The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 28, 1978
Filed:
Jan. 03, 1978
Applicant:
Inventors:
John S Fujii, Vancouver, WA (US);
William G Whalley, Vancouver, WA (US);
Fred L Schmidt, Camas, WA (US);
Assignee:
Crown Zellerbach Corporation, San Francisco, CA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ;
U.S. Cl.
CPC ...
162 40 ; 162 38 ; 162 72 ; 162 90 ;
Abstract
By pretreating lignocellulose with an alkaline pretreatment liquor containing anthraquinone or a related compound, prior to alkaline digestion, a higher yield of pulp having a lower lignin content can be produced using less alkali. The pretreatment step is carried out under conditions that ensure survival of at least 50% of the anthraquinone or related compound in the pretreatment liquor, which is separated from the pretreated lignocellulose and reused to pretreat other lignocellulose.