HK1105980B - Method for making an epoxide - Google Patents

Abstract

CN 101006068A

Description

Process for preparing epoxides

This patent application claims priority to patent application FR05.05120 and patent application EP 05104321.4, filed on 5/20/2005, and to us provisional patent applications 60/734659, 60/734627, 60/734657, 60/734658, 60/734635, 60/734634, 60/734637 and 60/734636, filed on 11/8/2005, the contents of which are incorporated herein by reference.

The present invention relates to a process for preparing an epoxide. Epoxides are important starting materials for the production of other compounds.

For example, ethylene oxide is used in the production of ethylene glycol, diethylene glycol and polyethylene glycol, monoethanolamine, diethanolamine and triethanolamine, and the like (see k. weisselmel and h. -j. arm in industrial Organic Chemistry, Third completed revived Edition, vcheiditor, 1997, page 149). Propylene oxide is an important intermediate for the preparation of 1, 2-propanediol, dipropylene glycol, ethers of propylene glycol, isopropylamine, and the like (see k. weisselmel and h. -j. arm in Industrial Organic Chemistry, Third completed revise edition, VCH Editor, 1997, page 275). Epichlorohydrin is an important raw material for the production of glycerol, epoxy resins, synthetic elastomers, glycidyl ethers, polyamide resins, etc. (cf. Ullmann's Encyclopedia of Industrial Chemistry, fast edition, vol. A9, p.539).

The most common technique for the industrial production of propylene oxide comprises the following steps: hypochlorination of propene into monochloropropaneol and dehydrochlorination of monochloropropaneol into propylene oxide by means of an aqueous alkaline solution.

The most common technique for the industrial production of propylene oxide comprises the following steps: high temperature free radical substitution chlorination of propylene or allyl chloride, hypochlorination of allyl chloride to synthesize dichloropropanol, and dehydrochlorination of dichloropropanol to epichlorohydrin by aqueous alkaline solutions. Another technique used at smaller scales includes the following steps: catalyzing the acetoxylation of propylene to allyl acetate, the hydrolysis of allyl acetate to allyl alcohol, the catalytic chlorination of allyl alcohol to dichloropropanol, and the alkaline dehydrochlorination of dichloropropanol to epichlorohydrin. Other techniques that may be considered have not achieved commercial application, including the direct catalytic oxidation of allyl chloride to epichlorohydrin using hydrogen peroxide, or the chlorination of glycerol to dichloropropanol followed by the alkaline dehydrochlorination of dichloropropanol to form epichlorohydrin.

According to the present invention, it has been found that there is a problem that halogenated ketones are formed as by-products, especially when chlorohydrins obtained by chlorinating polyhydroxylated aliphatic hydrocarbons in a dehydrochlorination reaction are used. These haloketones can have boiling temperatures very close to the epoxide, making separation by distillation operations difficult. It has also been found according to the invention that the haloketones are responsible, even at low concentrations, for undesirable coloration of the epoxides or of the products produced from the epoxides. This is particularly significant for the chloropropanone which is formed during the process (or method) of dehydrochlorination of dichloropropanol to epichlorohydrin.

It has also been surprisingly found that these ketones can be removed during the preparation of the epoxide.

Accordingly, the present invention provides a process for the preparation of an epoxide, wherein a halogenated ketone is formed as a by-product and the process comprises at least one treatment to remove at least part of the halogenated ketone formed.

More specifically, the present invention provides a process for the preparation of an epoxide, wherein a haloketone is formed as a by-product and the process comprises at least one treatment to remove at least a portion of the haloketone formed, and wherein the epoxide is prepared by dehydrochlorination of a chlorohydrin.

The chlorohydrin may be obtained by the process of hypochlorination of olefins or by the process of chlorination of multihydroxylated-aliphatic hydrocarbons, esters of multihydroxylated-aliphatic hydrocarbons or mixtures thereof.

The term "epoxide" is used to describe a compound containing at least one oxygen bridged to a carbon-carbon bond. In general, the carbon atoms of the carbon-carbon bond are adjacent, and the compound may contain atoms other than carbon and oxygen atoms, such as hydrogen and halogen. Preferred epoxides are ethylene oxide, propylene oxide, glycidol and epichlorohydrin.

The term "olefin" as used herein is intended to describe a compound containing at least one carbon-carbon double bond. Generally, the compound may contain atoms other than carbon atoms, such as hydrogen atoms and halogens. Preferred olefins are ethylene, propylene, allyl chloride and mixtures of at least two thereof.

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

Polyhydroxylated aliphatic hydrocarbons with hydroxyl (OH) functionality may not have more than one OH group per carbon and must be sp3 hybridized. The carbon atom bearing the OH group may be a primary, secondary or tertiary carbon. The polyhydroxylated aliphatic hydrocarbon used in the present invention must contain at least two sp3 hybridized carbon atoms bearing one 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 order sequences of these repeating units, which may be contiguous or adjacent. The definition of 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. For example gem-diols are excluded from this class of polyhydroxylated aliphatic hydrocarbons.

The polyhydroxylated aliphatic hydrocarbons may contain aromatic moieties or heteroatoms, including heteroatoms of the type such as halogens, sulfur, phosphorus, nitrogen, oxygen, silicon and boron, and mixtures thereof.

The polyhydroxylated aliphatic hydrocarbons which may be used in the present invention include: such as 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, cyclohexanediol, 1, 2-butanediol, 1, 2-cyclohexanedimethanol, 1, 2, 3-propanetriol (also known as "glycerol" or "glycerol"), and mixtures thereof. Preferred polyhydroxylated aliphatic hydrocarbons for use in the present invention include: such as 1, 2-ethanediol, 1, 2-propanediol, 1, 3-propanediol, 1, 2, 3-propanetriol, and mixtures of at least two thereof. More preferably, the polyhydroxylated aliphatic hydrocarbons useful in the present invention include: such as 1, 2-ethanediol, 1, 2-propanediol, chloropropanediol and 1, 2, 3-propanetriol, and also mixtures of at least two of these. Most preferred is 1, 2, 3-propanetriol or glycerol.

The esters of polyhydroxylated aliphatic hydrocarbons may be present in the polyhydroxylated aliphatic hydrocarbons and/or may be formed during the process for the preparation of chlorohydrins according to the invention and/or may be prepared before the process for the preparation of chlorohydrins. Examples of the esters of polyhydroxylated aliphatic hydrocarbons include: ethylene glycol monoacetate, propylene glycol monoacetate, glycerol monostearate, glycerol diacetate, and mixtures thereof.

In the process according to the invention, the esters of polyhydroxylated aliphatic hydrocarbons may originate from the reaction of polyhydroxylated aliphatic hydrocarbons with organic acids, which are subsequently reacted with chlorinating agents before, during or within these steps.

The term "chlorohydrin" is used herein to describe a compound containing at least one hydroxyl group and at least one chlorine atom attached to different saturated carbon atoms. A chlorohydrin containing at least two hydroxyl groups is also a polyhydroxylated aliphatic hydrocarbon. Thus, the starting material and the product of the reaction may each be a chlorohydrin. In this case, the "product" chlorohydrin is more deeply chlorinated than the starting chlorohydrin, in other words, the product chlorohydrin 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 thereof. Dichloropropanol is particularly preferred. Particularly preferred chlorohydrins are 2-chloroethanol, 1-chloroprop-2-ol, 2-chloroprop-1-ol, 1-chloroprop-2, 3-diol, 2-chloroprop-1, 3-diol, 1, 3-dichloropropan-2-ol, 2, 3-dichloropropan-1-ol and mixtures of at least two of these.

In the process according to the invention, the chlorohydrin may be obtained starting from a fossil (fossil) starting material or starting from a renewable starting material, preferably from a renewable starting material.

By fossil feedstock is meant, among other things, feedstock derived from the processing of petrochemical natural resources such as oil, natural gas and coal. Preferred among these materials are organic compounds containing 2 and 3 carbon atoms. Allyl chloride, allyl alcohol and "synthetic" glycerol are particularly preferred when the chlorohydrin is dichloropropanol or chloropropanediol. Wherein "synthetic" glycerol refers to glycerol typically derived from petrochemical resources. Ethylene and "synthetic" ethylene glycol are particularly preferred when the chlorohydrin is chloroethanol. Wherein "synthetic" ethylene glycol refers to ethylene glycol typically derived from petrochemical resources. Propylene and "synthetic" propylene glycol are particularly preferred when the chlorohydrin is monochloropropaneol.

