Catalyst design for mitigating nitrosamines in CO₂ capture process

Nitrosamines formation during amine based CO₂ capture process has recently gained strong attention due to potential health and environmental concerns. In this paper, catalytic nitrosamine destruction in aqueous amine solutions with amine recovery approach is proposed. An up-flow fixed-bed reactor was designed for laboratory experiments in which a nitrosamine solvent stream along with hydrogen was passed into the reactor over a selected catalyst bed. A number of Pd, Fe and Ni metal catalysts were synthesized based on metal-support interaction and were evaluated toward nitrosamine hydrogenation. The Ni based catalyst was found to possess excellent activity (>95%) toward the destruction of 100mg/L nitrosopyrrolidine in 5mol/kg MEA solution at 120psi hydrogen pressure and 120°C temperature in 4h. Catalyst reusability study was conducted for 15 cycles showed high catalyst activity and stability lasting more than 60h. This catalyst was prepared by incipient-wetness technique and was characterized by SEM, TPR, N₂ adsorption-desorption and XRD to determine its intrinsic structural properties. The catalyst was further studied with several different nitrosamines to prove its utility toward multiple nitrosamines.