EP1885676A2

EP1885676A2 - Method for converting polyhydroxylated aliphatic hydrocarbons into chlorohydrins

Info

Publication number: EP1885676A2
Application number: EP06755273A
Authority: EP
Inventors: Patrick Gilbeau
Original assignee: Solvay SA
Current assignee: Solvay SA
Priority date: 2005-05-20
Filing date: 2006-05-19
Publication date: 2008-02-13
Also published as: US20080200701A1; WO2006100312A3; WO2006100314A1; MX2007014523A; CA2608961C; US20090131631A1; CA2608816A1; CN102603474A; EP2284162A2; CN101052606B; US8106245B2; CN101098843A; US8389777B2; US7906691B2; WO2006100315A3; WO2006100315A2; BRPI0610745A2; TW200700361A; TW200700401A; EP2284162A3

Abstract

The invention concerns a method for preparing chlorohydrin which consists in (a) reacting a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture thereof, with a chlorinating agent to obtain a mixture containing chlorohydrin, esters of chlorohydrin and water; (b) subjecting at least one fraction of the mixture obtained at step (a) to a distillation and/or stripping treatment to obtain one part concentrated in water, in chlorohydrin and in ester of chlorohydrin; (c) subjecting at least one fraction of the part obtained at step (b) to a separation process in the presence of at least one additive to obtain a portion concentrated in chlorohydrin and in esters of chlorohydrin and which contains less than 40 wt. % of water.

Description

Process for converting polyhydroxylated aliphatic hydrocarbons to chlorohydrins

The present patent application claims the benefit of the patent application FR 05.05120 and the patent application EP 05104321.4, filed on May 20, 2005 and the provisional US patent applications 60/734659, 60/734627, 60/734657, 60 / 734658, 60/734635, 60/734634, 60/734637 and 60/734636, filed November 8, 2005, the contents of which are hereby incorporated by reference.

The present invention relates to a process for preparing a chlorohydrin.

Chlorohydrins are reaction intermediates in the manufacture of epoxides. Dichloropropanol, for example, is a reaction intermediate in the manufacture of epichlorohydrin and epoxy resins (Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Edition, 1992, Vol 2, page 156, John Wiley & Sons, Inc.). .

According to known processes, dichloropropanol can be obtained in particular by hypochlorination of allyl chloride, by chlorination of allyl alcohol and by hydrochlorination of glycerol. The latter process has the advantage that dichloropropanol can be obtained from fossil raw materials or renewable raw materials, and it is known that petrochemical natural resources, from which fossil fuels are derived, for example petroleum, natural gas or coal, available on the earth are limited.

The application WO 2005/054167 of SOLVAY S.A. describes a process for the manufacture of dichloropropanol by reaction between glycerol and hydrogen chloride in the presence of a catalyst such as adipic acid. In this process, a mixture of water and dichloropropanol is separated by azeotropic distillation of which dichloropropanol is then separated by decantation. Dichloropropanol contains significant amounts of water, the elimination of which can lead to a cost prohibitive for the economy of the process.

The object of the invention is to provide a method of manufacturing a chlorohydrin which does not have these disadvantages. The invention therefore relates to a process for preparing a chlorohydrin comprising the following steps: a) A polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof is reacted with a chlorinating agent to obtain a mixture containing chlorohydrin, chlorohydrin esters and chlorohydrin. b) at least a fraction of the mixture obtained in step (a) is subjected to a distillation and / or stripping treatment so as to obtain a concentrated portion of water, chlorohydrin and chlorohydrin esters; subjecting at least a fraction of the part obtained in step (b) to a separation operation in the presence of at least one additive so as to obtain a concentrated portion of chlorohydrin and of chlorohydrin esters and which contains less than 40% by weight of water.

The separation operation in step (c) is preferably a decantation.

It has been found that by using at least one additive in step (c) of the process according to the invention, it is possible to obtain a faster demixing of the concentrated part obtained in step (b), to obtain a faster settling and collect a concentrated portion of chlorohydrin and chlorohydrin esters containing less water, and this, compared to a separation operation of step (c) carried out in the absence of the additive.

It has also been surprisingly found that the presence of the additive in the concentrated portion of chlorohydrin and chlorohydrin esters obtained in step (c) does not interfere with the downstream manufacturing processes of the process for producing chlorohydrin, as a method of making an epoxide by dehydrochlorinating chlorohydrin, for example.

The term "polyhydroxylated aliphatic hydrocarbon" refers to a hydrocarbon that contains at least two hydroxyl groups attached to two different saturated carbon atoms. The polyhydroxylated aliphatic hydrocarbon may contain, but is not limited to, from 2 to 60 carbon atoms.

Each of the carbons of a polyhydroxylated aliphatic hydrocarbon bearing the functional hydroxyl (OH) group can not have more than one OH group, and must be of sp3 hybridization. The carbon atom carrying the OH group may be primary, secondary or tertiary. The polyhydroxylated aliphatic hydrocarbon used in the present invention must contain at least two sp3 hybridization carbon atoms carrying an OH group. The polyhydroxylated aliphatic hydrocarbon includes any hydrocarbon containing a vicinal diol (1,2-diol) or a vicinal triol (1,2,3-triol) including higher orders of these repeating units, vicinal or contiguous . The definition the polyhydroxylated aliphatic hydrocarbon also includes, for example, one or more 1,3-, 1,4-, 1,5- and 1,6-diol functional groups. The polyhydroxylated aliphatic hydrocarbon may also be a polymer such as polyvinyl alcohol. Geminated diols, for example, are excluded from this class of polyhydroxylated aliphatic hydrocarbons.

The polyhydroxylated aliphatic hydrocarbons may contain aromatic entities or hetero atoms including, for example, hetero atoms of the halogen, sulfur, phosphorus, nitrogen, oxygen, silicon and boron type, and mixtures thereof. Polyhydroxylated aliphatic hydrocarbons for use in the present invention include, for example, 1,2-ethanediol (ethylene glycol), 1,2-propanediol (propylene glycol), 1,3-propanediol, 1-chloro-2, 3- propanediol (chloropropanediol), 2-chloro-1,3-propanediol (chloropropanediol), 1,4-butanediol, 1,5-pentanediol, cyclohexanediols, 1,2-butanediol, cyclohexanedimethanol, 1,2,3-propanetriol (also known as "glycerol" or "glycerin"), and mixtures thereof. Preferably, the polyhydroxylated aliphatic hydrocarbon used in the present invention includes, for example, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, chloropropanediol and 1,2,3-propanetriol, and mixtures of at least two of them. More preferably, the polyhydroxylated aliphatic hydrocarbon used in the present invention includes, for example, 1,2-ethanediol, 1,2-propanediol, chloropropanediol and 1,2,3-propanetriol, and mixtures thereof. least two of them. 1,2,3-propanetriol or glycerol is the most preferred. The esters of the polyhydroxylated aliphatic hydrocarbon may be present in the polyhydroxylated aliphatic hydrocarbon and / or may be produced in the process for the manufacture of chlorohydrin and / or may be manufactured prior to the process for producing the chlorohydrin. Examples of polyhydroxylated aliphatic hydrocarbon esters include ethylene glycol monoacetate, propanediol monoacetates, glycerol monoacetates, glycerol monostearates, glycerol diacetates, and mixtures thereof.

