CN1993308A - Process for the production of chlorohydrins from polyhydroxyaliphatic hydrocarbons and/or their esters in the presence of metal salts - Google Patents

Abstract

A process for the production of a chlorohydrin by reaction between a multihydroxylated-aliphatic hydrocarbon, an ester of a multihydroxylated-aliphatic hydrocarbon, or a mixture thereof, and a chlorinating agent, according to which 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 to remove at least part of the metal salt.

Description

Process for the production of chlorohydrins from polyhydroxyaliphatic hydrocarbons and/or their esters in the presence of metal salts

This patent application claims the benefit of patent application FR05.05120 and patent application EP 05104321.4 filed on May 20, 2005, and U.S. provisional patent applications 60/734659, 60/734627, 60/734657, filed on November 8, 2005 , 60/734658, 60/734635, 60/734634, 60/734637 and 60/734636, the contents of which are incorporated herein by reference.

The present invention relates to a method for producing an organic substance, more particularly to a method for producing chlorohydrins.

Natural petrochemical resources such as oil and natural gas are known to be limited from the earth. These resources are currently used for the production of fuels and as starting products for the production of a large number of useful organic compounds, such as monomers or reactants for the production of plastics, such as ethylene oxide, chlorohydrin (see, for example, K. Weissermel and H.-J. Arpe in Industrial Organic Chemistry, Third Completely Revised Edition, VCH Editor, 1997, page 149), propylene oxide and monochloropropanol (see, for example, K. Weissermel and H.-J. Arpe in Industrial Organic Chemistry, Third Completely Revised Edition, VCH Editor, 1997, page 275), epichlorohydrin or dichloropropane (see, for example, Ullmann's Encyclopedia of Industrial Chemistry, 5.ed., Vol.A9, p.539-540). Documents Documents Chemistry and Industry, November 20, 1931, Part III, pages 949 to 954, and November 27, 1931, Part III, pages 970 to 975 describe a method for synthesis from glycerol and hydrochloric acid in the presence of acetic acid as a catalyst Dichloropropanol method.

According to known processes for the production of chlorohydrins, the product is usually obtained in the form of a highly diluted aqueous solution having a titer of 5 to 15% by weight. Its subsequent purification is very expensive. Furthermore, the main isomer obtained according to such a method is 2,3-dichloropropan-1-ol.

It is desirable to find uses and methods which make it possible to reduce the consumption of natural petrochemical resources, especially the uses mentioned above.

It is also desirable to find methods for reusing by-products of other production processes so that the total amount of by-products that must be eliminated or destroyed is minimized.

It is also desirable to find methods for minimizing the expense of separation operations associated with highly dilute aqueous solutions.

Accordingly, the present invention relates to a process for the production of chlorohydrins by reaction between polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof and chlorinating agents, according to which polyhydroxy aliphatic hydrocarbons used , esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof containing at least one solid or dissolved metal salt, the process comprising a separation operation to remove at least a portion of the metal salt.

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

Polyhydroxyaliphatic hydrocarbons bearing a hydroxyl function (OH) cannot have more than one OH group per carbon atom and must be sp3 hybridized. The carbon atom bearing the OH group can be primary, secondary or tertiary. The polyhydroxy aliphatic hydrocarbons used in the present invention must contain at least two sp3 hybridized carbon atoms each bearing an OH group. The polyhydroxy aliphatic hydrocarbons include any hydrocarbon containing dimethionol (1,2-diol) or dimethionol (1,2,3-triol), including linked or adjacent higher orderings of these repeating units . The definition of polyhydroxyaliphatic also includes, for example, one or more 1,3-, 1,4-, 1,5- and 1,6-diol functional groups. The polyhydroxy aliphatic hydrocarbon may also be a polymer such as polyvinyl alcohol. Gem diols, for example, are excluded from this class of polyhydroxy aliphatic hydrocarbons.

It should be understood that the polyhydroxy aliphatic hydrocarbon may contain aromatic moieties or heteroatoms, including such heteroatoms as halogen, sulfur, phosphorus, nitrogen, oxygen, silicon and boron, and mixtures thereof.

Polyhydroxy aliphatic hydrocarbons that can 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- Propylene glycol (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 polyhydroxy aliphatic hydrocarbons for use in the present invention include, for example, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2,3-propanetriol, and mixtures thereof. More preferably, the polyhydroxy aliphatic hydrocarbons used in the present invention include, for example, 1,2-ethanediol, 1,2-propanediol, chloropropanediol and 1,2,3-propanetriol, and any mixtures thereof. Most preferred is 1,2,3-propanetriol.

Esters of polyhydroxyaliphatic hydrocarbons may be present in polyhydroxyaliphatic hydrocarbons and/or may be produced during the production of chlorohydrins according to the invention and/or may be produced prior to the production of chlorohydrins. Examples of esters of polyhydroxy aliphatic hydrocarbons include: ethylene glycol monoacetate, propylene glycol monoacetate, glyceryl monoacetate, glyceryl monostearate, glyceryl diacetate, and mixtures thereof.

The term "chlorohydrin" refers to a compound containing at least one hydroxyl group and at least one chlorine atom attached to different saturated carbon atoms. Chlorohydrins containing at least two hydroxyl groups are also polyhydroxy aliphatic hydrocarbons. Accordingly, the starting substances and the products of the present invention may each be chlorohydrins. In this case, the product chlorohydrins are more deeply chlorinated than the starting chlorohydrins, in other words, the product chlorohydrins have more chlorine atoms and fewer hydroxyl groups than the starting chlorohydrins . Preferred chlorohydrins are eg chloroethanol, chloropropanol, chloropropanediol and dichloropropanol, with dichloropropanol being most preferred. Particularly preferred chlorohydrins are 2-chloroethanol, 1-chloropropan-2-ol, 2-chloropropan-1-ol, 1-chloropropan-2,3-diol, 2-chloropropan-1,3 -Diols, 1,3-dichloropropan-2-ol, 2,3-dichloropropan-1-ol and mixtures thereof.

The polyhydroxy aliphatic hydrocarbon may be a synthetic polyhydroxy aliphatic hydrocarbon, a polyhydroxy aliphatic hydrocarbon obtained from renewable raw materials, or a mixture thereof. Preferably, the polyhydroxyaliphatic hydrocarbons used in the process according to the invention are at least partly produced from renewable raw materials. The same references (or considerations) apply to esters of polyhydroxyaliphatic hydrocarbons, or mixtures of esters of polyhydroxyaliphatic hydrocarbons and polyhydroxyaliphatic hydrocarbons.

The expression "synthetic" means that the polyhydroxy aliphatic hydrocarbons are obtained from fossil raw materials. Among them, fossil raw materials refer to materials obtained from natural petrochemical raw materials such as petroleum, natural gas, and coal. Preferred among these materials are organic compounds containing two and three carbon atoms. When the chlorohydrin is dichloropropanol or chloropropanediol, allyl chloride, allyl alcohol and "synthetic" glycerol are more preferred. Wherein "synthetic" glycerol refers to glycerol obtained from petrochemical raw materials. Ethylene and "synthetic" glycols are more preferred when the chlorohydrin is chlorohydrin. Wherein "synthetic" ethylene glycol refers to ethylene glycol obtained from petrochemical raw materials. Propylene and "synthetic" propylene glycol are more preferred when the chlorohydrin is chloropropanol. Wherein "synthetic" propylene glycol refers to propylene glycol obtained from petrochemical raw materials. The same references (or considerations) apply to esters of polyhydroxyaliphatic hydrocarbons, or mixtures of esters of polyhydroxyaliphatic hydrocarbons and polyhydroxyaliphatic hydrocarbons.

Among them, renewable raw materials refer to materials obtained by processing renewable raw materials. Preferred among these materials are natural ethylene glycol, natural propylene glycol and natural glycerin. "Natural" ethylene glycol, propylene glycol, and glycerol can be obtained, for example, by thermochemically converting sugars that can be processed from biomass, 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 Biomass Program, July 2003, pages 49, 52 to 56. One of these methods is, for example, catalytic hydrogenolysis of sorbitol obtained by thermochemical conversion of glucose. Another method It is, for example, xylitol obtained by hydrogenation of xylose obtained by catalytic hydrogenolysis, which can be obtained, for example, by hydrolysis of hemicellulose present in corn fiber.

The expression "glycerol obtained from renewable raw materials" or "natural glycerol" refers in particular to glycerol obtained during the production of biodiesel, or during the transformation of plants or animals in common reactions such as saponification, transesterification (or transesterification) or hydrolysis. Glycerin obtained when fat or oil.

