Copper-based urea crystal scavenger for vehicles and preparation method of copper-based urea crystal scavenger

Abstract

The invention relates to the field of scavengers, in particular to a copper-based urea crystal scavenger for a vehicle and a preparation method of the copper-based urea crystal scavenger. The automotive copper-based urea crystal scavenger provided by the invention is prepared from the following raw materials: a copper-based catalyst, a surfactant, a foaming agent, a dispersing agent, a reducing pigment and deionized water, wherein the copper-based catalyst comprises copper acetate, the surfactant comprises AEO-10 and MOA-3PK, and the reducing pigment comprises methylene blue; the prepared automotive copper-based urea crystal scavenger is convenient to use, excellent in urea crystal melting effect and short in effective mileage, the environmental protection property of automobile running can be obviously improved after the automotive copper-based urea crystal scavenger is used, and meanwhile the effect of reducing the use cost of an automobile is remarkable.

Description

Technical Field

[0001] The invention relates to the field of scavengers, and in particular to a copper-based urea crystal scavenger for vehicles and a preparation method thereof. Background Art

[0002] Diesel and gasoline vehicles produce nitrogen oxides (NO) during operation. x These gases not only pollute the atmosphere, but may also have a significant negative impact on human health, such as causing respiratory diseases. As environmental regulations become increasingly stringent, diesel vehicles need to meet higher emission standards. In order to meet these standards, diesel engine vehicles must add urea (urea aqueous solution AUS32) according to regulations. Urea aqueous solution AUS32 can make NO x The reaction generates nitrogen and water, thereby reducing NO in the tail gas x The content of urea in diesel vehicles is reduced to make emissions more environmentally friendly and meet regulatory requirements. Specifically, the working principle of urea aqueous solution AUS32 for diesel vehicles mainly relies on selective catalytic reduction (SCR) technology. In the SCR catalytic system, urea aqueous solution AUS32 is injected into the exhaust gas aftertreatment device and decomposed into ammonia at high temperature. Ammonia undergoes an oxidation-reduction reaction with nitrogen oxides in the exhaust gas under the action of a metal-based catalyst, generating harmless nitrogen and water before being discharged. This process effectively reduces the content of harmful substances in the exhaust gas.

[0003] However, adding urea aqueous solution AUS32 will also have certain negative effects. The composition of urea aqueous solution AUS32 is calculated by mass percentage: 35% high-purity urea, 55% deionized water, and 10% methanol; urea aqueous solution AUS32 will evaporate water at high temperature (100-200°C) in the exhaust pipe, forming urea crystals; these crystals usually appear at the end of the urea injection unit, the flange, and the front end of the exhaust pipe SCR catalytic system, causing exhaust system blockage and affecting engine performance; in a cold environment, the solute in the urea aqueous solution will precipitate in the form of crystals at low temperatures, and urea crystals will also form; in addition, the use of inferior diesel, unreasonable exhaust pipe distribution, design, or improper maintenance of the SCR catalytic system will also induce the formation of urea crystals. Urea crystals will not only affect the normal operation of the engine, but also significantly reduce the utilization rate of urea, resulting in a waste of resources.

[0004] At present, the main ways to avoid urea crystallization include: using appropriate urea crystal remover or going to professional maintenance stations for thorough cleaning to ensure the normal operation of the exhaust system; regularly checking and maintaining the SCR catalytic system to ensure the normal operation of the urea pump and filter; improving vehicle use habits: avoid turning off the main power directly after the vehicle is turned off to ensure that the urea pump is completely emptied; choose high-quality urea aqueous solution and avoid using urea aqueous solution containing high aldehydes, phosphates and other impurities. However, from a cost perspective, using urea crystal remover is the most economical and quickest method.

[0005] Prior art CN105018942A discloses an environmentally friendly multi-purpose descaling liquid, the raw materials of which include trisodium phosphate, urea, fatty alcohol polyoxyethylene ether and other raw materials. According to the principle of "like dissolves like", the presence of urea in the raw material system can effectively remove urine scale, but the storage stability of urea-based removers is relatively poor, and it is difficult to ensure long-term stability during use. In addition, in the exhaust pipe, the urea aqueous solution AUS32 is in a misty state, which is difficult to dissolve urea crystals.

