Patent ID: 8273181

Claim:
A process for obtaining a product stream comprising one or more sulfate salts of monovalent cations selected from the group consisting of potassium, sodium, ammonium, and combinations thereof, from a sugar stream resulting from the hydrolysis of a lignocellulosic feedstock, comprising the steps of: (i) feeding the sugar stream comprising calcium sulfate and one or more sulfate salts of the monovalent cations to a resin bed that binds calcium to remove calcium, thereby producing a sugar stream containing substantially no calcium ions, and obtaining a salt stream comprising a soluble calcium salt by regenerating the resin bed with a regenerant to produce a regenerated stream comprising the soluble calcium salt; (ii) obtaining a feed stream that is either (a) a clarified salt stream derived from the salt stream of step (i) after precipitation and removal of calcium therefrom or (b) the sugar stream containing substantially no calcium ions that is produced in step (i) and wherein said feed stream contains said one or more salts of the monovalent cations; (iii) introducing the feed stream obtained in step (ii) to an ion exchange resin bed; and (iv) regenerating the ion exchange resin bed of step (iii) with sulfuric acid to produce a product stream comprising one or more sulfate salts of monovalent cations selected from the group consisting of potassium, sodium, ammonium, and combinations thereof.