Compressed Natural Gas
www.CompressedNaturalGas.net
We provide Compressed
Natural Gas, Liquefied Natural Gas and Biomethane investment capital and engineering services
for CNG project development.
Our
company also provides Demand Side Management,
Energy Efficiency Measures,
and Energy Conservation
Measures design and project
development solutions that may provide a return on investment in less than
12 months. We also offer energy-saving technologies that may
include; Absorption Chillers, Adsorption
Chillers, Automated Demand
Response, Cogeneration, Demand
Response Programs, Demand Side
Management, Energy Master
Planning, Engine Driven Chillers,
Trigeneration and Energy
Conservation Measures.
Our company provides turn-key project solutions that include all or part of the following:
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Engineering and Economic Feasibility Studies
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Project Design, Engineering & Permitting
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Project Construction
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Project Capital
and Investment Funding
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Financing Options
(including long-term capital leasing and attractive programs for
municipal/governmental entities.
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Shared/Guaranteed Savings program with no capital
requirements (qualified clients)
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Project Commissioning
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Operations & Maintenance
For more information: call us at:
832-758-0027
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Compressed natural gas is widely available throughout
the U.S. from domestically produced natural gas wells and
natural gas pipelines and local distribution companies.
Natural gas is available to end-users through the utility
infrastructure. It is also clean burning and produces
significantly fewer harmful emissions than reformulated
gasoline or diesel when used in natural gas vehicles.
In addition, commercially available medium- and heavy-duty
natural gas engines have demonstrated over 90% reductions of
carbon monoxide (CO) and particulate matter and more than
50% reduction in nitrogen oxides (NOx) relative
to commercial diesel engines. Natural gas can either be
stored onboard a vehicle as compressed natural gas (CNG) at
3,000 or 3,600 psi or as liquefied natural gas (LNG) at
typically 20-150 psi. Natural gas can also be blended with
hydrogen.
Compressed Natural Gas
and
Compressed Natural Gas Vehicles
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What Types of Vehicles Run
on Compressed Natural Gas?
According to the Natural Gas
Vehicle Coalition (NGVC), as of 2005 there are
130,000 light- and heavy-duty compressed
natural gas (CNG) and liquefied natural gas
(LNG) vehicles in the United States and 5
million worldwide.
Dedicated 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).
In general, dedicated NGVs demonstrate better
performance and have lower emissions than
bi-fuel vehicles because their engines are
optimized to run on natural gas. In addition,
the vehicle does not have to carry two types
of fuel, thereby increasing cargo capacity and
reducing weight.
There are a few light-duty NGVs still
available, but if you want a specific type of
vehicle, you may want to consider retrofitting
a vehicle to an NGV by using an aftermarket
conversion system. Heavy-duty NGVs are also
available as trucks, buses, and shuttles.
Approximately one of every five new transit
buses in the United States is powered by
natural gas.
As a new twist, tests are being conducted
using natural gas vehicles that are fueled
with a blend of compressed natural gas and
hydrogen.
Vehicle Availability
This model year, auto
manufacturers are producing fewer models than
in years past. In order to get more vehicle
options, you may choose to retrofit your own
vehicle.
Fuel Availability
CNG fueling stations are
located in most major cities and in many rural
areas. Public LNG stations are limited and
used mostly by fleets and heavy-duty trucks.
LNG is available through suppliers of
cryogenic liquids.
Vehicle Safety
Natural gas vehicles are just
as safe as today's conventional gasoline and
diesel vehicles. They use pressurized tanks,
which have been designed to withstand severe
impact, high external temperatures, and
environmental exposure.
Adequate training is required to operate
and maintain natural gas vehicles because they
are different than gasoline or diesel
vehicles. Training and certification of
service technicians is required.
Vehicle Costs
In general, a natural gas
vehicle can be less expensive to operate than
a comparable conventionally fueled vehicle
depending on natural gas prices. Natural gas
can cost less than gasoline and diesel (per
energy equivalent gallon); however, local
utility rates can vary.
Purchase prices for natural gas vehicles
are somewhat higher than for similar
conventional vehicles. The auto manufacturers'
typical price premium for a light-duty CNG
vehicle can be $1,500 to $6,000, and for
heavy-duty trucks and buses it is in the range
of $30,000 to $50,000. Federal and other
incentives can help defray some of the
increase in vehicle acquisition costs. In
addition, fleets may need to purchase service
and diagnostic equipment if access to
commercial CNG/LNG vehicle maintenance
facilities is not available.
Retrofitting a conventional vehicle so it
can run on CNG may cost $2,000 to $4,000 per
vehicle.
Maintenance Considerations
High-pressure tanks that hold
CNG require periodic inspection and
certification by a licensed inspector.
Fleets doing on-site maintenance may need
to upgrade their facilities to accomodate NGVs.
Costs for upgrading maintenance facilities
will depend on the number of modifications
required.
Some natural gas vehicle manufacturers now
recommend oil changes at intervals twice as
long as similar gasoline or diesel models
(10,000-12,000 miles). Refer to the vehicle
owner's manual or consult the manufacturer to
determine proper maintenance intervals.
Benefits
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Compared with vehicles fueled by
conventional diesel and gasoline, NGVs can
produce significantly lower amounts of
harmful emissions such as nitrogen oxides,
particulate matter, and toxic and
carcinogenic pollutants. NGVs can also
reduce emissions of carbon dioxide, the
primary greenhouse gas. For details, see
the following publications from the U.S.
