Abstract: The present invention relates to a method of preparing an alkyl (meth)acrylate, and more specifically to a method of preparing an alkyl (meth)acrylate which comprises the steps of: carrying out an esterification reaction with reactants comprising an alkanol and (meth)acrylic acid in the presence of an organic acid catalyst with a conversion rate of about 70% or more; supplying reaction products of the esterification reaction to a distillation tower equipped with a reboiler at the lower end to purify them; recovering a upper discharge comprising an alkyl (meth)acrylate and water at the upper part of the distillation tower and recovering a lower discharge comprising high boiling materials and water at the lower part of the distillation tower; separating the lower discharge of the distillation tower into a water layer and an organic layer; and recirculating the water layer separated from the lower discharge so as to be used in the esterification reaction, wherein each of the steps occurs continuously and the low

Abstract: The present invention relates to a method and apparatus for continuous recovery of (meth)acrylic acid, and more specifically to a method of continuous recovery of (meth)acrylic acid, including: conducting gas phase oxidation of at least one compound selected from the group consisting of propane, propylene, butane, i-butylene, t-butylene, and (meth)acrolein in the presence of a catalyst to obtain a mixed gas containing (meth)acrylic acid; quenching the (meth)acrylic acid-containing mixed gas to remove high boiling point by-products in the (meth)acrylic acid-containing mixed gas; contacting the high boiling point by-product-free (meth)acrylic acid-containing mixed gas with water or an aqueous solution to obtain an aqueous solution containing (meth)acrylic acid; and purifying the aqueous solution containing (meth)acrylic acid to obtain (meth)acrylic acid.

Abstract: The present invention relates to a method and apparatus for continuous recovery of (meth)acrylic acid, and more specifically to a method of continuous recovery of (meth)acrylic acid, including: conducting gas phase oxidation of at least one compound selected from the group consisting of propane, propylene, butane, i-butylene, t-butylene, and (meth)acrolein in the presence of a catalyst to obtain a mixed gas containing (meth)acrylic acid; quenching the (meth)acrylic acid-containing mixed gas to remove high boiling point by-products in the (meth)acrylic acid-containing mixed gas; contacting the high boiling point by-product-free (meth)acrylic acid-containing mixed gas with water or an aqueous solution to obtain an aqueous solution containing (meth)acrylic acid; and purifying the aqueous solution containing (meth)acrylic acid to obtain (meth)acrylic acid.

Abstract: The present invention relates to a method of preparing an alkyl (meth)acrylate, and more specifically to a method of preparing an alkyl (meth)acrylate which comprises the steps of: carrying out an esterification reaction with reactants comprising an alkanol and (meth)acrylic acid in the presence of an organic acid catalyst with a conversion rate of about 70% or more; supplying reaction products of the esterification reaction to a distillation tower equipped with a reboiler at the lower end to purify them; recovering a upper discharge comprising an alkyl (meth)acrylate and water at the upper part of the distillation tower and recovering a lower discharge comprising high boiling materials and water at the lower part of the distillation tower; separating the lower discharge of the distillation tower into a water layer and an organic layer; and recirculating the water layer separated from the lower discharge so as to be used in the esterification reaction, wherein each of the steps occurs continuously and the low

Abstract: Disclosed is an apparatus for recovering an acrylic acid from a mixture containing acrylic acid, acrylic acid dimer and impurities with high boiling point, including: an acrylic acid recovering device that comprises an acrylic acid distillation unit being present within an acrylic acid dimer pyrolysis tank, and is operated under reduced pressure; a separation column for removing impurities with high boiling point from the mixture which is introduced into the acrylic acid recovering device; and a line for introducing the mixture into the acrylic acid recovering device.

Abstract: The present invention provides a (meth)acrylic acid collecting method for collecting a (meth)acrylic acid from a mixed gas that includes an organic byproduct, a steam, and a (meth)acrylic acid that are generated in a production reaction of the (meth)acrylic acid, which includes the steps of a) contacting the mixed gas that includes the organic byproduct, the steam, and the (meth)acrylic acid with a (meth)acrylic acid absorption solvent to obtain a gas that includes the organic byproduct and the steam and the (meth)acrylic acid containing solution while the gas and the (meth)acrylic acid containing solution are separated from each other; b) contacting the gas that includes the organic byproduct and the steam that are obtained in the step a with the organic byproduct absorption solvent to obtain the gas that includes the steam and the organic byproduct containing solution while the gas and the organic byproduct containing solution are separated from each other; c) supplying the gas that includes the steam that

