CN1151431A - Method for reclaiming solvent in process of isopropyl alcohol urea - Google Patents
Method for reclaiming solvent in process of isopropyl alcohol urea Download PDFInfo
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- CN1151431A CN1151431A CN 95118393 CN95118393A CN1151431A CN 1151431 A CN1151431 A CN 1151431A CN 95118393 CN95118393 CN 95118393 CN 95118393 A CN95118393 A CN 95118393A CN 1151431 A CN1151431 A CN 1151431A
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Abstract
A solvent recovery process for dewaxing isopropanol urea features that a mixed solvent instead of water is used as solvent to wash the dewaxed products (dewaxed oil and wax liquid) of ispropanol urea and washing oil, the urea is washed out without changing other components in reaction resultant and washing oil, and the reaction resultant and washing oil are directly distilled to separate out product and washing oil and to recover isopropanol. Its advantages are no need of ternary azeotropic distillation procedure, low energy consumption and less discharged sewage.
Description
The present invention relates to the method for reclaiming solvent in process of isopropyl alcohol urea.
In petroleum refining industry,, often adopt the Virahol aqueous solution of urea to handle diesel oil distillate, the method that liquid wax is deviate from order to obtain liquid wax and low freezing point diesel fuel.This method is according to the stock oil wax content and to the requirement of purpose product, with stock oil and finite concentration, the Virahol aqueous solution of urea of some amount mixes mutually, in complex reactor, carry out complex reaction while cooling off, under the effect of Virahol activator, the wax in the stock oil (normal paraffin) forms the complex compound that is insoluble to oil and Virahol aqueous solution of urea with urea.Then oil (pressed oil) is told, again with the complex compound thermal degradation, wax liquid just separates with urea soln, and urea soln is reused.In this process, because attached a certain amount of oil is usually inhaled again on the complex compound surface, for the yield that improves pressed oil with obtain highly purified whiteruss, complex compound is before thermolysis, also to use lightweight oil (washing oil, 80-180 ℃ of distillate) wash, as Л. Г. С у ш к о, В. А. Л и б e р м а н, М. А. Г а л и м о в, В. А. К о к и н, С о в e р ш e н с т в о в а н и e с х e м ы р e г e н e р а ц и и к а р б а м и ц а и и э о п р о п и л о в о г о с п и р т а и э р а с т в о р о в р e а к ц и и в П р о ц e с с e к а р б а м и ц н о й ц e п а р а ф и н и э а ц и и. Н e х т e п e р e р а б о т к а и Н e х т e ф и м и я .1986, (10): 18 is described, through the reaction product of this process (pressed oil. wax liquid) and the washing complex compound after washing oil in, be dissolved with Virahol 6-20%, urea 0.1-0.8%.The fractions consisting of its meltage and product.Dewaxing temperature, the heat decomposition temperature of complex compound, the fractions consisting of washing oil is relevant.When reclaiming Virahol and washing oil, the urea in reaction product and the washing oil must be removed, otherwise when reclaiming Virahol and washing oil with distillation method, urea and degradation production thereof very easily stop up tower tray.Cause periodically ending dewaxing and produce, stop tower and clean.
The document is also spoken of, and for fear of stifled tower, on all Virahol urea dewaxing devices, all adopts water or contains Virahol water seldom, and is first the urea flush away from reaction product and washing oil, and then the distillatory technical process.
Also speak of among the SU1070149A in the Virahol urea dewaxing process, first water is washed the urea in reaction product and the washing lotion off, and then distills, and reclaims Virahol and washing oil and obtains the purpose product.After washing reaction product and washing oil with water, obtain urea-containing diluted alcohol aqueous solution, then, urea-containing diluted alcohol aqueous solution reclaims Virahol with distillating method, obtain containing the aqueous solution of Virahol 80-85%, if this part Virahol is recycled, just must be further that the azeotropic alcohol extracting is dense to＞96%, the Virahol aqueous solution of urea composition of dewaxing usefulness is remained unchanged.
