E-diesel is a synthetic diesel fuel for use in automobiles. Currently, e-diesel is created at two sites: by an Audi research facility Germany in partnership with a company named Sunfire, and in Texas. The fuel is created from carbon dioxide, water, and electricity with a process powered by renewable energy sources to create a liquid energy carrier called blue crude (in contrast to regular crude oil) which is then refined to generate e-diesel. E-diesel is considered to be a carbon-neutral fuel as it does not extract new carbon and the energy sources to drive the process are from carbon-neutral sources.
Catalytic conversions[edit]
Water | CO2 | ||||||||||||||||||||
Electrolysis of Water | |||||||||||||||||||||
Oxygen | Hydrogen | ||||||||||||||||||||
Conversion Reactor | |||||||||||||||||||||
Water | Hydrogen | CO | |||||||||||||||||||
F-T Reactor | |||||||||||||||||||||
Sunfire, a clean technology company, operates a pilot plant in Dresden, Germany. The current process involves high-temperature electrolysis powered by electricity generated from renewable energy sources to split water into hydrogen and oxygen. The next two chemical processes to create a liquid energy carrier called blue crude are done at a temperature of 220 °C (428 °F) and a pressure of 25 bars (2,500 kPa). In a conversion step, hydrogen and carbon dioxide are used to create syngas with water as byproduct. The syngas, which contains carbon monoxide and hydrogen, reacts to generate the blue crude.
- Sunfire power-to-liquids system: Base products are carbon dioxide (CO2) and water (H2O)[1]
- 1st step: Electrolysis of Water (SOEC) −water is split into hydrogen and oxygen.
- 2nd step: Conversion Reactor (RWGSR) −hydrogen and carbon dioxide are inputs to the Conversion Reactor that outputs hydrogen, carbon monoxide, and water.
- 3rd step: F-T Reactor −hydrogen and carbon monoxide are inputs[2][3] to the F-T Reactor that outputs paraffinic and olefinic hydrocarbons, ranging from methane to high molecular weight waxes.[4]
The third step is also known as Fischer–Tropsch process which was first developed in 1925 by German chemists Franz Fischer and Hans Tropsch. After the blue crude is produced, it can be refined to create e-diesel on site, saving the fuel and other infrastructure costs on crude transportation.[5] As of April 2015, Sunfire has a capability to produce a limited amount of fuel at 160 litres (35 imp gal; 42 US gal) a day. There is a plan to increase the production to an industrial scale.[6]
Audi also partners with a company named Climeworks which manufactures Direct Air Capture technology. Climeworks technologies can absorb atmospheric carbon dioxide which is chemically captured at the surface of a sorbent until it becomes saturated. At that point, the sorbent is introduced with 95 °C (203 °F) heat in a desorption cycle to drive out the high-purity carbon dioxide that can be used during the conversion step of the blue crude generation process. The atmospheric carbon dioxide capturing process has 90% of energy demand in the form of low-temperature heat and the rest from electrical energy for pumping and control. The combined plant of Climeworks and Sunfire in Dresden became operational in November 2014.[5] As of April 2015, an Audi A8 driven by Federal Minister of Education and Research in Germany is using the e-diesel fuel.[7][8]
A plant on Herøya in Norway, producing 10 million liters per year, is being considered, as CO2 from a fertilizer plant is readily available and electricity is relatively cheap in Norway.[9]
An E-diesel plant in Texas started in 2024.[10]
Properties[edit]
As much as eighty percent of blue crude can be converted into e-diesel. The fuel contains no sulfur or aromatics, and has a high cetane number. These properties allow it to be blended with typical fossil diesel and used as a replacement fuel in automobiles with diesel engines.[5]
Oxygen by-product[edit]
In future designs,[11][12] the oxygen by-product may be combined with renewable natural gas in the oxidative coupling of methane to ethylene:[13][14]
- 2CH
4 + O
2 → C
2H
4 + 2H
2O
The reaction is exothermic (∆H = -280 kJ/mol) and occurs at high temperatures (750–950 ˚C).[15] The yield of the desired C
2 products is reduced by non-selective reactions of methyl radicals with the reactor surface and oxygen, which produces carbon monoxide and carbon dioxide by-products. Another ethylene production initiative developed by the European Commission through the Seventh Framework Programme for Research and Technological Development is the OCMOL process, which is the Oxidative Coupling of Methane (OCM) and simultaneous Reforming of Methane (RM) in a fully integrated reactor.[16]
Biocatalytic conversions[edit]
![](https://upload.wikimedia.org/wikipedia/en/thumb/3/3e/Helioculture_image.png/300px-Helioculture_image.png)
Audi also partnered with a now-defunct United States company, Joule, to develop Sunflow-D as e-diesel for Audi. Joule's planned plant in New Mexico involved the use of genetically modified microorganisms in bright sunlight to act as catalyst for the conversion of carbon dioxide and salty water into hydrocarbons.[5][17] The process could be modified for longer molecular chains to produce alkanes in order to create synthetic diesel.[18][19][20][21]
Joule was the first company to patent a modified organism that continuously secretes hydrocarbon fuel. The organism is a single-celled cyanobacterium, also known as blue-green algae, although it is technically not an algae. It produces the fuel using photosynthesis, the same process that multi-cellular green plants use, to make sugars and other materials from water, carbon dioxide, and sunlight.[22]
Similar initiatives[edit]
There are other initiatives to create synthetic fuel from carbon dioxide and water, some are called e-diesel. The water splitting methods vary.
