Transcript WHAT IS NATURAL GAS

::NATURAL GAS VEHICLES::
SEMINAR II - MEC3892
SECTION 1
GROUP 13
DR MIRGHANI ISHAG AHMAD
MOHD REDZUAN MOHD ZAIN
0439509
MUHAMMAD AFFANDI ABD TALIB
0436397
MUHAMMAD HAFIZ AB HALIM
0432711
WHAT IS
NATURAL GAS
• a highly combustible odorless and colorless
hydrocarbon gas largely composed of
methane.
• produced in pressurized deposits located
deep in the earth's crust, commonly located
just above oil deposits.
• created in roughly the same manner as oil, by
geologic processes that act upon organic
matter over millions of years.
• High combustibility coupled with low
emissions makes natural gas a highly valued
resource.
• More economical than electricity, natural gas
is primarily used for heating homes, cooking
and running appliances such as water heaters
and clothes dryers.
HOW NATURAL
GAS PRODUCED
• Aside from natural gas deposits, tiny
microorganisms called methanogens produce
natural gas by breaking down organic matter.
• Methanogens reside in the intestines of
humans and many animals, including cattle,
and can also be found near the surface of the
earth in anaerobic conditions.
• These microorganisms are responsible for
landfill gas, more properly termed biogenic
methane, as distinguished from thermogenic
methane, or deposited natural gas.
• Though a great deal of natural gas escapes
into the air from various biogenic sources,
efforts are underway to develop technology
that can harvest unconventional natural gas.
• This would compliment natural gas deposits,
which by some estimates are quite extensive.
What is a natural
gas vehicle
• natural gas vehicles (NGVs) are designed to
run only on natural gas
• bi-fuel NGVs have two separate fueling
systems that enable the vehicle to use either
natural gas or a conventional fuel (gasoline or
diesel).
• dedicated NGVs demonstrate better
performance and have lower emissions than
bi-fuel vehicles because their engines are
optimized to run on natural gas.
• the vehicle does not have to carry two types
of fuel, thereby increasing cargo capacity and
reducing weight.
• fueled with compressed natural gas (CNG) or
liquefied natural gas (LNG).
• Compared with vehicles fueled with
conventional diesel and gasoline, NGVs can
produce significantly lower amounts of
harmful emissions.
• some natural gas vehicle owners report
service lives two to three years longer than
gasoline or diesel vehicles and extended time
between required maintenance.
• driving range of NGVs generally is less than
that of comparable gasoline and diesel fueled
vehicles because of the lower energy content
of natural gas.
• Extra storage tanks can increase range, but
the additional weight may displace payload
capacity.
• NGV horsepower, acceleration, and cruise
speed are comparable with those of an
equivalent conventionally fueled vehicle.
How Natural Gas
Vehicles Work
Light-duty natural gas vehicles
work much like gasoline-powered
vehicles with spark-ignited
engines. This schematic shows
basic CNG fuel system
components.
CNG enters the vehicle through the natural gas fill valve (A) and flows into
high-pressure cylinders (B). When the engine requires natural gas, the gas
leaves the cylinders and passes through the master manual shut-off valve
(C). The gas travels through the high-pressure fuel line (D) and enters the
engine compartment. Gas enters the regulator (E), which reduces the gas
pressure used for storage (up to 3,600 psi) to the required vehicle fuel
injection system pressure. The natural gas solenoid valve (F) allows natural
gas to pass from the regulator into the gas mixer or fuel injectors. The
solenoid valve shuts off the natural gas when the engine is not running.
Natural gas mixed with air flows down through the carburetor or fuelinjection system (G) and enters the engine combustion chambers where it is
burned to produce power, just like gasoline.
Some heavy-duty vehicles use spark-ignited
natural gas systems, but other systems exist as
well. High-pressure direct injection engines
burn natural gas in a compression-ignition
(diesel) cycle.
Advantages and
Disadvantages
Advantages
• NGVs are safer. The fuel storage tanks on an
NGV are thicker and stronger than gasoline or
diesel tanks. There has not been an NGV fueltank rupture in more than two years in the
United States.
• Natural gas costs are lower than gasoline. On
average, natural gas costs one-third less than
gasoline at the pump.
• Natural gas is convenient and abundant. A wellestablished pipeline infrastructure exists in the
United States to deliver natural gas to almost
every urban area and most suburban areas.
There are more than 1,300 NGV fueling stations
in the United States, and more are being added
every day.
• Natural gas prices have exhibited significant
stability compared to oil prices. Historically,
natural gas prices have exhibited significant
price stability compared to the prices of
petroleum-based fuels. This stability makes it
easier to plan accurately for long-term costs.
• NGVs have lower maintenance costs. Because
natural gas burns so cleanly, it results in less
wear and tear on the engine and extends the
time between tune-ups and oil changes.
Disadvantages
• they aren't as roomy as gasoline cars. This is
because NGVs have to give up precious cargo
and trunk space to accommodate the fuel
storage cylinders.
• these cylinders can be expensive to design
and build -- a contributing factor to the
higher overall costs of a natural-gas vehicle
compared to a gasoline-powered car.
• limited driving range of NGVs, which is typically
about half that of a gasoline-powered vehicle.
• For example, Honda's natural gas Civic, the Civic
GX, can go up to 220 miles without refueling. A
typical gasoline-powered Civic can go
approximately 350 miles without refueling.
• If a dedicated NGV ran out of fuel on the road, it
would have to be towed to the owner's home or
to a local natural gas refueling station, which
might be harder to find than a "regular" gas
station.
• natural gas, like gasoline, is a fossil fuel and
cannot be considered a renewable resource.
THANK YOU….