The term "chlorohydrin" is used here to describe a compound containing at least one hydroxyl group and at least one chlorine atom attached to different saturated carbon atoms. A chlorohydrin which contains at least two hydroxyl groups is also a polyhydroxylated aliphatic hydrocarbon. So, the starting material and the product of the Each reaction may be chlorohydrins. In this case, the "produced" chlorohydrin is more chlorinated than the starting chlorohydrin, that is to say that it has more chlorine atoms and fewer hydroxyl groups than the starting chlorohydrin. Preferred chlorohydrins are chloroethanol, chloropropanol, chloropropanediol, dichloropropanol and mixtures of at least two of them. Dichloropropanol is particularly preferred. More particularly preferred chlorohydrins are 2-chloroethanol, 1-chloropropan-2-ol, 2-chloropropane-1-ol, 1-chloropropane-2,3-diol, 2-chloropropane-1,3-diol. 1,3-dichloropropan-2-ol, 2,3-dichloropropan-1-ol and mixtures of at least two of them.

The term "epoxide" is used herein to describe a compound having at least one oxygen bridged on a carbon-carbon bond. Generally the carbon atoms of the carbon-carbon bond are adjacent and the compound may contain other atoms than carbon and oxygen atoms, such as hydrogen atoms and halogens. Preferred epoxides are ethylene oxide, propylene oxide, glycidol, epichlorohydrin and mixtures of at least two of them.

The polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, in the process according to the invention can be obtained starting from fossil raw materials or starting from renewable raw materials, preferably from renewable raw materials.

Fossil raw materials are understood to mean materials from the processing of petrochemical natural resources, for example, petroleum, natural gas, and coal. Of these materials, organic compounds having 2 and 3 carbon atoms are preferred. When the polyhydroxylated aliphatic hydrocarbon is glycerol, allyl chloride, allyl alcohol and "synthetic" glycerol are particularly preferred. By "synthetic" glycerol is meant a glycerol generally obtained from petrochemical resources. When the polyhydroxylated aliphatic hydrocarbon is ethylene glycol, ethylene and "synthetic" ethylene glycol are particularly preferred. By "synthetic" ethylene glycol is meant an ethylene glycol generally obtained from petrochemical resources. When the polyhydroxylated aliphatic hydrocarbon is propylene glycol, propylene and "synthetic" propylene glycol are particularly preferred. By "synthetic" propylene glycol is meant designate a propylene glycol generally obtained from petrochemical resources.

Renewable raw materials are defined as materials derived from the treatment of renewable natural resources. Among these materials, "natural" ethylene glycol, "natural" propylene glycol and "natural" glycerol are preferred. For example, "natural" ethylene glycol, propylene glycol and glycerol are obtained by sugar conversion via thermochemical processes, which sugars can be obtained from biomass, as described in Industrial Bioproducts: Today and Tomorrow, Energetics. , Incorporated for the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Office of the Biomass Program, July 2003, pages 49, 52 to 56 ". One of these processes is, for example, the catalytic hydrogenolysis of sorbitol obtained by thermochemical conversion of glucose. Another method is for example the catalytic hydrogenolysis of xylitol obtained by hydrogenation of xylose. The xylose can for example be obtained by hydrolysis of the hemicellulose contained in the corn fibers. By "natural glycerol" or "glycerol obtained from renewable raw materials" is meant in particular glycerol obtained during the manufacture of biodiesel or glycerol obtained during transformations of fats or oils of plant or animal origin in general such as saponification, trans-esterification or hydrolysis reactions.

Among the oils that can be used to make natural glycerol are all common oils, such as palm, palm kernel, copra, babassu, old or new rapeseed, sunflower, maize, castor oil and cotton oils. , peanut, soybean, flax and crambe oils and all oils derived for example from sunflower or rapeseed plants obtained by genetic modification or hybridization.

You can even use used cooking oils, various animal oils, such as fish oils, tallow, lard and even rendering fats.

Among the oils used, it is also possible to indicate partially modified oils, for example by polymerization or oligomerization, for example the "standolies" of linseed oil, sunflower oil and blown vegetable oils. A particularly suitable glycerol can be obtained during the processing of animal fats. Another particularly suitable glycerol can be obtained during the manufacture of biodiesel. A third particularly suitable glycerol can be obtained during the transformation of fats or oils, animal or vegetable by trans-esterification in the presence of a heterogeneous catalyst, as described in documents FR 2752242, FR 2869612 and FR More specifically, the heterogeneous catalyst is chosen from mixed oxides of aluminum and zinc, mixed oxides of zinc and titanium, mixed oxides of zinc, titanium and aluminum, and mixed oxides of bismuth and of aluminum, and the heterogeneous catalyst is implemented in the form of a fixed bed. The latter process may be a biodiesel manufacturing process.

In the process for producing a chlorohydrin according to the invention, the polyhydroxylated aliphatic hydrocarbon may be as described in the patent application "Process for preparing chlorohydrin by conversion of polyhydroxylated aliphatic hydrocarbons" deposited in the name of SOLVAY SA the same day as the present application, the content of which is hereby incorporated by reference.

Particular mention is made of a process for producing a chlorohydrin in which a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture thereof, of which the total content of expressed metals, is reacted. in the form of elements is greater than or equal to 0.1 μg / kg and less than or equal to 1000 mg / kg, with a chlorinating agent.

In the process according to the invention, it is preferred to use glycerol obtained from renewable raw materials. In the process according to the invention, the decantation operation leads to obtaining at least two condensed phases, preferably liquid phases. The concentrated portion of chlorohydrin and chlorohydrin esters and which contains less than 40% by weight of water is preferably a liquid phase.

In the process according to the invention, the decantation operation leads, particularly preferably, to obtaining two liquid phases. The phase that corresponds to the concentrated portion of chlorohydrin and chlorohydrin esters will be called organic phase. The phase that corresponds to the other portion will be called the aqueous phase.

The weight ratio of the settled phases varies according to the nature of the chlorinating agent used and the content of chlorinating agent in the concentrated portion of water, chlorohydrin and chlorohydrin esters. The percentage of the mass of the organic phase in the total mass of organic phase and aqueous phase is generally greater than or equal to 1, often greater than or equal to 10, frequently greater than or equal to 20 and in particular greater than or equal to 40. This ratio is generally less than or equal to 99, often greater than or equal to 90, frequently less than or equal to 80 and in particular greater than or equal to 60.

The additive present in step (c) may be an acid, a salt or a mixture of both. The acid and the salt can be organic or inorganic. It is preferred to use an acid or an inorganic salt. In a first embodiment of the process according to the invention, an inorganic acid is used. The latter may be selected from hydrogen halides, sulfuric, sulfurous, sulfhydric, nitric, nitrous, phosphoric, phosphorous, perchloric, chloric, chlorous, hypochlorous, carbonic, boric, and mixtures thereof. It is preferred to use hydrogen halides and in particular hydrogen chloride. When the acid is hydrogen chloride, it can be used in gaseous, liquid or aqueous or organic solutions. It is preferred to use it in gaseous form or aqueous solutions.

