Editing Ammonia (section)

=== Fuel ===
[[File:AmmoniacalGasEngineStreetcarARWaud.jpeg|thumb|Ammoniacal Gas Engine [[Streetcars in New Orleans|Streetcar in New Orleans]] drawn by [[Alfred Waud]] in 1871]]
Ammonia has been used as fuel, and is a proposed alternative to fossil fuels and hydrogen. Being liquid at ambient temperature under its own vapour pressure and having high volumetric and gravimetric energy density, ammonia is considered a suitable carrier for hydrogen,<ref>{{Cite web|date=2022-02-03|title=MOL studies ammonia FSRU concept|url=https://www.offshore-energy.biz/mol-studies-ammonia-fsru-concept/|access-date=2022-02-03|website=Offshore Energy|language=en-US}}</ref> and may be cheaper than direct transport of liquid hydrogen.<ref>{{Cite web|last=Collins (l_collins)|first=Leigh|date=2022-01-27|title=SPECIAL REPORT {{!}} Why shipping pure hydrogen around the world might already be dead in the water {{!}} Recharge|url=https://www.rechargenews.com/energy-transition/special-report-why-shipping-pure-hydrogen-around-the-world-might-already-be-dead-in-the-water/2-1-1155434|access-date=2022-02-03|website=Recharge {{!}} Latest renewable energy news|language=en}}</ref>

Compared to hydrogen, ammonia is easier to store. Compared to [[hydrogen as a fuel]], ammonia is much more energy efficient, and could be produced, stored and delivered at a much lower cost than hydrogen, which must be kept compressed or as a cryogenic liquid.<ref name="Lan-2014" /><ref>{{cite web |last=Lindzon |first=Jared |date=27 February 2019 |title=He's Creating a New Fuel Out of Thin Air – for 85 Cents per Gallon |url=http://www.ozy.com/rising-stars/hes-creating-a-new-fuel-out-of-thin-air-for-85-cents-per-gallon/92686 |access-date=26 April 2019 |website=OZY |archive-date=26 April 2019 |archive-url=https://web.archive.org/web/20190426171820/https://www.ozy.com/rising-stars/hes-creating-a-new-fuel-out-of-thin-air-for-85-cents-per-gallon/92686 |url-status=dead }}</ref> The raw [[energy density]] of liquid ammonia is 11.5&nbsp;MJ/L,<ref name="Lan-2014">{{Cite journal|last1=Lan|first1=Rong|last2=Tao|first2=Shanwen|date=28 August 2014|title=Ammonia as a suitable fuel for fuel cells|journal=Frontiers in Energy Research|volume=2|pages=35|doi=10.3389/fenrg.2014.00035|doi-access=free}}</ref> which is about a third that of [[diesel fuel|diesel]].

