III International Conference

PP-III-25PARTIAL OXIDATION OF PROPANE-BUTANE MIXTURE IN MINI REACTORSSheludyakov Y.L., Zharmagambetova A.K., Abuova N.D.V. Sokolsky Institute of Organic Catalysis and Electrochemisrty MS&HE RK,Almaty, Republic of KazakhstanE-mail: Shelud@nursat.kzPartial oxidation of propane-butane mixture with oxygen has been studied in quartz minireactorsover heated Ni-Cr-Fe wire. Within short contact times conversion of hydrocarbons isup to 89 %, however, concentration of СО 2 in the products does not exceed 3 %. Among themain products are hydrocarbons with shorter C-C chain, hydrogen, CO and liquid oxygencontaining hydrocarbons.Partial oxidation of propane-butane mixture with oxygen has been studied at volume flowrate of 500000 h -1 over Ni-Cr-Fe wire.The wire was heated up to 1000 o С with electric current; in steady state its temperaturecould be maintained without electricity due to exothermic reactions on its surface if the ratioО 2 :C x H 2x+2 is more than one.Experiments in the reactors with different volumes showed that conversion ofhydrocarbons is growing from 15 to 89 % together with increase of surface : volume ratio ofthe reactor. Conversion of hydrocarbons is always more than conversion of oxygen. Whenconversion of butane is 74 % conversion of oxygen is approximately 45 %.Stoichiometry of the reaction is as follows:С 3 Н 8 + 3i-С 4 Н 10 + 8С 4 Н 10 + 8О 2 = 4Н 2 + 5СО + СО 2 + 3СН 4 + 3С 2 Н 6 + С 2 Н 4 + liquidoxygen containing hydrocarbons and water.Study of the effect of volume and shape of the reactors on the rate of conversion lead toestablish that most part of processes (up to 75 %) proceed over the hot wire and neighboringhot surfaces. However, part of chemical reactions proceeds also in the volume and over coldsurfaces. Therefore, the zone in proximity to the wire (less than 0.06 cm 3 ) could be considereda micro-reactor where conversion of the gas mixture proceeds within millisecond time span.Even at high conversion of initial gas mixture only small percent of СО 2 was registered inthe products (less than 3 %) i.e. partial oxidation is the prevailing process.Electron microscopy showed that surface of the wire is covered with complex mixture ofnickel, chromium and iron oxides.Introduction of water vapor to the initial gas mixture leads to increase percentage ofhydrogen in the products.Scheme of the mechanism of radical and surface reactions is proposed.515