Ferdi Karadas

High capacity carbon dioxide adsorption by inexpensive covalent organic polymers

Efficient CO2 scrubbing without a significant energy penalty remains an outstanding challenge for the fossil fuel-burning industry where aqueous amine solutions are still widely used. Porous materials have long been evaluated for next generation CO2 adsorbents. Porous polymers, robust and inexpensive, show promise as feasible materials for the capture of CO2 from warm exhaust fumes. We report the syntheses of porous covalent organic polymers (COPs) with CO2 adsorption capacities of up to 5616 mg g−1 (measured at high pressures, i.e. 200 bar) and industrially relevant temperatures (as warm as 65 °C). COPs are stable in boiling water for at least one week and near infinite CO2/H2 selectivity is observed.

Amidoximes: promising candidates for CO2 capture

Monoethanolamine (MEA) dominates power plant carbon dioxide (CO2) scrubbing processes, though with major disadvantages such as a 8–35% energy penalty. Here we report that structurally comparable amidoximes are promising CO2 capture agents based on RIMP2 electronic structure calculations. This was experimentally verified by the synthesis and testing of representative amidoximes for capture efficiencies at pressures as high as 180 bar. Acetamidoxime, which has the highest percent amidoxime functionality showed the highest CO2 capacity (2.71 mmol g−1) when compared to terephthalamidoxime (two amidoximes per molecule) and tetraquinoamidoxime (four amidoximes per molecule). Polyamidoxime surpassed activated charcoal Norit RB3 for CO2 capture per unit surface area. Adsorption isotherms exhibit Type IV behavior and acetamidoxime found to increase CO2 capture with temperature, a less observed anomaly. Porous amidoximes are proposed as valuable alternatives to MEA.

CO2 Adsorption Studies on Hydroxy Metal Carbonates M(CO3)x(OH)y (M = Zn, Zn–Mg, Mg, Mg–Cu, Cu, Ni, and Pb) at High Pressures up to 175 bar

Carbon dioxide (CO(2)) adsorption capacities of several hydroxy metal carbonates have been studied using the state-of-the-art Rubotherm sorption apparatus to obtain adsorption and desorption isotherms of these compounds up to 175 bar. The carbonate compounds were prepared by simply reacting a carbonate (CO(3)(2-)) solution with solutions of Zn(2+), Zn(2+)/Mg(2+), Mg(2+), Cu(2+)/Mg(2+), Cu(2+), Pb(2+), and Ni(2+) metal ions, resulting in hydroxyzincite, hydromagnesite, mcguinnessite, malachite, nullaginite, and hydrocerussite, respectively. Mineral compositions are calculated by using a combination of powder XRD, TGA, FTIR, and ICP-OES analysis. Adsorption capacities of hydroxy nickel carbonate compound observed from Rubotherm magnetic suspension sorption apparatus has shown highest performance among the other components that were investigated in this work (1.72 mmol CO(2)/g adsorbent at 175 bar and 316 K).

Amidoxime porous polymers for CO2 capture

CO2 capture from fossil fuel based electricity generation remains costly since new power plants with monoethanol amine (MEA) as the scrubbing agent are under construction. Amidoximes are known to mimic MEA, and porous polymers with amidoximes could offer a sustainable solution to carbon capture. Here we report the first amidoxime porous polymers (APPs) where aromatic polyamides (aramids) having amidoxime pendant groups were synthesized through low temperature condensation of 4,4′-oxydianiline (ODA) and p-phenylene diamine (p-PDA) with a new type of nitrile-bearing aromatic diacid chloride. The nitrile pendant groups of the polyamides were converted to an amidoxime functionality by a rapid hydroxylamine addition (APP-1 and APP-2). The CO2 adsorption capacities of these polyamides were measured at low pressure (1 bar) and two different temperatures (273 and 298 K) and high pressure (up to 225 bar – the highest measuring pressure to date) at 318 K. The low pressure CO2 uptake of APP-1 was found to be 0.32 mmol g−1 compared with APP-2 (0.07 mmol g−1) at 273 K, whereas at high pressure they showed a substantial increase in CO2 adsorption capacity exhibiting 24.69 and 11.67 mmol g−1 for APP-1 and APP-2 respectively. Both aramids were found to be solution processable, enabling membrane applications.

High-pressure CO2 Adsorption on Conventional Hydroxyl Metal Carbonates

Abstract Carbon dioxide (CO2) adsorption capacities of several hydroxy metal carbonates have been studied using the state-of-the-art RubothermR Sorption apparatus to obtain adsorption and desorption isotherms of these compounds up to 175 bar. The carbonate compounds were prepared by simply reacting a carbonate (CO32−) solution with solutions of Zn2+, Zn2+/Mg2+, Mg2+, Cu2+/Mg2+, Cu2+, Pb2+, and Ni2+ metal ions resulting in hydroxyzincite, hydromagnesite, mcguinnessite, malachite, nullaginite, and hydrocerussite, respectively. Mineral compositions are calculated by using a combination of powder XRD, TGA, FTIR, and ICP-OES analysis. Adsorption capacity of hydroxy nickel carbonate compound obtained from RubothermR Magnetic Suspension Sorption apparatus has shown highest performance among the other components that were investigated in this work (1.72 mmole CO2/gram adsorbent at 175 bar and 316 K).

Preparation, characterization and investigation of CO2 adsorption behavior of zinc-magnesium carbonate compounds

AbstractThe capture of CO2 from flue gases derived from fossil fuelled power plants and the absorption of CO2 from natural gas sweetening processes are two relevant industrial problems closely related with very important environmental, economical and technological problems that need to be solved. Porous inorganic compounds have received attention in recent years due to their possible applications in the carbon dioxide capture and storage field. In this work, we prepared new metal carbonates by reacting CO32- solution with solutions of Zn2+-Mg2+ metal ions in different stoichiometric ratios. The samples were characterized with powder x-ray diffraction analysis (PXRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Furthermore, these samples were measured with a Rubotherm magnetic suspension balance to investigate their CO2 adsorption behavior and performance.