Abstract: A method for separating and refining 1-butene with a high purity and a high yield from a raffinate-2 stream. The method includes: feeding raffinate-2 to a first distillation column; obtaining heavy raffinate-3 from a lower part of the first distillation column; recovering an upper part fraction containing 1-butene from an upper part of the first distillation column; feeding the upper part fraction containing 1-butene to a second distillation column; recovering a first lower part fraction rich in 1-butene from a lower part of the second distillation column and light raffinate-3 from an upper part of the second distillation column. Heat of the upper part fraction recovered from the upper part of the first distillation column is fed to the lower part of the second distillation column through a first heat exchanger. Thus, 1-butene is obtained with high purity and high yield while maximizing an energy recovery amount by double-effect distillation.

Abstract: The present disclosure relates to a method and a system for manufacturing an ester-based composition which are characterized in sequentially operating a plurality of batch reactors, and since an ester-based composition is semi-continuously manufactured, the productivity is high and the stability of a batch reactor is secured.

Abstract: The present disclosure relates to a manufacturing system and a manufacturing method which are capable of continuously manufacturing an ester-based composition, and has a technical feature of being capable of manufacturing an ether-based composition continuously, economically, and efficiently.

Abstract: A conversation topic providing method includes: converting voice data, of a conversation of a user who is on a phone, into text; selecting a keyword, indicating an intention of the user, from the text; obtaining information of interest with respect to the keyword; and determining topics relating to the keyword based on user information.

Abstract: Provided is a method for manufacturing a terephthalate-based composition, the method comprising: a step (S1) of flowing in a dialkyl terephthalate in which alkyl has 7 to 10 carbon atoms and a primary alcohol with a low boiling point having 4 or 5 carbon atoms into a reactor and performing transesterification of the dialkyl terephthalate and the primary alcohol with a low boiling point and a step (S2) of extracting in a reduced pressure an unreacted material and a by-product from the reactor after finishing the transesterification, wherein the step S1 comprises a pressure-applying step in which the pressure of the reactor is 1.5 to 2.5 bar.

Abstract: An ophthalmic device includes an optic including an optic axis and a closed-loop haptic structure coupled to the optic via a frame surrounding the optic, the closed-loop haptic structure including a closed loop extending from first and second attachment points to the frame. The closed loop includes a first hinge and a second hinge. The first hinge has a first section having a first component extending in a first angular direction, a second section having a second component extending in a second angular direction opposite to the first angular direction, and a first connecting section between the first section and the second section. The second hinge has a third section having a third component extending in the second angular direction, a fourth section having a fourth component extending in the first angular direction, the fourth section being connected to the second section to form the closed loop.

Abstract: The present disclosure relates to a method and a system for manufacturing an ester-based composition which are characterized in sequentially operating a plurality of batch reactors, and since an ester-based composition is semi-continuously manufactured, the productivity is high and the stability of a batch reactor is secured.

Abstract: The present disclosure relates to a manufacturing system and a manufacturing method which are capable of continuously manufacturing an ester-based composition, and has a technical feature of being capable of manufacturing an ether-based composition continuously, economically, and efficiently.

Abstract: A distillation device including: a first distillation column having first top, bottom and upper outlets and first upper and lower inlets; a second distillation column equipped with a top condenser and a bottom reboiler, and having second top, bottom and upper outlets and second upper and lower inlets; a vapor recompressor; a heat exchanger; a first supply line supplying a feedstock to the first lower inlet; a first connection line transferring a first bottom flow to the second lower inlet via the heat exchanger; and a second connection line transferring a second top flow to the top condenser via the heat exchanger after passing through the vapor recompressor. The first bottom flow flowing through the first connection line and the second top flow flowing through the second connection line are heat-exchanged in the heat exchanger. A distillation method of a feedstock using the distillation device.

Abstract: Provided is a monohydric alcohol removal method in esterification, the method including a step of reacting a carbonyl-based compound having one or more functional groups selected from the group consisting of carboxyl, ester, and acid anhydride groups with a monohydric alcohol in an esterification reactor including a liquid phase outlet line connected to a liquid phase section in the reactor, and a step of separating in a gas-liquid separation column to remove the monohydric alcohol, wherein the inflow of a liquid phase stream into the gas-liquid separation column starts at the time point between 10% and 70% of the total time required for the gas-liquid separation.