Wherein renewable raw materials refer to raw materials obtained by processing renewable natural resources. Preferred among these materials are "natural" ethylene glycol, "natural" propylene glycol, and "natural" glycerol. "natural" ethylene glycol, propylene glycol and glycerol are obtained by conversion of sugars, which can be obtained starting from biomass, for example by thermochemical processes, as described in "industrial bioproducts: today and Tomorrow ", Energetics, Incorporated for the U.S. department of Energy, Office of Energy Efficiency and Renewable Energy, Office of the biological Program, July 2003, pages 49, 52 to 56. One of these methods is, for example, the catalytic hydrogenolysis of sorbitol obtained from the thermochemical conversion of glucose. Another method is, for example, the catalytic hydrogenolysis of xylitol obtained by the hydrogenation of xylose. Xylose can be obtained, for example, by hydrolysis of the hemicellulose present in corn fiber. By "natural glycerol" or "glycerol obtained starting from renewable raw materials" is meant, in particular, glycerol obtained in the production of biodiesel or in processes such as saponification, transesterification or hydrolysis reactions, which generally convert animal or vegetable oils or fats.

Among the oils that can be used to prepare natural glycerol, mention may be made of all the usual oils, such as palm oil, palm kernel oil, coconut oil, babassu oil, former or new (low erucic acid) rapeseed oil, sunflower (seed) oil, corn oil, castor oil and cotton (seed) oil, peanut oil, soybean oil, linseed oil and crambe oil, and all the oils obtained from sunflower or rapeseed crops, for example obtained by genetic modification or hybridization.

Used frying oils, various animal oils, such as fish oil, beef tallow, lard and even dismembered grease may also be used.

Among the oils used there may also be mentioned oils which are partially modified by, for example, multimerisation or oligomerisation, such as "fixed oils" (or polymeric oils) of linseed oil and sunflower oil, and blown vegetable oils.

A particularly suitable glycerol is obtained during the conversion of animal fat. Another particularly suitable glycerol is obtained in the production of biodiesel. A third particularly suitable glycerol may be obtained in the conversion of animal or vegetable fats and oils by transesterification in the presence of a heterogeneous catalyst, as described in applications FR 2752242, FR 2869612 and FR 2869611. More particularly, the heterogeneous catalyst is selected from the group consisting of 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 aluminum, and the heterogeneous catalyst is used in the form of a fixed bed. This latter process may be a process for producing biodiesel.

The chloroethanol may be obtained starting from these starting materials by any method. Processes for hypochlorating ethylene and chlorinating "synthetic" and/or "natural" ethylene glycol are preferred. The process of chlorinating "synthetic" and/or "natural" ethylene glycols is particularly preferred.

The chloropropanol may be obtained starting from these starting materials by any process. Processes for hypochlorination of propylene and chlorination of "synthetic" and/or "natural" propylene glycol are preferred. The method of chlorinating "synthetic" and/or "natural" propylene glycol is particularly preferred.

The chloropropanediol may be obtained starting from these starting materials by any process. Methods of chlorinating "synthetic" and/or "natural" glycerol are preferred.

Dichloropropanol may be obtained starting from these starting materials by any method. Methods of hypochlorating allyl chloride, chlorinated allyl alcohol, and chlorinating "synthetic" and/or "natural" glycerol are preferred. The method of chlorinating "synthetic" and/or "natural" glycerol is particularly preferred.

In the process for producing an epoxide according to the present invention, it is preferred that at least a part of the chlorohydrin may be produced by chlorinating the polyhydroxylated aliphatic hydrocarbon. The polyhydroxylated aliphatic hydrocarbons may be "synthetic" or "natural" and have the meaning as defined above.

In the preparation process according to the invention, when the epoxide is epichlorohydrin, it is preferably formed from "natural" glycerol, in other words glycerol obtained during the production of biodiesel or during the conversion of animal or vegetable oils or fats, chosen from saponification, transesterification and hydrolysis reactions. Glycerol obtained by transesterification of oils or fats of vegetable or animal origin, which may be carried out in the presence of heterogeneous catalysts, is particularly preferred. In the Process for preparing epoxides according to the invention, the polyhydroxylated aliphatic hydrocarbon may be as described in the patent application entitled "Process for preparing chlorinated polyhydroxylated aliphatic hydrocarbons" filed on even date herewith in the name of SOLVAY SA, the contents of which are incorporated herein by reference.

There is specifically mentioned a process for producing a chlorohydrin in which a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof having a total metal content, expressed in elemental form, of 0.1. mu.g/kg or more and 1000mg/kg or less is reacted with a chlorinating agent.

A first advantage associated with this latter type of glycerol is that it contains little or no metal. These metals may be detrimental to certain steps of the process for preparing dichloropropanol, such as residue handling steps. A second advantage associated with this latter type of glycerol is that it contains little or no heavy organic compounds that can accumulate in the preparation of dichloropropanol. Thus, the cleaning (or discharge) operations used to remove these heavy organic compounds can be reduced.

In the process for preparing epoxides according to the invention, chlorohydrins obtained by reaction with a chlorinating agent starting from polyhydroxylated aliphatic hydrocarbons may be used, for example according to the process described in application WO 2005/054167 to SOLVAY SA, the content of which is incorporated herein by reference.

In the process for preparing epoxides according to the invention, the polyhydroxylated aliphatic hydrocarbon may be a crude or purified product, as described on page 2, line 8 to page 4, line 2 of application WO 2005/054167 of SOLVAY SA.

The crude product may contain fatty acids, fatty acid esters, such as monoglycerides and diglycerides, among others, optionally in combination with water or metal salts. It is preferred to use purified glycerol, i.e. glycerol containing at least 80% and not more than 99.9% by weight of glycerol, at least 0.1% and not more than 20% by weight of water, at least 1mg/kg and not more than 0.1% by weight of aldehydes and at least 10mg/kg and not more than 10% by weight of methanol or ethanol.

In the Process for preparing epoxides according to the invention, the polyhydroxylated aliphatic hydrocarbon may be a polyhydroxylated aliphatic hydrocarbon having a content of alkali metals and/or alkaline earth metals of less than or equal to 5g/kg, as described in the application entitled "Process for preparing a polyhydroxylated aliphatic hydrocarbon" filed on even date herewith in the name of SOLVAY SA, the content of which is incorporated herein by reference.

In the process according to the invention, the content of alkali metal and/or alkaline earth metal in the polyhydroxylated aliphatic hydrocarbon, the ester of polyhydroxylated aliphatic hydrocarbon or the mixture thereof is less than or equal to 5g/kg, often less than or equal to 1g/kg, more particularly less than or equal to 0.01g/kg and in some cases less than or equal to 2 mg/kg. The content of alkali metal and/or alkaline earth metal in the polyhydroxylated aliphatic hydrocarbon is usually 0.1. mu.g/kg or more.

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

In the process for preparing a chlorohydrin according to the invention, the lithium content in the polyhydroxylated aliphatic hydrocarbon, the ester of a polyhydroxylated aliphatic hydrocarbon or the mixture thereof is generally equal to or less than 1g/kg, frequently equal to or less than 0.1g/kg, and more particularly equal to or less than 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

In the process according to the invention, the sodium content of the polyhydroxylated aliphatic hydrocarbon, of the ester of a polyhydroxylated aliphatic hydrocarbon or of the mixture thereof is generally less than or equal to 1g/kg, often less than or equal to 0.1g/kg, and more particularly less than or equal to 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

In the process according to the invention, the potassium content in the polyhydroxylated aliphatic hydrocarbon, the ester of polyhydroxylated aliphatic hydrocarbon or the mixture thereof is generally less than or equal to 1g/kg, often less than or equal to 0.1g/kg, and more particularly less than or equal to 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

In the process according to the invention, the rubidium content of the polyhydroxylated aliphatic hydrocarbon, of the ester of polyhydroxylated aliphatic hydrocarbon or of the mixture thereof is generally equal to or less than 1g/kg, frequently equal to or less than 0.1g/kg, and more particularly equal to or less than 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

In the process according to the invention, the cesium content in the polyhydroxylated aliphatic hydrocarbon, the ester of polyhydroxylated aliphatic hydrocarbon or the mixture thereof is generally less than or equal to 1g/kg, often less than or equal to 0.1g/kg, and more particularly less than or equal to 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

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

In the process according to the invention, the magnesium content of the polyhydroxylated aliphatic hydrocarbon, of the ester of a polyhydroxylated aliphatic hydrocarbon or of the mixture thereof is generally less than or equal to 1g/kg, often less than or equal to 0.1g/kg, and more particularly less than or equal to 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

In the process according to the invention, the calcium content of the polyhydroxylated aliphatic hydrocarbon, of the ester of a polyhydroxylated aliphatic hydrocarbon or of the mixture thereof is generally less than or equal to 1g/kg, often less than or equal to 0.1g/kg, and more particularly less than or equal to 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

In the process according to the invention, the strontium content of the polyhydroxylated aliphatic hydrocarbon, of the ester of a polyhydroxylated aliphatic hydrocarbon or of the mixture thereof is generally less than or equal to 1g/kg, often less than or equal to 0.1g/kg, and more particularly less than or equal to 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

In the process according to the invention, the barium content of the polyhydroxylated aliphatic hydrocarbon, of the ester of a polyhydroxylated aliphatic hydrocarbon or of the mixture thereof is generally less than or equal to 1g/kg, often less than or equal to 0.1g/kg, and more particularly less than or equal to 2 mg/kg. The content is usually 0.1. mu.g/kg or more.

