Abstract: Disclosed are a method and an apparatus for preparing a polycrystalline silicon rod using a mixed core means, comprising: installing a first core means made of a resistive material together with a second core means made of silicon material in an inner space of a deposition reactor; electrically heating the first core means and pre-heating the second core by the first core means which is electrically heated; electrically heating the preheated second core means; and supplying a reaction gas into the inner space in a state where the first core means and the second core means are electrically heated for silicon deposition.

Abstract: Disclosed herein is a method of preparing ZSM-5, including: providing a nanocrystalline ZSM-5 seed having a size of 70˜300 nm; adding the nanocrystalline ZSM-5 seed to a stock solution including water glass as a silica source, an alumina source, a neutralizer and water to form a reaction mixture; and maintaining the reaction mixture at 150˜200° C. to crystallize the reaction mixture. The method is advantageous in that ZSM-5 having small and uniform crystal sizes and including no impurities can be synthesized in a short period of time.

Abstract: A method for preparing a polysilicon rod using a metallic core means, including: installing a core means in an inner space of a deposition reactor used for preparing a silicon rod, the core means being constituted by forming at least one separation layer on the surface of a metallic core element and being connected to an electrode means, heating the core means by supplying electricity through the electrode means, and supplying a reaction gas into the inner space for silicon deposition, thereby forming a deposition output in an outward direction on the surface of the core means. The deposition output and the core means can be separated easily from the silicon rod output obtained by the process of silicon deposition, and the contamination of the deposition output caused by impurities of the metallic core element can be minimized, thereby a high-purity silicon can be prepared more economically and conveniently.

Abstract: The present invention relates to a cation-exchanged zeolite catalyst for an transiodination and a process for producing mono-iodo benzene by using it. Particularly, the cation-exchanged zeolite catalyst has a molar ratio of Si/Al from 5 to 100 and is ion-exchanged with an alkali metal or an alkaline earth metal in range of 2% to 50% of ion exchange capacity. Further, the process for producing mono-iodo benzene of the present invention comprises the step of performing a transiodination by using the cation-exchanged zeolite catalyst to produce mono-iodo benzene from reactants including benzene and one or more multi-iodo benzenes selected from the group consisting of di-iodo benzene and tri-iodo benzene.

Abstract: The present invention relates to a high-pressure fluidized bed reactor for preparing granular polycrystalline silicon, comprising (a) a reactor tube, (b) a reactor shell encompassing the reactor tube, (c) an inner zone formed within the reactor tube, where a silicon particle bed is formed and silicon deposition occurs, and an outer zone formed in between the reactor shell and the reactor tube, which is maintained under the inert gas atmosphere, and (d) a controlling means to keep the difference between pressures in the inner zone and the outer zone being maintained within the range of 0 to 1 bar, thereby enabling to maintain physical stability of the reactor tube and efficiently prepare granular polycrystalline silicon even at relatively high reaction pressure.

Abstract: There is provided a method for continual preparation of granular polycrystalline silicon using a fluidized bed reactor, enabling a stable, long-term operation of the reactor by effective removal of silicon deposit accumulated on the inner wall of the reactor tube. The method comprises (i) a silicon particle preparation step, wherein silicon deposition occurs on the surface of the silicon particles, while silicon deposit is accumulated on the inner wall of the reactor tube encompassing the reaction zone; (ii) a silicon particle partial discharging step, wherein a part of the silicon particles remaining inside the reactor tube is discharged out of the fluidized bed reactor so that the height of the bed of the silicon particles does not exceed the height of the reaction gas outlet; and (iii) a silicon deposit removal step, wherein the silicon deposit is removed by supplying an etching gas into the reaction zone.

Abstract: The present invention relates to a high-pressure fluidized bed reactor for preparing granular polycrystalline silicon, comprising (a) a reactor tube, (b) a reactor shell encompassing the reactor tube, (c) an inner zone formed within the reactor tube, where a silicon particle bed is formed and silicon deposition occurs, and an outer zone formed in between the reactor shell and the reactor tube, which is maintained under the inert gas atmosphere, and (d) a controlling means to keep the difference between pressures in the inner zone and the outer zone being maintained within the range of 0 to 1 bar, thereby enabling to maintain physical stability of the reactor tube and efficiently prepare granular polycrystalline silicon even at relatively high reaction pressure.

