摘要:
The present invention is directed to a process for producing a high molecular weight condensation polymer by removing unwanted by-product(s) from a polycondensation equilibrium reaction mixture using a centrifugal force device equipped with a vacuum.
摘要:
A process of preparing alkylene oxides comprises steps of: (1) optionally contacting metal hydroxide or oxide with chlorine to form a metal hypochlorite solution; (2) contacting chlorine with a solution of a metal hypochlorite at a temperature below 60 °C, and a pH of less than 5.5, with sufficient micromixing to achieve a product hypochlorous acid in a yield of at least 80 mole percent based on hypochlorite; (3) separating at least a portion of the hypochlorous acid from an aqueous metal chloride solution thereof, hereinafter referred to as chloride brine, wherein the solution is sprayed as droplets having a volume median diameter of less than 500 micrometers into a vapor stream such that at least 30 mole percent of the hypochlorous acid is desorbed from a liquid phase into a vapor phase where hypochlorous acid and dichlorine monoxide are in equilibrium; (4) distilling the remaining liquid phase to obtain additional hypochlorous acid and dichlorine monoxide vapor; (5) absorbing the hypochlorous acid and dichlorine monoxide in low-chlorides water to produce a low-chlorides aqueous hypochlorous acid solution; (6) contacting the low-chlorides aqueous hypochlorous acid solution with an olefin in a continuous process using a continuous stirred tank reactor to maintain a uniform steady-state HOCl concentration in the reactor of 0.2 weight percent or less to form a corresponding olefin chlorohydrin; (7) optionally contacting the olefin chlorohydrin with a base to form a corresponding alkylene oxide and a salt solution; and (8) optionally separating the alkylene oxide from the salt solution; (9) optionally removing chlorates from the chloride brine from at least one of Steps 3 or 4 by contacting the chlorates with acid to convert the chlorates to chlorine; and (10) optionally recycling the chlorine to at least one of Steps 1 or 4. The process yields particularly high yields of the alkylene oxide without substantial production of by-products.
摘要:
This invention is a method for forming hypohalous acid in a mass transfer device. The method comprises: (1) feeding into the device a stream of caustic solution comprising at least one alkali or alkaline earth metal of a hydroxide, oxide, hypohalite, bicarbonate, or carbonate; (2) feeding a stream comprising halogen gas into the device; (3) reacting at least some of the halogen gas with the caustic solution to form a solution containing hypohalous acid; (4) desorbing the hypohalous acid from the solution and into the stream of halogen gas; and (5) removing the stream of halogen gas from the device. In this method, the mass transfer device comprises a porous rotor which is permeable to the streams, and is rotated about an axis such that the streams flow through the rotor and the stream of caustic solution flows radially outward from the axis.
摘要:
A process of preparing alkylene oxides comprises steps of: (1) optionally contacting metal hydroxide or oxide with chlorine to form a metal hypochlorite solution; (2) contacting chlorine with a solution of a metal hypochlorite at a temperature below 60 °C, and a pH of less than 5.5, with sufficient micromixing to achieve a product hypochlorous acid in a yield of at least 80 mole percent based on hypochlorite; (3) separating at least a portion of the hypochlorous acid from an aqueous metal chloride solution thereof, hereinafter referred to as chloride brine, wherein the solution is sprayed as droplets having a volume median diameter of less than 500 micrometers into a vapor stream such that at least 30 mole percent of the hypochlorous acid is desorbed from a liquid phase into a vapor phase where hypochlorous acid and dichlorine monoxide are in equilibrium; (4) distilling the remaining liquid phase to obtain additional hypochlorous acid and dichlorine monoxide vapor; (5) absorbing the hypochlorous acid and dichlorine monoxide in low-chlorides water to produce a low-chlorides aqueous hypochlorous acid solution; (6) contacting the low-chlorides aqueous hypochlorous acid solution with an olefin in a continuous process using a continuous stirred tank reactor to maintain a uniform steady-state HOCl concentration in the reactor of 0.2 weight percent or less to form a corresponding olefin chlorohydrin; (7) optionally contacting the olefin chlorohydrin with a base to form a corresponding alkylene oxide and a salt solution; and (8) optionally separating the alkylene oxide from the salt solution; (9) optionally removing chlorates from the chloride brine from at least one of Steps 3 or 4 by contacting the chlorates with acid to convert the chlorates to chlorine; and (10) optionally recycling the chlorine to at least one of Steps 1 or 4. The process yields particularly high yields of the alkylene oxide without substantial production of by-products.