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

In the process for preparing epoxides according to the invention, the chlorinating agent for the polyhydroxylated aliphatic hydrocarbon, the ester of polyhydroxylated aliphatic hydrocarbon or the mixture thereof may be hydrogen chloride and/or hydrochloric acid, as described in the SOLVAY SA application WO 2005/054167, page 4, line 30 to page 6, line 2.

The hydrogen chloride can be generated from the pyrolysis of organic chlorides, for example from the (process) preparation of vinyl chloride, from the preparation of methylene diphenyl-4, 4-diisocyanate (diphenylmethane-4, 4-diisocyanate, MDI) or Toluene Diisocyanate (TDI), from the pickling of metals or from the reaction of inorganic acids such as sulfuric acid or phosphoric acid with metal chlorides such as sodium chloride, potassium chloride or calcium chloride.

In an advantageous embodiment of the process for the preparation of epoxides according to the invention, the chlorinating agent for the polyhydroxylated aliphatic hydrocarbon is gaseous hydrogen chloride or aqueous hydrogen chloride solution, or a combination of both.

In the Process for the preparation of epoxides according to the invention, the chlorinating agent for the polyhydroxylated aliphatic hydrocarbon may be an aqueous hydrochloric acid solution or preferably anhydrous hydrogen chloride, as obtained, for example, from the preparation of allyl chloride and/or methyl chloride and/or from the chlorinolysis and/or high-temperature oxidation of chloride, as filed on even date herewith in the name of SOLVAY SA under the name "Process for preparing a chlorinated and hydrogenated aliphatic hydrocarbon with a chlorine

Mention is made in particular of a process for the preparation of a chlorohydrin starting from a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof, and a chlorinating agent comprising at least one of the following compounds: nitrogen (gas), oxygen (gas), hydrogen (gas), chlorine gas, organic hydrocarbon compounds, organic halogen compounds, organic oxides, and metals.

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

Mention may in particular be made of an unsaturated aliphatic hydrocarbon chosen from acetylene, ethylene, propylene, butylene, propadiene, methylacetylene and mixtures thereof, a saturated aliphatic hydrocarbon chosen from methane, ethane, propane, butane and mixtures thereof, and the aromatic hydrocarbon benzene.

Mention may in particular be made of organohalogen compounds selected from the group consisting of organic chlorides of methyl chloride, ethyl chloride, propyl chloride, butyl chloride, vinyl chloride, vinylidene chloride, monochloropropene, perchloroethylene, trichloroethylene, chloroprene, chlorobenzene and mixtures thereof.

Particular mention is made of an organohalogen compound of organofluoro compounds selected from fluoromethane, fluoroethane, vinyl fluoride, vinylidene fluoride and mixtures thereof.

Mention is made in particular of an organic oxide selected from alcohols, chlorohydrins, chlorinated ethers and mixtures thereof.

Mention may in particular be made of a metal selected from the group consisting of alkali metals, alkaline earth metals, iron, nickel, copper, lead, arsenic, cobalt, titanium, cadmium, antimony, mercury, zinc, selenium, aluminium, bismuth and mixtures thereof.

More particularly a process is mentioned in which the chlorinating agent is at least partially obtained from a process for the preparation of allyl chloride and/or a process for the preparation of methyl chloride and/or a chlorinolysis process and/or a process for the oxidation of chloride at a temperature higher than or equal to 800 ℃.

In an advantageous embodiment of the process for preparing epoxides according to the invention, the chlorinating agent for the polyhydroxylated aliphatic hydrocarbon does not contain gaseous hydrogen chloride.

In the process for preparing epoxides according to the invention, the chlorination of the polyhydroxylated aliphatic hydrocarbon can be carried out in a reactor as described on page 6, line 3 to line 23 in application WO 2005/054167 of SOLVAY SA.

Mention is made in particular of a device made of or coated (or covered) with a material resistant to chlorinating agents, in particular hydrogen chloride, under the reaction conditions. More particularly, a device made of enamelled steel or tantalum is mentioned.

In the Process for preparing an epoxide according to the present invention, the chlorination reaction of the polyhydroxylated aliphatic hydrocarbon, the ester of a polyhydroxylated aliphatic hydrocarbon or the mixture thereof may be carried out in an apparatus made of or coated (or covered) with a material resistant to chlorination agents, as described in the application entitled "Process for preparing a chlorinated hydrocarbon coating-resistant admixture" filed on even date herewith in the name of SOLVAY SA, the contents of which are incorporated herein by reference.

In particular, a process for the preparation of chlorohydrins is mentioned, comprising a step in which a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof is reacted with a chlorinating agent comprising hydrogen chloride, and at least one further step carried out in a plant made of or coated with a material resistant to the chlorinating agent under the conditions in which said step is carried out. More particular mention may be made of metallic materials such as enamelled steel, gold and tantalum, and non-metallic materials such as high density polyethylene, polypropylene, poly (vinylidene fluoride), polytetrafluoroethylene, perfluoroalkoxyalkanes and poly (perfluoropropyl vinyl ether), polysulphones and polysulphides, and also graphite including impregnated graphite.

In the process for preparing epoxides according to the invention, the chlorination of the polyhydroxylated aliphatic hydrocarbon, the ester of a polyhydroxylated aliphatic hydrocarbon or the mixture thereof may be carried out in a reaction mixture as described in the application entitled "Continuous Process for preparingchlorohydrins" filed on the same day as the present application in the name of SOLVAY SA, the content of which is incorporated herein by reference.

Mention is made in particular of a continuous process for the preparation of chlorohydrins in which a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon, or a mixture thereof, is reacted with a chlorinating agent and an organic acid in a liquid reaction mixture, the steady-state composition (or steady-state composition) of which contains a multihydroxylated-aliphatic hydrocarbon and an ester of a multihydroxylated-aliphatic hydrocarbon, the total amount of the multihydroxylated-aliphatic hydrocarbon and the ester of a multihydroxylated-aliphatic hydrocarbon, expressed in moles of multihydroxylated-aliphatic hydrocarbon, being greater than 1.1 mol% and less than or equal to 30 mol%, the percentages being based on the organic fraction of the liquid reaction mixture.

The organic part of the liquid reaction mixture is composed of all the organic compounds in the liquid reaction mixture, in other words, compounds whose molecules contain at least 1 carbon atom.

In the process for preparing epoxides according to the invention, the chlorination of the polyhydroxylated aliphatic hydrocarbon can be carried out in the presence of a catalyst as described, for example, in the application WO 2005/054167 of SOLVAY SA, page 6, line 28 to page 8, line 5.

Mention may in particular be made of a catalyst based on a carboxylic acid or a carboxylic acid derivative, in particular adipic acid and derivatives of adipic acid, having a boiling point greater than or equal to 200 ℃ at atmospheric pressure.

In the process for preparing epoxides according to the invention, the chlorination of the polyhydroxylated aliphatic hydrocarbon can be carried out at catalyst concentrations, temperatures and pressures and residence times as described, for example, in the application WO 2005/054167 of SOLVAY SA, page 8, line 6 to page 10, line 10.

Particular mention is made of a temperature of at least 20 ℃ and not more than 160 ℃, a pressure of at least 0.3 bar and not more than 100 bar and a residence time of at least 1h and not more than 50 h.

In the process for preparing epoxides according to the invention, the chlorination of the polyhydroxylated aliphatic hydrocarbon may be carried out in the presence of a solvent as described, for example, in the application WO 2005/054167 of SOLVAY SA, page 11, lines 12 to 36.

Mention may in particular be made of anhydrous solvents such as chlorinated organic solvents, alcohols, ketones, esters or ethers, such as chloroethanol, chloropropanol, chloropropanediol, dichloropropanol, dioxane, phenol, cresol and mixtures of chloropropanediol and dichloropropanol, which are miscible with the polyhydroxylated aliphatic hydrocarbon, or such organic solvents as reaction heavy products such as oligomers in which the polyhydroxylated aliphatic hydrocarbon is at least partially chlorinated and/or esterified.

In the preparation of epoxides according to the invention, the chlorination of the polyhydroxylated aliphatic hydrocarbon may be carried out in the presence of a liquid phase containing a heavy compound different from the polyhydroxylated aliphatic hydrocarbon, as described in the application entitled "Process for preparing a chlorohydrin a liquid phase" filed on the same day as the present application in the name of SOLVAY SA, the content of which is incorporated herein by reference.

There is particularly mentioned a process for the preparation of a chlorohydrin in which a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon, or a mixture thereof is reacted with a chlorinating agent in the presence of a liquid phase containing a heavy compound different from the multihydroxylated-aliphatic hydrocarbon, and the heavy compound has a boiling temperature at 1 bar absolute that is at least 15 ℃ higher than the boiling temperature of the chlorohydrin at 1 bar absolute.

