Experimental and Theoretical Investigation of the Reaction Between Co2andcarbon Dioxide Binding Organic Liquids

Abstract

The reaction kinetics of CO2absorption into new carbon dioxide binding organic liquids (CO2BOLs) was com-prehensively studied to evaluate their potential for CO2removal. A stopped- ow apparatus with conductivity detectionwas used to determine the CO2absorption kinetics of novel CO2BOLs composed of DBN (1,5-diazabicyclo[4.3.0]non-5-ene)/1-propanol and TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene)/1-butanol. A modi ed termolecular reaction mechanismfor the reaction of CO2with CO2BOLs was used to calculate the observed pseudo- rst{order rate constant k0(s1)and second-order reaction rate constant k2(m3/kmol.s). Experiments were performed by varying organic base (DBN orTBD) weight percentage in alcohol medium for a temperature range of 288{308 K. It was found that k0increased withincreasing amine concentration and temperature. By comparing using two different CO2BOL systems, it was observedthat the TBD/1-butanol system has faster reaction kinetics than the DBN/1-propanol system. Finally, experimentaland theoretical activation energies of these CO2BOL systems were obtained and compared. Quantum chemical calcula-tions using spin restricted B3LYP and MP2 methods were utilized to reveal the structural and energetic details of thesingle-step termolecular reaction mechanism.