[0006] Therefore, there is an urgent need for a urea crystal remover with high long-term stability and excellent urea crystal ablation performance to ensure that the car has a more stable driving performance. Summary of the invention

[0007] In order to solve the above technical problems, the first aspect of the present invention provides a copper-based urea crystal scavenger for vehicles, and its preparation raw materials include: a copper-based catalyst, a surfactant, a foaming agent, a dispersant, a reducing pigment, and deionized water.

[0008] As an implementable case, the raw materials for preparing the automotive copper-based urea crystal remover include, by weight, 0.1-0.5 parts of a copper-based catalyst, 4-9 parts of a surfactant, 0.3-2 parts of a foaming agent, 3-10 parts of a dispersant, 0.1-0.5 parts of a reducing pigment, and 80-110 parts of deionized water.

[0009] Furthermore, the raw materials for preparing the automotive copper-based urea crystal remover include, by weight, 0.2 parts of a copper-based catalyst, 6 parts of a surfactant, 0.5 parts of a foaming agent, 4.5 parts of a dispersant, 0.1 parts of a reducing pigment, and 88.7 parts of deionized water.

[0010] Copper-based catalyst

[0011] As an implementable example, the copper-based catalyst is a copper-based metal inorganic salt.

[0012] Furthermore, the copper-based metal inorganic salt includes: one of copper sulfate, copper acetate, copper nitrate, copper chloride, copper carbonate, and copper tartrate.

[0013] Furthermore, the copper-based catalyst is copper acetate.

[0014] In the SCR catalytic system, copper oxide acts as a catalyst to promote the removal of nitrogen oxides (NO x ) through a reduction reaction, converting it into harmless nitrogen (N2) and water (H2O). Specifically, copper oxide has active sites on its surface that can adsorb and activate nitrogen oxide molecules, making them more susceptible to reduction reactions. These active sites help promote the combination of oxygen atoms in nitrogen oxides with ammonia, a urea reductant, to generate nitrogen and water; at the same time, in the SCR reaction, copper oxide, as a catalyst, can promote electron transfer and accelerate the redox reaction between nitrogen oxides and the reductant, thereby providing a lower energy barrier, accelerating the reaction rate, and improving the denitrification efficiency. At the same time, copper oxide as a catalyst can affect the selectivity of the reaction, making the product more inclined to generate nitrogen and water, reducing the occurrence of side reactions.

[0015] However, due to factors such as high-temperature dehydration, part of the urea aqueous solution has become urea crystals before entering the SCR catalytic system, and cannot normally catalyze the reaction of nitrogen oxides. Excessive crystals will also affect the normal driving of the car. Therefore, in the present invention, a copper-based catalyst is selected as the raw material of the urea crystal scavenger. The copper-based catalyst can generate a copper-based complex through a series of complex reactions under the high-temperature system when the engine is working, and then convert it into copper oxide molecules to melt the urea crystals, so that it participates in the catalytic reaction of nitrogen oxides before entering the SCR catalytic system. At the same time, copper oxide cooperates with the SCR catalytic system to reduce the content of harmful gases in automobile exhaust.

[0016] In addition to copper-based catalysts, the inventors found in the early research and development process that titanium-based catalysts and vanadium-based catalysts can also efficiently ablate urea crystals. The ablation and catalytic effects of vanadium-based catalysts are even better than those of copper-based catalysts. This is mainly due to the fact that vanadium oxide has a strong affinity for NO. x It has high selectivity and can maintain high catalytic activity in a wide temperature range. At the same time, vanadium oxide has a certain sulfur resistance and can be used in fuels containing a certain amount of sulfur. However, inhalation of vanadium oxide dust can cause respiratory irritation and damage, and symptoms such as coughing, wheezing, shortness of breath, and chest tightness can occur. Long-term exposure to vanadium oxide may also lead to diseases such as lung cancer, which can cause serious harm to human health. Therefore, based on safety and environmental protection considerations, copper-based catalysts are safer, more reliable, and less polluting.