Among the oils that may be used in this application, it may be mentioned all existing oils such as corn oil, sunflower (seed) oil, old or new rapeseed oil, babassu oil, coconut oil, kale oil, palm oil , castor and cotton (seed) oils, peanut oil, soybean oil, linseed oil and crabgrass oil, and all oils derived from sunflower or rapeseed crops obtained through genetic modification or hybridization. You can even use old frying oil, various animal oils such as fish oil, tallow, lard, and even dismembered fat. Among the oils used, it is also possible to refer to oils which have been partially modified, for example by polymerisation or oligomerisation, for example "linseed oil", sunflower oil and flowering vegetable oil.

A particularly suitable glycerol is obtained when converting animal fats. Another particularly suitable glycerol is available in the production of biodiesel. Yet another particularly suitable glycerol can be obtained when converting vegetable or animal fats or oils by transesterification (or transesterification) in the presence of heterogeneous catalysts, as described in application documents FR 2752242, FR 2869612 and FR 2869613 of. More specifically, the heterogeneous catalyst is selected 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 aluminum, and the heterogeneous The catalyst is used in the form of a fixed bed. In the method according to the present invention, glycerol may be as described in the application titled "Process for preparing a chlorohydrin by chlorinating a polyhydroxylated aliphatic hydrocarbon" filed on the same day as this application in the name of SOLVAY SA, and the content of the above application incorporated herein by reference.

Mention is made in particular of a process for the production of chlorohydrins in which polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or Their mixture reacts with chlorinating agents.

In contrast, "synthetic polyhydroxyaliphatic hydrocarbons" are generally obtained from petrochemical sources. The same references (or considerations) apply to esters of polyhydroxyaliphatic hydrocarbons, or mixtures of esters of polyhydroxyaliphatic hydrocarbons and polyhydroxyaliphatic hydrocarbons.

In the process for preparing epoxides according to the present invention, the polyhydroxyaliphatic hydrocarbon used may be a crude product of polyhydroxyaliphatic hydrocarbon or a purified product of polyhydroxyaliphatic hydrocarbon. A "crude" product of polyhydroxy aliphatic hydrocarbons is one that has not undergone any treatment after its production. A "purified" product of polyhydroxy aliphatic hydrocarbons is one that has undergone at least one treatment after its production. When the polyhydroxyaliphatic hydrocarbon is a crude product obtained from renewable raw materials, it may contain, for example, water in addition to metal salts. The metal salt is especially a metal chloride, which is preferably selected from NaCl and KCl. The metal salt may also be selected from metal sulphates such as sodium sulphate and potassium sulphate. The polyhydroxyaliphatic hydrocarbons used in the process according to the invention contain at least one solid or dissolved metal salt, preferably selected from sodium chloride, potassium chloride, sodium sulfate and potassium sulfate. The polyhydroxy aliphatic hydrocarbons used in the process according to the invention generally contain a metal salt content of at least 0.5% by weight, preferably greater than or equal to about 1% by weight, more preferably greater than or equal to about 2% by weight, most preferably greater than or equal to about 3% by weight %. The metal salt content is generally up to 15% by weight, preferably less than or equal to about 10% by weight, more preferably less than or equal to about 7.5% by weight, most preferably less than or equal to about 5% by weight. The same references (or considerations) apply to esters of polyhydroxyaliphatic hydrocarbons, or mixtures of esters of polyhydroxyaliphatic hydrocarbons and polyhydroxyaliphatic hydrocarbons.

In the process according to the invention, the crude product of polyhydroxy aliphatic hydrocarbons may contain organic impurities such as carbonyl compounds, especially aldehydes, fatty acids, salts of fatty acids or esters of fatty acids, such as especially polyhydroxy aliphatic hydrocarbons with fatty acids optionally in combination with monoester or polyester in aqueous compositions. When the polyhydroxy aliphatic hydrocarbon is glycerol, the preferred fatty acids are saturated and unsaturated fatty acids containing more than 12 carbon atoms, such as oleic acid, linoleic acid and linolenic acid. These acids are produced, for example, during the conversion of rapeseed oil by saponification, transesterification (ester exchange) or hydrolysis reactions. Preferred fatty acid esters are methyl esters.

In the process according to the invention, the crude product generally contains up to 10% by weight of organic impurities, frequently 8% of organic impurities. Frequently, the crude product contains up to 6% by weight of organic impurities. Preferably, it contains at most 2% by weight of organic impurities. Most preferably, it contains up to 1% by weight of organic impurities. Typically, the organic impurities consist essentially of fatty acids and their derivatives.

Furthermore, the present application relates to a process for the production of chlorohydrins, according to which polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof containing up to 8% by weight of organic impurities are subjected to a reaction with a chlorinating agent reaction.

Surprisingly, studies have found that the use of organic impurities having a high content has essentially no effect on the reactions for carrying out the process of the invention. Optional by-products from this organic impurity can be easily removed from the reaction mixture, for example (if applicable) as in patent application WO 2005/054167, page 17, line 33 to 18, filed in the name of SOLVAY SA What is described in line 33 on page 24 and line 8 on page 25 to line 10 on page 25 is achieved by controlling the ratio of the cleaning material, the content of the above-mentioned application is hereby incorporated by reference.

In the process according to the invention, the crude polyhydroxyaliphatic hydrocarbon product generally contains at least 40% by weight of polyhydroxyaliphatic hydrocarbons. Frequently, the crude product contains at least 50% by weight of polyhydroxy aliphatic hydrocarbons. Preferably, it contains at least 70% by weight of polyhydroxy aliphatic hydrocarbons. Frequently, the crude product contains up to 99% by weight of polyhydroxyaliphatic hydrocarbons. Typically, it contains up to 95% by weight of polyhydroxy aliphatic hydrocarbons.

In the process according to the invention, the crude polyhydroxyaliphatic hydrocarbon generally contains at least 5% by weight of water, or in the absence of other compounds other than water and polyhydroxyaliphatic hydrocarbons, at least 1% by weight of water. In the process according to the invention, the crude polyhydroxyaliphatic hydrocarbon generally contains up to 50% by weight of water, or in the absence of other compounds other than water and polyhydroxyaliphatic hydrocarbons, up to 60% by weight of water. Frequently, the crude polyhydroxyaliphatic hydrocarbon contains up to 30% by weight of water, preferably up to 21% by weight of water.

In another embodiment, the crude polyhydroxy aliphatic hydrocarbon product contains up to 89% by weight polyhydroxy aliphatic hydrocarbon. In this example, the crude product of polyhydroxy aliphatic hydrocarbons contains up to 85% by weight of polyhydroxy aliphatic hydrocarbons. In this example, the crude polyhydroxy aliphatic hydrocarbon typically contains at least 10% by weight water, and often at least 14% water.

The crude polyhydroxy aliphatic hydrocarbon has a metal salt content of at least 0.5% by weight, preferably greater than or equal to about 1%, and more preferably greater than or equal to about 1.5%. The crude polyhydroxy aliphatic hydrocarbon has a metal salt content of up to 15% by weight, preferably less than or equal to 12%, and more preferably less than or equal to about 7.5%.

The separation operation according to the invention is particularly preferably applied in the production of chlorinated compounds starting from polyhydroxyaliphatic hydrocarbons, especially in the production of chlorohydrins and epoxides. Surprisingly, the separation operation according to the invention makes it possible to obtain these compounds economically from renewable raw materials.

The term "epoxide" is used to describe a compound containing at least one oxygen bridged by a carbon-carbon bond. Generally, 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 atoms and halogens. Preferred epoxides are ethylene oxide, propylene oxide, glycidol and epichlorohydrin.

The present invention therefore also relates in particular to a process for the production of chlorinated organic compounds according to which polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof obtained from renewable raw materials are used, the polyhydroxyaliphatic hydrocarbons used are The hydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof contain at least one solid or dissolved metal salt, and the process includes a separation operation to remove at least a portion of the metal salt.

It should be understood that the production process described herein can also be carried out using common polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof, and is not limited to the preferred use of polyhydroxy aliphatic hydrocarbons obtained from renewable raw materials , esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof.

In the following, the expression "chlorinated compounds" is to be understood as "chlorohydrins". Preferred chlorohydrins are eg chlorohydrin, chloropropanol, chloropropanediol and dichloropropanol, with dichloropropanol being most preferred.

The term "chloroethanol" is used to denote mixtures including 2-chloroethanol.

The term "chloropropanol" is intended to include mixtures of 1-chloropropan-2-ol and 2-chloropropan-1-ol.

The term "chloropropanediol" is intended to include mixtures of 1-chloropropan-2,3-diol and 2,3-dichloropropan-1-ol.

In the process for producing chlorohydrins according to the present invention, the chlorinating agent may be hydrogen chloride and/or hydrogen chloride as described in page 4, line 30 to page 6, line 2 of patent application WO 2005/054167 of SOLVAY SA or hydrochloric acid. Chlorinating agents mentioned in particular may be gaseous hydrogen chloride, aqueous hydrochloric acid or a combination of both. Hydrogen chloride can be obtained from the pyrolysis of organic chlorides such as from the production of vinyl chloride, from the production of 4,4-methylene dipropyl diisocyanate (MDI) or tolyl diisocyanate (TDI), from metal cleaning process, or from the reaction of mineral acids such as sulfuric or phosphoric acid with metal chlorides such as sodium chloride, potassium chloride or calcium chloride.

