Natural gas vehicle

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"NGV" redirects here. For the art gallery in Melbourne, Australia, see National Gallery of Victoria.

A natural gas vehicle or NGV is an alternative fuel vehicle that uses compressed natural gas (CNG) or, less commonly, liquefied natural gas (LNG) as a clean alternative to other automobile fuels. Worldwide, there are more than 7 million NGVs on the roads as of 2008,[1] with the largest number of NGVs in Argentina, Brazil, Pakistan, Italy, India, China, and Iran,[2] with South America leading with a global market share of 48%.[3] The US has some 130,000, mostly buses.[2] In OECD countries there are around 500,000 CNG vehicles.[4] In some countries, such as Armenia, a large percentage of the fleet has been retro-fitted for bi-fuel operation, reaching between 20 to 30% of the cars on the road.[5]

Existing gasoline-powered vehicles may be converted to allow the use of CNG. An increasing number of vehicles worldwide are being manufactured to run on CNG. The Honda Civic GX is the only NGV commercially available in the US market.[6][7] GM do Brasil introduced the MultiPower engine in August 2004 which was capable of using CNG, alcohol and gasoline (E20-E25 blend) as fuel, and it was used in the Chevrolet Astra 2.0 model 2005, aimed at the taxi market.[8][9] In 2006 the Brazilian subsidiary of FIAT introduced the Fiat Siena Tetra fuel, a four-fuel car developed under Magneti Marelli of Fiat Brazil. This automobile can run on natural gas (CNG); 100% ethanol (E100); E20 to E25 gasoline blend, Brazil's mandatory gasoline; and pure gasoline, though no longer available in Brazil it is used in neighboring countries.[10][11]

Despite its advantages, the use of natural gas vehicles faces several limitations, including fuel storage and infrastructure available for delivery and distribution at gasoline fueling stations. Natural gas must be stored in cylinders, whether it is CNG (compressed) or LNG (liquefied), and these cylinders are usually located in the vehicle's trunk, reducing the space available for other uses, particularly during long distance travel. As with other alternative fuels, natural gas distribution to and at fueling stations, as well as the number of stations selling CNG are other barriers for widespread use of NGVs.[4]

NGV's can be refueled anywhere from existing natural gas lines. This makes home refuelling stations that tap into such lines possible. A company called FuelMaker has pioneered such a system called Phill Home Refueling Appliance (known as "Phill"), which they have developed in partnership with Honda for the American GX model.[12][13]


[edit] Chemical composition and energy content

[edit] Chemical composition

The primary component of natural gas is methane (CH4), the shortest and lightest hydrocarbon molecule. It may also contain heavier gaseous hydrocarbons such as ethane (C2H6), propane (C3H8) and butane (C4H10), as well as other gases, in varying amounts. Hydrogen sulfide (H2S) is a common contaminant, which must be removed prior to most uses.

[edit] Energy content

Combustion of one cubic meter yields 38 MJ (10.6 kWh). Natural gas has the highest energy/carbon ratio of any fossil fuel, and thus produces less carbon dioxide per unit of energy.

[edit] Storage and transport

[edit] Transport

The major difficulty in the use of natural gas is transportation. Natural gas pipelines are economical, but are impractical across oceans. Liquefied natural gas (LNG) tankers are also used.

[edit] Storage

Typical CNG gas tank located in the trunk.

CNG is typically stored in steel or composite containers at high pressure (3000 to 4000 lbf/in², or 205 to 275 bar). These containers are not typically temperature controlled, but are allowed to stay at local ambient temperature.

LNG (Liquefied Natural Gas) storage pressures are typically at or just above the local atmospheric pressure (0 to 30 lbf/in², or 0 to 2.1 bar). LNG is stored at temperatures as low as -260°F (-162°C). At these temperature and pressure conditions, natural gas is in a liquid state. Storage temperatures may vary due to varying composition and storage pressure. LNG is far denser than even the highly compressed state of CNG. As a consequence of the low temperatures, vacuum insulated storage tanks are used to hold LNG. These tanks are often referred to as dewars to credit the early cryogenic scientist Sir James Dewar.

[edit] Implementation

Popular among taxi drivers, the Brazilian Fiat Siena Tetrafuel 1.4, is a multifuel car that runs as a flexible-fuel on pure gasoline, or E20-E25 blend, or pure ethanol (E100); or runs as a bi-fuel with natural gas (CNG). Below: the CNG storage tanks in the trunk.

