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.

Date of Patent:
Aug. 04, 1998

Filed:

Jun. 07, 1995
Applicant:
Inventors:

Richard C Agar, Springdale, OH (US);

Jairo H Lora, Media, PA (US);

Malcolm Cronlund, Chester Springs, PA (US);

Chih Fae Wu, West Chester, PA (US);

Gopal C Goyal, Collegeville, PA (US);

Stephen R Winner, Boothwyn, PA (US);

Mikhail N Raskin, King of Prussia, PA (US);

Raphael Katzen, Cincinnati, OH (US);

Ron LeBlanc, via Dhahran, SA;

Assignee:

Other;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ; D21C / ;
U.S. Cl.
CPC ...
162 16 ; 162 37 ; 162 39 ; 162 77 ; 549490 ;
Abstract

This invention provides for the recovery of lignin and other by-products from the pulping of fibrous plant material. In accordance with this invention, solvents and filtrates are recovered and recycled for reuse. This results in significant solvent and energy savings. Filtrates from the bleaching and delignification of the pulp are recycled for reuse in pulping, separation, and recovery of lignin and other by-products which results in significant energy savings and mitigation if not the elimination of pollution typically associated with bleaching. This invention also relates to products derived from the process and apparatus for carrying out the process. Lignins of various molecular weights and by-products of the pulping process are also recovered. The lignins are precipitated in high yields and at a high rate from a black liquor produced by pulping wood at high temperature and pressures. As a by-product of this process a purified furfural product is recovered. This furfural may be recycled for use in the recovery of the low molecular weight lignin of this process.


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