Optimization and control of dynamic bioprocesses

For many applications, such as commodity chemical production, ore leaching, waste treatment, and environmental remediation, bioprocesses can be less e xpensive, more energy-efficient, and more environmentally friendly than con ventional processes. The key to effective implementation of bioprocesses is rational design, optimization, and process control. We are applying the to ols of intelligent systems to develop supervisory systems for the optimizat ion and control of continuous, dynamic, and uncharacterized bioprocesses. W e have designed, built, and evaluated hierarchical hardware and software sy stems for the control of microbial oxidation of soluble iron in a continuou s stirred tank reactor. The supervisory control module uses stochastic lear ning to determine what system parameters (i.e., pH, dilution rate, and temp erature) should be, based on the state of the system. An expert-based flow- rate controller optimizes reactor performance for each set of system parame ters. Theoretically, high reactor conversion can be obtained much faster by varying these multiple parameters simultaneously as opposed to the traditi onal method of varying a single parameter at any given instance.