Compressed Natural Gas Essay Research Paper Compressed

Compressed Natural Gas Essay, Research Paper

Compressed Natural Gas or CNG is becoming and increasingly attractive fuel for

many transportation uses. One reason for the increase in interest in CNG is that

the emissions of a CNG vehicle are far less than that of a gas powered engine.

Other factors that make the production of CNG vehicle?s is that the gas prices

have risen in the past couple years.

Availability

Natural gas is, well, natural gas–the same stuff that heats your stove or your

house. It is largely produced domestically in the United States; it can be imported

through pipelines or as a super-cold liquid on special tanker ships, but because

this is a lot harder than pouring crude or refined oil into a tanker or a pipeline, we

haven’t built up an import dependency for natural gas as we have for petroleum.

Natural gas is distributed nationwide through an extensive network of pipelines,

which feed electrical generation plants and domestic and industrial heating uses.

In order to store a reasonable amount of fuel natural gas has to be compressed to

around 200 times atmospheric pressure–or even more for the tanks aboard large

buses! This is like the pressure a mile and a quarter under the ocean.

Advantages

It is very easy on the engine, giving longer service life and lower maintenance

costs. CNG is the least expensive alternative fuel when you compare equal

amounts of fuel energy such as gasoline. Because there is a huge and predictable

demand for natural gas from domestic, industrial, and utility users, there is a large

buffering effect against price fluctuations. At the peak of the big gasoline

price run-up in April, 1996, everyone was paying half as much for a gasoline-

gallon-equivalent of 130-octane natural gas as I would have aid for a gallon of 92-

octane unleaded gasoline! You get significantly better fuel economy on the open

road because the high octane rating of the fuel allows timing and mixture to be

adjusted for more efficiency without causing detonation (”knocking”). And

because the fuel tanks have to withstand such enormous internal pressures, they

are incredibly tough, with good results or safety. In addition, because natural gas

is lighter than air and has very narrow flammability limits, if a leak develops it is

very likely that the fuel will dissipate harmlessly into the air without causing a

danger of ignition or explosion. Natural gas has, over the course of the 1990’s,

proven to be the most effective fuel for reducing emissions in an internal

combustion engine. Other key advantages is the emissions that a CNG vechile is far

less than that of a gasoline driven car. The catalytic converter developed for the NGV

had a 1.24 L volume and was composed of palladium/platinum. The exhaust emissions

measured under durability running for petrol and CNG fuels are shown in Table below:

DistanceCONMOGNOx

CNG4 k miles0.210.0160.06

50 k miles0.440.0230.11

Petrol4 k miles0.690.0280.05

50 k miles0.790.0550.07

It can be seen that the CO and NMOG levels for the NGV are very favourable while

NOx is more for a CNG vechile.

Disadvantages

Some of the disadvantages are that the tanks are quite bulky and heavy.

Locations of the tanks is another concern from putting them in the trunk to putting

them underneath the vehicle. Some other problems that affect use of widespread CNG

is the lack of refueling stations available to refuel and CNG vechile. High capital costs

are involved in setting up a network of refuelling stations. This presents problems that

must be resolved in the early stages of a national development programme. The build-

up of custom at a new public station may be slow, with correspondingly long times for a

return on capital. Another dissadvantage is that cost to convert the vechile. The first

cost of a conversion will be in the range $1,000 to $3,500 and the payback from two

to seven years, depending on annual mileage. Any future reductions in the cost of

lightweight cylinders will have an important effect on the conversion cost.

http://www.greentie.org/class/ixe03. htm

http://www.drvenergy.com/

http://www.energy.ca.gov/afvs/ngv/index.html

http://www.eintoday.com/

http://www.pressedsteel.com/

http://www.clair.org/CNG.htm

http://www.cganet.com/