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Title: Modelling and simulation of continuous hydrothermal flow synthesis process for engineering nano-materials
Author: Chen, Man
Awarding Body: University of Leeds
Current Institution: University of Leeds
Date of Award: 2013
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Continuous hydrothermal flow synthesis (CHFS) can be used to produce nanoparticles that have a wide range of applications. In this work, population balance (PB) and computational fluid dynamics (CFD) technique were used to assist CHFS process development. Laboratory-scale experimental studies have been conducted to identify the key parameters required for the computational model. As a result, a PB model was developed to estimate the particle size distribution (PSD). System kinetics including the hydrothermal reaction, material thermodynamics, and particle phenomena including nucleation, growth and agglomeration were studied using the PB model. The model gives similar mean particle size prediction compare to experimental data. The influences of precursor solution concentration and temperature on PSD were also evaluated. The results suggest an increased particle size at higher temperature and infeed concentration conditions. Regarding to the fluid flow field, a single phase CFD model was presented to study process flow dynamics and solution mixing profile. The PB model was coupled with the CFD model and applied to simulate CHFS processes in two reactor designs, namely counter-current reactor and confined jet mixer (CJM). The particle size and distributions, as well as particle impact on flow dynamics were studied. The modelling result suggests that particles produced in CJM reactor have smaller sizes and are more uniformly distributed, probably due to the enhanced flow dynamic at solution mixing zone. Meanwhile, the influence of operating conditions was also analysed. The condition of 400°C, 20/20 mLlmin is recommended as optimal operating condition for further scale-up study.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available