- Concentrated solar power
- High-temperature electrolysis
- 2004 Syntrolysis Fuels – Idaho National Laboratory and Ceramatec, Inc. (US).[38][39][40][41][42][43]
- 2008 WindFuels – Doty Energy (US).[44][45]
- 2012 Air Fuel Synthesis – Air Fuel Synthesis Ltd (UK).[46][47][48][49][50]
- 2013 Green Feed – Ben-Gurion University of the Negev and Israel Strategic Alternative Energy Foundation (I-SAEF).[51][52][53][54]
- 2014 Audi E-diesel[55][56][57]
The U.S. Naval Research Laboratory (NRL) is designing a power-to-liquids system using the Fischer-Tropsch Process to create fuel on board a ship at sea,[58] with the base products carbon dioxide (CO2) and water (H2O) being derived from sea water via "An Electrochemical Module Configuration For The Continuous Acidification Of Alkaline Water Sources And Recovery Of CO2 With Continuous Hydrogen Gas Production".[59][60]
See also[edit]
References[edit]
- ^ "Fuels from solar energy, CO2 and water". sunfire.de. Sunfire GmbH. Archived from the original on 6 May 2015. Retrieved 8 May 2015.
- ^ Ciferno, Jared; Marano, John (June 2002). "Benchmarking Biomass Gasification Technologies for Fuels, Chemicals and Hydrogen Production" (PDF). National Energy Technology Laboratory. Archived from the original (PDF) on 19 May 2015. Retrieved 19 May 2015.
- ^ "Syngas Optimized for Intended Products". NETL - Gasification Introduction. U.S. DEPARTMENT OF ENERGY. Archived from the original on 19 May 2015. Retrieved 19 May 2015.
- ^ Sang-Eon Park; Jong-San Chang; Kyu-Wan Lee (27 October 2004). Carbon Dioxide Utilization for Global Sustainability: Proceedings of the 7th International Conference on Carbon Dioxide Utilization, Seoul, Korea, October 12-16, 2003. Elsevier. p. 18. ISBN 978-0-08-047217-1.
Traditional Fischer-Tropsch synthesis using CO/H
2 feedgas produces paraffinic and olefinic hydrocarbons, ranging from methane to high molecular weight waxes. - ^ a b c d "Audi in new e-fuels project: synthetic diesel from water, air-captured CO2 and green electricity; "Blue Crude"". Green Car Congress. 14 November 2014. Retrieved 29 April 2015.
- ^ MacDonald, Fiona (27 April 2015). "Audi has successfully made diesel fuel from carbon dioxide and water". Science Alert. Retrieved 29 April 2015.
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- ^ "Norsk selskap kan bli først i verden til å produsere Audis "vidunderdiesel"". Teknisk Ukeblad. 2016-06-10. Retrieved 11 June 2016.
- ^ Collins, Leigh (22 March 2024). "World's first commercial e-fuel plant opens, producing diesel from green hydrogen — backed by Bill Gates and Jeff Bezos". rechargenews.com.
- ^ "HELMETH EU: A Project in the Amount of EUR 3.8 Million for More Efficient Methane Gas Production from Regenerative Power by Thermal Interlinkage of Chemical Processes". Karlsruhe Institute of Technology. Karlsruhe Institute of Technology. 10 April 2014. Retrieved 21 May 2015.
- ^ Kondratenko, Evgenii V.; Rodemerck, Uwe (9 January 2013). "A Dual-Reactor Concept for the High-Yielding Conversion of Methane into Higher Hydrocarbons". ChemCatChem. 5 (3): 697–700. doi:10.1002/cctc.201200779. S2CID 97578206.
- ^ Zhang, Q. (2003). "Recent Progress in Direct Partial Oxidation of Methane to Methanol". J. Natural Gas Chem. 12: 81–89.
- ^ Olah, G., Molnar, A. "Hydrocarbon Chemistry" John Wiley & Sons, New York, 2003. ISBN 978-0-471-41782-8.
- ^ Lunsford, J.H. (1995). "The catalytic coupling of methane". Angew. Chem. Int. Ed. Engl. 34 (9): 970–980. doi:10.1002/anie.199509701.
- ^ "OCMOL: Oxidative Coupling of Methane followed by Oligomerization to Liquids" (PDF). Archived from the original (PDF) on 2015-05-21. Retrieved 2015-05-21.
