CN107417577A - The method and device of biuret is removed in urea for vehicle - Google Patents
The method and device of biuret is removed in urea for vehicle Download PDFInfo
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- CN107417577A CN107417577A CN201610346678.4A CN201610346678A CN107417577A CN 107417577 A CN107417577 A CN 107417577A CN 201610346678 A CN201610346678 A CN 201610346678A CN 107417577 A CN107417577 A CN 107417577A
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- urea
- filter
- biuret
- exchange resin
- container
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
- C07C273/14—Separation; Purification; Stabilisation; Use of additives
- C07C273/16—Separation; Purification
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- Treatment Of Liquids With Adsorbents In General (AREA)
Abstract
The invention discloses the method and device that biuret is removed in a kind of urea for vehicle, belong to the preparing technical field of urea for vehicle, methods described comprises the following steps：Weight of urea percentage is prepared as 31.8% 33.2% urea liquid；Obtained urea liquid cools to there is gonorrhoea state；The urea liquid filtering of gonorrhoea state is will appear from, until urea liquid is clarified；The mass percent for obtaining biuret is less than 0.3% urea for vehicle solution.Described device includes accommodating the container of urea liquid, the inside of the container is provided with agitating device, the container is sequentially communicated first filter and the second filter by pipeline, pipeline between the container and the first filter is provided with the first delivery pump, and the pipeline between the container and second filter is provided with the second delivery pump.Compared to the prior art, the present invention has method simple, removes the advantages of biuret effect is good.
Description
Technical field
The present invention relates to the preparing technical field of urea for vehicle, biuret is removed in specifically a kind of urea for vehicle
Method and device.
Urea water plays the role of that Nox can be purified, and is widely used in the gas-purification system of large-scale diesel vehicle.Automobile
Urea, it be a kind of use in SCR technology, for reducing the liquid of the nitrogen oxides pollution in exhaust gas from diesel vehicle.Automobile-used urine
Plain scientific name is diesel engine vent gas treatment fluid, and the country is commonly called as automobile urea, urea for vehicle, automobile environment-protection urea, automobile-used denitrfying agent, made
With it is most common be urea for vehicle.Urea for vehicle is used for reduction of nitrogen oxide, can be used as SCR (Selective Catalytic
Reduction, SCR) system reducing agent, utilize the bavin such as the urea for vehicle aqueous solution and heavy truck, car
Reaction of nitrogen oxides generation N in oily tail gas2And H2O carrys out cleaning of off-gas, its nitrogen oxides discharged is reached Europe IV discharges
Standard.
Urea is in granulation process, and when temperature is more than 133 DEG C, condensation reaction will occur for urea, produces biuret, urine
Plain water easily remains biuret in preparation process；Biuret can not separate out under normal temperature condition.Meanwhile the purity of urea for vehicle will
Very high, common urea or urine is asked to can not meet requirement of the urea for vehicle to high-purity, the urea for vehicle product of in the market
The problem of biuret that quality is extremely difficult in international standard, particularly urea for vehicle is exceeded, how to reduce in urea for vehicle and contract
The content of two ureas turns into a serious problems for restricting urea for vehicle industry development.
At present, the method for reducing Biuret Content in urea product typically used is for recrystallization method and in evaporation process
The formation of biuret is prevented, however, recrystallization method yield is low, cost is high；The effect of the formation of biuret is prevented in evaporation process
Fruit is extremely limited.The method that also can reduce the content of biuret in urea for vehicle in positive exploration in the industry, such as such as
Lower patent：
Chinese patent（CN 104289106 A）Disclose a kind of preparation method of urea for vehicle solution, its use it is not concentrated,
Ammonia and CO be granulated and that remnants are removed through flash distillation2Afterwards, high-temperature high concentration urea solution is raw material, is used directly to produce automobile-used urine
Plain solution.The method provided in the patent limits the finished product urea for vehicle produced by using the raw material of low Biuret Content
In Biuret Content, although this method step is relatively simple, the production cost of its raw material is very high, the urea raw material into
This is the several times of common urea, causes the production cost of urea for vehicle very high.
