Abstract: The present invention relates to a method of producing ethylene by separately collecting ethane and ethylene which are by-products of a propylene preparation process using propane dehydrogenation reaction and also combining an existing propylene preparation process with a process of converting ethane to ethylene. According to the present invention, valuable ethylene may be produced by converting most of ethane and ethylene, i.e., by-products of a propane dehydrogenation process, into ethylene without using the ethane as fuel, thereby improving process economic efficiency. Furthermore, a product line in the process of propane dehydrogenation reaction may be changed from a propylene product alone into two products, i.e., propylene and ethylene, and thus the operating conditions of a propylene dehydrogenation reactor and the operating conditions of a de-ethanizer may be adjusted according to the market situation, thereby increasing the production proportion of a favorable product line.

Abstract: The present invention relates to a method of producing ethylene by separately collecting ethane and ethylene which are by-products of a propylene preparation process using propane dehydrogenation reaction and also combining an existing propylene preparation process with a process of converting ethane to ethylene. According to the present invention, valuable ethylene may be produced by converting most of ethane and ethylene, i.e., by-products of a propane dehydrogenation process, into ethylene without using the ethane as fuel, thereby improving process economic efficiency. Furthermore, a product line in the process of propane dehydrogenation reaction may be changed from a propylene product alone into two products, i.e., propylene and ethylene, and thus the operating conditions of a propylene dehydrogenation reactor and the operating conditions of a de-ethanizer may be adjusted according to the market situation, thereby increasing the production proportion of a favorable product line.

Abstract: This invention relates to a dehydrogenation catalyst having a macropore size and a high active density of platinum, suitable for use in dehydrogenation of a hydrocarbon gas. This dehydrogenation catalyst having a macropore size and a high active density of platinum is highly active, has high active density per unit catalytic surface area, facilitates material transfer of reactants and products, delays deactivation due to coke formation, keeps the initial activity constant after being regenerated thanks to the disposal of coke, has high strength and so is resistant to external impact, and undergoes neither structural changes due to heat nor changes in the properties of active materials.

Abstract: The present invention relates to a method for separating and refining high purity 2,6-naphthalene dicarboxylic acid having an excellent color and purity of 99.9% or more by using crude 2,6-naphthalene dicarboxylic acid. And more particularly, the present invention relates to a method for separating and refining 2,6-naphthalene dicarboxylic acid, in which adjustment of pressure and temperature during multiple-step crystallization process enables controlling nucleation and the crystal growth rate, thereby allowing a particle size distribution and form to be controlled.

Abstract: This invention relates to a dehydrogenation catalyst having a macropore size and a high active density of platinum, suitable for use in dehydrogenation of a hydrocarbon gas. This dehydrogenation catalyst having a macropore size and a high active density of platinum is highly active, has high active density per unit catalytic surface area, facilitates material transfer of reactants and products, delays deactivation due to coke formation, keeps the initial activity constant after being regenerated thanks to the disposal of coke, has high strength and so is resistant to external impact, and undergoes neither structural changes due to heat nor changes in the properties of active materials.

Abstract: The present invention relates to a method for preparing 1,5-dimethyltetralin using a dealuminated zeolite beta catalyst. The preparation method of 1,5-dimethyltetralin according to the present invention has the effects of not only showing high conversion and high selectivity of 1,5-dimethyltetralin but also of suppressing deactivation of a zeolite beta catalyst so as to enhance the catalyst life, by using the dealuminated zeolite beta catalyst.

Abstract: The present invention relates to a method for separating and refining high purity 2,6-naphthalene dicarboxylic acid having an excellent color and purity of 99.9% or more by using crude 2,6-naphthalene dicarboxylic acid. And more particularly, the present invention relates to a method for separating and refining 2,6-naphthalene dicarboxylic acid, in which adjustment of pressure and temperature during multiple-step crystallization process enables controlling nucleation and the crystal growth rate, thereby allowing a particle size distribution and form to be controlled.

Abstract: The present invention relates to a process for preparing polyethylene naphthalate, comprising the steps of: esterifying 2,6-naphthalene dicarboxylic acid and ethylene glycol, or glycols using the two materials as major material to obtain prepolymer which comprises bis(beta-hydroxyethyl)naphthalate or low polymer as main material; and performing polycondensation reaction to thereby prepare polyethylene naphthalate. The process of the present invention has advantages of: enabling esterification with a low molar ratio of ethylene glycol to reduce reaction time, thereby increasing process efficiency; minimizing formation of side reaction products to improve properties; and preventing deterioration of the products by performing polycondensation at a low temperature to thereby obtain polyethylene naphthalate polymers of high quality.

Abstract: High-purity 2,6-dimethylnaphthalene is prepared by (1) subjecting a dimethylnaphthalene isomer mixture rich in 1,5-dimethylnaphthalene, high boiling point materials, unreacted 1,5-dimethyltetralin, and low boiling point materials, which are produced from a dehydrogenation reaction of 1,5-dimethyltetralin, to separation, using a distillation column; subjecting the dimethylnaphthalene mixture separated by the distillation column to liquid state isomerization in the presence of an isomerization catalyst; (3) a first crystallization (melt crystallization process) by cooling the product of liquid state isomerization with a refrigerant without a solvent to form crystals; and (4) a second crystallization (solution crystallization process) of mixing the crystals of the first crystallization step with a solvent to form crystals.

