PROCESS FOR PRODUCING C3 CHLORINATED ALKANE AND ALKENE COMPOUNDS

Abstract

A process for producing a reaction mixture comprising a plurality of C.sub.3 chlorinated alkane isomers comprising chlorinating a C.sub.3 chlorinated alkane starting material in a chlorination zone to produce the plurality of C.sub.3 chlorinated alkane isomers, the plurality of C.sub.3 chlorinated alkane isomers each having at least one more chlorine atom than the C.sub.3 chlorinated alkane starting material, wherein the concentration of the C.sub.3 chlorinated alkane starting material is controlled such that conversion of the C.sub.3 chlorinated alkane starting material to the plurality of C.sub.3 chlorinated alkane isomers, represented by the molar ratio of the C.sub.3 chlorinated alkane starting material:C.sub.3 chlorinated alkane isomers in the reaction mixture present in the chlorination zone, does not exceed about 40:60.

Claims

1. A process for producing a C.sub.3 chlorinated alkene comprising providing a mixture comprising a plurality of C.sub.3 chlorinated alkane isomers, the boiling point of at least two of the plurality of C.sub.3 chlorinated alkane isomers differing by 15 C., comprising subjecting the mixture to a selective dehydrochlorination step in a dehydrochlorination zone in which one of the at least two C.sub.3 chlorinated alkane isomers, a first C.sub.3 chlorinated alkane isomer, is selectively converted to a respective first C.sub.3 chlorinated alkene without the substantial dehydrochlorination of any of the other of the plurality of C.sub.3 chlorinated alkane isomers wherein some or all surfaces of the dehydrochlorination zone in which the process is carried out, which a stream rich in or consisting of the C.sub.3 chlorinated alkene will contact during dehydrochlorination, have an iron content of about 20% or less and/or are formed from non-metallic materials and/or plastic materials.

2.-30. (canceled)

31. The process of claim 1, wherein said non-metallic materials are selected from enamel, glass, impregnated graphite, and silicon carbide.

32. The process of claim 31, wherein said impregnated graphite is graphite impregnated with phenolic resin.

33. The process of claim 1, wherein said plastic materials are selected from polytetrafluoroethylene, perfluoroalkoxy, and polyvinylidene fluoride.

Description

[0358] The invention is further illustrated in the following Examples in which reference is made to the following figures:

[0359] FIG. 1 is a schematic drawing of an arrangement that may be employed in the processes of the present invention to achieve chlorination of a C.sub.3 chlorinated alkane starting material.

[0360] FIG. 2 is a schematic drawing of an arrangement that may be employed in the processes of the present invention to distill valuable product streams from a mixture comprising a plurality of C.sub.3 chlorinated alkane isomers.

[0361] FIGS. 3 and 4 are schematic drawings of arrangements that may be employed in the processes of the present invention for selectively dehydrochlorinating one isomer present in a plurality of C.sub.3 chlorinated alkane isomers.

[0362] FIG. 5 is a schematic drawing of an arrangement that may be employed in the processes of the present invention in which a mixture comprising a C.sub.3 chlorinated alkene may be subjected to aqueous treatment.

[0363] FIG. 6 is a schematic drawing of an arrangement that may be employed in the processes of the present invention to distill valuable product streams from a mixture comprising a C.sub.3 chlorinated alkene.

EXAMPLES

[0364] Glossary: in following tables, the following nomenclature is used

TABLE-US-00001 Short term Compound 1113-TeCPa 1,1,1,3-tetrachloropropane 1123-TeCPe 1,1,2,3-tetrachloropropene 1133-TeCPe 1,1,3,3-tetrachloropropene 1333-TeCPe 1,3,3,3-tetrachloropropene 11133-PCPa 1,1,1,3,3-pentachloropropane 11123-PCPa 1,1,1,2,3-pentachloropropane 111333-HCPa 1,1,1,3,3,3-hexachloropropane 111233-HCPa 1,1,1,2,3,3-hexachloropropane 111223-HCPa 1,1,1,2,2,3-hexachloropropane

Example 1

Chlorination of 1,1,1,3-Tetrachloropropane to Produce a Mixture of Pentachloropropanes

[0365] Chlorination was carried out as shown in FIG. 1 in a batch bubble column glass reactor (2) with external cooling circulations (3,7). The reactor was equipped with 250 W medium pressure mercury lamp immersed using quartz tube inside the column reactor. The cooling medium for coolers (4,8) was ethylene glycol solution. Gaseous chlorine (1) was introduced at the reactor bottom using a set of nozzles and liquid feedstock was initially filled using line (6). The temperature in the reactor was controlled to about 25 C.; the pressure in the reactor was atmospheric. The vent gas (10), hydrogen chloride with trace amounts of chlorine, was led to a caustic scrubber and the caustic was regularly analyzed for NaOCl and alkalinity in order to check HCl formation and chlorine loss via vent gas.

[0366] 460.7 kg of 1,1,1,3-Tetrachloropropane with a purity of 98.4% was initially filled into the chlorination reactor. Chlorine gas (83.1 kg) was introduced into the chlorination zone at a feeding rate of 8 kg/h. The 1,1,1,3-tetrachloropropane starting material was produced using the process and purity profile as described in WO2016/058566.

