The present disclosure addresses the problem of providing a method for purifying an acrylic acid ester compound. This problem can be solved by a method for purifying a compound represented by formula (1)

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(wherein R.sup.1 and R.sup.2 are the same as or different and each represent an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituent groups, a halogen atom, or a hydrogen atom, R.sup.3 is an alkyl group, a fluoroalkyl group, or an aryl group optionally having one or more substituent groups, and X is a fluoroalkyl group or a halogen atom), the method including step A of distilling composition A containing (a) the compound represented by formula (1), (b) an alcohol, and (c) a salt so as to obtain a concentrate containing the compound represented by formula (1).

A process for obtaining product streams enriched with polyol esters from the secondary streams from polyol ester preparation, comprising a) the reaction of polyols of the general formula (II)
H—(—O—[—CR.sup.1R.sup.2—].sub.m—).sub.o—OH  (II) in which R.sup.1 and R.sup.2 are each independently hydrogen, an alkyl radical having 1 to 5 carbon atoms or a hydroxyalkyl radical having 1 to 5 carbon atoms, m is an integer from 1 to 10, o is an integer from 2 to 15, with linear or branched aliphatic monocarboxylic acids having 3 to 20 carbon atom, with removal of the water formed; b) the removal of unconverted starting compounds from the crude ester formed; c) the treatment of the crude ester obtained in step b) with steam to form a volatile secondary stream; and d) the removal of the volatile secondary stream obtained in step c), characterized in that the volatile secondary stream obtained in step d) is separated into an aqueous phase and an organic phase and the organic phase removed is subjected to a further treatment with steam and a product stream enriched with polyol esters is obtained as residue.

A process for obtaining product streams enriched with polyol esters from the secondary streams from polyol ester preparation, comprising a) the reaction of polyols of the general formula (II)
H—(—O—[—CR.sup.1R.sup.2—].sub.m—).sub.o—OH  (II) in which R.sup.1 and R.sup.2 are each independently hydrogen, an alkyl radical having 1 to 5 carbon atoms or a hydroxyalkyl radical having 1 to 5 carbon atoms, m is an integer from 1 to 10, o is an integer from 2 to 15, with linear or branched aliphatic monocarboxylic acids having 3 to 20 carbon atom, with removal of the water formed; b) the removal of unconverted starting compounds from the crude ester formed; c) the treatment of the crude ester obtained in step b) with steam to form a volatile secondary stream; and d) the removal of the volatile secondary stream obtained in step c), characterized in that the volatile secondary stream obtained in step d) is separated into an aqueous phase and an organic phase and the organic phase removed is subjected to a further treatment with steam and a product stream enriched with polyol esters is obtained as residue.

A process for obtaining product streams enriched with polyol esters from the secondary streams from polyol ester preparation, comprising a) the reaction of polyols of the general formula (II)
H—(—O—[—CR.sup.1R.sup.2—].sub.m—).sub.o—OH  (II) in which R.sup.1 and R.sup.2 are each independently hydrogen, an alkyl radical having 1 to 5 carbon atoms or a hydroxyalkyl radical having 1 to 5 carbon atoms, m is an integer from 1 to 10, o is an integer from 2 to 15, with linear or branched aliphatic monocarboxylic acids having 3 to 20 carbon atom, with removal of the water formed; b) the removal of unconverted starting compounds from the crude ester formed; c) the treatment of the crude ester obtained in step b) with steam to form a volatile secondary stream; and d) the removal of the volatile secondary stream obtained in step c), characterized in that the volatile secondary stream obtained in step d) is separated into an aqueous phase and an organic phase and the organic phase removed is subjected to a further treatment with steam and a product stream enriched with polyol esters is obtained as residue.

In a process for purifying fatty acid alkyl esters, particularly methyl and ethyl esters, by means of vacuum distillation in a distillation column, water or steam is introduced into the distillation column and, during distillation, brought into contact with the fatty acid alkyl esters in the gas phase. This results in a significant reduction in the sulphur content and in the acid number of the fatty acid alkyl ester.

In a process for purifying fatty acid alkyl esters, particularly methyl and ethyl esters, by means of vacuum distillation in a distillation column, water or steam is introduced into the distillation column and, during distillation, brought into contact with the fatty acid alkyl esters in the gas phase. This results in a significant reduction in the sulphur content and in the acid number of the fatty acid alkyl ester.

A highly unsaturated fatty acid or a highly unsaturated fatty acid ethyl ester that has been produced using as a feedstock oil a fat or oil that contains highly unsaturated fatty acids as constituent fatty acids and which has been reduced in the contents of environmental pollutants, wherein among the dioxins contained, polychlorinated dibenzoparadioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are contained in amounts of less than 0.05 pg-TEQ/g and coplanar PCBs (Co-PCBs) in amounts of less than 0.03 pg-TEQ/g. Also disclosed is a method for producing the highly unsaturated fatty acid or highly unsaturated fatty acid ethyl ester by the steps of removing free fatty acids and environmental pollutants by thin-film distillation from a feedstock oil, ethyl esterifying the resulting fat or oil, and refining the same by rectification and column chromatography.

A highly unsaturated fatty acid or a highly unsaturated fatty acid ethyl ester that has been produced using as a feedstock oil a fat or oil that contains highly unsaturated fatty acids as constituent fatty acids and which has been reduced in the contents of environmental pollutants, wherein among the dioxins contained, polychlorinated dibenzoparadioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are contained in amounts of less than 0.05 pg-TEQ/g and coplanar PCBs (Co-PCBs) in amounts of less than 0.03 pg-TEQ/g. Also disclosed is a method for producing the highly unsaturated fatty acid or highly unsaturated fatty acid ethyl ester by the steps of removing free fatty acids and environmental pollutants by thin-film distillation from a feedstock oil, ethyl esterifying the resulting fat or oil, and refining the same by rectification and column chromatography.

A highly unsaturated fatty acid or a highly unsaturated fatty acid ethyl ester that has been produced using as a feedstock oil a fat or oil that contains highly unsaturated fatty acids as constituent fatty acids and which has been reduced in the contents of environmental pollutants, wherein among the dioxins contained, polychlorinated dibenzoparadioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are contained in amounts of less than 0.05 pg-TEQ/g and coplanar PCBs (Co-PCBs) in amounts of less than 0.03 pg-TEQ/g. Also disclosed is a method for producing the highly unsaturated fatty acid or highly unsaturated fatty acid ethyl ester by the steps of removing free fatty acids and environmental pollutants by thin-film distillation from a feedstock oil, ethyl esterifying the resulting fat or oil, and refining the same by rectification and column chromatography.

In methods for preparing an alkyl carboxylic acid ester according to an embodiment, a first reaction product is produced by reaction of a carboxylic acid stream and a first alcohol stream in a preliminary reactor. A second reaction product is produced by at least partially removing alcohol and water from the first reaction product. The second reaction product is esterified by reaction with a second alcohol stream in a main reactor. An alkyl carboxylic acid ester is recovered from the main reactor.