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A clear understanding of osmosis’s influence on Darcy flow is essential in the context of petroleum industry. Thus, in this study, osmosis’s influence on Darcy’s law is investigated theoretically b...

In this manuscript, N-doped porous carbonaceous CO2 sorbents were synthesized using biomass waste hazelnut shell as the raw materials, melamine as the nitridation agent, and KOH as the porogen. The...

In this report, porous carbons were made via a facile single-step KOH activation of commercial phenolic resin. Different from the conventional carbonization-activation two-step procedure, this work...

In this work, N-doped porous carbons were synthesized by a one-step sodium amide activation of carbonized lotus leaf at 450–500 °C. The CO2 adsorption properties of the as-synthesized carbonaceous ...

In this work, highly efficient nitrogen-doped porous carbonaceous CO2 sorbents were synthesized by sodium amide activation of petroleum coke at a temperature range of 400–500 °C. The as-obtained so...

In this study, N-enriched porous carbons were prepared by a facile synthesis method at low temperatures ranging from 400 to 500 °C. Sodium amide was used as both activator and nitridation reagent, ...

The synthesis of carbonaceous CO2 adsorbents doped with nitrogen were carried out via a hydrothermal reaction of biomass d-glucose, followed by urea treatment and K2CO3 activation. These carbons display high uptake of CO2 at 1 bar and 25 and 0 °C, up to 3.92 and 6.23 mmol g–1, respectively. Additionally, the as-synthesized materials exhibit superior reusability, high CO2/N2 selectivity, fast CO2 adsorption kinetics, and excellent dynamic capture capacity at the experimental conditions used. The synthetic effect of the nitrogen content and narrow microporosity decide the capture capacity for CO2 at 1 bar and 25 °C for these N-enriched carbonaceous adsorbents. This study provides a viable method to prepare high-performance CO2 carbonaceous sorbents without using caustic KOH. In addition, this work gives further insights into the CO2 adsorption mechanism for nitrogen-doped porous carbon sorbents and, hence, inspires ways to synthesize novel carbonaceous materials for removing CO2 from combustion exhaust gases.

The CO2-capture potential of porous carbons that have been derived from phenolic resin and doped with nitrogen was assessed in this work. Using carbonized commercial phenolic resin as carbon precursors, a series of carbons have been synthesized using urea modification and KOH activation under different conditions. The activation temperature and mass ratio of KOH to precursor affected the CO2 uptake capacity. These phenolic-resin-derived carbons show high CO2 capture capacity, up to 4.61 mmol/g at 25 °C and 7.13 mmol/g at 0 °C under atmospheric pressure. The sample prepared under relatively mild conditions, i.e., activation temperature of 600 °C and mass KOH/precursor of 3, demonstrated the maximum CO2 uptake capacity under ambient conditions. A systematic study shows that the synergetic effects of narrow microporosity and nitrogen content determine the sorbents’ capability to capture CO2. In addition, the pore size and the narrow micropores’ distribution affect the CO2 adsorption capacity of this series o...

Petroleum coke was pretreated by HNO3 before urea modification and KOH activation to synthesize N-doped porous carbons. The as-synthesized samples were carefully characterized by various techniques. This series of samples demonstrate high CO2 uptake at 1 bar up to 4.13 mmol/g at 25 °C and 6.24 mmol/g at 0 °C, respectively. In addition, these sorbents possess high CO2/N2 selectivity, stable reusability, moderate heat of CO2 adsorption, and high dynamic CO2 capture capacity under simulated flue gas conditions. Further comparison shows that sorbents synthesized by HNO3 pretreatment possess higher nitrogen content and narrow microporosity than the control sample without HNO3 pretreatment but a lower CO2 uptake. Additional investigations show that in addition to nitrogen content and narrow micropores, the size of narrow micropores, the narrow micropore size distributions, surface acidity, and the content of specific N and O species on the surface of the N-doped porous carbons also play major roles in determini...

A series of porous carbons for CO2 capture were developed by simple carbonization and KOH activation of coconut shells under very mild conditions. Different techniques such as nitrogen sorption, X-ray diffraction, scanning emission microscopy, and transmission electron microscopy were used to characterize these sorbents. Owing to the high amount of narrow micropores within the carbon framework, the porous carbon prepared at a KOH/precursor ratio of 3 and 600 °C exhibits an enhanced CO2 adsorption capacity of 4.23 and 6.04 mmol/g at 25 and 0 °C under 1 bar, respectively. In addition to the high CO2 uptake, these samples also show fast adsorption kinetics, moderate heat of adsorption, high CO2 over N2 selectivity, excellent recyclability and stability, and superior dynamic CO2 capture capacity. The application of coconut shell as precursors for porous carbons provides a cost-effective way for the development of better adsorbents for CO2 capture.