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Chart Industries LNG Technology Brings Clean Energy To End Users
Introduction
No Pipeline? No Problem
Medium Size LNG Technology Value Chain
Liquefaction Technology
Liquefier Storage Systems
Transport of LNG
Satellite Stations
Re-Fueling Stations
Vehicle Onboard LNG Systems
LNG Satellite Station. Turn-Key delivered to Naturgass
Vest, Norway, with storage capacity of 1 500 000 liters and delivery
of 4 200 Nm3/hour, serving an aluminum foundry. NGV is a LNG whole-saler.
The gas is delivered by NGV’s ship which can be seen in the
background. The ownership to this installation, located at Sunndalsøra,
has since been transferred to Naturgass Møre AS.
Introduction
Natural gas is becoming one of the most important primary energy
sources for the 21st century. This is due to the large reserves
throughout the world and because it is a relatively clean fuel.
Natural gas produces about half of the carbon dioxide compared to
other fossil fuels, with very few undesirable emis-sions. Natural
gas is the clean fuel of choice as it helps solve two major environmental
concerns: air pollution and the greenhouse effect.
An important issue of natural gas technology is that gas resources are located in isolated parts of the world, often far from concentrated energy consumption. In order to transport the gas, long distance pipelines or other means of transport, such as large ocean tankers, are required.
Large natural gas liquefiers and LNG tankers have been in service for decades. There is widespread consensus among industry experts that the global Liquefied Natural Gas (LNG) trade is primed to develop exponentially over the next ten years. Worldwide production of LNG is expected to double within next six years. However, at the present time, most of the LNG is being converted to gas and compressed into long distance pipelines.
No
Pipeline? No Problem
A new trend in the industry is utilizing a medium size LNG system,
also called the “virtual pipeline”, which delivers LNG
directly to customer sites. These systems are independent of pipe-lines
and therefore, offer improved access to the benefits of natural
gas, reaching a larger number of companies, applications and end
users. European nations with rich resources of natural gas, such
as Norway or Poland, or coun-tries importing large quantities of
LNG, such as Spain, Turkey or Portugal, have instituted strategies
to encourage the formation of infrastructure needed for distribution.
Traditional underground pipelines are too expensive for gasifica-tion
of low populated regions or areas with rich existing underground
infrastructure. Also, the required lead-time of building such pipelines
is several years, which is not sufficient for the growing demand
resulting from substitution of oil in certain regions. Liquefaction
of natural gas and distributing as liquid to various points of use
is a viable solution. The LNG Value Chain is an expression of the
turnkey processes, which enable the end use of LNG.
Medium Size LNG Technology Value Chain
•
Source of LNG for distribution is the most important
component. A portion of LNG can be sold from on-shore re-ceiving
terminals, while the major portions are converted to gas and transported
via pipelines. However, in some cases there are reasons, to build
local liquefiers.
• Liquefier storage tanks ensure reten-tion
capacity for distribution.
• Transport vessels and vehicles serve delivery
logistics systems.
• Satellite stations built at the gas user
site or at local distribution centers.
• Vaporization systems are the majority portion
of the satellite station. They convert liquefied gas back into the
gase-ous phase to serve process technologies and heating systems.
• Vehicle refueling stations are a special
kind of satellite station which provides refueling of vehicles operating
on compressed natural gas (CNG) or on liquefied natural gas (LNG)
directly onboard.
• Vehicle onboard LNG systems ensure storage
and vaporization of LNG for delivery of pressurized gas to the vehicle
engine.
Chart-Industries
Inc. provides products and services which span the entire
LNG Technology Chain. Photo: Storage tank containing 257.000 liters of LNG with a pump system for filling road trailers, located at a Gasnor LNG liquefac-tion plant in Snurrevarden, Norway. |
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Liquefaction
Technology
The process of liquefaction is based on cooling the gas to its condensation
temperature –162°C, which is in the range of “cryogenic”
temperatures and requires very special, highly technical designs.
By transferring gas to a liquid state, this process reduces its
volume nearly 600 times for simplified storage and transportation.
Large quantities of LNG are available at continent shore receiving terminals with capacities of tens of millions of liters and distribution systems are in operation from several technicians. It is relatively easy and low cost to transport LNG over the road for distances of 500 km, e.g.
In
some cases, local liquefaction has been preferred, especially:
• If local wells of gas, distant from industry and cities
become commercialized.
• If the gas wells contain a larger concentration of nitrogen,
which is inert, reduces the energy value of the gas and can only
be rejected by gas liquefaction.
• If smaller settlements in low populated areas should be
gasified and building pipelines is not economical, gas can be liquefied
at transit pipelines for off-pipeline distribution.
• If pressure reduction stations between high pressure and
low pressure pipelines systems offer an opportunity to liquefy gas
without energy consumption.
• If the gas can be liquefied, without energy consumption,
at nitrogen vaporization stations.
