Hydrogen Peroxide Recovery with Hydrophobic Membrane

Abstract

An apparatus and process are presented that provide for the separation of hydrogen peroxide from a solution having an acid and hydrogen peroxide.

1 . A method of generating hydrogen peroxide comprising:
 oxidizing a sulfate to generate a persulfate in an electrolyzer generating a persulfate liquid stream;   hydrolyzing the persulfate stream with water to generate a hydrolyzed solution having hydrogen peroxide and a sulfate compound;   separating the hydrogen peroxide and sulfate solution to a separation unit to form a first stream comprising hydrogen peroxide and a second stream comprising sulfate, wherein the separation unit comprises: a hydrophobic membrane permeable to the vapor phase and impermeable to the liquid phase; and   recycling the second stream to the electrolyzer.   
     
     
         2 . The method of  claim 1  further comprising condensing the vapor phase to generate a substantially sulfate free hydrogen peroxide solution. 
     
     
         3 . The method of  claim 1  wherein separating the liquid and vapor phases comprises passing the vapor phase to a vapor liquid separator comprised of hollow fibers permeable to the gas phase disposed within a shell and impermeable to entrained liquid droplets, wherein the vapor phase is admitted to the shell side of the fibers within the separator, and the vapor phase diffuses through the fiber walls to the lumen side and the vapor phase is carried through the hollow fibers. 
     
     
         4 . The method of  claim 1  wherein the hydrophobic membrane is permeable to hydrogen peroxide vapor and impermeable to aqueous droplets. 
     
     
         5 . The method of  claim 1  further comprising the addition of water to the second stream to reduce the viscosity of the liquid phase. 
     
     
         6 . The method of  claim 1  wherein the separation step comprises passing the hydrolyzed solution to a separator comprised of hollow fibers permeable to hydrogen peroxide and disposed within a shell, wherein the solution is passed to the lumen side of the hollow fibers and the hydrogen peroxide permeates the fiber walls to the shell side of the fiber walls. 
     
     
         7 . The method of  claim 1  wherein the separation step comprises passing the liquid phase to the shell side of vapor liquid separator comprising hollow fibers, and passing the vapor to the lumen side of fibers in the separator. 
     
     
         8 . The method of  claim 1  wherein the separation step comprises passing the vapor phase to the shell side of vapor liquid separator comprising hollow fibers, and passing the liquid to the lumen side of fibers in the separator. 
     
     
         9 . The method of  claim 1  wherein the evaporator is a gas stripping unit.