Method for preparing an ion exchange media
This invention presents an ion exchange media including a plurality of cation exchange zones and anion exchange zones in flow paths that are contained in a substantially nonporous resin transport framework. During electrodeionization and other potential applications the ion exchange media of the invention prevents unfavorable water splitting at resin-membrane interfaces and encourages water splitting at resin-resin interfaces where the water splitting may be constructively used to regenerate the resin.
1. A method for constructing an ion exchange media, comprising the steps of
1) preparing a nonporous cation resin side, wherein said nonporous cation resin side is formed by the steps of
a) drying a nonporous cation resin,
b) grinding said cation resin,
c) optionally sieving said cation resin,
d) impregnating said cation resin into a binding agent to form a cation resin mixture,
e) partially drying said cation resin mixture,
f) shaping said cation resin mixture, and
g) drying said cation resin mixture;
2) preparing a nonporous anion resin side, wherein said nonporous anion resin side is formed by the steps of
a) drying said a nonporous anion resin,
b) grinding said anion resin,
c) optionally sieving said anion resin,
d) impregnating said anion resin into a binding agent to form an anion resin mixture,
e) partially drying said anion resin mixture,
f) shaping said anion resin mixture, and
g) drying said anion resin mixture;
3) combining said anion resin side and said cation resin side such that they meet at an interface to form a nonporous resin transport framework, said transport framework including at least one void extending longitudinally through said transport framework at the interface and along the length of the transport framework; and
4) filling said void with a plurality of alternating layers of a porous second cation resin and a porous second anion resin to form at least one flow path.
2. The method of claim 1 , including before the step of filling said void the additional step of binding each of said anion resin and said cation resin into a plurality of blocks having shapes corresponding to the cross-section of said void.
3. The method of claim 1 , wherein the respective binding agents may be the same binding agent, different binding agent, or a mixture of the same binding agent and different binding agent.
4. The method of claim 2 , wherein the resin comprising the resin transport framework and the resin comprising the blocks may be regenerated resin, exhausted resin, or a combination of the two.
5. The method of claim 2 , wherein said resin transport framework comprises a first binding agent with a first porosity, and wherein said blocks comprise a binding agent with a second porosity, and wherein said second porosity is greater than said first porosity.
6. The method of claim 2 , wherein the average particle size of the resin comprising the resin transport framework is smaller than the average particle size of the resin comprising the blocks.
7. The method of claim 2 , wherein said resin transport framework is comprised of a binding agent and said flow path is comprised of a binding agent, and wherein the concentration of said binding agent in said resin transport framework is greater than the concentration of said binding agent in said flow path.