In the process for the production of chlorohydrins according to the invention, the chlorinating agent can be aqueous hydrogen chloride or preferably anhydrous hydrogen chloride, originating from a plant for the production of allyl chloride and/or a plant for the production of methyl chloride and/or or a chlorination plant and/or a high temperature oxidation plant as disclosed in the application titled "Process formanufacturing a chlorohydrin by reaction between amulti-hydroxylated aliphatic hydrocarbon and a chlorinating agent" filed on the same date as this application in the name of SOLVAY SA, and The content of the above application is hereby incorporated by reference.

Particular mention is made of a process for the preparation of chlorohydrins from polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof and a chlorinating agent containing at least one of the following compounds: nitrogen (gas), oxygen (gas ), hydrogen (gas), chlorine (gas), hydrocarbons (or hydrocarbons), organic halides, organic oxides, and metals.

Particular mention is made of a hydrocarbon selected from aromatic hydrocarbons, saturated and unsaturated aliphatic hydrocarbons or mixtures thereof.

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

Particular mention is made of one selected from the group consisting of methyl chloride, ethyl chloride, chloropropane, chlorobutane, vinyl chloride, vinylidene chloride, monochloropropene, perchloroethylene, trichloroethylene, chloroprene, chlorobenzene and their Mixtures of organic chlorides and organic halides.

Particular mention is made of an organic halide of an organic fluoride selected from the group consisting of fluoromethane, fluoroethane, vinyl fluoride, vinylidene fluoride and mixtures thereof.

Particular mention is made of an organic oxide selected from the group consisting of alcohols, chlorohydrins, chloroethers and mixtures thereof.

Particular mention is made of metals selected from the group consisting of 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 at least a part of the chlorinating agent is obtained from a process for the production of allyl chloride and/or from a process for the production of methyl chloride and/or from a process of chlorination and/or from a process at high temperature Obtained in the process of oxidation of chloride at or equal to 800°C.

In a more preferred embodiment, the chlorinating agent does not contain gaseous hydrogen chloride.

The process for the production of chlorohydrins according to the invention can be carried out in a reactor as specifically disclosed on page 6, lines 3 to 23 of the application WO 2005/054167 of SOLVAY SA.

Particular mention is made of a device manufactured or coated from a material resistant to chlorinating agents, especially hydrogen chloride, under the reaction conditions. Mention is made more particularly of a device made of enamelled steel or tantalum. The process for the production of chlorohydrins according to the invention can be carried out in a device manufactured or coated with a material resistant to chlorinating agents, as in the title "Process for manufacturing a chlorohydrin" filed in the name of SOLVAY SA on the same day as this application. in equipments resisting to corrosion", the contents of which are hereby incorporated by reference.

Particular mention is made of a process for the production of chlorohydrins comprising a step of reacting a polyhydroxy aliphatic hydrocarbon, an ester of a polyhydroxy aliphatic hydrocarbon, or a mixture thereof with a chlorinating agent comprising hydrogen chloride, and at least one other step of The reacting steps are carried out in equipment fabricated or coated (or covered) with a material resistant to the chlorinating agent under the conditions of these steps. Mention is made more particularly of metallic materials such as enamelled steel, gold and tantalum, and of non-metallic materials such as high-density polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, perfluoroalkoxyalkanes and polyperfluoropropylene vinyl ethers, polysulfones and polysulfides (or polysulfides), graphite, and impregnated graphite.

The process for the production of chlorohydrins according to the present invention can be carried out in a reaction medium as described in the application titled "Continuous process for the manufacture of chlorohydrins" filed on the same day as this application in the name of SOLVAY SA, and the above application The contents of are incorporated herein by reference.

Particular mention is made of a continuous process for the production of chlorohydrins in which polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof are reacted with chlorinating agents and organic acids in a liquid reaction medium, the stability of which medium The state composition (or stable state composition) includes polyhydroxy aliphatic hydrocarbons and esters of polyhydroxy aliphatic hydrocarbons, and the total content of polyhydroxy aliphatic hydrocarbons and esters of polyhydroxy aliphatic hydrocarbons expressed in moles of polyhydroxy aliphatic hydrocarbons is greater than 1.1 mol% and Less than or equal to 30 mol%, the percentage expressed relative to the organic portion of the liquid reaction medium.

The organic fraction of the liquid medium is defined as the sum of the organic compounds of the liquid medium, that is to say, said compound molecules contain at least one carbon atom.

In the process for the production of chlorohydrins according to the present invention, the reaction of the polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or their mixtures with a chlorinating agent can be described e.g. on page 6 of patent application WO 2005/054167 of SOLVAY SA in the presence of a catalyst as specifically disclosed in line 28 to page 8, line 5. Particular mention is made of a catalyst based on carboxylic acids or carboxylic acid derivatives having an atmospheric boiling point higher than or equal to 200° C., especially adipic acid and adipic acid derivatives.

In the process for the production of chlorohydrins according to the present invention, the reaction of the polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or their mixtures with a chlorinating agent can be described, for example, on page 8 of patent application WO 2005/054167 of SOLVAY SA Conducted at the temperatures, pressures and residence times specifically disclosed in line 6 to line 10 on page 10.

Particular mention is made of temperatures of at least 20° C. and at most 160° C., pressures of at least 0.3 bar and at most 100 bar, and residence times of at least 1 h and at most 50 h.

In the process for the production of chlorohydrins according to the present invention, the reaction of the polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or their mixtures with chlorinating agents can be described e.g. on page 11 of patent application WO 2005/054167 of SOLVAY SA in the presence of the solvent specifically disclosed in lines 12 to 36.

Particular mention is made of chlorinated organic solvents such as alcohols, ketones, esters or ethers, such as chloroethanols, chloropropanols, 3-chloropropanediols, dichloropropanols, dioxanes, phenols, cresols and 3-chloropropanediols and Anhydrous solvents immiscible with the polyhydroxy aliphatic hydrocarbon such as mixtures of dichloropropanol, or organic solvents of heavy reaction products such as at least partially chlorinated and/or esterified oligomers of the polyhydroxy aliphatic hydrocarbon solvent.

In the process for the production of chlorohydrins according to the present invention, the reaction between the polyhydroxy aliphatic hydrocarbon, the ester of polyhydroxy aliphatic hydrocarbon or their mixture and the chlorinating agent can be described in the name as filed under the name of SOLVAY SA on the same date as this application. It is carried out in the presence of a liquid phase containing heavy compounds as described in the patent application "Process for manufacturing a chlorohydrin in a liquid phase", the content of which is incorporated herein by reference.

Particular mention is made of a process for the production of chlorohydrins in which polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof are reacted with a chlorinating agent in the presence of a liquid phase containing heavy compounds in absolute The boiling temperature at a pressure of 1 bar is at least 15° C. higher than the boiling temperature of the chlorohydrin at an absolute pressure of 1 bar.

The process for producing chlorohydrins according to the invention can be carried out batchwise or continuously. Especially preferred is the continuous mode.

In the process for producing chlorohydrins according to the invention, the reaction between the polyhydroxyaliphatic hydrocarbon, the ester of polyhydroxyaliphatic hydrocarbon or their mixture and the chlorinating agent is preferably carried out in a liquid reaction medium. The liquid reaction medium can be a single-phase medium or a multi-phase medium.

The liquid reaction medium consists of all dissolved or dispersed solid compounds, dissolved or dispersed gases and dissolved or dispersed liquids at the reaction temperature.

The reaction medium includes reactants, catalysts, solvents, impurities present in the reactants, catalysts and solvents, reaction intermediates, reaction products and reaction by-products.

Wherein reactant, it refers to this polyhydroxy aliphatic hydrocarbon, the ester of polyhydroxy aliphatic hydrocarbon and chlorinating agent.

Among the impurities present in polyhydroxyaliphatic hydrocarbons, mention may be made of carboxylic acids, carboxylate salts, esters of fatty acids with polyhydroxyaliphatic hydrocarbons, esters of fatty acids with alcohols used in the transesterification process, and substances such as alkali metals or alkaline earth Inorganic salts such as metal chlorides (or hydrochlorides) and sulfates.

When the polyhydroxy aliphatic hydrocarbon is glycerol, the impurities in glycerol can be mentioned carboxylic acids, carboxylic acid salts, fatty acid esters such as monoglycerides, diglycerides and triglycerides, fatty acids and esters used for esters esters formed by alcohols during radical transfer, and inorganic salts such as alkali or alkaline earth metal chlorides and sulfates.

