Abstract: Disclosed is a heterogeneous catalyst for producing acetic acid by carbonylation of methanol. In the heterogeneous catalyst, a rhodium complex ion is ionically bonded to an insoluble catalyst support, and the insoluble catalyst support includes a fluoropolymer having a quaternary pyridine radical alone or in combination with an acetate radical grafted on the surface thereof. According to the disclosure, a fixed-bed bubble column reactor can be easily designed. In addition, a special device for catalyst separation is not required, and thus the device manufacturing cost can be saved, the operating cost can be reduced due to process simplification, and productivity can be greatly increased.

Abstract: The present invention provides a method for preparing dialkyl carbonate from urea or alkyl carbamate and alkyl alcohol using an ionic liquid comprising a cation, which produces a hydrogen ion, and a hydrophobic anion containing fluorine with high temperature stability in the presence of catalyst containing a metal oxide or hydrotalcite. Since the present invention can prepare dialkyl carbonate at a pressure lower than those of existing methods, it does not require an expensive pressure control device and peripheral devices for maintaining high pressure including the installation cost. It is also the method for preparing a dialkyl carbonate with high yield, thus improving economical efficiency. Moreover, the method of the present invention hardly produces any waste during the process and is thus an eco-friendly 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: The present invention provides a method for preparing dialkyl carbonate from urea or alkyl carbamate and alkyl alcohol using an ionic liquid comprising a cation, which produces a hydrogen ion, and a hydrophobic anion containing fluorine with high temperature stability in the presence of catalyst containing a metal oxide or hydrotalcite. Since the present invention can prepare dialkyl carbonate at a pressure lower than those of existing methods, it does not require an expensive pressure control device and peripheral devices for maintaining high pressure including the installation cost. It is also the method for preparing a dialkyl carbonate with high yield, thus improving economical efficiency. Moreover, the method of the present invention hardly produces any waste during the process and is thus an eco-friendly 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: The present invention provides a method for preparing dialkyl carbonate from urea or alkyl carbamate and alkyl alcohol using an ionic liquid comprising a cation, which produces a hydrogen ion, and a hydrophobic anion containing fluorine with high temperature stability in the presence of catalyst containing a metal oxide or hydrotalcite. Since the present invention can prepare dialkyl carbonate at a pressure lower than those of existing methods, it does not require an expensive pressure control device and peripheral devices for maintaining high pressure including the installation cost. It is also the method for preparing a dialkyl carbonate with high yield, thus improving economical efficiency. Moreover, the method of the present invention hardly produces any waste during the process and is thus an eco-friendly method.

Abstract: The present invention provides a method for preparing dialkyl carbonate from urea or alkyl carbamate and alkyl alcohol using an ionic liquid comprising a cation, which produces a hydrogen ion, and a hydrophobic anion containing fluorine with high temperature stability in the presence of catalyst containing a metal oxide or hydrotalcite. Since the present invention can prepare dialkyl carbonate at a pressure lower than those of existing methods, it does not require an expensive pressure control device and peripheral devices for maintaining high pressure including the installation cost. It is also the method for preparing a dialkyl carbonate with high yield, thus improving economical efficiency. Moreover, the method of the present invention hardly produces any waste during the process and is thus an eco-friendly method.

Abstract: The present invention relates to a method and an apparatus for concentrating an aqueous PTFE emulsion in which a raw, aqueous PTFE emulsion containing fluorinated surfactants is concentrated by an electrodialysis technique using at least one nonionic surfactant as an anti-flocculation agent and a volatile electrolyte such that the formation of floccules is prevented.