glycerol composite system, with 85-90 wt% deionized water (total solvent mass), 5-8 wt% anhydrous ethanol, and 2-3 wt% glycerol. The nano-ZnO quantum dots are coated with hydroxypropyl-β-cyclodextrin at a mass ratio of 1:2-1:3. Water is the primary solvent to ensure efficient dissolution of the hydrophilic components (ε-polylysine, ferric ammonium citrate); ethanol serves as a co-solvent to improve the dispersibility of the hydrophobic components and accelerate droplet drying; and glycerol acts as a humectant to maintain the long-term stability of the solution.

[0120] And / or, the filter element used in the adsorption treatment includes: activated carbon fiber felt loaded with Fe-MOFs.

[0121] The multi-stage odor treatment method for garbage trucks provided by this invention can achieve energy cascade utilization, specifically:

[0122] First stage (i.e., primary treatment, high-temperature section): Utilize the waste heat of the exhaust gas to heat the odorous gas from the ambient temperature to 300±20℃, with high thermal energy utilization rate; Reaction formula: CH3SH+3O2→CO2+2H2O+SO2 (ΔH=-890kJ / mol); 2H2S+3O2→2SO2+2H2O.

[0123] Second stage (i.e., secondary treatment, intermediate temperature range): Plasma triggers a chain reaction at 150-200℃:

[0124] e-+O2→O·+O·; O·+H2O→2·OH.

[0125] Level 3 (i.e., Level 3 treatment, ambient temperature stage): Targeted capture of residual pollutants using chemical agents: Zn 2+ +S 2-→ZnS↓.

[0126] Furthermore, unlike single plasma decomposition, this invention involves a multi-stage chain reaction of pyrolysis, ionization, and chemical adsorption to reduce odor pollution.

[0127] In some preferred embodiments, the multi-stage odor treatment method for garbage trucks employs a multi-stage treatment system to treat the odor from garbage trucks.

[0128] In detail regarding the multi-stage odor treatment system for garbage trucks:

[0129] The multi-stage treatment system includes a waste heat recovery and thermal oxidation module, a plasma-catalysis synergistic module, and a chemical adsorption module connected in sequence.

[0130] The following is a preferred implementation of a multi-stage odor treatment system for garbage trucks used in the multi-stage odor treatment process:

[0131] The primary treatment step employs a waste heat recovery and thermal oxidation module.

[0132] The waste heat recovery and thermal oxidation module includes an exhaust gas collection subsystem and a catalytic oxidation reactor. The exhaust gas collection subsystem is connected to the catalytic oxidation reactor and is used to collect exhaust gas. The exhaust gas collection subsystem has a coaxial double-pipe design. The inner pipe is the engine exhaust pipe, made of 310S stainless steel with a wall thickness of 3mm. The outer pipe is the odor channel, with a diameter ratio of 1:1.5. The heat exchange method adopts counter-vortex heat exchange, which has high thermal efficiency. The catalyst in the catalytic oxidation reactor is a Mn-Ce-Co / TiO2-Al2O3 composite support. The reaction conditions are a temperature of 280-350℃ and a space velocity of 4800-5200h⁻¹. -1 .

[0133] The secondary processing step utilizes a plasma-catalysis synergistic module.

[0134] The plasma-catalysis synergistic module includes a dielectric barrier discharge (DBD) reactor. The DBD reactor has a serrated stainless steel electrode structure (5mm pitch, 2mm depth), and a dielectric layer of 99% alumina ceramic (1.5mm thickness). A Pt-Pd / Al₂O₃ catalyst is coated (50-200μm thickness, preferably 125μm) onto the surface of the ceramic dielectric layer of the DBD reactor, i.e., the inner side of the alumina ceramic tube, directly contacting the plasma discharge region. The power supply parameters are bipolar nanosecond pulses (rise time 50ns, pulse width 200ns, frequency 10kHz, peak voltage 25kV), and the free radical yield is ·OH concentration ≥ 5×10⁻⁶. 16 mol / cm 3 Electron density 1.2 × 10⁻⁶15 cm -3 .

