Infrared study of the carbochlorination ok MoO3 with Gaseous Chlorine

CRISTINA N. GUIBALDO; FEDERICO J. POMIRO; GEORGINA DE MICCO; ANA E. BOHÉ

THERMOCHIMICA ACTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 627 p. 9 - 19

0040-6031

In this work the kinetics of the carbochlorination ofmolybdenum trioxide with sucrose carbon at low temperatures (below 703 K) hasbeen studied by IR. A novel methodology for studying reaction kinetics isproposed based on on-line IR measurements of gaseous reaction products. Thistechnique allows identification of all the species involved in the reactionsystem which were not taking into account in previous studies. As predicted bythermodynamic calculations, the reaction proceeds by formation of CO2mainly, how-everformation of CO, COCl2, CCl4and HCl also takes place. The starting temperaturefor the reaction is determined at about 600 K. A reaction mechanism is proposedbased on the analysis of binary inter-actions between the reactants and theirmorphological changes during the reactions. The influence of carbon/oxideratio, gaseous flow rate, sample initial mass, temperature, and chlorinepartial pressure in the reaction rate was analyzed. Two kinetic regimes wereidentified, with activation energies of 203 ± 13and 36 ± 6 kJ mol−1which wereattributed to chemical reaction control (below 653 K) and mixed reaction controlat high temperatures. A reaction order of 0.5 with respect to chlorine partialpressure at 673 K was determined for the carbochlorination reaction.