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| Q. |
What is a natural gas vehicle? |
| A. |
A natural gas vehicle (NGV) is a car, truck, van or bus which uses compressed natural gas to fuel its engine. Because it is not a liquid fuel, natural gas is compressed at 3,000 or 3,600 pounds per square inch so that it can be stored in steel, aluminum, fiberglass or carbon-fiber cylinders.
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| Q. |
How do NGVs work? |
| A. |
NGVs work like conventional liquid gasoline or diesel-powered vehicles in that they burn a gaseous mixture of fuel and air in an engine; however, natural gas has the distinct advantage of already being a gas, which helps the engine run cleaner.
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| Q. |
How are NGVs refueled? |
| A. |
At fueling locations, natural gas is compressed and dispensed into vehicles in much the same way as gasoline. Fleet fueling stations can be conveniently located on-site, using either the "quick-fill" or "time-fill" method of fueling. Quick-fill refueling takes about three to seven minutes. Time-fill refueling is usually done overnight, in about five to eight hours. A refueling station may be installed wherever natural gas is available. NGVs are convenient for fleets since the vehicles usually return to the same location each night for refueling.
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| Q. |
Is compressed natural gas safe? |
| A. |
Yes. The cylinders that hold the compressed natural gas are significantly stronger than gasoline tanks. They have withstood impact and bonfire testing and meet or exceed U. S. Department of Transportation safety standards. Even in the unlikely event of a leak, CNG will not form combustible pools on the ground, as other fuels do. Because it is lighter than air, it will rise and dissipate if released. Furthermore, natural gas is not toxic to touch.
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| Q. |
How do NGVs comply with clean air regulations? |
| A. |
NGVs are simply the cleanest of any vehicles in commercial production today. In fact, NGVs produce only 5% to 10% of the emissions allowable even by today's most stringent standards. Clearly, NGVs present the cleanest choice for today and tomorrow.
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| Q. |
What are the properties of NGV? |
| A. |
Natural gas has been used as a vehicular fuel for more than 80 years. NGV was first introduced in Italy where more than 300,000 cars are now driven by natural gas.Many other countries, spanning from Americas to Asia and Australia, have adopted NGV as one of the fuels for cars. Today, more than one million cars around the globe are powered by NGV.
Comparative Safety Features of Fuels
| Comparisons |
NGV |
LPG |
Gasoline |
Diesel |
| Physical Status |
Gas |
Gas/Liquid
at
7 bar |
Liquid |
Liquid |
| Weight |
Lighter than
air
(dispersed when leaked) |
Heavier than
air
(tend not to scatter) |
Heavier
than
air |
Heavier
than
air |
Flammability limit
(% by volume) |
5 - 15% |
2.0 - 9.5% |
1.4 - 7.6% |
0.6 - 7.5% |
| Auto Ignition Temperature |
650 °C |
481 °C |
275 °C |
250 °C |
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| Q. |
What are the types of NGV engines? |
| A. |
| 1. |
| Dedicated NGV or the dedicated natural gas vehicle which operates using only natural gas. |
A vehicle that operates only on natural gas and is therefore optimized to take full advantage of the high octane inherent in natural gas, thus using the fuel more efficiently. A dedicated vehicle only operates on one fuel.
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| 2. |
| Dedicated NGV or the dedicated natural gas vehicle which operates using
two separate fuel systems. |
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Bi-fuel , a vehicle with two separate fuel systems designed to run on either an alternative fuel or a conventional fuel using only one fuel at a time. Typically, gasoline/natural gas bi-fuel vehicles are gasoline vehicles converted to bi-fuel operation by adding natural gas fuel storage, pressure regulation and control systems.
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Diesel Dual Fuel,- a vehicle designed to operate on some combination of both an alternative fuel and conventional fuel at the same time. Dual-fuel vehicles have two separate fuel systems, though a duel-duel vehicle can operate on one fuel or the other.
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| Q. |
What is the worldwide usage of NGV? |
| A. |
Natural gas has been used as a vehicular fuel for more than 80 years. NGV was first introduced in Italy where more than 300,000 cars are now driven by natural gas. Many other countries, spanning from Americas to Asia and Australia, have adopted NGV as one of the fuels for cars. Today, more than one million cars around the globe are powered by NGV.
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| Q. |
NGV in Thailand |
| A. |
1984: NGV made its debut in Thailand in 1984 when a number of Bangkok buses and tuk-tuk taxis underwent the NGV experimental program. Technically speaking, the experiment was a success with satisfactory engine performance being noted. However, the lower cost of motor fuels and the high costs of modifying engines to NGV fuelling at that time made the program not economical.
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1993: In 1993, the Anand Panyarachun Administration's policy in addressing the air pollution problems revived the interest in NGV. Funding supports were granted to the Bangkok Mass Transit Authority (BMTA) to acquire 82 NGV buses and the country's first NGV filling station being built by PTT at BMTA's Rangsit depot in Bangkok's northern outskirts.
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1999: In 1999, PTT embarked on another trial, modifying 12 petrol engine cars and 16 diesel engine vehicles into oil/gas bi-fuelling. Again, the results were satisfactory.
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2000: A larger NGV test program was launched a year later when PTT sponsored the costs of turning 100 city taxis into oil/NGV burning vehicles.
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The success led PTT to start a pilot project by PTT bearing the cost of changing 1,000 taxies into NGV powered cars. In parallel, PTT has started building NGV filling stations in Bangkok and adjoining areas.
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| Q. |
NGV Stations in Thailand |
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| There are three types of NGV stations: |
| 1. |
Conventional stations are located along gas pipelines and are capable of only filling gas to cars.
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| 2. |
Mother stations are built along gas pipelines and fill gas to cars and gas tankers.
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| 3. |
Daughter stations receive gas from tankers which transports gas from Conventional stations for filling on cars.
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| The NGV filling stations operational are: |
| 1. |
Rangsit NGV Filling Station at BMTA Garage |
| 2. |
PTT service station operated by Sricharoen Phan Partnership on Vibhavadi-Rangsit Road |
| 3. |
PTT service station run by Kim Jin Ci near Anusorn Sathan Intersection |
| 4. |
PTT service station managed by the State Railways of Thailand Cooperative near Mor Chit II Terminus |
| 5. |
PTT service station near Three head-Elephant musuem, Samutprakarn province |
| 6. |
PTT service station on Krungthep-Nontaburi Road |
| 7. |
PTT service station on Pattanakarn Road |
| 8. |
PTT service station on Rama III Road |
| 9. |
PTT Service station on Bangna-Trad k.m. 55 near Amatanakorn Industrial Estate, Chonburi Province |
| 10. |
PTT Service station on Sukhumvit Road, Entrance of Maptaphut Industrial Estate, Rayong Province
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| Q. |
What are the types of Cylinders used? |
| A. |
Type 1: This is an all metal - cylinder made of steel. There is no covering, other than paint, on the outside of the cylinder. This is the most common type of cylinder.
Type 2: This is a metal cylinder (steel or aluminum) with a partial wrapping that goes around the cylinder. The wrapping is usually made of glass, aramid or carbon, contained in an epoxy or polyester resin.
Type 3: This type of cylinder is fully wrapped with the same kind of material used for the partial wrapping of a Type 2 cylinder. This type of cylinder has a metal liner usually aluminum.
Type 4: This type of cylinder is fully wrapped with the same kind of material used for the partial wrapping of a Type 2 cylinder. This type of cylinder has a plastic liner.
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