Patent ID: 7699958
Filing Date: 2010-04-20
Classification: D21C

Abstract:
1. A method for separating carbohydrates from pulping liquors, comprising the steps of: providing a wood pulping or wood or biomass hydrolysis liquor having lignin therein; mixing said liquor with an acid or a gas which forms an acid upon contact with water to initiate precipitation of carbohydrate to begin formation of a precipitate; and, during said precipitation, adding at least one long chain carboxylated carbohydrate and at least one cationic polymer, wherein said precipitate aggregates into larger precipitate structures, and selectively removing carbohydrate gel precipitates from said larger precipitate structures; wherein said mixing step comprises adding said acid or said gas which forms an acid upon contact with water to adjust the pH of said liquor to an end range from 9.5 to 10.0.