Analysis of the Reaction Rate Coefficients for Slow Bimolecular Chemical Reactions

TL;DR

This paper analyzes the initial reaction rate coefficients of simple bimolecular reactions using the Boltzmann equation, focusing on non-equilibrium effects and the influence of molecular velocity distributions.

Contribution

It applies the Chapman-Enskog method to evaluate how non-Maxwellian distributions affect reaction rate coefficients in bimolecular reactions.

Findings

Non-Maxwellian velocity distributions significantly influence reaction rates.

Activation-energy dependent cross sections alter forward and reverse reaction coefficients.

Results provide insights into reaction kinetics far from equilibrium.

Abstract

Simple bimolecular reactions $A_1+A_2\rightleftharpoons A_3+A_4$ are analyzed within the framework of the Boltzmann equation in the initial stage of a chemical reaction with the system far from chemical equilibrium. The Chapman-Enskog methodology is applied to determine the coefficients of the expansion of the distribution functions in terms of Sonine polynomials for peculiar molecular velocities. The results are applied to the reaction $H_2+Cl\rightleftharpoons HCl+H$, and the influence of the non-Maxwellian distribution and of the activation-energy dependent reactive cross sections upon the forward and reverse reaction rate coefficients are discussed.