CN102827202B - Technology for preparing diethyl phosphite by by-product of triethyl phosphite - Google Patents
Technology for preparing diethyl phosphite by by-product of triethyl phosphite Download PDFInfo
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- CN102827202B CN102827202B CN201210346251.6A CN201210346251A CN102827202B CN 102827202 B CN102827202 B CN 102827202B CN 201210346251 A CN201210346251 A CN 201210346251A CN 102827202 B CN102827202 B CN 102827202B
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- phosphite
- diethyl phosphite
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- phosphorous acid
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Abstract
The invention relates to a technology for preparing diethyl phosphite by by-product of triethyl phosphite, belonging to the field of a preparation technology of diethyl phosphite. The method utilizes the by-product generated in the production of the triethyl phosphite to react with phosphorous acid, and the diethyl phosphite in the by-product of the triethyl phosphite can be recycled; the product is high in yield and good in purity, the equipment investment is less and the production cost is low; and the technology has the characteristics of being less in emission load of waste gas and waste water, environment-friendly and the like. According to the technology, the whole production process can be completed by one set of acid mixing kettle, one set of synthesis kettle and one set of rectifying tower, so that a production device is simple, the production capacity is high, the equipment investment is less, the operation is simple, and the production efficiency is high. The technology is low in consumption and high in yield. The distillate on the top of the tower and the high boiling point material discharged from the bottom of the tower can be recycled in the acid mixing kettle, so that air pollution and waste water are not generated in the whole production process, and the sewage treatment cost is very low. The technology solves the problems that the existing triethyl phosphite production technology is complicated, low in product yield, higher in energy consumption and higher in production cost.
Description
Technical field
The present invention relates to a kind of technique that adopts triethyl-phosphite by product to produce diethyl phosphite, belong to diethyl phosphite preparation technique field.
Background technology
Present domestic triethyl-phosphite turnout has reached 20000 tons/year, diethyl phosphite is as the by product of triethyl-phosphite, its Main Components is 60～70% triethyl-phosphite, 20～30% diethyl phosphite and 8～10% ethanol, because of the boiling point of triethyl-phosphite and diethyl phosphite more approaching, its boiling point is respectively 156.5 DEG C and 187 DEG C, it is more difficult to separate with tower because boiling point is close, therefore old technique cannot reclaim triethyl-phosphite and diethyl phosphite wherein, the by product of approximately 500 tons/year of triethyl-phosphites is as pending biochemical treatments such as wastes according to statistics, bring certain impact to surrounding enviroment.
And diethyl phosphite has very consequence in fine chemistry industry, it can be made into composite flame-retardant agent, can be used as intermediate and produces fosetylaluminium, can produce organic phosphates desinsection, kills You agent and meet phosphonic acid ester and the phosphoric acid ester of various special requirements; Can also make the metal inhibitor for coating.
Although the synthetic method of diethyl phosphite is a lot, is summed up and mainly contains following two kinds:
1, prepared by phosphorous acid and alcohol direct esterification; But this method speed of response is subject to the restriction of factors, product yield is not high, therefore its development is restricted, not yet realizes so far suitability for industrialized production.
2, adopt phosphorus trichloride directly and dehydrated alcohol carries out esterification synthesizing phosphorous acid diethyl ester (referring to the flow diagram of accompanying drawing 1).
Its reaction formula is as follows:
1) main reaction: PCl
3+ 3C
2h
5oH → (C
2h
5o)
2pOH+C
2h
5cl+2HCl
2) side reaction: 3H
2o+PCl
3→ H
3pO
3+ 3HCl
（C
2H
5O）
2POH+HCl→C
2H
5OP(OH)
2+C
2H
5Cl
3C
2H
5OH+PCl
3→H
3PO
3+3C
2H
5Cl
This method is divided into again solvent method and non-solvent method, solvent method is in organic medium (as benzene and homologue thereof etc.), 30～40 DEG C of temperature of reaction, without or have under the condition of acid binding agent and directly react and make with dehydrated alcohol by phosphorus trichloride, the advantage of solvent method is to react not need low temperature environment, temperature of reaction is stablized easy to control, safe, and product content reaches 99%; Shortcoming is that technique is more complicated, and the yield of product is 80% left and right (collecting rate by phosphorus trichloride), and energy consumption is larger, and production cost is higher.
