Abstract: The present invention relates to a method for selectively separating propylene carbonate by adding water to reaction products comprising a polyether carbonate polyol and propylene carbonate, which are generated from a polymerization reaction of propylene oxide and carbon dioxide under a double metal cyanide (DMC) catalyst, wherein an economical and effective separation of propylene carbonate can be achieved.

Abstract: The present invention relates to a double metal cyanide catalyst comprising a polyether compound, a metal salt, a metal cyanide salt, and an organic complexing agent having an acetate group or a tartrate group; a preparation method therefor; and a method for preparing a polycarbonate polyether polyol by copolymerizing carbon dioxide and an epoxy compound in the presence of the catalyst. According to the present invention, the double metal cyanide catalyst has excellent in catalytic activity and has a short catalytic activity induction time, according to an embodiment of the present invention, the process for preparing the catalyst of the present invention is eco-friendly and simple in process, since an amount of the organic complexing agent to be used is small, and has a simple process.

Abstract: The present invention relates to a method for selectively separating propylene carbonate by adding water to reaction products comprising a polyether carbonate polyol and propylene carbonate, which are generated from a polymerization reaction of propylene oxide and carbon dioxide under a double metal cyanide (DMC) catalyst, wherein an economical and effective separation of propylene carbonate can be achieved.

Abstract: An apparatus for separating dimethyl carbonate using pervaporation includes: an atmospheric distillation column and a high pressure distillation column distilling a mixture containing dimethyl carbonate and methanol and separating dimethyl carbonate from the mixture; and a pervaporation membrane module disposed between the atmospheric distillation column and the high pressure distillation column and allowing for permeation of the methanol to separate the methanol from the mixture, thereby reducing heat consumption and a process cost as compared to the case of only using an existing pressure swing distillation method.

Abstract: The present invention relates to a double metal cyanide catalyst comprising a polyether compound, a metal salt, a metal cyanide salt, and an organic complexing agent having an acetate group or a tartrate group; a preparation method therefor; and a method for preparing a polycarbonate polyether polyol by copolymerizing carbon dioxide and an epoxy compound in the presence of the catalyst. According to the present invention, the double metal cyanide catalyst has excellent in catalytic activity and has a short catalytic activity induction time, according to an embodiment of the present invention, the process for preparing the catalyst of the present invention is eco-friendly and simple in process, since an amount of the organic complexing agent to be used is small, and has a simple process.

Abstract: An apparatus for separating dimethyl carbonate using pervaporation includes: an atmospheric distillation column and a high pressure distillation column distilling a mixture containing dimethyl carbonate and methanol and separating dimethyl carbonate from the mixture; and a pervaporation membrane module disposed between the atmospheric distillation column and the high pressure distillation column and allowing for permeation of the methanol to separate the methanol from the mixture, thereby reducing heat consumption and a process cost as compared to the case of only using an existing pressure swing distillation method.

Abstract: Disclosed is a method for preparing a dialkyl carbonate, in which a dialkyl carbonate such as dimethyl carbonate is economically prepared in an environmentally-friendly manner at a higher yield while reducing generation of a by-product. The method for preparing the dialkyl carbonate includes reacting urea, an alkyl carbamate having 1 to 3 carbon atoms, or a mixture thereof with a monovalent alcohol having 1 to 3 carbon atoms in the presence of a room temperature ionic liquid and a catalyst including a salt of a transition metal or a rare earth metal.

Abstract: Disclosed is a method for preparing a dialkyl carbonate, in which a dialkyl carbonate such as dimethyl carbonate is economically prepared in an environmentally-friendly manner at a higher yield while reducing generation of a by-product. The method for preparing the dialkyl carbonate includes reacting urea, an alkyl carbamate having 1 to 3 carbon atoms, or a mixture thereof with a monovalent alcohol having 1 to 3 carbon atoms in the presence of a room temperature ionic liquid and a catalyst including a salt of a transition metal or a rare earth metal.

Abstract: The present invention relates to a catalyst for removing nitrogen oxides from an exhaust gas, a method for preparing the same and a method for removing nitrogen oxide in an exhaust gas using the same, and more particularly, to a catalyst for removing nitrogen oxides from the exhaust gas in which a ceramic fiber carrier is treated by hydrothermal reaction prior to washcoating to improve the hydrothermal stability of catalyst, a method for preparing the same and a method for removing nitrogen oxide in an exhaust gas using the same. The catalyst prepared according to the present invention has excellent hydrothermal stability and an activity of the catalyst remains for a long time. Further, by using this catalyst to remove nitrogen oxides in an exhaust gas, a removal ratio of the nitrogen oxides is greatly enhanced.

Abstract: A catalyst made by the introduction of copper ions and cobalt ions into a Y-type zeolite to produce a CuCoY zeolite improves the reduction of NOx in exhaust from a lean burn engine, such as a diesel engine. A dual bed selective reduction reactor in the exhaust stream comprising a first bed of BaY or of Ag/alumina and a second bed of CuCoY is particularly effective in reduction of NOx. In one embodiment, the exhaust stream is suitably treated with an oxidant, such as ozone, and a reductant, such as a diesel hydrocarbon or oxygenated diesel hydrocarbon, before the exhaust passes in contact with the dual bed catalyst.

