Synthesis of dimethyl ether using a fixed bed of dual catalyst for methanol synthesis and its dehydration

Experimental study on direct synthesis of DME (dimethyl ether) has been conducted using tubular reactor. The synthesis of DME was performed with two commercial catalysts, ie methanol synthesis catalyst (M151, Cu-based) and methanol dehydration catalyst (gamma-Al2O3). A mixture of H-2, CO, and N-2 was used as a model for synthesis gas. Gas flow rate was set at 20 mL/min (5 bar and 240 degrees C). The reaction held at: pressure of 5 bar and a temperature of 240 degrees C. This experiment was conducted by arranging a series of two types of catalysts in a fixed bed reactor. The methanol synthesis catalyst was placed in the upstream to ensure the reaction of methanol formation, then proceed with dehydration of methanol to DME. The objective of this experiment was to find out the best dual catalyst composition to produce a high concentration of DME. The experiment has shown that the best combination of methanol catalyst to dehydration catalyst was a mixture of 20% methanol catalyst (ratio 1/4). CO conversion was 62% and the product ratio of DME/methanol was 40%.