Date of Defense
Raja Aravamuthan, Paper and Printing Science and Engineering
John Cameron, Paper and Printing Science and Engineering
Thom Joyce, Paper and Printing Science and Engineering
Environmental concerns have applied pressure on the paper industry to change many erstwhile processes that have traditionally remained unchallenged. One process in particular is pulp bleaching. Elemental chlorine, while effective in bleaching pulp and low in capital cost, is a major environmental threat because of the toxic chlorinated compounds and other dioxins that are generated in mill effluents. With increasing technology and demand, there has been much research devoted to the development of alternate bleaching sequences, whether Elemental Chlorine Free (ECF), which can use Chlorine Dioxide (ClO2), or Totally Chlorine Free (TC). THe wide acceptance of these bleaching alternatives within the paper industry will face the challenge of a relative increase in capital expenditures, as well as how the resultant properties of the finished sheet compare with those from traditional bleaching methods. One such alternative that has been studied over the past ten years is the use of fungi-extracted enzymes as pre-bleaching agents to reduce subsequent bleaching chemical demand. This project examined the effects of pre-treating hardwood kraft pulp with enzymes representing both primary classes; hemicellulases (xylanase) and oxidases (laccase). Unlike previous research conducted and published in this area this project examined the effects of consecutive treatments with these enzymes on the same pulp sample. The goal of this project was to serve as a preliminary study to determine whether using two consecutive enzymatic pre-treatment stages featuring enzymes with different mechanisms of delignification demonstrated significant improvements in pulp bleaching and thus should be further researched.
Moore, Bryan R., "The Effect of Using Hemicellulase and Oxidase Successively as Pre-Bleaching Agents for Hardwood Kraft Pulp" (1999). Honors Theses. 505.
Honors Thesis-Open Access