초록 ▼

Recovery of ethylene glycol from dilute aqueous solutions is accomplished by passing the solution over the surface of a porous hydrophobic membrane capable of passing water vapor but not liquid water. The pressure and temperature provide a positive driving force for the movement of water vapor throu

Recovery of ethylene glycol from dilute aqueous solutions is accomplished by passing the solution over the surface of a porous hydrophobic membrane capable of passing water vapor but not liquid water. The pressure and temperature provide a positive driving force for the movement of water vapor through the membrane to the opposite face where it is removed by condensation or a stream of gas or liquid. Preliminary concentration of the aqueous solutions may be provided by use of reverse osmosis membrane. The method is useful in the reclamation of spent deicing fluid.

대표청구항 ▼

A method of concentrating spent deicing fluid wherein said fluid is selected from the group consisting of ethylene glycol and propylene glycol in aqueous solutions by removing water therefrom consisting essentially of: (a) passing said aqueous glycol solution over one face of a hydrophobic porous me

A method of concentrating spent deicing fluid wherein said fluid is selected from the group consisting of ethylene glycol and propylene glycol in aqueous solutions by removing water therefrom consisting essentially of: (a) passing said aqueous glycol solution over one face of a hydrophobic porous membrane having 0.01 to 2.0 m40°C. and 80°C. and above the temperature on the opposite face of said membrane between about 5°C. and 40°C., whereby water vapor from said solution passes through the pores of said membrane to said opposite membrane face while rejecting liquid water and glycol and said aqueous glycol solution is concentrated by removing said water vapor; (b) removing said water vapor of (a) passed through said membrane; and (c) recovering the concentrated aqueous glycol solution. An apparatus for the concentration of spent deicing fluid wherein said fluid is selected from the group consisting of ethylene glycol and propylene glycol in an aqueous solution by removing water therefrom consisting essentially of: (a) an evaporative membrane means in contact with said glycol solution for removing water as vapor from said solution wherein said membrane means has pores of about 0.01 to 2.0 m40°C. and 80°C. on said first face of said membrane means and between about 5°C. and 40°C. on the opposite face of said membrane to establish a vapor pressure differential across said membrane means; (c) means for removing said water vapor of (a) pass through said membrane; and (d) means for recovering the concentrated aqueous glycol solution.