×

Lignin removal method using ozone and acetic acid

  • US 5,074,960 A
  • Filed: 10/31/1990
  • Issued: 12/24/1991
  • Est. Priority Date: 01/25/1988
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method of bleaching a cellulosic pulp material containing a substantial amount of lignin for removal of said lignin from said cellulosic pulp material consisting essentially of the steps of:

  • contacting said cellulose pulp material with a gaseous medium containing ozone in the presence of a liquid processing agent comprising an aqueous acetic acid solution having an acid content of at least 50% by weight, and causing an oxidative conversion of said lignin so as to increase the solubility of said lignin in said liquid processing agent and to improve said removal of said lignin from said cellulosic pulp material.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×