Thermal decomposition of selected chlorinated hydrocarbons during gas combustion in fluidized bed

BACKGROUND: The process of thermal decomposition of dichloromethane (DCM) and chlorobenzene (MCB) during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C(6)H(5)CI, CH(2)Cl(2), CO(2), CO, NO(x), COCl(2), CHCl(3), CH(3)Cl, C(2)H(2), C(6)H(6), CH(4) in the flue gases were specified versus mean bed temperature. RESULTS: The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. CONCLUSIONS: Taking into account possible combustion mechanisms, it was identified that autoignition in bubbles rather than flame propagation between bubbles is needed to achieve complete destruction of DCM and MCB. These condition occurs above 900°C causing the degree of conversion of chlorine compounds of 92-100%.