How Safe are Natural Gas Vehicles?
Natural gas is an environmentally clean, plentiful, low-cost, domestically produced fuel that is used in
more than 70,000,000 homes and businesses throughout the US and as a transportation fuel for
motor vehicles. But is it a safe vehicle fuel?
Any fuel, including those used in motor vehicles, can be dangerous if handled improperly. Fuels
contain energy, which is released when the fuel is ignited. Gasoline is a potentially dangerous fuel, but,
by understanding how to handle it, we have learned to use it safely. The same is true of natural gas.
Natural gas safely generates our electricity, heats our homes and cooks our meals. But, like gasoline,
natural gas must be understood and respected in order to be used safely.
Natural gas is fuel that occurs naturally and requires very little processing before use. Chemically it
normally consists of over 90% methane with smaller amounts of ethane, propane, butane, carbon
dioxide and other trace gases. Pure methane has a very high octane rating (120-130) and the high
methane content of natural gas in turn gives natural gas this same attribute. The low carbon content of
methane also allows for the potential of low carbon and green house gas emissions
As with all vehicle fuels, natural gas can be used safely if the unique properties of the fuel are
understood and common sense procedures are followed. In fact, natural gas has safety advantages
compared to gasoline and diesel: it is non-toxic, and has no potential for ground or water
contamination in the event of a fuel release. Natural gas is lighter than air and dissipates rapidly when
released. An odorant is added to provide a distinctive and intentionally disagreeable smell that is easy
to recognize. The odor is detectable at one-fifth of the gas’ lower flammability limit.
Natural gas vehicles have an excellent safety record for two primary reasons: the properties of the
fuel itself and the integrity of the natural gas vehicle and its fuel delivery system.
Natural gas has a very limited range of flammability – it will not burn in concentrations below about 5%
or above about 15% when mixed with air. Gasoline and diesel burn at much lower concentrations and
ignite at lower temperatures. Although it takes very little energy to ignite a flammable mixture of air
and natural gas, gasoline, or diesel, natural gas burns at a somewhat lower temperature.
2
Source: Murphy, Michael J., Properties of Alternative Fuels, Federal Transit Administration, 1994
From the gas field to the vehicle’s engine, natural gas requires very little processing to make it suitable
for use as a fuel. Gasoline and diesel must be processed from crude oil in large and complex oil
refineries. After water vapor, sulfur and heavy hydrocarbons are removed, natural gas flows by pipeline
(the safest way to transport energy) directly to the fueling station where it is compressed for use.
Alternatively it may be used as Liquefied Natural Gas (LNG) by being cooled to cryogenic temperatures
on site or at a central facility and delivered by truck. Gasoline and diesel are delivered to fueling
stations by tank trucks over the highway.
At a compressed natural gas fueling station the gas is compressed before being provided to vehicles
at 3000 to 3600 pounds per square inch (psi). Stations can deliver a “fast fill” to vehicles in minutes
or, using a “slow fill” strategy, in a few hours to overnight.
Although the use of high storage pressures might appear dangerous, compression, storage and fueling
of natural gas vehicles meet stringent industry and government safety standards. Remember that highpressure
gases are used safely every day in industrial and medical applications.
Natural gas powered vehicles are designed and built to be safe both in normal operation and in
accidents. New OEM natural gas vehicles are subjected to the same federal government crash tests
as other vehicles. OEM natural gas vehicle fuel systems must meet Federal Motor Vehicle Safety
Standards 303 and 304. Natural gas cylinders are much thicker and stronger than gasoline or diesel
tanks. Cylinders are designed not to rupture when fully fueled over six times a day, 365 days a year,
far beyond what they will see in service. Industry standards test them far beyond normal
environmental and service damage risks. Cylinders must even withstand a bonfire test and
penetration by a 30-caliber bullet without rupture! The cylinders are designed for a specific lifetime
from 15 up to 25 years and are required to be inspected every 3 years or 36,000 miles.
No matter what the fuel, fueling stations, indoor parking structures and repair garages must be built to
ensure high levels of safety. Again recognizing the unique requirements for facilities handling natural
gas and natural gas vehicles will differ from those for gasoline or diesel vehicles. For example, leaking
diesel and gasoline form puddles on the floor. Natural gas normally rises toward the ceiling and
disperses. Therefore the danger of fire would be greatest near the floor for liquid fuels and near the
ceiling for natural gas.
Data collected over time has demonstrated natural gas vehicles to be safe in actual operation. Based
on a survey of 8,331 natural gas utility, school, municipal and business fleet vehicles (NGVs) that
traveled
178.3 million miles:
• The NGV fleet vehicle injury rate was 37% lower than the gasoline fleet vehicle rate.
Property Natural Gas Gasoline Diesel
Flammability Limits (volume % in air) 5-15 1.4-7.6 0.6-5.5
Autoignition Temperature (°F) 842 572 446
Minimum Ignition Energy in Air (10-6 BTU) 0.27 0.23 0.23
Peak Flame Temperature (°F) 3423 3591 3729
• There were no fatalities compared with 1.28 deaths per 100 million miles for gasoline fleet
vehicles The collision rate for NGV fleet vehicles was 31% lower than the rate for gasoline fleet vehicles
• The fleet of 8,331 NGVs was involved in seven fire incidents, only one of which was directly
attributable to failure of the natural gas fuel system.
Natural gas vehicles were first commercialized after World War II in Italy. There are now over twelve
million in use worldwide. Natural gas vehicles have been used in the US since the early 1970s, with
over 120,000 in use today. Yet there has been only one fatality in the US involving a NGV in all that
time and it was attributed to human error.
Even more important than statistics is the confidence that natural gas vehicle users feel. One in five
new transit buses are natural gas powered, with about 12,000 transit buses and community shuttles in
service. Police in Rocky Hill, CT report “the safety record of the (NGV) cars has been excellent.” The
Department of Energy states that “after rigorous testing… (the King County, Washington police) found
their… (Compressed Natural Gas) cars to be as safe and reliable as conventional vehicles”
Not only are transit agencies and police using natural gas vehicles, more and more school buses are
now powered by natural gas. The Department of Energy worked with a major school bus supplier to
develop “an ultra-safe and low-emission” natural gas powered school bus. School buses from that
manufacturer and others, using natural gas engines , are in widespread use today with over 3,000 in
service.
How do natural gas vehicles behave in crashes? The strength of the natural gas cylinders and fuel
system generally avoids any leakage or fire. For example an accident involving a CNG-powered pickup…
proved to be a testimonial to the safety of CNG tanks. As reported in the May 1995 edition of
Automotive Fleet:
When the 1992 CNG pick-up was broadsided in Midland, Texas, the most vulnerable part of the
fueling system bore the brunt of the hit. While the force drove an imprint of the tank safety valve into
the side of the truck, the CNG tanks did not rupture, and driver Jimmy Oden walked away.
And in a tragic 1998 accident, a stopped bi-fueled Honda (a vehicle which could run on either natural
gas or gasoline) was impacted by another vehicle moving at nearly 100 mph and a fire fed by gasoline
broke out. The 50-liter natural gas fuel tank was intact and remained secured in its support brackets.
(Reported in a June 1998 BC Gas press release).
Nationwide Insurance, in looking at the safety of natural gas buses in a fleet, concluded as long ago as
1992 that “…the natural gas powered vehicles will be the safest vehicles in your fleet and (we) have no
reservations about insuring them.” (Palmer, Pat, Nationwide Insurance, letter to Kenneth E. Bauman
Bus, Inc., September 10, 1992)
In summary, technical data, appropriate safety regulations and years of experience show natural gas
vehicles to be as safe as, or safer than, conventionally fueled vehicles.
Τρίτη 19 Απριλίου 2011
what is cng
Compressed natural gas (CNG) is a fossil fuel substitute for gasoline (petrol), diesel, or propane/LPG. Although its combustion does produce greenhouse gases, it is a more environmentally clean alternative to those fuels, and it is much safer than other fuels in the event of a spill (natural gas is lighter than air, and disperses quickly when released). CNG may also be mixed with biogas, produced from landfills or wastewater, which doesn't increase the concentration of carbon in the atmosphere.
CNG is made by compressing natural gas (which is mainly composed of methane [CH4]), to less than 1% of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of 200–248 bar (2900–3600 psi), usually in cylindrical or spherical shapes.
