Highly efficient coke dust suppressant with anti-freezing capabilities.

Stockpiled coke is prone to wind-blowing emissions, leading to economic losses and environmental pollution which imposes severe threats to human health. While various polysaccharide-based dust suppressants have been explored to resolve this issue, they often suffer from ineffective control of wettability, poor coverage, and suppression effect in extreme weather conditions, and require additional use of cross-linking agents and surfactants due to their weak interaction with coke. Herein, we present coke dust suppressants comprising polyethyleneimine (PEI), starch, and glycerol to address these shortcomings. Our detailed investigations show that the low toxicity, cationic polymer (PEI) electrostatically interacts with the coke, increasing the wettability and promoting aggregation. Moreover, PEI hydrogen-bonds with starch to form a stable film and enhances the water-retention capability. Furthermore, the addition of glycerol lowers the freezing point to -13 °C, preventing coke loss caused by freezing during transportation and energy loss associated with dismantling the frozen coke. Wind erosion tests and bomb calorimeter results reveal that the coke dust suppressant exhibits superior wind resistance and does not interfere with the coke combustion.