In the process for preparing an epoxide according to the present invention, the reaction of the chlorinated polyhydroxylated aliphatic hydrocarbon, the ester of a polyhydroxylated aliphatic hydrocarbon or the mixture thereof may be carried out in a batch manner or a continuous manner. Particularly preferred is a continuous mode.

In the process for preparing epoxides according to the invention, the chlorination of the polyhydroxylated aliphatic hydrocarbon is preferably carried out in a liquid reaction mixture. The liquid reaction mixture may be single-phase or multi-phase.

The liquid reaction mixture consists of all of dissolved or dispersed solid compounds, dissolved or dispersed liquid compounds and dissolved or dispersed gaseous compounds at the reaction temperature.

The reaction mixture contains reactants, catalyst, solvent, impurities present in the reactants, in the solvent and in the catalyst, reaction intermediates, reaction products and reaction by-products.

Wherein the reactants are the polyhydroxylated aliphatic hydrocarbon, the ester of polyhydroxylated aliphatic hydrocarbon and the chlorinating agent.

The impurities present in the polyhydroxylated aliphatic hydrocarbon may include carboxylic acids, carboxylic acid salts, esters of fatty acids with the polyhydroxylated aliphatic hydrocarbon, esters of fatty acids with alcohols used for transesterification, and inorganic salts such as sulfates or chlorides of alkali metals or alkaline earth metals.

When the polyhydroxylated aliphatic hydrocarbon is glycerol, the impurities in glycerol may include carboxylic acids, carboxylic acid salts, fatty acid esters such as monoglycerides, diglycerides and triglycerides, esters of fatty acids with alcohols used for transesterification, and inorganic salts such as sulfates and chlorides of alkali metals or alkaline earth metals.

The reaction intermediates may include monochlorohydrins of the polyhydroxylated aliphatic hydrocarbons and their esters and/or polyesters, esters and/or polyesters of the polyhydroxylated aliphatic hydrocarbons and esters of the polychlorohydrin (or polychlorinated alcohols).

When the chlorohydrin is dichloropropanol, the reaction intermediates may include monochlorohydrin of glycerol and its esters and/or polyesters, esters and/or polyesters of glycerol and esters of dichloropropanol.

Thus, the ester of the polyhydroxylated aliphatic hydrocarbon may be a reactant, an impurity of the polyhydroxylated aliphatic hydrocarbon or a reaction intermediate, as appropriate.

Wherein the reaction product is the chlorohydrin and water. The water may be water formed in the chlorination reaction and/or water introduced into the process (or process) by e.g. the polyhydroxylated aliphatic hydrocarbon and/or the chlorinating agent, as described in the SOLVAY SA application WO 2005/054167, page 2, line 22 to line 28 and page 3, line 20 to line 25, page 5, line 7 to line 31 and page 12, line 14 to line 19.

The by-products may include, for example, partially chlorinated and/or esterified oligomers of the polyhydroxylated aliphatic hydrocarbon.

When the polyhydroxylated aliphatic hydrocarbon is glycerol, the by-products may include, for example, oligomers in which glycerol is partially chlorinated and/or esterified.

The reaction intermediates and by-products may be formed in different steps of the process, for example in the step of preparing the chlorohydrin and in the step of isolating the chlorohydrin.

Thus, the liquid reaction mixture may contain the polyhydroxylated aliphatic hydrocarbon, chlorinating agent dissolved or dispersed in the form of bubbles, catalyst, solvent, impurities such as dissolved or solid salts present in the reactants, solvent and catalyst, such as reaction intermediates, reaction products and by-products.

In the process according to the invention, the chlorohydrin may be separated from the reaction mixture from the other compounds according to the process as described in the application WO 2005/054167 of SOLVAY SA, page 12, line 1 to page 16, line 35 and page 18, line 6 to line 13. The separation specifically mentioned is carried out by azeotropic distillation of the mixture of water/chlorohydrin/chlorinating agent with minimum loss of chlorinating agent, followed by separation of the chlorohydrin by decantation (or decantation or phase separation). These other compounds are mentioned above and include unconsumed reactants, impurities present in the reactants, catalysts, solvents, reaction intermediates, water and reaction by-products.

In the process according to the invention, the separation of the chlorohydrin and other compounds from the reaction mixture may be carried out according to the process described in patent application EP 05104321.4 filed in the name of SOLVAY SA 5/20/2005, the content of which is incorporated herein by reference.

There is particularly mentioned a process for the preparation of a chlorohydrin by reacting a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon, or a mixture thereof, with a chlorinating agent, wherein the multihydroxylated-aliphatic hydrocarbon, the ester of a multihydroxylated-aliphatic hydrocarbon, or the mixture thereof used contains at least one solid or dissolved metal salt, the process comprising a separation operation for removing part of the metal salt. More particularly mentioned is a process for the preparation of a chlorohydrin by reacting a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon, or a mixture thereof with a chlorinating agent, wherein the multihydroxylated-aliphatic hydrocarbon, the ester of a multihydroxylated-aliphatic hydrocarbon, or the mixture thereof used contains at least one chloride and/or sulfate of sodium and/or potassium, and wherein the separation operation for removing part of the metal salts in the process is a filtration operation. Also specifically mentioned is a process for producing a chlorohydrin, wherein (a) a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon, or a mixture thereof is reacted with a chlorinating agent in a reaction mixture, (b) a part (or fraction) of a reaction mixture containing at least water and the chlorohydrin is continuously or periodically removed, (c) at least a part of the (or 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 the distillation step. In particular, a process for the preparation of chlorohydrins is mentioned, in which (a) polyhydroxylated aliphatic hydrocarbons, esters of polyhydroxylated aliphatic hydrocarbons or mixtures thereof are reacted with hydrogen chloride in a reaction mixture, (b) a portion (or fraction) of the reaction mixture containing at least water and chlorohydrin is continuously or periodically removed, (c) at least a portion of the portion (or fraction) obtained in step (b) is introduced into a distillation step, wherein the ratio of the hydrogen chloride content to the water content in the portion (or fraction) introduced into the distillation step is less than the ratio of the hydrogen chloride/water content in the binary azeotropic composition of hydrogen chloride/water at the distillation temperature and pressure.

In the Process for preparing epoxides according to the invention, the separation of the chlorohydrin and other compounds from the reaction mixture derived from the chlorinated polyhydroxyaliphatic hydrocarbon, the ester of a polyhydroxyaliphatic hydrocarbon or the mixture thereof may be effected by the Process described in the application entitled "Process for preparing a chlorohydrin", filed on even date herewith in the name of SOLVAY SA, the contents of which are incorporated herein by reference.

Mention is made in particular of a process for the preparation of chlorohydrins comprising the following steps: (a) reacting a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon, or a mixture thereof, with a chlorinating agent and an organic acid, thereby producing a mixture containing a chlorohydrin and an ester of a chlorohydrin, (b) subjecting at least a portion of the mixture obtained in step (a) to one or more treatments in a step subsequent to step (a), and (c) adding the multihydroxylated-aliphatic hydrocarbon in at least one step subsequent to step (a) to react with the ester of a chlorohydrin at a temperature greater than or equal to 20 ℃, thereby at least partially forming the ester of the multihydroxylated-aliphatic hydrocarbon.

More particularly, a process is mentioned in which the polyhydroxylated aliphatic hydrocarbon is glycerol and the chlorohydrin is dichloropropanol.

In the Process for preparing epoxides according to the invention, the separation of chlorohydrins and other compounds from the reaction mixture derived from chlorinated polyhydroxylated aliphatic hydrocarbons, esters of polyhydroxylated aliphatic hydrocarbons or mixtures thereof may be effected as described in the application entitled "Process for preparing a chlorinated polyhydroxylated aliphatic hydrocarbon from an epoxidized aliphatic hydrocarbon" filed on even date herewith in the name of SOLVAY SA, the contents of which are incorporated herein by reference.

Mention is made in particular of a process for the preparation of chlorohydrins by reacting polyhydroxylated aliphatic hydrocarbons, esters of polyhydroxylated aliphatic hydrocarbons or mixtures thereof with a chlorinating agent in a reactor provided with one or more liquid streams containing less than 50% by weight of said polyhydroxylated aliphatic hydrocarbons, esters of polyhydroxylated aliphatic hydrocarbons or mixtures thereof, relative to the weight of the total liquid stream introduced into the reactor. More particularly, a process is mentioned, which comprises the following steps: (a) reacting a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon, or a mixture thereof, with a chlorinating agent to produce at least one mixture comprising the chlorohydrin, water and the chlorinating agent, (b) removing at least a portion (or fraction) of the mixture produced in step (a), and (c) subjecting the portion (or fraction) removed in step (b) to a distillation and/or stripping operation in which the multihydroxylated-aliphatic hydrocarbon is added to separate a mixture comprising water and chlorohydrin in the portion (or fraction) removed in step (b), which has a reduced chlorinating agent content as compared to the portion (or fraction) removed in step (b).

