Solid Adsorbents for Low-Temperature CO2 Capture with Low-Energy Penalties Leading to More Effective Integrated Solutions for Power Generation and Industrial Processes

Abstract

CO 2 capture represents the key technology for CO 2 reduction within the framework of CO 2 capture, utilization, and storage (CCUS). In fact, the implementation of CO 2 capture extends far beyond CCUS since it will link the CO 2 emission and recycling sectors, and when renewables are used to provide necessary energy input, CO 2 capture would enable a profitable zero-or even negative-emitting and integrated energy-chemical solution. To this end, highly efficient CO 2 capture technologies are needed, and adsorption using solid adsorbents has the potential to be one of the ideal options. Currently, the greatest challenge in this area is the development of adsorbents with high performance that balances a range of optimization-needed factors, those including costs, efficiency, and engineering feasibility. In this review, recent advances on the development of carbon-based and immobilized organic amines-based CO 2 adsorbents are summarized, the selection of these particular categories of materials is because they are among the most developed low-temperature (<100°C) CO 2 adsorbents up to date, which showed important potential for practical deployment at pilot-scale in the near future. Preparation protocols, adsorption behaviors as well as pros and cons of each type of the adsorbents are presented, it was concluded that encouraging results have been achieved already, however, the development of more effective adsorbents for CO 2 capture remains challenging and further innovations in the design and synthesis of adsorbents are needed.Keywords: CCUS, CO 2 capture, adsorption, energy, material science INTRODUCTION CO 2 CAPTURE AND AN INTEGRATED ENERGY-CHEMICAL SOLUTIONThe atmospheric CO 2 concentration now exceeds 400 ppm (CO2Now.org, 2014), and its continuous increase is believed to be the major factor leading to global warming and climatic change (Crowley, 2000;Held and Soden, 2000;Patz et al., 2005). Kaya et al. and Hoffert et al. have quantified net CO 2 emissions in terms of population, economic activity, and energy-related factors using Eq. 1 (Kaya, 1995;Hoffert et al., 1998).where C is the net CO 2 emission, P is population, GDP is the gross domestic product that is used here as an indicator of economyrelated factor, and E is energy production. Therefore, GDP/P is the Per capita GDP, and E/GDP can be regarded as the energy intensity during production that is closely related to the efficiency of energy utilization. The last term, C/E, represents the carbon intensity during energy production. As for the development of the human society and life quality, it is improper to limit population and production, which means there is no solution to CO 2 reduction from the first and second term in Eq. 1. On the other hand, increase in the energy production/utilization efficiency and control of the carbon footprint during energy processes are the major strategies for CO 2 sequestration (third and fourth term in Eq. 1). The complete decarbonization of energy is believed to be the ultimate solution for the long-term sustainability, ...

A Review of State‐of‐the‐Art Microfluidic Technologies for Environmental Applications: Detection and Remediation

“…Carbon capture and storage (CCS) has widely been regarded as an indispensable pathway in containing atmospheric CO 2 without compromising energy security. Conventional techniques for large‐scale carbon reduction include chemical and physical absorption, adsorption with solid sorbents, selective separation with membrane systems, and also cryogenic separation . Amine scrubbing is deemed the most mature technology for carbon removal from processed gases yet the major drawback is its prohibitive energy penalty.…”

“…Many other alternative capture technologies are still under intensive development and the majority of them are yet to be fully demonstrated and commercialized. Among the many capture technologies currently under development, adsorption‐based carbon capture has been recognized as being a viable alternative, both technically or economically, and various types of solid sorbents have been investigated, including supported amines, supported carbonates, zeolites, and different classes of microporous organic polymers (MOPs) . MOPs have shown good thermal and chemical stability, better performances, and selectivity toward various gases, and are promising in that they show great potential in synthetic diversification.…”

Emerging materials for lowering atmospheric carbon

“…Activated carbon has high surface areas (typically >1000 m 2 /g), low chemical activity, and the ability to adsorb molecules from gas and liquid phases due to its highly developed porosity ranging from micropores (<2 nm) to mesopores (2-50 nm) and macropores (>50 nm) (Rodriguez-Reinoso, 2006;Sun et al 2015). In activated carbon, more than 90% of the adsorption occurs in the micropores; however meso-and macropores aid the overall performance of the material, because they provide facile pathways to the molecules absorbed into the micropores (Rodriguez-Reinoso, 2006;Sun et al 2015). Recent reports have shown that narrow microporosity (<0.7 nm) is the key factor for adsorbing CO 2 at low pressures (~ 1 bar) and…”

“…suggest that adsorption occurs via a -pore-filling‖ mechanism (Martin et al, 2011;). Carbon based adsorbents for CO 2 capture are attractive due to their low cost, fast kinetics, ultra-high stability, ease of regeneration, hydrophobicity, and adsorption capacities at elevated (partial) pressures that are appropriate for CO 2 capture and separation from power plant sources (Sun et al, 2015;Choi et al 2009;Shafeeyan et al, 2011). However, the ability to capture CO 2 directly from the atmosphere require more selective and higher CO 2 binding affinities.…”

Polyacrylonitrile Nanoparticle‐Derived Hierarchical Structure for CO2 Capture

“…In addition to the positive effect of nitrogen in CO 2 capture, the importance of suitable pore size has also been reported . Pore sizes below 0.7 nm have been shown to have a tremendous effect on the final CO 2 uptake .…”