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Abstract: SAPO-34 molecular sieves were fabricated by a dry gel liquid-phase transport method using morpholine (Mor) or morpholine–tetraethylammonium hydroxide (Mor–TEAOH) as the structure-directing agent (SDA). The prepared samples were characterized by scanning electron microscope (SEM), nitrogen adsorption–desorption, X-ray diffraction (XRD), ammonia temperature-programmed desorption (NH3-TPD), thermo-gravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR). The results indicated that the dry gel liquid-phase transport method is very effective to fabricate SAPO-34 molecular sieves with average crystal size about 0.6μm using Mor–TEAOH as SDA and 3μm using Mor as SDA, respectively. Moreover, the addition of TEAOH is beneficial to produce SAPO-34 with small crystal size. Methanol-to-olefins (MTO) reaction was chosen to test the catalytic performance of as-prepared SAPO-34 catalysts. The prepared SAPO-34 catalyst using Mor–TEAOH as SDA exhibited the excellent catalytic performance in MTO process owing to its small crystal size and high crystallinity. The conversion of methanol and selectivity of ethylene and propylene are up to 100% and 87.9%, respectively. [Copyright &y& Elsevier]

We investigated the isobaric vapor-liquid equilibria (VLE) of the binary system methanol + tetrahydrofuran (THF), the ternary system methanol + THF + 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][NTf 2 ]), as well as methanol + THF + 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][NTf 2 ]) in a modified Othmer still. The results indicated that the ionic liquids ([BMIM][NTf 2 ] and [HMIM][NTf 2 ]) produced a consistent salting-in effect of THF, resulting in the incremental relative volatility of methanol to THF. The experimental data were correlated using the e-NRTL model, and the parameters were obtained with a good consistency. The ionic liquids even eliminated the azeotropic phenomenon when the mole ratio of [BMIM][NTf 2 ] was up to 0.173 and [HMIM][NTf 2 ] up to 0.128 as calculated by the e-NRTL model. [HMIM][NTf 2 ] had a stronger effect on the separation of azeotropic mixtures than [BMIM][NTf 2 ] did. [ABSTRACT FROM AUTHOR]