[0367] The amount of hydrogen chloride produced was 39.8 kg and the loss of chlorine was almost zero. The molar ratio of chlorine:1,1,1,3-tetrachloropropane was 47%. After about 10 hours the reaction was stopped and 502.7 kg of produced reaction mixture was analyzed by GC to provide the following results:

TABLE-US-00002 Compound Amount (wt. %) 1113-TeCPa 53.98% 11133-PCPa 34.93% 11123-PCPa 9.31% 111333-HCPa 0.74% 111233-HCPa 0.58% 111223-HCPa 0.34%

[0368] Calculated selectivity towards 11133PCPa was 79%.

[0369] As can be seen, control of the molar ratio of the starting material (1,1,1,3-tetrachloropropane):chlorinated alkane isomers (1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane) was limited to 59:41 which advantageously prevented the formation of high amounts of over chlorinated impurities.

Example 2

Purification of the Reaction Mixture from Example 1

[0370] As shown in FIG. 2, a batch vacuum glass distillation column (4) with accessories (5, 6, 7, 8, 9) was filled with plastic rings equal to about 25 theoretical stages efficiency. The vacuum in the column was set on appropriate level to keep the bottom of the boiler (2) temperature below 110 C.

[0371] 35.164 kg of reaction mixture was extracted from the reactor used in Example 1 and was initially filled to the column boiler (2) via line (1). Using reflux ratio of about 5 in sum, four fractions as distillates F1 (10.1), F2 (10.2), F3 (10.3), F4 (10.4.) and one fraction F5(DR) as distillation residue (3) were collected. The composition and mass of the fractions were following:

TABLE-US-00003 Distillation Feed F1 F2 F3 F4 F5(DR) Mass kg 35.164 18.411 13.289 2.206 0.181 0.476 1113-TeCPa % 53.98 97.93 0.12 0.00 0.00 0.00 11133-PCPa % 34.93 1.80 92.95 0.02 0.01 0.00 11123-PCPa % 9.31 0.00 6.90 99.68 68.29 0.81 111333-HCPa % 0.74 0.00 0.22 28.76 26.05 111233-HCPa % 0.58 0.15 45.72 111223-HCPa % 0.34 0.05 26.02

[0372] means concentration less than 0.005% wt., blank cell means not detectable=less than 1 ppm.

[0373] The following recycling scheme was then applied: [0374] Fraction F1: unreacted starting material stream, to be recycled to the chlorination Example 1 [0375] Fraction F2: chlorinated alkane isomers product stream, to be used as feedstock for next process step (see Examples 3, 4, 5) [0376] Fraction F3: single isomer product stream (second main product 11123-PCPa), to be used as feedstock for downstream processes e.g. as precursor of chlorinated or fluorinated alkenes. [0377] Fraction F4: to be recycled to the next distillation trial according to this Example 2 in order to built up concentration of 111333-HCPa impurity and after that to be further treated using e.g. high temperature chlorinolysis process to recover chlorine value or to be incinerated [0378] Fraction F5 distillation residue, to be further treated using e.g. high temperature chlorinolysis process to recover chlorine value or to be incinerated

[0379] Considering the sum of 1,1,1,3,3- and 1,1,1,2,3-pentachloropropanes obtained, the calculated yield of distillation (without recycling scheme) is 99.45%

[0380] As can be seen, from the initial mixture which was subjected to distillation (comprising 1,1,1,3-tetrachloropropane starting material, 1,1,1,2,3-pentachloropropane, 1,1,1,3,3-pentachloropropane and over-chlorinated impurities specifically), the 1,1,1,3-tetrachloropropane feedstock is separated as a major fraction F1 and sent back to the chlorination reaction zone. Fraction F2 is a mixture of 1,1,1,2,3-pentachloropropane and 1,1,1,3,3-pentachloropropane, wherein the content of 1,1,1,2,3-pentachloropropane is reduced (owing to the extraction of high purity 1,1,1,2,3-pentachloropropane as fraction F3). Fraction F3 is high purity 1,1,1,2,3-pentachloropropane which is isolated as a useful product in downstream processes. Minor fractions F4 and F5 are retrieved, and are either recycled or sent for recovery of chlorine content for example in a high temperature chlorinolysis process.

[0381] The preparation of fraction F2 of 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane was configured to have greater selectivity towards the 1,1,1,3,3-pentachloropropane isomer as the end product of interest in this synthesis is its corresponding alkene, 1,1,3,3-tetrachloropropene (1230za) the production of which is discussed below. Importantly, fraction F2 is free of starting alkane material (1,1,1,3-tetrachloropropane, 250fb) as 250fb can form 1,1,3-trichloropropene in the downstream dehydrochlorination steps. Separation of 1,1,3-trichloropropene from the desired 1,1,3,3-tetrachloropropene is problematic as 1,1,3-trichloropropene is a more reactive chlorinated alkene and it can be a catalyst poison for downstream hydrofluorination processes, for example the conversion of 1,1,3,3-tetrachloropropene to e.g. 1,1,1-trifluoro-3-chloro-1-propene (HFCO-1233zd), 1,1,1,3-tetrafluoro-1-propene (HFO-1234ze), 1,1,1,3,3-pentafluoropropane (HFC-245fa) and mixtures thereof.

