CN104675483A - Low-freezing-point nitric oxide reducing agent and preparation method thereof - Google Patents
Low-freezing-point nitric oxide reducing agent and preparation method thereof Download PDFInfo
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- CN104675483A CN104675483A CN201510015958.2A CN201510015958A CN104675483A CN 104675483 A CN104675483 A CN 104675483A CN 201510015958 A CN201510015958 A CN 201510015958A CN 104675483 A CN104675483 A CN 104675483A
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Abstract
The invention provides a low-freezing-point nitric oxide reducing agent and a preparation method thereof. The low-freezing-point nitric oxide reducing agent consists of, by mass, 20%-32.5% of urea, 5%-10% of dimethyl sulfoxide, 40%-55% of pure water and one or more of 10%-20% of acid amide, amides and low molecular alcohols. The preparation method comprises the following steps of preparing raw materials, performing full mixing at the temperature ranging from 10 DEG C to 30 DEG C till all raw materials are completely dissolved into a water solution and mixed evenly, using a filter element with the filter accuracy ranging from 0.5 mum to 5 mum and filtering the raw material water solution under the pressure of 0.2-1 MPa to obtain a finished product. The anti-freezing agent raw materials have the advantages of being safe and easy to obtain, good in anti-freezing effect, non-toxic, harmless and the like. The freezing point of the reducing agent is greatly reduced, the problems of low-temperature crystallization and icing are solved, the anti-freezing performance of the nitric oxide reducing agent can be remarkably improved, and the freezing point can be lower than subzero 25 DEG C. A test shows that after engine exhaust gas is filled into an SCR aftertreatment system of the low-freezing-point nitric oxide reducing agent to be treated, the exhaust gas emission can be up to the national IV standard.
Description
Technical field
The present invention relates to diesel motor exhaust reprocessing field, specifically a kind of lower freezing point NOx reducing agent and preparation method thereof.
Background technique
In recent years, along with the frequent appearance of China's various places haze weather, increasingly sharpening of Chinese government's environmental protection pressure.The improvement making the motor vehicle discharged tail gas of main contributions for haze weather pollution sources is also accelerated, and after Beijing takes the lead in implementing state IV emission standard in March, 2008, Motor Vehicle state IV standards is implemented in the cities such as Shanghai, Shenzhen and Guangzhou, Xi'an in succession.The city of carrying out state four emission standard for nearly 2 years increases day by day, estimates that country in 2015 will enforce Motor Vehicle state IV emission standard comprehensively.
According to the production technology of diesel engines at present, diesel-oil vehicle wants to reach state IV emission standard, except improving the emission controls by improving combustion measure such as fuel injection system, Optimizing Combustion process, also must increase the outer after-treatment device of machine.On our times, the exhaust aftertreatment technology path of main flow is SCR route.Adopt the diesel engine of SCR technology first to optimize in-cylinder combustion, reduce the discharge of particulate matter, then pass through SCR technology to high NO
xthe tail gas of content carries out reprocessing.Due to adopt state IV Fuel Economy of SCR technology better, little to engine modification than EGR technology, to fuel oil and machine oil require lower, there is advantage, SCR catalyst good endurance and there is not the risk of catalyst converter blocking in technology upgrading continuity, therefore SCR technology is the large diesel engine energy-conserving and emission-cutting technology route of applicable China's national situation.And for SCR system, NOx reducing agent-urea for vehicle solution is then that its performance effect must be prepared, urea for vehicle solution deposits in special holding vessel, with pressurized air, urea liquid is sprayed the motor exhaust (about 300 DEG C ~ 500 DEG C of thermotropism, meet reduction reaction conditions), produce the ammonia that reduction efficiency is high after this vaporizer, under the effect of the NOx catalyzer in SCR catalyst in ammonia and tail gas, redox reaction occurs, be converted into harmless water vapor and N
2.
