Dramatically increased CO2 concentration from several point sources is perceived to cause severe greenhouse effect towards the serious ongoing global warming with associated climate destabilization, inducing undesirable natural calamities, melting of glaciers, and extreme weather patterns. CO2 capture and utilization (CCU) has received tremendous attention due to its significant role in intensifying global warming. Considering the lack of a timely review on the state-of-the-art progress of promising CCU techniques, developing an appropriate and prompt summary of such advanced techniques with a comprehensive understanding is necessary. Thus, it is imperative to provide a timely review, given the fast growth of sophisticated CO2 capture and utilization materials and their implementation. In this work, we critically summarized and comprehensively reviewed the characteristics and performance of both liquid and solid CO2 adsorbents with possible schemes for the improvement of their CO2 capture ability and advances in CO2 utilization. Their industrial applications in pre- and post-combustion CO2 capture as well as utilization were systematically discussed and compared. With our great effort, this review would be of significant importance for academic researchers for obtaining an overall understanding of the current developments and future trends of CCU. This work is bound to benefit researchers in fields relating to CCU and facilitate the progress of significant breakthroughs in both fundamental research and commercial applications to deliver perspective views for future scientific and industrial advances in CCU.

Industrial carbon dioxide capture and utilization: state of the art and future challenges

Valorization of biomass waste to engineered activated biochar by microwave pyrolysis: Progress, challenges, and future directions

Biomass derived porous carbon for CO2 capture

Four different types of amine-attached MCM-48 silicas were prepared and investigated for CO(2) separation from N(2). Monomeric and polymeric hindered and unhindered amines were attached to the pore surface of the MCM-48 silica and characterized with respect to their CO(2) sorption properties. The pore structures and amino group content in these modified silicas were investigated by XRD, FT-IR, TGA, N(2) adsorption/desorption at 77 K and CHN/Si analysis, which confirmed that in all cases the amino groups were attached to the pore surface of MCM-48 at 1.5-5.2 mmol/g. The N(2) adsorption/desorption analysis showed a considerable decrease of the pore volume and surface area for the MCM-48 silica containing a polymeric amine (e.g., polyethyleneimine). The CO(2) adsorption rates and capacities of the amine-attached MCM-48 samples were studied employing a sorption microbalance. The results obtained indicated that in addition to the concentration of surface-attached amino groups, specific interactions between CO(2) and the surface amino groups, and the resultant pore structure after amine group attachment have a significant impact on CO(2) adsorption properties of these promising adsorbent materials.

Tailoring pore properties of MCM-48 silica for selective adsorption of CO2

Carbon-based functional materials hold the key for solving global challenges in the areas of water scarcity and the energy crisis. Although carbon nanotubes (CNTs) and graphene have shown promising results in various fields of application, their high preparation cost and low production yield still dramatically hinder their wide practical applications. Therefore, there is an urgent call for preparing carbon-based functional materials from low-cost, abundant, and sustainable sources. Recent innovative strategies have been developed to convert various waste materials into valuable carbon-based functional materials. These waste-derived carbon-based functional materials have shown great potential in many applications, especially as sorbents for water remediation and electrodes for energy storage. Here, the research progress in the preparation of waste-derived carbon-based functional materials is summarized, along with their applications in water remediation and energy storage; challenges and future research directions in this emerging research field are also discussed.

Carbon-Based Functional Materials Derived from Waste for Water Remediation and Energy Storage.

Nitrogen-doped porous carbons obtained from coconut shell by urea modification and KOH activation are found to exhibit very high CO2 uptake at 1 bar, almost 5 mmol g–1 at 25 °C and over 7 mmol g–1 at 0 °C, respectively. The high CO2 uptake of the sorbent can be ascribed to its high microporosity and nitrogen content. In addition, these sorbents possess high CO2/N2 selectivity, stable cyclic ability, high initial heat of CO2 adsorption, fast adsorption kinetics, and high dynamic CO2 capture capacity under simulated flue gas conditions. When combined with the low cost of the coconut-shell precursor, these properties make them exceptionally attractive sorbent candidates for CO2 capture.

Enhanced CO2 Capture Capacity of Nitrogen-Doped Biomass-Derived Porous Carbons

This article reports on the synthesis and characterization of porous nitrogen-doped carbons synthesized by carbonization of coconut shell followed by urea modification and K2CO3 activation. The as-synthesized samples were carefully characterized by various techniques. This series of samples demonstrate high CO2 uptake at 1bar, up to 3.71mmol/g at 25°C in addition to 5.12mmol/g at 0°C. Furthermore, these sorbents possess fast CO2 adsorption kinetics, stable reusability, moderate heat of CO2 adsorption, reasonable CO2/N2 selectivity, and high dynamic CO2 capture capacity under simulated flue gas conditions. It is found that, in addition to nitrogen content and narrow micropore volume, the pore size distribution of narrow micropore also plays a major role in determining the CO2 capture capacity under ambient condition. This work is intended to provide useful information and to inspire ways to develop new carbonaceous sorbents for removing CO2 from combustion flue gas.

CO 2 adsorption at nitrogen-doped carbons prepared by K 2 CO 3 activation of urea-modified coconut shell

Nitrogen enriched porous carbons from d-glucose with excellent CO2 capture performance

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.

Efficient CO2 Capture by Porous Carbons Derived from Coconut Shell

In this work, the coconut shell was preoxidized by hydrogen peroxide, before it was treated by the ammoxidation process and potassium hydroxide activation to synthesize nitrogen-doped porous carbons. The resulting sorbents exhibit significantly higher nitrogen content and narrow microporosity than the control sample without H2O2 pretreatment. Consequently, these sorbents are found to demonstrate high carbon dioxide uptake at 1 bar, such as 4.47 mmol g–1 at 25 °C and 6.79 mmol g–1 at 0 °C. In addition, these sorbents possess high CO2/N2 selectivity, stable reusability, high initial heat of CO2 adsorption, and high dynamic CO2 capture capacity under simulated flue gas conditions. These superior CO2 adsorption properties make them highly competitive among all the carbonaceous adsorbents for CO2 capture.

Jie Yang

Papers

Enhanced CO2 Capture Capacity of Nitrogen-Doped Biomass-Derived Porous Carbons

CO 2 adsorption at nitrogen-doped carbons prepared by K 2 CO 3 activation of urea-modified coconut shell

Nitrogen enriched porous carbons from d-glucose with excellent CO2 capture performance

Efficient CO2 Capture by Porous Carbons Derived from Coconut Shell

Role of Hydrogen Peroxide Preoxidizing on CO2 Adsorption of Nitrogen-Doped Carbons Produced from Coconut Shell