Non-solvent method is under the conditions such as solvent-free and negative pressure, to carry out liquid phase by phosphorus trichloride and dehydrated alcohol or gas-phase reaction makes.The advantage of non-solvent method is that speed of response is fast, product yield is high; Shortcoming is because phosphorus trichloride contains certain free phosphorus, in process of production when reaching after certain semi-invariant, running into ethanol can presence of fire accident, therefore require the purity of phosphorus trichloride must be high, the content of free phosphorus will be controlled at certain scope, and requires synthesis reaction temperature low, synthesis reaction temperature general control is at 6～8 degree, the yield of product just can reach 90%(and collect rate by phosphorus trichloride), finished product diethyl phosphite content is less than 98%, and stable poor.In addition, raffinate reclaims will control temperature while heavily steaming well, as overtemperature, the danger of decomposition explosion likely occurs under negative pressure, can produce a large amount of C simultaneously
2h
5cl and HCl gas, need a large amount of anticorrosion equipment and energy consumptions to reclaim, larger to the pollution of environment.
Summary of the invention
The object of the invention is to, provide a kind of by product and phosphorous acid producing while utilizing triethyl-phosphite to produce to react, the diethyl phosphite in recycling triethyl-phosphite by product; And product yield is high, purity is good, and equipment investment is few, production cost is low; The employing triethyl-phosphite by product of the features such as the quantity discharged with waste gas, waste water is few, environmental protection is produced the technique of diethyl phosphite.
The present invention realizes above-mentioned purpose by the following technical solutions:
Adopt triethyl-phosphite by product to produce a technique for diethyl phosphite, it is characterized in that, it is made up of following step:
The first step: preparation nitration mixture:
The mixed solution of the raffinate diethyl phosphite at the bottom of mixed solution and the tower of the overhead product diethyl phosphite of distillation tower tower top and ethanol and phosphorous acid is mixed with to diethyl phosphite mother liquor in the ratio of 1 ︰ 5, puts into diethyl phosphite mother liquor groove for subsequent use; Again phosphorous acid is put into nitration mixture still, then to disposable input diethyl phosphite mother liquor in nitration mixture still, temperature is risen to 120 DEG C and be incubated 2 hours after stirring; The proportioning of diethyl phosphite mother liquor and phosphorous acid is 1 ︰ 1, and the mixing speed of nitration mixture still is 130r/min, 75 DEG C of solvent temperatures.
Second step: esterification
The mixture of the diethyl phosphite mother liquor stirring in nitration mixture still and phosphorous acid is dropped into esterifying kettle, and the temperature of esterifying kettle is controlled between 120～130 DEG C, then drips triethyl-phosphite, and rate of addition is 800～820 ㎏/1 hour; The proportioning of triethyl-phosphite and mixture is 2 ︰ 1; Esterifying kettle mixing speed is 130r/min, and triethyl-phosphite drips rear insulation 3 hours, obtains the thick ester of diethyl phosphite.
The 3rd step: distillation
Thick diethyl phosphite ester is dropped into ￠ 600 × 24000mm rectifying tower with the speed of 20 ㎏/min, adopt the continuous negative pressure distillation of vacuum tightness >=-0.096MPa, the diethyl phosphite of distillation is from the middle part discharging of tower, distillation tower reboiler admission pressure is 0.4MPa, trim the top of column ratio is 1 ︰ 1, distillation tower reboiler still material temperature degree is 120 DEG C, and middle temperature control temperature is 110 DEG C, and temperature control temperature in top is 60 DEG C.
