Method for Organic-Solvent Removal
AssigneeAsahi Kasei Kabushiki Kaisha
InventorFumiyoshi Inoue
Life of this patent
Estimating the term…
Abstract
A method for organic-solvent removal which comprises bringing a raw solution comprising a solute, an organic solvent, and water into contact with an absorbing liquid, with a hydrophobic porous membrane interposed therebetween, to move the organic solvent contained in the raw solution to the absorbing liquid, wherein the absorbing liquid may or may not contain an organic solvent of the same kind as the organic solvent contained in the raw solution, the raw solution at 25° C. has a vapor pressure of the organic solvent of 0.60 kPa or greater, the raw solution being in contact with the hydrophobic porous membrane has a temperature of 40° C. or lower, the absorbing liquid being in contact with the hydrophobic porous membrane has a temperature of 5° C. or higher.
Claims15
An organic solvent removal method in which a feed solution comprising a solute, an organic solvent and water is contacted with an absorbing solution through a hydrophobic porous membrane, causing the organic solvent in the feed solution to move into the absorbing solution, wherein:
- the absorbing solution may contain or not contain an organic solvent of the same type as the organic solvent in the feed solution,
- the vapor pressure of the organic solvent in the feed solution at 25° C. is 0.60 kPa or higher,
- the temperature of the feed solution that contacts with the hydrophobic porous membrane is 40° C. or lower,
- the temperature of the absorbing solution that contacts with the hydrophobic porous membrane is 5° C. or higher,
- the temperature difference between the feed solution and the absorbing solution is 10° C. or less, and
- the vapor pressure of the organic solvent in the feed solution that contacts with the hydrophobic porous membrane is higher than the vapor pressure of the organic solvent in the absorbing solution that contacts with the hydrophobic porous membrane.
An organic solvent removal device comprising:
- a membrane module for membrane distillation having a hydrophobic porous membrane, a space A for contact of the feed solution with one side of the hydrophobic porous membrane, and a space B for contact of the absorbing solution with the other side of the hydrophobic porous membrane,
- a feed solution pump for delivery of the feed solution to the space A, and
- an absorbing solution pump for delivery of the absorbing solution to the space B,
- wherein the organic solvent removal device may have or not have a heat exchanger in the tubing for delivery of the feed solution, and
- when the organic solvent removal device has a heat exchanger, the value of the effective area of the heat exchanger divided by the effective membrane area of the membrane module for membrane distillation is 1.5 or lower.
(canceled)
A concentration method for a feed solution which comprises a solute, an organic solvent and water, the method comprising:
- organic solvent removal in which the feed solution and an absorbing solution are contacted through a hydrophobic porous membrane, causing the organic solvent in the feed solution to move into the absorbing solution, and
- water removal in which the feed solution and a draw solution are contacted through a forward osmosis membrane, causing the water in the feed solution to move into the draw solution, wherein in the organic solvent removal,
- the absorbing solution may contain or not contain an organic solvent of the same type as the organic solvent in the feed solution,
- the vapor pressure of the organic solvent in the feed solution at 25° C. is 0.60 kPa or higher,
- the temperature of the feed solution that contacts with the hydrophobic porous membrane is 40° C. or lower,
- the temperature of the absorbing solution that contacts with the hydrophobic porous membrane is 5° C. or higher,
- the temperature difference between the feed solution and the absorbing solution is 10° C. or less, and
- the vapor pressure of the organic solvent in the feed solution that contacts with the hydrophobic porous membrane is higher than the vapor pressure of the organic solvent in the absorbing solution that contacts with the hydrophobic porous membrane.
Dependencies are inferred from the claim text.