China has started to promote the diesel-oil vehicle meeting state four discharge adopting SCR technology, and supply, the sale of the urea for vehicle solution of the car needs of the type also begin to take shape.Traditional urea for vehicle solution is the aqueous solution containing urea 32.5%, and the freezing point of this product is ﹣ 11.5 DEG C, will crystallization lower than this temperature product, actual use in can go up completely when ﹣ 20 DEG C.Because China is vast in territory, in especially winter, various places temperature difference is larger.Freezing point be ﹣ 11.5 DEG C urea for vehicle solution the north or other extremely frigid zones, do not have corresponding measure to use.
At present, the method solving urea for vehicle crystallization condensation mainly takes Insulation to SCR system on the one hand, is then by adding antifreezing solution in urea for vehicle on the one hand, reduces freezing point, prevents solution crystallization coagulation to play.
Retrieval finds, the achievement in research improving reductant solution freezing point comprises the patent JP20090031713 " ANTIFREEZING UREA SOLUTION FOR UREA SCR SYSTEM AND UREA SCR SYSTEM USING THE SAME " of Japan, European product Denoxium-30 and China patent CN201110134706.3 " a kind of low-temperature urea reducing agent composition ", CN201110134698.2 " a kind of ultralow-temperature urea reducing agent composition ".What Japan Patent JP20090031713 adopted is that the alcohols of C1 ~ C7 is as freezing point improver, its adding quantity ratio of the adding quantity of the alcohols of (alcohols+urea of water+C1 ~ C7)/C1 ~ C7 limits, ratio is 7/1, calculate in theory, suppose that the density of ethanol is 0.789kg/L at 20 DEG C of temperature, calculate that the adding quantity of alcohols is less than 10%wt; If adopt methyl alcohol or ethanol to implement, actual detection shows the ﹣ 30 DEG C that its freezing point can not reach described, and supposition should be with the addition of isopropanol or ethylene glycol, or inventor has a mind to imply certain composition or addition; Inventor about this point JP20090031713 patent does not describe.The low-temperature urea reducing agent product Denoxium-30 in Europe adopts the aqueous solution of 20% urea and 26% ammonium formate as reducing agent, product freezing point is between ﹣ 26 DEG C ~ ﹣ 30 DEG C, use in the extremely cold north and still have certain narrow limitation, in addition, the relative this patent high cost of this product.
China patent CN 201110134706.3 and CN 201110134698.2 is all by adding the materials such as ammonium class, amide-type, alcohols to reach the object reducing freezing point in urea for vehicle.The relative this patent complicated component of this patent, increases production difficulty.In addition, alcohol reagent has volatility mostly, and the poorly sealed or long-time uncovered placement of product not only can affect quality of product, also can produce certain pollution to ambient air.
Summary of the invention
The object of the invention is to: provide a kind of for NOx reducing agent and preparation method thereof in diesel motor exhaust under low temperature.
The technical solution adopted in the present invention is:
A kind of lower freezing point NOx reducing agent, its component and mass percent are: the urea of 20% ~ 32.5%, the dimethyl sulfoxide (DMSO) of 5% ~ 10%, one or more compositions in the pure water of 40% ~ 55% and the acyl ammonium class of 10% ~ 20%, ammonium class, low molecule alcohols.
Described urea need meet the technical requirements of the special urea of AUS 32 in GB 29518-2013 " diesel engine NOx reducing agent aqueous solution of urea (AUS 32) " standard.
Described pure water need meet the technical requirements to pure water in GB 29518-2013 " diesel engine NOx reducing agent aqueous solution of urea (AUS 32) " standard.
Described dimethyl sulfoxide (DMSO), ammonium class, amide-type and low molecule alcohols are the product analyzing pure above grade.
The preparation method of described lower freezing point NOx reducing agent, comprises following concrete steps:
(1) raw material is assorted by described component and mass percent, fully stir at the temperature of 10 ~ 30 DEG C, until all raw materials are dissolved as the aqueous solution completely, and mix;
(2) filter precision is used to be the filter core of 0.5 ~ 5 μm, under the pressure of 0.2 ~ 1MPa, after being filtered by the aqueous solution of raw material that step (1) obtains, to obtain lower freezing point NOx reducing agent solution.