Chinese patent（CN 104402769 A）A kind of production technology of urea for vehicle is disclosed, by production technology
Adjust to reduce the content of biuret in urea for vehicle product, still, the method for the patent operates sufficiently complex, required equipment
Also it is more complicated, cause operability and production efficiency ratio relatively low.
In addition, the above method reduces biuret in urea for vehicle by changing the preparation technology of overall urea for vehicle
Content, not individually remove urea for vehicle in biuret method.
The content of the invention
In view of the above-mentioned problems, it is an object of the invention to provide the method and dress that biuret is removed in a kind of urea for vehicle
Put, this method strong operability and removal effect is good, common urea can be used to be substantially reduced automobile-used as raw material production urea for vehicle
The production cost of urea；The apparatus structure is simple, for removing the biuret in urea for vehicle.
The present invention, which solves the technical scheme that its technical problem is taken, to be included：The method that biuret is removed in urea for vehicle,
Comprise the following steps：
Step 1）：Prepare the urea liquid that weight of urea percentage is 32.5%-65%；
Step 2）：By step 1）In obtained urea liquid cool to there is gonorrhoea state；
Step 3）：By step 2）The middle urea liquid filtering for gonorrhoea state occur, until urea liquid is clarified；
Step 4）：The mass percent for obtaining biuret is less than 0.3% urea for vehicle solution.
Further technical scheme is：The step 1）Concrete operation method be urea to be put into deionized water, to going
Ionized water is heated and is stirred simultaneously, until urea is completely dissolved, forms urea liquid.
To reach the best precipitation effect of biuret, further technical scheme is：The step 2）In, by urea liquid
Cool to -5~17 DEG C.
For the filter effect reached, further technical scheme is：The step 3）In, urea liquid passes through two successively
Level filtering, the filtering accuracy of first order filtering is 25 μm, and the filtering accuracy of second level filtering is 1 μm；Urine is kept in filter process
The temperature of plain solution is constant, that is, keeps urea liquid in low-temperature condition.
Further technical scheme is：The first order filters and second level filtering uses ion exchange resin filter core.
From the point of view of filter effect, preferable technical scheme is：The ion exchange resin filter core is handed over for anion
Change resin filter element.
Consider from economy and filter effect comprehensive angle, selectable technical scheme is：The ion exchange resin filter
The filter core that core is anion exchange resin and cationic ion-exchange resin combination is formed, the wherein amount of anion exchange resin are more than sun
The amount of ion exchange resin.
Further technical scheme is：The urea liquid flows through first order filtering and flows through the flow velocity of second level filtering not
Together.Generally, the flow velocity that liquid stream filters through the first order is more than the flow velocity for flowing through second level filtering, filters step by step with maximum limit
The biuret removed in urea liquid of degree.
The scheme that the present invention solves its technical problem also includes：The device of the above method is realized, including accommodates urea liquid
Container, the inside of the container is provided with agitating device, and the container is sequentially communicated first filter and the second mistake by pipeline
Filter, the pipeline between the container and the first filter are provided with the first delivery pump, the first filter with it is described
Pipeline between second filter is provided with the second delivery pump；It is temporary that solution is provided between the first filter and the second delivery pump
Pond is deposited, the first filter and the second delivery pump are connected with the solution scratch pool.
Solution scratch pool is set, passes through the second delivery pump, thus it is possible to vary into the flow velocity of the solution of the second filter, is realized
The flow velocity of double-filtration is different.
For ease of heating and cooling to solution, further technical scheme is：The bottom of the container is provided with heater,
The side wall of the container is provided with cooling tube.
The beneficial effects of the invention are as follows：
1st, by the research of solubility and the relation of temperature to biuret, it is found that biuret solubility in low temperature can become
Change, so as to realize the biuret removed by way of filtering in urea liquid, can substantially reduce in urea for vehicle product
The content of biuret, method is simple, removal effect is good, solve tradition remove biuret recrystallization method yield is low, cost is high
The problem of, so as to which realization produces urea for vehicle solution by the use of common urea as raw material, substantially reduce the production cost of urea for vehicle；
2nd, research is found, biuret separates out from urea liquid under low-temperature condition, makes urea liquid that gonorrhoea state be presented, precipitation
Biuret ion is powered, therefore, using ion exchange resin as filter core, substantially increases filter effect and the effect filtered
Rate.