The acid content in the fraction of the concentrated part separated in step (b) and subjected to the decantation operation is generally greater than or equal to 0.01 g / kg, often greater than or equal to 0.3 g / kg. kg, frequently greater than or equal to 3 g / kg and in particular greater than or equal to 250 g / kg. This content is generally less than or equal to 110 g / kg, frequently less than or equal to 80 g / kg and in particular less than or equal to 65 g / kg. The acid contents in the aqueous and organic phases decanted in step (c) can be easily deduced from the ternary diagrams of compositions of the chlorohydrin-water-acid mixtures. Such a ternary diagram for the 1,3-dichloropropanol-water-hydrogen chloride mixture can be found in Gibson's G.P., The Preparation, Properties, and uses of glycerol derivatives. Part III. The chlorohydrins, pages 970 to 975.

The acid content in the aqueous phase decanted in step (c) is generally greater than or equal to 30 g / kg, often greater than or equal to 50 g / kg, frequently greater than or equal to 75 g / kg, and in particular greater than or equal to 100 g / kg. This content is generally less than or equal to 170 g / kg, frequently less than or equal to 150 g / kg and in particular less than or equal to 130 g / kg. In a first variant of the first embodiment of the process according to the invention, the acid is present in the concentrated portion of water, chlorohydrin and chlorohydrin esters separated in step (b).

In a second variant of the first embodiment of the process according to the invention, the acid is present in the concentrated portion of water, chlorohydrin and chlorohydrin esters separated in step (b) and added thereto. before subjecting this concentrated portion to the settling operation of step (c).

In a third variant of the first embodiment of the process according to the invention, the acid is present in the concentrated portion of water, chlorohydrin and chlorohydrin esters separated in step (b) and an additional amount is added thereto. before subjecting this concentrated portion to the settling operation of step (c).

In a second embodiment of the process according to the invention, an inorganic salt is used, preferably a metal salt. The latter may be selected from halides, sulphates, hydrogen sulphates, sulphites, hydrogen sulphites, sulphides, hydrogen sulphides, nitrates, nitrites, phosphates, hydrogen phosphates, phosphites, hydrogen phosphites, perchlorates, chlorates. metal hypochlorites, carbonates, hydrogencarbonates, percarbonates, borates and perborates, and mixtures thereof. It is preferred to use alkali and / or alkaline earth salts. The alkali and / or alkaline earth metal halides and in particular sodium chloride are preferred. The salts can be used in solid form or aqueous or organic solutions. It is preferred to use them as aqueous solutions.

In a first variant of the second embodiment, salts already formed in step (c) of the process according to the invention are added.

In a second variant of the second embodiment, the salts may also be generated in situ by reaction between an acid present in the fraction of the part obtained in step (b) and a basic compound. The basic compound may be an oxide, a hydroxide, a carbonate, a hydrogencarbonate, or a mixture of at least two of them. The oxides, hydroxides, carbonates and hydrogenocarbons of alkali and alkaline earth metals, and mixtures thereof, are preferred. Of the alkali and alkaline earth metals, sodium, potassium and calcium are preferred. The benefits of this second variant are the coupling between the neutralization of the acid and the supply of salt necessary for decantation.

The salt content in the aqueous phase decanted in step (c) is generally greater than or equal to 0.4 g / kg, often greater than or equal to 5 g / kg, frequently greater than or equal to 30 g / kg, and greater than or equal to 65 g / kg. This content is generally less than or equal to 450 g / kg, often less than or equal to 350 g / kg, frequently less than or equal to

200 g / kg and in particular less than or equal to 100 g / kg.

In this second embodiment of the process according to the invention, the salt is not present in the concentrated portion of water, chlorohydrin and chlorohydrin esters separated in step (b) and is added before submit this part the decanting operation of step (c).

In a third embodiment of the process according to the invention, a mixture of an inorganic salt and an inorganic acid as described above is used. Acids and salts having the same anion are preferred. Among these anions, the halides are particularly preferred and the chloride is very particularly preferred.

In a first variant of this third embodiment of the process according to the invention, the salt and the acid are not present in the concentrated portion of water, chlorohydrin and chlorohydrin esters separated in step (b) and they are added before subjecting this concentrated portion to the decanting operation of step (c).

In a second variant of this third embodiment of the process according to the invention, the salt is not present in the concentrated portion of water, chlorohydrin and chlorohydrin esters separated in step (b) and it is added before subjecting this concentrated portion to the decantation process of step (c) and the acid is present in the concentrated water and chlorohydrin portion separated in step (b).

In a third variant of this third embodiment of the process according to the invention, the salt is not present in the concentrated portion of water, chlorohydrin and chlorohydrin esters separated in step (b) and it is added before subjecting this concentrated portion to the decantation process of step (c) and the acid is present in the concentrated portion of water, chlorohydrin and chlorohydrin esters separated in step (b) and adds an additional amount before subjecting this concentrated portion to the settling operation of step (c). The ratio between the number of moles of chlorohydrin esters and the sum of the number of moles of chlorohydrin esters and the number of moles of chlorohydrin is generally greater than or equal to 0.2, preferably less than or equal to 0.1. and more preferably less than or equal to 0.01. In the process according to the invention, the decantation operation can be carried out under the effect of gravity or under the effect of a centrifugal force. It is preferred to perform this operation under the effect of gravity.

In the process according to the invention, the decantation operation is carried out at a temperature generally less than or equal to 100 ^° C., often less than or equal to 80 ^° C., frequently less than or equal to 70 ^° C. and in particular less than or equal to at 50 ^° C. This temperature is generally greater than or equal to 4 ^° C. and often greater than or equal to 10 ^° C.

In the process according to the invention, the settling time is generally less than or equal to 120 min, preferably less than or equal to 90 min and particularly preferably less than or equal to 60 min. This time is defined as the volume of the decanter relative to the volume flow of liquid fed to the decanter.

The water content in the concentrated portion of chlorohydrin and chlorohydrin esters can be readily deduced from the ternary diagrams of compositions of the chlorohydrin-water-acid mixtures. Such a ternary diagram for the 1,3-dichloropropanol-water-hydrogen chloride mixture can be found in Gibson's G.P., The Preparation, Properties, and uses of glycerol derivatives. Part III. The chlorohydrins., Pages 970 to 975.

The water content in the fraction of the concentrated portion of chlorohydrin and chlorohydrin esters obtained in step (c) is preferably less than or equal to 20% by weight and often less than or equal to 10% by weight, frequently lower than or equal to 5% by weight, in particular less than or equal to 1.5% by weight and all specifically less than or equal to 1% by weight.

In the process for preparing a chlorohydrin according to the invention, the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, may be a crude product or a purified product, such as specifically disclosed in SOLVAY SA application WO 2005/054167, page 2, line 8, to page 4, line 2.

