Ionic degradation inhibitors and kinetic models for CO2 capture with aqueous monoethanolamine

The degradation of monoethanolamine (MEA) solution was to be around 10% of the total cost of carbon dioxide (CO2) capture, thus, it is critically important to develop high efficient inhibitors. In this study, two novel ionic degradation inhibitors, monoethanolamine tartrate (MTA) and mercapto-ethylamine tartrate (HTA) were synthesized. The results indicated that the inhibitive extent is in the order: MTA > KNaC4H4O6 > HTA > Na2SO3. The degradation kinetics of MEA solution with MTA was studied under conditions typical of the CO2 absorption process considering key factors, such as degradation temperature and aqueous phase concentrations of MEA, O2, SO2, CO2, MTA and Fe2+. The degradation rate increases with the increases of temperature and concentrations of MEA, O2 and SO2, whereas decreases with increasing concentrations of CO2 and ionic degradation inhibitor. The degradation kinetic model of MEA solution which firstly introduces the influences of the components of ionic degradation inhibitor and Fe2+ was proposed by fitting the experimental data.