Selective Coke Combustion by Oxygen Pulsing During Mo/ZSM-5-Catalyzed Methane Dehydroaromatization.

ABSTRACT: Non-oxidative methane dehydroaromatization is a promising reaction to directly convert natural gas into aromatic hydrocarbons and hydrogen. Commercialization of this technology is hampered by rapid catalyst deactivation because of coking. A novel approach is presented involving selective oxidation of coke during methane dehydroaromatization at 700?°C. Periodic pulsing of oxygen into the methane feed results in substantially higher cumulative product yield with synthesis gas; a H₂ /CO ratio close to two is the main side-product of coke combustion. Using ¹³ C isotope labeling of methane it is demonstrated that oxygen predominantly reacts with molybdenum carbide species. The resulting molybdenum oxides catalyze coke oxidation. Less than one-fifth of the available oxygen reacts with gaseous methane. Combined with periodic regeneration at 550?°C, this strategy is a significant step forward, towards a process for converting methane into liquid hydrocarbons.

SUBMITTER: Kosinov N 

PROVIDER: S-EPMC5132063 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature