Natural Surfactants for Flotation Deinking in Paper Recycling

The objective of this research was to evaluate new types of surfactants based on renewable materials (sugar and protein-based surfactants) for use in ink removal from recycled paper via flotation deinking. By applying green chemistry approaches we aim to minimize the environmental impact of deinking agents and also to open an avenue for a number of products that are to be generated from the utilization of biomass. Foamability and foam stability by the respective surfactants were considered and detergency experiments via piezoelectric sensing were used to unveil their fundamental differences in terms of surface activity. Lab scale flotation deinking efficiency was measured primarily by image analysis and flotation yield determined gravimetrically. We demonstrated that sugar-based surfactants are viable replacements to petroleum-based surfactants in flotation. Differences in flotation efficiency could be explained based on foaming, detergency and adsorption characteristics of the surfactants.