The urgency of the development of CO ₂ capture from ambient air

Abstract

CO 2 capture and storage (CCS) has the potential to develop into an important tool to address climate change. Given society’s present reliance on fossil fuels, widespread adoption of CCS appears indispensable for meeting stringent climate targets. We argue that for conventional CCS to become a successful climate mitigation technology—which by necessity has to operate on a large scale—it may need to be complemented with air capture, removing CO 2 directly from the atmosphere. Air capture of CO 2 could act as insurance against CO 2 leaking from storage and furthermore may provide an option for dealing with emissions from mobile dispersed sources such as automobiles and airplanes.

Direct air capture of CO2 and climate stabilization: A model based assessment

“…APS provides estimates based on today's technology. Lackner et al(2012) have recently argued that the cost of DAC could well come down to the level that would make it economically interesting, as many other new technologies do when R&D and learning-by-doing could continue to drive the cost down. However, given the uncertainty prospects of technology evolution in this sector, in this paper we take a conservative view and assume investments costs to remain constant in time.…”

A Fine-Tuned Fluorinated MOF Addresses the Needs for Trace CO2 Removal and Air Capture Using Physisorption

“…Inopportunely, the worldwide energy needs have doubled the fossil fuel consumption in the last two decades, [1][2][3][4][5][6][7][8][9][10][11] as a result of the eminent economic growth and the enhanced quality of living in emerging countries, and thus provoking the manifest and amplified global carbon dioxide emission. The foreseen deployment of a relatively cleaner alternative energy sources, e.g.…”

“…Explicitly, point-source carbon capture and storage (CCS) can be regarded as a plausible solution sanctioning the sustainable use of fossil fuels in power, steel and cement production plants, while direct air capture (DAC) can address and remediate the CO 2 emissions from mobile-sources such as automobiles and airplanes. [1][2][3][4][5][6][7][8][9][10][11] Markedly, the DAC offers a great prospective to remotely capture the emitted CO 2 at a different distant location and time. It is to note that the CO 2 capture from air using the chemical adsorption technology has been deployed, for over seven decades, to maintain a safe level of CO 2 in confined spaces such as space shuttles and submarines, where access to fresh air is limited.…”

“…12,13 Nevertheless, the CO 2 concentrations and the associated CO 2 quantities to the DAC (400 ppm CO 2 , worldwide average of 54 kg/person/day) and to the point-source CCS (7-15% CO 2 , worldwide average of 38 kg/person/day) entail a relatively larger scale footprint and/or an excessive energy penalty than the requisites for the CO 2 capture in confined spaces (1-5 % CO 2 and 1 kg/person/day). [1][2][3][4][5][6][7][8][9][10][11] Perceptibly, the cost associated to the CO 2 capture in confined spaces is not a disturbing concern, as the compulsory objective is the effective removal of CO 2 and the subsequent procurement of the indispensable clean air. Noticeably, the low CO 2 concentration in air (400 ppm) and the compulsory low CO 2 level in confined spaces (< 0.5 %) position chemical adsorbents, such as aqueous alkylamine solutions and lithium hydroxide (LiOH) (80-120 kJ/mol), as the conventional benchmark materials, with a high CO 2 -selectivity even in the presence of water vapor, for the carbon capture in diluted CO 2 concentrations 8 Nevertheless, largescale widespread of the chemically driven separation approach is hampered by the prohibitive high-energy requirement for the CO 2 desorption/regeneration process.…”

“…22,[25][26][27][28] Nevertheless, only a limited number of functionalized MOFs, affording the CO 2 -chemisorption, showed promise for DAC and low-concentration CO 2 capture from confined spaces (<0.5 %). 22,26 Outwardly, it was intuited that chemisorption based sorbents are the foremost option for traces CO 2 capture, 8 and atypically put forward that physical adsorbents are prone to be ineffective for carbon capture at the low CO 2 concentration of 400 ppm due to their plausibly weak interactions with the adsorbed CO 2 molecules. Contradictorily to this uncorroborated assumption, we recently published a series of CO 2 -selective MOF adsorbents, namely MSiF 6 (pyrazine) 2 ·2H 2 O (referred to as SIFSIX-3-M where M = Ni, Cu and Zn), showing excellent CO 2 selectivity and uptake at relatively low CO 2 concentrations using solely the physisorption mechanism, 17,30,31 and in some instances outclassing some of the amine grafted chemical sorbents.…”