In the Process for the preparation of epoxides according to the invention, the separation of the chlorohydrin and other compounds from the reaction mixture resulting from the chlorination of the polyhydroxylated aliphatic hydrocarbon can be carried out in the same manner as described in the application entitled "Process for converting polyhydroxylated aliphatic hydrocarbons into chlorocarbons" filed on the same day in the name of SOLVAY SA, the content of which is incorporated herein by reference.

Mention is made in particular of a process for the preparation of chlorohydrins comprising the following steps: (a) reacting a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon or a mixture thereof with a chlorinating agent to obtain a mixture containing the chlorohydrin, an ester of a chlorohydrin and water, (b) subjecting at least a part (or fraction) of the mixture obtained in step (a) to a distillation and/or stripping treatment to obtain a batch of product enriched in water, chlorohydrin and an ester of a chlorohydrin, and (c) subjecting at least a part (or fraction) of the batch of product obtained in step (b) to a separation operation in the presence of at least one additive to obtain a fraction enriched in esters of chlorohydrin and containing less than 40% by weight of water.

The separation operation is more particularly a decantation (or decantation).

In the Process according to the invention, the separation and treatment of the other compounds of the reaction mixture can be carried out by the Process as described in the application entitled "Process for preparing a chlorinated hydrogenated alkylated aliphatic hydrocarbon" filed on even date with this application in the name of SOLVAY SA. The preferred treatment method involves subjecting a portion of the reaction by-products to high temperature oxidation.

Mention is made in particular of a process for the preparation of chlorohydrins comprising the following steps: (a) reacting a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof having an alkali metal and/or alkaline earth metal content of 5g/kg or less, a chlorinating agent and an organic acid, thereby obtaining a mixture containing at least a chlorohydrin and by-products, (b) subjecting at least a part of the mixture obtained in step (a) to one or more treatments in a step subsequent to step (a), and (c) subjecting to oxidation at a temperature of 800 ℃ or higher in at least one step subsequent to step (a).

More particularly a process is mentioned in which a portion of the mixture obtained in step (a) is removed in a subsequent step and this portion is oxidized at a temperature greater than or equal to 800 ℃ during the removal. Also particular mention is made of a process in which the treatment of step (b) is a separation operation selected from the group consisting of phase separation, filtration, centrifugation, extraction, washing, evaporation, stripping, distillation and adsorption operations or a combination of at least two of these operations.

In the process according to the invention, when the chlorohydrin is chloropropanol, the chloropropanol is generally used in the form of a mixture comprising 1-chloroprop-2-ol and 2-chloroprop-1-ol as isomeric compounds. The mixture generally contains more than 1% by weight of both isomers, preferably more than 5% by weight, in particular more than 50% by weight. The mixture generally contains less than 99.9% by weight of the two isomers, preferably less than 95% by weight, more particularly less than 90% by weight. Other components of the mixture may be compounds originating from the process for preparing chloropropanol, such as residual reactants, reaction by-products, solvents, in particular water.

The mass ratio between the isomers 1-chloroprop-2-ol and 2-chloroprop-1-ol is generally greater than or equal to 0.01, preferably greater than or equal to 0.4. This ratio is generally equal to or less than 99 and preferably equal to or less than 25.

In the process according to the invention, when the chlorohydrin is a chlorohydrin, the chlorohydrin is generally used in the form of a mixture containing the 2-chlorohydrin isomer compound. The mixture generally contains more than 1% by weight of the isomer, preferably more than 5% by weight, in particular more than 50%. The mixture generally contains less than 99.9% by weight of the isomer, preferably less than 95% by weight, more particularly less than 90% by weight. Other components of the mixture may be compounds originating from the preparation of the chlorohydrin, such as residual reactants, reaction by-products, solvents, in particular water.

In the process according to the invention, when the chlorohydrin is dichloropropanol, said dichloropropanol is generally used in the form of a mixture of isomeric compounds comprising 1, 3-dichloropropan-2-ol and 2, 3-dichloropropan-1-ol. The mixture generally contains more than 1% by weight of the two isomers, preferably more than 5% by weight, in particular more than 50%. The mixture generally contains less than 99.9% by weight of the two isomers, preferably less than 95% by weight, more particularly less than 90% by weight. Other constituents of the mixture may be compounds originating from the preparation of the dichloropropanol, such as residual reactants, reaction by-products, solvents, in particular water.

The mass ratio of 1, 3-dichloropropan-2-ol to 2, 3-dichloropropan-1-ol is generally equal to or greater than 0.01, preferably equal to or greater than 0.4. This ratio is usually 99 or less, preferably 25 or less.

In the process according to the invention, when the chlorohydrin is dichloropropanol and is obtained in a process starting from allyl chloride, the isomeric mixture exhibits a 1, 3-dichloropropan-2-ol: the mass ratio of 2, 3-dichloropropan-1-ol is generally between 0.3 and 0.6, typically close to 0.5. When the dichloropropanol is obtained in a process starting from synthetic and/or natural glycerol, the 1, 3-dichloropropan-2-ol: the mass ratio of 2, 3-dichloropropan-1-ol is generally not less than 1.5, preferably not less than 3.0, in particular not less than 7.0, and especially not less than 20.0. When the dichloropropanol is obtained starting from allyl alcohol, the 1, 3-dichloropropan-2-ol: the mass ratio of 2, 3-dichloropropan-1-ol is often in the order of 0.1.

By haloketone is meant a ketone containing from 3 to 8 carbon atoms, preferably from 3 to 12 carbon atoms, particularly preferably from 3 to 6 carbon atoms, in which one or more hydrogen atoms have been replaced by halogen atoms. They are often chloroketones, more particularly chloroacetone.

These halo ketones can be generated during and/or prior to dehydrochlorination of dichloropropanol in a process for making chlorohydrins under certain conditions. Without being bound by any one theory, in the first case, when the chlorohydrin is dichloropropanol, it is believed that the chloroacetone is essentially produced starting from the isomer 1, 3-dichloropropan-2-ol. In the second case, it has surprisingly been found that the halogenated ketones can be present in large amounts in the chlorohydrins obtained by dehydrochlorination of polyhydroxylated aliphatic hydrocarbons. In this case, the content of halogenated ketone in the chlorohydrin obtained is generally greater than or equal to 0.005% by weight, often greater than or equal to 0.01% by weight, relative to the mixture of isomers of the chlorohydrin. Said content is generally less than or equal to 0.4% by weight, and often less than or equal to 0.3% by weight, with respect to the mixture of isomers of chlorohydrin.

According to a first variant of the process of the invention, the treatment for removing at least part of the halogenated ketone is carried out during the dehydrochlorination of the chlorohydrin.

Regardless of the mechanism of such removal and the final form in which the hydrochloric acid is removed, dehydrochlorination refers to the removal of hydrochloric acid.

Dehydrochlorination may be carried out in any known manner, for example by heating the chlorohydrin in the absence of any (other) reactant other than chlorohydrin, by treating the chlorohydrin with a basic compound in the presence or absence of a catalyst. Preference is given to dehydrochlorination of chlorohydrins by treatment with basic compounds.

Wherein the basic compound is a basic organic compound or a basic inorganic compound. Basic inorganic compounds are preferred. These basic inorganic compounds may be oxides, hydroxides and metal salts such as carbonates, bicarbonates, phosphates or mixtures thereof. Preferred among these metals are alkali metals and alkaline earth metals. Particularly preferred are sodium, potassium and calcium and mixtures thereof. The basic inorganic compound may be present in the form of a solid, liquid or aqueous solution or an organic solution or suspension. Preferably an aqueous solution or suspension. Particularly preferred are NaOH, Ca (OH)₂Purified alkaline salt solutions (or brines) and mixtures thereof. Wherein purified alkaline salt solution (or brine) refers to such caustic soda (or sodium hydroxide) containing NaCl as produced during membrane electrolysis. The amount of the basic compound in the solution or suspension is usually 1% by weight or more, preferably 4% by weight or more. The amount is generally 60% by weight or less. An amount of about 50% by weight is particularly suitable.

The basic compound may be used in a superstoichiometric, substoichiometric or stoichiometric amount relative to the chlorohydrin. When the basic compound is used in substoichiometric amounts, it is generally used in an amount of not more than 2 mol of chlorohydrin per mole of base. Generally, it is used in an amount not exceeding 1.5 moles of chlorohydrin per mole of base, and preferably not exceeding 1.05 moles of chlorohydrin per mole of base. When the alkaline agent is used in a superstoichiometric amount, it is used in an amount not exceeding 2 moles of base per mole of chlorohydrin. In this case, at least 1.05mol of base per mol of chlorohydrin are generally used.

The water content of the mixture containing the chlorohydrin and the basic compound is generally greater than or equal to 8% by weight.

When dehydrochlorination (reaction) is carried out by treating the chlorohydrin with a basic compound, the reaction mixture may also contain solvents such as those described in patent US3,061,615 in the name of SOLVAY SA.