Above-mentioned document and patent are all spoken of in the Virahol urea dewaxing process, and the urea that first water (or containing a small amount of Virahol) is washed off in reaction product and the washing lotion also washes wherein Virahol come.When reclaiming Virahol from diluted alcohol aqueous solution, Virahol and water form azeotrope, only can obtain the Virahol that concentration is 80-85%.Could reuse after dense so need further carry by ternary azeotropic distillation.So not only increase energy consumption, and increase the consumption of chemical, also make technological process and equipment become complicated, must discharge a large amount of sewage simultaneously.
The objective of the invention is to overcome Virahol urea dewaxing solvent recuperation energy consumption, chemical cost is big, and technological process and equipment complexity, the shortcoming that must discharge a large amount of sewage simultaneously adopts mixed solvent washing reaction product and washing oil.
The present invention adopts the cleaning solvent of mixed solvent as reaction product and washing oil, washing reaction product (pressed oil, wax liquid) and washing oil, this mixed solvent compositing range is: oily 0-25w%, Virahol 25-75w%, water 5-75w%, wherein said oil can be pressed oil, wax liquid or washing oil, selects according to the principle consistent with the washings component.
For different washings, can form the preparation mixed solvent by table-1.
The mixed solvent of table-1 washing differential responses product is formed (w%)
Solvent-1 in the table-1: be used to wash the mixed solvent of pressed oil,
| Oil | Virahol | Water | |
| Solvent-1 | ????0-10 | ????60-75 | ????15-40 |
| Solvent-2 | ????0-25 | ????45-75 | ????10-55 |
| Solvent-3 | ????0-15 | ????25-65 | ????20-75 |
Solvent-2: be used to wash the mixed solvent of wax liquid,
Solvent-3: be used to wash the mixed solvent of washing oil,
(" oil " refers to pressed oil, wax liquid and washing oil respectively in the table, and is as follows)
Wash conditions:
Reaction product with mix washing lotion ratio: 1-30: 1
Wash temperature: 30-70 ℃
Stirring velocity: 200-300 rev/min
Washing time: 5-10 minute
Time of repose: 5-10 minute
With mixed solvent washing reaction product and washing oil, only the urea in reaction product and the washing lotion is washed off, and other compositions are constant.Urea content＜40ppm in reaction product after washing and the washing oil, but direct heating distills, when obtaining purpose product and washing oil, also obtained the isopropanol water solution that can directly recycle (isopropyl alcohol concentration taken out of of its concentration and reaction product or washing oil quite or slightly high).
Urea content is 1-6w% (concentration of urea is close during with present full scale plant sewage effluent) in the mixed solvent behind washing reaction product and the washing oil.With the distillatory method this mixed solvent is regenerated, tell urea.Mixed solvent after regeneration is reusable.
Example 1
The reaction product of experiment usefulness is that the dewaxing of the isopropanol and urea aqueous solution obtains.Raw material is a grand celebration 220-310 ℃ fraction, and washing oil is a grand celebration 120-160 ℃ fraction.See Table-2 with reaction product after the washing oil washing and washing oil composition.
The composition (w%) of table-2 reaction product and washing oil
| Oil | Virahol | Water | Urea | |
| Pressed oil | ????96.58 | ????3.30 | ????0.10 | ????0.02 |
| Wax liquid | ????95.20 | ????4.56 | ????0.20 | ????0.04 |
| Washing oil | ????96.20 | ????3.55 | ????0.20 | ????0.05 |
The mixed solvent preparation
Get a certain amount of Virahol and be dissolved in the water, make its solution that becomes homogeneous transparent, the mixed solvent composition sees Table-3,
Table-3 mixed solvents are formed (w%)
| Oil | Virahol | Water | |
| Solvent-1 | ????0.00 | ????60.90 | ????39.10 |
| Solvent-2 | ????0.00 | ????49.64 | ????50.16 |
| Solvent-3 | ????0.00 | ????28.80 | ????71.20 |
Table-4 wash conditions
| Dewaxing liquid | Wax liquid | Washing oil | |
| The finish ratio | ????30∶1 | ????30∶1 | ????30∶1 |
| Wash temperature ℃ | ????50 | ????65 | ????40 |
| The churning time branch | ????8 | ????5 | ????10 |
| The time of repose branch | ????8 | ????5 | ????10 |
By the wash conditions of table in-4, reaction product or washing oil and mixed solvent are added in the washer simultaneously, at the uniform velocity stir and made its thorough mixing 5-10 minute, left standstill then 5-10 minute, the two-phase that will be divided into is sampling analysis respectively.Analytical results is in table-5 and table-6.
