Abstract: A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards a buried waveguide as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within a cladding layer. In some examples, at least one waveguide tapers along its length. In some examples, at least one waveguide includes spaced-apart segments arranged to form a subwavelength grating (SWG) configured to entrain electromagnetic radiation.

Abstract: A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards a buried waveguide as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within a cladding layer. In some examples, at least one waveguide tapers along its length. In some examples, at least one waveguide includes spaced-apart segments arranged to form a subwavelength grating (SWG) configured to entrain electromagnetic radiation.

Abstract: A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards the substrate as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within corresponding cladding layers. A first waveguide extends farther from the facet in the longitudinal direction than does a second waveguide. The second waveguide is located farther above the silicon substrate than is the first waveguide. The coupler can include a stack of waveguide assemblies. A lower waveguide assembly can include one waveguide. An intermediate or upper waveguide assembly can include multiple waveguides. In some examples, at least one waveguide tapers along its length.

Abstract: Disclosed is a method for directly synthesizing monocyclic aromatic compounds and long-chain olefin compounds from a carbon dioxide-rich synthetic gas and, specifically, a method for directly synthesizing monocyclic aromatic compounds and long-chain olefin compounds from a carbon dioxide-rich synthetic gas, the method comprising a step of preparing a C1-C15 short-chain hydrocarbon by Fischer-Tropsch (FT) synthesis and a step of preparing monocyclic aromatic compounds and long-chain olefin compounds by dehydrogenating the short-chain hydrocarbon products, and maximizing the yield of the short-chain hydrocarbon by using, as a synthetic gas to be used in FT synthesis, a carbon dioxide-rich synthetic gas in which the molar ratio of hydrogen, carbon monoxide and carbon dioxide is delimited to a specific range, and maximizing the yield of the monocyclic aromatic compounds or the long-chain olefin compounds by specifying the composition of a catalyst to be used in the dehydrogenation and the temperature and pressure

Abstract: A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards the substrate as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within corresponding cladding layers. A first waveguide extends farther from the facet in the longitudinal direction than does a second waveguide. The second waveguide is located farther above the silicon substrate than is the first waveguide. The coupler can include a stack of waveguide assemblies. A lower waveguide assembly can include one waveguide. An intermediate or upper waveguide assembly can include multiple waveguides. In some examples, at least one waveguide tapers along its length.

Abstract: A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards a buried waveguide as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within a cladding layer. In some examples, at least one waveguide tapers along its length. In some examples, at least one waveguide includes spaced-apart segments arranged to form a subwavelength grating (SWG) configured to entrain electromagnetic radiation.

Abstract: A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards a buried waveguide as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within a cladding layer. In some examples, at least one waveguide tapers along its length. In some examples, at least one waveguide includes spaced-apart segments arranged to form a subwavelength grating (SWG) configured to entrain electromagnetic radiation.

Abstract: A semiconductor photonic device includes a substrate, facet(s), and optical coupler(s) associated with the facet(s). Each optical coupler can couple an electromagnetic field incident on the respective facet towards the substrate as the electromagnetic field proceeds into the semiconductor photonic device. In some examples, each coupler has waveguides extending in a longitudinal direction and at least partly encapsulated within corresponding cladding layers. A first waveguide extends farther from the facet in the longitudinal direction than does a second waveguide. The second waveguide is located farther above the silicon substrate than is the first waveguide. The coupler can include a stack of waveguide assemblies. A lower waveguide assembly can include one waveguide. An intermediate or upper waveguide assembly can include multiple waveguides. In some examples, at least one waveguide tapers along its length.

