CN100427442C

CN100427442C - Improved preparing process for 1,1,1,3,3-pentachloro propane

Info

Publication number: CN100427442C
Application number: CNB2005101368609A
Authority: CN
Inventors: 吴江平; 韩国庆; 丁元胜; 方小青; 杨箭
Original assignee: Zhejiang Lantian Environmental Protection Hi Tech Co Ltd
Current assignee: Zhejiang Lantian Environmental Protection Hi Tech Co Ltd
Priority date: 2005-12-19
Filing date: 2005-12-19
Publication date: 2008-10-22
Anticipated expiration: 2025-12-19
Also published as: CN1986507A

Abstract

The improved 1, 1, 1, 3, 3-pentachloro propane preparing process includes the telomerization of carbon tetrachloride and chloroethylene in the presence of iron powder catalyst and phosphoric acid ester cocatalyst, settlement separating the reaction product to eliminate coarse iron powder and un-reacted material, water treating the product to eliminate fine iron powder, iron ion complex dissolved in the product and iron salt, and final decompression rectifying to obtain target product. The technological process of the present invention has greatly reduced scaling, decomposition and blocking during product rectification, and is favorable to industrial production.

Description

1,1,1,3, the improvement preparation method of 3-pentachloropropane

Technical field

The present invention relates to a kind of 1,1,1,3, the improvement preparation method of 3-pentachloropropane.

Background technology

1,1,1,3,3-pentachloropropane (being called for short HCC240) is preparation 1,1,1,3, the intermediate of 3-pentafluoropropane.1,1,1,3, the 3-pentafluoropropane is called for short HFC245fa, has good physical and chemical performance, the physical and chemical performance that is widely used in field, especially HFC245fa such as cleaning, foaming, refrigeration and HCFC141b and CFC11 is close, and its ODP value is zero, atmospheric ozone layer is not had the potential destruction, so HFC245fa is the ideal substitute of HCFC141b and CFC11.

It is documented, HCC240 can make by the telomerization of tetracol phenixin and vinylchlorid, as according to U.S. Pat 6,313,360B1, telomerization in the presence of iron powder catalyzer and phosphoric acid ester promotor prepares HCC240 by tetracol phenixin and vinylchlorid, preparation technology by this patent, coarse grained iron powder catalyzer, after reaction is finished,, return the reactor recycle by settlement separate, but in this preparation technology, the parts of fine iron powder is suspended in the product stream, is difficult to be separated and recycle by sedimentation, in addition, part iron powder catalyzer can form complex compound or iron salt dissolved in product stream with the phosphoric acid ester promotor in reaction process, obviously, these iron complexs and molysite also can't be removed by settlement separate, and these are suspended in iron powder and the iron complex and the molysite that are dissolved in the product stream in the product stream, as separating treatment in addition not, make troubles not only can for the distillation operation of product also can influence product yield.

Summary of the invention

The objective of the invention is to overcome the weak point in the prior art, handle by washing, remove 1,1,1,3, be suspended in thin iron powder catalyzer and the iron complex and the molysite that are dissolved in the product stream in the product stream in the 3-pentachloropropane production process, improve the distillation operation of product, improve product yield, be beneficial to suitability for industrialized production.

By the technology of the present invention, 1,1,1,3, the 3-pentachloropropane is that to adopt tetracol phenixin and vinylchlorid be that raw material makes through telomerization in the presence of catalyzer and promotor, and the telomerization product is by the crude reaction thing liquid behind settlement separate removal crude iron powder and the recovery unreacting material, handle by washing in advance, carry out rectification under vacuum again.Concrete technical solution may further comprise the steps:

A. raw material tetracol phenixin and vinylchlorid carry out the liquid phase telomerization and prepare the HCC240 reaction product in the presence of catalyzer and promotor;

B. reaction product is by the settlement separate catalyzer that goes, and reclaims this catalyzer, is circulated to step a and continues to use;

C. the reaction product that obtains after sedimentation reclaims unreacted raw material by flash distillation or underpressure distillation and is circulated to step a use;

D. reclaim reacting coarse product behind the raw material through washing, remove and carry secretly in the reaction solution and the dissolved catalyzer, obtain the HCC240 crude product;

The e.HCC240 crude product obtains target product through rectification under vacuum.