Among the reaction intermediates, mention may be made of the monochlorohydrins of the polyhydroxyaliphatic hydrocarbons and their esters and/or polyesters, the esters and/or polyesters of the polyhydroxyaliphatic hydrocarbons and the esters of the polychlorohydrins.

When the chlorohydrin is dichloropropanol, it can mention monochlorohydrin of glycerol and its ester and/or polyester, ester of glycerol and/or polyester and dichloropropanol in the reaction intermediate. ester.

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

Wherein the reaction product is used to refer to chlorohydrins and water. The water may be the water formed in the chlorination reaction and/or the water introduced into the process.

Among the by-products, mention may be made, for example, of partially chlorinated and/or esterified oligomers of the polyhydroxyaliphatic hydrocarbons.

When the polyhydroxyaliphatic hydrocarbon is glycerol, mention may be made, among the by-products, of partially chlorinated and/or esterified oligomers of glycerol.

The reaction intermediates and by-products may be formed in different steps of the process, for example during the production of the chlorohydrins or in the isolation steps of the chlorohydrins.

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

In the process according to the invention, the separation of chlorohydrins and other compounds from the reaction medium can be carried out in the same way as in the patent application WO 2005/054167 of SOLVAY SA from page 12, line 1 to page 16, line 35 and page 18. The method disclosed in lines 6 to 13 is performed. These other compounds are those already mentioned above and include unconsumed reactants, impurities present in reactants, catalysts and solvents, catalysts, solvents, reaction intermediates, water and reaction by-products.

In the process according to the invention, the separation and treatment of other compounds in the reaction medium can be carried out as disclosed in page 18, lines 6 to 13 of patent application WO 2005/054167 of SOLVAY SA.

Particular mention is made of the separation of water/chlorohydrins/chlorinating agent mixtures by azeotropic distillation with minimal loss of chlorinating agent followed by precipitation (or decantation).

In the process for the production of chlorohydrins according to the present invention, the separation of chlorohydrins from other compounds from the reaction medium can be done as in the patent application entitled "Process for manufacturing a chlorohydrin" filed on the same day as this application in the name of SOLVAY SA The same method as disclosed in , and the content of the above-mentioned application is hereby incorporated by reference.

Particular mention is made of a process for the preparation of chlorohydrins comprising the steps of: (a) reacting polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof with chlorinating agents and organic acids to obtain compounds containing the a mixture of chlorohydrins and esters of said chlorohydrins, (b) subjecting at least part of the mixture obtained in step (a) to one or more treatments in a step subsequent to step (a), and (c) in step ( a) The polyhydroxy aliphatic hydrocarbon is added in at least one subsequent step so as to react with the chlorohydrin ester at a temperature of at least 20° C. so as to at least partially form an ester of the polyhydroxy aliphatic hydrocarbon. More particular mention is made of a process wherein the polyhydroxy aliphatic hydrocarbon is glycerol and the chlorohydrin is dichloropropanol.

In the method for producing chlorohydrin according to the present invention, the separation of chlorohydrin and other compounds from the reaction medium can be carried out in the name "Process for manufacturing a chlorohydrin from a multi-hydroxylated aliphatic hydrocarbon" filed in the name of SOLVAY SA on the same date as this application The same method as described in the application of , and the content of the above application is incorporated herein by reference.

Particular mention is made of a method for the production of chlorohydrins by reaction of polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof with chlorinating agents in a reactor with one or more liquid stream feeds A process wherein the liquid stream contains less than 50% by weight of polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons, or mixtures thereof, relative to the total weight of all liquid streams introduced into the reactor. Mention is more particularly made of a process comprising the steps of: (a) reacting a polyhydroxy aliphatic hydrocarbon, an ester of a polyhydroxy aliphatic hydrocarbon or a mixture thereof with a chlorinating agent so as to obtain at least one compound containing chlorohydrins, water and a chlorinating agent A medium, (b) taking at least a part of the mixture obtained in reaction step (a), and (c) subjecting the part (or fraction) taken in step (b) to distillation and/or stripping operations, wherein adding The polyhydroxy aliphatic hydrocarbon is so as to separate the mixture containing water and chlorohydrins from the fraction (or fraction) withdrawn in step (b), and it exhibits a reduced Chlorinating agent content.

In the process for the production of chlorohydrins according to the present invention, the separation of chlorohydrins and other compounds from the reaction medium can be carried out using the patent titled "Process for converting multi-hydroxylated aliphatichydrocarbons into chlrohydrins" filed in the name of SOLVAY SA on the same date as this application The same procedure was carried out as described in the application, the contents of which are incorporated herein by reference.

Particular mention is made of a process for the production of chlorohydrins comprising the steps of: (a) reacting a polyhydroxy aliphatic hydrocarbon, an ester of a polyhydroxy aliphatic hydrocarbon, or a mixture thereof with a chlorinating agent to obtain a chlorine-containing (b) subjecting at least a part (or fraction) of the mixture obtained in step (a) to distillation and/or stripping to obtain enriched (or concentrated) organic fractions of water, chlorohydrins and esters of chlorohydrins; and (c) subjecting at least a portion of the fraction (or fraction) obtained in step (b) to a separation operation in the presence of at least one additive, thereby obtaining enriched (or concentrate) the fraction containing chlorohydrins and chlorohydrin esters and containing less than 40% by weight of water. This separation operation is more particularly settling (or decanting).

In the process according to the invention, the separation and treatment of other compounds from the reaction medium can be carried out in the patent application entitled "Process for manufacturing a chlorohydrin by chlorination of multi-hydroxylated aliphatic hydrocarbon" filed on the same day as the application in the name of SOLVAY SA The same method as described in A preferred treatment method may include subjecting a portion of the other products to high temperature oxidation.

Particular mention is made of a process for the production of chlorohydrins comprising the steps of: (a) polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons, or their The mixture of is reacted with a chlorinating agent and an organic acid to obtain a mixture containing at least chlorohydrins and by-products, (b) at least a part of the mixture obtained in step (a) is carried out in a step after step (a) One or more treatments, and (c) at least one step after step (a) is oxidation at a temperature higher than or equal to 800°C. Mention is more particularly made of a method wherein in a subsequent step a portion of the mixture obtained in step (a) is withdrawn and this portion is oxidized at a temperature higher than or equal to 800° C. during withdrawal. Particular mention is also made of a process wherein the treatment of step (b) is selected from the group consisting of settling (phase separation), filtration, centrifugation, extraction, washing, evaporation, stripping, distillation and adsorption operations, or at least two of these operations Combined separation operations.

In the process according to the invention for the production of chlorohydrins, steam stripping, especially steam stripping (or steam distillation) of the reaction medium may be carried out. The reaction medium is as defined above. The medium is preferably a liquid reaction medium (liquid phase) as defined above. When the reaction medium is a liquid phase, the expression "reaction medium" also includes a gaseous phase in equilibrium with the liquid phase. Thus in the following, the expression "reaction medium" will be used to refer ambiguously to the liquid phase in which the reaction between the polyhydroxyaliphatic hydrocarbon and the chlorinating agent takes place and to the gaseous phase in equilibrium with this liquid phase. When steam stripping of the reaction medium is carried out, a stripped fraction containing 1 to 5, sometimes 2 to 3, and preferably 1.5 to 2.5 mol/l of chlorinated organic compounds, especially chlorohydrins, can be obtained. The stripped fraction consists mainly of water and chlorohydrins.

In the process according to the invention for the production of chlorohydrins, when chlorohydrins are not completely removed from the reaction mixture by taking off fractions (or parts), at least another fraction of the reaction medium containing chlorohydrins can be removed.

In this aspect of the process for producing chlorohydrins according to the invention, generally at least one fraction containing 50 to 96% by weight of chlorohydrins and up to 50% by weight of water is recovered. Preferably, the fraction contains 75 to 99.9% by weight of chlorohydrins and 0.01 to 25% by weight of water, frequently 75 to 99% by weight of chlorohydrins and 1 to 25% by weight of water.

Recovery is preferably performed by distillation or evaporation. The other fractions obtained during this step, containing eg intermediates, optionally polyhydroxy aliphatic hydrocarbons and catalyst, may be recycled for reaction with chlorinating agents. It is also possible to isolate at least one fraction containing heavy by-products of the reaction, especially chlorinated polyhydroxy Polymers of aliphatic hydrocarbons, which can be destroyed or which can optionally be used, for example by dehydrochlorination, in a process for the production of polymers of polyhydroxy aliphatic hydrocarbons.

Distillation or evaporation is generally carried out at a temperature of at least 20°C. This temperature is often at least 60°C. It is preferably at least 70°C. Distillation or evaporation is usually carried out at a temperature of up to 180°C. This temperature is often at most 140°C.

