Analysis, synthesis, and design of a one-step dimethyl ether production via a thermodynamic approach

In this work, we have developed a direct one-step process design on an oxygenate production, namely, dimethyl ether (DME). DME can be used as a cetane-number booster for diesel, in addition to being capable of a substitute for liquefied petroleum gas (LPG). In order to analyze the independent chemical reactions involved in the reactor, it is necessary to carry out a study of the chemical reaction stoichiometry. And with a specific syngas feed, the following reactions are found: (1) CO2+H2=H2O+CO, (2) CO+2H2=CH3OH, and (3) 3CO+3H2=(CH3)2O+CO2. To gain an insight into the reactor design, we have also utilized the concept of thermodynamics, including equilibrium-constant method and the minimization of Gibbs free energy. Additionally, we have also united the pinch technology with the base-case design for heat exchanger network synthesis in order to compare the energy consumption and capital costs of the process with/without heat integration. Two kinds of software were used in the research–Aspen Plus and SuperTarget. The former was used for the process synthesis, design, and simulation; the latter was used to carry out the pinch analysis and the synthesis of heat exchanger network.