Ammonia can be converted back to hydrogen to be used to power hydrogen fuel cells, or it may be used directly within high-temperature [[solid oxide fuel cell|solid oxide]] direct ammonia fuel cells to provide efficient power sources that do not emit [[greenhouse gas]]es.<ref>{{cite journal|last1=Giddey|first1=S.|last2=Badwal|first2=S. P. S.|last3=Munnings|first3=C.|last4=Dolan|first4=M.|title=Ammonia as a Renewable Energy Transportation Media|journal=ACS Sustainable Chemistry & Engineering|volume=5|issue=11|pages=10231–10239|date=10 October 2017|doi=10.1021/acssuschemeng.7b02219}}</ref><ref name="Afif-2016">{{cite journal|last1=Afif|first1=Ahmed|last2=Radenahmad|first2=Nikdilila|last3=Cheok|first3=Quentin|last4=Shams|first4=Shahriar|last5=Hyun Kim|first5=Jung|last6=Azad|first6=Abul|date=2016-02-12|title=Ammonia-fed fuel cells: a comprehensive review|url=https://www.researchgate.net/publication/294579196|journal=[[Renewable and Sustainable Energy Reviews]]|volume=60|pages=822–835|doi=10.1016/j.rser.2016.01.120|bibcode=2016RSERv..60..822A |access-date=2021-01-01}}</ref> Ammonia to hydrogen conversion can be achieved through the [[sodium amide]] process<ref name="David-2014">{{Cite journal |last1=David |first1=William I. F. |last2=Makepeace |first2=Joshua W. |last3=Callear |first3=Samantha K. |last4=Hunter |first4=Hazel M. A. |last5=Taylor |first5=James D. |last6=Wood |first6=Thomas J. |last7=Jones |first7=Martin O. |date=2014-09-24 |title=Hydrogen Production from Ammonia Using Sodium Amide |journal=Journal of the American Chemical Society |volume=136 |issue=38 |pages=13082–13085 |doi=10.1021/ja5042836 |issn=0002-7863 |pmid=24972299 |doi-access=free|bibcode=2014JAChS.13613082D }}</ref> or the catalytic decomposition of ammonia using solid catalysts.<ref>{{Cite journal |last1=Lucentini |first1=Ilaria |last2=García Colli |first2=Germán |last3=Luzi |first3=Carlos D. |last4=Serrano |first4=Isabel |last5=Martínez |first5=Osvaldo M. |last6=Llorca |first6=Jordi |date=2021-06-05 |title=Catalytic ammonia decomposition over Ni–Ru supported on CeO<sub>2</sub> for hydrogen production: Effect of metal loading and kinetic analysis |url=https://www.sciencedirect.com/science/article/pii/S0926337321000229|journal=Applied Catalysis B: Environmental |language=en |volume=286 |pages=119896 |doi=10.1016/j.apcatb.2021.119896 |bibcode=2021AppCB.28619896L |s2cid=233540470 |issn=0926-3373|hdl=2117/364129 |hdl-access=free }}</ref>
[[File:X-15.jpg|thumb|The [[X-15]] [[aircraft]] used ammonia as one component [[fuel]] of its [[rocket engine]]]]
Ammonia engines or ammonia motors, using ammonia as a [[working fluid]], have been proposed and occasionally used.<ref>{{cite web|author=Douglas Self|author-link=Douglas Self|url=http://www.douglas-self.com/MUSEUM/POWER/ammonia/ammonia.htm|title=Ammonia Motors|date=1 October 2007|access-date=28 November 2010}}</ref> The principle is similar to that used in a [[fireless locomotive]], but with ammonia as the working fluid, instead of steam or compressed air. Ammonia engines were used experimentally in the 19th century by [[Goldsworthy Gurney]] in the UK and the [[St. Charles Streetcar Line]] in [[New Orleans]] in the 1870s and 1880s,<ref name="Elbridge Harper Charlton-1965">{{Cite book |title=The Streetcars of New Orleans |author=Louis C. Hennick |author2=Elbridge Harper Charlton |date = 1965 |publisher =Pelican Publishing |isbn=9781455612598 |pages =14–16 }}</ref> and during [[World War II]] ammonia was used to power buses in [[Belgium]].<ref name="Olson-2007" />

Ammonia is sometimes proposed as a practical alternative to [[fossil fuel]] for [[internal combustion engine]]s.<ref name="Olson-2007">{{cite news|url=http://www.energy.iastate.edu/Renewable/ammonia/ammonia/2007/Olson2_NH3.pdf |title=Ammonia as a Transportation Fuel IV |date=15–16 October 2007 |publisher=Norm Olson – Iowa Energy Center |url-status=dead |archive-url=https://web.archive.org/web/20120207092554/http://www.energy.iastate.edu/Renewable/ammonia/ammonia/2007/Olson2_NH3.pdf |archive-date=7 February 2012}}</ref><ref name="Lee-2017">{{cite web |title=Development of new combustion strategy for internal combustion engine fueled by pure ammonia |last1=Lee |first1=Dongeun |last2=Min |first2=Hyungeun |last3=Park |first3=Hyunho |last4=Song |first4=Han Ho |url=https://nh3fuelassociation.org/wp-content/uploads/2017/11/NH3-Energy-2017-Donggeun-Lee.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://nh3fuelassociation.org/wp-content/uploads/2017/11/NH3-Energy-2017-Donggeun-Lee.pdf |archive-date=2022-10-09 |url-status=live |publisher=Seoul National University, Department of Mechanical Engineering |date=2017-11-01 |access-date=2019-01-29}}</ref><ref name="Brohi-2014">{{cite web |title=Ammonia as fuel for internal combustion engines? |author=Brohi, Emtiaz Ali |url=http://publications.lib.chalmers.se/records/fulltext/207145/207145.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://publications.lib.chalmers.se/records/fulltext/207145/207145.pdf |archive-date=2022-10-09 |url-status=live |publisher=Chalmers University of Technology |year=2014 |access-date=2019-01-29}}</ref><ref>{{Cite web |last=Elucidare |date=2 February 2008 |title=Ammonia: New possibilities for hydrogen storage and transportation |url=http://www.elucidare.co.uk/news/Ammonia%20as%20H2%20carrier.pdf |url-status=live |website=Elucidare Limited|archive-url=https://web.archive.org/web/20101008200842/http://www.elucidare.co.uk:80/news/Ammonia%20as%20H2%20carrier.pdf |archive-date=8 October 2010 }}</ref> However, ammonia cannot be easily used in existing [[Otto cycle]] engines because of its very narrow [[#Combustion|flammability range]]. Despite this, several tests have been run.<ref>{{YouTube|L0hBAz6MxC4|Ammonia Powered Car}}</ref><ref>{{cite web |title=Watch 'Ammonia Fuel' |url=http://www.gregvezina.ca |access-date=7 July 2009 |publisher=Greg Vezina}}</ref><ref>{{cite web |title=Welcome to NH3 Car |url=http://www.nh3car.com/ |archive-url=https://web.archive.org/web/20071214103433/http://nh3car.com/ |url-status=usurped |archive-date=14 December 2007 |work=NH3Car.com}}</ref> Its high [[octane rating]] of 120<ref name="bris.ac.uk">{{cite web|url=http://www.chm.bris.ac.uk/motm/ammonia/Ammonia%20MOTM.htm|title=Ammonia|publisher=chm.bris.ac.uk|access-date=3 March 2016}}</ref> and low flame temperature<ref name="Zacharakis-Jutz-2013">{{cite web |title=Characteristics of an SI Engine Using Direct Ammonia Injection |last1=Zacharakis-Jutz |first1=George |last2=Kong |first2=Song-Charng |url=https://nh3fuelassociation.org/wp-content/uploads/2013/10/nh3fcx-song-charng-kong.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://nh3fuelassociation.org/wp-content/uploads/2013/10/nh3fcx-song-charng-kong.pdf |archive-date=2022-10-09 |url-status=live |publisher=Department of Mechanical Engineering, Iowa State University |year=2013 |access-date=2019-01-29}}</ref> allows the use of high compression ratios without a penalty of high [[NOx|{{NOx}}]] production. Since ammonia contains no carbon, its combustion cannot produce [[carbon dioxide]], [[carbon monoxide]], [[hydrocarbons]], or [[soot]].