Distillation or evaporation is generally carried out at pressures greater than 0.001 bar. This pressure is preferably greater than or equal to about 0.003 bar. Distillation or evaporation is generally carried out at a pressure of a maximum of 15 bar. The pressure is often a maximum of 10 bar. Preferably a maximum of 7 bar, more preferably a maximum of 1 bar, even more preferred a maximum of 1 bar, and most preferably a maximum of 0.1 bar.

Distillation or evaporation can be carried out with distillation columns or with evaporators, film evaporators or, alternatively, swept-wall thin-film evaporators.

Recoverable fractions of the residue can be advantageously separated therefrom by means of swept-wall thin-film evaporators equipped with internal or external condensers. An example of a chemical manipulation is the hydrolysis of residues to recover eg catalysts.

In a particular variant of the process according to the invention, when the chlorohydrin is a dichlorohydrin, the dichlorohydrin is produced according to a process comprising the following steps:

(a) a first reaction step in which the polyhydroxy aliphatic hydrocarbon is contacted with a chlorinating agent to obtain a part of the product (or a fraction of the product) comprising at least monochlorohydrin;

(b) optionally subjecting at least part of the product fraction (or part of the product) to a drying operation;

(c) introducing at least part of the optionally dried product fraction (or part of the product) into a second reaction step in which at least part of the monochlorohydrin is reacted with a chlorinating agent.

Steps (a) and (c) in this variant are preferably carried out under certain conditions and with the preferred values as described above for the process according to the invention for the production of chlorohydrins. However, it is preferred to carry out the reaction of step (a) in the presence of water, wherein the content of water is preferably from 3 to 40% by weight of the total weight of the reaction medium.

For example, step (b) may be carried out in at least one reactor of step (a) or (c) by stripping operation or using an evaporator placed on a recirculation line outside the reactor or by distillation. According to another preferred variant, the water is removed by membrane technology.

The process for producing chlorohydrins according to the invention can be carried out, for example, in a cascade of reactors, in at least one tray column or in at least one bubble column, or a combination of these reactors.

The reactor can be effectively of the type stirred by internal stirring or by recirculation pipes external to the reactor.

When heating the reaction medium in the process according to the invention, it may be done, for example, via a jacket or via internal heat exchangers. Heating can also be done by means of a heat exchanger on the recirculation line outside the reactor. Optionally, heating is performed by using a combination of a jacket and a heat exchanger on the recirculation line outside the reactor.

Especially when the process according to the invention is operated in continuous or batch feed mode, secondary reactions can lead to the accumulation of low-volatility by-products in the reactor, more or less chlorinated oligomerization of polyhydroxy aliphatic hydrocarbons thing. This accumulation leads to an incremental increase in the volume of the reaction medium, resulting in an incremental loss of production capacity, necessitating continuous or discontinuous cleaning of the reactor to maintain the volume at an adequate level. Wherein the expression "cleaning" is used to refer to taking out a fraction (or part) of the reaction medium.

If appropriate, the amount of catalyst removed during this cleaning operation can be compensated by introducing an equivalent amount of pure or purified catalyst.

The catalyst contained in the purge from the reaction mixture can be economically recycled in the reactor after the purification treatment. For example, catalysts with low solubility in water may be subjected to a hydrolytic treatment, preferably at a temperature above 30°C, preferably at least 50°C, followed by e.g. decantation (or phase separation), filtration or extraction (or extraction). Separation steps. It has been found that in the case of adipic acid, hydrolysis of the wash results in the recovery of high purity crystalline adipic acid in good yields after cooling and filtration.

Especially when the process according to the invention is operated in continuous or batch feed mode, metal salts, especially NaCl (which is optionally present in the starting materials, such as polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof, originating from renewable sources as described above) can be enriched in a reactor in which the reaction between polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof and a chlorinating agent is carried out. An increase in the metal salt content leads to the accumulation of crystallization of insoluble substances and leads to various problems related to solid matter, such as deposit formation on the reactor walls, on the agitator and on the feed and purge lines and on the valves, This insoluble material leads to an increase in the volume of the reaction mixture. Deposit formation on the reactor walls can reduce heat transfer efficiency and require increased amounts of energy to maintain the reaction temperature. Deposit formation on lines and valves can cause clogging problems. Increased amounts of solids in the reaction mixture can reduce agitation efficiency and require greater amounts of energy to achieve proper agitation. An increase in metal salt content requires a higher frequency of continuous or discontinuous cleaning, resulting in higher product loss.

Surprisingly, however, the presence of metal salts in the process according to the invention is acceptable, and it is therefore desirable to be able to remove at least a portion of the metal salts, especially NaCl, from, for example, the reaction system, thereby preventing any random contamination of the metal salts in the reaction mixture. accumulation. Such removal may suitably be carried out by subjecting at least a part (or a fraction) of the reaction mixture containing solid or dissolved metal salts to treatment (which includes at least one separation operation) to extract from said part (or fraction) remove at least a portion of the metal salts.

The separation operation may be selected from liquid/solid, liquid/liquid, liquid/gas and solid/gas separations.

The liquid/solid separation operation may be selected from decantation (precipitation or phase separation), centrifugation, filtration, adsorption and treatment with ion exchange resins. The liquid/liquid separation operation may be selected from decantation and centrifugation. The liquid/gas separation operation may be selected from stripping, evaporation and distillation.

A liquid/solid separation operation is preferred, filtration is more preferred, and filtration to remove the metal salt as a solid therein is most preferred.

In the process according to the invention, the reaction is preferably carried out in a reaction mixture and the separation operation is carried out in at least a part of the reaction mixture. The portion of the reaction mixture may be treated to remove at least one component that is not a metal salt prior to the separation operation. This treatment can be a stripping or distillation operation.

The part (or fraction) of the reaction mixture to be subjected to the isolation operation may be taken directly from the reaction mixture, especially when the reaction is carried out in the liquid phase. The portion (or fraction) of the reaction mixture to be subjected to the separation operation may also be taken from the reaction mixture and subjected to additional treatment prior to removal of the metal salt. Examples of suitable treatments are concentration operations on the liquid portion of the reaction mixture, where volatile compounds such as starting materials and reaction products, which can optionally be recovered and/or recycled to the reaction mixture, for example by stripping, Separation by distillation or evaporation to obtain a concentrated fraction (or fraction) with increased content of solids or dissolved metal salts and processed to separate the metal salts.

Thus, this separation step can be carried out as in any step of the process for the production of chlorohydrins described in the patent application WO 2005/054167 of SOLVAY SA, page 12, line 1 to page 18, line 13, e.g. After the chlorination reaction, after the step of removing the mixture of chlorohydrins and water from the reaction mixture, after the removal of the chlorohydrins by evaporation followed by distillation, after the washing of reaction by-products or after the step for recovering the catalyst from the washings After processing.

In a preferred embodiment, the portion of the metal salt-containing reaction mixture is obtained from the purge of the reactor in which the reaction takes place and is fed to at least one separation unit, for example by Adsorption, distillation, extraction, precipitation, centrifugation, filtration, and treatment with ion exchange resins are used to separate metal salts. Liquid/solid separation operations are preferred, while filtration is more preferred. The separated liquid is preferably recycled back into the reactor while the metal salt remains in the filter.

The filtration step can be carried out at a temperature generally greater than or equal to 4°C, preferably greater than or equal to 20°C, more preferably greater than or equal to 30°C, more preferably greater than or equal to 50°C, most preferably greater than or equal to 80°C. This temperature is generally lower than or equal to 150°C, preferably lower than or equal to 140°C.

The type of filtration system is non-critical and will be apparent to the skilled person having knowledge of the present invention. A description of suitable filtration systems can be found in "Perry's Chemical Engineers' Handbook, Sixth Edition, 1984, Sections 19-65 to 19-103".

For accumulation of metal salts in the filtration system, it is generally recommended to periodically regenerate the filtration unit by removing the filtered salts. Regeneration can be accomplished by any means, for example by removal of solids, especially mechanically, or by dissolution of salts. Optionally, a solids elution (or stripping) process can be incorporated into the regeneration procedure.

In one embodiment according to the invention, the metal salt is removed from the filtration system as a solid without any pretreatment.

In a first variant, the salts are removed in a suitable manner without further treatment.

In a second variant, the salt is stored in a separator tank for further processing. Further processing may include eluting the solid with a solvent and dissolving the solid with a solvent. Such processing is described in the preferred embodiments below.

In a preferred embodiment according to the invention, the metal salt is treated before it is removed from the filtration system.

Alternatively, adsorbed products and reactants such as especially catalysts and chlorohydrins and their esters can be removed by elution from metal salts, especially from NaCl, with a suitable elution solvent such as a mixture of water and chlorohydrins. Any ratio between water and chlorohydrins is suitable. Preference is given to using chlorohydrins which are saturated with water at room temperature. Particular preference is given to using a phase which results from a phase separation between chlorohydrins and water. The water content of the chlorohydrins used as the elution solvent is generally less than or equal to 20% by weight, preferably less than or equal to 15% by weight, and most preferably less than or equal to about 12% by weight. The water content in the mixture of water and chlorohydrins is generally greater than or equal to 1% by weight.

