Adsorption and the Chemical Reaction N₂O₄ ↔ 2NO₂ in the Presence of N₂ in a Gas Phase Connected with a Carbon Nanotube

Abstract

The paper shows, by molecular simulations, that a CNT (9,9) carbon nanotube allows very efficient separation of nitrogen oxides (NO x ) from N 2 , that has in good approximation properties of the complete air mixture. Gibbs ensemble Monte Carlo simulations are used to describe the adsorption. The permanent chemical reaction between N 2 O 4 and NO 2 , which occurs simultaneously to adsorption, is treated by the reactive Monte Carlo simulation. A very high selectivity has been found. For a low pressure and at T = 298 K, an adsorption/reaction selectivity between NO x and N 2 can reach values up to 3 × 10 3 .

Separation of SO2 and NO2 with the Zeolite Membrane: Molecular Simulation Insights into the Advantageous NO2 Dimerization Effect

“…30 S. Thompo et al also studied adsorption separation of NO 2 / N 2 O 4 from N 2 on the carbon nanotube by considering NO 2 / N 2 O 4 equilibrium within the pores and within the gas phase using RxMC simulation and adsorption by Gibbs-Ensemble MC. 47 The consistent results indicate that the current multicomponent adsorption equilibria of NO 2 and N 2 O 4 between adsorbed phases and their constant gas phases determined by given total pressure, mixture composition, and NO 2 −N 2 O 4 chemical reaction equilibria under fixed temperatures and pressures is reasonable. For the gas mixture in this work, p NO 2 and p N 2 O 4 can be obtained using their binary equilibrium equation (Section S1) with fixed (p NO 2 + p N 2 O 4 =5% total pressure) based on the ideal gas assumption at the very low pressure and the fact that NO 2 and N 2 O 4 would not react with SO 2 or N 2 .…”

“…Figure S5 shows the comparisons between adsorption isotherms of N 2 O 4 in five different zeolites (binary equimolar mixture at 298 K) using the methodology of this work and conventional reactive Monte Carlo (RxMC) simulation . S. Thompo et al also studied adsorption separation of NO 2 /N 2 O 4 from N 2 on the carbon nanotube by considering NO 2 /N 2 O 4 equilibrium within the pores and within the gas phase using RxMC simulation and adsorption by Gibbs-Ensemble MC . The consistent results indicate that the current multicomponent adsorption equilibria of NO 2 and N 2 O 4 between adsorbed phases and their constant gas phases determined by given total pressure, mixture composition, and NO 2 –N 2 O 4 chemical reaction equilibria under fixed temperatures and pressures is reasonable.…”