Ketene (CH2=C=O) has been postulated as a key intermediate for the first olefin production in zeolite-catalyzed chemistry of methanol-to-olefins (MTO) and syngas-to-olefins (STO) processes. The reaction mechanism remains elusive, because short-lived ethenone ketene its derivatives are difficult to detect, which is further complicated by low expected concentration. We report on experimental dete...

New experimental techniques of in situ MAS NMR spectroscopy introduced in the past decade made this analytical method to a useful tool for the study of heterogeneously catalyzed reactions. Batch and flow techniques were applied to study reactions catalyzed by basic and acidic solids. The present review introduces into in situ MAS NMR investigations of transition states, e.g., via the H/D exchan...

ABSTRACT The successful development and application in industry of methanol-to-olefins (MTO) process brought about an innovative efficient route for olefin production via non-petrochemical resources also attracted attention C1 chemistry zeolite catalysis. Molecular sieve catalysts with diversified microenvironments embedding unique channel/cavity structure acid properties, exhibit demonstrable ...

The catalytic activity of large zeolite H-ZSM-5 crystals in methanol (MTO) and ethanol-to-olefins (ETO) conversions was investigated and, using operando UV/Vis measurements, the catalytic activity and deactivation was correlated with the formation of coke. These findings were related to in situ single crystal UV/Vis and confocal fluorescence micro-spectroscopy, allowing the observation of the s...

H-ZSM-5 zeolite is a typical catalyst for methanol-to-olefins (MTO) conversion. Although the performance of catalysts MTO conversion related to actual location acid sites in framework, catalytic roles different pore channels are not well understood. In this study, reaction network, involving aromatic cycle, alkene and aromatization process, also diffusion behavior methanol feedstock olefin prod...

• ERI-type molecular sieves enhance ethylene selectivity in MTO . Acidity significantly influences ethylene-to-propylene ratio materials. Changes acidity alter hydrocarbon-pool species concentration and composition. Low acid site densities hinder the formation of aromatics (thus, ethylene) ERI. (SSZ-98, UZM-12, zeolite, SAPO-17) are synthesized with varying Si/Al = 5–9 Si/T-atoms 0.034–0.12 usi...

Operando UV/Vis spectroscopy with on-line mass spectrometry was used to study the effect of different types of impurities on the hydrocarbon pool species and the activity of H-SAPO-34 as a methanol-to-olefins (MTO) catalyst. Successive reaction cycles with different purity feedstocks were studied, with an intermittent regeneration step. The combined study of two distinct impurity types (i.e., f...

As a significant reaction in heterogeneous catalysis, methanol-to-hydrocarbon (MTH) conversion supplies sustainable way for the production of important platform chemicals, e.g., olefins, gasoline and aromatics. Although many commercial MTO plants have already been operated China recently, catalytic efficiency, i.e., olefins selectivity catalyst lifetime still need to be improved. Consequently, ...

In this research, modeling, simulation, and control of a methanol-to-olefins laboratory fixed-bed reactor with electrical resistance furnace have been investigated in both steady-state and dynamic conditions. The reactor was modeled as a one-dimensional pseudo-homogeneous system. Then, the reactor was simulated at steady-state conditions and the effect of different parameters including...