Dehydrochlorination can be accomplished as described in the application entitled "Process for preparing an epoxide starting from polymerized hydrogenated aliphatic hydrocarbon and a chlorinating agent" filed on the same date as the present application in the name of SOLVAY SA, the contents of which are incorporated herein by reference.

Mention is made in particular of a process for preparing epoxides in which a reaction mixture obtained by reacting a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof with a chlorinating agent, which reaction mixture contains at least 10g of chlorohydrin per kg of reaction mixture, is subsequently subjected to a chemical reaction without intermediate work-up.

Mention is also made of the preparation (process) of epoxides, which comprises the following steps: (a) reacting polyhydroxy aliphatic hydrocarbon, polyhydroxy aliphatic hydrocarbon ester or their mixture with chlorinating agent and organic acid, thereby forming an ester of chlorohydrin and chlorohydrin in a reaction mixture containing the polyhydroxylated aliphatic hydrocarbon, an ester of polyhydroxylated aliphatic hydrocarbon, water, a chlorinating agent and an organic acid, the reaction medium containing at least 10g of chlorohydrin per kg of reaction mixture, (b) subjecting at least a portion (or fraction) of the reaction mixture obtained in step (a), said fraction having the same composition as the reaction mixture obtained in step (a), one or more treatments in a step subsequent to step (a), and (c) adding a basic compound in at least one step subsequent to step (a), to at least partially react with the chlorohydrin, chlorohydrin ester, chlorinating agent, and organic acid to form an epoxide and a salt.

The liquid reaction mixture may be single-phase or two-phase.

The alkaline dehydrochlorination treatment may be carried out in a continuous or discontinuous manner.

The duration of the alkaline treatment or, if appropriate, the residence time (or residence time) of the reactants during the alkaline treatment is generally greater than or equal to 0.1s, preferably greater than or equal to 0.3s, particularly preferably greater than or equal to 0.4 s. The duration or residence time is generally less than or equal to 2h, more particularly less than or equal to 1 h. The residence time of the reactants is defined as the ratio between the volume of the reactor occupied by the liquid phase and the cumulative flow rate of the reactants.

The dehydrochlorination treatment according to the present invention is typically carried out at a temperature of at least 0 ℃. Often the temperature is at least 20 ℃. Preferably it is at least 30 ℃. In the process for preparing epoxides according to the invention, the reaction is generally carried out at a temperature not exceeding 140 ℃. Preferably it does not exceed 120 ℃. In a first preferred variant, the temperature is from 25 ℃ to 50 ℃. In a second preferred variant, the temperature is from 50 ℃ to 90 ℃.

In the process for the preparation of epoxides according to the invention, the dehydrochlorination treatment is generally carried out at a pressure of at least 0.08 bar absolute. Often the pressure is at least 0.1 bar absolute. Preferably it is at least 0.2 bar absolute. In the process for the preparation of epoxides according to the invention, the dehydrochlorination treatment is generally carried out at a pressure not exceeding 25 bar absolute. Preferably it is not more than 6 bar absolute. In a first preferred variant, the pressure is from 0.4 to 0.8 bar absolute. In a second preferred variant, the pressure is from 1 to 3 bar.

Epoxides formed in processes for dehydrochlorination of chlorohydrins can be removed by distillation or stripping at the rate at which they are formed. Stripping can be carried out with any gas that is inert to the epoxide. The stripping is preferably carried out with steam.

After the alkaline treatment, the haloketone content of the epoxide is generally equal to or less than 0.01% by weight, preferably equal to or less than 0.005% by weight, particularly preferably equal to or less than 0.003% by weight. Often the epoxide contains at least 0.0001 weight percent of a halogenated ketone.

The invention therefore likewise provides an epoxide having a content of haloketones of 0.01% by weight or less. When the epoxide is epichlorohydrin, its purity is preferably 999g/kg or greater.

Without being bound by any theory, the use of the reactivity of the chlorohydrins, haloketones, and epoxides allows removal of the haloketones by judicious selection of the chlorohydrin dehydrochlorination conditions without adversely affecting the epoxide yield.

According to a second variant of the process of the invention, the treatment for removing at least part of the halogenated ketone, carried out before the dehydrochlorination and capable of removing the fraction substantially consisting of water and halogenated ketone and recovering the chlorohydrin having a reduced content of halogenated ketone, comprises distillation, evaporation and/or stripping in the presence of water.

After the treatment, the chlorohydrin generally has a content of haloketone of 0.1% by weight or less, preferably 0.04% by weight or less, particularly preferably 0.005% by weight or less, relative to the mixture of chlorohydrin isomers. Frequently, the epoxide contains at least 0.0001% by weight of halogenated ketone, relative to the mixture of chlorohydrin isomers.

This treatment is preferably an azeotropic distillation in the presence of water. The reason for this is that it has been found that when the haloketone is chloroacetone, for example water and chloroacetone, form a low boiling point (point bas) binary azeotrope whose composition can be characterized by its boiling temperature, 92 ℃ at 1013 mbar. At this temperature and pressure, the composition consists of 28% by weight of water, 72% by weight of chloroacetone. The two liquid phases were separated after condensation to 25 ℃; the heavier organic phase contained 95 wt.% chloroacetone and 5 wt.% water, while the aqueous phase contained 5 wt.% chloroacetone and 95 wt.% water. It has been found that the exploitation of the liquid/gas equilibrium properties of the binary composition water/chloroacetone makes it possible to remove chloroacetone from dichloropropanol. The water required for the azeotropic distillation may originate, for example, from the process for the synthesis of dichloropropanol, in particular by chlorination of glycerol, or may be subsequently fed to the process.

Accordingly, the present invention also provides an azeotropic composition comprising water and chloroacetone.

FIG. 1 shows a first specific apparatus profile that can be used to practice the preparation of epoxides according to the invention.

The chlorohydrin was supplied to the distillation column via line (1). Water is added to the chlorohydrin via line (2). A vapor comprising water and most of the halogenated ketone is continuously withdrawn from column (3) through line (4). The residue of the column containing purified chlorohydrin is removed via line (5). The basic compound is added to the residue of column (3) via line (6) and the resulting mixture is fed to reactor (8), optionally as a distillation column, via line (7). Steam is introduced into the bottom of the reactor (8) through line (9). Gaseous steam is continuously withdrawn from reactor (8) via line (10) and fed to condenser (12). Liquid vapour is continuously withdrawn from the reactor (8) through line (11). The condensed steam (13) is fed to a phase separator (14). The separated liquid phase is returned to the top of the reactor (8) via a line (15) to ensure reflux. The crude epoxide constitutes the separated organic phase which is removed via line (16). The crude product of this epoxide is purified in a distillation section.

According to a first particular aspect of the process of the invention, use is made of a chlorohydrin containing at least a portion of the chlorohydrin obtained starting from a polyhydroxylated aliphatic hydrocarbon by reaction with a chlorinating agent. In this respect, the chlorohydrins prepared in this part by reaction with a chlorinating agent starting from polyhydroxylated aliphatic hydrocarbons generally constitute at least 1% by weight, preferably at least 5% by weight, more preferably at least 35% by weight, of the total weight of the chlorohydrins. In this particular aspect, the fraction is generally not more than 99% by weight, preferably not more than 60% by weight. The additional chlorohydrin, which may be obtained by any of the other processes (other than the process for preparing chlorohydrins described above), is generally at least 1% by weight, preferably at least 5% by weight, more preferably at least 35% by weight. This fraction is generally not more than 99% by weight, preferably not more than 60% by weight. Among these other processes for the preparation of chlorohydrins, the hypochlorination of olefins is preferred.

Accordingly, the present invention further provides a first process for preparing an epoxide comprising:

(a) a step of preparing a chlorohydrin by hypochlorating an olefin,

(b) a step for preparing chlorohydrins by chlorinating polyhydroxylated aliphatic hydrocarbons, which step is carried out in parallel with step (a), and

(c) the dehydrochlorination step, in which the chlorohydrins obtained in steps (a) and (b) are used, is conventional.

Such a first process for preparing an epoxide preferably comprises a step for removing at least part of the halogenated ketone formed in the process.

According to a first embodiment of the first process for preparing an epoxide according to the invention, the chlorohydrin obtained in steps (a) and (b) is used in step (c).

FIG. 2 shows a second specific apparatus profile that can be used to implement the process for producing an epoxide according to this example.