3rd, the present apparatus is used to remove the biuret in urea liquid, and stirring and filtering are integrated in be formed on a device and flowed
Ability of swimming operation, simple in construction, easy to operate, production efficiency is high.
4th, in device of the invention, contain and heater and cooler device is carried in the container of solution, be easy to solution in container
Temperature be controlled, further improve operating efficiency；Dress centers liquid scratch pool, passes through the second delivery pump, thus it is possible to vary
Into the flow velocity of the solution of the second filter, realize that the flow velocity of double-filtration is different, improve filter effect.
Brief description of the drawings
Fig. 1 is the structural representation of device of the embodiment of the present invention；
Fig. 2 is the curve map of biuret solubility and temperature relation.
In figure：1 solution tank, 2 stirring vanes, 3 heating tubes, 4 first delivery pumps, 5 first filters, 6 second delivery pumps, 7
Second filter, 8 solution scratch pools.
Embodiment
With reference to Figure of description and specific embodiment, the invention will be further described：
Embodiment one：
The method that biuret is removed in urea for vehicle, it comprises the following steps：
Step 1）：Solid urea particle and purified water are inserted in solution tank, stirs to being completely dissolved, weight of urea percentage is made
Than the urea liquid for 32.5%；
Step 2）：Step 1）The process of middle solid urea particle dissolving is exothermic process, and obtained urea liquid is in low temperature shape
State, by step 1）In obtained urea solution temperature be down to -5 DEG C, now gonorrhoea state is presented in urea liquid；
Step 3）：Will appear from the urea liquid of gonorrhoea, to pass sequentially through filtering accuracy by pipeline pump be 25 μ first filters and mistake
Filter precision is 1 the second filters of μ；
First filter inner filter core is anion exchange resin；Second filter element is that weight ratio is 8：2 anion exchange
Resin and cationic ion-exchange resin；
The flow that urea liquid passes through first filter is 25L/min；The flow that urea liquid passes through the second filter is 15L/
min.During urea liquid is by first filter and the second filter, the temperature of urea liquid maintains -10 all the time
℃。
Step 4）：Obtain the urea liquid of Biuret Content 0.25%.
Embodiment two：
The method that biuret is removed in urea for vehicle, it comprises the following steps：
Step 1）：Solid urea particle and purified water are inserted in solution tank, to solid urea particle and the mixture of purified water
Heated, the urea liquid for being completely dissolved, being made that weight of urea percentage is 45% is stirred while heating；
Step 2）：By step 1）In obtained urea solution temperature be down to 0 DEG C, now gonorrhoea state is presented in urea liquid；
Step 3）：Will appear from the urea liquid of gonorrhoea, to pass sequentially through filtering accuracy by pipeline pump be 25 μ first filters and mistake
Filter precision is 1 the second filters of μ；
First filter inner filter core is that weight ratio is 9：1 anion exchange resin and cationic ion-exchange resin；Second filter
Filter core is that weight ratio is 7：3 anion exchange resin and cationic ion-exchange resin；
The flow that urea liquid passes through first filter is 25L/min；The flow that urea liquid passes through the second filter is 15L/
min.During urea liquid is by first filter and the second filter, the temperature of urea liquid maintains 0 DEG C all the time.
Step 4）：Obtain the urea liquid of Biuret Content 0.27%.