CNG is used in traditional gasoline internal combustion engine cars that have been converted into bi-fuel vehicles (gasoline/CNG). Natural gas vehicles are increasingly used in the Asia-Pacific region, Latin America, Europe, and America due to rising gasoline prices.[1] In response to high fuel prices and environmental concerns, CNG is starting to be used also in tuk-tuks and pickup trucks, transit and school buses, and trains.
CNG's volumetric energy density is estimated to be 42% of LNG's (because it is not liquefied), and 25% of diesel's.[2]Contents [hide]
1 Technology
2 Drawbacks
3 CNG cars
4 CNG Advantage
5 CNG Locomotives
6 CNG compared to LNG
7 Worldwide
7.1 South Asia
7.2 South America
7.3 South-East Asia
7.4 Middle East and Africa
7.5 Europe
7.6 North America
7.6.1 Canada
7.6.2 United States of America
7.7 Oceania
8 References
[edit]
Technology
A CNG powered high-floor Neoplan AN440A, operated by ABQ RIDE in Albuquerque, New Mexico.
CNG can be used in Otto-cycle (gasoline) and modified Diesel cycle engines.
[edit]
Drawbacks
CNG pumps at a Brazilian gasoline fueling station
CNG powered bus in Madrid (Spain).
Gas storage in a car.
Compressed natural gas vehicles require a greater amount of space for fuel storage than conventional gasoline powered vehicles. Since it is a compressed gas, rather than a liquid like gasoline, CNG takes up more space for each gasoline gallon equivalent (GGE). Therefore, the tanks used to store the CNG usually take up additional space in the trunk of a car or bed of a pickup truck which runs on CNG. This problem is solved in factory-built CNG vehicles that install the tanks under the body of the vehicle, thanks to a more rational disposition of components, leaving the trunk free (e.g. Fiat Multipla, New Fiat Panda, Volkswagen Touran Ecofuel, Volkswagen Caddy Ecofuel, Chevy Taxi (sold in countries such as Peru)). Another option is installation on roof (typical on buses), requiring, however, solution of structural strength issues. CNG-powered vehicles are considered to be safer than gasoline-powered vehicles.[3][4][5]
[edit]
CNG cars
Main article: Natural gas vehicle
Worldwide, there were 11.2 million natural gas vehicles by 2009, led by Pakistan with 2.5 million, Argentina (1.8 million), Iran (1.7 million), Brazil (1.6 million), and India (725 thousand).[1] with the Asia-Pacific region leading with 5.7 million NGVs, followed by Latin America with almost 4 million vehicles.[1]
CNG cars available in Europe are bi-fuel vehicles burning one fuel at a time. Their engine is a standard gasoline internal combustion engine (ICE). This means that they can indifferently run on either gasoline from a gasoline tank or CNG from a separate cylinder in the trunk. The driver can select what fuel to burn by simply flipping a switch on the dashboard.
Several manufacturers (Fiat, Opel(General Motors), Peugeot, Volkswagen, Toyota, Honda and others) sell bi-fuel cars. In 2006, Fiat introduced the Siena Tetrafuel in the Brazilian market, equipped with a 1.4L FIRE engine that runs on E100, E25 (Standard Brazilian Gasoline), Gasoline and CNG.
Any existing gasoline vehicle can be converted to a bi-fuel (gasoline/CNG) vehicle. Authorized shops can do the retrofitting, this involves installing a CNG cylinder in the trunk, installing the plumbing, installing a CNG injection system and the electronics.
[edit]
CNG Advantage
Due to the absence of any lead or benzene content in CNG, the lead fouling of spark plugs is eliminated. CNG-powered vehicles have lower maintenance costs when compared with other fuel-powered vehicles. CNG fuel systems are sealed, which prevents any spill or evaporation losses. Another practical advantage observed is the increased life of lubricating oils, as CNG does not contaminate and dilute the crankcase oil. CNG mixes easily and evenly in air being a gaseous fuel. CNG is less likely to auto-ignite on hot surfaces, since it has a high auto-ignition temperature (540 °C) and a narrow range (5%-15%) of flammability.[6]
CNG emits significantly less pollutants such as carbon dioxide (CO2), hydrocarbons (UHC), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and particulate matter (PM), compared to petrol. For example, an engine running on petrol for 100 km emits 22,000 grams of CO2, while covering the same distance on CNG emits only 16,275 grams of CO2. [CNG is essentially methane, i.e. CH4 with a calorific value of 900 Kj/mol. This burns with Oxygen to produce 1 mol of CO2 and 2 mol of H2O. By comparison, petrol can be regarded as essentially Benzene or similar, C6H6 with a calorific value of about 3,300 Kj/mol and this burns to produce 6 mol of CO2 and 3 mol of H2O. From this it can be seen that per mol of CO2 produced, CNG releases over 1.6 times as much energy as that released from petrol (or for the same amount of energy, CNG produces nearly 40% less CO2).] The corresponding figures are 78 and 25.8 grams respectively, for nitrogen oxides. Carbon monoxide emissions are reduced even further. Due to lower carbon dioxide and nitrogen oxides emissions, switching to CNG can help mitigate greenhouse gas emissions.[6] The ability of CNG to reduce greenhouse gas emissions over the entire fuel lifecycle will depend on the source of the natural gas and the fuel it is replacing. The lifecycle greenhouse gas emissions for CNG compressed from California's pipeline natural gas is given a value of 67.70 grams of CO2-equivalent per megajoule (gCO2e/MJ) by the California Air Resources Board (ARB), approximately 28% lower than the average gasoline fuel in that market (95.86 gCO2e/MJ). CNG produced from landfill biogas was found by ARB to have the lowest greenhouse gas emissions of any fuel analyzed, with a value of 11.26 gCO2e/MJ (over 88% lower than conventional gasoline) in the low-carbon fuel standard that went into effect on January 12, 2010.[7]
[edit]
CNG Locomotives
CNG Locomotives are operated by several railroads. The Napa Valley Wine Train successfully retrofit a diesel locomotive to run on compressed natural gas before 2002.[8] This converted locomotive was upgraded to utilize a computer controlled fuel injection system in May 2008, and is now the Napa Valley Wine Train's primary locomotive.[9] Ferrocarril Central Andino in Peru, has run a CNG Locomotive on a freight line since 2005[10] CNG locomotives are usually diesel locomotives that have been converted to use compressed natural gas generators instead of diesel generators to generate the electricity that drives the motors of the train. Some CNG locomotives are able to fire their cylinders only when there is a demand for power, which, theoretically, gives them a higher fuel efficiency than conventional diesel engines. CNG is also cheaper than petrol or diesel.
[edit]
CNG compared to LNG
CNG is often confused with liquefied natural gas (LNG). While both are stored forms of natural gas, the key difference is that CNG is gas that is stored (as a gas) at high pressure, while LNG is in uncompressed liquid form. CNG has a lower cost of production and storage compared to LNG as it does not require an expensive cooling process and cryogenic tanks. CNG requires a much larger volume to store the same mass of gasoline or petrol and the use of very high pressures (3000 to 4000 psi, or 205 to 275 bar).
CNG can be stored at lower pressure in a form known as an ANG (Adsorbed Natural Gas) tank, at 35 bar (500 psi, the pressure of gas in natural gas pipelines) in various sponge like materials, such as activated carbon[11] and metal-organic frameworks (MOFs).[12] The fuel is stored at similar or greater energy density than CNG. This means that vehicles can be refuelled from the natural gas network without extra gas compression, the fuel tanks can be slimmed down and made of lighter, less strong materials.
[edit]
Worldwide
[edit]
South Asia
A Taxicab in New Delhi. A 1998 court order requires local buses and autos in Delhi to run on Compressed Natural Gas
Pakistan currently has the highest number of vehicles running on CNG in the world followed by Argentina, Brazil and Iran. Pakistan also has the highest number of CNG stations in the world numbering more than 3600. Majority of private vehicles have converted to CNG because of cheaper price as compared to petrol. Only luxury cars and official vehicles now run on petrol. Recently, new CNG Buses had been introduced by CDGK in Karachi. Almost all car manufacturers in Pakistan (except Honda) now produce company fitted CNG kit versions. Recent hikes in CNG prices has downplayed the ambitious ventures of some of the stakeholders in this sector. It is expected that price of the CNG and Kits will come down as competition among manufacturers grows. LandiRenzo Pakistan is also exporting CNG kits to various countries including China, Brazil and Italy. Almost 2 million vehicles on the country's roads have dual fuel options with Suzuki having the highest in quantity.
