Batch Crystallization Kinetics of Ammonium Sulfate from Saturated Solution Under Controlled Cooling Rate

Abstract

Batch crystallization is a widely applied separation and purification technique in chemical and fertilizer industries, where crystallization kinetics strongly influence crystal quality, particle size distribution, and process efficiency. The present study investigates the crystallization kinetics of ammonium sulfate from saturated aqueous solution under controlled cooling conditions, with emphasis on nucleation behavior, crystal growth characteristics, and process optimization. Experimental analysis was conducted to evaluate the effects of cooling rate, supersaturation level, agitation intensity, and solution concentration on crystallization performance and product morphology. Results demonstrate that controlled cooling significantly affects supersaturation generation and nucleation dynamics, thereby influencing crystal size distribution and overall crystallization efficiency. Lower cooling rates were observed to promote uniform crystal growth and larger crystal formation, while rapid cooling conditions increased nucleation frequency and produced finer crystals with broader particle size distribution. The study further examines the relationship between heat transfer conditions and mass transfer mechanisms during batch crystallization, highlighting their role in determining crystal purity and operational stability. Kinetic modeling and experimental observations indicate that optimized cooling strategies improve crystal yield while minimizing agglomeration and impurity incorporation. Comparative assessment with uncontrolled crystallization processes confirms that precise thermal regulation enhances product consistency and reduces downstream processing requirements. In addition, the findings demonstrate the importance of controlled operating parameters for improving industrial ammonium sulfate production and process sustainability.