{"id":928,"date":"2015-08-20T03:46:55","date_gmt":"2015-08-20T03:46:55","guid":{"rendered":"http:\/\/www.kurzweilai.net\/?p=258657"},"modified":"2015-08-31T21:25:04","modified_gmt":"2015-08-31T21:25:04","slug":"diamonds-from-the-sky-approach-to-turn-co2-into-valuable-carbon-nanofibers","status":"publish","type":"post","link":"https:\/\/hoo.central12.com\/fugic\/2015\/08\/20\/diamonds-from-the-sky-approach-to-turn-co2-into-valuable-carbon-nanofibers\/","title":{"rendered":"‘Diamonds from the sky’ approach to turn CO2 into valuable carbon nanofibers"},"content":{"rendered":"
\"\"

Researchers are removing a greenhouse gas from the air while generating carbon nanofibers like these (credit: Stuart Licht, Ph.D)<\/p><\/div>\n

A research team of chemists at George Washington University<\/a> has developed a technology that can economically convert atmospheric CO2\u00a0directly from the air into highly valued carbon nanofibers for industrial and consumer products — converting an anthropogenic greenhouse gas from a climate change problem to a valuable commodity, they say.<\/p>\n

The team presented their research today (Aug. 19) at the 250th\u00a0National Meeting & Exposition of the American Chemical Society (ACS)<\/a>.<\/p>\n

\u201cSuch nanofibers are used to make strong carbon composites, such as those used in the Boeing Dreamliner<\/a>, as well as in high-end sports equipment, wind turbine blades and a host of other products,\u201d said Stuart Licht, Ph.D.<\/a>, team leader.<\/p>\n

Previously, the researchers had made fertilizer and cement without emitting CO2, which they reported. Now, the team, which includes postdoctoral fellow Jiawen Ren, Ph.D.<\/a>, and graduate student Jessica Stuart<\/a>, says their research could shift CO2\u00a0from a global-warming problem to a feed stock for the manufacture of in-demand carbon nanofibers.<\/p>\n

Licht calls his approach \u201cdiamonds from the sky.\u201d That refers to carbon being the material that diamonds are made of, and also hints at the high value of the products, such as carbon nanofibers.<\/p>\n

A low-energy, high-efficiency process<\/strong><\/p>\n

The researchers claim this low-energy process can be run efficiently, using only a few volts of electricity, sunlight, and a whole lot of carbon dioxide. The system uses electrolytic syntheses to make the nanofibers. Here’s how:<\/p>\n

    \n
  1. To power the syntheses, heat and electricity are produced through a hybrid and extremely efficient concentrating solar-energy system. The system focuses the sun\u2019s rays on a photovoltaic solar cell to generate electricity and on a second system to generate heat and thermal energy, which raises the temperature of an electrolytic cell.<\/li>\n
  2. CO2\u00a0is broken down in a high-temperature electrolytic bath of molten carbonates at 1,380 degrees F (750 degrees C).<\/li>\n
  3. Atmospheric air is added to an electrolytic cell.<\/li>\n
  4. The CO2\u00a0dissolves when subjected to the heat and direct current through electrodes of nickel and steel.<\/li>\n
  5. The carbon nanofibers build up on the steel electrode, where they can be removed.<\/li>\n<\/ol>\n

    Licht estimates electrical energy costs of this \u201csolar thermal electrochemical process\u201d to be around $1,000 per ton of carbon nanofiber product. That means the cost of running the system is hundreds of times less than the value of product output, he says.<\/p>\n

    Decreasing CO2 to pre-industrial-revolution levels<\/strong><\/p>\n

    \u201cWe calculate that with a physical area less than 10 percent the size of the Sahara Desert, our process could remove enough CO2\u00a0to decrease atmospheric levels to those of the pre-industrial revolution within 10 years,\u201d he says.<\/p>\n

    At this time, the system is experimental. Licht\u2019s biggest challenge will be to ramp up the process and gain experience to make consistently sized nanofibers. \u201cWe are scaling up quickly,\u201d he adds, \u201cand soon should be in range of making tens of grams of nanofibers an hour.\u201d<\/p>\n

    Licht explains that one advance the group has recently achieved is the ability to synthesize carbon fibers using even less energy than when the process was initially developed. \u201cCarbon nanofiber growth can occur at less than 1 volt at 750 degrees C, which for example is much less than the 3–5 volts used in the 1,000 degree C industrial formation of aluminum,\u201d he says.<\/p>\n

    No published details on overall energy costs and efficiency are yet available (to be updated).<\/p>\n