The afterreaction product washed by table-5 and washing oil is formed (w%)
| Oil | Virahol | Water | Urea | |
| Pressed oil | ????96.55 | ????3.35 | ????0.10 | ????24.6ppm |
| Wax liquid | ????95.23 | ????4.57 | ????0.20 | ????23.2ppm |
| Washing oil | ????96.34 | ????3.57 | ????0.19 | ????21.7ppm |
Table-6 washing back mixed solvents are formed (w%)
| Oil | Virahol | Water | Urea | |
| Solvent-1 | ????0.00 | ????60.60 | ????38.81 | ????0.60 |
| Solvent-2 | ????0.00 | ????48.96 | ????49.85 | ????1.19 |
| Solvent-3 | ????0.00 | ????28.41 | ????70.11 | ????1.48 |
Data are found out from table-5, and reaction product and washing oil are after the mixed solvent washing, and urea is removed substantially, and 20-30ppm is only arranged, and distillation is not had influence, and other components do not change substantially.Containing urea mixed solvent regeneration back reuses.
Mixed solvent regeneration embodiment
This is treated that the regenerative mixed solvent distills under 90-100 ℃ of condition, the azeotrope that its Virahol and water form 80-82% distillates, and is aqueous solution of urea in the still, can enter Sewage treatment systems.Distillation the results are shown in table-7.
The distillation result (w%) of table-7 regenerative mixed solvents
| Overhead product | Thing in the still | Distillation loss | |||
| Virahol | Water | Water | Urea | ||
| Wash-1 | ????59.30 | ????13.91 | ????23.63 | ????0.60 | ????2.56 |
| Wash-2 | ????47.61 | ????11.52 | ????37.54 | ????1.19 | ????2.14 |
| Wash-3 | ????27.89 | ????6.55 | ????63.45 | ????1.48 | ????1.57 |
Form preparation new mixed solvent washing reaction product and washing oil with the Virahol that reclaims by mixed solvent in the table-3.
Embodiment 2
Reaction product and washing oil are formed as table-8
Table-8 reaction product and washing oil are formed (w%)
The preparation of mixed solvent is with example 1, and it is formed as table-9.
| Oil | Virahol | Water | Urea | |
| Pressed oil | ??92.41 | ???7.24 | ????0.30 | ????0.05 |
| Wax liquid | ??79.85 | ???18.99 | ????0.98 | ????0.18 |
| Washing oil | ??80.43 | ???17.64 | ????1.58 | ????0.35 |
Table-9 mixed solvents are formed (w%)
Wash conditions: finish is than pressed oil 20: 1, wax liquid 10: 1, washing oil 10: 1
| Oil | Virahol | Water | Urea | |
| Solvent-1 | ????4.34 | ????74.76 | ????20.90 | ????0.00 |
| Solvent-2 | ????11.15 | ????71.78 | ????17.07 | ????0.00 |
| Solvent-3 | ????23.19 | ????67.28 | ????9.52 | ????0.00 |
Other condition and example-1 together.