Abstract: The present invention relates to a catalyst for removal of nitrogen oxides from exhaust gas, a method of preparing the same and a method of removing nitrogen oxide in an exhaust gas using the same, and more particularly, to a catalyst for removal of nitrogen oxides from exhaust gas in which a ceramic fiber carrier is hydrothermal-treated prior to washcoating to improve the hydrothermal stability of catalyst, a method of preparing the same and a method of removing nitrogen oxide in an exhaust gas using the same. The catalyst prepared according to the present invention has excellent hydrothermal stability and an activity of the catalyst remains for a long time. Further, by using this catalyst to remove nitrogen oxides in an exhaust gas, a removal ratio of the nitrogen oxides is improved more.

Abstract: A catalyst made by the introduction of copper ions and cobalt ions into a Y-type zeolite to produce a CuCoY zeolite improves the reduction of NOx in exhaust from a lean burn engine, such as a diesel engine. A dual bed selective reduction reactor in the exhaust stream comprising a first bed of BaY or of Ag/alumina and a second bed of CuCoY is particularly effective in reduction of NOx. In one embodiment, the exhaust stream is suitably treated with an oxidant, such as ozone, and a reductant, such as a diesel hydrocarbon or oxygenated diesel hydrocarbon, before the exhaust passes in contact with the dual bed catalyst.

Abstract: A method for reducing nitrogen oxides including NO and NO2 in an exhaust stream also comprising oxygen, carbon monoxide and hydrocarbons at a temperature above about 150° C., the method including in embodiments oxidizing NO in the exhaust stream to NO2; reforming raw diesel fuel to produce OHC's from the fuel; adding diesel fuel hydrocarbons and their oxygenates to the exhaust stream for the reduction of nitrogen oxides; and contacting the exhaust stream with a reduction hybrid catalyst comprising BaY—Ag/Al2O3 to reduce the nitrogen oxides to N2. The method reduces NOx initially through the (HC+OHC)/SCR process producing N2, while also producing NH3 as a byproduct over Ag/Al2O3. The NH3 subsequently reduces NOx over the BaY—Ag/Al2O3 hybrid catalyst through the NH3/SCR process, producing more N2 and thereby enhancing the NOx reduction efficiency of the hybrid catalyst system.

Abstract: A catalyst made by the introduction of copper ions and cobalt ions into a Y-type zeolite to produce a CuCoY zeolite improves the reduction of NOx in exhaust from a lean bum engine, such as a diesel engine. A dual bed selective reduction reactor in the exhaust stream comprising a first bed of BaY or of Ag/alumina and a second bed of CuCoY is particularly effective in reduction of NOx. In one embodiment, the exhaust stream is suitably treated with an oxidant, such as ozone, and a reductant, such as a diesel hydrocarbon or oxygenated diesel hydrocarbon, before the exhaust passes in contact with the dual bed catalyst.

Abstract: A method for reducing nitrogen oxides including NO and NO2 in an exhaust stream also comprising oxygen, carbon monoxide and hydrocarbons at a temperature above about 150° C., the method including in embodiments oxidizing NO in the exhaust stream to NO2; reforming raw diesel fuel to produce OHC's from the fuel; adding diesel fuel hydrocarbons and their oxygenates to the exhaust stream for the reduction of nitrogen oxides; and contacting the exhaust stream with a reduction hybrid catalyst comprising BaY—Ag/Al2O3 to reduce the nitrogen oxides to N2. The method reduces NOx initially through the (HC+OHC)/SCR process producing N2, while also producing NH3 as a byproduct over Ag/Al2O3. The NH3 subsequently reduces NOx over the BaY-Ag/Al2O3 hybrid catalyst through the NH3/SCR process, producing more N2 and thereby enhancing the NOx reduction efficiency of the hybrid catalyst system.

Abstract: A zeolite catalyst and a process for preparing a zeolite catalyst which is both capable of catalyzing the removal of nitrogen oxides from a gaseous medium across a broad temperature range and is operationally and hydrothermally stable at high reaction temperatures. The zeolite catalyst includes a zeolite carrier having a mole ratio of typically from about 14 to about 95 and copper ions supported on the zeolite carrier. The zeolite catalyst is prepared by providing a zeolite carrier, reacting copper with the zeolite carrier by carrying out an ion exchange reaction in a cupric salt aqueous solution at a temperature of between about 4° C. and room temperature (25° C.), and then drying and calcining the catalyst.

Abstract: A zeolite catalyst and a process for preparing a zeolite catalyst which is both capable of catalyzing the removal of nitrogen oxides from a gaseous medium across a broad temperature range and is operationally and hydrothermally stable at high reaction temperatures. The zeolite catalyst includes a zeolite carrier having a mole ratio of typically from about 14 to about 95 and copper ions supported on the zeolite carrier. The zeolite catalyst is prepared by providing a zeolite carrier, reacting copper with the zeolite carrier by carrying out an ion exchange reaction in a cupric salt aqueous solution at a temperature of between about 4° C. and room temperature (25° C.), and then drying and calcining the catalyst.