Synthetic silico-metallic mineral particles SSMMP: A new option for CO2 capture and CO2/N2 separation from post-combustion technology

A new class of solid adsorbents based on pristine and ionic liquid (IL) functionalized synthetic silico-metallic mineral particles (SSMMP) for CO2 capture and CO2/N2 separation are presented. Pristine particles were submitted to hydrothermal treatment producing synthetic talc. Samples were characterized by thermal analyses (TGA), specific surface area measurements (BET), infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction(XRD), NMR spectroscopy, and scanning electron microscopy (SEM). Values for specific surface areas varied from 5 m2/g for a sample with high IL content to 354 m2/g for pristine SSMMP. Samples presented distinct morphology as well as sorption capacities. IL and its increased concentration in the samples negatively influenced CO2 sorption capacity but played an essential role in CO2/N2 selectivity. The best results were obtained from CO2 sorption values for SSMMP-M1 without IL of 2.07 mmol CO2/g at 1 bar and 4.93 mmol CO2/g at 30 bar. In addition, a selectivity of 16.94 for the CO2/N2 mixture was achieved for SSMMP-5%-Im(nBu)-I sample. SSMMP particles are easy to obtain with low-cost starting materials used in the low energy and CO2-free emission synthesis process. The sorption/desorption cycles proved the stability for both pristine and IL functionalized samples.