- ^ "A Transformative Production Platform for Liquid Fuel from the Sun" (PDF). sae.org. Joule. Retrieved 29 April 2015.
- ^ Kacher, Georg (29 July 2013). "CAR tech: Audi's miracle e-fuel (2013)". Car Magazine. Retrieved 29 April 2015.
- ^ "Joule and Audi partner on sustainable liquid transportation fuels". Green Car Congress. 17 September 2012. Retrieved 7 May 2015.
- ^ "Audi e-diesel and e-ethanol". Audi. Retrieved 7 May 2015.
- ^ Casey, Tina (May 12, 2015). "Buh-Bye, Corn Ethanol: Joule Makes The Same Thing From Recycled CO2". CleanTechnica. Sustainable Enterprises Media, Inc. Retrieved 20 May 2015.
- ^ WALD, MATTHEW L. (September 13, 2010). "Biotech Company to Patent Fuel-Secreting Bacterium". No. September 14, 2010, on page B2 of the New York edition. The New York Times Company. NYTimes.com. Retrieved 6 May 2015.
- ^ "Sunshine to Petrol". Sandia National Laboratories. United States Department of Energy (DOE). Archived from the original on 18 May 2015. Retrieved 15 May 2015.
- ^ SNL: Sunshine to Petrol - Solar Recycling of Carbon Dioxide into Hydrocarbon Fuels
- ^ "Sandia and Sunshine-to-Petrol: Renewable Drop-in Transportation Fuels". Federal Business Opportunities. U.S. Federal Government. Oct 29, 2013. Retrieved 15 May 2015.
- ^ Biello, David (September 23, 2010). "Reverse Combustion: Can CO2 Be Turned Back into Fuel?". Scientific American - Energy & Sustainability. Retrieved 17 May 2015.
- ^ Lavelle, Marianne (August 11, 2011). "Carbon Recycling: Mining the Air for Fuel". National Geographic - News. National Geographic Society. Archived from the original on September 24, 2011. Retrieved 19 May 2015.
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- ^ Newsletter NewCO2Fuels, Issue 1, September 2012
- ^ From challenge to opportunity New CO
2 Fuels: An Introduction... - ^ "SOLAR-JET Project". SOLAR-JET. SOLAR-JET Project Office: ARTTIC. Retrieved 15 May 2015.
- ^ "Sunlight to jet fuel". The ETH Zurich. Eidgenössische Technische Hochschule Zürich. Retrieved 15 May 2015.
- ^ Alexander, Meg (May 1, 2014). ""Solar" jet fuel created from water and carbon dioxide". Gizmag. Gizmag. Retrieved 15 May 2015.
- ^ "SOLARJET demonstrates full process for thermochemical production of renewable jet fuel from H2O & CO2". Green Car Congress. BioAge Group, LLC. 28 April 2015. Retrieved 15 May 2015.
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2. ASME 2007 International Mechanical Engineering Congress and Exposition. Vol. 15: Sustainable Products and Processes. ASME. pp. 185–194. doi:10.1115/IMECE2007-43667. ISBN 978-0-7918-4309-3. - ^ Nuclear Hydrogen Initiative Overview
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- ^ "BGU Researchers Develop New Type of Crude Oil Using Carbon Dioxide and Hydrogen". American Associates (Ben-Gurion University of the Negev). American Associates (AABGU). Archived from the original on 18 May 2015. Retrieved 15 May 2015.
- ^ "BGU researchers developing more efficient process for hydrogenation of CO2 to synthetic crude". Green Car Congress. BioAge Group, LLC. 21 November 2013. Retrieved 15 May 2015.
- ^ "Fuel of the future: Research facility in Dresden produces first batch of Audi e-diesel". Audi MediaServices - Press release. Ingolstadt/Berlin: AUDI AG. 2015-04-21. Retrieved 23 May 2015.
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- ^ The total carbon content of the world's oceans is roughly 38,000 GtC. Over 95% of this carbon is in the form of dissolved bicarbonate ion (HCO3 −). (Cline 1992, The Economics of Global Warming; Institute for International Economics: Washington D.C.). The dissolved bicarbonate and carbonate of the ocean is essentially bound CO2 and the sum of these species along with gaseous CO2, shown in the following equation, represents the total carbon dioxide concentration [CO2]T, of the world's oceans. Σ[CO2]T=[CO2(g)]l+[HCO3 −]+[CO3 2−]
- ^ E-benzin
External links[edit]
- Sustainable Transportation Fuels from Off-Peak Wind Energy, CO
2, and Water - Options to dissociate CO
2 for sustainable sunlight-to-fuel pathways - Perspectives in electrolysis and CO
2 recycling Archived 2016-03-04 at the Wayback Machine - Chemical Processes for a Sustainable Future - ch 8. Renewable Energy, CO
2 and an Anthropogenic Carbon Cycle