In the process for preparing a chlorohydrin according to the invention, the polyhydroxylated aliphatic hydrocarbon may be a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture of them, the alkali and / or alkaline earth metal content may be less than or equal to 5 g / kg as described in the application entitled "Process for the manufacture of a chlorohydrin by chlorination of an aliphatic hydrocarbon polyhydroxylated "deposited in the name of SOLVAY SA the same day as the present application, the contents of which are hereby incorporated by reference. The alkali metals can be selected from lithium, sodium, potassium, rubidium and cesium and the alkaline earth metals can be selected from magnesium, calcium, strontium and barium. In the process according to the invention, the content of alkali and / or alkaline-earth metals of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is less than or equal to at 5 g / kg, often less than or equal to 1 g / kg, more particularly less than or equal to 0.5 g / kg and in some cases less than or equal to 0.01 g / kg. The content of alkaline and / or alkaline earth metals of glycerol is generally greater than or equal to 0.1 μg / kg.

In the process according to the invention, the alkali metals are generally lithium, sodium, potassium and cesium, often sodium and potassium, and frequently sodium.

In the process for producing a chlorohydrin according to the invention, the lithium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to at 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg. In the process according to the invention, the sodium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg.

In the process according to the invention, the potassium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg. In the process according to the invention, the rubidium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg.

In the process according to the invention, the cesium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg.

In the process according to the invention, the alkaline-earth elements are generally magnesium, calcium, strontium and barium, often magnesium and calcium and frequently calcium.

In the process according to the invention, the magnesium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg.

In the process according to the invention, the calcium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg.

In the process according to the invention, the strontium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg.

In the process according to the invention, the barium content of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, is generally less than or equal to 1 g / kg, often less than or equal to 0.1 g / kg and more particularly less than or equal to 2 mg / kg. This content is generally greater than or equal to 0.1 μg / kg.

In the process according to the invention, the alkali and / or alkaline earth metals are generally present in the form of salts, frequently in the form of chlorides, sulphates and mixtures thereof. Sodium chloride is most often encountered.

In the process for preparing a chlorohydrin according to the invention, the chlorinating agent may be as described in SOLVAY SA application WO 2005/054167, page 4, line 25, to page 6, line 2 .

In the process for preparing a chlorohydrin according to the invention, the chlorinating agent may be hydrogen chloride may be as described in the application WO 2005/054167 SOLVAY SA, page 4, line 30, on page 6, line 2. Particular mention is made of a chlorinating agent which may be aqueous hydrochloric acid or preferably anhydrous hydrogen chloride. Hydrogen chloride may be derived from a process for pyrolysis of chlorinated organic compounds such as vinyl chloride production, a process for the manufacture of 4,4-methylenediphenyl diisocyanate (MDI) or toluene diisocyanate ( TDI), metal stripping processes or a reaction between an inorganic acid such as sulfuric or phosphoric acid and a metal chloride such as sodium chloride, potassium chloride or calcium chloride.

In an advantageous embodiment of the method for producing a chlorohydrin according to the invention, the chlorinating agent is gaseous hydrogen chloride or an aqueous solution of hydrogen chloride or a combination of both.

In the process for preparing a chlorohydrin according to the invention, the hydrogen chloride may be an aqueous solution of hydrogen chloride or preferably anhydrous hydrogen chloride, originating from a plant for the production of chloride of hydrogen. allyl and / or manufacture of chloromethanes and / or chlorinolysis and / or high temperature oxidation of chlorinated compounds as described in the application entitled "Process for producing a chlorohydrin by reaction between a polyhydroxylated aliphatic hydrocarbon and a chlorinating agent "filed on behalf of SOLVAY SA on the same day as the present application, the contents of which are hereby incorporated by reference. Particular mention is made of a process for producing a chlorohydrin from a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture of them, and a chlorinating agent, the latter containing at least one of the following compounds: nitrogen, oxygen, hydrogen, chlorine, an organic hydrocarbon compound, a halogenated organic compound, an oxygenated organic compound and a metal.

Particular mention is made of an organic hydrocarbon compound which is selected from aromatic hydrocarbons, saturated or unsaturated aliphatic and mixtures thereof.

Particular mention is made of an unsaturated aliphatic hydrocarbon which is selected from acetylene, ethylene, propylene, butene, propadiene, methylacetylene, and mixtures thereof, of a saturated aliphatic hydrocarbon which is selected from methane , ethane, propane, butane, and mixtures thereof, and an aromatic hydrocarbon which is benzene.

Particular mention is made of a halogenated organic compound which is a chlorinated organic compound chosen from chloromethanes, chloroethanes, chloropropanes, chlorobutanes, vinyl chloride, vinylidene chloride, monochloropropenes, perchlorethylene, trichlorethylene, chlorobutadiene, chlorobenzenes and mixtures thereof.

Particular mention is made of a halogenated organic compound which is a fluorinated organic compound selected from fluoromethanes, fluoroethanes, vinyl fluoride, vinylidene fluoride, and mixtures thereof.

Particular mention is made of an oxygenated organic compound which is chosen from alcohols, chloroalcohols, chloroethers and their mixtures

Particular mention is made of a metal selected from alkali metals, alkaline earth metals, iron, nickel, copper, lead, arsenic, cobalt, titanium, cadmium, antimony, mercury, zinc, selenium, aluminum, bismuth, and mixtures thereof.Mention is more particularly made of a process in which the chlorinating agent is derived at least partially from a process for the production of chlorine. allyl and / or a process for producing chloromethanes and / or a chlorinolysis process and / or a process for the oxidation of chlorinated compounds at a temperature greater than or equal to 800 ^° C. In one embodiment particularly advantageous in the process for producing a chlorohydrin according to the invention, hydrogen chloride is a aqueous solution of hydrogen chloride and does not include gaseous hydrogen chloride.

In the process for the preparation of a chlorohydrin according to the invention, the reaction between the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, and the chlorinating agent can be carried out in a reactor as described in SOLVAY SA application WO 2005/054167, on page 6, lines 3 to 23.

Particular mention is made of an installation made of or covered with resistant materials under the conditions of the reaction with the chlorinating agents, in particular with hydrogen chloride. Mention is more particularly made of an installation made of enamelled steel or tantalum. In the process for the preparation of a chlorohydrin according to the invention, the reaction between the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, and the chlorinating agent can be carried out in equipment, made of or covered with chlorine-resistant materials, as described in the application entitled "Process for the manufacture of a chlorohydrin in corrosion-resistant equipment" filed on behalf of SOLVAY SA the same the present application, the contents of which are hereby incorporated by reference. Particular mention is made of a process for the manufacture of a chlorohydrin comprising a step in which a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof is subjected to a reaction with a chlorinating agent containing hydrogen chloride and at least one other step performed in equipment, made of or coated with chlorinating agent resistant materials, under the conditions of carrying out this step. Mention is more particularly made of metallic materials such as enamelled steel, gold and tantalum and non-metallic materials such as high density polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene , perfluoroalkoxyalkanes and poly (perfluoropropylvinylether), polysulfones and polysulfides, graphite and impregnated graphite.

In the process for the preparation of a chlorohydrin according to the invention, the reaction between the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, and the chlorinating agent can be carried out in a reaction medium, as described in the application entitled "Continuous process for the manufacture of chlorohydrins" filed in the name of SOLVAY SA the same day as the present application, the contents of which are hereby incorporated by reference.