[0017] For copper-based catalysts, copper sulfate, copper acetate, copper nitrate, copper chloride, and copper carbonate can all generate copper oxide to promote the conversion of nitrogen oxides. However, if copper sulfate, copper nitrate, etc. are selected as copper-based catalysts, copper-based complex intermediates will not be generated, but copper salt precipitates will be directly formed, which cannot enter the exhaust system with the urea aqueous solution AUS32, thereby affecting its catalytic effect on nitrogen oxides. Therefore, the present invention preferably uses copper acetate as the copper-based catalyst, which has a more excellent catalytic effect.

[0018] Surfactants

[0019] As an implementable case, the surfactant includes: a first surfactant fatty alcohol polyoxyethylene ether and a second surfactant fatty alcohol polyoxyethylene ether derivative.

[0020] Furthermore, the mass ratio of the fatty alcohol polyoxyethylene ether to the fatty alcohol polyoxyethylene ether derivative is (3-6):(1-3).

[0021] As an implementable case, the fatty alcohol polyoxyethylene ether includes: one of AEO-9, AEO-10, and AEO-12.

[0022] Furthermore, the fatty alcohol polyoxyethylene ether is AEO-10.

[0023] Fatty alcohol polyoxyethylene ether is a nonionic surfactant with good wetting, emulsifying, dispersing and solubilizing properties. When used in urea crystal scavengers, it can effectively dissolve urea crystals, avoid their impact on engine operation, and improve the utilization rate of urea. However, different types of fatty alcohol polyoxyethylene ethers have different hydrophilic and lipophilic properties, which will also have a certain impact on the dissolution of urea crystals. In addition to its emulsifying, dispersing and dissolving properties, AEO-10 ​​also has certain foaming properties. It can work together with the foaming agent to increase the specific surface area of ​​the urea aqueous solution droplets sprayed into the SCR catalytic system, making the sprayed droplets into a hollow bubble structure, while reducing the amount of urea crystal scavenger, maintaining the product's urea crystal dissolution performance.

[0024] However, as the usage time increases, the fatty alcohol polyoxyethylene ether dissolved in the urea aqueous solution will volatilize, the effective content will decrease, and the long-term stability of the product's urea crystal ablation will be significantly affected.

[0025] As an implementable case, the fatty alcohol polyoxyethylene ether derivative includes: one or more of fatty alcohol polyoxyethylene ether potassium phosphate, fatty alcohol polyoxyethylene ether calcium phosphate, fatty alcohol polyoxyethylene ether magnesium phosphate, fatty alcohol polyoxyethylene ether iron phosphate, fatty alcohol polyoxyethylene ether ammonium phosphate, and fatty alcohol polyoxyethylene ether sodium phosphate.

[0026] Furthermore, the fatty alcohol polyoxyethylene ether derivative is fatty alcohol polyoxyethylene ether potassium phosphate (MOA-3PK).

[0027] As the content of fatty alcohol polyoxyethylene ether decreases significantly with the increase of product use time, fatty alcohol polyoxyethylene ether potassium phosphate is added in the present invention. The main reason is that the free fatty alcohol polyoxyethylene ether groups in the fatty alcohol polyoxyethylene ether potassium phosphate are released, which can make up for the influence caused by the decrease of fatty alcohol polyoxyethylene ether content, so that the content of fatty alcohol polyoxyethylene ether in the system maintains a dynamic balance, and improves the long-term stability of the product. At the same time, the inventors have found that the content of fatty alcohol polyoxyethylene ether potassium phosphate should not be added too high, mainly because the fatty alcohol polyoxyethylene ether potassium phosphate and fatty alcohol polyoxyethylene Ethers exist in a chemical dynamic equilibrium in the system, but they also have a certain degree of competitiveness. If the amount of fatty alcohol polyoxyethylene ether potassium phosphate added is too high, it will affect the ablation effect of fatty alcohol polyoxyethylene ether. At the same time, excessive use of fatty alcohol polyoxyethylene ether potassium phosphate is likely to produce new fatty alcohol polyoxyethylene ether phosphate salt impurity precipitation, affecting the use effect of the product. Therefore, limiting the mass ratio of fatty alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether derivative to (3-6): (1-3) is the most preferred technical solution, which can ensure that the product has excellent urea crystal ablation performance and high long-term stability.