Abstract: The present invention relates to a method for preparing a polysilicon rod using a metallic core means, comprising: installing a core means in an inner space of a deposition reactor used for preparing a silicon rod, wherein the core means is constituted by forming one or a plurality of separation layer(s) on the surface of a metallic core element and is connected to an electrode means; heating the core means by supplying electricity through the electrode means; and supplying a reaction gas into the inner space for silicon deposition, thereby forming a deposition output in an outward direction on the surface of the core means. According to the present invention, the deposition output and the core means can be separated easily from the silicon rod output obtained by the process of silicon deposition, and the contamination of the deposition output caused by impurities of the metallic core element can be minimized, thereby a high-purity silicon can be prepared in a more economic and convenient way.

Abstract: The present invention relates to a method of preparing mono-iodo benzene with a transiodination reaction, and more preferably a method of preparing mono-iodo benzene including a step of performing transiodination of a reactant including benzene and at least a multi-iodo benzene selected from the group consisting of di-iodo benzene and tri-iodo benzene with an HY or HBeta type of zeolite having a Si/Al molar ratio of 10 to 100 as a catalyst. The method of the present invention has an advantage that iodine is recovered from by-products including m-di-iodo benzene, o-di-iodo benzene, and tri-iodo benzene obtained in the process of preparing p-di-iodo benzene, thereby resulting in minimizing the loss of iodine.

Abstract: The present invention relates to a method for preparing a polysilicon rod using a metallic core means, comprising: installing a core means in an inner space of a deposition reactor used for preparing a silicon rod, wherein the core means (C) is constituted by forming one or a plurality of separation layer(s) on the surface of a metallic core element and is connected to an electrode means (E), heating the core means (C) by supplying electricity through the electrode means (E), and supplying a reaction gas (Gf) into the inner space (Ri) for silicon deposition, thereby forming a deposition output in an outward direction on the surface of the core means (C).

Abstract: The present invention relates to a method for mass preparation of granular polycrystalline silicon in a fluidized bed reactor, comprising (a) a reactor tube, (b) a reactor shell encompassing the reactor tube, (c) an inner zone formed within the reactor tube, where a silicon particle bed is formed and silicon deposition occurs, and an outer zone formed in between the reactor shell and the reactor tube, which is maintained under an inert gas atmosphere, and (d) a controlling means to keep the pressure difference between the inner zone and the outer zone being maintained within the range of 0 to 1 bar, thereby capable of maintaining physical stability of the reactor tube and efficiently preparing granular polycrystalline silicon even at a relatively high reaction pressure.

Abstract: Disclosed is a process for producing light olefins from hydrocarbon feedstock. The process is characterized in that a porous molecular sieve catalyst consisting of a product obtained by evaporating water from a raw material mixture comprising a molecular sieve with a framework of Si—OH—Al— groups, a water-insoluble metal salt, and a phosphate compound, is used to produce light olefins, particularly ethylene and propylene, from hydrocarbon, while maintaining excellent selectivity to light olefins. According to the process, by the use of a specific catalyst with hydrothermal stability, light olefins can be selectively produced in high yield with high selectivity from hydrocarbon feedstock, particularly full-range naphtha. In particular, the process can maintain higher cracking activity than the reaction temperature required in the prior thermal cracking process for the production of light olefins, and thus, can produce light olefins with high selectivity and conversion from hydrocarbon feedstock.

Abstract: The present invention relates to a method of preparing mono-iodo benzene with a transiodination reaction, and more preferably a method of preparing mono-iodo benzene including a step of performing transiodination of a reactant including benzene and at least a multi-iodo benzene selected from the group consisting of di-iodo benzene and tri-iodo benzene with an HY or HBeta type of zeolite having a Si/Al molar ratio of 10 to 100 as a catalyst. The method of the present invention has an advantage that iodine is recovered from by-products including m-di-iodo benzene, o-di-iodo benzene, and tri-iodo benzene obtained in the process of preparing p-di-iodo benzene, thereby resulting in minimizing the loss of iodine.