Particular mention is made of a continuous process for the production of chlorohydrin in which a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture of them is reacted with a chlorinating agent and an organic acid. in a liquid reaction medium whose composition in the stationary state comprises polyhydroxylated aliphatic hydrocarbon and esters of the polyhydroxylated aliphatic hydrocarbon whose sum of the contents expressed in moles of polyhydroxylated aliphatic hydrocarbon is greater than 1, 1 mol% and less than or equal to 30 mol%, the percentage being related to the organic part of the liquid reaction medium.

The organic part of the liquid reaction medium consists of all the organic compounds of the liquid reaction medium, that is to say compounds whose molecule contains at least 1 carbon atom.

In the process for preparing a chlorohydrin according to the invention, the reaction between the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, and the chlorinating agent can be carried out in the presence of a catalyst as described in SOLVAY SA application WO 2005/054167, page 6, line 28, to page 8, line 5.

Particular mention is made of a catalyst based on a carboxylic acid or on a carboxylic acid derivative having an atmospheric boiling point greater than or equal to 200 ^° C., in particular adipic acid and derivatives of adipic acid. . In the process for preparing a chlorohydrin according to the invention, the reaction between the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, and the chlorinating agent can be carried out at a catalyst concentration, a temperature, a pressure and for residence times as described in SOLVAY SA application WO 2005/054167, page 8, line 6 to page 10, line 10.

Particular mention is made of a temperature of at least 20 ^° C. and at most 160 ^° C., a pressure of at least 0.3 bar and a maximum of 100 bar, and a time stay of not less than 1 hour and not more than 50 hours.

In the process for preparing a chlorohydrin according to the invention, the reaction between the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, and the chlorinating agent may be carried out in the presence of a solvent as described in the application WO 2005/054167 of SOLVAY SA, on page 11, lines 12 to 36.

Particular mention is made of an organic solvent such as a chlorinated organic solvent, an alcohol, a ketone, an ester or an ether, a non-aqueous solvent miscible with the polyhydroxylated aliphatic hydrocarbon such as chloroethanol, chloropropanol and chloropropanediol. , dichloropropanol, dioxane, phenol, cresol, and mixtures of chloropropanediol and dichloropropanol, or heavy products of the reaction such as oligomers of the at least partially chlorinated and / or esterified polyhydroxylated aliphatic hydrocarbon.

In the process for preparing a chlorohydrin according to the invention, the reaction between the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, and the chlorinating agent can be carried out in the presence of a liquid phase comprising heavy compounds other than the polyhydroxylated aliphatic hydrocarbon, as described in the application entitled "Process for the manufacture of a chlorohydrin in a liquid phase" deposited in the name of SOLVAY SA on the same day as the present application, the content of which is hereby incorporated by reference.

Particular mention is made of a process for producing a chlorohydrin, wherein a polyhydroxylated aliphatic hydrocarbon, a polyhydroxylated aliphatic hydrocarbon ester, or a mixture thereof is subjected to a reaction with a chlorinating agent. in the presence of a liquid phase comprising heavy compounds other than the polyhydroxylated aliphatic hydrocarbon and whose boiling point at a pressure of 1 bar absolute is at least 15 ⁰ C higher than the boiling point of chlorohydrin under a pressure of 1 bar absolute.

In the process for preparing a chlorohydrin according to the invention, the reaction between the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, and the chlorinating agent is preferentially carried out in a liquid reaction medium. The liquid reaction medium may be mono- or multiphasic.

The liquid reaction medium consists of all the dissolved or dispersed solid compounds, dissolved or dispersed liquids and gaseous dissolved or dispersed, at the reaction temperature. The reaction medium comprises the reactants, the catalyst, the solvent, the impurities present in the reagents, in the solvent and in the catalyst, the reaction intermediates, the products and the by-products of the reaction.

By reagents is meant the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester and the chlorinating agent.

Among the impurities present in the polyhydroxylated aliphatic hydrocarbon, mention may be made of carboxylic acids, carboxylic acid salts, fatty acid esters with polyhydroxylated aliphatic hydrocarbon, esters of fatty acids with the alcohols used. during the trans-esterification, inorganic salts such as chlorides and sulphates alkali or alkaline earth.

When the polyhydroxylated aliphatic hydrocarbon is glycerol, mention may be made, among the impurities of glycerol, of carboxylic acids, carboxylic acid salts, fatty acid esters such as mono-, di- and triglycerides, esters of fatty acids with the alcohols used in transesterification; inorganic salts such as alkali or alkaline earth chlorides and sulphates.

Among the reaction intermediates, mention may be made of the monochlorohydrins of the polyhydroxylated aliphatic hydrocarbon and their esters and / or polyesters, the esters and / or polyesters of the polyhydroxylated aliphatic hydrocarbon and the esters of the polychlorohydrins.

When the chlorohydrin is dichloropropanol, mention may be made, among the reaction intermediates, of glycerol monochlorohydrin and its esters and / or polyesters, esters and / or polyesters of glycerol and esters of dichloropropanol. The polyhydroxylated aliphatic hydrocarbon ester may therefore be, depending on the case, a reagent, an impurity of the polyhydroxylated aliphatic hydrocarbon or a reaction intermediate.

By products of the reaction is meant chlorohydrin and water. The water may be the water formed in the chlorination reaction and / or the water introduced into the process, for example via the polyhydroxylated aliphatic hydrocarbon and / or the chlorinating agent, as described in the application WO 2005/054167 of SOLVAY SA, on page 2, lines 22 to 28, on page 3, lines 20 to 25, on page 5, lines 7 to 31 and on page 12, lines 14 to 19.

Among the by-products include, for example, partially chlorinated and / or esterified polyhydroxylated aliphatic hydrocarbon oligomers. When the polyhydroxylated aliphatic hydrocarbon is glycerol, among the by-products, mention may be made, for example, of partially chlorinated and / or esterified glycerol oligomers.

The reaction intermediates and by-products may be formed in the various process steps such as, for example, during the chlorohydrin manufacturing step and during the chlorohydrin separation steps.

The liquid reaction medium may thus contain the polyhydroxylated aliphatic hydrocarbon, the dissolved or dispersed chlorination agent in the form of bubbles, the catalyst, the solvent, the impurities present in the reactants, the solvent and the catalyst, such as dissolved salts. or solids for example, the solvent, the catalyst, the reaction intermediates, the products and the by-products of the reaction.

The steps (a), (b) and (c) of the process for preparing a chlorohydrin according to the invention can be carried out independently in batch mode or in continuous mode. The continuous mode for the 3 steps is particularly preferred.

In the process for the preparation of a chlorohydrin according to the invention, the chlorination reaction of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of them, can be carried out in the presence an organic acid. The organic acid may be a product from the process for producing the polyhydroxylated aliphatic hydrocarbon or a product not from this process. In the latter case, it may be an organic acid used to catalyze the reaction between the polyhydroxylated aliphatic hydrocarbon and the chlorinating agent. The organic acid may also be a mixture of organic acid from the process for producing the polyhydroxylated aliphatic hydrocarbon and an organic acid not originating from the process for producing the polyhydroxylated aliphatic hydrocarbon.