Example 3

Highly Selective Dehydrochlorination of Mixture of 1,1,1,3,3- and 1,1,1,2,3-Pentachloropropanes

[0382] Fraction F2 (10.2) from Example 2 was fed into a continuous stirred tank glass reactor (2) as shown in FIG. 3. The reactor (2) consisted of a four neck glass flask equipped with a magnetic stirrer, thermometer, back cooler (4), feed and discharge pipes and hot oil heating bath. The feedstock (1) consisted of fraction F2 and about 100 ppm (based on the feedstock) added catalyst (FeCl.sub.3).Such a liquid feedstock was continuously fed by a dosing pump into the reactor. The formed HCl gas (3) was cooled down by means of a back cooler/condenser (4) and then (6) absorbed in an absorption column into the water to check the rate of HCl formation. The reaction mixture (7) was continuously automatically extracted from the reactor via a cooler (8) to the glass collection vessel (9) to keep the liquid level in the reactor on the constant value. Temperature of reaction was about 102 C., temperature of the subcooled reaction mixture was less than 20 C. and reaction pressure was atmospheric. The calculated mean residence time was 2:09 hour.

[0383] 4230 g of fraction F2 from Example 2 with added catalyst was continuously fed into the reactor at a rate of 145 g/h. Then, in sum, 450 g HCl was produced and absorbed in the absorption column. 3724 g of product mixture was extracted and analyzed by GC to provide the following results:

TABLE-US-00004 Feed Reaction mixture 1333-TeCPe (%) 0.10 1133-TeCPe (%) 0.02 69.58 1123-TeCPe (%) 0.20 11133-PCPa (%) 92.95 22.96 11123-PCPa (%) 6.90 7.00

[0384] Basic Parameters of Reaction Steps:

TABLE-US-00005 Reactor 1 Mean residence time 2:09 h Temperature 102 C. Pressure atm. Calculated 11133-PCPa conversion 75.3% Calculated selectivity 1133- 99.7% towards 1123-TeCPe

[0385] As can be seen from this example, the selectivity of the dehydrochlorination step in favour of the production of 1,1,3,3-tetrachloropropene was very high, at 99.7%

Example 4

Highly Selective Catalytic Dehydrochloration of the Mixture of Pentachloropropanes from Example 2

[0386] This dehydrochlorination step was carried out in a similar manner as described in Example 3 above, but in series or cascade of three continuously stirred tank glass reactors (2, 8, 14) as shown in FIG. 4. The liquid reaction mixture (7) was continuously extracted via line (7) from first reactor (2) and then fed to the second reactor (8), and then from the second reactor to the third reactor (14) via line (13).

[0387] From the third reactor, the said liquid reaction mixture (19) was extracted via the cooler (20) and collected in a glass flask. Each reactor was equipped with the same accessories as in Example 3. Catalyst (FeCl.sub.3) was added in the amount of 100 ppm only in the liquid feed (1) to the first reactor. Samples of reaction mixture were analyzed by GC upon extraction from each reactor. The formed hydrogen chloride gas (3, 9, 15) from each reactor was separately cooled down by means of a back cooler/condenser (4, 10, 16) and then (6, 12, 18) absorbed in separated absorption columns into the water to check the rate of HCl formation (and thus relate to the conversion) in each reactor. The operating temperature in the reactors was 101, 100 and 103 C., respectively. The temperature of the subcooled reaction mixture was less than 20 C. and the pressure was always atmospheric.

[0388] 5301 g of mixture of fraction 2 (the chlorinated alkane isomers stream comprising pentachloropropanes) from Example 2 with added catalyst was continuously fed into the first reactor at a rate of 552 g/h. 679 g hydrogen chloride was produced and absorbed in three absorption columns and 4573 g of product mixture was extracted from the third reactor. This product mixture was analyzed by GC to provide the following results:

TABLE-US-00006 Feed Reactor 1 Reactor 2 Reactor 3 1333-TeCPe (%) 0.11 0.13 0.06 1133-TeCPe (%) 0.02 48.26 67.56 76.38 1123-TeCPe (%) 0.07 0.12 0.15 11133-PCPa (%) 92.95 44.27 24.89 16.12 11123-PCPa (%) 6.90 7.14 7.16 7.12

[0389] Basic Parameters of Reaction Steps:

TABLE-US-00007 Reactor 1 Reactor 2 Reactor 3 Mean residence time 0:29 h 0:31 h 0:35 h Temperature 101 C. 100 C. 103 C. Pressure atm. atm. atm. Calculated 11133- 52.4% 73.2% 82.7% PCPa cumulative conversions Calculated cumulative 99.9% 99.8% 99.8% selectivity 1133- towards 1123-TeCPe

[0390] Examples 3 and 4 illustrate highly selective catalytic dehydrochlorination steps using a mixture of pentachloropropane isomers as a starting material. The isomeric ratio of 1,1,1,3,3-pentachloropropane to 1,1,1,2,3-pentachloropropane of 93:7 was achieved by the efficient distillation of the reaction mixture after chlorination which results in a single isomer stream being obtained which is rich in 1,1,1,2,3-pentachloropropane, as well as a plurality of C.sub.3 chlorinated alkane isomer stream being obtained having the increased isomeric ratio of 1,1,1,3,3-pentachloropropane:1,1,1,2,3-pentachloropropane. As demonstrated, dehydrochlorination can be carried out either in one reactor as in Example 3 or in series of three reactors as shown in Example 4, where selectivity of 1,1,3,3-tetrachloropropene over 1,1,2,3-tetrachloropropene of 99.8% was achieved by higher feedstock conversion rate and lower residence time.