[0028] Dispersants

[0029] Preferably, the dispersant comprises: one or more of polyethylene glycol, isopropanol, butanol, ethanol, propylene glycol, and butanediol.

[0030] Furthermore, the dispersant includes a first dispersant of polyethylene glycol and a second dispersant of isopropanol.

[0031] Furthermore, the mass ratio of the polyethylene glycol to isopropanol is (5-10):1.

[0032] As an implementable case, the polyethylene glycol includes one or more of PEG-200, PEG-300, PEG-400, PEG-600, PEG-800, and PEG-1000.

[0033] Furthermore, the polyethylene glycol is PEG-400.

[0034] In order to make the dispersion of various raw material components in the system more uniform, the present invention adds specific dispersants, including PEG-400 and isopropanol. After PEG-400 and isopropanol are compounded, the surface tension of the liquid can be reduced, so that the diameter of the urea aqueous solution droplets injected into the SCR catalytic system is reduced, which is not only beneficial to increase the specific surface area of ​​the droplets, but also can maintain a high ablation effect of urea crystals while ensuring a low dosage of the urea crystal scavenger.

[0035] Foaming agent

[0036] As an implementable case, the foaming agent includes: one or more of cocamidopropyl betaine, sodium lauryl sulfate, sodium lauroyl sarcosinate, cocamidopropyl amine oxide, dodecyl dimethyl betaine, and alkyl glucoside.

[0037] Furthermore, the foaming agent is cocamidopropyl betaine (CAB-35).

[0038] The cocamidopropyl betaine molecule contains a hydrophobic long-chain alkyl group and a hydrophilic carboxyl group and an amino group. When cocamidopropyl betaine is dissolved in water, its hydrophobic group will gather in the water to form a mass, and these masses can adsorb and wrap gas molecules to form bubbles. At the same time, the hydrophilic group of cocamidopropyl betaine forms a hydrogen bond with water molecules, so that the bubble surface is covered by a stable layer of water molecules, thereby preventing the bubble from bursting. In the present invention, the foaming agent cocamidopropyl betaine can act together with fatty alcohol polyoxyethylene ether to improve the specific surface area of ​​the urea aqueous solution droplets sprayed into the SCR catalytic system, so that the droplets sprayed into the hollow bubble structure are reduced. On the basis of the amount of urea crystal scavenger, the ablation performance of urea crystals is further improved.

[0039] Reducing pigments

[0040] As an implementable example, the reducing pigment includes: one or more of methylene blue, methylene green, methyl blue, methyl orange, toluidine blue, Nile blue, neutral red, and crystal violet.

[0041] Furthermore, the reducing pigment includes: one of methylene blue and methylene green.

[0042] Furthermore, the reducing pigment is methylene blue.

[0043] Methylene blue, as a pigment, makes urea crystal scavenger products easier to identify; more importantly, methylene blue is a dye with redox properties, and its molecular structure contains functional groups that can coordinate with metal ions. In the present invention, copper-based catalyst copper acetate is selected, and when added to an aqueous solution, free copper ions (Cu2+) are formed. Cu2+ can coordinate with the functional groups in the methylene blue molecules to form a stable copper-based complex. Then, using a high-temperature heat source of more than 200°C in the exhaust pipe, the copper-based complex will further react to generate copper hydroxide, which is then decomposed into copper oxide molecules, which can be used as a catalyst to reduce NO before the urea crystallization area is generated. X The compounds and urea are catalyzed to further improve the utilization rate of urea, avoid engine failure due to urea crystallization, and greatly improve the environmental protection index of vehicle exhaust.

[0044] The second aspect of the present invention provides a method for preparing a copper-based urea crystal scavenger for vehicles, comprising: mixing raw materials to obtain.

