Advanced Polymeric Materials with Exceptional Carbon Dioxide Capture Capacities

Abstract

Carbon dioxide (CO2) emissions resulting from combustion of fossil based fuels increasing the atmospheric CO2 concentration (currently at 393 ppm) is indubitably an alarming environmental issue such as an irreversible increase in the acidity levels of the oceans. In order to manage current CO2 emissions, several technologies exist such as chemical solvent absorption, physical adsorption, cryogenic fractionation, membrane separation, biological fixation as well as the oxi-fuel combustion process. Solvent-based absorption technology, especially amine-based solvents, is still the most widely used technique for CO2 removal in industry. However, it is a known fact that amine based acid gas removal technologies have severe drawbacks to the process such as corrosion, amine recovery and CO2 uptake capacity. Therefore, in an effort to develop the new possibilities on environmentally friendly and effective CO2 capturing materials in clean energy applications, we recently synthesized a new class of polymers with high CO2 adsorption capability termed cyanuric organic polymers (COPs). These compounds do not include metal complexes resulting in a lighter and more stable porous structure that is essential for high CO2 capture capacity at high pressures. High accuracy CO2 adsorption tests were made at pressures up to 200 bars at three isotherms 318 K, 328 K, and 338 K on three COPs called KAIST-1, KAIST-2 and QATAR-1 by using magnetic suspension based sorption apparatus. Moreover, MOF-5 and activated carbon Norit-RB3 were also experimented for comparison purposes since they are well known porous materials used for CO2 adsorption. Our CO2 adsorption studies at 318 K revealed a capacity of 127.60 mmol/g (5616 mg/g) for KAIST-1, 47.41 mmol/g (2086 mg/g) for KAIST-2 and 74.86 mmol/g (3294 mg/g) for QATAR-1. In order to put into perspective, KAIST-1 can hold more than five times what dry ice has in CO2 considering that COPs show modest surface areas. Here we report robust, inexpensive and reproducible synthesis of cyanuric organic polymers (COPs) with CO2 adsorption capacities up to 5616 mg/g. To the best of our knowledge, this is the highest CO2 adsorption capacity to date.