Liquefier
Storage Systems
These components consist of one or more tanks. Because of LNG’s
low temperature, they are built as double shell vessels with highly
effective powder-vacuum or multi-layer-vacuum insulation, which
ensures long time storage with limited vaporization. Their volume
is determined typically for one to two weeks’ liquefier
capacity.
Satellite
Stations
These stations are built at the gas end user or as source for
local pipeline network from the storage tank. Storage Tanks are
sized for a reasonable retention time of three to fourteen days,
depending on consumption capacity.
Operation of satellite vaporizing stations range from manual, to fully automated, with no personnel and with possibility to be monitored and controlled by telemetry systems from commercial offices located hundreds of kilometers away. On-site automation systems ensure proper gas pressure in the downstream pipelines without external energy consumption. This is accomplished by using the heat of ambient air or burning 2% of the gas flow rate in gas-heated vaporizers.
Emergency shut down systems ensure total safety of these plants should there be any unexpected external fire or gas leak. The use of stainless steel as a main construction material along with state of the art manufacturing and construction technology, and rigorous inspection of design and products by state authorities provide the best guarantee of the plants reliability and safe operation. A distinct advantage of LNG satellite stations is the flexibility of the flow control rate in the range of 0 to 100% with potential for several hours overload.
Municipal LNG gasification satellite station technology,
storage capacity 60 000 li-ters, delivered to KRI, Poland
There are several kinds of satellite station applications:
• Direct heating and process technology systems ensure continuous gas delivery according to consumption rates with possible seasonal or daily diagram variations. High reliability and several years’ uninterrupted operation are typical requirements. Small plants GreenBox, with a capacity of 21000 liters, can be delivered in containers for easy to install, easy to move designs.
• Back-up systems are incorporated at sensitive process technologies like glass factories, which normally oper-ate on pipelines, but a back up system is needed for any potential pipeline interruption. Storage capacity is sized for coverage of limited time operation needed for failure rectification or for safe shutdown of the plant without damage to equipment or product.
• Peak shaving systems are designed to compensate for deficiencies in gas delivery, when gas delivery by pipeline cannot cover consumption due to limited gas supply, often related to source capacity or pipeline sizing. Typically they are used for additional heating during several very cold winter days.
LNG semi-trailer with a capacity of 56 000 liters
from a series, delivered to Naturgass Vest, Norway.
Re-Fueling
Stations
LNG stations serve vehicle fleets, operating directly on LNG onboard.
Heavy-duty trucks, busses, refuse vehicles and frequently operated
fleet vehicles such as taxis are typical vehicles with great potential
for LNG fueling. Compared to much more traditional CNG systems,
LNG enables lower vehicle dead weight and longer runs because
of its high density and low pressure. Centrifugal pumps ensure
delivery of LNG into vehicles with the same speed, as high performance
petrol pumps.
LCNG stations can use LNG to support the operation of existing CNG vehicles. High-pressure piston pumps deliver LNG into atmospheric vaporizers and buffers so that CNG vehicles can be refueled quickly.
LNG/LCNG
stations are mostly combined for fueling both versions of vehicles.
Design of the vehicle refueling station starts from vessel integrated
systems, for the smallest pilot plants for several vehicles, over
containerized Gas Box or Black Box. Easy to install, easy to move
variants, up to large stations with several storage tanks and
multiple CNG and LNG dispensers for large fleets and public refueling.
The above mentioned vessel truck, Orca, can be used as a mobile
re-fueling station.
Underground tanks are a typical option for urban areas to conserve real estate requirements and to meet architectural regulations.
Both the LNG and LCNG Chart stations are well customized for easy and self-service operation and card-pay systems.
World’s largest LNG/LCNG station built by
Chart-NexGen in California. 4×60.000 liters storage capacity,
6 LNG dispensers and 3 LCNG dispensers. Serving 200 refuse vehicles.
Vehicle
Onboard LNG Systems
These systems consist of one or more fuel tanks, super-insulated,
which ensures long time on board storage and loss-free operation.
LNG is being vaporized during engine operation in a vaporizer
heated by the engines cooling system. A pressure regulator controls
delivery of gas to the vehicle’s engine and maintains a
constant pressure. 5000 LNG vehicles with Chart systems operate
in USA and 250 in Europe (UK, Spain). LNG technology, thanks to
its effectiveness, stimulates further progress of natural gas
vehicles (NGV’s), for cleaner cities and lower-cost fueling.
LNG Applications for Vehicle Fueling solves the existing deficiency of the CNG vehicle system – binding refueling stations to pipelines. LNG and LCNG stations make it possible to build a continuous network of re-fueling stations in regular distances, at accessible places directly on motorways. This would stimulate wide use of natural gas for the transport sector and it would help to achieve the European Union target to substitute 10% of vehicle consumption by natural gas till the year 2020. This represents additional 47.000.000.000 m³ of gas per year.
