Compressed-air car: Difference between revisions

A '''compressed-air car''' is a [[compressed-air vehicle]] fueledpowered by [[pressure vessels]] filled with [[compressed air]]. It is propelled by the release and expansion of the air within a [[Pneumatic motor|motor adapted to compressed air]]. The car might be powered solely by air, or combined (as in a hybrid electric vehicle) with other fuels such as [[gasoline]], [[Diesel fuel|diesel]], or an electric plant with [[regenerative braking]].

In 2020, Dr. Reza Alizade Evrin of [[Ontario Tech University]] developed an [[isothermal]] [[compressed air vehicle]].<ref name="Compressed air cars for urban transportation"/><ref name="Experimental investigation of a compressed air vehicle prototype with phase change materials for heat recovery"/> This prototype used [[low pressure]] air tanks and exhaust air recovery to power a paraffin [[heat exchanger]] system. Its [[energy efficiency (physics)|energy efficiency]] reached 74%. This is as much as 90% of the efficiency of [[lithium-ion]] [[electric car]]s. It had a driving range of 140 km140 km (86 mi.). Efficiency and range might be increased by a number of practical improvements. For example, combining the storage tank into the car chassis, higher pressure tanks, new rotary engines, and a more efficient heat exchanger. Also, the weight and cost of tanks and pneumatic parts might be reduced by using [[recycled]] and [[bio-based]] [[thermoplastic]]s.

This technology might develop into an inexpensive, greenclean transportation technology. The energy, vehicles and compressors might be easily produced easily by decentralized methods, even [[circular industry]]. Using the plasticsplastic might permit open source fabrication using [[numerical control]], including [[additive manufacturing]]. The compressed air for such vehicles might be easily produced easily by common formstypes of [[renewable energy]]. For example, multistage [[air compressor]]s and intercoolers or [[hydraulic pump]]s might be attached directly to [[trompe]]s, [[hydropower]], [[VAWT]] [[wind turbines]] or [[stirling engine]]s using a [[solar concentrator]]. Direct mechanical compression avoids the Carnot inefficiencies of heat engines. Insulated storage of compressed air avoids [[energy conversion]] and battery storage. Heat-based systems might utilizeuse tankage of solar-heated [[molten salt]]s driving a [[heat exchanger]] rather than an onboard [[heat recovery]] system. [[Electric energy]], [[electric grid]]s and their issues might be avoided.

[[File:Di Pietro Engine Animation2.gif|thumb|Dipietro eccentric shaft, with a rotary vane air engine{{clarify|how is this supposed to work?|date=August 2023}}]]

There have been several dubious claims with undisclosed information. The "di pietro" engine has been partially tested partially with [[CAD]] and [[finite element analysis]] programs. The results were published by [[Jarosław Zwierzchowski]] from [[Lodz University of Technology]] in 2017,.<ref>{{cite web|url=https://www.researchgate.net/publication/316884692 |title=Design type air engine Di Pietro |date=2017-07-18 |accessdate=2017-10-13}}</ref>. This motor is an eccentric shaft vane motor that uses low air pressure.{{clarify|How is this supposed to work?|date=August 2023}}

{{Main|Compressed -air tankenergy storage}}

[[File:Hyundai nexo high pressure hydrogen tank safety.jpg|thumb|Hyundai nexo high High-pressure hydrogen tank safety.]]

[[File:DuraStor consortium Thermoplastic composite pressure vessels.png|thumb|DuraStor consortium Thermoplastic compositeComposite pressure vesselsvessel for hydrogen vehicles. <ref name="compositesworld.com">{{cite web|url=https://www.compositesworld.com/articles/thermoplastic-composite-pressure-vessels-for-fcvs |title=Thermoplastic composite pressure vessels for FCVs |publisher=compositesworld.com |date=2015-02-01 |accessdate=2015-02-01}}</ref>]]

The air storage tanks usable in compressed air cars can be low pressure (9 atm) or high pressure (240+ atm). Thus, they can be made of [[composite material]]s like [[thermoplastic]]s and fiber reinforced thermoplastics,<ref name="compositesworld.com"/><ref name="plastics.gl">{{cite web|url=https://www.plastics.gl/automotive/high-pressure-gas-tanks-in-thermoplastic-composites/ |title=High pressure gas tanks in thermoplastic composites |publisher=plastics.gl |date=2014-05-01 |accessdate=2014-05-01}}</ref> This might permit low priced tankage. It might be made by [[rotational molding]]. Such tanks can be much lighter than [[LitiumLithium iron phosphate battery|lithium-iron]] batteries and 70% lighter than steel tanks. They resist rust from air, water and condensation. They last longer with less maintenance.