[0135] The role of the Pt-Pd / Al2O3 catalyst is as follows: the high-energy electrons (1-10 eV) generated by plasma discharge can directly excite the metal active sites (Pt-Pd) on the catalyst surface, inducing the generation of more oxygen vacancies and active oxygen species. The active substances generated by plasma (such as O3 and ·OH) undergo a chain reaction in the catalyst bed.

[0136] O3 + Pt → O2 + O·; O· + H2O → 2·OH; Ozone (O3) and free radicals generated by plasma are further reacted in the catalytic bed to achieve deep mineralization of pollutants.

[0137] Optionally, the plasma-catalysis synergistic module also includes an ozone co-production unit. The ozone co-production unit shares the same pair of electrodes with the dielectric barrier discharge reactor; the two are coaxially nested and partitioned, with pure oxygen converted into ozone in the ozone co-production zone. The discharge gap of the ozone co-production unit is 2 mm, the oxygen flow rate is 2 L / min, and the O3 production is ≥15 g / h. Ozone (O3) and free radicals generated by the plasma further react in the catalytic bed to reduce pollutants.

[0138] Specifically, the ozone co-production unit utilizes the same pair of electrodes (serrated high-voltage electrode + grounding electrode) from the DBD reactor, achieving functional separation through a zoned design. The two zones are isolated by gas paths: the main reaction zone of the DBD is irritated with odorous gas, while the ozone co-production zone is irritated with pure oxygen (or oxygen-enriched air), and the two zones are physically separated by ceramic partitions.

[0139] The process involves a three-stage treatment step using a chemical adsorption module.

[0140] The chemical adsorption module includes a nano-atomization system and an adsorption filter. The nano-atomization system uses a piezoelectric ceramic high-frequency atomizer (resonant frequency 1.7MHz, droplet D50 = 3.5μm). The reagent used in the nano-atomization system is the aforementioned reagent formulation with ε-polylysine hydrochloride as the main agent. The adsorption filter is an activated carbon fiber felt (10mm thick, iodine value 1100mg / g) loaded with Fe-MOFs (MIL-101(Fe)). This invention employs a novel material system, different from ordinary activated carbon adsorption, utilizing MOF-modified nanocomposite adsorbents to adsorb and remove odors.

[0141] Optionally, when the H2S concentration is detected to be >100ppm, the system activates the emergency mode, triggers the secondary plasma power supply (voltage rises to 28kV), and increases the reagent injection rate to 1.2L / h.

[0142] The garbage truck odor multi-stage treatment system provided by the present invention includes a three-stage treatment system consisting of a waste heat recovery and thermal oxidation module, a plasma-catalytic synergistic module, and a chemical adsorption module. The connection relationship is as follows: exhaust pipe → vortex mixing chamber → catalytic bed → DBD reactor → atomization chamber → adsorption filter.

[0143] The multi-stage odor treatment method for garbage trucks provided by this invention is a multi-stage odor treatment method for garbage trucks based on high-temperature flue gas synergistic plasma coupling. It combines a composite deodorization system of waste heat recovery from the exhaust gas of the garbage truck's diesel engine, plasma catalytic oxidation, and nanoscale chemical adsorption. It is suitable for the efficient removal of malodorous substances such as hydrogen sulfide (H2S), ammonia (NH3), and volatile organic compounds (VOCs) from garbage transport vehicles under mobile operating conditions, solving the problem of environmental pollution caused by garbage odor during transportation using traditional methods. At the same time, it can achieve high energy utilization, reduce external power supply, realize waste heat recovery, and cascade energy utilization, making it more energy-efficient.

[0144] Optionally, the present invention employs an intelligent control system to detect gases in the transport vehicle, including the following sensors:

[0145] H2S electrochemical sensor (range 0-100ppm, accuracy ±1%);

[0146] NH3 infrared sensor (range 0-200ppm, resolution 0.5ppm);

[0147] VOCs PID sensor (range 0-1000ppb, response time <2s).

