- Collection:
- Atlanta University and Clark Atlanta University Theses and Dissertations
- Title:
- The chemistry of hexenuronic acid in pulping and bleaching hexenuronic acid generation and its selective hydrolysis from kraft pulp, 1998
- Creator:
- Hagos, Asmerom M.
- Date of Original:
- 1998-07-01
- Subject:
- Degrees, Academic
Dissertations, Academic - Location:
- United States, Georgia, Fulton County, Atlanta, 33.749, -84.38798
- Medium:
- theses
- Type:
- Text
- Format:
- application/pdf
- Description:
- Currently, the pulping and bleaching industries have developed significant interest in the minimization of chemical bleaching costs. Our interest on this project stems from this reality. During the kraft delignification process 4-O-methyl-D-glucuronic acid-D-xylan forms hexenuronic acid by base catalyzed P-elimination of the methoxy group. Hexenuronic acids consume bleaching agents and cause an apparent increase of the kappa number of the pulp. This research was directed at developing a more flexible method of removing hexenuronic acids without affecting the pulp considerably. This method is based on mild acid hydrolysis which selectively removes hexenuronic acids from kraft pulps. The effect of temperature on the formation of hexenuronic acids was also studied. Moreover, oxygen delignification of kraft pulp is observed to have no effect on the amount of hexenuronic acids.
- External Identifiers:
- Metadata URL:
- http://hdl.handle.net/20.500.12322/cau.td:1998_hagos_asmerom_m.pdf
- Rights Holder:
- Clark Atlanta University
- Holding Institution:
- Atlanta University Center Robert W. Woodruff Library
- Rights:
-