CNG has grown into one of the major fuel sources used in car engines in India and Bangladesh as well. The use of CNG is mandated for the public transport system of India's capital New Delhi as well as for the city of Ahmedabad in the state of Gujarat. The Delhi Transport Corporation operates the world's largest fleet of CNG buses. Today many rickshaws as well as personal vehicles in India and Bangladesh are being converted to CNG powered technology, the cost of which is in the range of $800–$1000. In the Bangladesh capital of Dhaka not a single auto rickshaw without CNG has been permitted since 2003.[13]
In India CNG costs are at Rs. Rs 29.00 per kg (US$0.85 ) per kg compared with Rs. 59.00 (US$ 1.721) per liter of petrol (prices as of Feb. 2011 in Delhi, India). In Thailand CNG costs are at Thb 10.4 per kg (US$0.35) per kg compared with Thb 40.00 (US$ 1.35) per liter of petrol (prices as of Mar. 2011 in Bangkok, Thailand). CNG is quite notable at a cost savings of 60% along with reduced emissions and its usability by environmentally friendlier cars.
[edit]
South America
CNG station in Rosario, Argentina.
CNG vehicles are commonly used in South America, where these vehicles are mainly used as taxicabs in main cities of Argentina and Brazil.[14] 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 and Brazil are the two countries with the largest fleets of CNG vehicles,[14] with a combined total fleet of more than 3.4 million vehicles by 2009.[1] Conversion has been facilitated by a substantial price differential with liquid fuels, locally produced conversion equipment and a growing CNG-delivery infrastructure.
As of 2009 Argentina had 1,807,186 NGV's with 1,851 refueling stations across the nation,[1] or 15% of all vehicles;[14] and Brazil had 1,632,101 vehicles and 1,704 refueling stations,[1] with a higher concentration in the cities of Rio de Janeiro and São Paulo.[14][15]
Colombia had an NGV fleet of 300,000 vehicles, and 460 refueling stations as of 2009.[1] Bolivia has increased its fleet from 10,000 in 2003 to 121,908 units in 2009, with 128 refueling stations.[1] Peru had 81,024 NGVs and 94 fueling stations as 2009,[1] but that number is expected to skyrocket as Peru sits on South America's largest gas reserves.[14] In Peru several factory-built NGVs have the tanks installed under the body of the vehicle, leaving the trunk free. Among the models built with this feature are the Fiat Multipla, the newFiat Panda, the Volkswagen Touran Ecofuel, the Volkswagen Caddy Ecofuel, and the Chevy Taxi. Other countries with significant NGV fleets are Venezuela (15,000) and Chile (8,064) as of 2009.[1]
[edit]
South-East Asia
A CNG powered Volvo B10BLE bus, operated by SBS Transit in Singapore.
In Singapore CNG is increasingly being used by public transport vehicles like buses and taxis, as well as goods vehicles. However, according to Channel NewsAsia on April 18, 2008, more owners of private cars in this country are converting their petrol-driven vehicles to also run on CNG – motivated no doubt by rising petrol prices. The initial cost of converting a regular vehicle to dual fuel at the German conversion workshop of C. Melchers, for example, is around S$3,800 (US$2,500); with the promise of real cost-savings that dual-fuel vehicles bring over the long term.
Singapore currently has five operating filling stations for natural gas. SembCorp Gas Pte Ltd runs the station on Jurong Island, and jointly with Singapore Petroleum Company, the filling station at Jalan Buroh. Both these stations are in the western part of the country. Another station on the mainland is in Mandai Link to the north and is operated by SMART Energy. SMART also own a second station on Serangoon North Ave 5 which was set up end of March 2009; The fifth and largest station in the world was opened by the UNION Group in September 2009. This station is recognized by the Guniness World Records as being the laregst in the world with 46 refuelling hoses. This station is located in Toh Tuck. The Union Group, which operates 1000 CNG Toyota Wish taxis plan to introduce another 3 daughter stations and increase the CNG taxi fleet to 8000 units.
As a key incentive for using this eco-friendly fuel Singapore has a Green Vehicle Rebate (GVR) for users of CNG technology. First introduced in January 2001, the GVR grants a 40% discount on the Open Market Value (OMV) cost of newly registered green passenger vehicles. This initiative will end at the end of 2012 as the government believes the 'critical mass' of CNG vehicles would then have been built up.
The Ministry of Transport of Myanmar passed a law in 2005 which required that all public transport vehicles - buses, trucks and taxis, be converted to run on CNG. The Government permitted several private companies to handle the conversion of existing diesel and petrol cars, and also to begin importing CNG variants of buses and taxis. Accidents and rumours of accidents, partly fueled by Myanmar's position in local hydrocarbon politics,[16] has discouraged citizens from using CNG vehicles, although now almost every taxi and public bus in Yangon, Myanmar's largest city, run on CNG. CNG stations have been set up around Yangon and other cities, but electricity shortages mean that vehicles may have to queue up for hours to fill their gas containers.[17] The Burmese opposition movements are against the conversion to CNG, as they accuse the companies as being proxies of the junta, and also that the petrodollars earned by the regime would go towards the defense sector, rather than towards improving the infrastructure or welfare of the people.
In Malaysia, the use of CNG 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. 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.[18]
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.[19][20] National car maker Proton considered fitting its Waja, Saga and Persona models with CNG kits from Prins Autogassystemen by the end of 2008,[21] while a local distributor of locally assembled Hyundai cars offers new models with CNG kits.[22] 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.[19][23]
In China, companies such as Sino-Energy are active in expanding the footprint of CNG filling stations in medium-size cities across the interior of the country, where at least two natural gas pipelines are operational.[citation needed]
In India, the Delhi government,in 2004 made it mandatory for all city buses and auto rickshaws to run on CNG with the intention of reducing air pollution
[edit]
Middle East and Africa
Egypt is a top ten country in the world with more than 128,754CNG vehicles and 124 fueling stations nationwide. Egypt was also the first nation in Africa and the Middle East to open a public CNG fueling station in January 1996.[24]
In lion CNG equipped vehicles on the road. There is also a government mandate that forces local car manufacturers to produce 60% of all their new vehicles as dual fuel vehicles.
The vast majority 780000 have been produced as dual fuel vehicles by the auto manufacturer in the last two years, and the remainder have been converted utilizing after market conversion kits in workshops. There are 750 active refueling stations country wide with an additional 660 refueling stations under construction and expected to come on stream. Currently the major problem facing the industry as a whole is the building of refueling stations that is lagging behind dual fuel vehicle production, forcing many to use petrol instead.
In Turkey, Ankara has 1050 CNG buses.
[edit]
Europe
CNG powered bus in Italy
The use of methane (CNG) for vehicles in Italy started in the 1930s and has continued off and on until today. Since 2008 there have been a large market expansion for natural gas vehicles (CNG and LPG) caused by the rise of gasoline prices and by the need to reduce air pollution emissions.[25]
Before 1995 the only way to have a CNG-powered car was by having the retrofitted with an after-market kit. A large producer was Landi Renzo, Tartarini Auto, Prins Autogassystemen, OMVL, BiGAs,... and AeB for electronic parts used by the most part of kit producer.
Landi Renzo and Tartarini have divisions selling vehicles in Asia and South America.
After 1995 bi-fuel cars (gasoline/CNG) became available from several major manufacturers. Currently Fiat, Opel, Volkswagen, Citroen, Renault, Volvo and Mercedes sell various car models and small trucks that are gasoline/CNG powered. Usually CNG parts used by major car manufacturers are actually produced by automotive aftermarket kit manufacturers, e.g. Fiat use Tartarini Auto components, Volkswagen use Teleflex GFI[26] and Landi Renzo components.
In Italy, there are more than 800 CNG stations.[27] In Germany, CNG-generated vehicles are expected to increase to two million units of motor-transport by the year 2020. The cost for CNG fuel is between 1/3 and 1/2 compared to other fossil fuels in Europe.[citation needed] in 2008 there are around 800 gas(CNG) stations in Germany
In Portugal there are 4 CNG refueling stations but 3 of them do not sell to the public. Only in Braga you can find it on the local city bus station (TUB).