The beneficial effect that the present invention produces is:
The present invention improves component and the preparation method of existing NOx reducing agent, compared with the prior art, and the features such as this NOx reducing agent has antifreezing solution materials safety and is easy to get, good freezing protection effect, nontoxic; The present invention reduces reducing agent freezing point greatly, and solve low temperature crystallization and ice formation issues, can significantly improve NOx reducing agent resistance to frost, freezing point can reach ﹣ less than 25 DEG C; Product of the present invention carries out ETC, ESC working condition measurement on diesel engine machine frame, and motor exhaust is after the SCR aftertreatment system process of this product of annotating, and exhaust emissions can reach state four standard.
Embodiment
The invention discloses a kind of production method for NOx reducing agent in diesel motor exhaust under low temperature, this lower freezing point NOx reducing agent composition, by urea, dimethyl sulfoxide (DMSO), one or more compositions in pure water and acyl ammonium class, ammonium class, low molecule alcohols.Wherein urea accounts for 20% ~ 32.5% of mixture gross mass, and dimethyl sulfoxide (DMSO) accounts for 5% ~ 10% of mixture gross mass, and ammonium class, amide-type and alcohols account for 10% ~ 20% of mixture gross mass, and water accounts for 40% ~ 55% of mixture gross mass.
In invention composition component:
The purity requirement of urea is higher, need meet the technical requirements of the special urea of AUS 32 in GB 29518-2013 " diesel engine NOx reducing agent aqueous solution of urea (AUS 32) " standard.
Dimethyl sulfoxide (DMSO) is the product analyzing pure above grade, and molecular formula is (CH
3)
2sO, decomposes, spontaneous combustion more than 300 DEG C under the high temperature of 140 ~ 150 DEG C, generates CO
2, H
2o and SO
2.
Ammonium class, amide-type and low molecule alcohols are the product analyzing pure above grade.If Some substitute urea decomposition is discharged ammonia by adding portion ammonium class, amide-type product, corresponding minimizing amount of urea.Ammonium class, amide-type final product are nitrogen, carbon dioxide.Ammonium class, amide-type and alcohols can be used alone one, also can multiple combination, select according to cost, character, effect; Generally can the material of the low molecular weight such as formic acid ammonium, formamide, methyl alcohol, ethylene glycol, diethylene glycol, ethanol, isopropanol, glycerine and low carbon content.
The purity requirement of component pure water is also higher, need reach or be better than the technical requirements to pure water in GB 29518-2013 " diesel engine NOx reducing agent aqueous solution of urea (AUS 32) " standard.
After each component is mixed in proportion, even if lower freezing point NOx reducing agent product of the present invention.The existence of dimethyl sulfoxide (DMSO), ammonium class, amide-type and alcohols additive does not affect the safety in utilization of nitrogen oxide aqueous solution of urea.
The preparation method of lower freezing point NOx reducing agent of the present invention, comprises following concrete steps:
(1) raw material is assorted by described component and mass percent, fully stir at the temperature of 10 ~ 30 DEG C, until all raw materials are dissolved as the aqueous solution completely, and mix.Concrete: because acyl ammonium class, ammonium class, low molecule alcohols and dimethyl sulfoxide (DMSO) are liquid, soluble in water; Therefore, in actual fabrication process, after urea solid all dissolves, can stop stirring.
(2) filter precision is used to be the filter core of 0.5 ~ 5 μm, under the pressure of 0.2 ~ 1MPa, after being filtered by the aqueous solution of raw material that step (1) obtains, to obtain lower freezing point NOx reducing agent solution.
embodiment 1
With satisfactory urea component 325kg, analyze pure above rank dimethyl sulfoxide (DMSO) 100kg, methyl alcohol 100kg, pure water 475kg, each component being mixed, be stirred to urea and dissolve completely, is the filter core of 0.5 μm with filter precision, after 0.2Mpa filtered under pressure, be composition solution of the present invention.
After measured, mixture solution freezing point ﹣ 27 DEG C, slightly ammonia taste, clear appearance is transparent.The indexs such as metal ion, biuret, aldehydes, phosphate, undissolved substance, basicity all meet the demands.Separate out without crystal under ﹣ more than 25 DEG C temperature environments, after room temperature lower seal stores 6 months, outward appearance, smell change without sensory perceptible, and reducing property meets the requirements.
