The dynamics of retained and deactivating species in a SAPO-18 catalyst during the methanol-to-olefins reaction have been followed using combination ex-situ in-situ techniques differential integral reactors.The were analyzed extraction, FTIR UV-vis spectroscopies combined with online product analysis (gas chromatography mass spectrometry). composition extracted soluble was determined gas chroma...

SAPO-34 is a commercially-implemented silicoaluminophosphate catalyst for selective high yield production of ethene and propene from methanol, but temperature regeneration in the presence steam leads to its deactivation. A comprehensive investigation effect prolonged hydrothermal treatment on structure properties explains changes catalytic methanol-to-olefins (MTO) performance. Microcrystalline...

The impact of nanopore diffusion on the performance of adsorption separation processes is reviewed. Zeolite membrane processes and kinetically selective cyclic adsorption processes depend for their selectivity on differences in intracrystalline diffusion rates so these processes are designed to operate under conditions of intracrystalline diffusion control. In contrast, the performance of equil...

In small-pore zeolite catalysts, where the size of the pores is limited by eight-ring windows, aromatic hydrocarbon pool molecules that are formed inside the zeolite during the Methanol-to-Olefins (MTO) process cannot exit the pores and are retained inside the catalyst. Hydrocarbon species whose size is comparable to the size of the zeolite cage can cause the zeolite lattice to expand during th...

Methanol-to-olefin (MTO) catalysis is a very active field of research because there is a wide variety of sometimes conflicting mechanistic proposals. An example is the ongoing discussion on the initial C-C bond formation from methanol during the induction period of the MTO process. By employing a combination of solid-state NMR spectroscopy with UV/Vis diffuse reflectance spectroscopy and mass s...

A series of catalysts based on hybrid intergrowth structure zeolites MFI-MEL, MFI-MTW, and MFI-MCM-41 are studied in the reaction olefins synthesis from dimethyl ether at atmospheric pressure a temperature 340 °C. The total acidity zeolite-based is shown to correlate with their activity. However, use zeolite MFI-MCM-41, which characterized by high content medium acid sites, additionally catalyz...

The synthesis of the ZSM-5 and beta zeolites in their nanosized form has been achieved by using simple alkyl-substituted mono-cationic cyclic ammonium cations as OSDA molecules. The particular combination of a cyclic fragment and a short linear alkyl-chain group (preferentially C4) within the monocationic OSDA molecules allows directing the crystallization of nanosized zeolites with excellent s...

The growing consumption of light olefins has stimulated intensive researches on methanol to olefin (MTO) process which possesses great advantages for coal conversion value-added chemicals in an environmentally benign way. catalysts commonly used MTO faces several challenges such as poor selectivity control, low hydrothermal stability and short lifetime. In the present study, we prepared a serie...

The product distribution of methanol to hydrocarbons conversion over SAPO-34 and ZSM-5 catalysts was studied using thermodynamic equilibrium and Anderson-Schulz-Flory (ASF) distributions. The equilibrium compositions were calculated using constrained Gibbs free energy minimization. The effect of catalyst type was considered by setting upper limits to product carbon number due to sh...