EXAMPLE 5

Selective Dehydrochlorination of the Pentachloropropane Isomer Mixture Obtained in Example 1

[0391] Highly selective catalytic dehydrochlorination of mixture of pentachloropropanes was carried out in similar manner as in Example 4. However, a different feedstock was used, comprising a plurality of pentachloropropane isomers in the ratio in which they were produced in Example 1.

[0392] 5879 g of the mixed pentachloropropane isomer feedstock (isomer ratio of 11133:11123-PCPa=78.95:20.97) with added catalyst was continuously fed into the first reactor at a rate of 920 g/h. 631 g of hydrogen chloride was produced and absorbed in three absorption columns. 5194 g of product mixture was obtained from the third reactor and analyzed by GC to provide the following results:

TABLE-US-00008 Feed Reactor 1 Reactor 2 Reactor 3 1333-TeCPe (%) 0.11 0.07 0.08 1133-TeCPe (%) 0.02 47.87 61.43 66.55 1123-TeCPe (%) 0.29 0.43 0.51 11133-PCPa (%) 78.95 30.26 16.58 11.26 11123-PCPa (%) 20.97 21.24 21.20 21.25

[0393] Basic Parameters of Reaction Steps:

TABLE-US-00009 Reactor 1 Reactor 2 Reactor 3 Mean residence time 0:17 h 0:18 h 0:20 h Temperature 100 C. 101 C. 101 C. Pressure atm. atm. atm. Calculated 11133-PCPa 61.7% 79.0% 85.7% cumulative conversions Calculated cumulative 99.4% 99.3% 99.2% selectivity 1133- towards 1123-TeCPe

[0394] Example 5 illustrates a further highly selective dehydrochlorination step.

[0395] Selectivity of the desired C.sub.3 chlorinated alkene of 99.2% was achieved.

[0396] Isomer Selectivity Comparison Table:

TABLE-US-00010 Example 3 Example 4 Example 5 TeCPe isomer selectivity 99.7% 99.8% 99.2% 11123-PCPa conversion (loss) 3.32% 2.58% 2.95%

Example 6

Aqueous Treatment of C.SUB.3 .Chlorinated Alkene-Containing Mixtures

[0397] The reaction mixtures obtained from the dehydrochlorination steps performed in Examples 3, 4 and 5 were purified using a water treatment step carried out in a batch stirred glass reactor equipped with a high rotation-speed stirrer and temperature control system as shown on FIG. 5. 2% hydrogen chloride solution was mixed with distilled water (2). Cold mixture obtained from the dehydrochlorination steps (1) was mixed with the acidic solution in a 1:1 ratio and the resulting mixture stirred for about 5 hours. This aqueous treatment results in deactivation of catalytic system and hydrolysis and removal of medium-polar or polar compounds, particularly oxygenated, chlorinated byproducts. This treatment is conducted at a temperature of about 20-25 C. and preferably not more than about 50 C. After stirring, the stirrer was stopped and mixture was separated into two layersan upper aqueous layer and a lower organic layer. The lower layer was then extracted from the reactor (4) and dried using calcium chloride. The dried organic layer was then subjected to the distillation step in Example 7.

Example 7

Distillation of Aqueous Treated C.SUB.3 .Chlorinated Alkene Containing Mixture

[0398] Following the aqueous treatment step of Example 6, purification of the mixture obtained in Example 4 was efficiently carried out in a batch vacuum glass distillation column (4) with accessories as shown in FIG. 6.

[0399] The column was filled with ceramic Berl saddles equal to about 30 theoretical stages efficiency. The vacuum was set on appropriate level to keep the bottom of the boiler at a temperature below 110 C. 6430 g of the chlorinated alkene-containing mixture (1) was fed to the column boiler (2). Three fractions as distillates F1(10.1), F2(10.2), F3(10.3) and one fraction F4(DR) as distillation residue were collected (3) using a reflux ratio of about 5. The composition and mass of the fractions were as follows:

TABLE-US-00011 feed F 1 F 2 F 3 F 4(DR) mass (g) 6430 326 3905 435 1461 lights (%) 0.12 1.53 0.05 0.26 0.01 1333-TeCPe (%) 0.05 0.74 0.56 0.05 ND 1133-TeCPe (%) 75.22 97.66 99.36 66.90 0.14 1123-TeCPe (%) 0.14 0.01 0.01 2.23 0.04 11133-PCPa (%) 17.26 ND <0.005 30.08 67.38 11123-PCPa (%) 7.15 ND ND 0.00 32.08

[0400] The fractions were then processed as follows:

[0401] Fraction F1: was recycled for use in subsequent distillation steps corresponding to those carried out in this Example 7 in order to build up the concentration of light ends which can subsequently be purged and further treated using e.g. high temperature chlorinolysis process or incineration

[0402] Fraction F2 is the main product stream comprising the target chlorinated alkene (1,1,3,3-tetrachloropropene at high purity) with acceptably low levels of 1,1,2,3-tetrachloropropene. This product stream can be used as a feedstock in downstream processes e.g. as precursor of hydrofluorinated alkenes.

[0403] Fraction F3: was recycled for use in subsequent distillation steps corresponding to those carried out in this example in order to build up the concentration of 1,1,2,3-tetrachloropropene and other impurities which can subsequently be treated using e.g. high temperature chlorinolysis process or incineration, or which can be fed back for use in a chlorination step of the present invention, e.g. that described in Example 1.