[0045] Furthermore, the preparation method of the automotive copper-based urea crystal remover comprises:

[0046] S1. Dilute the first dispersant PEG-400 with deionized water and stir for 5-10 minutes;

[0047] S2, add the first surfactant AEO-10, and stir for 5-10 minutes;

[0048] S3, add the second dispersant isopropanol, and stir for 5-10 minutes;

[0049] S4, add the second surfactant MOA-3PK and stir for 5-10 minutes;

[0050] S5, add copper-based catalyst copper acetate, and stir for 5-20 minutes;

[0051] S6, add the foaming agent CAB-35 and stir for 5-10 minutes;

[0052] S7. Add reducing pigment methylene blue and stir for 5-10 minutes.

[0053] The vehicle copper-based urea crystal remover prepared by the present invention and the urea aqueous solution AUS32 are mixed in a volume ratio of 1:500 and added into a vehicle urea tank. The use is quick and convenient. A small amount of the product can dissolve urea crystals without changing the existing vehicle structure and equipment. The urea crystals can be continuously used after being dissolved, or can be stopped.

[0054] Beneficial Effects

[0055] (i) The present invention selects a copper-based catalyst as one of the raw materials, which can work together with methylene blue to improve the catalytic efficiency of nitrogen oxides and the utilization rate of urea. In addition, the copper-based catalyst is relatively safe, environmentally friendly, and stable.

[0056] (ii) The present invention selects fatty alcohol polyoxyethylene ether and fatty alcohol polyoxyethylene ether derivatives for compounding, which can improve the long-term stability of the urea crystal scavenger.

[0057] (III) The present invention selects a compound of polyethylene glycol and isopropanol as a dispersant, which can further improve the product's ablative property against urea crystals.

[0058] (IV) The present invention selects cocamidopropyl betaine as a foaming agent, which can work together with fatty alcohol polyoxyethylene ether to increase the specific surface area of ​​urea aqueous solution droplets sprayed into the SCR catalytic system, so that the sprayed droplets have a hollow bubble structure, thereby further improving the ablation performance of the product on the basis of reducing the amount of urea crystal scavenger used.

[0059] (V) The urea crystal scavenger prepared by the present invention is easy to use. The product and the urea aqueous solution can be mixed at a volume ratio of 1:500. The copper ion concentration after mixing is lower than the national requirement for copper ions in domestic water, and will not pollute the environment. It has high safety. The effective mileage of the urea crystal scavenger is less than 2500km, the effect is fast, and it has high long-term stability. The links from production to use are more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a schematic diagram of the use principle of the urea crystal scavenger in Example 1 of the present invention.

[0061] Figure 2 This is a schematic diagram of urea crystals at the front end of the SCR catalyst of the exhaust pipe of a vehicle with urea crystal failure before using the urea crystal scavenger in Example 1 of the present invention.

[0062] Figure 3 This is a schematic diagram of urea crystals at the front end of the SCR catalyst of the exhaust pipe of a vehicle with urea crystal failure after the urea crystal scavenger of Example 1 of the present invention has been used for 12 hours.

[0063] Figure 4 This is a schematic diagram of urea crystals at the front end of the SCR catalyst of the exhaust pipe of a vehicle with urea crystal failure after the urea crystal scavenger of Example 1 of the present invention has been used for 24 hours.

[0064] Figure 5 This is a schematic diagram of urea crystals at the front end of the SCR catalyst of the exhaust pipe of a vehicle with urea crystal failure after the urea crystal scavenger of Example 1 of the present invention has been used for 48 hours. DETAILED DESCRIPTION

[0065] In the following implementation cases:

[0066] Copper acetate was purchased from Xiamen Haibiao Technology Co., Ltd.

[0067] PEG-400 was purchased from Guangzhou Nanjia Chemical Co., Ltd.

[0068] AEO-10 ​​was purchased from Shanghai Huijun Chemical Co., Ltd.

[0069] MOA-3PK was purchased from Shanghai Huijun Chemical Co., Ltd.

[0070] Isopropyl alcohol was purchased from Shanghai Kelong Chemical Co., Ltd.

[0071] CAB-35 was purchased from Shandong Yousuo Chemical Technology Co., Ltd.

[0072] Methylene blue (CAS: 7220-79-3) was purchased from Zhengzhou Honghai Dye Chemical Co., Ltd.

