Using Oxone and TAED activator in non-chlorine bleaching of soda bagasse pulp

Abstract

Bagasse fiber has been used in the production of bleached chemical pulp by the Pars Paper Company. In this company, a conventional three-stage sequence of hypochlorite, alkaline extraction and second hypochlorite (HEH) is applied in pulp bleaching. Pulp bleaching is one of the most important environmental pollutant stages in the pulp and paper industry. In this research, the bleaching of soda bagasse pulp by applying Oxone and TAED-activator in non-chlorine bleaching sequences has been investigated. The unbleached pulp, with kappa number of 20, 955 ml/g viscosity and 37 % brightness, was prepared from Pars Paper Company. Results indicated that, the TAED at the first and second stages were more effective than in the Oxone stages. Moreover, the sequences, which contained TAED- and Oxone-second-stage, could reach the minimum level of kappa (1.7), but the highest brightness (80 %) was attained by using only TAED with a comparatively high level of pulp viscosity (752).

The effect of treating pine regular kraft pulp with peracetic acid before O2-delignification on the consumption of ClO2 in D0ED1 bleaching

“…These percentage reductions in the kappa number of pulps samples correspond with the results seen in other studies. For example, Zeinaly et al (2019) pre-treated bagasse pulp with Paa [(obtained from a reaction of tetraacetylethylenediamine (TAED) with hydrogen peroxide)] and achieved an approx. 53% reduction of its kappa number, while Haque et al (2019) treated acacia pulp with performic acid, obtaining a 16 to 35% reduction of the index.…”

“…This is because, in addition to the decrease in the residual lignin content of the pulp, the amount of lignin moieties having a degradation activation energy equal or even greater than the degradation process of polysaccharides increases (Karhunen et al 1994;Akim et al 2001). To delignify kraft pulps of low residual lignin content more selectively in bleaching, it has been proposed to use two-stage oxygen delignification of the pulps (Saldivia 2002;Johnson et al 2009) or to pre-treat them with substances that activate the residual lignin moieties of reduced susceptibility for delignification (Fossum and Marklund 1988), such as: performic acid (Hauque et al 2019); peracetic acid (Paa) (Poukka et al 1999;Turner et al 2004;Chong et al 2015;Zeinaly et al 2019;Sharma et al 2020); persulfuric acid (Allison and McGrouter 1995;Jafari et al 2014;Rizaluddin et al 2015); perphosphoric acid (Springer 1997); and salts of these acids (Springer and McSweeny 1993;Allison and McGrouter 1997;Zeinaly et al 2019;Bourchard et al 2000).…”