Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-IV-25THE STUDY OF METHANE DEHYDROAROMATIZATIONOVER W/HZSM-5 AND Ni-W/HZSM-5 CATALYSTSV.V. Kozlov 1 , L.L. Korobitsyna 1 , A.V. Vosmerikov 1 , G.V. Echevskyii 21 Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences3, Akademichesky Avenue, 634021, Tomsk, Russia2 Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences5, Ak. Lavrentieva Avenue, 630090, Novosibirsk, Russiafax: (7-3822) 491457, e-mail: kll@ipc.tsc.ruNatural and associated gases as energy carriers assumed ever greater importance use ofenergy resources. In accordance with long-term forecasts of the development of the globalenergetic balance, the global energy supply in the next 10 years will be of resources oforganic origin at the increase in the share of natural gas and decrease in the share of oil. Inthis connection the importance of effective technologies based on secondary processes of theprocessing of light hydrocarbon raw material will significantly increase.Catalytic methane conversion into a valuable petrochemical raw material is ofconsiderable interest as an interesting method for natural gas use.The investigation of the effect of some transition metals on the catalytic properties ofzeolite methane dehydroaromatization (DHA) has demonstrated that their activity decreasesin the following order: Мо > W > Fe > V > Cr [1-4]. At high temperatures that are necessaryfor methane DHA process Mo sublimation takes place resulting in the change in the catalystcomposition. For this reason in the process of methane conversion W characterized by muchhigher thermal stability should possess greater advantages over Mo.The studied catalysts were prepared by mechanical mixing of HZSM-5 zeolite withSiO 2 /Al 2 O 3 of 40 and nanosized W and Ni powders produced by wire electroexplosion inargon medium. W nanopowder content in the catalyst was varied from 3.0 to 10.0 wt %. Thecatalyst (1 cm 3 ) was placed on the quartz grid in the quartz reactor (d reactor = 12 mm) of a flowinstallation. The sample was heated in the helium flow to 750 °C and kept at this temperaturefor 20 min. Then the catalyst was treated with methane 99.9% pure at the temperature 750 °C,gas hourly space velocity 1000 h –1 and a small excess pressure. The reaction products weresampled by a dosing valve every 40 min and analyzed by gas chromatography.The activity of zeolite catalysts containing different amounts of W nanopowders wasstudied in the process of methane DHA. All the studied catalyst samples are characterized bya defined induction period, after which the catalyst activity reaches maximal values and thengradually decreases with reaction time. The 3.0% W/HZSM-5 has a smallest activity in440