Thesis (M.Eng.)--Chulalongkorn University, 2009

Chemical process control structure was studied widely to optimized economic under various process object constrains and environment safety. This research is applied "Fixture point theorem" to ethyl benzene process to design a new plantwide control structures that be compared with Luyben (2002). The principle of the fixture point theorem is the most disturbed variables were affected by manipulated variables or disturbances change should be precedence consideration. We selected two of controlled variables and three control structures were designed and compared. The dynamic behaviors of designed control structures were illustrated whether mainpulated variables change and the performance were presented in IAE value. The design control structure had a good performance and energy use reduction in the process. This research establishes that the Wongsri's procedure lead to a good performance plantwide control system