The 4th step: low-boiling point material and high boiling substance reuse
The impure alcohol low-boiling point material of distillation tower overhead product enters the low groove that boils, and phosphorous acid high boiling substance is from entering the height groove that boils at the bottom of tower; Raffinate diethyl phosphite at the bottom of the overhead product diethyl phosphite of tower top and mixed solution and the tower of ethanol and the mixed solution of phosphorous acid in the ratio discharging of 1 ︰ 5 to diethyl phosphite mother liquor groove, the preparation nitration mixture operation of the reuse the first step again, by product ethanol in low boiling enters nitration mixture still with the phosphorous acid in high boiling, at high temperature there is esterification, generate diethyl phosphite and water; Low-boiling point material ethanol, high boiling substance phosphorous acid and diethyl phosphite are mixed with diethyl phosphite mother liquor, are back to use nitration mixture still.
Be 98% by above its yield of explained hereafter diethyl phosphite, its product content is 99.0%.
The chemical equation of above-mentioned technique is as follows:
2C
2H
5OH+H
3PO
3?—→（C
2H
50）
2POH+2H
2O
（C
2H
50）
3P+H
2O—→（C
2H
50）
2POH?+C
2H
5OH
2（C
2H
50）
3P+H
3PO
3?—→3（C
2H
50）
2POH
The present invention's beneficial effect is compared with prior art:
1. throughput is large, technique is simple.
The technique that this employing triethyl-phosphite by product is produced diethyl phosphite only needs a set of nitration mixture still, a set of synthesis reactor, a set of rectifying tower just can complete whole production technique, production equipment is simple, and throughput is large, and facility investment is few, simple to operate, production efficiency is high.
2. triethyl-phosphite raw material is easy to get.
Raw materials for production are selected the by product of triethyl-phosphite, and its Main Components is triethyl-phosphite 60～70%; Diethyl phosphite 20～30%; Ethanol 8～10%, some triethyl-phosphite manufacturers cannot reuse and the waste material of processing.And the present invention is exactly by the by-product mixture recycling of triethyl-phosphite, by the triethyl-phosphite in phosphorous acid and by product, ethanol generation esterification, generate sub-phosphide diethyl ester.
3. consumption is low, yield is high.
After can separating by rectifying tower with excessive phosphorous acid, the impure alcohol that in reaction process, phosphorous acid generates with triethyl-phosphite is back to use nitration mixture still preparation nitration mixture, except rectifying tower can produce a small amount of plant machinery impurity and carbide waste residue, whole reactive system can not produce waste water, spent acid.Adopt triethyl-phosphite by product to produce technique product consumption per ton phosphorous acid (100%) the 196.1 ㎏ left and right of diethyl phosphite, consumption triethyl-phosphite (100%) 818.3 ㎏ left and right.Wherein most of raw material triethyl-phosphite is by-product waste, and marketable value cost is extremely low.
And phosphorus trichloride legal system to get the process recovery ratio of diethyl phosphite be 90%, produce diethyl phosphite product consumption per ton phosphorus trichloride (100%) 1120 ㎏ left and right, consumption ethanol (100%) 1125 ㎏ left and right.Can find out that thus phosphorus trichloride legal system is got the processes expend of diethyl phosphite high a lot, cost is also high a lot.
4. without waste water and gas, sewage disposal expense is low.
Because discharging high boiler material at the bottom of overhead product (also have an appointment except a small amount of diethyl phosphite 70% ethanol) and tower (except product also containing having an appointment 10% phosphorous acid) is back to use nitration mixture still, ethanol in overhead product reacts again and generates diethyl phosphite and water with the phosphorous acid of discharging at the bottom of tower, so, without any atmospheric pollution and waste water, sewage disposal expense is extremely low in whole production process.
Brief description of the drawings
Fig. 1 adopts phosphorus trichloride directly and dehydrated alcohol carries out the flow diagram of esterification synthesizing phosphorous acid diethyl ester;
Fig. 2 adopts triethyl-phosphite by product to produce the technological process block-diagram of diethyl phosphite.
Embodiment
Below by a specific embodiment, the present invention is further illustrated, taking the diethyl phosphite product of producing 1000Kg as example.
Triethyl-phosphite charging capacity 818.3 ㎏ in the present embodiment, phosphorous acid input amount is 196.1 ㎏, and the product diethyl phosphite of producing is 1000 ㎏, and the total recovery of triethyl-phosphite is 98%, and its content is 99.0%.