Embodiment three：
The method that biuret is removed in urea for vehicle, it comprises the following steps：
Step 1）：Solid urea particle and purified water are inserted in solution tank, stirs to being completely dissolved, weight of urea percentage is made
Than the urea liquid for 60%；
Step 2）：Step 1）The process of middle solid urea particle dissolving is exothermic process, and obtained urea liquid is in low temperature shape
State, by step 1）In obtained urea solution temperature be down to 8 DEG C, now gonorrhoea state is presented in urea liquid；
Step 3）：Will appear from the urea liquid of gonorrhoea, to pass sequentially through filtering accuracy by pipeline pump be 25 μ first filters and mistake
Filter precision is 1 the second filters of μ；
First filter inner filter core is that weight ratio is 9：1 anion exchange resin and cationic ion-exchange resin；Second filter
Filter core is anion exchange resin；
The flow that urea liquid passes through first filter is 20L/min；The flow that urea liquid passes through the second filter is 12L/
min.During urea liquid is by first filter and the second filter, the temperature of urea liquid maintains -5 all the time
℃。
Step 4）Obtain the urea liquid of Biuret Content 0.24%.
The relation of solubility and temperature of the biuret in water is as shown in Fig. 2 with the reduction of temperature, the dissolving of biuret
Degree drastically declines, and when temperature is below 17 DEG C, biuret almost separates out and maintains plateau completely, from cost consideration ,-
5~17 DEG C of temperature range is the most suitable, but when temperature is lower, has no effect on precipitation and filter effect, therefore, may be alternatively provided as
Lower temperature.
In the method for the present invention, the series of filtering is not limited to double-filtration, can increase the series of filtering, by continuously carrying
The pure amount for further reducing biuret, increase the transparency of solution, lift the quality of solution.In addition, improve the dense of urea liquid
Degree can make adsorption effect more preferably.
As shown in figure 1, realizing the device of the above method, including the solution tank 1 of urea liquid is accommodated, the solution tank 1
Bottom is provided with stirring vane 2, and the solution tank 1 is sequentially communicated the filter 7 of first filter 5 and second by pipeline, described molten
Pipeline between liquid bucket 1 and the first filter 5 is provided with the first delivery pump 4, the solution tank 1 and second filter
Pipeline between 7 is provided with the second delivery pump 6.
Solution scratch pool 8, the first filter 5 and second are provided between the delivery pump 6 of first filter 5 and second
Delivery pump 6 is connected with the solution scratch pool 8.Solution scratch pool 8 is set, passes through the second delivery pump 6, thus it is possible to vary is entered
The flow velocity of the solution of second filter 7, realize that the flow velocity of double-filtration is different.Generally, the first filtering should be allowed fluid flow through
The flow velocity of device 5 is more than the flow velocity for flowing through the second filter 7, sets multistage filtering to remove the contracting in urea liquid to greatest extent
Two ureas.
Heating tube 3 is provided with the bottom of solution tank 1, the side wall of the solution tank 1 is provided with cooling tube（Not shown in figure）.
In order to realize the heating and cooling of solution in solution tank 1, heating tube 3 carries out heating to solution can accelerate solid urea particle
Dissolution velocity, cooling tube can quickly cool, and urea liquid is quickly down to required temperature, improve operating efficiency.Molten
Temperature sensor can be set in liquid bucket 1, using the detection signal of temperature sensor as signal source, to realize heating tube 3 and cooling tube
The operating circuit of automatic work, heating tube 3 and cooling tube can be switched over by switching relay, or be entered by magnetic valve
Row circuit is connected or disconnected, and automaticity is high, and the accuracy of control is improved while saving manpower.Relay switching electricity
Road is the conventional control circuit of this area, and magnetic valve is also common component, to those skilled in the art, completely can root
The setting to said elements is completed according to prior art, its specific method to set up will not be repeated here.
In the present invention, filter is not limited to set the two-stage described in embodiment, can increase the quantity of filter,
Continuous purification is realized, in order to ensure filter effect, filter should at least set two-stage.
In the present invention, the ratio of anion exchange resin and cationic ion-exchange resin in filter is not limited to embodiment
Disclosed in ratio, both ratios can be made a change because anion exchange resin to biuret ion absorption effect
Fruit is more preferable, and to ensure filter effect, the amount of anion exchange resin should be greater than the amount of cationic ion-exchange resin, or all use
Anion exchange resin.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not the whole embodiments of the present invention, not limiting
The system present invention, within the spirit and principles of the invention, any modification, equivalent substitution and improvements made etc., should be included in
Within protection scope of the present invention.
