(506c) Silica Supported Poly(Propylene Guanidine) for CO2 Capture in Simulated Flue Gas and Ambient Air

Guanidine-based compounds have been studied extensively in CO₂ capture applications in the past, due to their highly basic nature. In this work, the synthesis of poly(propylene guanidine) (PPG) is described via the polycondensation of propylene diamine and guanidine hydrochloride. It is demonstrated that the structure of synthesized PPG is composed of primarily ring structures, with the average molecular weight under 1000 Da. The synthesized polymer is impregnated into a mesoporous silica support, SBA-15, and the CO₂ capture performance of the sorbent is measured under simulated flue gas conditions and simulated ambient air conditions. It is found that SBA-15 supported PPG shows a maximum capacity of 1.1 mmol/g using 10% CO₂, and 0.61 mmol/g using 400 ppm CO₂ at 30°C with a sorbent with 50 wt% polymer loading. Meanwhile, SBA-15 supported PEI shows maximum capacity of 1.3 mmol/g and 1.1 mmol/g under similar conditions with 48 wt% polymer loading. Although its performance was lower than PEI, a benchmark polymer in the field of CO₂ capture, the first generation PPG sorbent showed good performance as a CO₂ sorbent.