    \n

    Abstract of New approach to carbon dioxide utilization: The carbon molten air battery<\/em><\/strong><\/p>\n

    <\/em><\/strong>As the levels of carbon dioxide (CO2<\/sub>) increase in the Earth\u2019s atmosphere, the effects on climate change become increasingly apparent. As the demand to reduce our dependence on fossils fuels and lower our carbon emissions increases, a transition to renewable energy sources is necessary. Cost effective large-scale electrical energy storage must be established for renewable energy to become a sustainable option for the future. We’ve previously shown that carbon dioxide can be captured directly from the air at solar efficiencies as high as 50%, and that carbon dioxide associated with cement formation and the production of other commodities can be electrochemically avoided in the STEP process.1-3<\/sup><\/p>\n

    The carbon molten air battery, presented by our group in late 2013, is attractive due to its scalability, location flexibility, and construction from readily available resources, providing a battery that can be useful for large scale applications, such as the storage of renewable electricity.4<\/sup><\/p>\n

    Uncommonly, the carbon molten air battery can utilize carbon dioxide directly from the air:
    \n(1) charging: CO2(g)\u00a0<\/sub>-> C(solid)<\/sub>\u00a0+ O2(g)<\/sub>
    \n(2) discharging: C(solid)<\/sub>\u00a0+ O2(g)<\/sub>\u00a0-> CO2(g)<\/sub>
    \nMore specifically, in a molten carbonate electrolyte containing added oxide, such as lithium carbonate with lithium oxide, the 4 electron charging reaction eq. 1 approaches 100% faradic efficiency and can be described as the following two equations:
    \n(1a) O2-<\/sup>(dissolved)\u00a0<\/sub>+ CO2(g)<\/sub>\u00a0-> CO3<\/sub>2-<\/sup>(molten)<\/sub>
    \n(1b) CO3<\/sub>2-<\/sup>(molten)\u00a0<\/sub>-> C(solid)<\/sub>\u00a0+ O2(g)<\/sub>\u00a0+ O2-<\/sup>(dissolved)<\/sub>
    \nThus, powered by carbon formed directly from the CO2<\/sub>\u00a0in our earth\u2019s atmosphere, the carbon molten air battery is a viable system to provide large-scale energy storage.<\/p>\n

    1<\/sup>S. Licht,\u00a0”Efficient Solar-Driven Synthesis, Carbon Capture, and Desalinization, STEP: Solar Thermal Electrochemical Production of Fuels, Metals, Bleach,” Advanced Materials<\/em>,\u00a047<\/em>, 5592 (2011).
    \n2<\/sup>S. Licht, H. Wu, C. Hettige, B. Wang, J. Lau, J. Asercion, J. Stuart “STEP Cement:\u00a0Solar\u00a0Thermal\u00a0Electrochemical Production of CaO without CO2<\/sub>\u00a0emission,\u201d\u00a0Chemical Communications<\/em>,\u00a048, 6019 (2012).
    \n3<\/sup>S. Licht, B. Cui, B. Wang, F.-F. Li, J. Lau, S. Liu,” Ammonia synthesis by N2<\/sub>\u00a0and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2<\/sub>O3<\/sub>,”\u00a0Science,\u00a0<\/em>345, 637 (2014).
    \n4<\/sup>S. Licht, B. Cui, J. Stuart, B. Wang, J. Lau, “Molten Air Batteries – A new, highest energy class of rechargeable batteries,” Energy & Environmental Science<\/em>,\u00a06, 3646 (2013).<\/p>\n","protected":false},"excerpt":{"rendered":"

    A research team of chemists at George Washington University has developed a technology that can economically convert atmospheric CO2 directly from the air into highly valued carbon nanofibers for industrial and consumer products — converting an anthropogenic greenhouse gas from a climate change problem to a valuable commodity, they say. The team presented their research today […]<\/p>\n","protected":false},"author":13,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[68,52,55,43],"tags":[],"class_list":["post-928","post","type-post","status-publish","format-standard","hentry","category-energy","category-environmentclimate","category-nanotechmaterials-science","category-news"],"_links":{"self":[{"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/posts\/928"}],"collection":[{"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/comments?post=928"}],"version-history":[{"count":2,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/posts\/928\/revisions"}],"predecessor-version":[{"id":1196,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/posts\/928\/revisions\/1196"}],"wp:attachment":[{"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/media?parent=928"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/categories?post=928"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hoo.central12.com\/fugic\/wp-json\/wp\/v2\/tags?post=928"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}