Post-combustion CO 2 capture from the flue gas is one of the key technology options to reduce greenhouse gases, because this can be potentially retrofitted to the existing fleet of coal-fired power stations. Adsorption processes using solid sorbents capable of capturing CO 2 from flue gas streams have shown many potential advantages, compared to other conventional CO 2 capture using aqueous amine solvents. In view of this, in the past few years, several research groups have been involved in the development of new solid sorbents for CO 2 capture from flue gas with superior performance and desired economics. A variety of promising sorbents such as activated carbonaceous materials, microporous/mesoporous silica or zeolites, carbonates, and polymeric resins loaded with or without nitrogen functionality for the removal of CO 2 from the flue gas streams have been reviewed. Different methods of impregnating functional groups, including grafting techniques and modifying the support materials, have been discussed to enhance the performance of the sorbents. The performance characteristics of the solid sorbents are assessed in terms of various desired attributes, such as their equilibrium adsorption capacity, selectivity, regeneration, multicycle durability, and adsorption/ desorption kinetics. The potential of metal-organic frameworks (MOFs) is also recognized to determine whether these novel materials provide better CO 2 adsorption capacity under low CO 2 partial pressure. A comprehensive critical review and analysis of the literature on this subject has been carried out to update the recent progress in this arena. A comparison of different solid sorbents at different stages is made. It also includes a brief review on techno-economic analysis and design aspects of sorbent bed contactor configuration. Finally, a few recommendations have been proposed for further research efforts to progress post-combustion carbon capture.

A hydrophobic CO 2 physisorbent Most materials for carbon dioxide (CO 2 ) capture of fossil fuel combustion, such as amines, rely on strong chemisorption interactions that are highly selective but can incur a large energy penalty to release CO 2 . Lin et al . show that a zinc-based metal organic framework material can physisorb CO 2 and incurs a lower regeneration penalty. Its binding site at the center of the pores precludes the formation of hydrogen-bonding networks between water molecules. This durable material can preferentially adsorb CO2 at 40% relative humidity and maintains its performance under flue gas conditions of 150°C. —PDS

In this work, an experimental and theoretical investigation was conducted on the adsorptive removal of CO 2 onto tetraethylenepentamine (TEPA) functionalized mesoporous SBA-15. The functionalization of SBA-15 silica with TEPA was achieved using a conventional wet impregnation technique. The structural properties of the mesoporous silica sorbents were characterized by nitrogen adsorption/desorption, SAXS, SEM, TEM, and FTIR techniques. The adsorption of CO 2 on the amine-impregnated sorbent was measured by thermogravimetric method over a CO 2 partial pressure range of 10−100 kPa and a temperature range of 30−100 °C under atmospheric pressure. The effects on CO 2 adsorption capacity of temperature, partial pressure of CO 2 , amine loading, and moisture were evaluated. All the impregnated SBA-15 sorbents showed reversible CO 2 adsorption behaviors with fast adsorption kinetics. The CO 2 adsorption capacity measured at different temperatures suggests that the optimal adsorption temperature is 75 °C. The CO 2 uptake of the amine-impregnated sorbent increased significantly in the presence of moisture. SBA-15 containing 60 wt % TEPA showed the highest CO 2 adsorption capacity of 5.22 mmol/g in pure and humid CO 2 at 75 °C. Temperature swing adsorption/desorption cycles were also explored using simulated flue gas in both dry and humid conditions, and it was found that CO 2 uptake after ten cycles was within 90% of CO 2 uptake of the first cycle. Different adsorption kinetic models have also been investigated to analyze the experimental data of CO 2 uptake. The model was validated with the experimental results of isothermal adsorption measurements of CO 2 on SBA-15/TEPA. It has been found that Fractional Order kinetic model (Chem. Eng. J. 2011, 173, 72) is very good over the entire adsorption region of the study with a maximum average absolute deviation between experimental CO 2 uptake and that calculated from the model of about 2.42%.

Steam regeneration of polyethylenimine (PEI)-impregnated commercial grade silica was investigated in a packed bed reactor. Adsorption was performed at 75 °C under 10% CO2/N2, and desorption was carried out under steam at 110 °C for 20 consecutive cycles. CO2 adsorption capacity was found to decrease by 9 mol % over the period of 20 cycles. No evident signs of sorbent degradation due to PEI leaching or changes in surface morphology and amine functionalities were observed upon characterization of the sorbent after the cyclic study. Most of the loss in adsorption capacity was associated with thermal degradation of the sorbent during drying under N2 after steam stripping at 110 °C. The desorption kinetics during steam stripping was found to be much faster than during N2 stripping. Over 80% of the total CO2 was released within the first 3 min of steam injection into the reactor. A separate packed bed study was conducted to investigate the influence of moisture content (5.3–14.7 vol %) in flue gas on the CO2 adsorption capacity of PEI-impregnated silica. The presence of moisture had a positive impact on CO2 uptake of the sorbent; a 4–9 mol % increase in CO2 uptake was observed in comparison to the adsorption under dry conditions. However, the presence of moisture increased the heat of regeneration of the sorbent significantly. It was calculated that the energy demand increased approximately 2-fold on introduction of 14.7% moisture compared to that of dry flue gas.

To energy-efficiently offset our carbon footprint, we developed a layered H-SOFC with multiple-twinned Ni0.8Co0.2 nanoparticles, achieving three milestones: CO2 utilization, electricity generation and syngas production.

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Cathodes of porous YSZ supports infiltrated with Nd2NiO4+δ nanoparticles are offered as an alternative solution for IT-SOFC cathodes, presenting maximum power densities of 0.4 W cm−2 at 600 °C.

Directly utilizing hydrocarbon fuels, particularly methane, is advantageous yet challenging in high-performance protonic ceramic fuel cells. In this work, this technological hurdle is well addressed by selective deposition of secondary electrocatalysts within the porous Ni-cermet anode. This novel strategy sheds light on the development of multifunctional porous structures for energy and catalysis applications.