[0148] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0149] It should be noted that the waste sources used in the following embodiments and comparative examples are the same batch of waste sources.

[0150] Example 1

[0151] This embodiment provides a catalyst for decomposing garbage odor, and the preparation process is as follows:

[0152] (1) Carrier synthesis (sol-gel method):

[0153] Titanium isopropoxide Ti(OCH(CH3)2)4 and aluminum isopropoxide Al(OCH(CH3)2)3 were dissolved in anhydrous ethanol at a molar ratio of 3:2 to form a 0.5 mol / L mixed solution.

[0154] Add nitric acid dropwise to adjust the pH to 3 and control the hydrolysis temperature at 40℃;

[0155] After aging for 24 hours, the product was dried at 120°C for 12 hours to obtain TiO2-Al2O3 composite gel.

[0156] (2) Loading of active components (coprecipitation method)

[0157] Preparation of metal salt solutions: Mn(NO3)2·4H2O (0.5mol / L), Ce(NO3)3·6H2O (0.3mol / L), Co(NO3)2·6H2O (0.6mol / L);

[0158] The carrier was immersed in the above solution at a liquid-to-solid ratio of 5:1 (mL / g); then NH4HCO3 solution (1mol / L) was added dropwise until pH = 9.5, and the stirring speed was 800 rpm; after aging for 6 hours, it was centrifuged and dried at 110℃ for 8 hours.

[0159] (3) Calcination and activation

[0160] First, perform programmed heating and calcination:

[0161] 100℃→350℃ (heating rate 2℃ / min, hold for 2 hours);

[0162] 350℃→550℃ (heating rate 5℃ / min, hold for 4 hours);

[0163] The process is then carried out with hydrogen reduction: H2 / N2 atmosphere (where H2 content is 5%, oxygen content is 2%, and the balance is N2), reduction at 400℃ for 3 hours.

[0164] (4) Modification of additives

[0165] Impregnation method for loading ammonium tungstate: The product prepared above is impregnated with 0.1 mol / L (NH4) solution. 10 W 12 O 41 Solution (immersion time 4 hours); followed by secondary calcination: calcination at 450℃ in air atmosphere for 2 hours.

[0166] The final catalyst was a Mn-Ce-Co / TiO2-Al2O3 composite support, in which the active components included MnO2, CeO2, and Co3O4 (in a molar ratio of 5:3:2). The mass ratio of TiO2 to Al2O3 in the TiO2-Al2O3 composite support was 7:3. The loading of the active components was measured to be 22 wt% by inductively coupled plasma atomic emission spectrometry, and the loading of WO3 was measured to be 1.15 wt% by X-ray fluorescence spectrometry.

[0167] Example 2

[0168] This embodiment provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that:

[0169] In step (1), the molar ratio of titanium isopropoxide Ti(OCH(CH3)2)4 to aluminum isopropoxide Al(OCH(CH3)2)3 is 19:20; the hydrolysis temperature is 38℃.

[0170] In step (2), prepare the metal salt solutions: Mn(NO3)2·4H2O (0.4mol / L), Ce(NO3)3·6H2O (0.4mol / L), Co(NO3)2·6H2O (0.3mol / L); add NH4HCO3 solution (1mol / L) dropwise until pH = 9.8;

[0171] In step (4), the product prepared above is impregnated with 0.08 mol / L (NH4) solution. 10 W 12 O 41 Solution;

[0172] The remaining steps are the same as in Example 1;

[0173] The final catalyst was a Mn-Ce-Co / TiO2-Al2O3 composite support, in which the active components included MnO2, CeO2, and Co3O4 (molar ratio of 4:4:1). The mass ratio of TiO2 to Al2O3 in the TiO2-Al2O3 composite support was 6:4 (i.e., 3:2). The loading of the active components was measured to be 20 wt% by inductively coupled plasma atomic emission spectrometry, and the loading of WO3 was measured to be 1.09 wt% by X-ray fluorescence spectrometry.