In another embodiment, the elution solvent consists essentially of chlorohydrins. In this embodiment, the water content is generally less than 1% by weight, preferably less than or equal to 0.5% by weight.

In yet another embodiment, the elution solvent is water, such as fresh water as defined above.

The elution step may be performed at a temperature generally greater than or equal to 20°C, preferably greater than or equal to 50°C, most preferably greater than or equal to 80°C. This temperature is usually less than or equal to 150°C, and preferably less than or equal to 140°C.

After elution, the solvent used to elute the metal salt can be recycled to the chlorination reactor.

Several elution steps can be performed.

In particular, after elution with chlorohydrins, the metal salt may then optionally be further eluted with an aqueous solution. The aqueous solution can come from any step of the process. Preference is given to using fresh water as defined above.

The elution step may be performed at a temperature generally greater than or equal to 20°C, preferably greater than or equal to 50°C, most preferably greater than or equal to 80°C. This temperature is usually less than or equal to 150°C, and preferably less than or equal to 140°C.

After elution, the aqueous solution used to elute metal salts can be sent to a chlorination reactor, a dehydrochlorination unit, a biological treatment unit or an oxidation treatment unit.

In a first variant, after elution with chlorohydrins and water, the salt is removed in a suitable manner as a solid without further workup. The salt is then disposed of in a suitable manner.

In a second variant, the salt is dissolved with an aqueous solution after elution with chlorohydrins and water.

The aqueous solution can come from any step of the process. Preference is given to using fresh water as defined above.

The dissolving step may be performed at a temperature generally greater than or equal to 20°C, preferably greater than or equal to 50°C, most preferably greater than or equal to 80°C. This temperature is usually less than or equal to 150°C, and preferably less than or equal to 140°C.

Aqueous solutions containing dissolved metal salts can be disposed of. Preferably, it can be sent to a dehydrochlorination unit, a biological treatment unit or an oxidation treatment unit.

In a variation of the above, elution of the metal salt with water and dissolution of the metal salt with water may be part of a single unit operation.

The above operation is especially suitable when the metal salt is sodium chloride or potassium chloride or sodium sulfate or potassium sulfate or any mixture thereof, more especially for sodium chloride.

When cleaning is performed in a discontinuous manner, one filter unit is usually sufficient, as the filter system can be regenerated during cleaning shutdowns. When cleaning is performed in a continuous manner, it is preferred to have at least two filter units operating alternately, one in filter mode and the other in regeneration mode.

Filtration operations can be performed batchwise or continuously.

When anhydrous HCl is used as the chlorinating agent, it is preferred to direct the polyhydroxy aliphatic hydrocarbon-containing liquid stream against the flow of the HCl stream. When the process is carried out in several reactors, the HCl is advantageously dried between the two reactors, for example by adsorption with a suitable solid such as molecular sieves, or by reverse osmosis through a suitable membrane.

This particular embodiment of the process according to the invention makes it possible to obtain concentrated chlorohydrins particularly economically, in which the content of chlorohydrins is often greater than or equal to 90% by weight, based on the total weight of chlorohydrins. When the chlorohydrin is dichloropropanol, by this process, 1,3-dichloropropan-2-ol can be obtained as the main isomer with a purity greater than 80%.

In the method according to the invention, the mixture may contain 1,3-dichloropropan-2-ol and The isomers of 2,3-dichloropropan-1 alcohol are usually 0.5 or more, often 3 or more, often 7 or more, especially 20.0 or more.

The invention also relates to a process for the production of chlorohydrins, according to which:

(a) reacting polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof with a chlorinating agent in a reaction medium,

(b) continuously or periodically withdrawing at least a portion of the reaction medium containing water and chlorohydrins,

(c) introducing at least a part of the reaction medium (or fraction) obtained in step (b) into the distillation step,

(d) Controlling the reflux ratio of the distillation step by supplying water to the distillation step.

The reaction medium is as defined above.

The water content of the withdrawn portion (or fraction) in step (b) is preferably greater than or equal to 12% by weight relative to the total weight of the withdrawn portion.

The portion (or fraction) withdrawn in step (b) may also contain hydrogen chloride. Preferably, the portion is withdrawn continuously in its component form. The fraction obtained may be followed by a distillation step followed by a settling (or phase separation) operation.

The reaction medium of step (a) may be supplied with water, especially water vapour. This feeding can be accomplished with external water from a suitable line or alternatively with residual water recovered from other unit reactions or operations.

This feed is usually carried out in such a way as to maintain the water content in the reaction medium as described in the patent application WO 2005/054167 in the name of SOLVAY SA, page 10, line 31 to page 11, line 11 within range.

Continuous or periodic withdrawal can be achieved by introducing the gas phase into the distillation step, in particular by withdrawing the gas phase in equilibrium with the liquid phase and introducing this gas phase into the distillation step. In a particular embodiment of the process according to the invention, steps (a) to (d) are carried out in a reactor topped with a suitable distillation column. Step (a) is carried out in the reactor. This embodiment is particularly suitable when aqueous hydrochloric acid is used as the chlorinating agent. It is most suitable when the chlorinating agent does not contain gaseous hydrogen chloride. In another embodiment of the method according to the invention, it is also possible to arrange the distillation column and the reactor separately, and the bottom liquid of the reactor can be returned to the reaction medium. This embodiment is particularly suitable when hydrogen chloride, such as gaseous or substantially anhydrous hydrogen chloride, is used as the chlorinating agent. The anhydrous hydrogen chloride generally has a water content of less than or equal to 40% by weight, preferably less than or equal to 30% by weight, and most preferably less than or equal to 25% by weight. The water content of anhydrous hydrogen chloride is generally greater than or equal to 1 ppm by weight.

In one aspect, a portion (or fraction) to be introduced into a distillation column separate from the reactor is continuously or periodically, preferably continuously, withdrawn from the liquid reaction mixture and at least water and chlorohydrins are separated. Furthermore, one or more fractions (or fractions) containing organic products such as heavy by-products, in particular catalyst and/or hydrogen chloride, may also be separated in this distillation step and generally recycled to the reaction mixture. By choosing a suitable reflux ratio, it is possible in this respect to separate a fraction which contains at least water and is substantially free of hydrogen chloride.

The reflux ratio can be appropriately adjusted by feeding water, preferably substantially free of hydrogen chloride, into the distillation column. In this embodiment, water is preferably fed to the top of the distillation column. Water may be supplied, for example, by recycling at least a portion of the water separated in the distillation operation to the top of the distillation column. Water can also be supplied by adding fresh water to the top of the distillation column. These two ways of supplying water can be used in combination. Especially good results were obtained with the addition of fresh water.

"Essentially free of hydrogen chloride" is specifically understood to mean that the hydrogen chloride content in the aqueous fraction (or part) is equal to or less than 10% by weight of the total weight of the aqueous fraction. Often the content is equal to or less than 5% by weight, preferably equal to or less than 1% by weight, more preferably equal to or less than 0.3% by weight. If the hydrogen chloride present in the fraction is "substantially free of hydrogen chloride", it is usually present in an amount equal to or greater than 1 mg/kg, often equal to or greater than 10 mg/kg, relative to the total weight of the aqueous fraction.

"Fresh" water is understood as water having a content of other organic or inorganic components other than water of less than or equal to 12% by weight, preferably less than or equal to 10% by weight, most preferably less than Or equal to 1% by weight. In general, "fresh" water is specifically understood as water having a content of other organic or inorganic components other than water, relative to the total weight of water and other components, greater than or equal to 0.001 mg/kg, often greater than or equal to 1 mg/kg, often Greater than or equal to 10mg/kg. Possible sources of fresh water may be, for example, water used for elution of metal salts as described below, water obtained by ion exchange resins, distilled water or water from condensation of water vapor.

Wherein the component that is not water, it refers more specifically to chlorohydrins.

It has been found that the use of the liquid-vapor equilibrium (gas-liquid equilibrium) characteristic of the water-hydrogen chloride-chlorohydrin ternary composition makes it possible to withdraw from the production reaction the reaction product comprising specifically chlorohydrin and water, while leaving most of the catalyst and reactants (including hydrogen chloride) is recycled to the reactor, especially when the chlorohydrin is dichloropropanol.

The invention also relates to a process for the production of chlorohydrins, according to which:

(a) reacting polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof with hydrogen chloride in a reaction mixture,

(b) continuously or periodically withdrawing a portion of the reaction mixture containing at least water, chlorohydrins and hydrogen chloride,

(c) introducing at least a part of the fraction (or fraction) obtained in step (b) into a distillation step,

Wherein the distillate entering the distillation step has a hydrogen chloride concentration/water concentration ratio that is less than the hydrogen chloride/water concentration ratio of the hydrogen chloride/water binary azeotropic composition at the distillation temperature and pressure.