[0073] Deionized water was purchased from Shanghai Jingchun Water Treatment Technology Co., Ltd.

[0074] Example 1

[0075] The first aspect of this example provides a copper-based urea crystal scavenger for automobiles, wherein the raw materials for its preparation are calculated by weight and include: 0.2 parts of copper acetate, 4 parts of AEO-10, 2 parts of MOA-3PK, 4 parts of PEG-400, 0.5 parts of isopropanol, 0.5 parts of CAB-35, 0.1 parts of methylene blue, and 88.7 parts of deionized water.

[0076] The second aspect of this example provides a method for preparing a copper-based urea crystal remover for a vehicle, comprising:

[0077] S1. Dilute PEG-400 with deionized water and stir at 30°C for 5 min.

[0078] S2, add AEO-10 ​​and stir at 25°C for 5 min;

[0079] S3, add isopropanol and stir at 25°C for 5 min;

[0080] S4, add MOA-3PK, and stir at 25°C for 5 min;

[0081] S5. Add copper acetate and stir at 25°C for 10 min.

[0082] S6, add CAB-35 and stir at 20°C for 5 min;

[0083] S7. Add methylene blue and stir at 25°C for 10 min.

[0084] Example 2

[0085] In the first aspect of this example, a urea crystal scavenger is provided, and the raw materials for its preparation, calculated by weight, include: 4 parts of AEO-10, 2 parts of MOA-3PK, 4 parts of PEG-400, 0.5 parts of isopropanol, 0.5 parts of CAB-35, and 89 parts of deionized water.

[0086] The second aspect of this example provides a method for preparing a urea crystal scavenger, comprising:

[0087] S1. Dilute PEG-400 with deionized water and stir at 30°C for 5 min.

[0088] S2, add AEO-10 ​​and stir at 25°C for 5 min;

[0089] S3, add isopropanol and stir at 25°C for 5 min;

[0090] S4, add MOA-3PK, and stir at 25°C for 5 min;

[0091] S5. Add CAB-35 and stir at 20°C for 5 minutes to obtain the product.

[0092] Example 3

[0093] In a first aspect of this example, a urea crystal scavenger is provided, and the raw materials for preparing the urea crystal scavenger include, by weight, 4 parts of AEO-10 ​​and 96 parts of deionized water.

[0094] The second aspect of this example provides a method for preparing a urea crystal scavenger, comprising: mixing AEO-10 ​​and deionized water, and stirring at 25° C. for 10 minutes.

[0095] Performance Testing

[0096] 1. Average effective mileage test

[0097] After eliminating the mechanical and electronic faults of the vehicle with urea crystallization fault, the product of Example 1-3 was fully mixed with the automotive urea aqueous solution AUS32 at a volume ratio of 1:500, and added to the urea tank of the faulty vehicle for test transportation. Figure 1 As shown, it is effective until the fault light is eliminated. Each group of tests is conducted 4 times, and the average value is taken as the average effective mileage. The reaction test results are detailed in Table 1.

[0098] There are two test routes, one is the Guangzhou-Beijing two-way route, that is, Guangzhou to Beijing; the other is the Guangzhou-Chengdu two-way route, recorded as Guangzhou to Chengdu. The driving altitude of the Guangzhou-Beijing route is basically the same, and the driving altitude of the Guangzhou-Chengdu route is from low altitude to high altitude.

[0099] The test vehicle is Scania G420. The engines of all Scania G420 vehicles are exactly the same, which can avoid the experimental errors caused by different manufacturers and models of the invention.

[0100] Table 1

[0101]

[0102] It can be seen from Table 1 that the urea crystal remover prepared in Example 1 has the shortest average effective mileage and has excellent urea crystal ablation effect. In addition, it can be seen from Table 1 that in the same group of experiments, the effective mileage of the Guangzhou-Beijing line is shorter than that of the Guangzhou-Chengdu line. This is mainly because the altitude gradually increases from Guangzhou to Chengdu, the oxygen content in the air gradually decreases, the engine combustion performance decreases to a certain extent, and more pollutants are generated. Therefore, the effective mileage of the Guangzhou-Chengdu line is longer than that of the Guangzhou-Beijing line.