Product is that 336 horsepowers of (discharge capacity 9.726L) diesel engine machine frames carry out ETC, ESC working condition measurement through power, and motor exhaust is after the SCR aftertreatment system process of this product of annotating, and exhaust emissions can reach state four standard.
embodiment 2
With satisfactory urea component 200kg, analyze pure above rank dimethyl sulfoxide (DMSO) 50kg, ammonium class, acid amides and low molecule alcohols 200kg(be wherein: ammonium formate 50kg, formamide 150kg), pure water 550kg, each component being mixed, be stirred to urea and dissolve completely, is the filter core of 2.5 μm with filter precision, after 0.6Mpa filtered under pressure, be composition solution of the present invention.
After measured, mixture solution freezing point ﹣ 25 DEG C, slightly ammonia taste, clear appearance is transparent.The indexs such as metal ion, biuret, aldehydes, phosphate, undissolved substance, basicity all meet the demands.Separate out without crystal under ﹣ more than 25 DEG C temperature environments, after room temperature lower seal stores 6 months, outward appearance, smell change without sensory perceptible, and reducing property meets the requirements.
Product is that 336 horsepowers of (discharge capacity 9.726L) diesel engine machine frames carry out ETC, ESC working condition measurement through power, and motor exhaust is after the SCR aftertreatment system process of this product of annotating, and exhaust emissions can reach state four standard.
embodiment 3
With satisfactory urea component 258kg, analyze pure above rank dimethyl sulfoxide (DMSO) 100kg, ammonium class, acid amides and low molecule alcohols 150kg(be wherein: diethylene glycol 50kg, formamide 100kg), pure water 492kg, each component being mixed, be stirred to urea and dissolve completely, is the filter core of 5 μm with filter precision, after 1Mpa filtered under pressure, be composition solution of the present invention.
After measured, mixture solution freezing point ﹣ 25 DEG C, slightly ammonia taste, clear appearance is transparent.The indexs such as metal ion, biuret, aldehydes, phosphate, undissolved substance, basicity all meet the demands.Separate out without crystal under ﹣ more than 25 DEG C temperature environments, after room temperature lower seal stores 6 months, outward appearance, smell change without sensory perceptible, and reducing property meets the requirements.
Product is that 336 horsepowers of (discharge capacity 9.726L) diesel engine machine frames carry out ETC, ESC working condition measurement through power, and motor exhaust is after the SCR aftertreatment system process of this product of annotating, and exhaust emissions can reach state four standard.
embodiment 4
With satisfactory urea component 325kg, analyze pure above rank dimethyl sulfoxide (DMSO) 100kg, ammonium class, acid amides and low molecule alcohols 175kg(be wherein: ethanol 125kg, isopropanol 50kg), pure water 400kg, each component being mixed, be stirred to urea and dissolve completely, is the filter core of 0.6 μm with filter precision, after 0.6Mpa filtered under pressure, be composition solution of the present invention.
After measured, mixture solution freezing point ﹣ 25 DEG C, slightly ammonia taste, clear appearance is transparent.The indexs such as metal ion, biuret, aldehydes, phosphate, undissolved substance, basicity all meet the demands.Separate out without crystal under ﹣ more than 25 DEG C temperature environments, after room temperature lower seal stores 6 months, outward appearance, smell change without sensory perceptible, and reducing property meets the requirements.
Product is that 336 horsepowers of (discharge capacity 9.726L) diesel engine machine frames carry out ETC, ESC working condition measurement through power, and motor exhaust is after the SCR aftertreatment system process of this product of annotating, and exhaust emissions can reach state four standard.
Claims (5)
1. a lower freezing point NOx reducing agent, it is characterized in that, its component and mass percent are: the urea of 20% ~ 32.5%, the dimethyl sulfoxide (DMSO) of 5% ~ 10%, one or more compositions in the pure water of 40% ~ 55% and the acyl ammonium class of 10% ~ 20%, ammonium class, low molecule alcohols.
