Two-temperature model of the non-thermal chemical dissociation of CO2†

Abstract

A two-temperature model with a vibrational temperature different from the gas temperature is presented for the decomposition of CO₂. All vibrational modes of CO₂, CO and O₂ are included, and a novel procedure to calculate the vibrational–dissociation reaction rate constant is proposed. In all cases, a Boltzmann distribution is assumed for the vibrational states and the effect of the activation barrier on the chemical reactions is taken into account using the Fridman–Macheret expression. The non-thermal reaction rate constants are therefore functions of gas and vibrational temperatures. The results show that relatively higher vibrational temperatures benefit CO₂ conversion. This work provides more insights into the dissociation and recombination reactions of CO₂ conversion under non-thermal conditions and offers the opportunity for multi-dimensional non-thermal modelling in the future.