[edit] South America

CNG vehicles are commonly used in South America, 48% of the world total,[3] where these vehicles are mainly used as taxicabs in main cities of Argentina and Brazil. Normally, standard gasoline vehicles are retrofitted in specialized shops, which involve installing the gas cylinder in the trunk and the CNG injection system and electronics.

Argentina has some 1.69 million NGV's as of 2008, with 1767 refuelling stations across the nation, or 15% of all vehicles.[3] By July 2008 there were 1.56 million retrofitted vehicles in Brazil, or about 5% of the total light vehicle fleet, with 1585 refuelling stations,[3] and a higher concentration in the cities of Rio de Janeiro and São Paulo.[3][8]

Bolivia has increased its fleet from 30,000 in 2004 to 90,163 units in April 2008, Colombia has an NGV fleet of 257,468 vehicles, and 378 refueling stations as of June 2008. Peru has 41,411 NGV as of July 2008, but that number is expected to skyrocket as Peru sits on South America's largest gas reserves.[3]

[edit] Latest developments

GM do Brasil introduced the MultiPower engine in August 2004 which was capable of using CNG, alcohol and gasoline as fuel. The GM engine has electronic fuel injection that automatically adjusts to any acceptable fuel configuration. This motor was used in the Chevrolet Astra and was aimed at the taxi market.[8]

In 2006 the Brazilian subsidiary of FIAT introduced the Fiat Siena Tetra fuel, a four-fuel car developed under Magneti Marelli of Fiat Brazil.[10][14] This automobile can run on 100% ethanol (E100), E20 to E25 blend (Brazil's normal ethanol gasoline blend), pure gasoline (not available in Brazil), and natural gas, and switches from the gasoline-ethanol blend to CNG automatically, depending on the power required by road conditions.[15]

Since 2003 and with the commercial success of flex cars in Brazil, another existing option is to retrofit an ethanol flexible-fuel vehicle to add a natural gas tank and the corresponding injection system. Some taxicabs in São Paulo and Rio de Janeiro, Brazil, run on this option, allowing the user to choose among three fuels (E25, E100 and CNG) according to current market prices at the pump. Vehicles with this adaptation are known in Brazil as tri-fuel cars.[16]

[edit] Southeast Asia

In Malaysia, the use of compressed natural gas was originally introduced for taxicabs and airport limousines during the late-1990s, when new taxis were launched with CNG engines while taxicab operators were encouraged to send in existing taxis for full engine conversions, reducing their costs of operation. Any vehicle converted to use CNG is labelled with white rhombus "NGV" (Natural Gas Vehicle) tags, lending to the common use of "NGV" when referring to road vehicles with CNG engine. The practice of using CNG remained largely confined to taxicabs predominantly in the Klang Valley and Penang due to a lack of interest. No incentives were offered for those besides taxicab owners to use CNG engines, while government subsidies on petrol and diesel made conventional road vehicles cheaper to use in the eyes of the consumers. Petronas, Malaysia's state-owned oil company, also monopolises the provision of CNG to road users. As of July 2008, Petronas only operates about 150 CNG refueling stations, most of which are concentrated in the Klang Valley. At the same time, another 50 was expected by the end of 2008.[17]

As fuel subsidies were gradually removed in Malaysia starting June 5, 2008, the subsequent 41% price hike on petrol and diesel led to a 500% increase in the number of new CNG tanks installed.[18][19] National car maker Proton considered fitting its Waja, Saga and Persona models with CNG kits from Prins Autogassystemen by the end of 2008,[20] while a local distributor of locally assembled Hyundai cars offers new models with CNG kits.[21] Conversion centres, which also benefited from the rush for lower running costs, also perform partial conversions to existing road vehicles, allowing them to run on both petrol or diesel and CNG with a cost varying between RM3,500 to RM5,000 for passenger cars.[22][18]

There were about 400 CNG-fueled vehicles in Singapore in mid-2007, of which about 110 are taxis operated by Smart Automobile. By February 2008, the number has risen 520 CNG vehicles, of which about half are taxies[23]. All vehicles had to refuel at the sole CNG station operated by Sembcorp Gas and located on Jurong Island until the opening of the first publicly accessible CNG station at Mandai in 2008, operated by Smart Automobile[24]. The company plans to build another four stations by 2011, by which time the company projects to operated 3,000 to 4,000 CNG taxies, and with 10,000 CNG public and commercial vehicles of other types on Singapore's roads[25]. Sembcorp Gas opened its second CNG station a week after the Mandai station at Jalan Buroh[23].

