Indirect ocean capture of atmospheric CO2: Part I. Prototype of a negative emissions technology

Electrochemical carbon dioxide capture to close the carbon cycle

“…Therefore, to achieve a net zero GHG's emission, in addition to emission reduction, CO 2 capture and utilization is required in the long term. Also, as the long term CO 2 emitters include decentralized emitters, direct capture from CO 2 sinks (e.g., atmosphere and ocean, see Figure (1) is necessary for effectively addressing the anthropogenic CO 2 emissions [8,9]. Figure 1: Schematic of the carbon cycle.…”

“…Nowadays, electrochemical CO 2 capture methods can be applied to all CO 2 containing streams with any concentration. Direct capture from air [35], ocean [8,36] and flue gas [37][38][39] have been reported. Such capture units can be retrofitted as plug-and-play processes, allow small footprints and are geometrically flexible [39,40].…”

An air CO2 capture system based on the passive carbonation of large Ca(OH)2 structures

“…Direct CO 2 capture from air (DAC), combined with permanent CO 2 storage, is one of the negative emission technologies (NETs) that may be needed in the future to limit global warming to 1.5 C. 1,2 The rst conceptual designs of DAC systems were proposed 20 years ago, 3 and research into novel concepts and materials is still continuing today. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] The direct capture of CO 2 from air requires vast contacting surfaces with a great affinity and selectivity towards CO 2 (i.e. through a gas-liquid interface, the internal surface of a solid sorbent or through a membrane).…”

“…20 An entirely different approach is to extract CO 2 from large ows of seawater by electrodialysis, aer which the water is returned to the ocean to reabsorb more CO 2 from the air. 21,22 Some DAC technologies are being tested on increasingly larger scales to assess their technical and economic viability.…”

A direct coupled electrochemical system for capture and conversion of CO2 from oceanwater

“…Since the 1000 largest power plants emit >20% of total global fossil fuel CO 2 emissions 4 , capture of CO 2 from point sources, e.g., flue gas, which often contain higher CO 2 concentrations (10%), has been the focus in the carbon capture and sequestration approach 5,6 . However, to achieve negative emissions in the long term, capture CO 2 directly from air [7][8][9][10][11][12][13][14] or oceanwater [15][16][17][18][19] will likely play a much bigger role [20][21][22][23] . World ocean constitutes the largest carbon sink, absorbing about 40% of anthropogenic CO 2 since the beginning of industrial era [24][25][26] with an effective CO 2 concentration of 2.1 mmol kg −1 , or 0.095 kg m −3 in oceanwater, which is a factor of 120 times larger than in the atmosphere [27][28][29] .…”