Thesis (M.Eng.)--Chulalongkorn University, 2008

Dimethyl ether (DME) is a clean and economical alternative fuel which can be produced from natural gas through synthesis gas. The properties of DME are very similar to those of LP gas. DME can be used for various fields as a fuel such as power generation, transportation, etc. In this research we present heat integrate plant (HIP) for three alternatives using disturbance propagation method is provided by Wongsri (1990) and three new plantwide control structure of DME process using Lyben (1998)'s heuristics and fixture point method to compare with Base Case of DME process to minimize energy usage and best control structure. From the result, HIP2 is the best alternative because it can be saved energy 58.8% and control structure 3 is the best plantwide control structure to give the minimize IAE score. HYSYS 3.1 was used to simulate the DME production process in both steady state and dynamic modes, PID controller are provided to control in this process.