Thailand has for over a decade run natural gas taxi cabs in Bangkok. However, conversion in earnest has begun since oil prices have risen, and now thousands of private automobiles and public buses have converted. Natural gas vehicles in Thailand have reached 98,000 in 2008.[26]

[edit] China

China has at year end 2006, 194,860 NGV's and 490 refueling stations.[27] China's national reserves was 134 billion cubic meters at the end of 2007.[citation needed]

[edit] See also

[edit] References

  1. ^ John Lyon (2008-06-04). "65 Million NGVs by 2020 - IANGV Projection". International Association of Natural Gas Vehicles. Retrieved on 2008-10-17.
  2. ^ a b "Pakistan Hits One-Million Natural Gas Vehicle Mark". Green Car Congres (2006-05-13). Retrieved on 2008-10-17. Click on the right side graph to enlarge and see fleet by leading countries
  3. ^ a b c d e f R. Fernandes (2008-08-20). "Latin America NGVs: An Update Report". International Association of Natural Gas Vehicles. Retrieved on 2008-10-11.
  4. ^ a b Ryan, Lisa; Turton, Hal (2007), Sustainable Automobile Transport, Edward Elgar Publishing Ltd, England, pp. 40-41, ISBN 978-1847204516 
  5. ^ Necessity mother of invention in gas-fuelled Armenia
  6. ^ Christine Gable and Scott Gable. "2008 Natural Gas Vehicles (NGVs) Available". Hybrid Cars & Alt Fuels. Retrieved on 2008-10-18.
  7. ^ "2009 Honda Civic GX Natural Gas Vehicle". Honda. Retrieved on 2008-10-18.
  8. ^ a b c GNVNews (November 2006). "Montadores Investem nos Carros á GNV" (in Portuguese). Institutio Brasileiro de Petroleo e Gas. Retrieved on 2008-09-20.
  9. ^ "Astra é líder no segmento dos compactos em 2004: As versões do Chevrolet Astra 2005" (in Portuguese). Journal Express (2005-01-18). Retrieved on 2008-10-15.
  10. ^ a b Christine Lepisto (2006-08-27). "Fiat Siena Tetra Power: Your Choice of Four Fuels". Treehugger. Retrieved on 2008-08-24.
  11. ^ Agência AutoInforme (2006-06-19). "Siena Tetrafuel vai custar R$ 41,9 mil" (in Portuguese). WebMotor. Retrieved on 2008-08-14. The article argues that even though Fiat called it tetra fuel, it actually runs on three fuels: natural gas, ethanol, and gasoline, as Brasilian gasoline is an E20 to E25 blend.
  12. ^ FuelMaker Corporation - World Leader in Convenient On-Site Refueling Systems
  13. ^ EVWORLD FEATURE: Honda's Phill-way to Hydrogen:HONDA | CNG | NATURAL | GAS | CIVIC | GX | PHILL | ELLIS | HYDROGEN | H2
  14. ^ "Nouvelle Fiat Siena 2008: sans complexe" (in French). Caradisiac (2007-11-01). Retrieved on 2008-08-31.
  15. ^ Agência AutoInforme (2006-06-19). "Siena Tetrafuel vai custar R$ 41,9 mil" (in Portuguese). WebMotor. Retrieved on 2008-08-14. The article argues that even though Fiat called it tetra fuel, it actually runs on three fuels: natural gas, ethanol, and gasoline.
  16. ^ TaxiNews. "Gás Natural Veicular" (in Portuguese). Retrieved on 2008-08-24.
  17. ^ "More natural gas stations needed, say motorists". The Star Online (2008-06-13). Retrieved on 2008-08-04.
  18. ^ a b Rashvinjeet S. Bedi (2008-06-08). "Motorists rush to check out NGV system". The Star Online. Retrieved on 2008-08-04.
  19. ^ Vinesh, Derrick (2008-06-25). "Long queue for NGV kits". The Star Online. Retrieved on 2008-08-04.
  20. ^ "Proton cars to come with NGV kits". The Star Online (2008-06-28). Retrieved on 2008-08-04.
  21. ^ Elaine Ang and Leong Hung Yee (2008-07-07). "Moving towards hybrid vehicles". The Star Online. Retrieved on 2008-08-04.
  22. ^ Perumal, Elan (2008-06-13). "Rush to fit natural gas gadget". The Star Online. Retrieved on 2008-08-04.
  23. ^ a b 404 - NGV Global - Alternative Fuel, CNG, NGV, LNG
  24. ^
  25. ^
  26. ^ [1]
  27. ^ [2]

[edit] External links

[edit] Europe

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