[0404] Fraction F4(DR) was recycled to the distillation step of Example 2.

[0405] Calculated yield of distillation (without recycling scheme): 80.2%

Example 8

Influence of Molar Ratio of C.SUB.3 .Chlorinated Alkane Starting Material:C.SUB.3 .Chlorinated Alkane Isomer in Reaction Mixture During Chlorination Step

[0406] Chlorination of 1,1,1,3-tetrachloropropane to produce a mixture comprising 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane was carried out in a glass batch stirred reactor.

[0407] The reactor was equipped with a 125 W medium pressure mercury lamp. Temperature in the reactor was maintained at about 12 C. and the pressure in the reactor was atmospheric. The vent gas was bubbled into a caustic scrubber and this caustic was regularly analysed with respect to alkalinity in order to check the amount of hydrogen chloride formation. Chlorine gas was introduced into the reactor via a glass dip pipe with nozzle and was totally consumed in the reactor.

[0408] 504.4 g of 1,1,1,3-tetrachloropropane starting material with a purity of 99.9% was initially filled to the reactor. 198 g of chlorine was likewise fed at a rate of 33 g per hour. Samples from the reactor were taken regularly and were analyzed by GC to provide the following results:

TABLE-US-00012 Amount of chlorine based on stoichiometry ratio 20% 40% 60% 80% 100% Ratio of 1113-TeCPa starting 82:18 64:36 45:55 28:72 12:88 material towards all PCPa isomers Ratio of 11123-PCPa towards all 19.2 19.3 19.3 18.7 17.7 PCPa isomers (%) Ratio of HCPa towards all PCPa 1.0 2.3 4.4 7.7 15.0 isomers (%) Ratio of 111333-HCPa towards 2.1 5.1 10.2 18.9 39.9 11123-PCPa (%)

[0409] From the above results, it is observed that molar ratio between feedstock 1,1,1,3-tetrachloropropane and the isomeric product mixture significantly influences the formation of unwanted hexachloropropane compounds and thus yield. The undesired 1,1,1,3,3,3-hexachloropropane, which has boiling point close to 1,1,1,2,3-pentachloropropane, is difficult to remove and is also extremely reactive in the presence of trace of metals. As is apparent from the data shown here, control of the conversion of the starting material prevents formation of these problematic impurities.

[0410] Thus, to minimise production of problematic over chlorinated impurities, the conversion of the feedstock chloroalkane to the product chloropropanes, represented by the molar ratio between the feedstock chloroalkane and product chloropropanes, should be kept such that it does not exceed about 40:60, and more advantageously does not exceed about 60:40.

Example 9

Influence of Reaction Temperature During Chlorination

[0411] A series of chlorinations of 1,1,1,3-tetrachloropropane at a range of temperatures to produce a mixture of 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane were carried out in a glass batch stirred reactor. The reactor was equipped with a 125 W medium pressure mercury lamp. The operating temperature in the reactor was maintained at 10 C., 25 C., 50 C., 60 C., 95 C. and 115 C. Pressure in the reactor was atmospheric. The vent gas was bubbled into a caustic scrubber and the caustic was regularly analysed for the alkalinity in order to check hydrogen chloride formation. Chlorine was introduced into the reactor via glass dip pipe with nozzle and was totally consumed in the reactor.

[0412] 600 g of 1,1,1,3-tetrachloropropane with a purity of 99.9% was initially filled into the reactor. Chlorine was fed in to the reaction in a quantity equal to 60% by stoichiometry at a feeding rate of 100 grams per hour. The reaction mixture after completion was sampled from the reactor and was analysed by GC. The GC analytical results and kinetic study results are shown in the following tables:

TABLE-US-00013 Example No. 9.1 9.2 9.3 9.4 9.5 9.6 Reaction temperature 10 C. 25 C. 50 C. 60 C. 95 C. 115 C. 1113-TeCPa (%) 44.13 42.61 43.69 43.56 47.18 44.11 11133-PCPa (%) 42.15 43.20 41.77 41.31 37.93 39.63 11123-PCPa (%) 10.19 10.98 10.98 11.42 10.26 10.99 111333-HCPa (%) 0.97 1.11 1.17 1.16 1.38 1.41 111233-HCPa (%) 0.76 0.88 0.99 1.03 1.51 1.66 111223-HCPa (%) 0.45 0.49 0.51 0.51 0.39 0.26 Other (%) 1.36 0.74 0.89 1.00 1.35 1.94 Example No. 9.1 9.2 9.3 9.4 9.5 9.6 Reaction temperature 10 C. 25 C. 50 C. 60 C. 95 C. 115 Ratio of 11123-PCPa 19.47 20.27 20.82 21.66 21.29 21.71 towards all PCPa isomers (%) Ratio of HCPa isomers 4.15 4.56 5.05 5.12 6.81 6.58 towards PCPa isomers (%) Ratio of all heavies incl. 4.24 4.57 5.10 5.14 7.52 8.07 HCPa isomers towards PCPa isomers (%)

[0413] The above results demonstrate that reaction temperature in the chlorination zone influences the rate of formation of the hexachloropropanes and thus yield. The pentachloropropane isomeric selectivity remains relatively stable across the range of temperatures (i.e. surprisingly, selectivity cannot be controlled by the temperature in this particular). Accordingly, for the efficient synthesis of 1,1,1,3,3-pentachloropropane modest operating temperatures are preferred, e.g. below 60 C. or more preferably below 40 C.

