A comparative energy and costs assessment and optimization for direct air capture technologies

•Three DAC processes were compared on the basis of exergy demand and productivity•Solid sorbent-based perform better than solvent-based processes•CO2 capture costs below 200 $/tCO2 are achievable for all technologies•Adsorption/desorption kinetics H2O affinity strongly affect solid sorbent process Artificial removal CO2 from atmosphere will be pivotal realization CO2-net-zero plans policies. Among few available solutions, direct extraction air—or air (DAC)—features highest potential. Although energy economic expenditure high, is still in its infancy, a large potential exists optimization. To scale up production, different should consistently evaluated, their design operation optimized, needs further development identified. Surprisingly, this missing literature. In study, we discuss optimal performance main technologies, starting publicly unit designs data by using advanced simulation tools. Moreover, identify open challenges that need addressing compute cost as function equipment costs, showing combinations would allow cheaper units. This work provides comparative technical assessment three technologies air: two aqueous-scrubbing one process. We productivity consumption simulations mathematical evaluate range large-scale deployment. show can provide high-purity solid-based has to offer best performance, owing an 1.4–3.7 MJ.kgCO2?1 3.8–10.6 kgCO2.m?3.h?1. Translating into via simple model, capital driver. All have operate $.tonCO2?1 under favorable, yet realistic, reactor costs. The solid-sorbent achieves broader conditions less dependent installation when high mass transfer achieved. Limiting global warming at 2°C, possibly 1.5°C, paramount importance keep results climate change manageable. Paris agreement was signed 2016 designed purpose; however, non-binding unenforceable nature trigger required set actions successful 1.5°C Hence, it not come surprise Intergovernmental Panel Climate Change (IPCC) expects higher target.1Rogelj, J., Shindell, D., Jiang, K., Fifita, S., Forster, P., Ginzburg, V., Handa, C., Kheshgi, H., Kobayashi, Kriegler, E., et al. (2018). Glob. War Med. 1°C. An IPCC Spec. Rep. impacts Warm, above pre-industrial levels Relat. Greenh. gas Emiss. pathways, Context Strength. response Threat, C. Chang, V. Masson-Delmotte, P. Zhai, H.O. Pörtner, D. Roberts, J. Skea, Shukla, A. Pirani, W. Moufouma-Okia, Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, Waterfield, eds.Google Scholar Avoiding overshoot likely require 45% reduction net anthropogenic carbon dioxide (CO2) emissions 2010 2030 reaching zero around 2050.2Allen, M., Dube, O.P., Solecki, W., Aragón-Durand, F., Cramer, Humphreys, Kainuma, Kala, Mahowald, N., Mulugetta, Y., Reduction measures key achieve abatement and, among them, storage (CCS) play important role reducing associated with continuous use fossil fuels. particularly relevant industrial processes, such cement steel production carbon-based chemical production. Not surprisingly, pathways consistent temperature increase dependent, some extent, deployment negative (NETs)2Allen, actively remove atmosphere. NET (DAC), which refers through artificial contactor, engineered, therefore possesses very mitigation potential.3Fuss Lamb W.F. Callaghan M.W. Hilaire Creutzig F. Amann Beringer de Oliveira Garcia Hartmann Khanna al.Negative emissions—Part 2: Costs, potentials side effects.Environ. Res. Lett. 2018; 13: 063002Crossref Scopus (436) Google However, relatively novel early stages commercialization4Nemet G.F. Fuss Minx J.C. Rogers Smith Negative 3: innovation upscaling.Environ. 063003Crossref (144) Scholar; many questions remain answered improvement high. Gas separation pillar engineering, exist used scope. Several mature gas-separation make physical processes; because ultra-diluted concentration air, they good candidates DAC.5Keith D.W. Heidel K. Cherry Capturing atmosphere: rationale considerations.in: Geo-Engineering Environmental Necessity or Pandora's Box? Cambridge University Press, 2010: 107-126Google Also, strong effective air.6Sanz-Pérez E.S. Murdock C.R. Didas S.A. Jones C.W. Direct Ambient Air.Chem. Rev. 2016; 116: 11840-11876Crossref PubMed (904) Currently, there DAC. Zeman Lackner first describe extracted wet scrubbing aqueous alkali hydroxide.7Zeman F.S. K.S. directly atmosphere.World Resour. 2004; 16: 157-172Google system consists cycles. one, sodium potassium hydroxide reacts produce carbonates, soluble water. second cycle, carbonates causticized lime (Ca(OH)2) resulting precipitation CaCO3, then heated 900°C release CO2. concept developed Baciocchi al.,8Baciocchi Storti G. Mazzotti Process requirements air.Chemical Engineering Processing: Intensification. 