(71j) Process Control of Micro Chemical System for Steam Reforming Reaction

As the attempts to reduce the size of chemical process capture chemical engineers' interest, there are significant requirements of control strategies utilizing miniaturized components. After considerable research efforts to reduce the size of chemical reactors, similar efforts are needed to integrate control elements into complete chemical process units. While many MEMS-based examples exist of sensors and actuators for control of pressure, temperature, and flow, there are few cases where these components have been integrated together with reaction units and control algorithms, even in very basic forms. The ultimate goal of chemical process miniaturization is the optimization of processes in order to gain maximum outcome from a minimum of expenditure and under the constraints of minimal volume and mass requirements. Such systems are attractive for portable applications or where size and weight are at a premium, for example, in advanced automotive or aerospace applications. Such constraints are unique to process miniaturization as distinct from process intensification where microscale reaction geometry is essential, but overall system size is not strictly constrained. In this context, we present the results of an investigation of an integrated microchemical system which includes microfabricated flow sensors, temperature sensors, and heating elements with a silicon microreactor and process control algorithms for autonomy. Each component is interfaced with Labview control software and communicates via specific schemes implemented in the software. In this work, catalytic steam reforming of methanol is used as a model reaction. We will present detailed results of this study.