Abstract: Disclosed is a shell-and-tube heat exchanger type reactor that can be used for a process of producing unsaturated acids from olefins via fixed-bed catalytic partial oxidation, which comprises at least one reaction tube, each including at least one first-step catalyst layer, in which olefins are oxidized by a first-step catalyst to mainly produce unsaturated aldehydes, and at least two second-step catalyst layers, in which the unsaturated aldehydes are oxidized by a second-step catalyst to produce unsaturated acids, wherein a first catalyst layer of the second-step catalyst layers, disposed right adjacent to the first-step catalyst layer, has an activity corresponding to 5˜30% of the activity of the catalyst layer having a highest activity among the second-step catalyst layers. A method of producing unsaturated acids from olefins by using the reactor is also disclosed.

Abstract: The present invention provides a method of recovering a (meth)acrylic acid ester, which comprises the steps of: (a) carrying out an esterification reaction between an alcohol and (meth)acrylic acid in the presence of a catalyst to obtain a (meth)acrylic acid ester, wherein a byproduct is generated together with the (meth)acrylic acid ester; and (b) subjecting the byproduct generated in step (a) to a reaction with a catalyst and water in a reactor, wherein the water is fed into the reactor in order that water content exceeds 0 wt % but is 10 wt % or less in the reactor based on the total weight of reactants comprising the byproduct, the catalyst and the water, and thereby separating the (meth)acrylic acid, the alcohol and the (meth)acrylic acid ester contained in the byproduct from the byproduct to obtain the (meth)acrylic acid, the alcohol and the (meth)acrylic acid ester as a recovered product.

Abstract: The present invention provides a method for preparing unsaturated aldehydes and/or unsaturated fatty acids from olefins using a fixed-bed catalytic partial oxidation reactor, in particular, a start-up method upon packing with catalysts and initiating the reaction, and a process for producing unsaturated aldehydes and/or unsaturated fatty acids with high yield.

Abstract: The present invention provides a method for preparing (meth)acrylate by esterification reaction of reactants containing (meth)acrylic acid and alcohol in the presence of a catalyst, the preparation method for (meth)acrylate is characterized in that a hydrazine compound or derivative thereof is put into an esterification reactor; and (meth)acrylate prepared by the same. The present invention effectively prevents impurities generated by aldehyde that is contained in the raw material (meth)acrylic acid from remaining in a production apparatus and the catalyst, so that the process for producing (meth)acrylate proceeds smoothly.

Abstract: Disclosed is a shell-and-tube heat exchanger type reactor that can be used for a process of producing unsaturated acids from olefins via fixed-bed catalytic partial oxidation, which comprises at least one reaction tube, each including at least one first-step catalyst layer, in which olefins are oxidized by a first-step catalyst to mainly produce unsaturated aldehydes, and at least two second-step catalyst layers, in which the unsaturated aldehydes are oxidized by a second-step catalyst to produce unsaturated acids, wherein a first catalyst layer of the second-step catalyst layers, disposed right adjacent to the first-step catalyst layer, has an activity corresponding to 5˜30% of the activity of the catalyst layer having a highest activity among the second-step catalyst layers. A method of producing unsaturated acids from olefins by using the reactor is also disclosed.

Abstract: Disclosed is a shell-and-tube heat exchanger type reactor that can be used for a process of producing unsaturated acids from olefins via fixed-bed catalytic partial oxidation, which comprises at least one reaction tube, each including at least one first-step catalyst layer, in which olefins are oxidized by a first-step catalyst to mainly produce unsaturated aldehydes, and at least two second-step catalyst layers, in which the unsaturated aldehydes are oxidized by a second-step catalyst to produce unsaturated acids, wherein a first catalyst layer of the second-step catalyst layers, disposed right adjacent to the first-step catalyst layer, has an activity corresponding to 5˜30% of the activity of the catalyst layer having a highest activity among the second-step catalyst layers. A method of producing unsaturated acids from olefins by using the reactor is also disclosed.

Abstract: The present invention provides a (meth)acrylic acid collecting method for collecting a (meth)acrylic acid from a mixed gas that includes an organic byproduct, a steam, and a (meth)acrylic acid that are generated in a production reaction of the (meth)acrylic acid, which includes the steps of a) contacting the mixed gas that includes the organic byproduct, the steam, and the (meth)acrylic acid with a (meth)acrylic acid absorption solvent to obtain a gas that includes the organic byproduct and the steam and the (meth)acrylic acid containing solution while the gas and the (meth)acrylic acid containing solution are separated from each other; b) contacting the gas that includes the organic byproduct and the steam that are obtained in the step a with the organic byproduct absorption solvent to obtain the gas that includes the steam and the organic byproduct containing solution while the gas and the organic byproduct containing solution are separated from each other; c) supplying the gas that includes the steam that

Abstract: The present invention provides a method for preparing unsaturated aldehydes and/or unsaturated fatty acids from olefins using a fixed-bed catalytic partial oxidation reactor, in particular, a start-up method upon packing with catalysts and initiating the reaction, and a process for producing unsaturated aldehydes and/or unsaturated fatty acids with high yield.