2006; 45: 1047-1058Crossref (168) who provided conceptual based balances. issues pointed out; most being essentially unavoidable solvent regeneration. Later, report American Physical Society (APS) selected benchmark about $600 per ton captured estimated.9Socolow Desmond Aines Blackstock Bolland O. Kaarsberg Lewis N. Pfeffer Sawyer al.Direct Air Capture Chemicals: A Technology Assessment APS Public Affairs. Society), 2011Google other estimates absorption lower. Due atmosphere, volumes processed amount efficient contact extremely important. where company Carbon focused efforts. By unit, tailor-made applications, Holmes coworkers estimated total contactor alone (that is, neglecting regeneration solvent) could drastically reduced 240 $/tonCO2 assessed APS9Socolow 60 $/tonCO2.10Holmes Keith air–liquid air.Philos. Trans. Soc. Lond. 2012; 370: 4380-4403Crossref (75) contactor11Holmes Nold Walsh Henderson M.A. Ritchie Klavins Singh Outdoor prototype atmospheric dioxide.Energy Procedia. 2013; 37: 6079-6095Crossref (31) units involved regeneration12Keith St Angelo capturing atmosphere.Joule. 1573-1594Abstract Full Text PDF (464) also been tested pilot promising results, prompting plan construction 1 MtonCO2/year plant. major drawbacks related caustic recovery overcome, alternative techniques limited potential.13Sabatino Mehta Grimm Gazzani Gallucci Kramer G.J. van Sint Annaland Evaluation combining bipolar membrane electrodialysis.Ind. Eng. Chem. 2020; 59: 7007-7020Crossref (21) absorption-based described Custelcean al.14Brethomé F.M. Williams N.J. Seipp C.A. Kidder M.K. aqueous-phase crystalline-phase concentrated solar power.Nat. Energy. 553-559Crossref (79) solution amino acids, glycine sarcosine, yielding corresponding bicarbonate salts. acid subsequently recovered crystallization carbonate anions bis-iminoguanidine solid. Finally, crystals decomposed temperatures between 60°C 120°C, thus releasing While lower process, proposed higher.15Custelcean Garrabrant K.A. Agullo Brethomé Martin H.J. CO 2 acids bis-iminoguanidines (BIGs).Ind. 2019; 58: 23338-23346Crossref (18) Indeed, solvents fast but low cyclic capacity. liquid alkanolamines (e.g., monoethanolamine [MEA]) hardly considered applications fact, amine technology post-combustion applied hundreds processes.16Rochelle G.T. Amine capture.Science. 2009; 325: 1652-1654Crossref (2975) basic form, (flue) gases near ambient amines, followed stripping 120°C. Alkanolamines CO2, enough air.17Lackner air.Eur. Phys. Top. 176: 93-106Crossref (297) Despite this, MEA only recently option Barzagli conducted experimental screening amine-based solutions DAC.18Barzagli Giorgi Mani Peruzzini Screening study sorbents air.ACS Sustainable 8: 14013-14021Crossref Aqueous primary amines appeared candidates, 87.3% 24-hour period. Kiani carried out evaluation Aspen Plus, adapting conventional MEA-based air.19Kiani Jiang Feron Techno-economic liquid-based process.Front. Energy 92Crossref (19) 1,690 base case. substantially due column, adopted packed column absorber, cooling tower inspired system, Engineering, reduce absorber 83%. remains requires great amounts low-grade heat regeneration, generally corrosive toxic degrade over time oxidation.20Goeppert Czaun Surya Prakash G.K. Olah G.A. renewable source future: overview atmosphere.Energy Environ. Sci. 5: 7833Crossref (421) These disadvantages partly overcome immobilization supports. exchanging support capacity, regenerate significantly.21Eisenberger P.M. Cohen R.W. Chichilnisky Eisenberger N.M. Chance R.R. Global carbon-negative technology: prospects lower-cost route lower-risk 20: 973-984Crossref degradation corrosion supported problem.22Choi Drese J.H. Adsorbent materials point sources.ChemSusChem. 796-854Crossref (1940) amine-functionalized currently receiving significant attention scientific community6Sanz-Pérez Scholar,23Didas Choi Chaikittisilp Amine-Oxide Hybrid Materials Air.Acc. 2015; 48: 2680-2687Crossref (151) companies them commercial processes. Climeworks porous granulates modified vacuum-pressure swing adsorption (VTSA) cycles.24Gebald Repond Wurzbacher J.A. United States Patent application publication US/0203249 A1.2017Google unloaded material contacted condition; subsequently, evacuated pressure 20–400 mbar 80°C–130°C desorb CO2.25Gebald Tingaut Steinfeld Stability cellulose during temperature-vacuum-swing cycling air.Environ. Technol. 