In Bulgaria, there are 82 CNG refuelling stations as of June 2010. One can be found in most of Bulgaria's big towns [28] - there are quite a few in Sofia, Plovdiv and Stara Zagora, as well as in the cities on the Black Sea - Varna, Burgas, Nessebar and Kavarna. CNG vehicles are becoming more and more popular in the country. The fuel is used by most taxi drivers because of its much lower price compared to petrol. It is useful to know that CNG stations in Bulgaria operate with the Italian standard nozzle typical for Eastern Europe and not with the NGV1 nozzle used in Germany, Austria, France, Belgium and other European countries.
In Republic of Macedonia, there is one CNG station located in the capital Skopje, but it is not for public use. Only twenty buses of the local Public Transport Company have been fitted to use a mixture of diesel and CNG. The first commercial CNG station in Skopje is in the advanced stage of development and is expected to start operation in July of 2011.
In Serbia, there are 4 public CNG refuelling station in the capital Beograd and near the towns of Pančevo, Kruševac and Čačak. Italian standard nozzle is used in all of them.
In Croatia, there is only one CNG station situated close to the center of Zagreb, Italian-type refuelling nozzle is used there as well.[29] At least 60 CNG buses are in use as a form of a public transport (Zagreb public transport services).
In Sweden there are currently 90 CNG filling stations available to the public (as compared to about 10 LPG filling stations), primarily located in the southern and western parts of the country as well the Mälardalen region[30] Another 70-80 CNG filling stations are under construction or in a late stage of planning (completions 2009-2010). Several of the planned filling stations are located in the northern parts of the country, which will greatly improve the infrastructure for CNG car users.[31] There are approx. 14,500 CNG vehicles in Sweden (2007), of which approx. 13,500 are passenger cars and the remainder includes buses and trucks.[32] In Stockholm, the public transportation company SL currently operates 50 CNG buses but have a capacity to operate 500.[33] The Swedish government recently prolonged its subsidies for the development of CNG filling stations, from 2009-12-31 to 2010-12-31.[34] In Spain the EMT Madrid bus service use CNG motors in 351 regular buses. Is rare to see another kind of CNG vehicle, and there's no CNG refueling stations.
As of 2010, there are 25 public CNG filling stations in the Czech republic, mainly in the big cities.[35] Local bus manufacturers SOR Libchavy and Tedom produce CNG versions of their vehicles, with roof-mounted tanks.
[edit]
North America
The Honda Civic GX is factory-built to run on CNG and it is available in several U.S. regional markets.
Buses powered with CNG are common in the United States.
[edit]
Canada
Canada is a large producer of natural gas, so it follows that CNG is used in Canada as an economical motor fuel. Canadian industry has developed CNG-fueled truck and bus engines, CNG-fueled transit buses, and light trucks and taxis. Both CNG and propane refueling stations are not difficult to find in major centres.
[edit]
United States of America
In the US, federal tax credits are available for buying a new CNG vehicle. Use of CNG varies from state to state, only 34 states have at least one CNG fueling site.[36] In California, CNG is used extensively in local city and county fleets, as well as public transportation (city/school buses), and there are 90 public fueling stations in Southern California alone. Compressed natural gas is available at 30-60% less than the cost of gasoline, as a rule of thumb, in much of California. Personal use of CNG is a small niche market currently, though with current tax incentives and a growing number of public fueling stations available, it is experiencing unprecedented growth. The state of Utah offers a subsidised statewide network of CNG filling stations at a rate of $0.85/gge,[37] while gasoline is above $4.00/gal. Elsewhere in the nation, retail prices average around $2.50/gge, with home refueling units compressing gas from residential gas lines for approx $1.50/gge. Other than aftermarket conversions, and government used vehicle auctions, the only currently produced CNG vehicle in the US is the Honda Civic GX sedan, which is made in limited numbers and available only in a few states.
An initiative, known as Pickens Plan, calls for the expansion of the use of CNG as a standard fuel for heavy vehicles has been recently started by oilman and entrepreneur T. Boone Pickens. California voters defeated Proposition 10 in the 2008 General Election by a significant (59.8% to 40.2%) margin. Proposition 10 was a $5 Billion bond measure that, among other things, would have given rebates to state residents that purchase CNG vehicles.
Congress has encouraged conversion of cars to CNG with a tax credits of up to 50% of the auto conversion cost and the CNG home filling station cost. However, while CNG is much cleaner fuel, the conversion requires a type certificate from the EPA. Meeting the requirements of a type certificate can cost up to $50,000.
[edit]
Oceania
K230UB CNG bus currently used as part of the "Scania Koala CNG Bus Trial" at ACTION in Canberra.
During the 1970s and 1980s, CNG was commonly used in New Zealand in the wake of the oil crises, but fell into decline after petrol prices receded. At the peak of natural gas use, 10 percent of New Zealand's cars were converted, around 110,000 vehicles.[38]
A Mercedes-Benz OC500LE (with Custom Coaches bodywork) running on CNG, operated by Sydney Buses in Sydney, Australia.
Brisbane Transport and Transperth in Australia have both adopted a policy of purchasing only CNG buses in future. Transperth is purchasing 451 Mercedes-Benz OC500LE buses and is undertaking trials with articulated CNG buses from Scania, MAN, and Irisbus, while Brisbane Transport has purchased 216 Scania L94UB and 240 MAN 18.310 models as well as 30 MAN NG 313 articulated CNG buses. The State Transit Authority of New South Wales (operating under the name "Sydney Buses") operates 102 Scania L113CRB buses, two Mercedes-Benz O405 buses and 300 Mercedes-Benz O405NH buses and are now taking delivery of 255 Euro 5-compliant Mercedes-Benz OC500LEs.[39]
In the 1990s Benders Busways of Geelong, Victoria trialled CNG buses for the Energy Research and Development Corporation.[40]
Martin Ferguson, Ollie Clark, and Noel Childs featured on ABC 7.30 Report raising the issue of CNG as an overlooked transport fuel option in Australia, highlighting the large volumes of LNG currently being exported from the North West Shelf in light of the cost of importing crude oil to Australia.[41]
CNG is made by compressing natural gas (which is mainly composed of methane [CH4]), to less than 1% of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of 200–248 bar (2900–3600 psi), usually in cylindrical or spherical shapes.
CNG is used in traditional gasoline internal combustion engine cars that have been converted into bi-fuel vehicles (gasoline/CNG). Natural gas vehicles are increasingly used in the Asia-Pacific region, Latin America, Europe, and America due to rising gasoline prices.[1] In response to high fuel prices and environmental concerns, CNG is starting to be used also in tuk-tuks and pickup trucks, transit and school buses, and trains.
CNG's volumetric energy density is estimated to be 42% of LNG's (because it is not liquefied), and 25% of diesel's.[2]Contents [hide]
1 Technology
2 Drawbacks
3 CNG cars
4 CNG Advantage
5 CNG Locomotives
6 CNG compared to LNG
7 Worldwide
7.1 South Asia
7.2 South America
7.3 South-East Asia
7.4 Middle East and Africa
7.5 Europe
7.6 North America
7.6.1 Canada
7.6.2 United States of America
7.7 Oceania
8 References
[edit]
Technology
A CNG powered high-floor Neoplan AN440A, operated by ABQ RIDE in Albuquerque, New Mexico.
CNG can be used in Otto-cycle (gasoline) and modified Diesel cycle engines.
[edit]
Drawbacks
CNG pumps at a Brazilian gasoline fueling station
CNG powered bus in Madrid (Spain).
Gas storage in a car.
