The conversion of light paraffins to olefins and the secondary reactions of the unsaturated compounds were investigated on H-ZSM5 and H-Y zeolites between 733 and 823 K. Steady stateand transient response-isotope tracing studies revealed that two mechanisms of dehydrogenation are operative. The main pathway is represented by monomolecular, protolytic dehydrogenation. This reaction contributes most to steady state olefin production. Additionally, at the initial stages of the reaction, extra framework aluminum moieties are speculated to participate in high dehydrogenation activity. This pathway is blocked at later stages of the reaction by product (hydrogen) inhibition. The intrinsic rates of protolytic dehydrogenation and olefin desorption range in the same order of magnitude. At high protolytic dehydrogenation rates, olefin desorption represents the rate determining step. Depending on the process conditions, olefins undergo secondary cracking, oligomerization, or isomerization. The latter proceeds via intramolecular rearrangement, possibly via a cyclopropylcarbenium ion at high temperatures and low conversions. At reaction conditions where bimolecular cracking prevails, isomerization is concluded to occur via secondary cracking of di-or oligomers.

Propylene glycol is converted to acrylic acid via dehydration to allyl alcohol. A process flow scheme is proposed, based on distillation resistance.

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The catalytic ox&&Ion of mtnc oxide to mtrogen &oxide m the presence of sulphur dioxide over a standard Pt/S102 catalyst (EuroPt-1) was stuched The gas-phase reactions between mtnc oxide, sulphur choxlde and oxygen were found to be ms~gmficant under the expenmental conditions concerned The Pt/S102 catalyst was observed to be very actwe m catalyzing the reactions both of NO+ 0, to NO, and of SO2 + 0, to SOS In the presence of sulphur diomde, the catalytic activity for mtnc oxide oxldatlon dropped dramatically, and m contrast, the presence of mtnc oxide promoted sulphur dioxide omdatlon There IS sqmficant mfluence of NO/NO2 on sulphur dioxide oxidation, there are m&cations from temperature-programmed desorptlon and temperature-programmed reduction (TPR) that some sort of complex species (e g [N,-S,-O,] ) ICI formed on the platmum Burface Deactmatjon of the catalyst was also observed dunng the act1vlt.y te& It 1s believed that the deactlvatlon of the catalyst wan malt& caused by the budd-up of some nitrogen and sulphur compounds on the actwe sites of the platmum catalyst Another reason for the deactwatlon could be the smtermg of platmum part&s m the reaction environment Thm has been confirmed by X-ray photoelectron spectroscopy, TPR and platmum dx+ persion measurements

It has been found that niobium pentoxide, calcined at temperatures between 500 and 700 "C, exhibits a high selectivity for the oxidative dehydrogenation of propane, although conversion is low; increasing the partial pressure of oxygen increases the conversion without decreasing the selectivity.

Carbon nanofibres (CNFs) and tungsten oxide (W18O49) nanowires have been incorporated into a continuous flow type microplasma reactor to increase the reactivity and efficiency of the barrier discharge at atmospheric pressure. CNFs and tungsten oxide nanowires were characterized by high-resolution scanning electron microscopy, transmission electron microscopy and nanodiffraction methods. Field emission of electrons from those nanostructures supplies free electrons and ions during microplasma production. Reduction in breakdown voltage, higher number of microdischarges and higher energy deposition were observed at the same applied voltage when compared with plane electrodes at atmospheric pressure in air. Rate coefficients of electron impact reaction channels to decompose CO2 were calculated and it was shown that CO2 consumption increased using CNFs compared with plane electrode in the microplasma reactor.