The first step: preparation nitration mixture
Nitration mixture still is selected enamel still, and mixing speed is 130r/min.(diethyl phosphite mother liquor derives from the raffinate at the bottom of overhead product and the tower of diethyl phosphite distillation tower to get 196.1 ㎏ diethyl phosphite mother liquors, component is ethanol 10%, diethyl phosphite 87%, phosphorous acid 3%) drop in nitration mixture still, nitration mixture still temperature is risen to 75 DEG C, open after stirring and dissolving, then to disposable input phosphorous acid 196.1 ㎏ in nitration mixture still, temperature rises to after 120 degree stir and is incubated 2 hours.
Second step: esterification
Esterifying kettle is enamel still, and mixing speed is 130r/min.The mixture of the diethyl phosphite mother liquor stirring in the first step nitration mixture still and phosphorous acid is dropped in esterifying kettle, open whipping appts, drip triethyl-phosphite, 818.3 ㎏ (100%) triethyl-phosphite is dripped for 1 hour, and lower the temperature and regulate rate of addition control temperature of reaction between 120～130 degree by chuck; The reason that temperature is controlled at 120～130 degree is that temperature, lower than 120 DEG C, easily produces impurity, and temperature, higher than 130 DEG C, easily causes vigorous reaction; After being added dropwise to complete, be incubated three hours at 130 DEG C, the thick ester of diethyl phosphite obtaining, and it is for subsequent use that thick diethyl phosphite ester is dropped into crude product groove.
The 3rd step: distillation
Thick diethyl phosphite ester is put into the rectifying tower of ￠ 600 × 24000mm with 20 ㎏/min speed, adopt the continuous negative pressure distillation of vacuum tightness >=-0.096MPa, the highly purified diethyl phosphite distilling out is from the continuous discharging in middle part of tower to diethyl phosphite finished pot.Distillation tower reboiler admission pressure is 0.4MPa, and trim the top of column ratio is 1 ︰ 1, is 120 DEG C by the control of distillation tower reboiler still material temperature degree, and middle temperature control is made as 110 DEG C, and top temperature control is made as 60 DEG C.
The 4th step: low-boiling point material and high boiling substance reuse.
The impure alcohol low-boiling point material of distillation tower overhead product enters the low groove that boils, and phosphorous acid high boiling substance is from entering the height groove that boils at the bottom of tower.Raffinate diethyl phosphite at the bottom of the overhead product diethyl phosphite of tower top and mixed solution and the tower of ethanol and the mixed solution of phosphorous acid in the ratio discharging of 1 ︰ 5 to diethyl phosphite mother liquor groove, the preparation nitration mixture operation of the reuse the first step again, by product ethanol in low boiling enters nitration mixture still with the phosphorous acid in high boiling, at high temperature there is esterification, generate diethyl phosphite and water.The diethyl phosphite product of producing is 1000 ㎏, and the total recovery of triethyl-phosphite is 98%, and its content is 99.0%.Low-boiling point material (ethanol), high boiling substance (phosphorous acid) are mixed with diethyl phosphite mother liquor with diethyl phosphite, are back to use nitration mixture still.
The above is the embodiment of this invention, above-mentioned not illustrating is construed as limiting flesh and blood of the present invention, person of an ordinary skill in the technical field is reading after this specification sheets and can above-mentioned embodiment made an amendment or is out of shape, and does not deviate from the spirit and scope of the invention.