Abstract: Disclosed is a method for directly synthesizing monocyclic aromatic compounds and long-chain olefin compounds from a carbon dioxide-rich synthetic gas and, specifically, a method for directly synthesizing monocyclic aromatic compounds and long-chain olefin compounds from a carbon dioxide-rich synthetic gas, the method comprising a step of preparing a C1-C15 short-chain hydrocarbon by Fischer-Tropsch (FT) synthesis and a step of preparing monocyclic aromatic compounds and long-chain olefin compounds by dehydrogenating the short-chain hydrocarbon products, and maximizing the yield of the short-chain hydrocarbon by using, as a synthetic gas to be used in FT synthesis, a carbon dioxide-rich synthetic gas in which the molar ratio of hydrogen, carbon monoxide and carbon dioxide is delimited to a specific range, and maximizing the yield of the monocyclic aromatic compounds or the long-chain olefin compounds by specifying the composition of a catalyst to be used in the dehydrogenation and the temperature and pressure

Abstract: The present invention relates to a method for producing the activated catalyst for Fischer-Tropsch synthesis comprising: a first step of reducing a catalyst for Fischer-Tropsch synthesis; a second step of preparing liquid hydrocarbon in which a part or all of molecular oxygen is eliminated; and a third step of introducing the reduced catalyst prepared in the first step into the liquid hydrocarbon prepared in the second step while blocking its contact with air. Since the reduced catalyst used for Fischer-Tropsch synthesis is introduced into liquid hydrocarbon from which molecular oxygen is removed or coated by liquid hydrocarbon, the catalyst for Fischer-Tropsch synthesis activated based on the present invention maintains a high activity even if exposed to the air for a long time, thereby easily facilitating the long-term storage and long-distance transfer of the reduced catalyst.

Abstract: The present invention relates to a process of preparing of a phosphorus-containing phosphorus-alumina support by a sol-gel method and a cobalt/phosphorus-alumina catalyst where cobalt is supported onto the phosphorus-alumina support as an active ingredient. The phosphorus-alumina support is prepared by a sol-gel method and has wide specific surface area with bimodal pore size distribution and high cobalt dispersion, thereby enabling to increase heat and mass transfer, stabilize the structure by modifying the surface property of alumina and decrease the deactivation rate due to the reduced oxidation of cobalt component during the F-T reaction. When Fischer-Tropsch reaction (F-T) is conducted on the catalyst, the catalyst maintains a superior thermal stability, inhibits the deactivation due to water generation during the F-T reaction and also causes relatively high conversion of carbon monoxide and stable selectivity of liquid hydrocarbons.

Abstract: The present invention relates to a method for producing the activated catalyst for Fischer-Tropsch synthesis comprising: a first step of reducing a catalyst for Fischer-Tropsch synthesis; a second step of preparing liquid hydrocarbon in which a part or all of molecular oxygen is eliminated; and a third step of introducing the reduced catalyst prepared in the first step into the liquid hydrocarbon prepared in the second step while blocking its contact with air. Since the reduced catalyst used for Fischer-Tropsch synthesis is introduced into liquid hydrocarbon from which molecular oxygen is removed or coated by liquid hydrocarbon, the catalyst for Fischer-Tropsch synthesis activated based on the present invention maintains a high activity even if exposed to the air for a long time, thereby easily facilitating the long-term storage and long-distance transfer of the reduced catalyst.

Abstract: Provided is a preparation method for a mesoporous zeolite, particularly a method for preparing mesoporous zeolite through a simple process without using costly materials such as an organic amine template or a surfactant. The method includes 1) forming a synthetic zeolite gel by mixing a silica precursor, an aluminum precursor and water and aging the resulted mixture; 2) carrying out zeolite synthesis by subjecting the synthetic zeolite gel to a hydrothermal reaction; 3) cooling the synthesized zeolite from the above step 2), then adding a basic solution thereto and allowing them to react, thereby obtaining a mesoporous zeolite slurry; and 4) washing the mesoporous zeolite slurry with water, drying and firing it, thereby obtaining a mesoporous zeolite.

Abstract: The present invention relates to: a catalyst activation method for Fischer-Tropsch synthesis; a catalyst regeneration method for Fischer-Tropsch synthesis; and a method for producing a liquid or solid hydrocarbon by using the Fischer-Tropsch synthesis reaction. The temperatures required for a metal carbide producing and activating reaction is markedly lower than existing catalyst activation temperatures, and the catalyst can be activated under conditions that are the same as Fischer-Tropsch synthesis reaction conditions, and thus there is no need for separate reduction equipment in the reactor, and a Fischer-Tropsch synthesis catalyst which has been used for a long time can be regenerated within the reactor without the catalyst being isolated or extracted from the reactor.

