MECHANISMS OF TMP PEROXIDE BLEACHING USING MG-BASED ALKALIS
The driving force for pulp and paper industry is to develop new technologies so as to have minimum impact to environment. As a solution, the use of sodium hydroxide during peroxide bleaching of thermo- mechanical pulp was successfully partially substituted by magnesium hydroxide or magnesium carbonate, resulting in an equivalent pulp brightness. Looking at brightening development, thioacidolysis showed that Mg-based processes eliminated less coniferaldehydes than NaOH-based bleaching. Moreover, 19F NMR analysis showed slighty more residual quinone in lignin isolated from NaOH-based bleached pulp than lignin extracted after Mg-based bleaching. However, the brightness reversion of Mg-based bleached paper decreased by about 2 ISO points during photoageing under sunlight. X-ray photoelectron spectroscopy supported the conclusion that compared to the conventional process, Mg-based bleaching caused less re-deposition of lignin and extractives onto the fibre surface, resulting in less light-induced yellowing.
Bleaching hydrogen peroxide H2O2 19F RMN magnesium carbonate magnesium hydroxide MgCO3 Mg(OH)2 mechanism sodium hydroxide thermomechanical pulp TMP thioacidolysis X-ray photoelectron spectroscopy XPS
Liliane Savoye Valérie Meyer Michel Petit-Conil
Centre Technique du Papier BP 251, 38044 Grenoble Cedex 9, France
国际会议
International Mechanical Pulping Conference 2011(2011国际机械浆学术会议)
西安
英文
299-305
2011-06-26（万方平台首次上网日期，不代表论文的发表时间）