Pretreatment of wood particulates for removal of wood extractives

Patent 5698667 Issued on December 16, 1997. Estimated Expiration Date:

December 27, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

1919623

2022654

2106797

2273039

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3635789

Composition for deinking waste paper
Patent #: 3963560
Issued on: 06/15/1976
Inventor: Mestetsky , et al.

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Inventors

Assignee

Application

No. 579475 filed on 12/27/1995

US Classes:

530/202, Cut wood starting material used in process, or product thereof (e.g., using pine stumps, chips, bark, etc., as starting material)162/74Chlorine containing

Examiners

Primary: Nutter, Nathan M.

Attorney, Agent or Firm

Christensen O'Connor Johnson & Kindness PLLC

Foreign Patent References

60-163959 JP. 08/23/1985

International Classes

C09F 001/02
D21C 003/20

Abstract

A process for extracting volatile organic compounds and pitch from wood particulates, thereby virtually eliminating the emission of volatile organic compounds into the atmosphere during the processing of wood particulates into commercially useful products, such as oriented strandboard, particle board, chipboard veneers, and pulp and paper products. The removal of pitch permits the production of pulps of higher brightness, requiring less chemical bleaching agents. Moreover, removal of pitch eliminates pitch scale formation in pulp mills and on pulp and paper machines with resultant improved efficiencies and reduced use of pitch treatment chemicals. In the extraction process, a solvent or blend of solvents, leach wood extractives, including volatile organic compounds and pitch, from the wood particulates to produce a miscella. The miscella is separated from the leached wood particulates and solvent contained in the miscella is recovered and recycled for reuse. The wood extractives of the miscella may be sold as chemical feedstocks or used as a fuel. Any volatile organic compounds released as vapors in wood processing operations prior to the extraction step are collected, absorbed onto activated carbon particulates, and recovered for sale or combustion.

Other References

T. Chen et al., "Using solid-phase extraction to assess why aspen causes more pitch problems than softwoods in kraft pulping", Wood and Pulping Chemistry, vol. 78, No. 10, Oct. 1995, Tappi Journal, pp. 143-149
J. Brandal et al., "The Influence of Extractives in Groundwood Pulp on Fibre Bonding", Pulp and Paper Magazine of Canada, Oct., 1966, pp. T-431-T-435
"New Pulps `Explode` onto Scene", Pulp & Paper Canada, Jun. 1987, p. 4