Ammonia production currently creates 1.8% of global {{CO2}} emissions. 'Green ammonia' is ammonia produced by using [[green hydrogen]] (hydrogen produced by electrolysis with electricity from [[Renewable energy|renewable]] energy), whereas 'blue ammonia' is ammonia produced using [[blue hydrogen]] (hydrogen produced by steam methane reforming) where the carbon dioxide has been captured and stored.<ref>{{Cite web|url=https://royalsociety.org/topics-policy/projects/low-carbon-energy-programme/green-ammonia/|title=Green ammonia &#124; Royal Society|website=royalsociety.org}}</ref>

Rocket engines have also been fueled by ammonia. The [[Reaction Motors XLR99]] rocket engine that powered the {{nowrap|[[X-15]]}} hypersonic research aircraft used liquid ammonia. Although not as powerful as other fuels, it left no [[soot]] in the reusable rocket engine, and its density approximately matches the density of the oxidiser, [[liquid oxygen]], which simplified the aircraft's design.

In 2020, [[Saudi Arabia]] shipped 40 [[metric tons]] of liquid 'blue ammonia' to Japan for use as a fuel.<ref>{{Cite news|date=2020-09-27|title=Saudi Arabia Sends Blue Ammonia to Japan in World-First Shipment|url=https://www.bloomberg.com/news/articles/2020-09-27/saudi-arabia-sends-blue-ammonia-to-japan-in-world-first-shipment|access-date=2020-09-28|website=Bloomberg.com}}</ref> It was produced as a by-product by petrochemical industries, and can be burned without giving off [[greenhouse gas]]es. Its energy density by volume is nearly double that of liquid hydrogen. If the process of creating it can be scaled up via purely renewable resources, producing green ammonia, it could make a major difference in [[avoiding climate change]].<ref>{{Cite web|last1=Service|first1=Robert F.|date=2018-07-12|title=Ammonia—a renewable fuel made from sun, air, and water—could power the globe without carbon|url=https://www.science.org/content/article/ammonia-renewable-fuel-made-sun-air-and-water-could-power-globe-without-carbon|access-date=2020-09-28|website=Science {{!}} AAAS|language=en}}</ref> The company [[ACWA Power]] and the city of [[Neom]] have announced the construction of a green hydrogen and ammonia plant in 2020.<ref>{{Cite web|date=2020-09-17|title=Will Saudi Arabia build the world's largest green hydrogen and ammonia plant?|website=energypost.eu|access-date=2020-10-09|url=https://energypost.eu/will-saudi-arabia-build-the-worlds-largest-green-hydrogen-and-ammonia-plant/}}</ref>

Green ammonia is considered as a potential fuel for future container ships. In 2020, the companies [[DSME]] and [[MAN Energy Solutions]] announced the construction of an ammonia-based ship, DSME plans to commercialize it by 2025.<ref>{{Cite web|date=6 October 2020 |title=DSME gets LR AIP for ammonia-fueled 23,000 TEU boxship|website=Offshore Energy|access-date=9 October 2020|url=https://www.offshore-energy.biz/dsme-gets-lr-aip-for-ammonia-fueled-23000-teu-boxship/}}</ref> The use of ammonia as a potential alternative fuel for [[aircraft]] [[jet engine]]s is also being explored.<ref>{{cite web |url=https://aviafuture.com/index.php/2022/03/30/what-will-power-aircraft-in-the-future/#ammonia |title=What will power aircraft in the future? |date=30 March 2022 |website=Aviafuture |access-date=24 May 2022 }}</ref>

