Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2018-2019)

Currently, the majority of kraft lignin is combusted as a low-grade energy source. Lignin valorization has been considered as a feasible option to make the pulping industry more profitable and prevent a major loss of resources. Efforts to produce value-added water soluble products including dispersants and flocculants from kraft lignin in Canada are mainly limited to Dr. Fatehi’s research program.
Dispersants and flocculants are water soluble chemicals with a wide range of industrial applications worldwide. Dispersants are mainly used to reduce viscosity of suspension or solution systems. Flocculants are widely employed in wastewater treatments to remove suspended particles and dissolved organic/inorganic chemicals. However, commercially available dispersants and flocculants are mainly oil-based, expensive, ineffective, environmentally unfriendly and non-biodegradable. For these reasons, the incentives for developing greener and more efficient lignin-based dispersants/flocculants are high in industry.
Lignin has a three-dimensional structure with several aliphatic and aromatic group attachments, making it amenable for producing dispersants/flocculants. Because of its chemical structure, lignin can be tailored to have a wide range of charge densities, molecular weights and degrees of hydrophilicity, making it possible to design dispersants/flocculants with a range of different properties and potential applications. The first objective of this research program is to identify the correlations between the properties of lignin-based dispersants/flocculants and their performance in various model solution and suspension systems. Results from this analysis will be used to support the second objective which is to design lignin-based dispersants/flocculants for various aqueous media. Upon success of this research program, the applicant should be able to design lignin-based dispersants and flocculants for various colloidal systems. Considering the urgent need for diversifying the use of kraft lignin (and thus increasing the revenues of kraft pulp mills) and the demand for using more environmentally friendly dispersants and flocculants in industry, it is expected that the technologies developed in this work will be taken up by kraft pulp mills soon. Supporting the kraft pulping industry through high-value products will secure Canada’s competitiveness in the global commodities market, and will bring stable jobs and greater prosperity to rural communities.