Enzyme cocktail: An opportunity for greener agro-pulp biobleaching in paper industry

Abstract

An enzyme cocktail (xylanase-15U, pectinase-2U, α-amylase-2.5U, protease-2U and lipase- 1.8U) from Bacillus halodurans was applied for the biobleaching of unbleached and ODL (oxygen delignification) agro based pulp in the R&D set up of Shreyans Paper Mills Ludhiana, India, upscaling from 5 g (at lab scale) to 100 g odp (oven dried pulp). Enzyme pre-treatment was carried out at temperature and pH optima of 65 °C and 9–9.5 for 90 min followed by reduced chemical treatment. In case of unbleached agro pulp, as compared to the total chemical bleaching in mill, enzyme cocktail pre-treatment reduced the chemical usage by 50% without compromising brightness and rather with increased tensile strength (23.55%), burst factor (20.3%) and tear factor (3.17%) and reduced kappa number (19.5%). In case of ODL pulp, enzyme cocktail pre-treatment reduced the chemical usage by 40%, yet increasing brightness (2.24%), tensile strength (20.96%), burst factor (5.1%) and tear factor (8.2%) with reduction in kappa number (4.54%). The enzyme cocktail thus can make the paper manufacturing process greener, safer, economical and eco-friendly and may replace big budget ODL technologies.