US 6,364,999 B1 · Process for producing a wood pulp having reduced pitch content and process and reduced VOC-emissions

Abstract

Paper and absorbent products having reduced pitch content and enhanced properties, including increased tensile index, tear index, burst index, Scott Bond, smoothness, and stiffness. Further, pulps of the invention, although having slightly reduced brightness, are more responsive to bleach chemicals thereby permitting the use of less chemicals to achieve a specific brightness. The products are produced by a process that includes extracting wood particulates with a solvent for naturally-occurring volatile organic compounds and pitch. The extracted wood particulates are then pulped and formed into paper and absorbent products with enhanced properties. Due to the extraction of volatile organic compounds, the pulping and paperforming stages of the process are substantially free of emissions of volatile organic compounds that occur naturally in wood. Moreover, the extraction of pitch reduces or eliminates pitch fouling of equipment and permits the production of paper products of enhanced qualities.

Claims15

Dependent claims

A reduced VOC-emissions process for producing a wood pulp comprised of wood fibers from wood particulates comprising wood fibers, pitch, and volatile organic compounds, the process comprising:

(a) contacting wood particulates, containing naturally-occurring pitch and naturally-occurring volatile organic compounds, with an extraction solvent for the pitch and the volatile organic compounds to extract at least a portion of the pitch and a portion of the volatile organic compounds from the wood particulate into the solvent, under a pressure less than 50 psi without significant dissolution of lignin and cellulosic components of the wood, to produce extracted particulates, the solvent of the solvent extraction process being recovered and recycled for reuse, said solvent being selected from the group consisting of methanol, ethanol and acetone;
(b) mechanically fiberizing the solvent-extracted wood particulates;
and
(c) producing a wood pulp comprising wood fibers and lignin wherein the fiberizing and the producing steps have significantly reduced emissions of naturally-occurring volatile organic compounds, as compared to emissions from fiberizing and producing a wood pulp from wood particulates containing naturally-occurring levels of volatile organic compounds.

1 more element

Dependencies are inferred from the claim text.

Process for producing a wood pulp having reduced pitch content and process and reduced VOC-emissions

Life of this patent

Process for producing a wood pulp having reduced pitch content and process and reduced VOC-emissions

Life of this patent

Abstract

Claims15