Example 10

Continuous Chlorination of 1,1,1,3-Tetrachloropropane to Produce Isomer Mix

[0414] The chlorination of 1,1,1,3-tetrachloropropane to produce a mixture comprising 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane was carried out continuously in a glass CSTR stirred reactor.

[0415] The reactor consisted of a six-neck glass flask, equipped with a mechanical stirrer, a back-cooler, sets of inlets and outlet pipe connections, a thermos-probe and a 125 W high pressure mercury lamp housed in a quartz glass pipe and immersed into the reactor. The temperature in the reactor was maintained using a thermostat. The pressure in the reactor was atmospheric. The vent gas was linked through the back cooler into a HCl scrubber and then into a caustic scrubber. Both scrubbers were regularly analysed with respect to HCl and the chlorine content to monitor the amount of HCl formed as well as any unreacted chlorine. Chlorine gas was introduced into the reactor via a glass dip pipe with a nozzle outlet and the chlorine was almost totally consumed in the reactor.

[0416] The liquid feed was introduced in the reactor using a metering pump. The liquid reaction mixture left the reactor via an overflow pipe and passed into a collecting tank. Both the liquid feed mixture and chlorine were monitored by weight. The reaction mixture was analysed by GC.

[0417] The temperature in the reactor was about 34 C. There was no metal based catalyst employed in the liquid feed. Mean residence time in reactor was about 63 minutes. The molar amount of chlorine dosed based on the moles of liquid 1,1,1,3-tetrachloropropane introduced was about 22%. The results (in molar percentages) after reaching steady state are shown the following table:

TABLE-US-00014 Example No. FeCl.sub.3 = 0 Example 10 Reactor temperature ( C.) 34.1 Mean residence time (h) 1:03 Chlorine feed rate (mol % towards 1,1,1,3-TCPa) 22.0 1,1,1,3-TCPa conversion (mol %) 19.2 Ratio 11133-PCPa:11123 PCPa 79.1:20.9 Mol % byproducts:all isomers PCPa 2.41

[0418] As shown in this table, the control of conversion of the starting material to the pentachloropropane isomers by limiting the feed of chlorine resulted in the formation of low levels of impurities, and a high selectivity for 1,1,1,3,3-pentachloropropane.

[0419] Full details of the composition obtained in this example are provided below. As can be seen, the reaction was highly selective towards the two pentachloropropane isomers of interest, 1,1,1,2,3-pentachloropropane and 1,1,1,3,3-pentachloropropane. In other words, very low levels of hexachlorinated propane impurities were produced and no detectable levels of pentachloropropane isomers other than the isomers of interest were obtained.

TABLE-US-00015 Example No. 10 Compound Amount (wt. %) 113-TCPe 0.004 1333-TeCPe na 1133-TeCPe 0.000 1113-TeCPa 77.857 1123-TeCPe na 11133-PCPa 17.018 11123-PCPa 4.490 111333-HCPa 0.280 111233-HCPa 0.194 111223-HCPa 0.124

Example 11

Influence of Catalyst and Temperature

[0420] The chlorination of 1,1,1,3-tetrachloropropane to produce a mixture comprising 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane was carried out continuously in a glass CSTR stirred reactor.

[0421] The reactor consisted of a six-neck glass flask, equipped with a mechanical stirrer, a back-cooler, sets of inlets and outlet pipe connections, a thermos-probe and 125 W high pressure mercury lamp housed in a quartz glass pipe and immersed into the reactor. The temperature in the reactor was maintained using a thermostat. The pressure in the reactor was atmospheric. The vent gas was linked through the back cooler into a HCl scrubber and then into a caustic scrubber. Both scrubbers were regularly analysed with respect to HCl and the chlorine content to monitor the amount of HCl formed as well as any unreacted chlorine. Chlorine gas was introduced into the reactor via a glass dip pipe with a nozzle outlet and the chlorine was almost totally consumed in the reactor.

[0422] The liquid feed was introduced in the reactor using a metering pump. The liquid reaction mixture left the reactor via an overflow pipe and passed into a collecting tank. Both the liquid feed mixture and chlorine were monitored by weight. A defined amount of hydrochloric acid was added into the reaction mixture collecting tank in order to de-activate the metal-based catalyst. Both the liquid feed mixture and chlorine were monitored by weight. The reaction mixture was analysed by GC.

[0423] The liquid feed was initially dried by CaCl.sub.2 and, after filtration, doped by a defined amount of the metallic catalyst (anhydrous FeCl.sub.3). This liquid feed was then held under a dry nitrogen atmosphere in order to prevent contamination by atmospheric moisture. The content of moisture in the liquid feed was about 12-46 ppmw (trial to trial). The content of 1,1,1,3-tetrachloropropane in the feed was more than 99.9%.

[0424] For the first trial, a range of temperatures were employed, namely about 40 C., 55 C., 90 C., 105 C. respectively. The amount of anhydrous FeCl.sub.3 in the liquid feed was 12.5 ppmw. Mean residence time in reactor was about 30 minutes. The molar amount of chlorine dosed based on the moles of liquid 1,1,1,3-tetrachloropropane introduced was about 20%. The results after reaching steady state are shown the following table (all ratios in molar percent).

