Plantwide control structure for methanol process

Abstract

The presence of material and energy recycles poses a significant problem in the plantwide control structure design (PWCD) which involves with an entire chemical plant control system. Methanol can be produced from the synthesis gas which is made from renewable energy source (biomass) by partial oxidation in gasifier. The methanol process is selected for testing PWCD because it is a complex multi-unit process. This research focused on the development control structures for methanol process by using Wongsri’s procedure (2009). A steady state and dynamics simulations are done via Aspen Plus and Aspen Dynamics respectively. Three control structures (CS1 to CS3) are designed and evaluated dynamic performance to compare with the proposed control structure of Luyben (2010) by using material and thermal disturbances. The result shows that the dynamic responses of the designed control structures and base control structure are similar as compared by integral absolute error (IAE). All designed control structures with heat integration can reduce the energy consumption, can reject disturbances, and can maintain product quality close to their specified values.