In addition to technical characteristic described in specification, remaining technical characteristic is technology known to those skilled in the art, in order to prominent
Go out the innovative characteristicses of the present invention, above-mentioned technical characteristic will not be repeated here.
Claims (10)
1. the method for biuret is removed in urea for vehicle, it is characterized in that, comprise the following steps：
Step 1）：Prepare the urea liquid that weight of urea percentage is 32.5%-65%；
Step 2）：By step 1）In obtained urea liquid cool to there is gonorrhoea state；
Step 3）：By step 2）The middle urea liquid filtering for gonorrhoea state occur, until urea liquid is clarified；
Step 4）：The mass percent for obtaining biuret is less than 0.3% urea for vehicle solution.
2. the method for biuret is removed in urea for vehicle according to claim 1, it is characterized in that, the step 1）It is specific
Operating method is that urea is put into deionized water, and deionized water is heated and is stirred simultaneously, until urea is completely molten
Solution, form urea liquid.
3. the method for biuret is removed in urea for vehicle according to claim 1, it is characterized in that, the step 2）In, will
Urea liquid cools to -5~17 DEG C.
4. the method for biuret is removed in urea for vehicle according to claim 1, it is characterized in that, the step 3）In, urine
Plain solution passes through double-filtration successively, and the filtering accuracy of first order filtering is 25 μm, and the filtering accuracy of second level filtering is 1 μm；
Keep the urea solution temperature constant in filter process.
5. the method for biuret is removed in urea for vehicle according to claim 4, it is characterized in that, first order filtering and second
Level filtering uses ion exchange resin filter core.
6. the method for biuret is removed in urea for vehicle according to claim 5, it is characterized in that, the ion exchange resin
Filter core is anion exchange resin filter core.
7. the method for biuret is removed in urea for vehicle according to claim 5, it is characterized in that, the ion exchange resin
The filter core that filter core is anion exchange resin and cationic ion-exchange resin combination is formed, the amount of wherein anion exchange resin are more than
The amount of cationic ion-exchange resin.
8. the method for biuret is removed in urea for vehicle according to claim 4, it is characterized in that, the urea liquid flows through
First order filtering is different with the flow velocity for flowing through second level filtering.
9. the device of the method described in claim 1 is realized, it is characterized in that, including accommodate the container of urea liquid, the container
Inside be provided with agitating device, the container is sequentially communicated first filter and the second filter by pipeline, the container with
Pipeline between the first filter is provided with the first delivery pump, between the first filter and second filter
Pipeline is provided with the second delivery pump；Solution scratch pool, first mistake are provided between the first filter and the second delivery pump
Filter and the second delivery pump are connected with the solution scratch pool.
10. device according to claim 9, it is characterized in that, the bottom of the container is provided with heater, the container
Side wall is provided with cooling tube.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201610346678.4A CN107417577A (en) | 2016-05-24 | 2016-05-24 | The method and device of biuret is removed in urea for vehicle |
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| CN201610346678.4A CN107417577A (en) | 2016-05-24 | 2016-05-24 | The method and device of biuret is removed in urea for vehicle |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108715466A (en) * | 2018-07-12 | 2018-10-30 | 四川凯源凡创环保科技有限公司 | Urea liquid blowdown recover |
| US20190091604A1 (en) * | 2017-09-22 | 2019-03-28 | Tenneco Automotive Operating Company Inc. | Method And Apparatus For Preparation Of A Urea Solution |
| WO2019195214A1 (en) * | 2018-04-04 | 2019-10-10 | Tenneco Automotive Operating Company Inc. | Method and apparatus for preparation of a urea solution |
| CN115400493A (en) * | 2022-09-13 | 2022-11-29 | 江苏可兰素环保科技有限公司 | Purification process of urea solution for vehicle |
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Application publication date: 20171201 |