TABLE-US-00016 Example No. 11.1 11.2 11.2 11.4 Reactor temperature 41.2 84.7 90.1 105.1 ( C.) Mean residence time 0:32 0:32 0:31 0:31 (h) Chlorine feed rate 19.7 19.7 19.4 19.8 (mol % towards 1,1,1,3-TCPa) 1,1,1,3-TCPa conversion 17.2 17.5 17.3 20.7 (mol %) Ratio 11133- 78.9:21.1 70.8:29.2 64.1:35.9 17.8:82.2 PCPa:11123 PCPa % byproducts:all 2.28 2.97 3.25 3.61 isomers PCPa

[0425] As can be seen, isomeric selectivity can be influenced by temperature control. Again, by minimising the conversion of the starting material to the isomers of interest (through control of the amount of chlorine provided), this provides control over the levels of impurities that are formed.

[0426] The following table illustrates the full compositions obtained from the runs in this example. As can be seen, advantageously, very low levels of hexachlorinated propanes were obtained. Further, no pentachloropropane isomers other than the isomers of interest (1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane) were obtained. Thus, a very high selectivity towards those isomers was advantageously achieved.

TABLE-US-00017 Example No. 11.1 11.2 11.3 11.4 Compound Amount (wt. %) 113-TCPe 0.000 0.055 0.125 2.502 1333-TeCPe 0.002 0.002 0.002 0.008 1133-TeCPe 0.000 0.006 0.016 0.138 1113-TeCPa 80.078 79.796 79.981 77.118 1123-TeCPe na 0.017 0.024 0.051 11133-PCPa 15.282 13.764 12.281 3.466 11123-PCPa 4.088 5.690 6.871 15.985 111333-HCPa 0.214 0.210 0.170 0.021 111233-HCPa 0.163 0.300 0.376 0.568 111223-HCPa 0.108 0.106 0.112 0.054

Example 12

Influence of Conversion of Starting Material and Chlorine Feed on Byproduct Formation

[0427] Chlorination of 1,1,1,3-tetrachloropropane to produce a mixture comprising 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane was carried out according to Example 10, but with an increased amount of chlorine, to increase the conversion of 1,1,1,3-tetrachloropropane. The molar amount of chlorine dosed based on the moles of 1,1,1,3-tetrachloropropane was about 40%. The results after reaching steady state are shown in the following table (all ratios in molar percent).

TABLE-US-00018 Example No. 12.1 12.2 12.3 12.4 Reactor temperature 80.5 84.9 89.8 94.9 ( C.) Mean residence time 0:30 0:30 0:30 0:31 (h) Chlorine feed rate 38.8 38.8 39.4 39.4 (mol % towards 1,1,1,3-TCPa) 1,1,1,3-TCPa conversion 33.5 33.9 34.9 33.3 (mol %) Ratio 11133- 78.1:21.9 75.1:24.9 70.6:29.4 64.7:35.3 PCPa:11123 PCPa % byproducts:all 6.23 6.69 7.19 7.60 isomers PCPa

[0428] It can be seen that, in comparison to Example 10, the amount of formed byproducts, e.g. 111333-HCPa, is higher when using a greater molar ratio of chlorine:1,1,1,3-TCPa in the feed to the reactor.

[0429] The following table illustrates the full compositions obtained from the runs in this example. As can be seen, advantageously, very low levels of hexachlorinated propanes were obtained. Further, no pentachloropropane isomers other than the isomers of interest (1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane) were obtained. Thus, a very high selectivity towards those isomers was advantageously achieved.

TABLE-US-00019 Example No. 12.1 12.2 12.3 12.4 Compound Amount (wt. %) 113-TCPe 0.012 0.021 0.046 0.020 1333-TeCPe na na na na 1133-TeCPe 0.005 0.006 0.010 0.012 1113-TeCPa 62.312 61.896 60.826 62.476 1123-TeCPe na na na 0.035 11133-PCPa 27.418 26.510 25.484 22.307 11123-PCPa 7.685 8.795 10.587 12.147 111333-HCPa 1.055 1.042 0.953 0.754 111233-HCPa 0.949 1.112 1.384 1.551 111223-HCPa 0.471 0.495 0.557 0.551

Example 13

Influence of Conversion of 1,1,1,3-Tetrachloropropane and Residence Time

[0430] Chlorination of 1,1,1,3-tetrachloropropane to produce a mixture comprising 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane was carried out according to Example 10. However, an increased amount of chlorine was introduced in order to increase the conversion of feedstock 1,1,1,3-tetrachloropropane. The molar amount of chlorine dosed based on the moles of 1,1,1,3-tetrachlorpropane was about 40%. The mean residence time was about 54 minutes. The results after reaching steady state are shown the following table (all ratios in molar percent).

TABLE-US-00020 Example No. 13.1 13.2 13.3 13.4 Reactor temperature 80.2 85.0 90.1 94.8 ( C.) Mean residence time 0:54 0:54 0:54 0:55 (h) Chlorine feed rate 39.4 39.3 39.1 40.6 (mol % towards 1,1,1,3-TCPa) 1,1,1,3-TCPa conversion 34.5 34.8 34.9 36.3 (mol %) Ratio 11133- 73.6:26.4 67.6:32.4 54.3:45.7 34.4:65.6 PCPa:11123 PCPa % byproducts:all 6.87 7.35 7.88 7.39 isomers PCPa

[0431] In comparison to the results obtained in Examples 10 and 11, the amount of byproducts formed is greater when conversion of the 1,1,1,3-tetrachloropropane starting material to the isomers of interest is increased and when a higher amount of chlorine is fed into the system. As can also be seen, the selectivity towards 1,1,1,2,3-pentachloropropane is influenced by residence time.

