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

PP-IV-24ONE-STAGE CATALYTIC CONVERSION OF NATURAL GASTO LIQUID PRODUCTSA.V. Vosmerikov 1 , L.N. Vosmerikova 1 , G.V. Echevskii 2 , L.L. Korobitsyna 11 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: (3822)491-457; e-mail: pika@ipc.tsc.ruNatural and associated gas, along with coal, oil and plant debris, has become the majorsource for the production of organic compounds [1]. Currently, most natural gas is used asfuel; its share in energy consumption is 24% [2]. The potentional value of natural gas is farhigher than a mere energy source. Natural gas can substitute for oil in the production of mostorganic compounds. Here, we report our studies of the catalytic properties of galliumcontainingzeolites, intercalated with gallium directly hydrothermal synthesis, in theconversion of natural gas to aromatic hydrocarbons.Galloaluminosilicates (Ga-AS) with silica ratios (M) from 30 to 80 were prepared by theisomorphic substitution of gallium (III) for silicon (IV) in the zeolite during hydrothermalsynthesis, via partially substituting gallium for aluminum ions in the precursor aluminosilicagel. The gallium oxide concentration in the sample was 1.2 or 2.2 wt %. The zeolitessynthesized were converted to the H-form by double decationization with a 25% NH 4 Clsolution at 90 °C for 2 h; they were dried at 110 °C for 8 h and calcined in air at 550 °C for 6 h.Natural gas had the following composition, wt %: methane, 81.60; ethane, 6.46; propane,7.40; butane, 4.04; and pentanes, 0.47. Conversion was carried out on a flow-through setupequipped with a silica glass reactor (14 mm in inner diameter) under the atmospheric pressureat the reaction temperature equal to 500-650 °C and the flow rate (W) equal to 1000 h –1 .Fig. 1 illustration the temperature effect on the product composition of natural gasconversion over the 2.2% Ga-AS (M = 60) catalyst at a gas flow rate of 1000 h –1 . The degreeof natural gas conversion and aromatic hydrocarbon yield increased with rising temperature to600 °C; the benzene, naphthalene, and alkylnaphthalene concentrations in the productincreased, while the toluene concentration decreased. The highest selectivity of aromatichydrocarbons formation (71.9%) was achieved on the 2.2% Ga-AS (M = 60) sample at600 °C. The degree of natural gas conversion was 2.1% higher than for 1.2% Ga-AS (M = 30)sample under the same conditions.438