[0103] 2. Schematic diagram of urea crystal ablation

[0104] Test Example 1: The urea crystals in the front section of the SCR catalyst of the exhaust pipe of the vehicle with urea crystallization fault were observed using an endoscope before and after the product was added. The test results are as follows: Figure 2-5 shown.

[0105] in, Figure 2 This is a schematic diagram of urea crystals at the front end of the SCR catalyst of the exhaust pipe of a vehicle with urea crystal failure before the urea crystal remover of Example 1 is used; Figure 3 This is a schematic diagram of urea crystals at the front end of the SCR catalyst of the exhaust pipe of a vehicle with urea crystal failure after the urea crystal scavenger of Example 1 has been used for 12 hours; Figure 4 This is a schematic diagram of urea crystals at the front end of the SCR catalyst of the exhaust pipe of a vehicle with urea crystal failure after the urea crystal scavenger of Example 1 has been used for 24 hours; Figure 5 This is a schematic diagram of urea crystals at the front end of the SCR catalyst in the exhaust pipe of a vehicle with urea crystal failure after the urea crystal scavenger of Example 1 has been used for 48 hours.

[0106] from Figure 2-5 It can be seen that the use of the urea crystal scavenger of Example 1 can effectively reduce the amount of urea crystals in the exhaust pipe SCR catalyst of a vehicle with urea crystal failure.

Claims

1. A copper-based urea crystal remover for automobiles, characterized in that: The preparation raw materials include: copper-based catalyst, surfactant, foaming agent, dispersant, reducing pigment and deionized water.

2. The automotive copper-based urea crystal remover according to claim 1, characterized in that: The raw materials for preparing the automotive copper-based urea crystal remover include, by weight, 0.1-0.5 parts of a copper-based catalyst, 4-9 parts of a surfactant, 0.3-2 parts of a foaming agent, 3-10 parts of a dispersant, 0.1-0.5 parts of a reducing pigment, and 80-110 parts of deionized water.

3. The automotive copper-based urea crystal remover according to claim 1, characterized in that: The copper-based catalyst is a copper-based metal inorganic salt, which is one of copper sulfate, copper acetate, copper nitrate, copper chloride, copper carbonate and copper tartrate.

4. The automotive copper-based urea crystal remover according to claim 1, characterized in that: The surfactant comprises: a first surfactant, fatty alcohol polyoxyethylene ether, and a second surfactant, fatty alcohol polyoxyethylene ether derivative.

5. The automotive copper-based urea crystal remover according to claim 4, characterized in that: The mass ratio of the fatty alcohol polyoxyethylene ether to the fatty alcohol polyoxyethylene ether derivative is (3-6): (1-3).

6. The automotive copper-based urea crystal remover according to claim 5, characterized in that: The fatty alcohol polyoxyethylene ether includes one of AEO-9, AEO-10 ​​and AEO-12.

7. The automotive copper-based urea crystal remover according to claim 5, characterized in that: The fatty alcohol polyoxyethylene ether derivatives include: one or more of fatty alcohol polyoxyethylene ether potassium phosphate, fatty alcohol polyoxyethylene ether calcium phosphate, fatty alcohol polyoxyethylene ether magnesium phosphate, fatty alcohol polyoxyethylene ether iron phosphate, fatty alcohol polyoxyethylene ether ammonium phosphate, and fatty alcohol polyoxyethylene ether sodium phosphate.

8. The automotive copper-based urea crystal remover according to any one of claims 1 to 7, characterized in that: The dispersant includes one or more of polyethylene glycol, isopropanol, butanol, ethanol, propylene glycol and butanediol.

9. The automotive copper-based urea crystal remover according to claim 1, characterized in that: The reducing pigment includes one or more of methylene blue, methylene green, methyl blue, methyl orange, toluidine blue, Nile blue, neutral red and crystal violet.

10. A method for preparing the automotive copper-based urea crystal scavenger according to any one of claims 1 to 9, characterized in that: include: Mix the raw materials and you're done.

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