Rheological and Stability Assessment of Alternative Polymer Modifiers for Coal Dust Combustion

This study focuses on the development and physicochemical evaluation of an alternative liquid carrier for coal dust combustion modifiers containing solid catalyst particles. A commercially used acrylic-polymer-based carrier, whose viscosity is regulated by sodium hydroxide addition, was investigated and compared with a proposed safer substitute based on an aqueous sodium carboxymethyl cellulose (Na-CMC) solution. Rheological properties were measured in the shear-rate range relevant to industrial transport and injection systems, while sedimentation behavior was assessed using image-based analysis. The results show that the Na-CMC carrier exhibits shear-thinning behavior and viscosity levels comparable to the commercial formulation, enabling stable suspension of catalyst particles without the need for alkali additives. Unlike the reference system, the alternative carrier does not generate gas during storage, eliminating potential safety hazards associated with hydrogen evolution. Although no direct combustion experiments were performed, the obtained rheological and stability characteristics indicate that the proposed Na-CMC-based carrier is suitable for short-term storage and injection of catalyst-containing modifiers in coal dust combustion systems. Direct validation of combustion performance is planned in future work.