Claims (1)
1. adopt triethyl-phosphite by product to produce a technique for diethyl phosphite, it is characterized in that, it is made up of following step:
The first step, preparation nitration mixture:
The mixed solution of the raffinate diethyl phosphite at the bottom of mixed solution and the tower of the overhead product diethyl phosphite of distillation tower tower top and ethanol and phosphorous acid is mixed with to diethyl phosphite mother liquor in the ratio of 1 ︰ 5, puts into diethyl phosphite mother liquor groove for subsequent use; Again phosphorous acid is put into nitration mixture still, then to disposable input diethyl phosphite mother liquor in nitration mixture still, temperature is risen to 120 DEG C and be incubated 2 hours after stirring; The proportioning of diethyl phosphite mother liquor and phosphorous acid is 1 ︰ 1, and the mixing speed of nitration mixture still is 130r/min, 75 DEG C of solvent temperatures;
Second step, esterification:
The mixture of the diethyl phosphite mother liquor stirring in nitration mixture still and phosphorous acid is dropped into esterifying kettle, and the temperature of esterifying kettle is controlled between 120～130 DEG C, then drips triethyl-phosphite, and rate of addition is 800～820 ㎏/1 hour; The proportioning of triethyl-phosphite and mixture is 2 ︰ 1; Esterifying kettle mixing speed is 130r/min, and triethyl-phosphite drips rear insulation 3 hours, obtains the thick ester of diethyl phosphite;
The 3rd step, distillation:
Thick diethyl phosphite ester is dropped into ￠ 600 × 24000mm rectifying tower with the speed of 20 ㎏/min, adopt the continuous negative pressure distillation of vacuum tightness >=-0.096MPa, the diethyl phosphite of distillation is from the middle part discharging of tower, distillation tower reboiler admission pressure is 0.4MPa, trim the top of column ratio is 1 ︰ 1, distillation tower reboiler still material temperature degree is 120 DEG C, and middle temperature control temperature is 110 DEG C, and temperature control temperature in top is 60 DEG C;
The 4th step, low-boiling point material and high boiling substance reuse:
The impure alcohol low-boiling point material of distillation tower overhead product enters the low groove that boils, and phosphorous acid high boiling substance is from entering the height groove that boils at the bottom of tower; Raffinate diethyl phosphite at the bottom of the overhead product diethyl phosphite of tower top and mixed solution and the tower of ethanol and the mixed solution of phosphorous acid in the ratio discharging of 1 ︰ 5 to diethyl phosphite mother liquor groove, the preparation nitration mixture operation of the reuse the first step again, by product ethanol in low boiling enters nitration mixture still with the phosphorous acid in high boiling, at high temperature there is esterification, generate diethyl phosphite and water; Low-boiling point material ethanol, high boiling substance phosphorous acid and diethyl phosphite are mixed with diethyl phosphite mother liquor, are back to use nitration mixture still.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107383086A (en) * | 2017-06-14 | 2017-11-24 | 浙江嘉华化工有限公司 | A kind of diethyl phosphite refining process |
| CN108003188A (en) * | 2017-12-25 | 2018-05-08 | 长春吉大天元化学技术股份有限公司 | A kind of new purification process of alkyl phosphoric acid esters compound |
| CN111995639A (en) * | 2020-09-10 | 2020-11-27 | 辽宁陶普唯农化工有限公司 | Synthesis method of diethyl phosphite |
| CN113387981B (en) * | 2021-06-22 | 2022-12-02 | 辽宁陶普唯农化工有限公司 | Synthesis method of diethyl phosphite |
| CN116396324B (en) * | 2023-03-17 | 2024-01-02 | 南雄志一精细化工有限公司 | Preparation method of light-colored diphenyl phosphite |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4045519A (en) * | 1976-09-16 | 1977-08-30 | Ethyl Corporation | Process for preparing dialkylphosphites |
| US4342709A (en) * | 1980-12-08 | 1982-08-03 | Stauffer Chemical Company | Process for producing diethyl phosphite |
| CN101405292A (en) * | 2006-03-17 | 2009-04-08 | 因温斯特技术公司 | Method for the purification of triorganophosphites by treatment with a basic additive |
-
2012
- 2012-09-18 CN CN201210346251.6A patent/CN102827202B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4045519A (en) * | 1976-09-16 | 1977-08-30 | Ethyl Corporation | Process for preparing dialkylphosphites |
| US4342709A (en) * | 1980-12-08 | 1982-08-03 | Stauffer Chemical Company | Process for producing diethyl phosphite |
| CN101405292A (en) * | 2006-03-17 | 2009-04-08 | 因温斯特技术公司 | Method for the purification of triorganophosphites by treatment with a basic additive |
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