Use of a nitrogen-centered peroxide activator to increase the chromophore removal potential of peroxide-lignin model compound study

• Published in: Journal of wood chemistry and technology Vol. 26; no. 2; pp. 165 - 174
• Main Authors: Hu, Q.Y, Daneault, C, Robert, S
• Format: Journal Article
• Language: English
• Published: Colchester Taylor & Francis Group 01.01.2006; Taylor & Francis
• Subjects: Acetovanillone; activators; Applied sciences; Exact sciences and technology; hydrogen peroxide; lignin; lignin model; model compounds; oxidation; Paper, paperboard, non wovens; peroxyacetic acid; Polymer industry, paints, wood; Pulp manufacturing; TAED; tetraacetylethylenediamine; Wood. Paper. Non wovens; tetraacetylethylenediamine; activators; Acetovanillone; Paper pulp; hydrogen peroxide; lignin model; TAED; peroxyacetic acid
• ISSN: 0277-3813; 1532-2319
• DOI: 10.1080/02773810600704335

The kinetics of reaction of a lignin model compound, acetovanillone (4'-hydroxy-3'-methoxyacetophenone), in tetraacetylethylenediamine (TAED)/H2O2 and peroxide-alone systems were investigated. The oxidation of acetovanillone followed first-order kinetics in both systems. In the TAED-peroxide system, the first-order rate constant, k, was 0.34 min-1 with a half-life, t1/2, of 2 min, compared to k of 0.0035 min-1 and t1/2 of 220 min in the peroxide-alone system. Thus, TAED/H2O2 oxidized acetovanillone about one hundred times faster than peroxide alone. The results of the study explain why, when using TAED/H2O2 to bleach TMP softwood pulp, the initial pH should be about 11 for increased production of peroxyacetic acid, and the final pH should be about 7 to minimize decomposition and increase bleaching efficiency and reactivity.