[0174] Example 3

[0175] This embodiment provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that:

[0176] In step (1), the molar ratio of titanium isopropoxide Ti(OCH(CH3)2)4 to aluminum isopropoxide Al(OCH(CH3)2)3 is 51:20; the hydrolysis temperature is 42℃.

[0177] In step (2), prepare the metal salt solutions: Mn(NO3)2·4H2O (0.6mol / L), Ce(NO3)3·6H2O (0.2mol / L), Co(NO3)2·6H2O (0.9mol / L); add NH4HCO3 solution (1mol / L) dropwise until pH = 9.2;

[0178] In step (4), the product prepared above is impregnated with 0.12 mol / L (NH4) solution. 10 W12 O 41 Solution;

[0179] The remaining steps are the same as in Example 1;

[0180] The final catalyst was a Mn-Ce-Co / TiO2-Al2O3 composite support, in which the active components included MnO2, CeO2, and Co3O4 (molar ratio of 6:2:3). The mass ratio of TiO2 to Al2O3 in the TiO2-Al2O3 composite support was 8:2 (i.e., 4:1). The loading of the active components was measured to be 25 wt% by inductively coupled plasma atomic emission spectrometry, and the loading of WO3 was measured to be 1.2 wt% by X-ray fluorescence spectrometry.

[0181] Example 4

[0182] This embodiment provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that:

[0183] In step (1), the molar ratio of titanium isopropoxide Ti(OCH(CH3)2)4 to aluminum isopropoxide Al(OCH(CH3)2)3 is 32:50;

[0184] In step (2), the following metal salt solutions are prepared: Mn(NO3)2·4H2O (0.3mol / L), Ce(NO3)3·6H2O (0.5mol / L), and Co(NO3)2·6H2O (0.3mol / L);

[0185] In step (4), the product prepared above is impregnated with 0.07 mol / L (NH4) solution. 10 W 12 O 41 Solution;

[0186] The remaining steps are the same as in Example 1;

[0187] The final catalyst was a Mn-Ce-Co / TiO2-Al2O3 composite support, in which the active components included MnO2, CeO2, and Co3O4 (molar ratio of 3:5:1). The mass ratio of TiO2 to Al2O3 in the TiO2-Al2O3 composite support was 5:5 (i.e., 1:1). The loading of the active components was measured to be 21 wt% by inductively coupled plasma atomic emission spectrometry, and the loading of WO3 was measured to be 1.09 wt% by X-ray fluorescence spectrometry.

[0188] Example 5

[0189] This embodiment provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that:

[0190] In step (1), the molar ratio of titanium isopropoxide Ti(OCH(CH3)2)4 to aluminum isopropoxide Al(OCH(CH3)2)3 is 23:4;

[0191] In step (2), the following metal salt solutions are prepared: Mn(NO3)2·4H2O (0.7mol / L), Ce(NO3)3·6H2O (0.1mol / L), and Co(NO3)2·6H2O (1.2mol / L);

[0192] In step (4), the product prepared above is impregnated with 0.13 mol / L (NH4) solution. 10 W 12 O 41 Solution;

[0193] The remaining steps are the same as in Example 1;

[0194] The final catalyst was a Mn-Ce-Co / TiO2-Al2O3 composite support, in which the active components included MnO2, CeO2, and Co3O4 (molar ratio of 7:1:4). The mass ratio of TiO2 to Al2O3 in the TiO2-Al2O3 composite support was 9:1. The loading of the active components was measured to be 24 wt% by inductively coupled plasma atomic emission spectrometry, and the loading of WO3 was measured to be 1.13 wt% by X-ray fluorescence spectrometry.

