Chih Fae Wu

US Patent:

47645962, Aug 16, 1988

Filed:

Dec 11, 1986

Appl. No.:

6/940460

Inventors:

Jairo H. Lora - Media PA
Raphael Katzen - Cincinnati OH
Malcolm Cronlund - Chester Springs PA
Chih F. Wu - King of Prussia PA

Assignee:

Repap Technologies Inc. - Valley Forge PA

International Classification:

C07G 100
D21C 320

US Classification:

530507

Abstract:

Lignin is precipitated in high yields and at high rates from a black liquor produced by pulping wood at high temperatures and pressures with an aqueous lower aliphatic alcohol solvent. The lignin is precipitated by diluting the black liquor with water and an acid to form a solution with a pH of less than about 3, an alcohol content of less than about 30% by volume and a temperature of less than about 75. degree. C. The precipitated lignin, when subsequently dried, is in the form of a powder which requires little or no crushing to convert it into a fine uniform size suitable for use without further significant processing.

US Patent:

57888124, Aug 4, 1998

Filed:

Jun 7, 1995

Appl. No.:

8/488306

Inventors:

Richard C. Agar - Springdale OH
Jairo H. Lora - Media PA
Malcolm Cronlund - Chester Springs PA
Chih Fae Wu - West Chester PA
Gopal C. Goyal - Collegeville PA
Stephen R. Winner - Boothwyn PA
Mikhail N. Raskin - King of Prussia PA
Raphael Katzen - Cincinnati OH
Ron LeBlanc - via Dhahran, SA

International Classification:

D21C 320
D21C 1100

US Classification:

162 16

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.