In the process according to the invention, the esters of the polyhydroxylated aliphatic hydrocarbon can come from the reaction between the polyhydroxylated aliphatic hydrocarbon and the organic acid, before, during or in the steps which follow the reaction with the chlorinating agent. . The organic acid is as defined above.

In the process according to the invention, the separation of the chlorohydrin and the other compounds from the reaction medium can be carried out according to the modes as described in the application WO 2005/054167 of SOLVAY SA, of page 12, line 1, page 16, line 35 and page 18, lines 6 to 13. These other compounds are those mentioned above and include the reagents not consumed, the impurities present in the reagents, the catalyst, the solvent, reaction intermediates, water and by-products of the reaction. Particular mention is made of separation by azeotropic distillation of a water / chlorohydrin / chlorinating agent mixture under conditions which minimize losses of chlorinating agent followed by separation of the chlorohydrin by decantation.

In the process for the preparation of a chlorohydrin according to the invention, the separation of the chlorohydrin and the other compounds from the reaction medium may be carried out according to the methods described in the patent application EP 05104321.4 filed in the name of SOLVAY SA on 20/05/2005 whose content is hereby incorporated by reference. Particular mention is made of a separation mode comprising at least one separation operation for removing the salt from the liquid phase.

Particular mention is made of a process for producing a chlorohydrin by reaction between a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture of them, and a chlorinating agent in which the hydrocarbon Polyhydroxylated aliphatic acid, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof, used contains at least one solid or dissolved metal salt, the process comprising a separation process for removing a portion of the metal salt. Mention is more particularly made of a process for producing a chlorohydrin by reaction between a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture of them, and a chlorinating agent in which polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof, used contains at least one sodium and / or potassium chloride and / or sulfate and wherein the separation operation for removing some of the metal salt is a filtration operation. Particular mention is also made of a process for producing a chlorohydrin in which (a) a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof is subjected to a reaction with a chlorinating agent in a reaction medium, (b) continuously or periodically removing a fraction of the reaction medium containing at least water and chlorohydrin, (c) at least one part of the fraction obtained in step (b) is introduced into a distillation step and (d) the reflux ratio of the distillation step is controlled by supplying water to said distillation step. Particular mention is made of a process for producing a chlorohydrin in which (a) a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof is subjected to a reaction with hydrogen chloride in a reaction medium, (b) a fraction of the reaction medium containing at least water and the chlorohydrin is withdrawn continuously or periodically, (c) at least part of the fraction obtained in step ( b) is introduced into a distillation step, wherein the ratio between the hydrogen chloride concentration and the water concentration in the fraction introduced into the distillation step is smaller than the ratio of hydrogen chloride concentrations / water in the azeotropic hydrogen chloride / water binary composition at the distillation temperature and pressure.

In the process for the production of a chlorohydrin according to the invention, the separation of the chlorohydrin and the other compounds from the reaction medium of chlorination of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of between them, may be carried out according to the modes as described in the application entitled "Process for the manufacture of a chlorohydrin" deposited in the name of SOLVAY SA, the same day as the present application, and the contents of which are hereby incorporated by reference .

Particular mention is made of a process for producing a chlorohydrin comprising the following steps: (a) reacting a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture thereof, with a chlorination and an organic acid to obtain a mixture containing chlorohydrin and chlorohydrin esters, (b) subjecting at least a portion of the mixture obtained in step (a) to one or more treatments in subsequent steps in step (a) and (c), polyhydroxylated aliphatic hydrocarbon is added to at least one of the steps subsequent to step (a), so that it reacts at a temperature greater than or equal to 20 ^° C., with the chlorohydrin esters so as to at least partially form esters of the polyhydroxylated aliphatic hydrocarbon. Mention is more particularly made of a process in which the polyhydroxylated aliphatic hydrocarbon is glycerol and the chlorohydrin is dichloropropanol. In the process for the production of a chlorohydrin according to the invention, the separation of the chlorohydrin and the other compounds from the reaction medium of chlorination of the polyhydroxylated aliphatic hydrocarbon, of the polyhydroxylated aliphatic hydrocarbon ester, or of the mixture of between them, can be carried out according to the modes as described in the application entitled "Process for the manufacture of a chlorohydrin starting from a polyhydroxylated aliphatic hydrocarbon" deposited in the name of SOLVAY SA the same day as the present application, and whose content is hereby incorporated by reference.

Particular mention is made of a process for producing chlorohydrin by reaction between a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture of them, and a chlorinating agent in a reactor which is fed with one or more liquid streams containing less than 50% by weight of the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, based on the weight of all the liquid streams introduced into the polyhydroxylated aliphatic hydrocarbon, the reactor.

More particular mention is made of a process comprising the following steps: (a) A polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture of them, is reacted with a chlorinating agent in a manner such that to obtain at least one medium containing chlorohydrin, water and chlorinating agent, (b) at least a fraction of the medium formed in step (a) and (c) is removed. fraction taken in step (b) to a distillation and / or stripping operation in which polyhydroxylated aliphatic hydrocarbon is added so as to separate from the fraction taken in step (b) a mixture containing water and chlorohydrin having a reduced content of chlorinating agent compared to that of the fraction taken in step (b).

In the process for the production of a chlorohydrin according to the invention, the separation and the treatment of the other compounds of the reaction medium can be carried out according to modes as described in the application entitled "Process for the production of a chlorohydrin by chlorination of a polyhydroxylated aliphatic hydrocarbon deposited in the name of SOLVAY SA the same day as the present application. A preferred treatment is to subject a fraction of the by-products of the reaction to high temperature oxidation. Particular mention is made of a process for the manufacture of a chlorohydrin comprising the following steps: (a) reacting a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydric aliphatic hydrocarbon hydroxyl, or a mixture thereof, the content of alkali metals and / or alkaline earth is less than or equal to 5 g / kg, an oxidizing agent and an organic acid so as to obtain a mixture containing at least the chlorohydrin and by-products, (b) subjecting at least a portion of the mixture obtained in step (a) to one or more treatments in steps subsequent to step (a) and (c) at least one of The steps subsequent to step (a) consist of an oxidation at a temperature greater than or equal to 800 ^° C. A more particular mention is made of a process in which in the subsequent step, a part of the mixture obtained is extracted from the mixture. step (a) and this part is subjected to oxidation at a temperature greater than or equal to 800 ^° C. during the sampling. Particular mention is also made of a process in which the treatment of step (b) is a separation operation chosen from among the operations of decantation, filtration, centrifugation, extraction, washing, evaporation, stripping, distillation, adsorption or combinations of at least two of them. In the process according to the invention, when the chlorohydrin is chloropropanol, it is generally used in the form of a mixture of compounds comprising the isomers of 1-chloropropan-2-ol and 2-chloropropane-1. ol. This mixture generally contains more than 1% by weight of the two isomers, preferably more than 5% by weight and more particularly more than 50%. The mixture usually contains less than 99.9% by weight of the two isomers, preferably less than 95% by weight and most preferably less than 90% by weight. The other constituents of the mixture may be compounds derived from chloropropanol production processes, such as residual reagents, reaction by-products, solvents and in particular water.

