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

• Published in: Applied energy 2013-01, Vol.101, p.449-456
• Main Authors: Chen, Hsi-Jen, Fan, Chei-Wei, Yu, Chiou-Shia
• Format: Article
• Language: English
• Subjects: Alternative fuels. Production and utilization; Applied sciences; capital; Carbon dioxide; Carbon monoxide; Chemical reactions; Clean energy; computer software; Design engineering; Dimethyl ether; Energy; Energy savings; Exact sciences and technology; Fuels; Gibbs free energy; heat; Heat exchangers; Hydrogen; liquid petroleum gas; Miscellaneous; Pinch technology; process design; Process synthesis and design; stoichiometry; Synthesis; synthesis gas; Thermodynamics
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2012.08.025

► We analyze a one-step DME production via a thermodynamic approach. ► We synthesize a one-step DME process. ► We design a one-step DME process with pinch technology. 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.