[0195] Example 6

[0196] This embodiment provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that:

[0197] In step (2), add NH4HCO3 solution (1 mol / L) dropwise until pH = 9;

[0198] In step (3), the temperature is increased by calcination: 100℃→250℃ (heating rate 2℃ / min, holding for 2 hours); 350℃→450℃ (heating rate 5℃ / min, holding for 4 hours);

[0199] The remaining steps are the same as in Example 1;

[0200] The final catalyst was a Mn-Ce-Co / TiO2-Al2O3 composite support, in which the active components included MnO2, CeO2, and Co3O4 (in a molar ratio of 5:3:1). The mass ratio of TiO2 to Al2O3 in the TiO2-Al2O3 composite support was 7:3. The loading of the active components was measured to be 21.5 wt% by inductively coupled plasma atomic emission spectrometry, and the loading of WO3 was measured to be 1.3 wt% by X-ray fluorescence spectrometry.

[0201] Example 7

[0202] This embodiment provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that:

[0203] In step (2), add NH4HCO3 solution (1 mol / L) dropwise until pH = 10;

[0204] In step (3), the temperature is increased by calcination: 100℃→400℃ (heating rate 2℃ / min, holding for 2 hours); 400℃→650℃ (heating rate 5℃ / min, holding for 4 hours);

[0205] The remaining steps are the same as in Example 1;

[0206] The final catalyst was a Mn-Ce-Co / TiO2-Al2O3 composite support, in which the active components included MnO2, CeO2, and Co3O4 (in a molar ratio of 10:1:4). The mass ratio of TiO2 to Al2O3 in the TiO2-Al2O3 composite support was 7:3. The loading of the active components was measured to be 20.3 wt% by inductively coupled plasma atomic emission spectrometry, and the loading of WO3 was measured to be 1.1 wt% by X-ray fluorescence spectrometry.

[0207] Example 8

[0208] This embodiment provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that: in step (3), programmed temperature rise calcination is not used, but constant temperature calcination is used directly. The calcination temperature is 550℃, and the calcination time is consistent with the treatment time in Example 1.

[0209] The remaining steps are the same as in Example 1;

[0210] The final catalyst was a Mn-Ce-Co / TiO2-Al2O3 composite support, in which the active components included MnO2, CeO2, and Co3O4 (in a molar ratio of 5:6:4). The mass ratio of TiO2 to Al2O3 in the TiO2-Al2O3 composite support was 7:3. The loading of the active components was measured to be 20.1 wt% by inductively coupled plasma atomic emission spectrometry, and the loading of WO3 was measured to be 1.12 wt% by X-ray fluorescence spectrometry.

[0211] Examples 9-16

[0212] Examples 9-16 provide a multi-stage odor treatment method for garbage trucks, all employing the multi-stage odor treatment system for garbage trucks described above (implementation method). Examples 9-16 respectively use the catalysts for decomposing garbage odors prepared in Examples 1-8. The multi-stage odor treatment method for garbage trucks includes the following steps:

[0213] (a) Primary treatment steps using a waste heat recovery and thermal oxidation module (which includes a tail gas collection subsystem and a catalytic oxidation reactor):

[0214] Start-up phase: When the engine speed reaches 1500 rpm and the exhaust gas temperature is >300℃, the waste heat recovery valve is automatically opened. The odor gas and exhaust gas are mixed at a volume ratio of 1:4 and enter the catalytic reactor for catalytic oxidation reaction (in Examples 9-16, the measured temperatures of the catalytic oxidation stage are 325℃, 320℃, 300℃, 280℃, 325℃, 330℃, 350℃, and 315℃, respectively, with a residence time of 0.8s). The catalysts in the catalytic reactors of Examples 9-16 are the catalysts prepared in Examples 1-8, respectively.

[0215] (b) A secondary treatment step is performed using a plasma-catalysis synergistic module (which includes a dielectric barrier discharge (DBD) reactor):

[0216] After treatment in step (a), the garbage odor enters the plasma-catalysis synergistic module, which applies a 20kV pulse voltage to the garbage odor.

[0217] (c) A three-stage treatment process is performed using a chemical adsorption module (which includes a nano-atomization system and an adsorption filter element):

[0218] After treatment in step (b), the garbage odor enters the chemical adsorption module. The reagent injection rate in the nano-atomization system is 0.5 L / h. Then, the adsorption filter cartridge adsorbs and filters the garbage odor.