The process is preferably carried out continuously.

In the process according to the invention, preference is given to the operating conditions of the reactor in which polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof are reacted with chlorohydrins, such as reactants (in particular hydrogen chloride and polyhydroxy aliphatic hydrocarbons) aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof), catalyst feed rate, temperature, reactor volume and pressure are adjusted such that the hydrogen chloride concentration of the mixture introduced into the distillation step is within the range of the distillation temperature and pressure lower than the concentration of hydrogen chloride in the binary azeotropic composition of hydrogen chloride/water. An effective way to regulate this concentration is to control the supply of hydrogen chloride to the liquid reaction medium.

The hydrogen chloride content in step (b) can be controlled, for example, by adding water. This addition can be done, for example, by injecting steam into the distillation column boiler used in the distillation step, or by recycling to the distillation step an aqueous phase which can be removed, for example, by decantation (or phase separation) from The distillate is obtained from the top fraction of the distillation column, either by adding fresh water to the top of the distillation column, or by adding a mixture of recycled water and fresh water.

The maximum suitable concentration of hydrogen chloride slightly decreases when the operating pressure is higher, which is related to the liquid-vapor equilibrium (or gas-liquid equilibrium) data (J.Amer.Chem.Soc.52, 633 (1930)), some of their data are reproduced in the following table: Pressure (Torr) temperature(℃) HCl in azeotrope (%wt) 50 48.74 23.42 250 85.21 21.88 370 90.24 21.37 540 99.65 20.92 760 108.58 20.22 1000 116.19 19.73 1220 122.98 19.36

Under such conditions, a water-containing, substantially hydrogen chloride-free fraction as defined above may be recovered from the reaction mixture or from the gas phase above the liquid reaction mixture by distillation, e.g. by distillation of material taken from said gas phase and Preference is given to the fraction comprising water obtained at the top of the distillation column.

For example, at atmospheric pressure (101.3 kPa), water and dichloropropane can be obtained by distillation of the reactor gas phase if the hydrogen chloride content of the gas phase in contact with the reaction medium is less than about 20.22% by weight relative to the total hydrogen chloride and water content Binary azeotropic mixture of alcohols containing 23% by weight of dichloropropanol.

In the process for the production of chlorohydrins according to the invention, the chlorohydrins may comprise an increased content of halogenated ketones, in particular chloroacetone, as described in patent application FR 05.05120 filed on May 20, 2005 in the name of SOLVAY SA , and the contents of the above patent application are hereby incorporated by reference. In the process for producing chlorohydrins according to the present invention, the haloketone content of chlorohydrins can be reduced by azeotropic distillation in the presence of water or by dehydrochlorination of the chlorohydrins, as described in May 2005 Described in patent application FR 05.05120 of SOLVAY SA filed on the 20th. Particular mention is made of a process for the production of epoxides in which a haloketone is formed as a by-product and which comprises at least one treatment for removing at least a portion of the haloketone formed. More particularly reference is made to a process for the production of epoxides by dehydrochlorination of chlorohydrins, wherein at least a portion of the chlorohydrins is produced by chlorination of polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons or mixtures thereof , produced by dehydrochlorination and treatment of a water-haloketone mixture by azeotropic distillation for removal of at least a portion of the haloketone formed, and a process (or method) for the production of epichlorohydrin, wherein the halogenated The ketone is chloroacetone.

In the process according to the invention for the production of chlorohydrins, a surprisingly high selectivity to 1,3-dichloropropan-2-ol is obtained when the chlorohydrin is dichloropropanol, 1,3- Dichloropropan-2-ol is especially suitable as starting product for dehydrochlorination for the production of epichlorohydrin.

In the process according to the invention, chlorohydrins can be subjected to a dehydrochlorination reaction to produce epoxides, as described in patent applications WO 2005/054167 and FR 05.05120 in the name of SOLVAY SA.

In the method according to the present invention, chlorohydrins can be dehydrochlorinated, as in the patent application entitled "Process formanufacturing an epoxy from a multi-hydroxylated aliphatichydrocarbon and a chlorinating agent" submitted in the name of SOLVAY SA on the same date as this application described in , the contents of which are incorporated herein by reference.

Particular mention is made of a process for the production of epoxides in which a reaction mixture is obtained from the reaction of polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or mixtures thereof with a chlorinating agent, the reaction mixture containing at least 10 g of chlorinated Alcohol/kg reaction mixture, which undergoes additional chemical reactions without intermediate workup.

Mention is made in particular of a process for the production of epoxides, comprising the steps of: (a) reacting polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons, or mixtures thereof with chlorinating agents and organic acids, whereby in the presence of Polyhydroxyaliphatic hydrocarbons, esters of polyhydroxyaliphatic hydrocarbons, water, chlorohydrins and esters of chlorohydrins formed in a reaction mixture of the chlorinating agent and an organic acid, the reaction mixture containing at least 10 g of chlorohydrins per kg of the reaction mixture alcohol; (b) at least a part of the reaction mixture obtained in step (a) (this part of the mixture has the same composition as the reaction mixture obtained in step (a)) is carried out once or in a step after step (a) multiple treatments; and (c) adding a basic compound in at least one step after step (a) to at least partially react with chlorohydrins, esters of chlorohydrins, chlorinating agents and organic acids to form a cyclic oxides and salts.

The process for the production of chlorohydrins according to the invention can be integrated in the overall design as described in the patent application entitled "Process for manufacturing anepoxide from a chlorohydrin" filed on the same date as the present application in the name of SOLVAY SA, and The contents of the above patent applications are hereby incorporated by reference.

Particular mention is made of a process for the production of epoxides comprising at least one step of purifying the epoxides produced at least in part by dehydrochlorination of chlorohydrins at least in part It is produced by chlorination of polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or their mixtures.

When the chlorohydrin is dichlorohydrin, the process of the invention can be followed by the dehydrochlorination of dichlorohydrin to produce epichlorohydrin, and when the epoxide is epichlorohydrin, the epichlorohydrin can generally be Used in the production of epoxy resins.

Figure 1 shows a flow diagram of a particularly preferred plant that can be used to practice the production of chlorohydrins according to the invention. It supplies polyhydroxy aliphatic hydrocarbons, esters of polyhydroxy aliphatic hydrocarbons or their mixtures through line (1) to reactor (4) in a continuous or intermittent manner, supplies catalyst through line (2), and the feed of chlorinating agent is Continuously or intermittently via line (3), distillation column (6) is supplied with steam generated by reactor (4) via line (5), a stream of fluid is withdrawn from column (6) via line (7) and Sent into condenser (8), a stream of fluid from condenser (8) is sent in the decanter (or phase separator) (10) through pipeline (9), in the decanter water phase and organic The phases are separated. A part of the separated aqueous phase is optionally recycled to the top of the column via line (11) for maintaining reflux (ratio). Fresh water can be added to the top of the column via line (12) for maintaining reflux (ratio). The resulting chlorohydrins are partitioned between the organic phase withdrawn via line (14) and the aqueous phase withdrawn via line (13). The residue from column (6) can be recycled to the reactor via line (15). Heavy by-products can optionally be removed from the reactor by means of a purge (16) located in the reactor bottom liquid. A liquid stream is taken from the purge (16) and fed through line (17) to the evaporator (18), where it is subjected to partial evaporation, e.g. by heating or by purging with nitrogen or steam, from the liquid The gaseous phase of stream (17) comprising most of the chlorinating agent is recycled to column (6) via line (19) or to reactor (4) via line (20), and the distillation or stripping column (22) is passed Line (21) supplies the liquid phase from the evaporator (18), the main fraction of chlorohydrins is taken from the top of the column (22) via line (23) and the residue of the column is supplied to the filtration unit (25) via line (24). ), where the solid and liquid phases are separated and the liquid phase is recycled to the reactor (4) via line (26). The solid can be withdrawn from the filtration unit (25) via line (27) as a solid or as a solution. Solvent can be fed to filtration unit (25) via lines (28) and (29) for washing and/or solid dissolution and withdrawn from line (27). Optionally, a liquid stream is taken from the wash (16) and fed into the filtration unit (25) via line (30). The stripping column (18) and distillation column (22) are then bypassed.

The results obtained according to this last scheme (with stripping column (18) and (distillation) column (22) bypassed) are detailed in the examples.