Abstract: Provided is a method of separating and purifying a mixture of components having small difference in boiling point, and the method may maximize an energy collecting amount and collect a product to be desired in high purity and high yield.

Abstract: An ophthalmic device includes an optic including an optic axis and a closed-loop haptic structure coupled to the optic via a frame surrounding the optic, the closed-loop haptic structure including a closed loop extending from first and second attachment points to the frame. The closed loop includes a first hinge and a second hinge. The first hinge has a first section having a first component extending in a first angular direction, a second section having a second component extending in a second angular direction opposite to the first angular direction, and a first connecting section between the first section and the second section. The second hinge has a third section having a third component extending in the second angular direction, a fourth section having a fourth component extending in the first angular direction, the fourth section being connected to the second section to form the closed loop.

Abstract: A conversation topic providing method includes: converting voice data, of a conversation of a user who is on a phone, into text; selecting a keyword, indicating an intention of the user, from the text; obtaining information of interest with respect to the keyword; and determining topics relating to the keyword based on user information.

Abstract: Provided is a method of separating and refining 1-butene with a high purity and a high yield from a raffinate-2 stream, and recovering the refined 1-butene while maximizing an energy saving rate by using a high efficiency distillation column installed with a separation wall.

Abstract: The present disclosure relates to a system and a method for continuously purifying a reaction product of esterification, where the system includes a neutralizer, a distiller, and a product purifier. Through the present system and the method, it is possible to perform a continuous purification process efficiently, and to reduce lower alcohol wastewater generated during purification.

Abstract: A method for vaporizing liquid propane to be supplied as a raw material to a naphtha cracking ractor. The method comprises: decompressing liquid propane to lower a vaporization point and vaporize at least a portion of the liquid propane; utilizing vaporization heat, generated during vaporization of the portion of liquid propane, as a refrigerant; compressing the vaporized propane gas to increase pressure of the propane gas and produce compressed propane gas; and preheating the compressed propane gas. By using this method, it is possible to reduce pressure of liquid propane to a significantly lower pressure than the related art method so that all the vaporization latent heat or vaporization heat included in liquid propane may be utilized as a refrigerant, while also reducing heat energy consumed in a preheat process before it is supplied to the naphtha cracking reactor.

Abstract: The purification method of isopropyl alcohol including: feeding a feed including isopropyl alcohol, water, and a byproduct comprising normal propyl alcohol to an azeotropic distillation purification tower; separating an azeotrope comprising isopropyl alcohol, normal-propyl alcohol, and water from the top of the azeotropic distillation purification tower and feeding the azeotrope to a dehydration tower; separating the isopropyl alcohol and the normal-propyl alcohol from the bottom of the dehydration tower and feeding the isopropyl alcohol and the normal-propyl alcohol to a normal-propyl alcohol purification tower; and separating the isopropyl alcohol from the top of the normal propyl alcohol purification tower.

Abstract: The present application relates to a selective distillation apparatus and a distillation method, which provides a distillation apparatus capable of switching between a serial connection mode and a parallel connection mode on the situation, thereby enabling selective operation of high-efficiency operation and high-capacity operation.

Abstract: Provided is a monohydric alcohol removal method in esterification, the method including a step of reacting a carbonyl-based compound having one or more functional groups selected from the group consisting of carboxyl, ester, and acid anhydride groups with a monohydric alcohol in an esterification reactor including a liquid phase outlet line connected to a liquid phase compartment in the reactor, and a step of separating in a gas-liquid separation column to remove the monohydric alcohol, wherein the inflow of a liquid phase stream into the gas-liquid separation column starts at the time point between 10% and 70% of the total time required for the gas-liquid separation.

Abstract: The present invention provides an ethylene separation process comprising an first and second deethanizer columns and an acetylene converter, thereby providing an ethylene stream having a purity of 99 wt % or more to the middle of an ethylene separation column. The present invention increases the production amount of ethylene and also reduces energy consumption by passing the feed through a preliminary ethylene separation process, without having to change existing facilities in which an acetylene converter is provided downstream of the deethanizer column.