The distillation column (20) is fed, via line (18), with chlorohydrin coming from the reactor (17) for chlorinating polyhydroxylated aliphatic hydrocarbons. Water is added to the chlorohydrin via line (19). A vapor comprising water and haloketone is continuously withdrawn from column (20) via line (21). The residue of the column is taken off via line (22) and mixed with a liquid stream (24) of chlorohydrin obtained from a reactor (23) for hypochlorination of olefins. To the mixed liquid stream of chlorohydrin is added a basic compound via line (25) and the resulting mixture is fed via line (26) to reactor (27), which may optionally be a distillation column. Steam is introduced into the bottom of the reactor (27) via line (28). Gaseous steam is continuously withdrawn from reactor (27) via line (29) and fed to condenser (31). Liquid vapour is continuously withdrawn from reactor (27) via line (30). The condensed vapor (32) is fed to a phase separator (33). The separated liquid phase is returned to the top of the reactor (27) via a line (34) to ensure reflux. The crude epoxide constitutes the organic phase which is separated off and is taken off via line (35). The crude epoxide is purified in a distillation section.

According to a second embodiment of the first process for the preparation of epoxides of the invention, the chlorohydrins obtained in step (a) or in step (b) are used alternatively or simultaneously in step (c).

The present invention also provides an apparatus for producing an epoxide, comprising:

(a) a reactor for hypochlorating olefins, from which reactor a reaction mixture containing chlorohydrin is withdrawn,

(b) a reactor for chlorinating polyhydroxylated aliphatic hydrocarbons, from which reactor a reaction mixture containing the chlorohydrin is discharged, and

(c) a reactor for dehydrochlorination fed with the reaction mixture produced from reactor (a) and from reactor (b).

The apparatus for producing an epoxide preferably comprises a reactor for removing at least part of the halogenated ketone formed in the apparatus.

The conditions of step (b) may be those described in application WO 2005/054167 and in application EP 05104321.4 filed on 5.20.2005 in the name of SOLVAY SA. The conditions of step (c) are, for example, those described previously in this application.

FIG. 3 shows a third specific apparatus profile that can be used to practice the process for producing an epoxide according to the present invention.

A liquid stream (37) of chlorohydrins coming from a reactor (36) for chlorinating polyhydroxylated aliphatic hydrocarbons is mixed with a liquid stream (39) of chlorohydrins coming from a reactor (38) for hypochlorination of olefins. The basic compound is added to the mixed liquid stream of chlorohydrin via line (40) and the resulting mixture is fed to reactor (42), which may optionally be a distillation column, via line (41). Steam is introduced into the bottom of the reactor (42) via line (43). Gaseous steam is continuously withdrawn from reactor (42) via line (44) and fed to condenser (46). Liquid vapour is continuously withdrawn from reactor (42) via line (45). The condensed liquid stream (47) is fed to a phase separator (48). The separated liquid phase is returned to the top of the reactor (42) via line (49) to ensure reflux. The crude epoxide constitutes the separated organic phase, which is removed via line (50). The crude epoxide is purified in a distillation section.

According to a second particular aspect of the process of the invention, at least part of the epoxide is isolated from the epoxide prepared starting from the chlorohydrin obtained by reacting a polyhydroxylated aliphatic hydrocarbon with a chlorinating agent. In this respect, the chlorohydrins prepared in this part by reaction with a chlorinating agent starting from polyhydroxylated aliphatic hydrocarbons generally constitute at least 1% by weight, preferably at least 5% by weight, more preferably at least 35% by weight, of the total weight of the epoxides. In this particular aspect, the fraction is generally not more than 99% by weight, preferably not more than 60% by weight. The additional epoxide may be obtained by any other process than the process for preparing the chlorohydrin described above, generally at least 1% by weight, preferably at least 5% by weight, more preferably at least 35% by weight. This fraction is generally not more than 99% by weight, preferably not more than 60% by weight.

Among these other processes for the preparation of chlorohydrins, the hypochlorination of olefins is preferred.

Accordingly, the present invention additionally provides a second process for preparing an epoxide comprising

(a) A step of preparing a chlorohydrin by hypochlorating an olefin,

(b) a step of dehydrochlorinating the chlorohydrin obtained in step (a) to produce an epoxide in a dehydrochlorination reaction mixture,

(c) a step for producing a chlorohydrin by chlorinating a polyhydroxylated aliphatic hydrocarbon,

(d) a step of dehydrochlorinating the chlorohydrin obtained in step (c) to produce an epoxide in a dehydrochlorination reaction mixture, and

(e) a step of separating an epoxide from the dehydrochlorination reaction mixture, in which the dehydrochlorination reaction mixture containing the epoxide obtained in the steps (b) and (d) is used,

and wherein step (b) is subsequent to step (a) and step (d) is subsequent to step (c), and the pair of steps consisting of steps (a) and (b) is in parallel with the pair of steps consisting of steps (c) and (d).

Preferably, this second process for preparing epoxides comprises a step for removing at least part of the halogenated ketone formed in the process.

According to a first embodiment of the second process for preparing an epoxide according to the present invention, the epoxide obtained in steps (b) and (d) is used in step (e).

According to a second embodiment of the second 0 process for preparing epoxides of the present invention, the epoxide obtained in step (b) or in step (d) is used alternatively or simultaneously in step (e).

The present application also provides an apparatus for producing an epoxide, comprising:

(a) a reactor for hypochlorating olefins, from which reactor a reaction mixture containing chlorohydrin is withdrawn,

(b) a reactor for dehydrochlorination to which the reaction mixture generated from the reactor (a) is supplied and from which a reaction mixture containing the epoxide is discharged,

(c) a reactor for chlorinating polyhydroxylated aliphatic hydrocarbons, from which reactor a reaction mixture containing the chlorohydrin is discharged,

(d) a reactor for dehydrochlorination to which the reaction mixture produced in step (b) is supplied and from which a reaction mixture containing the epoxide is discharged, and

(e) a separator supplied with the reaction mixture discharged from step (b) and discharged from step (d),

and wherein reactor (b) is continuous with reactor (a), reactor (d) is continuous with reactor (c), and the paired reactor formed by reactors (a) and (b) is connected in parallel with the paired reactor formed by reactors (c) and (d).

The apparatus for producing an epoxide includes a reactor for treating to remove at least a portion of the haloketone formed in the apparatus.

The conditions of step (c) may be those described in application WO 2005/054167 and in application EP 05104321.4 filed on 5.20.2005 in the name of SOLVAY SA. The conditions of steps (c) and (d) are, for example, those described previously in this application.

The Process for producing an epoxide according to the present invention may be integrated into the overall Process as described in the patent application entitled "Process for preparing epoxide starting from a chlorine hydride" filed on the same date as the present application in the name of SOLVAY SA, and the contents of the above-mentioned patent application are incorporated herein by reference.

Mention is made in particular of a process for preparing an epoxide comprising at least one step of purifying the epoxide formed, at least in part by a process for dehydrochlorination of a chlorohydrin prepared at least in part by a process for chlorinating a polyhydroxylated aliphatic hydrocarbon, an ester of a polyhydroxylated aliphatic hydrocarbon or a mixture thereof.

It has been demonstrated that it is possible to increase the capacity of plants for the preparation of epoxides from fossil raw materials in an economical manner without increasing the consumption of these raw materials.

FIG. 4 shows a fourth specific apparatus profile that can be used to practice the process for producing an epoxide according to the present invention.

The distillation column (54) is fed via line (52) with the chlorohydrin originating from the chlorinated polyhydroxyaliphatic hydrocarbon reactor (51). Water is added to the chlorohydrin via line (53). A liquid stream comprising water and haloketone is continuously withdrawn from column (54) via line (55). The residue of column (54) is taken off via line (56). The basic compound is added to the residue of column (54) via line (57) and the resulting mixture is fed to reactor (59) via line (58), which may optionally be a distillation column. Steam is introduced into the bottom of reactor (59) via line (60). Gaseous steam is continuously withdrawn from reactor (59) via line (61) and fed to condenser (63). Liquid vapor is continuously withdrawn from reactor (59) via line (62). The condensed vapor (64) is fed to a phase separator (65). The separated liquid phase is returned to the top of the reactor (59) via conduit (66) to ensure reflux. The crude epoxide constitutes the separated organic phase, which is removed via line (67).

Another reactor (71), which may optionally be a distillation column, is supplied via line (69) with the chlorohydrin from the olefin hypochlorination reactor (68) and via line (70) the basic compound is added to the chlorohydrin. Steam is introduced into the bottom of reactor (71) via line (72). Gaseous vapors are continuously withdrawn from reactor (71) through line (73). Liquid vapor is continuously withdrawn from reactor (71) via line (74). The condensed vapor (76) is fed to a phase separator (77). The separated liquid phase is returned to the top of the reactor (71) via line (78) to ensure reflux. The crude epoxide constitutes the separated organic phase which is removed via line (79). The two liquid streams of the crude epoxide are collected beforehand by means of the line (80) for the purpose of purification in a conventional distillation section.

The above described process and apparatus are preferred when the epoxide is ethylene oxide, the chlorohydrin is chloroethanol, the polyhydroxylated aliphatic hydrocarbon is ethylene glycol and the olefin is ethylene.

The process and apparatus described above are more preferred when the epoxide is propylene oxide, the chlorohydrin is chloropropanol, the polyhydroxylated aliphatic hydrocarbon is propylene glycol and the alkene is propylene.