[0219] The reagent consists of: 0.8 wt% ε-polylysine hydrochloride, 0.2 wt% ferric ammonium citrate, 0.5 wt% nano-ZnO quantum dots (4 nm particle size), 1.5 wt% hydroxypropyl-β-cyclodextrin, and the balance solvent. The solvent is a water-ethanol-glycerol composite system, with 90 wt% deionized water (accounting for 8 wt% of the total solvent mass), 8 wt% anhydrous ethanol, and 2 wt% glycerol. The nano-ZnO quantum dots are coated with hydroxypropyl-β-cyclodextrin at a mass ratio of 1:3. The preparation process is as follows: deionized water + HP-β-CD → ultrasonic dispersion → addition of nano-ZnO quantum dots → secondary ultrasonication → addition of ε-polylysine hydrochloride → addition of ferric ammonium citrate (adjusting pH = 5.2) → addition of ethanol / glycerol → three-stage filtration (1 μm filter membrane).

[0220] The adsorption filter element is an activated carbon fiber felt (10 mm thick, iodine value 1100 mg / g) loaded with Fe-MOFs (MIL-101(Fe)).

[0221] Example 17

[0222] This embodiment provides a multi-stage odor treatment method for garbage trucks, which differs from Embodiment 9 in that the reagent components used in step (c) do not contain nano-ZnO quantum dots.

[0223] Example 18

[0224] This embodiment provides a multi-stage odor treatment method for garbage trucks, which differs from Embodiment 9 in that the adsorption filter element is an activated carbon fiber felt (without loading other substances).

[0225] Comparative Example 1

[0226] This comparative example provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that Ti(OCH(CH3)2)4 is not added during the synthesis of the support in step (1), that is, the support of the final catalyst is only Al2O3; the remaining preparation steps are the same as those in Example 1.

[0227] Comparative Example 2

[0228] This comparative example provides a catalyst for decomposing garbage odor. The preparation process differs from that of Example 1 in that Al(OCH(CH3)2)3 is not added during the synthesis of the support in step (1), that is, the support of the final catalyst is only TiO2; the remaining preparation steps are the same as those in Example 1.

[0229] Comparative Example 3

[0230] This comparative example provides a catalyst for decomposing garbage odor. The difference from Example 1 is that in step (2), the metal salt solution does not contain Ce(NO3)3·6H2O, that is, the final catalyst does not contain CeO2; the remaining preparation steps are the same as in Example 1.

[0231] Comparative Example 4

[0232] This comparative example provides a catalyst for decomposing garbage odor. The difference from Example 1 is that in step (2), the metal salt solution does not contain Co(NO3)2·6H2O, that is, the final catalyst does not contain Co3O4; the remaining preparation steps are the same as in Example 1.

[0233] Comparative Examples 5-8

[0234] Comparative Examples 5-8 provide a multi-stage treatment method for garbage truck odor, which uses the catalysts prepared in Comparative Examples 1-4 for decomposing garbage odor. The treatment steps of the multi-stage treatment method for garbage truck odor provided in Comparative Examples 5-8 are the same as those in Example 9.

[0235] Comparative Example 9

[0236] This comparative example provides a multi-stage odor treatment method for garbage trucks, which differs from Example 9 in that step (b) secondary treatment is not performed.

[0237] Comparative Example 10

[0238] This comparative example provides a multi-stage odor treatment method for garbage trucks, which differs from Example 9 in that step (c) tertiary treatment is not performed.

[0239] Test case

[0240] Test samples: The gases treated in Examples 9-18 and Comparative Examples 5-10 were tested.

[0241] Test method:

[0242] H2S was detected using an H2S electrochemical sensor (range 0-100ppm, accuracy ±1%).

[0243] NH3 is detected using an NH3 infrared sensor (range 0-200ppm, resolution 0.5ppm);

[0244] VOCs are detected using a VOCs PID sensor (range 0-1000ppb, response time <2s).

