Natural gas vehicle
Natural gas vehicles or NGVs are an alternative fuel vehicle that use natural gas which burns cleaner than gasoline or diesel. However, these vehicles aren't as clean as fuel cell vehicles or electric vehicles. NGVs were first manufactured in United States during the 1930s. They were used during World War II in Europe and interest for these vehicles rose during the early 1950s.[1] Today Natural gas refueling stationss are located in five provinces across Canada and are usually found in near proximity of existing retail gasoline station.[2]
In early 1990s, the International Association for Natural Gas Vehicles (IANGV) implemented guidelines for international commercialization of NGVs. Canada’s NGV deployment programs during 1980s and 1990s resulted in a production of 35,000 NGVs.[3] However, Canadian NGVs started to decline after 1995 due to:
- Collapse of world oil prices
- Increased conversion costs due to strict emission requirements
- Decline in Research and Development support
- Limited factory-made NGVs
When comparing natural gas versus other fuels, NGVs usually have:[5]
- Lower cost than gasoline and diesel
- High performance similar to diesel or gasoline powered vehicles
- Secure and long lasting fuel supply
Please see GHGs for AFVs to see how greenhouse gas emissions compare, and comparing gasoline, diesel, natural gas, and electricity prices.
Natural gas vehicle technologies
These lower emission vehicles are available in many types (highway tractors, transit/school buses, off-road, light). Canadian companies offer three types of engine technologies for natural gas vehicles:[2]
| Technology | Description | Type of Vehicle |
|---|---|---|
| Spark Ignited Natural Gas Engine | Engine in which combustion occurs when air-fuel mixture is ignited by spark |
Medium/Heavy Duty Highway Tractor, Bus, Truck |
| Compression Cycle Engine for Natural Gas with Diesel Pilot ignition |
Injection of small amount diesel into engine to trigger combustion by natural gas to achieve higher efficiency |
Heavy Duty Highway Tractor |
| Fuel Injection Conversion Kit | Kits used to retrofit a regular gasoline engine so that the vehicle can also operate using natural gas |
Light Duty Vehicle |
NGVs are available from North American manufacturers such as General Motors (GM) and Ford, and conversion kits are available for existing conventional cars. GM offers full-sized compressed natural gas (CNG) fuelled vans for fleet customers. Ford offers many CNG ready chassis body for aftermarket conversion. Conversion kits are commercially available from Canadian companies (energyeducation.ca has no opinion on these companies).[2]
Natural gas fuels
There are three types of natural gas fuels including compressed, liquefied, and adsorbed natural gas.
- Compressed natural gas (CNG) is stored under high pressure of 3,000 psig to 3,600 psig and historically, being the most attractive natural gas fuel. The high-pressure pose safety concerns in design of these vehicles.[2]
- Liquefied natural gas (LNG) is usually stored at -160°C and is best suited for heavy-duty vehicles and natural gas transportation overseas.[2]
- Adsorbed natural gas is stored at a lower pressure of 500 psig to 600 psig in which natural gas is adsorbed by a porous adsorbent. However, there are some technical challenges, which includes the adsorbent (activated carbon) development or deliverability capacity of the gas from the adsorbent.[6]
Worldwide natural gas vehicle distribution
In 2011, Iran, Pakistan, and Argentina were the top three countries with the most natural gas vehicles, totaling around 15.2 million vehicles globally. Same year, Canada had 14,200 natural gas vehicles with 80 fueling stations. As illustrated in figure 2, the total worldwide natural gas vehicles has grown roughly exponentially since 1991 (about 24% growth per year).
References
- ↑ Random History, “Natural Gas & Transportation The History of Natural Gas Vehicles,” 2008. [Online]. Available: http://www.randomhistory.com/2008/09/08_ngv.html [Accessed on 20 October 2013].
- ↑ 2.0 2.1 2.2 2.3 2.4 Canadian Natural Gas Vehicle Alliance, “Vehicles & Stations,” 2012. [Online]. Available: http://www.cngva.org/en/home/vehicles-stations.aspx [Accessed on 20 October 2013].
- ↑ Natural Gas Use in the Canadian Transportation Sector, “Deployment Roadmap,” 2010. [Online]. Available: http://oee.nrcan.gc.ca/transportation/alternative-fuels/resources/2888 [Accessed on 20 October 2013].
- ↑ EnergyFool. “Alternative Fuels,” 2011. [Online]. Available: http://www.energyfool.com/site/?q=alternative-fuels [Accessed on 20 October 2013].
- ↑ Southern California Gas Company. “Comparing natural gas vs. other fuels,” 2009. [Online]. Available: http://www.socalgas.com/innovation/natural-gas-vehicles/policy/fuel-comparison.shtml[Accessed on 20 October 2013].
- ↑ R.W Judd. “The Use of Adsorbed Natural Gas Technology for Large Scale Storage,” 1992. [Online]. Available: http://web.anl.gov/PCS/acsfuel/preprint%20archive/Files/43_3_BOSTON_08-98_0575.pdf [Accessed on 20 October 2013].
- ↑ NGV Global. “2011 Natural Gas Vehicle Statistics Published,” 2011.http://www.iangv.org/2012/05/2011-natural-gas-vehicle-statistics-released. [Accessed on 21 October 2013]