Approaches for converting sugarcane trash, a promising agro residue, into pulp and paper using soda pulping and elemental chlorine-free bleaching.

Abstract Industrialization and urbanization are the key drivers to threaten the environmental quality and natural resources. Traditionally, pulp and paper industry has been highly reliant on forest based resources for its escalation. Shortage of forest based raw materials, strict environmental regulations and policies have compelled the industry to seek for alternate raw materials for its production. Mills are now focusing on exploring the potential of different agro wastes such as cereal straws and bagasse etc. In present research, sugarcane trash, one of the most abundant agro residues in India, was investigated for its capability in pulping and bleaching. Chemical characterization of sugarcane trash showed that it contains 40.4% cellulose, 33.2% hemicelluloses, 17.4% lignin and 6.45% ash content with 2.76% silica. To cook sugarcane trash with soda pulping method, 14% alkali charge, 15 min time and 162 °C temperature was found to be optimum and pulp of kappa no. 19.8 was prepared that exhibited good strength properties. Bleaching of pulp was carried out using elemental chlorine (Cl 2), hypochlorite and chlorine dioxide (ClO 2) based sequences. Replacement of Cl 2 with ClO 2 has significant impact on strength properties and effluent characteristics. Oxygen delignification stage was incorporated prior to ClO 2 that resulted in improved optical properties of pulp with noticeable reduction in wastewater load. This paper elaborates the need of using sugarcane trash in paper mills with environment friendly pulping and bleaching processes to combat with the problem of waste management, wastewater load reduction during bleaching and substitute for wood based raw materials in papermaking. Highlights • Use of sugarcane trash for papermaking, an approach for waste management. • Soda pulping is an effective approach for converting waste to fibrous material. • Conventional bleaching leading to high effluent load and low strength properties. • Improvement in effluent quality and paper properties by chlorine dioxide bleaching. • Oxygen stage prior to dioxide bleaching further lowers effluent load. [ABSTRACT FROM AUTHOR]