Synthesis of dimethyl ether (DME) by catalytic distillation

• Published in: Chemical engineering science Vol. 66; no. 14; pp. 3195 - 3203
• Main Authors: Lei, Zhigang, Zou, Zhiwu, Dai, Chengna, Li, Qunsheng, Chen, Biaohua
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 15.07.2011; Elsevier
• Subjects: acetone; Applied sciences; Catalysis; Catalysts; Catalytic distillation; Catalytic reactions; Chemical engineering; Chemistry; Columns (process); Dimethyl ether (DME); Distillation; energy; Exact sciences and technology; General and physical chemistry; Ion exchange; ion exchange resins; Mathematical modeling; Mathematical models; methanol; Methyl alcohol; Multiphase reactors; Reaction engineering; Reaction kinetics; Reaction mechanism; Reactors; sulfonic acid; temperature; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Dimethyl ether (DME); Reaction mechanism; Multiphase reactors; Mathematical modeling; Catalytic distillation; Reaction engineering; Energy consumption; Purity; Liquid phase; Dehydration; Modeling; Microreactor; Mathematical model; Distillation column; Ion exchange resin; Distillation; Catalytic reaction; Fixed bed reactor; Persistence; Kinetic model; Lifetime; Production capacity; Kinetics; Catalyst; Macroporosity
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2011.02.034

The intrinsic kinetics of liquid phase catalytic dehydration of methanol to dimethyl ether over a macroporous sulphonic acid ion exchange resin was determined in a fixed-bed micro-reactor in the temperature range of 391–423 K and pressures up to 2.0 MPa. The kinetic model based on Eley–Rideal mechanism, as well as the power-rate law model, was adopted for fitting the experimental data. However, the Langmuir–Hinshelwood mechanism is not feasible for describing the dehydration reaction of methanol, as deduced from the macroscopic kinetic data and/or no dependence of methanol conversion on initial methanol concentration in the absence of water at the inlet using acetone as inert solvent. Moreover, an improved process consisting of the combination of a fixed-bed reactor and a catalytic distillation column for the synthesis of DME (Process A) was proposed, and a mathematical model was established, into which the intrinsic kinetics obtained in this work was incorporated. The comparison of operating performance among the improved process, Process B consisting of a fixed-bed reactor and two ordinary distillation columns, and Process C consisting of a catalytic distillation column and an ordinary distillation column was also made. It was found that the improved process is more promising than others in energy consumption, production capacity and column number under the same product purity, and is easy to be implemented based on Process B that is currently used in the actual industrial plants with a long catalyst lifetime.