Modeling and predictive control of a rotating disk bioreactor

A rotating disk bioreactor (RDB) produces cohesive cellulose gels rapidly because of the high surface area, high volumetric efficiency, and low power consumption. A novel feature of the RDB that we have developed is that solids added to the medium enter the gel and are held at selected locations. Different solid materials such as silica gel, glass spheres, metallic powders, carbon, and common plant cellulose can be incorporated into the gel and gradients, stripes or bands of solids can be formed, resulting in a new type of biomaterial with applications in foods, medicine, bioprocessing, and manufacture of novel forms of paper. Incorporation of solid particles into the gelatinous matrix of bacterial cellulose involves complicated fluid/particle hydrodynamics. Experimental results are shown for a semibatch RDB, while simulation studies apply model predictive control (MPC) to a continuous RDB. Two MPC approaches are developed and analyzed for setpoint tracking and disturbance rejection.