Patent ID: 8535480

Claim:
A method for pulp manufacturing using cold caustic extraction for production of dissolving pulp, comprising: delignifying organic materials in a digester and treating a resulting brown stock to yield semi-purified pulp for use in the production of dissolving pulp; extracting the semi-purified pulp with a caustic solution during a cold caustic extraction process to yield a purified pulp and a solution containing hemicellulose; washing the purified pulp and collecting a spent washing liquid therefrom while separating the hemicellulose-containing solution from the purified pulp; combining the spent washing liquid and the hemicellulose-containing solution to form an alkaline filtrate; concentrating the alkaline filtrate to form a concentrated alkaline filtrate without purifying the hemicellulose-containing solution or alkaline filtrate to substantially remove the hemicellulose therein; and utilizing at least a portion of the concentrated alkaline filtrate in said digester in connection with production of dissolving pulp.