Processes for deionization and demineralization of fluids

A process for deionization and demineralization of a fluid containing ions comprising:

• (a) Loading an amine or ammonia buffer onto a first weakly acidic cation exchange resin to occupy cation exchange sites and to form a first bed comprising a first amine-buffered resin;
• (b) Passing said fluid containing ions through said first bed comprising said first amine-buffered resin and exchanging cations of said fluid for amine cations of said first amine-buffered resin to form a first effluent comprising an anion-buffer salt complex;
• (c) Passing said anion-buffer salt complex through a first weakly basic anion exchange resin where an anion portion of said anion-buffer salt complex is split from said anion-buffer salt complex by adsorption of said anion portion onto said weakly basic anion exchange resin to form a second effluent comprising buffer in free hydrated base form;
• (d) Passing said buffer in free hydrated base form to a second weakly acidic cation exchange resin where said buffer loads onto said second weakly acidic cation exchange resin as in step (a) and repeating the process of steps (b)-(d);
• (e) Regenerating said first weakly acidic cation exchange resin with an organic acid to reestablish said first weakly acidic cation exchange resin to hydrogen form and to form a spent organic acid regenerant comprising a mixture of cation salts of the organic acid regenerant and free organic acid regenerant;
• (f) Regenerating said first weakly basic anion exchange resin with an organic base to reestablish said first weakly basic anion exchange resin to free hydrated base form and to form a spent organic base regenerant comprising a mixture of anion salts of said organic base regenerant and free organic base regenerant;
• (g) Distilling said spent organic base regenerant to remove free organic base regenerant for reuse in step (f);
• (h) Combining said anion salts of said organic base regenerant with said spent organic acid regenerant to form a regenerant product solution having an acidic pH comprising an organic acid, an organic acid/organic base complex and neutral inorganic salts;
• (i) Subjecting said regenerant product solution to evaporation so that water is condensed and collected leaving a concentrated regenerant product solution comprising said organic acid regenerant, residual organic acid/organic base complex and neutral inorganic salts;
• (j) Combining said concentrated regenerant product solution with an alcohol causing said neutral inorganic salts to precipitate;
• (k) Filtering to remove said neutral inorganic salts precipitated in step (j) and distilling filtrate to remove said alcohol;
• (l) Passing alcohol-free filtrate formed in step (k) through a chromatographic column to separate free organic acid from said organic acid/organic base complex;
• (m) Passing said organic acid/organic base complex collected in step (1) to a dissociation-distillation column where dissociation of said organic acid/organic base complex yields free organic base and water, which are separated from said organic acid/organic base complex, and collected and reused in step (g);
• and
• (n) Returning separated free organic acid from step (1), which contains up to 5% organic acid/organic base complex to step (e).