47: 10063-10070Crossref (78) combination vacuum allows capacity limits needed. repressurized cooled down conditions. Thermostat established startups developing commercializing multiple plants already running built.26Fasihi Efimova Breyer plants.J. Clean. Prod. 224: 957-980Crossref (260) addition specific sorbents, differ composition structure, opted contactors. Whereas employs air-filter-like structures,27Gebald Piatkowski Ruesch Organization WO 2014/170184 al.J. World Intellect. Property. uses honeycomb monoliths.28Ping Sakwa-novak Low Cost Technology. International Conference Emissions.Google both cases, VTSA cycle Another class shown performances sorbents29Bhatt Belmabkhout Cadiau Adil Shekhah Shkurenko Barbour L.J. Eddaoudi fine-tuned fluorinated MOF addresses trace physisorption.J. Am. 138: 9301-9307Crossref (223) Scholar,30Shekhah Chen Z. Guillerm Cairns Made-to-order metal-organic frameworks capture.Nat. Commun. 2014; 4228Crossref (359) supports31Darunte L.A. Oetomo A.D. Walton Sholl D.S. functionalized MIL-101(Cr).ACS 4: 5761-5768Crossref (132) Scholar,32McDonald T.M. Lee W.R. Mason Wiers B.M. Hong C.S. Long J.R. flue alkylamine-appended framework mmen-Mg2(dobpdc).J. 134: 7056-7065Crossref (813) (MOFs). MOFs hybrid structures metal nodes linked organic bridges bi- three-dimensional crystalline structures. Their space versatility made various applications; surface area pore characteristics tailor-tuned, sites additional functional groups. On side, commercialization unsolved challenge.33Belmabkhout adsorbents: metal–organic becoming new materials?.Chem. 296: 386-397Crossref (201) considering behavior respect water adsorption. Depending characteristics, requirements. More specifically, obtain quality implement suitable model competitive cooperative adsorption.22Choi Scholar,34Veneman Frigka Zhao Li Kersten Brilman Adsorption sorbents.Int. Greenh Control. 41: 268-275Crossref (69) So far, largely overlooked conclude stand light deployed technological readiness solutions12Keith sorbents.35Wurzbacher Gebald Concurrent temperature-vacuum adsorption/desorption cycle.Environ. 46: 9191-9198Crossref (98) argue regarded equally ready technology. advantages disadvantages. Liquid take advantage inexpensive components. costly complex, especially solvents. simpler principle, since same unit. takes place temperature. hand, scrubbing, stability issue achieving purity customized more energy-demanding Choosing these approaches prioritizing research trivial; projected once $100 captured26Fasihi though value might too optimistic, $200 target pursuing. unclear what needed taken get improvements With extensive thorough analysis aqueous- technologies. do coupling rate-based modeling multi-objective For thermodynamic modeling, Plus solvents, state-of-the-art in-house code fixed bed cycles sorbents.36Casas Schell Pini Fixed CO2/H2 mixtures activated carbon: experiments modeling.Adsorption. 18: 143-161Crossref (100) optimization, connect first-principles models Matlab, algorithms design. As result, able (in MJ kgCO2?1) kgCO2 m?3 h?1) designs, existing plants. indicators (KPIs) input simplified that, despite simplicity, clearly map contributions $ directions follow improvements; e.g., benefits versus operating When comparing literature, although techno-economic analyses published, either rely models,37Azarabadi H. sorbent-focused capture.Appl. 250: 959-975Crossref (46) assumptions literature26Fasihi Scholar,38Deutz Bardow Life-cycle temperature–vacuum adsorption.Nat. 2021; 6: 203-213Crossref (12) analyze single process.19Kiani Scholar,39Sinha Darunte Realff M.J. Kawajiri Systems MIL-101(Cr)-PEI-800 mmen-Mg (dobpdc) adsorbents.Ind. 2017; 56: 750-764Crossref (72) Scholar, 40Sinha parametric techno-economics systems adsorbents.AIChE 65: e16607Crossref 41Stampi-Bombelli der Spek Analysis steam-assisted adsorption.Adsorption. 26: 1183-1197Crossref addition, here consider presence co-adsorption. Accordingly, advances literature (i) detailed model-based comparison (ii) assesses each (iii) identifies weak points providing future R&D, (iv) quantifies how process/material enhance performance. organized follows. schemes methodology, approach analysis. complemented exhaustive supplemental information document. optimization evaluation, methodology. discussion, present results. conclusions summarize conclusions, respectively. alkali-scrubbing Figure 1. thoroughly discussed past literature7Zeman Scholar,8Baciocchi Scholar,12Keith never systematically optimized. Here, shortly features, optimization; reader refer details dedicated absorbed KOH form K2CO3. K2CO3 regenerated forming calcium carbonate, fed calciner CaO work, whole modeled V11, precise computation thermodynamics electrolyte NRTL method, while reliable (available within RadFrac). mechanism alkaline well known two-step process42Astarita Absorption towers.Ind. Fund. 1963; 294-297Crossref (15) Scholar:CO2aq+OH??HCO3?(Equation 1) HCO3?+OH??CO32?+H2O(Equation 2) rate-limiting step represented Equation common reported fastest kinetics.11Holmes