When the polyhydroxy aliphatic hydrocarbon is ethylene glycol, propylene glycol and glycerin, the chlorohydrin is chlorohydrin, chloropropanol, chloropropanediol and dichloropropanol, and the epoxide is ethylene oxide, propylene oxide, glycidol and When epichlorohydrin and chlorinating agent are anhydrous hydrogen chloride or hydrogen chloride aqueous solution, the method described above is very suitable. This method is especially convenient when the polyhydric aliphatic hydrocarbon is glycerol, the chlorohydrin is dichlorohydrin and the epoxide is epichlorohydrin.

When the polyhydroxy aliphatic hydrocarbon is glycerol, this variant of the process allows to remove almost all the water from the reaction, from the starting material and/or possibly supplied at the bottom of the reactor or column at the top by azeotropy , resulting in a mixture of dichloropropanols of extremely high purity, exceeding 99.5% by weight for the sum of the two isomers (which has a selectivity higher than 99% by weight with respect to hydrocarbon chains and hydrogen chloride), and removed when in Metal salts that can accumulate in the reactor when crude glycerin is used in the reactor.

The following examples are given to illustrate the invention but not to limit it.

Example 1

Numbers in parentheses refer to Figure 1. The additional equipment with stripping column (18) and (distillation) column (22) in the scheme of Figure 1 is not used in this example.

Reactor (4) has been continuously supplied with crude glycerin and 33% by weight aqueous hydrochloric acid at a relative flow mass ratio of 2.06. The crude glycerol is a by-product of biodiesel production and contains 85% glycerol, 6% NaCl and 0.5% organic impurities (fatty acids and derivatives). The residence time is 16 h, the concentration of adipic acid in the reaction medium is 2.5 mol acid functions/kg. The reactor was operated at atmospheric pressure and 115°C. The reaction mixture has been stripped with nitrogen and the resulting vapor phase has been worked up in a distillation column (6) via line (5) (Figure 1). The gaseous phase removed from the column (6) has been condensed (8) at 25°C and decanted (or phase separated) in a decanter (10). The reflux ratio is adjusted to remove all the dichloropropanol produced at the top of the column by recycling a suitable amount of the aqueous phase from the decanter. An aqueous phase ( 13 ) containing 15.0% dichloropropanol and an organic phase ( 14 ) containing 88% dichloropropanol are recovered at the outlet of the decanter. Measurements of organic impurities in these two phases showed no difference from using pure glycerol in this method.

The slurry from the reactor has been pumped onto a 115 micron PTFE membrane filter in the filter column (25). The salt cake in the filter has been washed with dichloropropanol saturated with water at 20°C. After removing the liquid phase and draining the solids, the salt was dissolved in water and the brine phase was discarded. The duration of washing and salt dissolution is about 2 hours. The slurry from the reactor was then subjected to a new filtration cycle. The dichloropropanol wash has been recycled back to the reactor by continuous feeding. Analysis of the aqueous phase with salts indicated a dichloropropanol:NaCl mass ratio of 1.44 and a small amount of catalyst (less than 10 g/kg). The amount of dichloropropanol in the brine represented 1.6% of the total dichlorohydrin product.

The overall yield as dichloropropanol (expressed) was 93%.

Claims (26)

1. the method that is used to produce chloro-hydrin(e) of ester or the reaction between their mixture and the chlorizating agent by polyhydroxylated aliphatic hydrocarbons, polyhydroxylated aliphatic hydrocarbons, contain at least a solid or dissolved metal-salt according to the described polyhydroxylated aliphatic hydrocarbons of described method use, the ester or their mixture of polyhydroxylated aliphatic hydrocarbons, described method comprises that a lock out operation is to remove to the described metal-salt of small part.

2. method according to claim 1, the ester of use therein described polyhydroxylated aliphatic hydrocarbons, polyhydroxylated aliphatic hydrocarbons or their mixture to small part is obtained by renewable raw materials.

3. method according to claim 1 and 2, wherein said metal-salt is selected from sodium-chlor, Repone K, sodium sulfate and vitriolate of tartar.

4. according to each described method in the claim 1 to 3, the ester of wherein said polyhydroxylated aliphatic hydrocarbons, polyhydroxylated aliphatic hydrocarbons or their mixture contain the metal-salt of 0.5 to 15 weight %.

5. according to each described method in the claim 1 to 4, wherein said chlorizating agent is the combination or the hydrochloride aqueous solution of gas chlorination hydrogen and hydrochloride aqueous solution.

6. according to each described method in the claim 1 to 5, wherein said reaction is carried out in the presence of catalyzer.

7. method according to claim 6, wherein said catalyzer are carboxylic acid or carboxylic acid derivative.

8. method according to claim 7, wherein said carboxylic acid has the atmospheric boiling point that is greater than or equal to 200 ℃, preferably the derivative of hexanodioic acid or hexanodioic acid.

9. according to each described method in the claim 1 to 8, wherein said lock out operation is selected from liquid/solid, liquid/liquid, liquid/gas and solid/gas to be separated.

10. method according to claim 9, Gu wherein said liquid/lock out operation is selected from decant, centrifugal, filtration, absorption and spent ion exchange resin and handles, described liquid/liquid lock out operation is selected from decant and centrifugal, and described liquid/gas lock out operation is selected from stripping, evaporation and distillation.

11. method according to claim 10, Gu wherein said liquid/lock out operation is to filter, and wherein said metal-salt is removed as solid.

12. according to each described method in the claim 1 to 11, wherein said reaction is carried out in reaction mixture, and described lock out operation is to carry out at least a portion of described reaction mixture.

13. method according to claim 12 is wherein handled at least a composition that is not described metal-salt to remove before described lock out operation to the part of described reaction mixture.

14. method according to claim 13, wherein said processing are stripping or distillation procedure.

15. according to each described method in the claim 1 to 14, described method is carried out continuously.

16. be used to produce the method for chloro-hydrin(e), the ester of the polyhydroxylated aliphatic hydrocarbons that contains 10 weight % organic impuritys at the most, polyhydroxylated aliphatic hydrocarbons or their mixture and chlorizating agent reacted according to described method.

17. be used to produce the method for chloro-hydrin(e), according to described method

(a) ester of polyhydroxylated aliphatic hydrocarbons, polyhydroxylated aliphatic hydrocarbons or their mixture and chlorizating agent are reacted in reaction medium;

(b) from described reaction medium, take out the part that contains water and described chloro-hydrin(e) at least continuously or off and on;

(c) will be incorporated in the distilation steps at least partially in the described part that obtains in the step (b); And

(d) by supplying with the splitting ratio that water is controlled described distilation steps to described distilation steps.

18. method according to claim 17, wherein described in step (b) taken out part and has water-content more than or equal to 21 weight % with respect to described gross weight of taking out part.

19. be used to produce the method for chloro-hydrin(e), according to described method

(a) ester of polyhydroxylated aliphatic hydrocarbons, polyhydroxylated aliphatic hydrocarbons or their mixture and hydrogenchloride are reacted in reaction medium;

(b) from described reaction medium, take out the part that contains water, described chloro-hydrin(e) and hydrogenchloride at least continuously or off and on;

(c) will be incorporated in the distilation steps at least partially in the described part that obtains in the step (b);

Wherein be incorporated into the ratio that the described hydrogen chloride content of the described part in the described distilation steps and the ratio between the described water-content are lower than binary azeotropic under described distillation temperature and the pressure hydrogenchloride/water in forming.

20. according to each described method in the claim 1 to 19, wherein said polyhydroxylated aliphatic hydrocarbons is selected from ethylene glycol, propylene glycol, propylene glycol of chlorine, glycerine and composition thereof.

21. according to each described method in the claim 1 to 20, wherein said chloro-hydrin(e) is chloroethanol, propylene chlorohydrin, propylene glycol of chlorine, dichlorohydrine and composition thereof.

22. according to claim 20 or 21 described methods, wherein said polyhydroxylated aliphatic hydrocarbons is a glycerine, and described chloro-hydrin(e) is a dichlorohydrine.

23. method according to claim 22 is produced Epicholorohydrin by the dichlorohydrine dehydrochlorination subsequently.

24. method according to claim 23, wherein said Epicholorohydrin is used to produce Resins, epoxy.

25. method according to claim 22, a use therein described glycerine part is to obtain in the process of production biofuel, or in the fatty or oily conversion process of plant or animal-origin, obtain, described conversion is selected from saponification, transesterification or hydrolysis reaction.

26. method according to claim 25, wherein said oil or fat are selected from Semen Maydis oil, sunflower seed oil, outmoded or new rapeseed oil, babassu oil, Oleum Cocois, wild cabbage tree oil, plam oil, Viscotrol C and Oleum Gossypii semen, peanut oil, soybean oil, oleum lini and Crambe oil, fat, " linseed oil stand oil ", part poly or the oligomeric sunflower seed oil and the flowering plant oil of the oil that is obtained by Sunflower Receptacle crop that obtains by genetic modification or hybridization or vegetable seed crop, the old oil of frying, fish oil, butter, lard, dismemberent.