CATALYTIC COMBUSTION OF METHYLENECHLORIDE

The catalytic combustion of methylenechloride, one of the chloromethan es, was investigated on metal oxide catalysts coated on the monolith s upport or on the spherical alumina pellets. The prepared catalysts wer e tested at the different temperatures between 200 and 500 degrees C a nd at varying GHSV values with an excess air of 216%. The catalyst hav ing the composition of 15% Cr2O3, 5% Ce2O3 and 80%gamma-Al2O3 on the m onolith was found to be ultimate due to the complete destruction of me thylenechloride and to the highest mechanical stability. The operating conditions were proposed as 77778 h(-1) for the GHSV, 216% for the ex cess air and 400-500 degrees C for the temperature range to combust me thylenechloride completely. The dependency of the reaction on methylen echloride and oxygen partial pressures was searched, and it was determ ined that the rate was strongly dependent on oxygen partial pressure a nd weakly methylenechloride partial pressure. The reaction rate expres sion was derived using the mechanism proposed by Downie and the reoxid ation and reduction rate constants of the reaction were found as: k(i) = 4.422 x 10(-5)exp(-12597.5/RT) K-0 = 2.901 x 10(-6)exp(-4552.5/RT).