Education History

This research addresses modeling and control of yield and size distribution in particulate processes. We use a novel method of solar-grade silicon production, the thermal decomposition of silane gas in a fluidized bed reactor, as a benchmark. We have developed a model and control scheme for the behavior of particles in a fluidized bed reactor based on silicon production. The model simulates growth of silicon particles with ordinary differential and algebraic equations that track particle movement through discrete size intervals. The model solves quickly and is easily tuned to fit experimental data. The passivity-based inventory controller maintains a constant mass of a specified size of silicon particles.

In the future, we will link the current size distribution model to a model for gas-solid fluidization to better represent the system. We will also extend the model to include a better representation of the effect of nucleation. The improved model will be used to develop control of the gas and solid flows in the reactor as well as the silicon yield. To address control of this model and particulate processes in general, we will establish required state and parameter estimators. We will also check the generality of our methods on a different particulate process such as the production and growth of biological cells or atmospheric aerosols.

Presentations
“Modeling and control of size distribution for fluidized bed silane decomposition,” AIChE Annual Meeting, Austin, TX, November 2004

“Photocatalytic Decomposition of Formic Acid on 0.2% Pt/TiO2,” AIChE Annual Meeting, Los Angeles, CA, November 2000