The afterreaction product washed by table-10 and washing oil is formed (w%)
| Oil | Virahol | Water | Urea | |
| Pressed oil | ????92.44 | ????7.26 | ????0.30 | ??26.0ppm |
| Wax liquid | ????79.98 | ????19.03 | ????0.98 | ??29.1ppm |
| Washing oil | ????80.69 | ????17.72 | ????1.59 | ??37.6ppm |
Table-11 is washed the back mixed solvent and is formed (w%)
Mixed solvent regeneration is washed the back mixed solvent and is regenerated with distillating method, and the distillation result is as table-12
| Oil | Virahol | Water | Urea | |
| Solvent-1 | ????4.32 | ????74.00 | ????20.69 | ????1.00 |
| Solvent-2 | ????10.97 | ????70.50 | ????16.77 | ????1.77 |
| Solvent-3 | ????7.15 | ????61.16 | ????28.31 | ????3.38 |
The distillation result (w%) of table-12 regenerative mixed solvents
| Overhead product | Thing in the still | Distillation loss | ||||
| Virahol | Water | Oil | Water | Urea | ||
| Wash-1 | ????72.47 | ????16.79 | ????4.52 | ????3.33 | ????1.00 | ??1.89 |
| Wash-2 | ????69.40 | ????15.28 | ????10.97 | ????1.25 | ????1.77 | ??1.33 |
| Wash-3 | ????59.89 | ????14.51 | ????7.15 | ????13.49 | ????3.38 | ??1.58 |
Embodiment 3
Reaction product and washing oil are formed as table 13
Table-13 reaction product and washing oil are formed (w%)
| Oil | Virahol | Water | Urea | |
| Pressed oil | ??87.03 | ??12.41 | ??0.48 | ????0.08 |
| Wax liquid | ??66.53 | ??30.77 | ??2.29 | ????0.41 |
| Washing oil | ??72.15 | ??25.48 | ??1.90 | ????0.47 |
The preparation of mixed dissolution.
The compound method of mixed dissolution is with example 1, and it is formed as table 14.
Table-14 mixed solvents are formed (w%)
Wash conditions: finish is than pressed oil 20: 1, wax liquid 2.5: 1, washing oil 5: 1
| Oil | Virahol | Water | Urea | |
| Solvent-1 | ????9.67 | ????73.25 | ????17.08 | ????0.00 |
| Solvent-2 | ????23.20 | ????67.35 | ????9.45 | ????0.00 |
| Solvent-3 | ????14.36 | ????62.54 | ????23.10 | ????0.00 |
Other condition same example-1.
Washing afterreaction product and washing oil forms as table 15.
The afterreaction product washed by table-15 and washing oil is formed (w%)
| Oil | Virahol | Water | Urea | |
| Pressed oil | ????87.09 | ????12.43 | ????0.48 | ????28.6ppm |
| Wax liquid | ????66.78 | ????30.92 | ????2.30 | ????32.0ppm |
| Washing oil | ????72.49 | ????25.60 | ????1.91 | ????38.6ppm |
Washing the back mixed solvent forms as table 16.
Table-16 is washed the back mixed solvent and is formed (w%)
| Oil | Virahol | Water | Urea | |
| Solvent-1 | ????9.57 | ????72.07 | ????16.79 | ????1.57 |
| Solvent-2 | ????23.01 | ????66.58 | ????9.40 | ????1.01 |
| Solvent-3 | ????14.13 | ????61.01 | ????22.56 | ????2.30 |
The regeneration of mixed solvent
The distillation result such as the table 17 of regenerative mixed solvent.
The distillation result (w%) of table-17 regenerative mixed solvents
| Overhead product | Thing in the still | Distillation loss | ||||
| Virahol | Water | Oil | Water | Urea | ||
| Wash-1 | ????70.43 | ????15.67 | ??9.57 | ????0.95 | ????1.57 | ??1.81 |
| Wash-2 | ????64.74 | ????9.25 | ??23.00 | ????0.00 | ????1.01 | ??2.00 |
| Wash-3 | ????59.37 | ????14.03 | ??14.13 | ????8.21 | ????2.30 | ??1.96 |
From the table 5,10 of above-mentioned example, 15 data as can be seen, reaction product and washing oil are after the mixed solvent washing, and urea content＜40ppm does not have influence to distillation, and other component is constant substantially.
Urea-containing mixed solvent can be regenerated by distillation, and Virahol distillates with the 80-82% aqueous solution, and residue is divided into two-phase in the still, and oil phase can be used as the raw material of product or preparation mixed solvent, and water (containing urea) advances sink drainage to be handled.
