Patent ID: 8007672

Claim:
A method for demineralizing condensate, comprising: passing condensate through a demineralization column comprising a bed of multiple layers of ion-exchange resin, wherein the multiple layers of the bed of ion-exchange resin consists of an uppermost first cation resin layer positioned in a first chamber, a first anion resin layer positioned under the uppermost first cation resin layer in a second chamber, a second cation resin layer positioned under the first anion resin layer in a third chamber, and a second anion resin layer positioned under the second cation resin layer positioned in a fourth chamber, the demineralization column has a partition present between each of the chambers such that the resin layers do not mix with one another, and each of the uppermost first cation resin layer and second cation resin layer comprises a uniform particle size strong acid gel-type cation resin having a degree of crosslinking from 12% to 15%, an average particle size of from 500 to 800 μm and a uniformity coefficient of less than or equal to 1.2, and at least 95% of resin particles have a particle size within ±100 μm of the average particle size; transferring each of the cation resins from the first and second cation resin layers in the first and third chambers of the demineralization column separately using water and air to first and second chambers, respectively, of a cation resin regeneration column; transferring each of anion resins from the first and second anion resin layers in the second and fourth chambers of the demineralization column separately using water and air to first and second chambers, respectively, of an anion resin regeneration column; subjecting each of the cation resins of the first and second cation resin layers simultaneously to a chemical flowthrough regeneration and washing separately in first and second chambers, respectively, of said cation resin regeneration column such that the cation resin from the uppermost first cation resin layer and the cation resin from the second cation resin layer are regenerated without being mixed with each other; and subjecting each of the anion resins of the first and second anion resin layers simultaneously to a chemical flowthrough regeneration and washing separately in first and second chambers, respectively, of said anion regeneration column such that the anion resin from the first anion resin layer and the anion resin from the second anion resin layer are regenerated without being mixed with each other.