[0245] The test conditions are as follows:

[0246] The initial concentration of HS was 200 ppm, and the treatment capacity was 10 m³ / min. 3 / h;

[0247] Regarding catalyst life testing: continuous operation for 1000 hours.

[0248] The test results are shown in Table 1.

[0249] Table 1

[0250]

[0251] As can be seen from the data in Table 1, through Example 9 and Comparative Examples 5-10, the catalyst prepared using the catalyst formulation provided by the present invention has better overall performance, significantly improves the odor treatment effect, reduces energy consumption, and extends the catalyst life.

[0252] As can be seen from Example 9 and Comparative Examples 9-10, the multi-stage synergistic treatment method of "pyrolysis-ionization-adsorption" of the present invention has a synergistic effect in odor purification, and the absence of any one stage will seriously affect the purification effect.

[0253] As can be seen from Examples 9 and 12-15, within the preferred raw material formulation range and the preferred process parameter range of the present invention, the catalyst has better overall performance, thereby achieving higher pollutant removal efficiency and longer service life.

[0254] As can be seen from Examples 9 and 16-18, if the catalyst preparation process does not employ a gradient heating calcination process, or if the reagent components or filter element provided by this invention are not used during the treatment process, the removal rates of H2S, NH3, and VOCs will decrease, energy consumption will increase, and catalyst lifespan will be shortened, thereby affecting the overall treatment effect.

[0255] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst for decomposing garbage odor, characterized in that, The catalyst uses TiO2-Al2O3 composite oxide as a support, and the support is loaded with active components. The active components include MnO2, CeO2 and Co3O4.

2. The catalyst for decomposing garbage odor according to claim 1, characterized in that, The loading of the active component is 20%-25%; And / or, in the active components, the molar ratio of MnO2, CeO2 and Co3O4 is 4-6:2-4:1-3; And / or, in the TiO2-Al2O3 composite oxide, the mass ratio of TiO2 to Al2O3 is 6-8:2-4; And / or, the specific surface area of ​​the TiO2-Al2O3 composite oxide is ≥200m². 2 / g; And / or, the support is also loaded with an additive, which exists in the form of WO3 and / or La2O3 in the catalyst.

3. The method for preparing the catalyst for decomposing garbage odor as described in claim 1 or 2, characterized in that, Includes the following steps: The support was impregnated in a mixed solution of Mn salt solution, Ce salt solution and Co salt solution, and then subjected to a calcination and reduction treatment in sequence to obtain the catalyst.

4. The preparation method according to claim 3, characterized in that, The TiO2-Al2O3 composite oxide support was prepared by the following method: Nitric acid was added to a mixed solution of titanium isopropoxide, aluminum isopropoxide, and solvent to carry out a hydrolysis reaction, followed by aging and a single drying process to obtain the TiO2-Al2O3 composite oxide. And / or, the molar ratio of titanium isopropoxide to aluminum isopropoxide is 19-51:20; And / or, the hydrolysis reaction is carried out at a temperature of 38-42°C; And / or, the temperature of the first drying is 115-125°C; the drying time is 10-14 hours.

5. The preparation method according to claim 3, characterized in that, In a mixed solution of Mn salt solution, Ce salt solution and Co salt solution, the concentration of the Mn salt solution is 0.4-0.6 mol / L, the concentration of the Ce salt solution is 0.2-0.4 mol / L, and the concentration of the Co salt solution is 0.3-0.9 mol / L; And / or, the Mn salt solution comprises Mn(NO3)2·4H2O; the Ce salt solution comprises Ce(NO3)3·6H2O; the Co salt solution comprises Co(NO3)2·6H2O; And / or, the liquid-to-solid ratio of the mixed solution to the carrier is 4-6 mL:1 g; And / or, the pH of the mixed solution impregnated with the carrier is 9.2-9.8; And / or, the impregnated carrier is dried; the drying temperature is 105-115°C; the drying time is 7-9 hours; And / or, the first calcination includes programmed temperature calcination; the programmed temperature calcination includes a first heating stage and a second heating stage; the heating rate of the second heating stage is greater than the heating rate of the first heating stage; the final temperature after the first calcination is 550±10℃. And / or, the reduction treatment is carried out in a hydrogen and nitrogen atmosphere; the temperature of the reduction treatment is 390-410°C; and the time of the reduction treatment is 2-4 hours. And / or, the preparation process of the catalyst further includes: after the reduction treatment, performing auxiliary agent modification; the auxiliary agent modification includes: impregnating the reduced support in an auxiliary agent raw material solution, followed by secondary calcination; And / or, the auxiliary agent raw material solution includes ammonium tungstate solution and / or lanthanum nitrate solution; the concentration of the auxiliary agent raw material solution is 0.08-0.12 mol / L; And / or, the temperature of the secondary calcination is 430-470℃; the time of the secondary calcination is 1-3h.