Japan intends to implement a plan to develop ammonia co-firing technology that can increase the use of ammonia in power generation, as part of efforts to assist domestic and other Asian utilities to accelerate their transition to [[carbon neutrality]].<ref>{{cite web |url=https://www.argusmedia.com/en/news/2227810-japan-to-advance-ammonia-cofiring-technology |title=Japan to advance ammonia co-firing technology |date=24 June 2021 |website=[[Argus Media]] |access-date=8 November 2021 }}</ref>
In October 2021, the first International Conference on Fuel Ammonia (ICFA2021) was held.<ref>{{cite web |url=https://icfa2021.com/en/index.html |title=First International Conference on Fuel Ammonia 2021 |date=6 October 2021 |website=ICFA |access-date=7 November 2021 |archive-date=7 November 2021 |archive-url=https://web.archive.org/web/20211107071827/https://icfa2021.com/en/index.html |url-status=dead }}</ref><ref>{{cite web |url=https://www.meti.go.jp/english/press/2021/1012_002.html |date=12 October 2021 |title=First International Conference on Fuel Ammonia Held |website=[[Ministry of Economy, Trade and Industry|METI, Japan]] |access-date=7 November 2021 }}</ref>

In June 2022, [[IHI Corporation]] succeeded in reducing greenhouse gases by over 99% during combustion of liquid ammonia in a 2,000-kilowatt-class gas turbine achieving truly {{CO2}}-free power generation.<ref>{{Cite press release |title={{CO2}}-free power generation achieved with the world's first gas turbine using 100% liquid ammonia |date=16 June 2022 |url=https://www.ihi.co.jp/en/all_news/2022/resources_energy_environment/1197938_3488.html |publisher=[[IHI Corporation]] |access-date=1 July 2022 }}</ref>
In July 2022, [[Quadrilateral Security Dialogue|Quad]] nations of Japan, the U.S., Australia and India agreed to promote technological development for clean-burning hydrogen and ammonia as fuels at the security grouping's first energy meeting.<ref>{{Cite news|date=14 July 2022 
|author=Masaya Kato |title=Quad members agree to promote hydrogen, ammonia fuel tech |url=https://www.ihi.co.jp/en/all_news/2022/resources_energy_environment/1197938_3488.html |publisher=[[The Nikkei]] |access-date=14 July 2022 }}</ref> {{As of|2022}}, however, significant amounts of {{NOx}} are produced.<ref>{{Cite web |title=On the use of ammonia as a fuel – A perspective |url=https://hal-cnrs.archives-ouvertes.fr/hal-03675905/file/2022%20NH3%20perspective.pdf}}</ref> [[Nitrous oxide]] may also be a problem as it is a "''greenhouse gas that is known to possess up to 300 times the Global Warming Potential (GWP) of carbon dioxide''".<ref>{{Cite web |title=Nitrogen Oxides as a By-product of Ammonia/Hydrogen Combustion Regimes |url=https://orca.cardiff.ac.uk/id/eprint/144277/3/ICLCA21_0206%20ed%20V3%20without%20comments.pdf}}</ref>

The [[International Energy Agency|IEA]] forecasts that ammonia will meet approximately 45% of shipping fuel demands by 2050.<ref>{{Cite news |last=Mehta |first=Amgeli |date=May 15, 2023 |title=In the voyage to net-zero, which green shipping fuel will rule the seas? |url=https://www.reuters.com/sustainability/climate-energy/voyage-net-zero-which-green-shipping-fuel-will-rule-seas-2023-05-15/ |work=Reuters}}</ref>

At high temperature and in the presence of a suitable [[catalyst]] ammonia decomposes into its constituent elements.<ref name="White-1905">{{Cite journal |last1=White |first1=Alfred H. |last2=Melville |first2=Wm. |title=The Decomposition of Ammonia at High Temperatures |date=April 1905 |url=https://pubs.acs.org/doi/abs/10.1021/ja01982a005 |journal=Journal of the American Chemical Society |language=en |volume=27 |issue=4 |pages=373–386 |doi=10.1021/ja01982a005 |bibcode=1905JAChS..27..373W |issn=0002-7863}}</ref> Decomposition of ammonia is a slightly endothermic process requiring 23&nbsp;kJ/mol (5.5&nbsp;[[kcal/mol]]) of ammonia, and yields [[hydrogen]] and [[nitrogen]] gas.