Exceptionally High CO2 Capturing Capacity of Porous Organic Polymers

Pre-combustion flue gas capture has been emerged as an efficient alternative to circumvent the costly procedures of materials regeneration utilized by the energy industry for CO2 capture and separation. Stability of the porous structure and repeated use at high pressure and high temperature are among the essential requirements for the efficient materials to be used for industrial level CO2 separation. Herein we report the CO2 adsorption-desorption performance of nanoporous covalent organic polymers (COPs), which can operate efficiently and repeatedly at elevated pressure of 200 bars and above. Since, pre-combustion capture also requires removal of hydrogen along with CO2; therefore, nanoporous COP was also tested for hydrogen removal at high pressure. COP material prepared with simple technique from building block monomers of cyanuric chloride and linked with 1,3-bis(4-piperidinyl)propane has enough surface area and pore volume which makes the material capable to store large quantity of syngas at high temperature and pressure. Results indicated that the newly synthesized COP material can adsorbed exceptionally large quantity of CO2 and very little hydrogen at 200 bars and 35°C. Additionally, the adsorption isotherm was exactly matched with the desorption isotherm, suggesting the material has excellent adsorption-desorption characteristics. Similarly, the material has shown very stable performance when used repeatedly and alternatively for CO2 and hydrogen after regeneration at 50°C. The capturing performance of material was also investigated for other gases like methane and nitrogen at various pressures and temperatures. Experimental results revealed that COP material has exceptional CO2 adsorption efficiency, very good selectivity, and strong stability and can be manufacture with simple techniques. Lastly, material is economically attractive when it is compared with the commercially available materials and has exceptional performance contrary to activated carbon, metal organic frame work and monoethanole amine.qscienc

Investigation of Ester- and Amide-Linker-Based Porous Organic Polymers for Carbon Dioxide Capture and Separation at Wide Temperatures and Pressures

Organic compounds, such as covalent organic framework, metal–organic frameworks, and covalent organic polymers have been under investigation to replace the well-known amine-based solvent sorption technology of CO2 and introduce the most efficient and economical material for CO2 capture and storage. Various organic polymers having different function groups have been under investigation both for low and high pressure CO2 capture. However, search for a promising material to overcome the issues of lower selectivity, less capturing capacity, lower mass transfer coefficient and instability in materials performance at high pressure and various temperatures is still ongoing process. Herein, we report synthesis of six covalent organic polymers (COPs) and their CO2, N2, and CH4 adsorption performances at low and high pressures up to 200 bar. All the presented COPs materials were characterized by using elemental analysis method, Fourier transform infrared spectroscopy (FTIR) and solid state nuclear magnetic resonance (NMR) spectroscopy techniques. Physical properties of the materials such as surface areas, pore volume and pore size were determined through BET analysis at 77 K. All the materials were tested for CO2, CH4, and N2 adsorption using state of the art equipment, magnetic suspension balance (MSB). Results indicated that, amide based material i.e. COP-33 has the largest pore volume of 0.2 cm2/g which can capture up to the maximum of 1.44 mmol/g CO2 at room temperature and at pressure of 10 bar. However, at higher pressure of 200 bar and 308 K ester-based compound, that is, COP-35 adsorb as large as 144 mmol/g, which is the largest gas capturing capacity of any COPs material obtained so far. Importantly, single gas measurement based selectivity of COP-33 was comparatively better than all other COPs materials at all condition. Nevertheless, overall performance of COP-35 rate of adsorption and heat of adsorption has indicated that this material can be considered for further exploration as efficient and cheaply available solid sorbent material for CO2 capture and separation.Qatar National Research Fund, National Priorities Research Program grant (NPRP 5-499-1-088)

Advanced Polymeric Materials with Exceptional Carbon Dioxide Capture Capacities

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.qscienc