The weight ratio between the isomers 1-chloropropan-2-ol and 2-chloropropane-1-ol is usually greater than or equal to 0.01, preferably greater than or equal to 0.4. This ratio is usually less than or equal to 99 and preferably less than or equal to 25. In the process according to the invention, when the chlorohydrin is chloroethanol, it is generally used in the form of a mixture of compounds. comprising the 2-chloroethanol isomer. This mixture generally contains more than 1% by weight of the isomer, preferably more than 5% by weight and especially more than 50%. The mixture usually contains less than 99.9% by weight of the isomer, preferably less than 95% by weight and most preferably less than 90% by weight. Others constituents of the mixture may be compounds from chloroethanol manufacturing processes, such as residual reagents, reaction by-products, solvents and especially water.

In the process according to the invention, when the chlorohydrin is chloropropanediol, it is generally used in the form of a mixture of compounds comprising the isomers of 1-chloropropane-2,3-diol and 2-chloropropane. -l, 3-diol. This mixture generally contains more than 1% by weight of the two isomers, preferably more than 5% by weight and more particularly more than 50%. The mixture usually contains less than 99.9% by weight of the two isomers, preferably less than 95% by weight and most preferably less than 90% by weight. The other constituents of the mixture may be compounds derived from chloropropanediol production processes, such as residual reagents, reaction by-products, solvents and in particular water. The mass ratio between the 1-chloropropane-2,3-diol isomers and

2-chloropropane-1,3-diol is usually greater than or equal to 0.01, preferably greater than or equal to 0.4. This ratio is usually less than or equal to 99 and preferably less than or equal to 25.

In the process according to the invention, when the chlorohydrin is dichloropropanol, it is generally used in the form of a mixture of compounds comprising the isomers of 1,3-dichloropropan-2-ol and , 3-dichloropropane-l-ol. This mixture generally contains more than 1% by weight of the two isomers, preferably more than 5% by weight and more particularly more than 50%. The mixture usually contains less than 99.9% by weight of the two isomers, preferably less than 95% by weight and most preferably less than 90% by weight. The other constituents of the mixture may be compounds from dichloropropanol production processes, such as residual reagents, reaction by-products, solvents and in particular water. The mass ratio between the 1,3-dichloropropan-2-ol isomers and

2,3-dichloropropan-1-ol is usually greater than or equal to 0.01, often greater than or equal to 0.4, frequently greater than or equal to 1.5, preferably greater than or equal to 3.0, so more preferably greater than or equal to 7.0 and most preferably greater than or equal to 20.0. This ratio is usually less than or equal to 99 and preferably less than or equal to 25. The chlorohydrin obtained in the process according to the invention may contain a high content of halogenated ketones, in particular chloroacetone, as described in the patent application FR 05.05120 of 20/05/2005 filed in the name of the Applicant, and whose content is hereby incorporated by reference. The content of halogenated ketone can be reduced by subjecting the chlorhdyrine obtained in the process according to the invention to azeotropic distillation in the presence of water or by subjecting the chlorohydrin to a dehydrochlorination treatment as described in this application, on page 4, line 1, on page 6, line 35.

Particular mention is made of a process for producing an epoxide in which halogenated ketones are formed as by-products and which comprises at least one treatment for removing at least a portion of the halogenated ketones formed. Mention is more particularly made of a process for producing an epoxide by dehydrochlorination of a chlorohydrin of which at least one fraction is produced by chlorination of a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture thereof, a dehydrochlorination treatment and azeotropic distillation treatment of a halogenated water-ketone mixture for removing at least a portion of the halogenated ketones formed and a method of manufacture epichlorohydrin in which the halogenated ketone formed is chloroacetone.

The chlorohydrin obtained in the process according to the invention can be subjected to a dehydrochlorination reaction to produce an epoxide as described in the patent applications WO 2005/054167 and FR 05.05120 filed in the name of SOLVAY SA The dehydrochlorination of the chlorohydrin can be carried out as described in the application entitled "Process for producing an epoxide from a polyhydroxylated aliphatic hydrocarbon and a chlorinating agent" deposited in the name of SOLVAY SA on the same day as the present application, and whose content is here incorporated by reference. Particular mention is made of a process for producing an epoxide in which a reaction medium resulting from the reaction between a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture of them, is subjected to and a chlorinating agent, the reaction medium containing at least 10 g of chlorohydrin per kg of reaction medium, to a subsequent chemical reaction without intermediate treatment. Mention is also made of manufacturing an epoxide comprising the following steps:

(a) A polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof is reacted with a chlorinating agent and an organic acid to form chlorohydrin and chlorohydrin in a reaction medium containing polyhydroxylated aliphatic hydrocarbon, polyhydroxylated aliphatic hydrocarbon ester, water, the chlorinating agent and the organic acid, the reaction medium containing at least 10 g of chlorohydrin per kg of reaction medium,

(b) at least one fraction of the reaction medium obtained in step (a), which fraction having the same composition as the reaction medium obtained in step (a), is subjected to one or more treatments in stages subsequent to step (a), (c) adding a basic compound to at least one of the steps subsequent to step (a) to react at least partially with the chlorohydrin, the chlorohydrin esters, the chlorination and the organic acid to form epoxide and salts.

The process for the preparation of the chlorohydrin according to the invention can be integrated into an overall scheme for producing an epoxide as described in the application entitled "Process for producing an epoxide from a chlorohydrin" deposited in the name of SOLVAY SA the same day as the present application, and the contents of which are hereby incorporated by reference.

Particular mention is made of a process for the production of an epoxide comprising at least one step of purifying the epoxide formed, the epoxide being at least partly produced by a process for the dehydrochlorination of a chlorohydrin, the latter being at least partly manufactured by a process for chlorinating a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture of them. When the epoxide is epichlorohydrin, the manufacture of the epoxide can be integrated into a process for the manufacture of epoxy resins.

In the process according to the invention, the polyhydroxylated aliphatic hydrocarbon is preferably glycerol and the chlorohydrin is preferably dichloropropanol. When the chlorohydrin is dichloropropanol, the process according to the invention can be followed by a production of epichlorohydrin by dehydrochlorination of dichloropropanol and epichlorohydrin can be used in the manufacture of epoxy resins.

Steps (b) and (c) of the process according to the invention also apply to a mixture containing chlorohydrin, chlorohydrin esters and water obtained by reactions other than the reaction between a polyaliphatic hydrocarbon. hydroxylated and a chlorinating agent, for example by hypochlorination of an olefin such as ethylene, propylene and allyl chloride or by chlorination of an alcohol, such as allyl alcohol for example.

Figure 1 shows a particular installation scheme used to implement the preparation method according to the invention.