Compressed natural gas vehicles require a greater amount of space for fuel storage than conventional gasoline powered vehicles. Since it is a compressed gas, rather than a liquid like gasoline, CNG takes up more space for each gasoline gallon equivalent (GGE). Therefore, the tanks used to store the CNG usually take up additional space in the trunk of a car or bed of a pickup truck which runs on CNG. This problem is solved in factory-built CNG vehicles that install the tanks under the body of the vehicle, thanks to a more rational disposition of components, leaving the trunk free (e.g. Fiat Multipla, New Fiat Panda, Volkswagen Touran Ecofuel, Volkswagen Caddy Ecofuel, Chevy Taxi (sold in countries such as Peru)). Another option is installation on roof (typical on buses), requiring, however, solution of structural strength issues. CNG-powered vehicles are considered to be safer than gasoline-powered vehicles.[3][4][5]
[edit]
CNG cars
Main article: Natural gas vehicle
Worldwide, there were 11.2 million natural gas vehicles by 2009, led by Pakistan with 2.5 million, Argentina (1.8 million), Iran (1.7 million), Brazil (1.6 million), and India (725 thousand).[1] with the Asia-Pacific region leading with 5.7 million NGVs, followed by Latin America with almost 4 million vehicles.[1]
CNG cars available in Europe are bi-fuel vehicles burning one fuel at a time. Their engine is a standard gasoline internal combustion engine (ICE). This means that they can indifferently run on either gasoline from a gasoline tank or CNG from a separate cylinder in the trunk. The driver can select what fuel to burn by simply flipping a switch on the dashboard.
Several manufacturers (Fiat, Opel(General Motors), Peugeot, Volkswagen, Toyota, Honda and others) sell bi-fuel cars. In 2006, Fiat introduced the Siena Tetrafuel in the Brazilian market, equipped with a 1.4L FIRE engine that runs on E100, E25 (Standard Brazilian Gasoline), Gasoline and CNG.
Any existing gasoline vehicle can be converted to a bi-fuel (gasoline/CNG) vehicle. Authorized shops can do the retrofitting, this involves installing a CNG cylinder in the trunk, installing the plumbing, installing a CNG injection system and the electronics.
[edit]
CNG Advantage
Due to the absence of any lead or benzene content in CNG, the lead fouling of spark plugs is eliminated. CNG-powered vehicles have lower maintenance costs when compared with other fuel-powered vehicles. CNG fuel systems are sealed, which prevents any spill or evaporation losses. Another practical advantage observed is the increased life of lubricating oils, as CNG does not contaminate and dilute the crankcase oil. CNG mixes easily and evenly in air being a gaseous fuel. CNG is less likely to auto-ignite on hot surfaces, since it has a high auto-ignition temperature (540 °C) and a narrow range (5%-15%) of flammability.[6]
CNG emits significantly less pollutants such as carbon dioxide (CO2), hydrocarbons (UHC), carbon monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx) and particulate matter (PM), compared to petrol. For example, an engine running on petrol for 100 km emits 22,000 grams of CO2, while covering the same distance on CNG emits only 16,275 grams of CO2. [CNG is essentially methane, i.e. CH4 with a calorific value of 900 Kj/mol. This burns with Oxygen to produce 1 mol of CO2 and 2 mol of H2O. By comparison, petrol can be regarded as essentially Benzene or similar, C6H6 with a calorific value of about 3,300 Kj/mol and this burns to produce 6 mol of CO2 and 3 mol of H2O. From this it can be seen that per mol of CO2 produced, CNG releases over 1.6 times as much energy as that released from petrol (or for the same amount of energy, CNG produces nearly 40% less CO2).] The corresponding figures are 78 and 25.8 grams respectively, for nitrogen oxides. Carbon monoxide emissions are reduced even further. Due to lower carbon dioxide and nitrogen oxides emissions, switching to CNG can help mitigate greenhouse gas emissions.[6] The ability of CNG to reduce greenhouse gas emissions over the entire fuel lifecycle will depend on the source of the natural gas and the fuel it is replacing. The lifecycle greenhouse gas emissions for CNG compressed from California's pipeline natural gas is given a value of 67.70 grams of CO2-equivalent per megajoule (gCO2e/MJ) by the California Air Resources Board (ARB), approximately 28% lower than the average gasoline fuel in that market (95.86 gCO2e/MJ). CNG produced from landfill biogas was found by ARB to have the lowest greenhouse gas emissions of any fuel analyzed, with a value of 11.26 gCO2e/MJ (over 88% lower than conventional gasoline) in the low-carbon fuel standard that went into effect on January 12, 2010.[7]
[edit]
CNG Locomotives
CNG Locomotives are operated by several railroads. The Napa Valley Wine Train successfully retrofit a diesel locomotive to run on compressed natural gas before 2002.[8] This converted locomotive was upgraded to utilize a computer controlled fuel injection system in May 2008, and is now the Napa Valley Wine Train's primary locomotive.[9] Ferrocarril Central Andino in Peru, has run a CNG Locomotive on a freight line since 2005[10] CNG locomotives are usually diesel locomotives that have been converted to use compressed natural gas generators instead of diesel generators to generate the electricity that drives the motors of the train. Some CNG locomotives are able to fire their cylinders only when there is a demand for power, which, theoretically, gives them a higher fuel efficiency than conventional diesel engines. CNG is also cheaper than petrol or diesel.
[edit]
CNG compared to LNG
CNG is often confused with liquefied natural gas (LNG). While both are stored forms of natural gas, the key difference is that CNG is gas that is stored (as a gas) at high pressure, while LNG is in uncompressed liquid form. CNG has a lower cost of production and storage compared to LNG as it does not require an expensive cooling process and cryogenic tanks. CNG requires a much larger volume to store the same mass of gasoline or petrol and the use of very high pressures (3000 to 4000 psi, or 205 to 275 bar).
CNG can be stored at lower pressure in a form known as an ANG (Adsorbed Natural Gas) tank, at 35 bar (500 psi, the pressure of gas in natural gas pipelines) in various sponge like materials, such as activated carbon[11] and metal-organic frameworks (MOFs).[12] The fuel is stored at similar or greater energy density than CNG. This means that vehicles can be refuelled from the natural gas network without extra gas compression, the fuel tanks can be slimmed down and made of lighter, less strong materials.
[edit]
Worldwide
[edit]
South Asia
A Taxicab in New Delhi. A 1998 court order requires local buses and autos in Delhi to run on Compressed Natural Gas
Pakistan currently has the highest number of vehicles running on CNG in the world followed by Argentina, Brazil and Iran. Pakistan also has the highest number of CNG stations in the world numbering more than 3600. Majority of private vehicles have converted to CNG because of cheaper price as compared to petrol. Only luxury cars and official vehicles now run on petrol. Recently, new CNG Buses had been introduced by CDGK in Karachi. Almost all car manufacturers in Pakistan (except Honda) now produce company fitted CNG kit versions. Recent hikes in CNG prices has downplayed the ambitious ventures of some of the stakeholders in this sector. It is expected that price of the CNG and Kits will come down as competition among manufacturers grows. LandiRenzo Pakistan is also exporting CNG kits to various countries including China, Brazil and Italy. Almost 2 million vehicles on the country's roads have dual fuel options with Suzuki having the highest in quantity.
CNG has grown into one of the major fuel sources used in car engines in India and Bangladesh as well. The use of CNG is mandated for the public transport system of India's capital New Delhi as well as for the city of Ahmedabad in the state of Gujarat. The Delhi Transport Corporation operates the world's largest fleet of CNG buses. Today many rickshaws as well as personal vehicles in India and Bangladesh are being converted to CNG powered technology, the cost of which is in the range of $800–$1000. In the Bangladesh capital of Dhaka not a single auto rickshaw without CNG has been permitted since 2003.[13]
In India CNG costs are at Rs. Rs 29.00 per kg (US$0.85 ) per kg compared with Rs. 59.00 (US$ 1.721) per liter of petrol (prices as of Feb. 2011 in Delhi, India). In Thailand CNG costs are at Thb 10.4 per kg (US$0.35) per kg compared with Thb 40.00 (US$ 1.35) per liter of petrol (prices as of Mar. 2011 in Bangkok, Thailand). CNG is quite notable at a cost savings of 60% along with reduced emissions and its usability by environmentally friendlier cars.
[edit]
South America
CNG station in Rosario, Argentina.
CNG vehicles are commonly used in South America, where these vehicles are mainly used as taxicabs in main cities of Argentina and Brazil.[14] 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 and Brazil are the two countries with the largest fleets of CNG vehicles,[14] with a combined total fleet of more than 3.4 million vehicles by 2009.[1] Conversion has been facilitated by a substantial price differential with liquid fuels, locally produced conversion equipment and a growing CNG-delivery infrastructure.
