Control structure design of biodiesel production process with phase split and recycle in the reactor system

Abstract

This work studies control structure design of a biodiesel production process with phase split and recycle in the reactor system. Triglyceride reacts with methanol to form methyl esters and glycerol. The process is optimized to minimize total equivalent energy subject to 30 optimization constraints. The optimization result shows that the energy required is about 371.43 kW. To avoid the control constraint violation while the process is operated dynamically, the process is backed-off making the energy required increases to 445.67 kW. A presence of the material recycles and energy integrations make the process has more complexity in dynamic behavior; therefore, the control system is designed in plantwide perspective using Wongsri’s plantwide control design procedure. The simulation result shows that six viable control structures have good control performances. The control performances of all control structures are evaluated in term of the weighted integral absolute errors. In addition, utility requirements for all control structures are about the same.