Abstract: The present invention relates to a method for achieving high purity separation and refinement by controlling morphology and particle size of 2,6-dimethylnaphthalene. And more particularly, the present invention relates to a method for obtaining high purity 2,6-dimethylnaphthalene crystals, in which crystallization is carried out with a solvent that enables the crystals to form a square-platy shape. During the process, crystallization variables such as, stirring speed, cooling speed, solvent and composition ratio, are adjusted to control morphology and particle size of 2,6-dimethylnaphthalene and to remove aggregation, thereby obtaining 2,6-dimethylnaphthalene crystals of high purity.

Abstract: Disclosed herein is a process of producing high purity and high yield dimethylnaphthalene by dehydrogenating a dimethyltetralin isomer using a metal catalyst for dehydrogenation. The metal catalyst contains a carrier selected from alumina (Al2O3), silica (SiO2), a silica-alumina mixture and zeolite. The metal catalyst also contains 0.05 to 2.5% by weight of platinum (Pt), 0.1 to 3.0% by weight of tin (Sn) or indium (In), 0.5 to 15.0% by weight of at least one selected from the group consisting of potassium (K), magnesium (Mg) and cesium (Cs), 0.3 to 3.0% by weight of chlorine, and 0.01 to 3.0 % by weight of zinc (Zn) or gallium (Ga) as active components based on an element weight of the final catalyst.

Abstract: Disclosed is a method for purifying 2,6-naphthalenedicarboxylic acid (NDA) that is present in a solid state in a solution. According to the method, sintered metal membrane filtration units are used to efficiently separate and purify 2,6-naphthalenedicarboxylic acid separated after hydrogenation and crystallization in a continuous process. An apparatus for implementing the method is further provided.

Abstract: Provided is a method for the separation and purification of high-purity 2,6-dimethylnaphthalene from a reaction mixture of dimethylnaphthalenes by continuous crystallization. According to the method, shell-tubetype crystallization apparatuses are used to perform crystallization operations under a continuous flow of a reaction mixture of dimethylnaphthalenes, which is obtained from the synthesis of dimethylnaphthalenes using o-xylene and butadiene as starting materials. As a result, high-purity 2,6-dimethylnaphthalene is separated and purified in a high yield from the reaction mixture. In addition, the method is advantageous in terms of energy saving when compared to conventional separation methods and enables continuous separation and purification of 2,6-dimethylnaphthalene on an industrial scale. A system for implementing the method is further provided.

Abstract: A method for separating and purifying 2,6-dimethylnaphthalene, is provided in which 2,6-dimethylnaphthalene of high purity is obtained from a mixture of dimethylnaphthalene isomers with a high yield, by means of a combined process of column melt crystallization and sweating operation.

Abstract: An apparatus and a method for effectively recovering acetic acid and catalyst from a mother liquor discharged from a series of processes including an oxidation process, a crystallization process and a solid-liquid separation process, in a continuous process for preparing naphthalenedicarboxylic acid by oxidizing dimethylnaphthalene in the presence of an oxygen-containing gas and an acetic acid solvent, using a catalyst system comprising a transition metal such as cobalt or manganese, and a bromine-based compound, are provided.

Abstract: The present invention relates to a process of hydrogenation reaction of 2,6-naphthalenedicarboxylic acid comprising the steps of calculating an amount of hydrogen to remove impurities such as formylnaphthoic acid, naphthalenecarboxylate bromide and high molecule organic impurities of heavy substances, and inputting a fixed quantity of hydrogen calculated. Consequently, higher purity 2,6-naphthalenedicarboxylic acid may be obtained in high yield.

Abstract: Disclosed herein is a process of producing high purity and high yield dimethylnaphthalene by dehydrogenating a dimethyltetralin isomer using a metal catalyst for dehydrogenation. The metal catalyst contains a carrier selected from alumina (Al2O3), silica (SiO2), a silica-alumina mixture and zeolite. The metal catalyst also contains 0.05 to 2.5% by weight of platinum (Pt), 0.1 to 3.0% by weight of tin (Sn) or indium (In), 0.5 to 15.0% by weight of at least one selected from the group consisting of potassium (K), magnesium (Mg) and cesium (Cs), 0.3 to 3.0% by weight of chlorine, and 0.01 to 3.0 % by weight of zinc (Zn) or gallium (Ga) as active components based on an element weight of the final catalyst.

Abstract: The present invention relates to a method for preparation, separation and purification of high-purity 2,6-dimethylnaphthalene. The method according to the present invention comprises a step of subjecting a dimethylnaphthalene isomer mixture rich in 1,5-dimethylnaphthalene, high boiling point materials, unreacted 1,5-dimethyltetralin, and low boiling point materials, which are produced from a dehydrogenation reaction of 1,5-dimethyltetralin, to separation, using a distillation column; a step of subjecting the dimethylnaphthalene mixture separated by the distillation column to liquid state isomerization in the presence of an isomerization catalyst; a first crystallization step (melt crystallization process) of cooling the product of liquid state isomerization with a refrigerant without a solvent to form crystals; and a second crystallization step (solution crystallization process) of mixing the product of the first crystallization step with a solvent to form crystals.

Abstract: An apparatus and a method for effectively recovering acetic acid and catalyst from a mother liquor discharged from a series of processes including an oxidation process, a crystallization process and a solid-liquid separation process, in a continuous process for preparing naphthalenedicarboxylic acid by oxidizing dimethylnaphthalene in the presence of an oxygen-containing gas and an acetic acid solvent, using a catalyst system comprising a transition metal such as cobalt or manganese, and a bromine-based compound, are provided.

Abstract: A method for separating and purifying 2,6-dimethylnaphthalene, is provided in which 2,6-dimethylnaphthalene of high purity is obtained from a mixture of dimethylnaphthalene isomers with a high yield, by means of a combined process of column melt crystallization and sweating operation.