The process and apparatus described above are particularly preferred when the epoxide is glycidol, the chlorohydrin is chloropropanediol, the polyhydroxylated aliphatic hydrocarbon is glycerol and the alkene is allyl chloride.

The process and apparatus described above are particularly preferred when the epoxide is epichlorohydrin, the chlorohydrin is dichloropropanol, the polyhydroxylated aliphatic hydrocarbon is glycerol and the olefin is allyl chloride.

When the epoxide is epichlorohydrin, the process and apparatus for preparing the epoxide may be continued by the process and apparatus for preparing the epoxy resin.

The following examples are intended to illustrate the present application and are not intended to limit the invention.

Example 1

A50% by weight concentrated solution of 84g of sodium hydroxide (1.05mol) is added to a solution of 129g of 1, 3-dichloropropan-2-ol in 950ml of water. The dichloropropanol contained 3g/kg of chloroacetone. After the conversion of 1, 3-dichloropropan-2-ol was completed after 1 minute of reaction at ambient temperature, the selectivity to epichlorohydrin was 99.9% and the relative content of chloroacetone with respect to epichlorohydrin was reduced to 11 mg/kg. The selectivity to the hydrolysis product of epichlorohydrin was 0.1%.

Example 2

434.6g of a mixture of 1, 3-dichloropropan-2-ol containing 3.7g/kg of chloroacetone were added, after distillation, with 66.5g of water.

Distillation is carried out at atmospheric pressure through a thermally insulated plate column installed at the top of the apparatus so that a portion of the vapor phase is refluxed at the top of the column. The reflux ratio at the top of the column was 57%.

The results in the following table describe the composition of the various fractions collected:

40.43g of effluent were collected in six fractions, and each fraction was biphasic. The concentrations given in the table are relative to the sum of the two phases. This distillation makes it possible to remove 60% of the chloroacetone initially present, while the total loss of 1, 3-dichloropropan-2-ol in the effluent is limited to 1.8%.

Claims (22)

1. Process for the preparation of an epoxide, wherein a halogenated ketone is formed as a by-product and which comprises at least one treatment to remove at least part of the halogenated ketone formed, wherein the epoxide is epichlorohydrin.

2. The process of claim 1, wherein the epoxide is prepared by dehydrochlorination of a chlorohydrin, wherein the chlorohydrin is dichloropropanol.

3. The process according to claim 2, wherein at least a portion of the chlorohydrin is prepared by chlorinating a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon, or a mixture thereof, the multihydroxylated-aliphatic hydrocarbon being glycerol.

4. The process according to claim 3, wherein the polyhydroxylated aliphatic hydrocarbon is obtained starting from a renewable raw material.

5. The process according to any one of claims 2 to 4, wherein the treatment to remove at least part of the halogenated ketones formed is carried out during the dehydrochlorination.

6. The process according to any one of claims 2 to 5, wherein the dehydrochlorination is carried out by treating the chlorohydrin with a basic compound selected from NaOH, Ca (OH)₂Aqueous suspensions or solutions of (a), purified alkaline salt solutions and mixtures thereof.

7. The process according to any one of claims 2 to 6, wherein the halogenated ketone is present in the chlorohydrin, the treatment to remove at least part of the halogenated ketone comprising distillation, evaporation and/or stripping in the presence of water being carried out before the dehydrochlorination and being capable of removing a fraction consisting essentially of water and halogenated ketone and recovering the chlorohydrin having a reduced content of halogenated ketone.

8. The method according to claim 7, wherein after the treatment, the content of the halogenated ketone in the chlorohydrin is 0.1 wt% or less and 0.0001 wt% or more.

9. The process of any one of claims 2-8, wherein the dehydrochlorination is conducted in a batch or continuous manner at a reactant residence time or duration of 0.1s or more to 2h or less, a temperature of at least 0 ℃ of not more than 140 ℃, and a pressure of at least 0.8 bar absolute of not more than 25 bar absolute.

10. A process for preparing an epoxide comprising:

(a) a step of preparing a chlorohydrin by hypochlorating an olefin,

(b) a step for preparing the chlorohydrin by chlorinating a polyhydroxylated aliphatic hydrocarbon, said step being carried out in parallel with step (a),

(c) a conventional dehydrochlorination step in which the chlorohydrins obtained in steps (a) and (b) are used, and

(d) a treatment step for removing at least part of the halogenated ketones formed in the process,

wherein the epoxide is epichlorohydrin, the chlorohydrin is dichloropropanol, and the polyhydroxylated aliphatic hydrocarbon is glycerol.

11. A process for the preparation of an epoxide according to claim 10 wherein in step (c) a mixture of the chlorohydrins obtained in steps (a) and (b) is used.

12. The process for the preparation of epoxides as claimed in claim 10 wherein the chlorohydrin, dichloropropanol, obtained in step (a) or in step (b) is used in step (c) alternatively or simultaneously.

13. A process for preparing an epoxide comprising:

(a) a step of preparing a chlorohydrin by hypochlorating an olefin,

(b) a step of dehydrochlorinating the chlorohydrin obtained in step (a) to produce the epoxide in a dehydrochlorination reaction mixture,

(c) a step of preparing the chlorohydrin by chlorinating a polyhydroxylated aliphatic hydrocarbon,

(d) a step of dehydrochlorinating the chlorohydrin obtained in step (c) to produce an epoxide in a dehydrochlorination reaction mixture, and

(e) a step of separating the epoxide from the dehydrochlorination reaction mixture, in which the dehydrochlorination reaction mixture containing the epoxide obtained in steps (b) and (d) is used,

(f) a treatment step for removing at least part of the halogenated ketones formed in the process,

and wherein step (b) is subsequent to step (a) and step (d) is subsequent to step (c) and the paired steps consisting of steps (a) and (b) are in parallel with the paired steps consisting of steps (c) and (d), and

wherein the epoxide is epichlorohydrin, the chlorohydrin is dichloropropanol, and the polyhydroxylated aliphatic hydrocarbon is glycerol.

14. A process for the preparation of an epoxide according to claim 13 wherein in step (e) a mixture of the epoxides obtained in steps (b) and (d) is used.

15. A process for the preparation of an epoxide according to claim 13 wherein the epoxide obtained in step (b) or in step (d) is used in step (e) alternatively or simultaneously.

16. The process of any one of claims 1 to 15, wherein the haloketone is chloroacetone.

17. The method according to any one of claims 3 to 16, wherein the polyhydroxylated aliphatic hydrocarbon is glycerol obtained during the production of biodiesel or during the conversion of animal or vegetable oils and fats, said conversion being selected from saponification, transesterification or hydrolysis reactions.

18. The method of claim 17, wherein the transesterification reaction is carried out in the presence of a heterogeneous catalyst.

19. An apparatus for producing an epoxide, comprising:

(a) a reactor for hypochlorating olefins, from which reactor a reaction mixture containing chlorohydrins is discharged,

(b) a reactor for chlorinating polyhydroxylated aliphatic hydrocarbons, the reaction mixture containing the chlorohydrin being discharged from the reactor, and

(c) a reactor for dehydrochlorination fed with the reaction mixture produced from reactor (a) and from reactor (b), and

(d) a reactor for treatment to remove at least part of the halogenated ketones formed in the apparatus,

wherein the epoxide is epichlorohydrin, the chlorohydrin is dichloropropanol, and the polyhydroxylated aliphatic hydrocarbon is glycerol.

20. An apparatus for producing an epoxide, comprising:

(a) a reactor for hypochlorating olefins, from which reactor a reaction mixture containing chlorohydrins is discharged,

(b) a reactor for dehydrochlorination to which the reaction mixture produced from the reactor (a) is supplied and from which a reaction mixture containing the epoxide is discharged,

(c) a reactor for chlorinating polyhydroxylated aliphatic hydrocarbons, from which reactor a reaction mixture containing the chlorohydrin is discharged,

(d) a reactor for dehydrochlorination supplied with the reaction mixture produced from step (b) and from which a reaction mixture containing the epoxide is discharged, and

(e) a separator supplied with the reaction mixture discharged from step (b) and discharged from step (d), and

(f) a reactor for treatment to remove at least part of the halogenated ketones formed in the apparatus,

and wherein reactor (b) is connected to reactor (a) and reactor (d) is connected to reactor (c) and the reactor pair consisting of reactors (a) and (b) is connected in parallel to the reactor pair consisting of reactors (c) and (d),

wherein the epoxide is epichlorohydrin, the chlorohydrin is dichloropropanol, the olefin is allyl chloride, and the polyhydroxylated aliphatic hydrocarbon is glycerol.

21. A process for preparing an epoxy resin, comprising providing epichlorohydrin, wherein a halogenated ketone contained in the epichlorohydrin as a raw material is at least 0.0001% by weight and 0.01% by weight or less of an epoxide.

22. A process for preparing an epoxy resin according to claim 21 wherein the epichlorohydrin is obtained by a process according to any one of claims 1 to 18.