[0432] The following table illustrates the full compositions obtained from the runs in this example. As can be seen, advantageously, low levels of hexachlorinated propanes were obtained. Further, no pentachloropropane isomers other than the isomers of interest (1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane) were obtained. Thus, a very high selectivity towards those isomers was advantageously achieved.

TABLE-US-00021 Example No. 13.1 13.2 13.3 13.4 Compound Amount (wt. %) 113-TCPe 0.029 0.061 0.230 1.313 1333-TeCPe na 0.000 0.001 0.004 1133-TeCPe 0.006 0.012 0.029 0.124 1113-TeCPa 61.243 60.912 60.859 59.646 1123-TeCPe 0.017 0.023 0.036 0.053 11133-PCPa 26.372 24.297 19.348 12.302 11123-PCPa 9.473 11.655 16.270 23.473 111333-HCPa 1.007 0.882 0.570 0.301 111233-HCPa 1.208 1.470 1.901 2.079 111223-HCPa 0.534 0.551 0.610 0.490

Example 14

Influence of Increased Amount of Catalyst

[0433] Chlorination of 1,1,1,3-tetrachloropropane to produce a mixture comprising 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane was carried out according to Example 10, but with increased amount of the catalyst FeCl.sub.3 in the amount of 50 ppmw into the liquid feedstock. The results after reaching steady state are shown the following table (all ratios in molar percent).

TABLE-US-00022 Example No. 14.1 14.2 14.3 14.4 Reactor temperature 60.2 70.0 80.0 84.8 ( C.) Mean residence time 0:32 0:32 0:32 0:33 (h) Chlorine feed rate 19.3 19.2 19.3 19.8 (mol % towards 1,1,1,3-TCPa) 1,1,1,3-TCPa conversion 17.2 17.2 17.3 19.2 (mol %) Ratio 11133- 75.5:24.5 69.6:30.4 47.9:52.1 33.2:66.8 PCPa:11123 PCPa % byproducts:all 2.46 2.83 3.28 3.46 isomers PCPa

[0434] In comparison to Example 10, it can be seen that the increased amount of catalyst used permits chlorination to proceed at lower reaction temperature, without any significant change in isomeric selectivity.

[0435] The following table illustrates the full compositions obtained from the runs in this example. As can be seen, advantageously, very low levels of hexachlorinated propanes were obtained. Further, no pentachloropropane isomers other than the isomers of interest (1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane) were obtained. Thus, a very high selectivity towards those isomers was advantageously achieved.

TABLE-US-00023 Example No. 14.1 14.2 14.3 14.4 Compound Amount (wt. %) 113-TCPe 0.000 0.042 0.332 1.955 1333-TeCPe na na 0.002 0.008 1133-TeCPe 0.002 0.005 0.021 0.094 1113-TeCPa 80.118 80.097 80.068 78.615 1123-TeCPe na na 0.008 0.023 11133-PCPa 14.568 13.349 9.020 6.143 11123-PCPa 4.718 5.837 9.822 12.380 111333-HCPa 0.210 0.189 0.095 0.059 111233-HCPa 0.206 0.287 0.455 0.479 111223-HCPa 0.117 0.136 0.127 0.092

Example 15

Continuous Chlorination Zones Operated in Sequence

[0436] Chlorination of 1,1,1,3-tetrachloropropane to produce a mixture comprising 1,1,1,3,3-pentachloropropane and 1,1,1,2,3-pentachloropropane was carried out continuously in a reactor according to the procedure set out above in Example 10. Chlorination of the 1,1,1,3-tetrachloropropane was carried out in two CSTR reactors operated in sequence. The reaction mixture from the first CSTR was collected and then used as a liquid feedstock for the second CSTR. The total amount of 20 mol % of chlorine was added together in two steps. The results after reaching steady state are shown the following table (all ratios in molar percent).

TABLE-US-00024 Example No. 15.1 15.2 Cascade step 1 2 Reactor temperature 35 34 ( C.) Mean residence time 1:01 1:00 (h) Chlorine feed rate 10.3 11.1 (mol % towards 1,1,1,3-TCPa) 1,1,1,3-TCPa conversion 9.4 19.5 (mol %) Ratio 11133- 79.2:20.8 79.1:20.9 PCPa:11123 PCPa % byproducts:all 0.90 1.75 isomers PCPa

[0437] As can be seen by comparing these results from those obtained in Example 10, conducting the chlorination reaction in two chlorination zones operated in sequence produces less by-products while achieving the same degree of conversion.

TABLE-US-00025 Example No. 15.1 15.2 Compound Amount (wt. %) 113-TCPe 0.004 0.009 1333-TeCPe na na 1133-TeCPe 0.001 0.001 1113-TeCPa 89.054 77.588 1123-TeCPe na na 11133-PCPa 8.596 17.357 11123-PCPa 2.258 4.581 111333-HCPa 0.057 0.204 111233-HCPa 0.032 0.141 111223-HCPa 0.024 0.085