As of 2009 Argentina had 1,807,186 NGV's with 1,851 refueling stations across the nation,[1] or 15% of all vehicles;[14] and Brazil had 1,632,101 vehicles and 1,704 refueling stations,[1] with a higher concentration in the cities of Rio de Janeiro and São Paulo.[14][15]
Colombia had an NGV fleet of 300,000 vehicles, and 460 refueling stations as of 2009.[1] Bolivia has increased its fleet from 10,000 in 2003 to 121,908 units in 2009, with 128 refueling stations.[1] Peru had 81,024 NGVs and 94 fueling stations as 2009,[1] but that number is expected to skyrocket as Peru sits on South America's largest gas reserves.[14] In Peru several factory-built NGVs have the tanks installed under the body of the vehicle, leaving the trunk free. Among the models built with this feature are the Fiat Multipla, the newFiat Panda, the Volkswagen Touran Ecofuel, the Volkswagen Caddy Ecofuel, and the Chevy Taxi. Other countries with significant NGV fleets are Venezuela (15,000) and Chile (8,064) as of 2009.[1]
[edit]
South-East Asia
A CNG powered Volvo B10BLE bus, operated by SBS Transit in Singapore.
In Singapore CNG is increasingly being used by public transport vehicles like buses and taxis, as well as goods vehicles. However, according to Channel NewsAsia on April 18, 2008, more owners of private cars in this country are converting their petrol-driven vehicles to also run on CNG – motivated no doubt by rising petrol prices. The initial cost of converting a regular vehicle to dual fuel at the German conversion workshop of C. Melchers, for example, is around S$3,800 (US$2,500); with the promise of real cost-savings that dual-fuel vehicles bring over the long term.
Singapore currently has five operating filling stations for natural gas. SembCorp Gas Pte Ltd runs the station on Jurong Island, and jointly with Singapore Petroleum Company, the filling station at Jalan Buroh. Both these stations are in the western part of the country. Another station on the mainland is in Mandai Link to the north and is operated by SMART Energy. SMART also own a second station on Serangoon North Ave 5 which was set up end of March 2009; The fifth and largest station in the world was opened by the UNION Group in September 2009. This station is recognized by the Guniness World Records as being the laregst in the world with 46 refuelling hoses. This station is located in Toh Tuck. The Union Group, which operates 1000 CNG Toyota Wish taxis plan to introduce another 3 daughter stations and increase the CNG taxi fleet to 8000 units.
As a key incentive for using this eco-friendly fuel Singapore has a Green Vehicle Rebate (GVR) for users of CNG technology. First introduced in January 2001, the GVR grants a 40% discount on the Open Market Value (OMV) cost of newly registered green passenger vehicles. This initiative will end at the end of 2012 as the government believes the 'critical mass' of CNG vehicles would then have been built up.
The Ministry of Transport of Myanmar passed a law in 2005 which required that all public transport vehicles - buses, trucks and taxis, be converted to run on CNG. The Government permitted several private companies to handle the conversion of existing diesel and petrol cars, and also to begin importing CNG variants of buses and taxis. Accidents and rumours of accidents, partly fueled by Myanmar's position in local hydrocarbon politics,[16] has discouraged citizens from using CNG vehicles, although now almost every taxi and public bus in Yangon, Myanmar's largest city, run on CNG. CNG stations have been set up around Yangon and other cities, but electricity shortages mean that vehicles may have to queue up for hours to fill their gas containers.[17] The Burmese opposition movements are against the conversion to CNG, as they accuse the companies as being proxies of the junta, and also that the petrodollars earned by the regime would go towards the defense sector, rather than towards improving the infrastructure or welfare of the people.
In Malaysia, the use of CNG 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. 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.[18]
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.[19][20] National car maker Proton considered fitting its Waja, Saga and Persona models with CNG kits from Prins Autogassystemen by the end of 2008,[21] while a local distributor of locally assembled Hyundai cars offers new models with CNG kits.[22] 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.[19][23]
In China, companies such as Sino-Energy are active in expanding the footprint of CNG filling stations in medium-size cities across the interior of the country, where at least two natural gas pipelines are operational.[citation needed]
In India, the Delhi government,in 2004 made it mandatory for all city buses and auto rickshaws to run on CNG with the intention of reducing air pollution
[edit]
Middle East and Africa
Egypt is a top ten country in the world with more than 128,754CNG vehicles and 124 fueling stations nationwide. Egypt was also the first nation in Africa and the Middle East to open a public CNG fueling station in January 1996.[24]
In lion CNG equipped vehicles on the road. There is also a government mandate that forces local car manufacturers to produce 60% of all their new vehicles as dual fuel vehicles.
The vast majority 780000 have been produced as dual fuel vehicles by the auto manufacturer in the last two years, and the remainder have been converted utilizing after market conversion kits in workshops. There are 750 active refueling stations country wide with an additional 660 refueling stations under construction and expected to come on stream. Currently the major problem facing the industry as a whole is the building of refueling stations that is lagging behind dual fuel vehicle production, forcing many to use petrol instead.
In Turkey, Ankara has 1050 CNG buses.
[edit]
Europe
CNG powered bus in Italy
The use of methane (CNG) for vehicles in Italy started in the 1930s and has continued off and on until today. Since 2008 there have been a large market expansion for natural gas vehicles (CNG and LPG) caused by the rise of gasoline prices and by the need to reduce air pollution emissions.[25]
Before 1995 the only way to have a CNG-powered car was by having the retrofitted with an after-market kit. A large producer was Landi Renzo, Tartarini Auto, Prins Autogassystemen, OMVL, BiGAs,... and AeB for electronic parts used by the most part of kit producer.
Landi Renzo and Tartarini have divisions selling vehicles in Asia and South America.
After 1995 bi-fuel cars (gasoline/CNG) became available from several major manufacturers. Currently Fiat, Opel, Volkswagen, Citroen, Renault, Volvo and Mercedes sell various car models and small trucks that are gasoline/CNG powered. Usually CNG parts used by major car manufacturers are actually produced by automotive aftermarket kit manufacturers, e.g. Fiat use Tartarini Auto components, Volkswagen use Teleflex GFI[26] and Landi Renzo components.
In Italy, there are more than 800 CNG stations.[27] In Germany, CNG-generated vehicles are expected to increase to two million units of motor-transport by the year 2020. The cost for CNG fuel is between 1/3 and 1/2 compared to other fossil fuels in Europe.[citation needed] in 2008 there are around 800 gas(CNG) stations in Germany
In Portugal there are 4 CNG refueling stations but 3 of them do not sell to the public. Only in Braga you can find it on the local city bus station (TUB).
In Bulgaria, there are 82 CNG refuelling stations as of June 2010. One can be found in most of Bulgaria's big towns [28] - there are quite a few in Sofia, Plovdiv and Stara Zagora, as well as in the cities on the Black Sea - Varna, Burgas, Nessebar and Kavarna. CNG vehicles are becoming more and more popular in the country. The fuel is used by most taxi drivers because of its much lower price compared to petrol. It is useful to know that CNG stations in Bulgaria operate with the Italian standard nozzle typical for Eastern Europe and not with the NGV1 nozzle used in Germany, Austria, France, Belgium and other European countries.
In Republic of Macedonia, there is one CNG station located in the capital Skopje, but it is not for public use. Only twenty buses of the local Public Transport Company have been fitted to use a mixture of diesel and CNG. The first commercial CNG station in Skopje is in the advanced stage of development and is expected to start operation in July of 2011.
In Serbia, there are 4 public CNG refuelling station in the capital Beograd and near the towns of Pančevo, Kruševac and Čačak. Italian standard nozzle is used in all of them.
In Croatia, there is only one CNG station situated close to the center of Zagreb, Italian-type refuelling nozzle is used there as well.[29] At least 60 CNG buses are in use as a form of a public transport (Zagreb public transport services).
In Sweden there are currently 90 CNG filling stations available to the public (as compared to about 10 LPG filling stations), primarily located in the southern and western parts of the country as well the Mälardalen region[30] Another 70-80 CNG filling stations are under construction or in a late stage of planning (completions 2009-2010). Several of the planned filling stations are located in the northern parts of the country, which will greatly improve the infrastructure for CNG car users.[31] There are approx. 14,500 CNG vehicles in Sweden (2007), of which approx. 13,500 are passenger cars and the remainder includes buses and trucks.[32] In Stockholm, the public transportation company SL currently operates 50 CNG buses but have a capacity to operate 500.[33] The Swedish government recently prolonged its subsidies for the development of CNG filling stations, from 2009-12-31 to 2010-12-31.[34] In Spain the EMT Madrid bus service use CNG motors in 351 regular buses. Is rare to see another kind of CNG vehicle, and there's no CNG refueling stations.