Abstract: The present invention relates to a catalyst for Fischer-Tropsch synthesis which has excellent heat transfer capability. This catalyst contains (1) central core particle or particles made of a heat transfer material (HTM) selected from the group consisting of a metal, a metal oxide, a ceramic, and a mixture thereof; and (2) outer particle layer which surrounds the central core particles and is attached to the surfaces of the central core particles by a binder material layer. The outer particle layer has a support and catalyst particles in a powder form containing metal particles disposed on the support. The catalyst having such a dual particle structure shows excellent heat transfer capability and, thus, exhibits high selectivity to a target hydrocarbon. Therefore, the catalyst of the present invention is useful in a fixed-bed reactor for Fischer-Tropsch synthesis for producing hydrocarbons from synthetic gas.

Abstract: The present invention relates to: a catalyst activation method for Fischer-Tropsch synthesis; a catalyst regeneration method for Fischer-Tropsch synthesis; and a method for producing a liquid or solid hydrocarbon by using the Fischer-Tropsch synthesis reaction. The temperatures required for a metal carbide producing and activating reaction is markedly lower than existing catalyst activation temperatures, and the catalyst can be activated under conditions that are the same as Fischer-Tropsch synthesis reaction conditions, and thus there is no need for separate reduction equipment in the reactor, and a Fischer-Tropsch synthesis catalyst which has been used for a long time can be regenerated within the reactor without the catalyst being isolated or extracted from the reactor.

Abstract: Disclosed is a method for methanol synthesis using synthesis gas obtained from reforming of natural gas with carbon dioxide. First, synthesis gas is obtained from steam carbon dioxide reforming of methane, in which steam reforming of natural gas is carried out simultaneously with carbon dioxide reforming of methane, by using a catalyst (Ni/Ce/MgAlOx, or Ni/Ce—Zr/MgAlOx) and processing condition capable of maintaining a predetermined ratio of carbon monoxide, carbon dioxide, and hydrogen [H2/(2CO+3CO2)=0.85-1.15]. Next, methanol synthesis is carried out by using the obtained synthesis gas and a catalyst system suitable for methanol synthesis with minimum byproduct formation (a catalyst system including a Cu—Zn—Al oxide containing CuO, ZnO, and Al2O3 at a predetermined ratio in combination with a cerium-zirconium oxide obtained by a sol-gel process).

Abstract: The provided is a preparation method of a mesoporous zeolite, particularly a method for preparing mesoporous zeolite through a simple process without using costly materials such as an organic amine template or a surfactant.

Abstract: The present invention relates to a process of preparing of a phosphorus-containing phosphorus-alumina support by a sol-gel method and a cobalt/phosphorus-alumina catalyst where cobalt is supported onto the phosphorus-alumina support as an active ingredient. The phosphorus-alumina support is prepared by a sol-gel method and has wide specific surface area with bimodal pore size distribution and high cobalt dispersion, thereby enabling to increase heat and mass transfer, stabilize the structure by modifying the surface property of alumina and decrease the deactivation rate due to the reduced oxidation of cobalt component during the F-T reaction. When Fischer-Tropsch reaction (F-T) is conducted on the catalyst, the catalyst maintains a superior thermal stability, inhibits the deactivation due to water generation during the F-T reaction and also causes relatively high conversion of carbon monoxide and stable selectivity of liquid hydrocarbons.

Abstract: The present invention relates to a catalyst for Fischer-Tropsch synthesis which has excellent heat transfer capability. This catalyst contains (1) central core particle or particles made of a heat transfer material (HTM) selected from the group consisting of a metal, a metal oxide, a ceramic, and a mixture thereof; and (2) outer particle layer which surrounds the central core particles and is attached to the surfaces of the central core particles by a binder material layer. The outer particle layer has a support and catalyst particles in a powder form containing metal particles disposed on the support. The catalyst having such a dual particle structure shows excellent heat transfer capability and, thus, exhibits high selectivity to a target hydrocarbon. Therefore, the catalyst of the present invention is useful in a fixed-bed reactor for Fischer-Tropsch synthesis for producing hydrocarbons from synthetic gas.