Thermokinetic properties and performance evaluation of benzylamine-based solvents for CO2 capture

• New CO2 capture solvent based on benzylamine.
• Fast kinetics, high stability and low viscosity, corrosion and heat capacity.
• When formulated with another amine yields reduced energy requirement.

Carbon dioxide (CO2) post combustion capture and storage is the most mature technology option for the mitigation of CO2 emissions from fossil fuel electricity generation. Typically CO2 separation at low pressure is achieved by reactive chemical absorption using aqueous amines. In this work benzylamine (BZA) has been assessed in terms of the chemical and physical properties relevant for its application as an aqueous amine CO2 absorbent. BZA was found to have similar reaction kinetics with CO2 to monoethanolamine (MEA) (kcarb = 7600 M−1 s−1 at 35 °C and Ea = 38 kJ mol−1) and similar carbamate stability but with a ∼40% larger enthalpy of protonation. It was also found to be less corrosive and have lower viscosity and heat capacity. Significant performance gains relative to MEA 30 wt% were predicted by using BZA in a formulation with either MEA or 2-amino-2-methyl-1-proponal (AMP) with predicted reductions in reboiler duty up to 13%, improvements in mass transfer up to 20% and low corrosion potential.