===Compressed air production, storage and energy efficiency and densitystorage===

[[File:Wind Turbine Air Compressor.jpg|thumb|Wind Turbineturbine Airair Compressor posted Fieldlinescompressor.com: The Otherpower discussion board <ref name="fieldlines.com">{{cite web|url=https://www.fieldlines.com/index.php?topic=148883.0 |title=Wind Turbineturbine Air Compressorair compressor. |accessdate=2015-07-13}}</ref>]]

[[File:wind turbine powered hydraulic pump with Open Accumulator for Isothermal Compressed Air Energy Storage ICAES System.png|thumb|windWind turbine powered hydraulic pump with Open Accumulator for Isothermal Compressed Air Energy Storage ICAES System. <ref name="researchgate.net">{{cite web|url=https://www.researchgate.net/publication/320288204 |title=Open Accumulator Isothermal Compressed Air Energy Storage (OA-ICAES) System |accessdate=2018-07-13}}</ref>]]

[[Compressed air]] has a low [[energy density]], however nearby isothermal compressed air storage (ICAES) has almost 4 times [[lithium-ion]] batteries capacity: 2.7 MJ/kg or 3.6 MJ/m³.<ref name="semanticscholar.org"/> Compressed air can also be produced by attaching an [[air compressor]] or [[hydraulic pump]] to a wind turbine <ref name="fieldlines.com"/><ref name="researchgate.net"/> or by using a river, tidal or wave [[hydropower]] turbine. These all convert directly from mechanical to pneumatic energy. Eliminating electricity from the loopcycle gives higher efficiency overall. It is also possible to use thermal solar energy with a parabolic or [[Fresnel lens]] [[solar concentrator]] to power a thermal [[Stirling engine]]. This can move the compressor or pump. Solar Stirling is more efficient than solar steam or photovoltaic.

Compressed air cars are emission free. They also do not require a connection to the electric grid. A [[wind turbine]] or other [[renewable energy]] source can directly drive an [[air compressor]] or [[hydraulic pump]]. Compressed air cars do not rely on [[petrol stations]] or an [[electric grid]]. While centralized infrastructure might not be needed, it is an option. Tankage can be directly shipped, or a pipeline can be utilized.Compressed air is normally filtered to protect the compressor machinery. Therefore, discharge air has very little suspended dust. There may be some lubricants emitted by some systemsystems, but further development might reduce this with oil free compressors and intercoolers

There can be a single conversion of mechanical energy to pneumatic or hydraulic energy.<ref name="researchgate.net"/> Therefore, compressed air can have high [[Energy efficiency (physics)|energy efficiency]] when using mechanical [[renewable energy]] such as wind turbines or hydropower. [[Thermal energy]] to [[mechanical energy]] conversion is possible, but less efficient due to Carnot conversion inefficiencies. Thermal storage of heat from a renewable solar source is also possible using a phase change material such as a [[molten salt]].

Various companies are investing in the [[R&D|research, development and deployment]] of compressed air cars. The MDI Air Car made its public [[South Africa]]n debut in 2002.<ref name="HowStuffWorks">{{cite web| title=How Air-Powered Cars Will Work | author=Kevin Bonsor | publisher=[[HowStuffWorks]] |date=2005-10-25 | access-date=2006-05-25 | url=http://auto.howstuffworks.com/air-car.htm/printable}}</ref> It was predicted to be in production "within six months" in January 2004.<ref name="SundayTimes">{{cite news | title=Gone with the wind | author=Robyn Curnow | newspaper=[[The Sunday Times (UK)]] |date=2004-01-11 | access-date=2006-05-25 | url=http://www.timesonline.co.uk/printFriendly/0,,1-120-957436-120,00.html | location=London}}{{dead link|date=September 2024|bot=medic}}{{cbignore|bot=medic}}</ref> As of January 20092022, it was not in production.

Peugeot and Citroën announced that they intended to build a car using compressed air as an energy source. However, it utilizes a hybrid system. A gasoline engine propels the car overmore than 70&nbsp;km/h or when the compressed air tank has been depleted.<ref>{{cite web|url=http://gas2.org/2013/02/18/compressed-air-hybrid-car-developed/ |title=Compressed-Air Hybrid Car Developed |publisher=Gas2.org |date=2013-02-18 |access-date=2013-09-08}}</ref><ref>{{cite web|url=http://inhabitat.com/peugeot-announces-plans-to-release-a-hybrid-car-that-runs-on-compressed-air-by-2016/|title=Peugeot Announces Plans to Release a Hybrid Car That Runs on Compressed Air by 2016|author=Marc Carter|access-date=30 May 2015}}</ref>

In January 2015, there was disappointing news from France: PSA Peugeot Citroën has putdelayed an indefinite hold onindefinitely the development of its promising-soundingseeming Hybrid Air powertrain, apparently because the company has been unable to find a development partner willing to splitshare the huge costs of engineering the system. Development costs are estimated to 500 million Euros. Production volumes would have to be more than 500,000 cars a year to repay these costs.<ref>{{Cite news|url=https://blog.caranddriver.com/deflated-peugeot-citroen-shelves-its-air-hybrid-technology/|title=Deflated: Peugeot Citroen Shelves Its Air Hybrid Technology|last=Duff|first=Mike|date=January 26, 2015|work=Car and Driver|access-date=2018-10-29|language=en}}</ref> The head of the project left Peugeot in 2014.<ref>{{Cite web|url=https://www.lesechos.fr/11/01/2015/lesechos.fr/0204071426759_psa---la-revolution-de-l-hybrid-air-n-aura-pas-lieu.htm|title=PSA : la révolution de l'Hybrid Air n'aura pas lieu|last=Fansilber|first=Maxime Amiot Denis|date=November 1, 2015|website=Les Echos|language=fr|access-date=2018-10-29}}</ref>