Abstract: A process for preparing granular polysilicon using a fluidized bed reactor is disclosed. The upper and lower spaces of the bed are defined as a reaction zone and a heating zone, respectively, with the height of the reaction gas outlet being selected as the reference height. The invention maximizes the reactor productivity by sufficiently providing the heat required and stably maintaining the reaction temperature in the reaction zone, without impairing the mechanical stability of the fluidized bed reactor. This is achieved through electrical resistance heating in the heating zone where an internal heater is installed in a space in between the reaction gas supplying means and the inner wall of the reactor tube, thereby heating the fluidizing gas and the silicon particles in the heating zone.

Abstract: There is provided a method for continual preparation of granular polycrystalline silicon using a fluidized bed reactor, enabling a stable, long-term operation of the reactor by effective removal of silicon deposit accumulated on the inner wall of the reactor tube. The method comprises (i) a silicon particle preparation step, wherein silicon deposition occurs on the surface of the silicon particles, while silicon deposit is accumulated on the inner wall of the reactor tube encompassing the reaction zone; (ii) a silicon particle partial discharging step, wherein a part of the silicon particles remaining inside the reactor tube is discharged out of the fluidized bed reactor so that the height of the bed of the silicon particles does not exceed the height of the reaction gas outlet; and (iii) a silicon deposit removal step, wherein the silicon deposit is removed by supplying an etching gas into the reaction zone.

Abstract: The present invention relates to a high-pressure fluidized bed reactor for preparing granular polycrystalline silicon, comprising (a) a reactor tube, (b) a reactor shell encompassing the reactor tube, (c) an inner zone formed within the reactor tube, where a silicon particle bed is formed and silicon deposition occurs, and an outer zone formed in between the reactor shell and the reactor tube, which is maintained under the inert gas atmosphere, and (d) a controlling means to keep the difference between pressures in the inner zone and the outer zone being maintained within the range of 0 to 1 bar, thereby enabling to maintain physical stability of the reactor tube and efficiently prepare granular polycrystalline silicon even at relatively high reaction pressure.

Abstract: The present invention relates to a method for preparing a polysilicon rod using a metallic core means, comprising: installing a core means in an inner space of a deposition reactor used for preparing a silicon rod, wherein the core means is constituted by forming one or a plurality of separation layer(s) on the surface of a metallic core element and is connected to an electrode means; heating the core means by supplying electricity through the electrode means; and supplying a reaction gas into the inner space for silicon deposition, thereby forming a deposition output in an outward direction on the surface of the core means. According to the present invention, the deposition output and the core means can be separated easily from the silicon rod output obtained by the process of silicon deposition, and the contamination of the deposition output caused by impurities of the metallic core element can be minimized, thereby a high-purity silicon can be prepared in a more economic and convenient way.

Abstract: Disclosed are a method and an apparatus for preparing a polycrystalline silicon rod using a mixed core means, comprising: installing a first core means made of a resistive material together with a second core means made of silicon material in an inner space of a deposition reactor; electrically heating the first core means and pre-heating the second core by the first core means which is electrically heated; electrically heating the preheated second core means; and supplying a reaction gas into the inner space in a state where the first core means and the second core means are electrically heated for silicon deposition.

Abstract: A porous solid acid catalyst for producing light olefins is prepared through pillaring and a solid state reaction of a raw material mixture. The catalyst is made of a porous material having a crystalline structure that is different from that of the raw material mixture. The catalyst exhibits excellent catalytic activity (i.e., conversion and selectivity) in the production of light olefins from hydrocarbon feeds such as full range naphthas.

Abstract: A porous solid acid catalyst for producing light olefins is prepared through pillaring and a solid state reaction of a raw material mixture. The catalyst is made of a porous material having a crystalline structure that is different from that of the raw material mixture. The catalyst exhibits excellent catalytic activity (i.e., conversion and selectivity) in the production of light olefins from hydrocarbon feeds such as full range naphthas.