Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production
We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 105-fold increase in OH− concentration (p...
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ftpubmed:oai:pubmedcentral.nih.gov:3690887 2023-05-15T17:51:42+02:00 Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production Rau, Greg H. Carroll, Susan A. Bourcier, William L. Singleton, Michael J. Smith, Megan M. Aines, Roger D. 2013-06-18 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3690887 http://www.ncbi.nlm.nih.gov/pubmed/23729814 https://doi.org/10.1073/pnas.1222358110 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3690887 http://www.ncbi.nlm.nih.gov/pubmed/23729814 http://dx.doi.org/10.1073/pnas.1222358110 Freely available online through the PNAS open access option. Physical Sciences Text 2013 ftpubmed https://doi.org/10.1073/pnas.1222358110 2013-09-05T01:30:59Z We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 105-fold increase in OH− concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na2SO4 solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After electrolysis, full equilibration of the alkalized solution with air led to a significant pH reduction and as much as a 45-fold increase in dissolved inorganic carbon concentration. This demonstrated significant spontaneous air CO2 capture, chemical conversion, and storage as a bicarbonate, predominantly as NaHCO3. The excess OH− initially formed in these experiments apparently resulted via neutralization of the anolyte acid, H2SO4, by reaction with the base mineral silicate at the anode, producing mineral sulfate and silica. This allowed the NaOH, normally generated at the cathode, to go unneutralized and to accumulate in the bulk electrolyte, ultimately reacting with atmospheric CO2 to form dissolved bicarbonate. Using nongrid or nonpeak renewable electricity, optimized systems at large scale might allow relatively high-capacity, energy-efficient (<300 kJ/mol of CO2 captured), and inexpensive (<$100 per tonne of CO2 mitigated) removal of excess air CO2 with production of carbon-negative H2. Furthermore, when added to the ocean, the produced hydroxide and/or (bi)carbonate could be useful in reducing sea-to-air CO2 emissions and in neutralizing or offsetting the effects of ongoing ocean acidification. Text Ocean acidification PubMed Central (PMC) Proceedings of the National Academy of Sciences 110 25 10095 10100 |
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Physical Sciences Rau, Greg H. Carroll, Susan A. Bourcier, William L. Singleton, Michael J. Smith, Megan M. Aines, Roger D. Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production |
topic_facet |
Physical Sciences |
description |
We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 105-fold increase in OH− concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na2SO4 solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After electrolysis, full equilibration of the alkalized solution with air led to a significant pH reduction and as much as a 45-fold increase in dissolved inorganic carbon concentration. This demonstrated significant spontaneous air CO2 capture, chemical conversion, and storage as a bicarbonate, predominantly as NaHCO3. The excess OH− initially formed in these experiments apparently resulted via neutralization of the anolyte acid, H2SO4, by reaction with the base mineral silicate at the anode, producing mineral sulfate and silica. This allowed the NaOH, normally generated at the cathode, to go unneutralized and to accumulate in the bulk electrolyte, ultimately reacting with atmospheric CO2 to form dissolved bicarbonate. Using nongrid or nonpeak renewable electricity, optimized systems at large scale might allow relatively high-capacity, energy-efficient (<300 kJ/mol of CO2 captured), and inexpensive (<$100 per tonne of CO2 mitigated) removal of excess air CO2 with production of carbon-negative H2. Furthermore, when added to the ocean, the produced hydroxide and/or (bi)carbonate could be useful in reducing sea-to-air CO2 emissions and in neutralizing or offsetting the effects of ongoing ocean acidification. |
format |
Text |
author |
Rau, Greg H. Carroll, Susan A. Bourcier, William L. Singleton, Michael J. Smith, Megan M. Aines, Roger D. |
author_facet |
Rau, Greg H. Carroll, Susan A. Bourcier, William L. Singleton, Michael J. Smith, Megan M. Aines, Roger D. |
author_sort |
Rau, Greg H. |
title |
Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production |
title_short |
Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production |
title_full |
Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production |
title_fullStr |
Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production |
title_full_unstemmed |
Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production |
title_sort |
direct electrolytic dissolution of silicate minerals for air co2 mitigation and carbon-negative h2 production |
publisher |
National Academy of Sciences |
publishDate |
2013 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3690887 http://www.ncbi.nlm.nih.gov/pubmed/23729814 https://doi.org/10.1073/pnas.1222358110 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3690887 http://www.ncbi.nlm.nih.gov/pubmed/23729814 http://dx.doi.org/10.1073/pnas.1222358110 |
op_rights |
Freely available online through the PNAS open access option. |
op_doi |
https://doi.org/10.1073/pnas.1222358110 |
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Proceedings of the National Academy of Sciences |
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110 |
container_issue |
25 |
container_start_page |
10095 |
op_container_end_page |
10100 |
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1766158924499648512 |