III International Conference

PP-II-56NON-OXIDATIVE METHANE CONVERSION TO AROMATIC HYDROCARBONSON W-HZSM-5 CATALYSTSKorobitsyna L.L., Kozlov V.V., Zaykovskii V.I. 1 , Vosmerikov A.V., Echevsky G.V. 1Institute of Petroleum Chemistry SB RAS, Tomsk, Russia1 Boreskov Institute of Catalysis SB RAS, Novosibirsk, RussiaE-mail: kll@ipc.tsc.ruThe conversion of methane to aromatics in the absence of oxygen has been investigatedat the reaction temperature of 750 о C over zeolite catalysts modified by W nanopowder. It hasbeen established that the highest methane conversion per one run and maximal yield ofaromatics are reached for the sample containing 8.0% W nanopowder. The W-HZSM-5catalysts were studied by high-resolution transmission electron microscopy and energydispersive X-ray analysis. The distribution and condition of the active species wereinvestigated. The catalyst was deactivated in methane aromatization resulting of graphitecondensation on catalyst surface. The nature of coke deposition was studied.Recently, direct conversion of methane to higher hydrocarbons over zeolite catalystsmodified with transition metal ions has attracted increasing attention [1-3]. In this connectionthe study into the catalyst deactivation occurring during the methane conversion reactionrepresent a significant research and practical interest, methane being the main component ofnatural and associated gases.The activity of zeolite catalysts containing different amounts of W nanopowders wasstudied in the process of methane dehydroaromatization (DHA). The catalyst samples understudy were produced via mechanical mixing of ZSM-5 zeolite (with the silicate modulus 40)with W nanopowders produced via wire electroexplosion in inert medium. The highest valueof methane conversion is reached over zeolite containing 8.0% W. The catalyst (1 cm 3 ) wasplaced on the quartz grid in the quartz reactor (d reactor =12 mm) of a flow installation. Thesample was heated in the helium flow to 750 o C and kept at this temperature for 20 min. Thenthe catalyst was treated with methane 99.9% pure at the temperature 750 o C, gas hourly spacevelocity 1000 h -1 and a small excess pressure. The methane conversion and arene yield passthrough maxima (12.1 and 9.0% respectively) at a reaction time of 100 min, and then theactivity of the catalyst begin to decrease.The study into morphology and chemical composition of W-HZSM-5 were carried out byhigh-resolution transmission electron microscopy (HRTEM) and Energy Dispersive X-ray265