Flue-Gas Carbon Capture on Carbonaceous Sorbents:  Toward a Low-Cost Multifunctional Carbon Filter for “Green” Energy Producers

Abstract

A low-pressure Carbon Filter Process (patent pending) is proposed to capture carbon dioxide (CO 2 ) from flue gas. This filter is filled with a low-cost carbonaceous sorbent, such as activated carbon or charcoal, which has a high affinity (and, hence, high capacity) to CO 2 but not to nitrogen (N 2 ). This, in turn, leads to a high CO 2 /N 2 selectivity, especially at low pressures. The Carbon Filter Process proposed in this work can recover at least 90% of flue-gas CO 2 of 90%+ purity at a fraction of the cost normally associated with the conventional amine absorption process. The Carbon Filter Process requires neither expensive materials nor flue-gas compression or refrigeration, and it is easy to heat integrate with an existing or grassroots power plant without affecting the cost of the produced electricity too much. An abundant supply of low-cost CO 2 from electricity producers is good news for enhanced oil recovery (EOR) and enhanced coal-bed methane recovery (ECBMR) operators, because it will lead to higher oil and gas recovery rates in an environmentally sensitive manner. A CO 2 -rich mixture that contains some nitrogen is much less expensive to separate from flue-gas than pure CO 2 ; therefore, mixed CO 2 /N 2 -EOR and CO 2 /N 2 -ECBMR methods are proposed to maximize the overall carbon capture and utilization efficiency.

Feasibility of CO2 adsorption by solid adsorbents: a review on low-temperature systems

“…For instance, the CO 2 heat of adsorption on zeolite is substantial enough to cause the rise of adsorption temperature as much as 50°C. Thus, it has been reported that the CO 2 heat of adsorption on zeolite is *10 times higher than that on activated carbon at the same temperature and pressure (Radosz et al 2008;Zhao et al 2012). Some of the studies revealed the same isosteric heat of CO 2 adsorption for MOPs and activated carbons, reflecting the structural similarities between the two adsorbent materials.…”

Post-combustion CO2 capture with a commercial activated carbon: Comparison of different regeneration strategies

“…Zeolite 13X is by far the adsorbent most extensively studied in CO 2 separation processes, due to its high selectivity to CO 2 [21]. However, several studies have also appeared in the literature dealing with activated carbons [4,22]. Activated carbons present important advantages over zeolites, such as hydrophobicity, significant lower cost, and lower energy requirements to carry out their regeneration (the isosteric heat of adsorption of CO 2 over activated carbons is ca.…”

“…Ho et al estimated that using zeolite 13X, a capture cost of US$ 51 per ton of CO 2 avoided could be attained, including the cost of product compression (purity of 48 %), with an additional capital investment for capture of US$ 1300 per kW [3]. Radosz et al estimated a total cost of compressed-pipeline ready CO 2 of US$ 27 per ton for a power plant integrated TSA process, and of US$ 44 per ton for a VSA process, using an activated carbon as adsorbent [4].…”

“…However, this technology presents a series of drawbacks, such as high energy requirement associated to sorbent regeneration, amine losses due to evaporation, corrosion problems, thermal and chemical degradation of the amines in the presence of oxygen, etc. Adsorption is a separation technology with potential to reduce the cost of post-combustion capture compared to amine scrubbing [3][4][5]. Two main adsorption technologies are being considered: pressure swing adsorption (PSA) and temperature swing adsorption (TSA).…”

Sustainable biomass-based carbon adsorbents for post-combustion CO2 capture

“…+34 985 11 90 90; Fax: +34 985 29 76 62 e-mail address: frubiera@incar.csic.es regenerate the diluted amine solvent: a parasitic loss of 30% of the net power is expected from the use of MEA processes [3]. Adsorption is a separation technology with the potential to reduce the energy penalty of the capture step compared to amine scrubbing [4][5][6][7][8]. The main advantages of adsorption processes over amine scrubbing are the lower energy requirements and the higher capacity on a volume basis [9].…”