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The activity of dimethyl ether (DME) hydrolysis was investigated over a series of solid acid and non-acid catalysts, zeolite Y [Si/Al = 2.5 and 15: denoted Y(Si/Al)], zeolite ZSM-5 [Si/Al = 15, 25, 40, and 140: denoted Z(Si/Al)], silica, zirconia, γ-alumina, and BASF K3-110 (commercial Cu/ZnO/Al 2 O 3 catalyst). Dimethyl ether hydrolysis was carried out in an isothermal packed-bed reactor at ambient pressure. Acid catalyzed dimethyl ether hydrolysis is equilibrium limited. All solid acid catalysts, with the exception of ZrO 2 , attained equilibrium-limited conversions in the temperature range of interest (125–400 °C). Z(15), Z(25), and Z(40) reached equilibrium conversions at 200 °C, while Z(140), Y(15), and Y(2.5) reached equilibrium at 275 °C. γ-Alumina, the most active non-zeolite solid acid, attained equilibrium at 350 °C. Silica and BASF K3-110 were both ineffective in converting dimethyl ether to methanol. The observed activity trend for DME hydrolysis to methanol as a function of Si–Al ratio and catalyst type was: Z ( 15 ) Z ( 25 ) Z ( 40 ) > Z ( 140 ) Y ( 15 ) > Y ( 2.5 ) ≫ γ -A l 2 O 3 > Zr O 2 . |
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