As of 2010, there are 25 public CNG filling stations in the Czech republic, mainly in the big cities.[35] Local bus manufacturers SOR Libchavy and Tedom produce CNG versions of their vehicles, with roof-mounted tanks.
[edit]
North America
The Honda Civic GX is factory-built to run on CNG and it is available in several U.S. regional markets.
Buses powered with CNG are common in the United States.
[edit]
Canada
Canada is a large producer of natural gas, so it follows that CNG is used in Canada as an economical motor fuel. Canadian industry has developed CNG-fueled truck and bus engines, CNG-fueled transit buses, and light trucks and taxis. Both CNG and propane refueling stations are not difficult to find in major centres.
[edit]
United States of America
In the US, federal tax credits are available for buying a new CNG vehicle. Use of CNG varies from state to state, only 34 states have at least one CNG fueling site.[36] In California, CNG is used extensively in local city and county fleets, as well as public transportation (city/school buses), and there are 90 public fueling stations in Southern California alone. Compressed natural gas is available at 30-60% less than the cost of gasoline, as a rule of thumb, in much of California. Personal use of CNG is a small niche market currently, though with current tax incentives and a growing number of public fueling stations available, it is experiencing unprecedented growth. The state of Utah offers a subsidised statewide network of CNG filling stations at a rate of $0.85/gge,[37] while gasoline is above $4.00/gal. Elsewhere in the nation, retail prices average around $2.50/gge, with home refueling units compressing gas from residential gas lines for approx $1.50/gge. Other than aftermarket conversions, and government used vehicle auctions, the only currently produced CNG vehicle in the US is the Honda Civic GX sedan, which is made in limited numbers and available only in a few states.
An initiative, known as Pickens Plan, calls for the expansion of the use of CNG as a standard fuel for heavy vehicles has been recently started by oilman and entrepreneur T. Boone Pickens. California voters defeated Proposition 10 in the 2008 General Election by a significant (59.8% to 40.2%) margin. Proposition 10 was a $5 Billion bond measure that, among other things, would have given rebates to state residents that purchase CNG vehicles.
Congress has encouraged conversion of cars to CNG with a tax credits of up to 50% of the auto conversion cost and the CNG home filling station cost. However, while CNG is much cleaner fuel, the conversion requires a type certificate from the EPA. Meeting the requirements of a type certificate can cost up to $50,000.
[edit]
Oceania
K230UB CNG bus currently used as part of the "Scania Koala CNG Bus Trial" at ACTION in Canberra.
During the 1970s and 1980s, CNG was commonly used in New Zealand in the wake of the oil crises, but fell into decline after petrol prices receded. At the peak of natural gas use, 10 percent of New Zealand's cars were converted, around 110,000 vehicles.[38]
A Mercedes-Benz OC500LE (with Custom Coaches bodywork) running on CNG, operated by Sydney Buses in Sydney, Australia.
Brisbane Transport and Transperth in Australia have both adopted a policy of purchasing only CNG buses in future. Transperth is purchasing 451 Mercedes-Benz OC500LE buses and is undertaking trials with articulated CNG buses from Scania, MAN, and Irisbus, while Brisbane Transport has purchased 216 Scania L94UB and 240 MAN 18.310 models as well as 30 MAN NG 313 articulated CNG buses. The State Transit Authority of New South Wales (operating under the name "Sydney Buses") operates 102 Scania L113CRB buses, two Mercedes-Benz O405 buses and 300 Mercedes-Benz O405NH buses and are now taking delivery of 255 Euro 5-compliant Mercedes-Benz OC500LEs.[39]
In the 1990s Benders Busways of Geelong, Victoria trialled CNG buses for the Energy Research and Development Corporation.[40]
Martin Ferguson, Ollie Clark, and Noel Childs featured on ABC 7.30 Report raising the issue of CNG as an overlooked transport fuel option in Australia, highlighting the large volumes of LNG currently being exported from the North West Shelf in light of the cost of importing crude oil to Australia.[41]
Natural Gas Myths
1. Cars running on natural gas are only available for fleets.
Natural gas is normally used in the U.S. to generate electricity, heat houses and businesses, and as a component in a variety of industrial processes. In the United States, a very small amount of natural gas—just one-tenth of 1% of all gas consumed—is also used as a fuel for vehicles. Traditionally, CNG vehicles have been used in private and government fleets, but private citizens also own some of these vehicles.
According to the Natural Gas Vehicle Coalition, there are more than 120,000 CNG vehicles in use in the United States, and nearly 9 million worldwide.
If you're thinking of joining the league of CNG drivers in the U.S., your choice of new vehicles is limited to one: The Honda Civic GX, a natural gas-powered version of the Civic. Compared with a Civic Hybrid, you'll pay about $3,000 more for the Civic GX, although you'll be eligible for a $4,000 tax incentive. (Buyers of the Civic Hybrid receive no tax credit, because Honda has reached the cap for hybrid credits.) In addition, CNG vehicles such as the Civic GX are eligible for most of the same parking and carpool lane privileges as hybrids; in many states, CNG vehicles were using HOV lanes long before hybrids were eligible and after hybrid carpool lane stickers ran out.
Is it possible for individuals to pump CNG into their vehicle from home? Yes. FuelMaker developed Phill, the world's first home-based fueling appliance, which can be mounted to a garage wall, indoors or outdoors, to allow natural gas-powered vehicles to be refueled overnight directly from a homeowner's existing natural gas supply line.
2. CNG cars beat out hybrids on emissions.
This is only a partial myth. Natural gas, which is 90 percent methane, has a much higher octane rating than gasoline, allowing for higher compression ratios and therefore greater efficiency in the engines that use it. Natural gas burns so cleanly that CNG vehicles rival hybrids in producing extremely low levels of smog-forming pollutants. The Honda Civic GX, which burns CNG, is the perennial winner of green car awards.
However, CNG vehicles tend to have higher greenhouse gas emissions than hybrids. The CNG version of the Civic, for example, emits nearly 30 percent more greenhouse gases than the Civic Hybrid during a typical year of driving.
3. CNG cars are cheaper to run than conventional vehicles.
As petroleum prices erratically jump up and down and up again, it's tempting to look at compressed natural gas as an economic alternative. Buyer beware: the math is tricky.
Since CNG is normally sold as a gas rather than a liquid, it isn't measured in gallons, but can be converted on an energy basis that equals a gallon of gasoline. The term used for this conversation is GGE, or "gallon of gasoline equivalent."
When gasoline was about $2.25, the average price of CNG in the United States was $1.99 per GGE. While a 24 cent-per-gallon price advantage sounds attractive, CNG vehicles have lower fuel efficiency than hybrid vehicles. A Civic GX, for example, averages 32 mpg, while a Civic Hybrid is rated at 43 mpg. So while a GGE of CNG is cheaper, the Civic GX needs more fuel to operate, and therefore costs per mile are actually higher.
4. Pumping CNG into your car, and driving around with a gas-based fuel, is dangerous.
CNG is as safe, if not safer, than liquid gasoline. Although CNG is a flammable gas, it has a narrow flammability range. If released in an accident, CNG disperses rapidly, making it less likely to ignite than gasoline. CNG is also non-toxic.
The prospect of a flammable gas leaking into your garage when you are filling up, and causing an explosion or flash fire is certainly disconcerting. But according to U.S. Department of Energy studies, the annual probability of an explosion or other deflagration when the filling equipment is used properly is 1 in 7 million. An individual is 10 times more likely to be struck by lightning. Even if the system is intentionally misused, an individual is still more than twice as likely to be struck by lightning than for the Phill home refueling station to cause a deflagration.
Natural gas is normally used in the U.S. to generate electricity, heat houses and businesses, and as a component in a variety of industrial processes. In the United States, a very small amount of natural gas—just one-tenth of 1% of all gas consumed—is also used as a fuel for vehicles. Traditionally, CNG vehicles have been used in private and government fleets, but private citizens also own some of these vehicles.
