ie9b03344_si_001.pdf (1.8 MB)
Influence of Precursors on the Induction Period and Transition Regime of Dimethyl Ether Conversion to Hydrocarbons over ZSM‑5 Catalysts
journal contribution
posted on 2019-08-25, 20:13 authored by Toyin Omojola, Dmitry B. Lukyanov, Nikolay Cherkasov, Vladimir L. Zholobenko, André C. van VeenZSM-5 catalysts were subjected to
step response cycles of dimethyl
ether (DME) at 300 °C in a temporal analysis of product (TAP)
reactor. Propylene is the major olefin and displays an S-shaped profile.
A 44 min induction period occurs before primary propylene formation
and is reduced upon subsequent step response cycles. The S-shaped
profile was interpreted according to induction, transition-regime,
and steady-state stages to investigate hydrocarbon formation from
DME. The influence of precursors (carbon monoxide, hydrogen, dimethoxymethane,
and 1,5-hexadiene) was studied using a novel consecutive step response
methodology in the TAP reactor. The addition of dimethoxymethane,
carbon monoxide, hydrogen, or 1,5-hexadiene reduces the induction
period of primary olefin formation. However, while dimethoxymethane,
carbon monoxide, and hydrogen accelerate the transition regime toward
hydrocarbon pool formation, 1,5-hexadiene attenuates it. Heavier hydrocarbons
obtained from 1,5-hexadiene compete for active sites during secondary
olefin formation. A phenomenological evaluation of multiple parameters
is presented.