Modelling and simulation of continuous hydrothermal flow synthesis process for nano-materials manufacture

Continuous hydrothermal flow synthesis (CHFS) technology has shown great advantages in nanomaterial formulation compared with other synthesis methods. CHFS uses a flow of supercritical water as a reagent that reacts with a flow of metal salts to produce nanoparticles in a reactor. The process uses no organic solvent, therefore is green, and has good controllability due to being in continuous operational mode. Experimental studies have shown that very high quality nanoceramics can be made in minutes rather than days. This paper describes simulation studies of the reaction and precipitation in a CHFS process using population balance modelling technique. Models for reaction kinetics, thermodynamics and nucleation are presented. Particle surface growth mechanism and particle aggregation effects have also been taken into consideration in the population balance models. System kinetics and the dynamic evolution of particle size distribution under supercritical conditions were simulated. The effects of temperature, aggregation and growth rate on particle size distribution were also investigated.