According to the Natural Gas Vehicle Coalition, there are more than 120,000 CNG vehicles in use in the United States, and nearly 9 million worldwide.
If you're thinking of joining the league of CNG drivers in the U.S., your choice of new vehicles is limited to one: The Honda Civic GX, a natural gas-powered version of the Civic. Compared with a Civic Hybrid, you'll pay about $3,000 more for the Civic GX, although you'll be eligible for a $4,000 tax incentive. (Buyers of the Civic Hybrid receive no tax credit, because Honda has reached the cap for hybrid credits.) In addition, CNG vehicles such as the Civic GX are eligible for most of the same parking and carpool lane privileges as hybrids; in many states, CNG vehicles were using HOV lanes long before hybrids were eligible and after hybrid carpool lane stickers ran out.
Is it possible for individuals to pump CNG into their vehicle from home? Yes. FuelMaker developed Phill, the world's first home-based fueling appliance, which can be mounted to a garage wall, indoors or outdoors, to allow natural gas-powered vehicles to be refueled overnight directly from a homeowner's existing natural gas supply line.
2. CNG cars beat out hybrids on emissions.
This is only a partial myth. Natural gas, which is 90 percent methane, has a much higher octane rating than gasoline, allowing for higher compression ratios and therefore greater efficiency in the engines that use it. Natural gas burns so cleanly that CNG vehicles rival hybrids in producing extremely low levels of smog-forming pollutants. The Honda Civic GX, which burns CNG, is the perennial winner of green car awards.
However, CNG vehicles tend to have higher greenhouse gas emissions than hybrids. The CNG version of the Civic, for example, emits nearly 30 percent more greenhouse gases than the Civic Hybrid during a typical year of driving.
3. CNG cars are cheaper to run than conventional vehicles.
As petroleum prices erratically jump up and down and up again, it's tempting to look at compressed natural gas as an economic alternative. Buyer beware: the math is tricky.
Since CNG is normally sold as a gas rather than a liquid, it isn't measured in gallons, but can be converted on an energy basis that equals a gallon of gasoline. The term used for this conversation is GGE, or "gallon of gasoline equivalent."
When gasoline was about $2.25, the average price of CNG in the United States was $1.99 per GGE. While a 24 cent-per-gallon price advantage sounds attractive, CNG vehicles have lower fuel efficiency than hybrid vehicles. A Civic GX, for example, averages 32 mpg, while a Civic Hybrid is rated at 43 mpg. So while a GGE of CNG is cheaper, the Civic GX needs more fuel to operate, and therefore costs per mile are actually higher.
4. Pumping CNG into your car, and driving around with a gas-based fuel, is dangerous.
CNG is as safe, if not safer, than liquid gasoline. Although CNG is a flammable gas, it has a narrow flammability range. If released in an accident, CNG disperses rapidly, making it less likely to ignite than gasoline. CNG is also non-toxic.
The prospect of a flammable gas leaking into your garage when you are filling up, and causing an explosion or flash fire is certainly disconcerting. But according to U.S. Department of Energy studies, the annual probability of an explosion or other deflagration when the filling equipment is used properly is 1 in 7 million. An individual is 10 times more likely to be struck by lightning. Even if the system is intentionally misused, an individual is still more than twice as likely to be struck by lightning than for the Phill home refueling station to cause a deflagration.
Natural Gas - Overview
Natural Gas as Auto Fuel
Compared to gasoline, compressed natural gas (CNG) is cleaner, less expensive, and generally comes from domestic reserves. However, CNG vehicles also require some compromises, including the use of a special refueling infrastructure that is not widely developed in the United States.
CNG vehicles store natural gas in pressurized tanks and burn the gas in slightly modified internal combustion engines. Natural gas, which is 90 percent methane, has a much higher octane rating than gasoline, allowing for higher compression ratios and therefore greater efficiency in the engines that use it. Natural gas burns so cleanly that CNG vehicles rival hybrids in producing extremely low levels of smog-forming pollutants. The Honda Civic GX, which burns CNG, is the perennial winner of green car awards. However, CNG vehicles tend to have higher greenhouse gas emissions than hybrids. The CNG version of the Civic, for example, emits nearly 30 percent more greenhouse gases than the Civic Hybrid during a typical year of driving.
Only One Choice, For Now
Natural gas is normally used in the U.S. to generate electricity, heat houses and businesses, and as a component in a variety of industrial processes. In the United States, a very small amount of natural gas—just one-tenth of 1% of all gas consumed—is used as a fuel for vehicles. Traditionally, CNG vehicles have been used in private and government fleets, but private citizens also own some of these vehicles. According to the Natural Gas Vehicle Coalition, there are more than 120,000 CNG vehicles in use in the United States, and nearly 9 million worldwide.
If you’re thinking of joining the league of CNG drivers in the U.S., your choice of new vehicles is limited to one: The Honda Civic GX, a natural gas-powered version of the Civic. Compared with a Civic Hybrid, you’ll pay about $3,000 more for the Civic GX, although you’ll be eligible for a $4,000 tax incentive. (Buyers of the Civic Hybrid receive no tax credit, because Honda has reached the cap for hybrid credits.) In addition, CNG vehicles such as the Civic GX are eligible for most of the same parking and carpool lane privileges as hybrids; in many states, CNG vehicles were using HOV lanes long before hybrids were eligible and after hybrid carpool lane stickers ran out.
Another advantage of CNG vehicles is that, at least currently, the natural gas used to power them is primarily from domestic sources. According to the U.S. Department of Energy, just 20 percent of the natural gas consumed in the United States last year was imported, and most of those imports came from Canada—a country not considered a supporter of terrorism. Unfortunately, natural gas imports have been rising gradually since the mid-1980s, and as demand for natural gas in the U.S. grows, the amount imported from overseas may have to grow also.
Compared to gasoline, compressed natural gas (CNG) is cleaner, less expensive, and generally comes from domestic reserves. However, CNG vehicles also require some compromises, including the use of a special refueling infrastructure that is not widely developed in the United States.
CNG vehicles store natural gas in pressurized tanks and burn the gas in slightly modified internal combustion engines. Natural gas, which is 90 percent methane, has a much higher octane rating than gasoline, allowing for higher compression ratios and therefore greater efficiency in the engines that use it. Natural gas burns so cleanly that CNG vehicles rival hybrids in producing extremely low levels of smog-forming pollutants. The Honda Civic GX, which burns CNG, is the perennial winner of green car awards. However, CNG vehicles tend to have higher greenhouse gas emissions than hybrids. The CNG version of the Civic, for example, emits nearly 30 percent more greenhouse gases than the Civic Hybrid during a typical year of driving.
Only One Choice, For Now
Natural gas is normally used in the U.S. to generate electricity, heat houses and businesses, and as a component in a variety of industrial processes. In the United States, a very small amount of natural gas—just one-tenth of 1% of all gas consumed—is used as a fuel for vehicles. Traditionally, CNG vehicles have been used in private and government fleets, but private citizens also own some of these vehicles. According to the Natural Gas Vehicle Coalition, there are more than 120,000 CNG vehicles in use in the United States, and nearly 9 million worldwide.
If you’re thinking of joining the league of CNG drivers in the U.S., your choice of new vehicles is limited to one: The Honda Civic GX, a natural gas-powered version of the Civic. Compared with a Civic Hybrid, you’ll pay about $3,000 more for the Civic GX, although you’ll be eligible for a $4,000 tax incentive. (Buyers of the Civic Hybrid receive no tax credit, because Honda has reached the cap for hybrid credits.) In addition, CNG vehicles such as the Civic GX are eligible for most of the same parking and carpool lane privileges as hybrids; in many states, CNG vehicles were using HOV lanes long before hybrids were eligible and after hybrid carpool lane stickers ran out.
Another advantage of CNG vehicles is that, at least currently, the natural gas used to power them is primarily from domestic sources. According to the U.S. Department of Energy, just 20 percent of the natural gas consumed in the United States last year was imported, and most of those imports came from Canada—a country not considered a supporter of terrorism. Unfortunately, natural gas imports have been rising gradually since the mid-1980s, and as demand for natural gas in the U.S. grows, the amount imported from overseas may have to grow also.
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