Abstract: A shell-and-tube heat exchanger-type reactor including one or more catalytic tubes, each including a first-step reaction zone and a second-step reaction zone, wherein at least one of the first-step reaction zone and the second-step reaction zone is divided into two or more shell spaces by a partition; each of the divided shell spaces is independently heat-controlled; and a heat transfer medium having a temperature from the lowest active temperature of a catalyst layer in a reaction tube corresponding to the first shell space of the first-step reaction zone or the first shell space of the second-step reaction zone to the lowest active temperature of the catalyst layer plus 20° C.; and the first shell space of the first-step reaction zone or the first shell space of the second-step reaction zone is controlled so as to provide a reactant conversion contribution per length of 1.2˜2.5.

Abstract: Disclosed is a simplified apparatus for recovering acrylic acid from a mixture containing acrylic acid, acrylic acid dimer and impurities with high boiling point, in a stable and efficient manner. An apparatus for recovering an acrylic acid from a mixture containing acrylic acid, acrylic acid dimer and impurities with high boiling point, which comprises: an acrylic acid recovering device that comprises an acrylic acid distillation unit being present within an acrylic acid dimer pyrolysis tank, and is operated under reduced pressure; and a line for introducing the mixture into the acrylic acid recovering device, wherein decomposition of the acrylic acid dimer is carried out under reduced pressure at a lower part of the acrylic acid recovering device, while the acrylic acid is recovered by distillation under reduced pressure from a top of the acrylic acid recovering device.

Abstract: Disclosed is a method for producing (meth)acrylic acid comprising a process of recovering (meth)acrylic acid as aqueous (meth)acrylic acid solution from a (meth)acrylic acid-containing gas mixture produced by the catalytic gas phase oxidation of at least one reactant selected from the group consisting of propane, propylene, isobutylene and (meth)acrolein, wherein the recovering process comprises the steps of: (1) feeding the (meth)acrylic acid-containing gas mixture into a quenching tower and condensing it in the quenching tower so as to recover an aqueous (meth)acrylic acid solution from the bottom of the quenching tower, in which some of the recovered aqueous (meth)acrylic acid solution is recycled to the upper portion of the quenching tower so as to condense the (meth)acrylic acid-containing gas mixture; (2) passing the uncondensed part of the (meth)acrylic acid-containing gas mixture from the top of the quenching tower to a distillation tower; and (3) heating the bottom of the distillation tower to separa

Abstract: Disclosed is a simplified method for recovering acrylic acid from a mixture containing acrylic acid, acrylic acid dimer and impurities with high boiling point, in a stable and efficient manner. The method comprises the steps of: introducing the mixture into an acrylic acid recovering device comprising an acrylic distillation unit integrated with an acrylic acid dimer pyrolysis tank; carrying out decomposition of acrylic acid dimmer under reduced pressure and recovering acrylic acid. The method optionally further comprises a step of recycling a portion of the solution obtained from the bottom of the acrylic acid recovering device to the acrylic acid recovering device.

Abstract: Disclosed is a process for producing unsaturated aldehydes and/or unsaturated acids from olefins or alkanes in a fixed bed shell-and-tube heat exchanger-type reactor by catalytic vapor phase oxidation. A heat exchanger-type reactor for use in such a process is also disclosed. The process utilizes at least one first-step reaction zone and a second-step reaction zone that is divided into two or more shell spaces by at least one partition. The process may be applied to a single-step process for producing unsaturated acids from alkanes or alkenes.

Abstract: Disclosed is a temperature measuring device. The temperature measuring device includes: a thermo-well tube; and a cable or wire type temperature measuring means which is installed in a thermo-well tube, wherein temperature measuring means has temperature detecting sensors disposed at an intermediate portion thereof, and the temperature detecting sensors can be moved axially in the thermo-well tube by applying tension to both ends of the cable or wire type temperature measuring means. The present invention also provides a reaction tube in which the temperature measuring device is disposed axially, and a reactor including at least one temperature measuring device or reaction tube as described above.