What Is LNG?
LNG (liquefied natural
gas) is an economical alternative to firm
pipeline capacity. The use of LNG is very common
in the Northeast area of the United States. The
process is not new. The liquefaction of natural
gas dates back to the early 1900's. LNG has been
used as a vehicle fuel since the mid 1960s.
LNG is produced in a
liquefaction plant where natural gas is
liquefied, stored in an insulated storage tank,
and, when needed, is pumped out of the tank as a
liquid, heated in a vaporizer or re-gasifier and
delivered to the pipeline or distribution system
at a compatible temperature and pressure. The
technology came out of NASA's space program.
When natural gas is
cooled to a temperature of approximately -260
degrees F at atmospheric pressure, it condenses
to a liquid called Liquefied Natural Gas (LNG).
One cubic foot of liquid is equal to 618 cubic
feet of natural gas found at a stove-top burner.
LNG weighs about 55 percent less than water. LNG
is odorless, colorless, non-corrosive, and
non-toxic. When vaporized, it burns only in
concentrations of 5 percent to 15 percent when
mixed with air. Neither LNG, nor its vapor can
explode in an unconfined environment.
How Is LNG
Transported?
In the United States,
the Department of Transportation (DOT) regulates
the transportation of LNG as well as the drivers
of the trucks. The double-walled trucks are like
"thermos-bottles" on wheels. They
transport LNG at -250 degrees. LNG can be stored
up to three days in the tanks of the trucks
without losing any LNG through the boil-off
process.
The inner tanks of the
trucks are made of thick aluminum designed to
withstand up to 100 pounds of pressure. There is
a steel outer shell around the outside of the
inner tank. The tanks are designed to withstand
most accidents that may occur during the
transportation of LNG.
The pressurized tank
does not use pump; it uses a series of relief
valves to release pressure. Additionally, tank
pressure is used to transfer the LNG from the
tank to the storage facility.
Is LNG Safe?
During the years of
controlled testing by independent laboratories
and hundreds of thousands of gallons
(intentional) spilled LNG, ignition of a vapor
cloud has yet to cause an explosion. In fact,
some testing involved initiating the combustion
of the gas cloud with high explosives. The
strength of the detonation was no stronger than
that delivered by the explosives. Conclusion: The
ignition of LNG or LNG vapor will not cause an
explosion in an unconfined environment.
Natural gas is only
combustible at a concentration of 5 to 15 percent
when mixed with air. And, its flame speed is very
slow. These facts may best be experienced by a
simple demonstration often done at LNG fire
schools. A large pit, i.e., 20' x 20', is filled
with LNG, allowing the vapor cloud to drift with
the wind. The cloud is ignited with a torch from
a downwind side. Ignition typically occurs near
the visible fringes of the cloud. The resulting
flame front moves back toward the pit at a speed
only slightly faster than a walk.
How Many LNG Storage
Facilities Are There In The U.S.?
Currently, there are 39
satellite and 55 liquefaction facilities in the
United States. In other countries, there are 81
satellite and 14 liquefaction facilities. Since
deregulation of the natural gas industry, the
construction of LNG facilities in the United
States has increased. The role of LNG facilities
is changing from peak shaving natural gas demand
to base loading or supplying of natural gas year
round.
Why Should Our Company
Consider LNG?
The economics
of a peakshaving plant are typically based upon
avoided pipeline demand charges along with a
component of avoided capital cost for some
alternative pipeline solution. Pipeline capacity
is commonly purchased for $1,000,000-$4,000,000
per year for each 10,000 dekatherms/day of
capacity. Small LNG peakshaving facilities can
typically be constructed for a one time capital
cost of $1,000,000-$4,000,000. The annual
carrying costs for these facilities are derived
from ($Financing + $O & M). If a $2,000,000
plant has an annual carrying cost of $300,000 per
year, and it can avoid $1,000,000 per year in
demand charges from the pipeline, then it is easy
to understand the economic justification of
peakshaving.
The economics
of a base-load facility are somewhat
different. The economics of base-load facilities
are generally driven by cost of the base-load LNG
vapor as compared to alternative fuels available.
The facilities can be installed at industrial
sites or a stand alone utility system. Many
operators are unaware of the great potential at
the industrial sites for volumes of sales. An
industrial customer running three shifts at 100
dekatherms per hour can use 800,000 dekatherms
per year of load. LNG can be produced for prices
of $3.00-$4.00 per dekatherm. Transport can
commonly cost between $.50-$2.00 depending on
travel time. The simplified cost per dekatherm of
vaporized LNG is now determined by ($Fuel Cost +
$Annual Financing + $Annual O & M + $ Annual
Profit) annual load.
Who Do I Contact For
More Information?
For more
information, please contact us at: info@northstarind.com. Northstar Industries leads the
way in turn-key satellite LNG facility
pre-engineering, permitting, and construction
utilizing its modular system design. For
an online LNG site tour, click here.