Find out that from table 12,17 data in the mixed solvent regenerative process, with the sewage of containing urea that produces about 10%, to handle 60,000 tons of raw materials year, annual blowdown 400-800 ton only is the 20-40% of present full scale plant.
Wherein the sewage quantity of required discharging is big slightly among the embodiment 1, is because " oil " content is 0 in the used mixed solvent, is a kind of special case, if hope reduces blowdown then should not adopt.
Replace washing process with method of the present invention, can significantly reduce binary distillation amount, save the ternary azeotropic distillation.
Claims (4)
1. method that is used for isopropanol and urea dewaxing process solvent recuperation, it is characterized in that with the reaction product of mixed solvent washing Virahol urea dewaxing process and the urea in the washing oil, reaction product and washing oil straight run distillation are isolated product and washing oil then, and recovery Virahol, said mixed solvent consists of, oily 0-25w%, Virahol 25-75w%, water 5-75w%, being washed material and mixed solvent weight ratio is 1-30: 1.
2. according to the method for claim 1, it is characterized in that washing the used mixed solvent of dewaxing liquid and consist of, pressed oil 0-10w%, Virahol 60-75w%, water 15-40w%.
3. according to the method for claim 1, it is characterized in that washing the used mixed solvent of wax liquid and consist of, wax liquid 0-25w%, Virahol 45-75w%, water 10-55w%.
4. according to the method for claim 1, it is characterized in that washing the used mixed solvent of washing oil and consist of, pure washing oil 0-15w%, Virahol 25-65w%, water 20-75w%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95118393A CN1055962C (en) | 1995-11-30 | 1995-11-30 | Method for reclaiming solvent in process of isopropyl alcohol urea |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95118393A CN1055962C (en) | 1995-11-30 | 1995-11-30 | Method for reclaiming solvent in process of isopropyl alcohol urea |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1151431A true CN1151431A (en) | 1997-06-11 |
| CN1055962C CN1055962C (en) | 2000-08-30 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN95118393A Expired - Fee Related CN1055962C (en) | 1995-11-30 | 1995-11-30 | Method for reclaiming solvent in process of isopropyl alcohol urea |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104560195A (en) * | 2013-10-24 | 2015-04-29 | 中国石油化工股份有限公司 | Dewaxing method of isopropanol urea |
| CN105733677A (en) * | 2014-12-06 | 2016-07-06 | 中国石油化工股份有限公司 | Solvent recovery method for isopropanol urea dewaxing process |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2517310C3 (en) * | 1975-04-18 | 1981-10-15 | Deutsche Texaco Ag, 2000 Hamburg | Process for the regeneration of aqueous urea solutions |
| AT351135B (en) * | 1977-06-08 | 1979-07-10 | Oemv Ag | METHOD AND DEVICE FOR PURIFYING UREA SOLUTIONS |
| SU1070149A1 (en) * | 1979-06-06 | 1984-01-30 | Ордена Трудового Красного Знамени Институт Нефтехимических Процессов Им.Акад.Ю.Г.Мамедалиева | Process for deparaffination of distillate petroleum products |
| SU952950A1 (en) * | 1979-07-02 | 1982-08-23 | Ордена Трудового Красного Знамени Институт Нефтехимических Процессов Им.Акад.Ю.Г.Мамедалиева | Process for deparaffination of petroleum products |
-
1995
- 1995-11-30 CN CN95118393A patent/CN1055962C/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104560195A (en) * | 2013-10-24 | 2015-04-29 | 中国石油化工股份有限公司 | Dewaxing method of isopropanol urea |
| CN104560195B (en) * | 2013-10-24 | 2016-02-10 | 中国石油化工股份有限公司 | A kind of Virahol urea dewaxing method |
| CN105733677A (en) * | 2014-12-06 | 2016-07-06 | 中国石油化工股份有限公司 | Solvent recovery method for isopropanol urea dewaxing process |
| CN105733677B (en) * | 2014-12-06 | 2017-03-22 | 中国石油化工股份有限公司 | Solvent recovery method for isopropanol urea dewaxing process |
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| CN1055962C (en) | 2000-08-30 |
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