2. lower freezing point NOx reducing agent according to claim 1, it is characterized in that, described urea need meet the technical requirements of the special urea of AUS 32 in GB 29518-2013 " diesel engine NOx reducing agent aqueous solution of urea (AUS 32) " standard.
3. lower freezing point NOx reducing agent according to claim 1, it is characterized in that, described pure water need meet the technical requirements to pure water in GB 29518-2013 " diesel engine NOx reducing agent aqueous solution of urea (AUS 32) " standard.
4. lower freezing point NOx reducing agent according to claim 1, it is characterized in that, described dimethyl sulfoxide (DMSO), ammonium class, amide-type and low molecule alcohols are the product analyzing pure above grade.
5. the preparation method of lower freezing point NOx reducing agent according to claim 1, is characterized in that, comprise following concrete steps:
(1) raw material is assorted by described component and mass percent, fully stir at the temperature of 10 ~ 30 DEG C, until all raw materials are dissolved as the aqueous solution completely, and mix;
(2) filter precision is used to be the filter core of 0.5 ~ 5 μm, under the pressure of 0.2 ~ 1MPa, after being filtered by the aqueous solution of raw material that step (1) obtains, to obtain lower freezing point NOx reducing agent solution.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105498537A (en) * | 2015-11-30 | 2016-04-20 | 许昌学院 | Low-temperature diesel exhaust reducing agent and preparation method thereof |
| CN107081066A (en) * | 2017-05-02 | 2017-08-22 | 盘锦鑫安源化学工业有限公司 | A kind of diesel motor exhaust scavenging solution of nodeless mesh and preparation method thereof |
| CN109078497A (en) * | 2018-08-22 | 2018-12-25 | 长春盛恒环保科技有限公司 | A kind of purifying vehicle exhaust treatment fluid and preparation method thereof |
| CN111389208A (en) * | 2020-03-25 | 2020-07-10 | 山东骏逸环境科技有限公司 | Amino denitration agent and preparation method thereof |
| WO2021198579A1 (en) * | 2020-03-30 | 2021-10-07 | Totalenergies Marketing Services | Use of a composition for removing pollutants from exhaust gases produced by heat engines |
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| US20110030345A1 (en) * | 2008-09-09 | 2011-02-10 | Man Nutzfahrzeuge Aktiengesellschaft | Method for reducing nitric oxide in the exhaust gas flow of internal combustion engines |
| CN102213124A (en) * | 2011-05-24 | 2011-10-12 | 辽宁润迪精细化工有限公司 | Ultralow-temperature urea reducing agent composition |
| CN102213125A (en) * | 2011-05-24 | 2011-10-12 | 辽宁润迪精细化工有限公司 | Urea reducing agent composition with improved low-temperature performance |
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2015
- 2015-01-13 CN CN201510015958.2A patent/CN104675483A/en active Pending
Patent Citations (4)
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| CN1730601A (en) * | 2005-08-15 | 2006-02-08 | 杨毅男 | Multifunctional antifreeze vehicle cooling liquid |
| US20110030345A1 (en) * | 2008-09-09 | 2011-02-10 | Man Nutzfahrzeuge Aktiengesellschaft | Method for reducing nitric oxide in the exhaust gas flow of internal combustion engines |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105498537A (en) * | 2015-11-30 | 2016-04-20 | 许昌学院 | Low-temperature diesel exhaust reducing agent and preparation method thereof |
| CN107081066A (en) * | 2017-05-02 | 2017-08-22 | 盘锦鑫安源化学工业有限公司 | A kind of diesel motor exhaust scavenging solution of nodeless mesh and preparation method thereof |
| CN109078497A (en) * | 2018-08-22 | 2018-12-25 | 长春盛恒环保科技有限公司 | A kind of purifying vehicle exhaust treatment fluid and preparation method thereof |
| CN111389208A (en) * | 2020-03-25 | 2020-07-10 | 山东骏逸环境科技有限公司 | Amino denitration agent and preparation method thereof |
| WO2021198579A1 (en) * | 2020-03-30 | 2021-10-07 | Totalenergies Marketing Services | Use of a composition for removing pollutants from exhaust gases produced by heat engines |
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Application publication date: 20150603 |
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