An enzyme-catalysed bleaching treatment to meet dissolving pulp characteristics for cellulose derivatives applications

作者：Quintana Elisabet^*; Valls Cristina; Vidal Teresa; Blanca Roncero M

来源：Bioresource Technology, 2013, 148: 1-8.

DOI：10.1016/j.biortech.2013.08.104

• Biobleaching
• Bioprocess
• Dissolving pulp
• Laccas
• Violuric acid

Bleached cellulose with good end-properties (similar to 90% ISO brightness and 62% cellulose preservation) was obtained by using a totally chlorine-free biobleaching process (TCF). Unbleached sulphite cellulose was treated with Trametes villosa laccase in combination with violuric acid. This enzymatic stage (L) was followed by a chelating stage (Q) and then by a hydrogen peroxide stage reinforced with pressurized oxygen (Po), resulting to an overall LQPo sequence. The use of violuric acid was dictated by the results of a preliminary study, where the bleaching efficiency of various natural (syringaldehyde and p-coumaric acid) and synthetic mediators (violuric acid and 1-hydroxybenzotriazole) were assessed. The outstanding results obtained with laccase-violuric acid system fulfil most of the characteristics of commercial dissolving pulp, totally acceptable for viscose manufacturing or CMC derivatives, with the added advantage that the enzymatic treatment saved 2 h of reaction time and about 70% of hydrogen peroxide consumption, relative to a conventional sequence (Po).

• 出版日期2013-11