Synthesis of Dimethyl Ether from Synthesis Gas over the Megamax 507/γ-Al2O3 Catalyst

Abstract

A laboratory flow setup loaded with a bifunctional catalyst was used for kinetic studies of the direct synthesis of dimethyl ether (DME) from synthesis gas (21.8 vol % CO, 5.2 vol % CO₂, 5.3 vol % N₂, rest H₂) at the pressure range of 0.2–5 MPa. The bifunctional catalyst was prepared by tabletting a mixture of milled fractions of industrial components: methanol catalyst Megamax 507 and γ-alumina with a graphite additive. The data on the activation of the bifunctional catalyst agree with the TPR data of the initial Megamas 507 that indicates no influence of the catalyst preparation conditions on the copper oxide state. The oxygenate (DME and methanol) production rate increases linearly with increasing load at temperature up to 280 °C and flow rate up to 4000–10000 L/(kgcat·h) at pressure of 3 to 5 MPa. An increase in load leads to reaching the limit value that allows the estimation of the maximal oxygenate production rate of the catalyst depending on temperature and pressure. A series of experimental data on the influence of flow rate, temperature, and pressure on the composition of the converted gas and on the DME/methanol ratio are reported.