A reactor (4) is fed continuously or in batch mode with a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture of them via the line (1) and into a catalyst via the line (2), the supply of chlorinating agent is carried out in continuous mode or in batch mode via line (3), a distillation column (6) is fed via line (5) with vapors produced in the reactor (4), a stream is withdrawn from the column (6) via the line (7) and is introduced into a condenser (8), the flow from the condenser is introduced via the line (9) into a decanter (10) in which aqueous and organic phases are separated. An additive may be introduced into the flow of the line (7) via the line (31) and / or in the stream of the line (9) via the line (32). A fraction of the separated aqueous phase is optionally recycled via line (11) to the top of the column to maintain reflux. Water is introduced into line 11 via line 12. The production of chlorohydrin is distributed between the organic phase withdrawn via line (14) and the aqueous phase withdrawn via line (13). The residue of the column (6) can be recycled to the reactor (4) via line (15). A fraction of the heavy products is withdrawn from the reactor (4) via the purge (16) and is introduced via line (17) into an evaporator (18) in which a partial evaporation operation is carried out for example by heating or by sweeping gaseous with nitrogen or water vapor, the gaseous phase containing most of the flow chlorinating agent (17) is recycled via line (19) to column (6) or via the line (20) to the reactor (4), a distillation or stripping column (22) is fed with the liquid phase from the stripping apparatus (18) via the line (21), the major part of the chlorohydrin is collected at the top of the column (22) via line (23). Optionally, the heavy by-products from the column (22) are sent via the line (24) into the filtration column (25) in which liquid and solid phases are separated, a fraction of the liquid phase is recycled via the line (26) to the reactor (4). The solid can be withdrawn from the filtration unit (25) via the line (27) in the form of a solid or a solution. Solvents may be added to the filtration unit (25) via lines (28) and (29) for washing and / or dissolving the solid and withdrawn via line (27). Optionally, a stream is withdrawn from the purge (16) and introduced via the line (30) into the filtration column (25). The stripping apparatus (18) and the distillation column (22) are then short-circuited.

The following examples intend to illustrate the invention without limiting it. Example 1 to 18 (in accordance with the invention)

In a separating funnel whose bottom consists of a graduated cylindrical tube, water, 1,3-dichloropropanol and aqueous solutions of hydrogen chloride (Examples 1 to 5) were thoroughly mixed, perchloric acid (Examples 6 to 10), sodium chloride (Examples 11 to 16) and calcium chloride (Examples 17 and 18), the concentrations of which are given respectively in Tables 1 to 4, for 15 minutes to 25 minutes. ⁰ C. stirring was stopped and the mixture was then allowed to settle. The height of the interface between the phases was measured over time. The zero time corresponds to the cessation of agitation. The time after which the height of the interface is constant to +/- 1 mm constitutes the duration of the decantation operation. In the organic phase, the contents of hydrogen chloride and perchloric acid are measured by acid-base titration, the content of sodium chloride and calcium chloride by silver titration or by Atomic Emission Spectrometry coupled to Plasma Induction. (ICP-AES) respectively according to whether the salt concentration is high or low and the water content by the Karl-Fisher method. The dichloropropanol content is calculated by difference. In the aqueous phase, the contents of hydrogen chloride and perchloric acid are measured by acid-base titration, the content of sodium chloride and calcium chloride by argentimetric titration and the content of dichloropropanol by vapor phase chromatography. The water content is calculated by difference. The settling times and compositions of the aqueous and organic phases are reported in Tables 1 to 4. Example 19 to 22 (in accordance with the invention)

The procedure of the preceding examples was repeated using 2,3-dichloropropan-1-ol and aqueous solutions of perchloric acid and sodium chloride, the concentrations of which are given in Tables 5 and 6. The times of decantation and the compositions of the aqueous and organic phases are reported in Tables 5 and 6.

Table 1

U)

O

Table 3

Table 5

U) K)

Claims

R E V E N D I C A T IO N S

1 - Process for preparing a chlorohydrin comprising the following steps:

(a) A polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof is reacted with a chlorinating agent to obtain a mixture containing chlorohydrin, chlorohydrin esters and the water

(b) at least a fraction of the mixture obtained in step (a) is subjected to a distillation and / or stripping treatment so as to obtain a concentrated portion of water, chlorohydrin and chlorohydrin esters.

(c) at least a fraction of the part obtained in step (b) is subjected to a separation operation in the presence of at least one additive so as to obtain a concentrated portion of chlorohydrin and of chlorohydrin esters and which contains less than 40% by weight of water.

2 - Process according to claim 1 wherein the concentrated portion of chlorohydrin and chlorohydrin esters of step (c) contains less than 15% by weight of water.

3 - Process according to claim 1 or 2 wherein the separation operation is a decantation.

4 - Process according to claim 3 wherein the decantation is carried out under the action of gravity.

5 - Process according to any one of claims 1 to 4 wherein the additive present in step (c) contains an inorganic acid, an inorganic salt or a mixture of both.

6 - Process according to claim 5 wherein the acid is selected from hydrogen halides, sulfuric, sulfurous, sulfhydric, nitric, nitrous, phosphoric, phosphorous, perchloric, chloric, chlorous, hypochlorous, carbonic, boric, and their mixtures. 7 - Process according to claim 6 wherein the inorganic acid is hydrogen chloride and the content of inorganic acid in the concentrated portion obtained in step (b) is greater than or equal to 0.3 g / kg and lower or equal to 170 g / kg.

8 - Process according to claim 5 wherein the inorganic salt is selected from halides, sulphates, hydrogen sulphates, sulphites, hydrogen sulphites, sulphides, hydrogen sulphides, nitrates, nitrites, phosphates, hydrogen phosphates, phosphites. , hydrogenophosphites, perchlorates, chlorates, hypochlorites, carbonates, hydrogencarbonates, percarbonates, borates and metal perborates, and mixtures thereof.

9 - Process according to claim 8 wherein the inorganic salt is sodium chloride and the salt content in the concentrated portion obtained in step (b) is greater than or equal to 0.4 g / kg and less than or equal to 280 g / kg.

10 - Process according to any one of claims 1 to 9 wherein the separation is carried out at a temperature greater than or equal to 10 ° C and less than or equal to 100 ° C.

11 - Process according to any one of claims 1 to 10 wherein the water content of the concentrated portion obtained in step (c) is less than or equal to 5% by weight.

12 - Process according to any one of claims 1 to 11 wherein the polyhydroxylated aliphatic hydrocarbon, the polyhydroxylated aliphatic hydrocarbon ester, or the mixture of them, is obtained from renewable raw materials.

13 - Process according to any one of claims 1 to 12 wherein the chlorinating agent contains hydrogen chloride.

14 - Process according to claim 13 wherein the hydrogen chloride is a combination of gaseous hydrogen chloride and an aqueous solution of hydrogen chloride or an aqueous solution of hydrogen chloride.

15 - Process according to any one of claims 1 to 14 wherein the additive is present in the mixture obtained in step (a). 16 - Process according to any one of claims 1 to 15, wherein the polyhydroxylated aliphatic hydrocarbon is selected from ethylene glycol, propylene glycol, chloropropanediol, glycerol and mixtures of at least two of them.

17 - Process according to any one of claims 1 to 16, wherein the chlorohydrin is selected from chloroethanol, chloropropanol, chloropropanediol, dichloropropanol and mixtures of at least two of them.

18 - Process according to claim 16 or 17, wherein the polyhydroxylated aliphatic hydrocarbon is glycerol and the chlorohydrin is dichloropropanol.

19 - Process according to claim 18 sui of a manufacture of epichlorohydrin by dehydrochlorination of dichloropropanol.

20 - Process according to claim 19 wherein the epichlorohydrin is in a manufacture of epoxy resins.