The present invention is tetracol phenixin and vinylchlorid at the liquid phase telomerization raw material described in the processing step a, and its suitable mole proportioning is 1.1-3.0: 1; Described catalyzer is an iron powder, and its consumption is the 0.5--5% of vinylchlorid mole number; Described promotor adopts phosphoric acid ester, as trimethyl phosphite 99, triethyl phosphate or tributyl phosphate etc., and triethyl phosphate preferably, catalyzer and promotor mol ratio are 0.5-5.0: 1; Tetracol phenixin and vinylchlorid carry out the liquid phase telomerization in the presence of catalyzer and promotor temperature of reaction is 80--115 ℃.

Tetracol phenixin and vinylchlorid obtain the telomerization product through telomerization in the presence of catalyzer and promotor, mainly comprise target product HCC240, unreacted tetracol phenixin and vinylchlorid, the catalyzer and the promotor that do not consume in this product, also have a spot of by product such as dimer etc.According to another US6,313, the 360B1 explanation, in this reaction, part iron powder catalyzer can with phosphoric acid ester promotor generation chemical action, generate the iron ion complex compound, iron powder also can form iron(ic) chloride and iron protochloride in reaction process, therefore, obviously also include these byproducts of reaction in the product.

The present invention is in processing step b, adopt settled method to separate the catalyzer iron powder that does not consume, sedimentation can directly also can be moved to special-purpose sedimentation still and carry out in the telomerization still, settling time is long more, catalyst separating is abundant more, but practice shows, what the energy generation was settlement separate only is than the crude iron powder, total some thin iron powder can be suspended in and be difficult in the reactant by sedimentation Separation and Recovery in addition, though the settling time does not have particular requirement, but for shortening the operational cycle, enhance productivity, the settling time fix on 0.5-5 hour comparatively suitable.After sedimentation finishes, take out upper strata reactant liquid and enter processing step c, the catalyzer that settled iron powder can be used as (containing a spot of telomerization product) telomerization next time directly uses.

The crude reaction thing liquid that obtains after with sedimentation in processing step c reclaims unreacted raw material tetracol phenixin and vinylchlorid by flash distillation or underpressure distillation.When telomerization, for the selectivity that improves target product and the transformation efficiency of vinylchlorid, the general excessive method of tetracol phenixin that adopts, so reclaiming in the unreacted raw material by flash distillation or underpressure distillation, the overwhelming majority is a tetracol phenixin, and content of vinylchloride is less, and the raw material of these recovery can directly return among the processing step a and use as the telomerization raw material.

The present invention is in processing step d, telomerization product after reclaiming raw material among the step C is passed through washing, remove and carry secretly in the product and the dissolved catalyzer, obtain the HCC240 crude product, said here carrying secretly with the dissolved catalyzer is meant that mainly a part does not obtain settlement separate thin iron powder and aforementioned iron ion complex compound and the molysite that generates in the reaction of telomerization process neutralising phosphoric acid ester thereof among the processing step b.Carry secretly in the product with the dissolved catalyzer as not removing, can influence the operation of distillation system on the one hand, as coking, blocking pipe etc., can aggravate the decomposition of target product HCC240 when rectifying on the other hand, generate impurity effect product yield and quality such as tetrachloro propylene.In addition, if this part dissolved catalyzer picture U.S. Pat 6,313, said recovery is used for telomerization among the 360B1, and data show that the selectivity of target product and the transformation efficiency of vinylchlorid are had certain influence.

Washing can be adopted conventional method, as water and product are stirred in reactor or adverse current in packing tower, water is fully contacted with product, leave standstill separatory after the washing, lower floor is the HCC240 crude product, the washing water consumption is generally 0.1-10 times of amount of crude product, by washing, can remove iron more than 90% and iron ion in the product.