6. The application of the catalyst for decomposing garbage odor as described in claim 1 or 2, or the catalyst for decomposing garbage odor prepared by the preparation method described in any one of claims 3-5, in the treatment of garbage truck odor.

7. A multi-stage odor treatment method for garbage trucks, characterized in that, include: (a) Primary treatment: After mixing the exhaust gas from the garbage truck with the garbage odor, a catalytic reaction is carried out using the catalyst for decomposing garbage odor as described in claim 1 or 2, or the catalyst for decomposing garbage odor prepared by any one of the preparation methods described in claims 3-5. (b) Secondary treatment: Apply voltage to the waste odor after the treatment in step (a); (c) Tertiary treatment: Chemical adsorption of the odor from the waste after step (b).

8. The multi-stage odor treatment method for garbage trucks according to claim 7, characterized in that, The temperature for the first-stage treatment is 280-350℃; the temperature for the second-stage treatment is 150-200℃; and the temperature for the third-stage treatment is room temperature. And / or, the chemical adsorption process includes: sequentially subjecting the waste odor gas treated in step (b) to reagent treatment and adsorption treatment; And / or, the composition of the agent used in the treatment includes: ε-polylysine hydrochloride, ferric ammonium citrate, nano-ZnO quantum dots and hydroxypropyl-β-cyclodextrin; And / or, the filter element used in the adsorption treatment includes: activated carbon fiber felt loaded with Fe-MOFs.

9. The multi-stage odor treatment method for garbage trucks according to claim 7, characterized in that, The multi-stage odor treatment method for garbage trucks uses a multi-stage treatment system to treat the odor from garbage trucks. The multi-stage processing system includes a waste heat recovery and thermal oxidation module, a plasma-catalysis synergistic module, and a chemical adsorption module connected in sequence. The waste heat recovery and thermal oxidation module includes a tail gas collection subsystem and a catalytic oxidation reactor; the tail gas collection subsystem is connected to the catalytic oxidation reactor and is used to collect tail gas. The plasma-catalysis synergistic module includes a dielectric barrier discharge reactor; The chemical adsorption module includes a nano-atomization system and an adsorption filter element.

10. The multi-stage odor treatment method for garbage trucks according to claim 9, characterized in that, The exhaust gas collection subsystem includes a coaxial double-sleeve pipe; the coaxial double-sleeve pipe includes an inner pipe and an outer pipe; the inner pipe is configured as an engine exhaust pipe; the outer pipe is configured as an odor passage. The electrode structure of the dielectric barrier discharge reactor is configured as a serrated stainless steel electrode, and the dielectric layer is configured as alumina ceramic; a Pt-Pd / Al2O3 catalyst is disposed on the dielectric layer. The plasma-catalysis synergistic module also includes an ozone co-production unit. The ozone co-production unit shares the same pair of electrodes with the dielectric barrier discharge reactor. The ozone co-production unit and the dielectric barrier discharge reactor are coaxially nested and partitioned. Pure oxygen is converted into ozone in the ozone co-production zone. The nano-atomization system includes an atomizer, which is configured as a piezoelectric ceramic high-frequency atomizer.

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