The present invention is in processing step d, and the HCC240 crude product obtains refining target product through rectification under vacuum, and product content is greater than 99%.

As production technique of the present invention, each step can adopt the interrupter method operation, for enhancing productivity, also can be by well-designed, adopt the serialization production operation, before product rectifying, remove by washing proposed by the invention operation and to carry secretly in the HCC240 crude product or the dissolved catalyzer, can be easy to adopt the rectification under vacuum purified product, seldom occur to stop up serious phenomenon of coking at the bottom of rectifying tower and pipeline and the still in the operation, this helps prolonging the operational cycle that serialization is produced greatly, enhances productivity, simultaneously the decomposition of product when rectifying be can reduce, product yield and quality improved.

Specific embodiment

Embodiment 1

In 1 liter of band agitated autoclave, drop into tetracol phenixin 960g, iron powder 10g, triethyl phosphate 10g, after the sealing, with the oxygen in the nitrogen replacement still, heat temperature raising to 100 ℃, continuous or semicontinuous input vinylchlorid 225g in 4 hours, insulation reaction is 2 hours then; Autoclave left standstill cooling after 2 hours, sucking-off upper strata reaction clear liquid, the catalyzer that does not consume is stayed in the still, unreacting material is reclaimed in the underpressure distillation of reaction solution elder generation, use the 400ml water washing then, standing demix takes out lower floor and reacts thick product, after rectification under vacuum obtains target product HCC240, content is 99.1%.

The reaction solution gas chromatographic analysis the results are shown in Table 1.

Embodiment 2,3,4

Substantially feed intake and operate, just change the catalyzer iron powder into 3.5g, and apply mechanically the not spent catalyst of staying in the autoclave with embodiment 1.The results are shown in Table 1.

In the device of rectification under vacuum purification HCC240, do not find simultaneously distillation residual liquid coking and rectifying tower phenomenon of blocking.

Table 1

Embodiment	Conversion rate of vinyl chloride	The vinylchlorid selectivity
Embodiment	Conversion rate of vinyl chloride	The vinylchlorid selectivity	1	98.7％	98.0％
2	98.9％	98.1％	1	98.7％	98.0％
2	98.9％	98.1％	3	99.2％	98.2％
4	99.1％	98.1％	3	99.2％	98.2％

Embodiment 5

Will be through the HCC240 crude product rectification under vacuum respectively of washing and not washing, the HCC240 product content table 2 that obtains.

Table 2

	HCC240	The tetrachloro propylene	Other
	HCC240	The tetrachloro propylene	Other	Washing	99.74％	Do not detect	0.26％
Not washing	99.50％	0.09％	0.41％	Washing	99.74％	Do not detect	0.26％

Claims

One kind by tetracol phenixin and vinylchlorid in the presence of iron powder catalyzer and phosphoric acid ester promotor by telomerization preparation 1,1,1,3, the method of 3 one pentachloropropane, it is characterized in that the telomerization product by the crude reaction thing liquid behind settlement separate removal crude iron powder and the recovery unreacting material, passes through washing in advance and handles, carry out rectification under vacuum again.
2. according to claim 1 said 1,1,1,3, the preparation method of 3 one pentachloropropane, the molar ratio that it is characterized in that reaction raw materials tetracol phenixin and vinylchlorid is 1.1-3.0: 1, the consumption of catalyzer iron powder is the 0.5-5% of vinylchlorid mole number, the molar ratio of catalyzer iron powder and promotor phosphoric acid ester is 0.5-5.0: 1, and temperature of reaction is 80-115 ℃.
3. according to claim 1 or 2 said 1,1,1,3, the preparation method of 3 one pentachloropropane is characterized in that used promotor is trimethyl phosphite 99, triethyl phosphate or tributyl phosphate.
4. said 1,1,1,3 according to claim 1, the preparation method of 3 one pentachloropropane, in it is characterized in that handling by settlement separate crude reaction thing liquid washing after removing the crude iron powder and reclaiming unreacting material the consumption of water be amount of crude product 0.1-10 doubly.