Environmental Protection Agency:
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The cost of a gasoline-gallon equivalent
of CNG can be favorable compared to that
of gasoline, but varies depending on local
natural gas prices.
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Natural gas is mostly domestically
produced. In 2004, net imports of natural
gas was approximately 15% of the total
used, with almost all the imports coming
from Canada.
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Some natural gas vehicle owners report
service lives 2 to 3 years longer than
gasoline or diesel vehicles and extended
time between required maintenance.
Performance
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Vehicle range for CNG and LNG vehicles
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 some payload capacity.
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NGV horsepower, acceleration, and cruise
speed are comparable with those of an
equivalent conventionally fueled vehicle.
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Depending on the number of cylinders and
their locations, some payload capacity may
be compromised with NGVs.
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Bi-fuel NGVs offer a driving range
similar to that of gasoline vehicles.
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Compressed Air
Energy Storage
www.CompressedAirEnergyStorage.com
Compressed
Air Energy Storage ("CAES") provides a number of economic and environmental
benefits over traditional power generation technologies. Unlike most companies,
we are equipment supplier/vendor neutral. This means we help our clients select the best equipment for their specific application. This approach provides our customers with superior performance, decreased operating expenses and increased return on investment.
What is
Compressed Air Energy Storage?
On nights and weekends, Compressed Air Energy Storage ("CAES")
systems compresses air on the surface and then pumps the air underground
to a cavern or former mine. There, it is stored as an energy source. During the day and at peak times, air is released and heated using a small amount of natural gas. The heated air flows through a turbine generator to produce electricity. In conventional gas-turbine power generation, the air that drives the turbine is compressed and heated using natural gas. On the other hand, compressed air energy storage technology needs less gas to produce power during periods of peak demand because it uses air that has already been compressed and stored underground.
Two major compressed air energy storage plants exist worldwide: a CAES
plant in Alabama, which is 11-years-old and rated at 110 megawatts, and a German facility that is 23-years-old and 290 MW.
A new CAES plant is under development located near Cleveland and will be capable of generating 2,700 MW.
Currently, manufacturers can create CAES machinery for facilities ranging from 5 to 350 MW.
Palo Alto, Calif.-based EPRI has estimated that more than 85 percent of the U.S. has geological characteristics will accommodate underground compressed air energy storage.
Studies have concluded that the technology is competitive with combustion turbines and combined-cycle units, even without attributing some of the uncommon benefits of energy storage.
Compressed air energy storage utilities can use off-peak electricity to compress air and store it in airtight underground caverns.
When the air is released from the underground mine or cavern, the air expands through a combustion turbine to create electricity. Nearly two-thirds of the natural gas in a conventional power plant is consumed by a typical natural gas turbine because the gas is used to drive the machine's compressor.
By comparison, a compressed-air storage plant uses low-cost heated compressed air to power the turbines and create off-peak electricity, conserving some natural gas.
Compressed air energy storage has a few disadvantages. The disadvantage is that energy is lost when it is “pumped” into the cavern and then re-extracted as compressed air.
Some estimates say that it could be as high as 80 percent. That, in effect, means that the selling price must accommodate that shortcoming, which may drive up rates for consumers.
Also, building underground storage can be expensive, which might make some prospective projects infeasible.
But, with gas prices estimated to be in the $5-6 per million BTU range in
the short to medium term, an investment in underground storage could pay for itself over time.
Moreover, if the nation develops an energy policy that pushes renewable power sources, the idea may catch on.
If that happens and a debate over the technology ensues, developers say that they can win approval from stakeholders.
Because storage is used with renewable forms of power, capital costs can be more readily recouped.
And furthermore, wind and solar energy, for example, can be stored whenever it is generated and then released on demand—helping to negate the argument that those power sources are intermittent and therefore unreliable.
It's a cost effective solution, developers add, because it would replace expensive “peaking” units that provide power during the hottest summer days or the coldest winter nights.
Air is stored in the form of compressed air energy during off peak hours and then released during the periods of highest demand, which will also lower the prices that consumers pay for power.
At the same time, compressed air energy storage units can reduce the stress on base load plants that would otherwise have to ramp up and down.
The Iowa Association of Municipal Utilities, for example, is considering a 300-megawatt plant that is comprised of a 100 MW wind farm and a 200-MW compressed air energy storage facility.
The association has spent $1.5 million studying the concept, which will likely come to fruition and be announced in mid year, it says. The plant would store energy in the form of compressed air and it would be withdrawn when it is needed.
“In the long run, this is cheaper than building a coal or natural gas plant,” says Bob Haug,
Executive Director of the Iowa Association of Municipal Utilities, because the possible facility would use two-thirds less natural gas than it would otherwise as well as the fact that the incremental cost to produce wind energy is negligible. By extension, compressed air energy storage plants would minimize the release of harmful emissions created by fossil fuel-fired generators.
Compressed air energy storage is unfamiliar to many. But the concept has been around for 20 years, albeit its usage is limited.
Still, the compression, storage and electric generation apparatus is made up of the same equipment that is used in gas storage and power plants.
With the emergence of other possible CAES facilities, and the impending decision by the Iowa Association of Municipal Utilities, the idea is sure to get a much closer examination.
"I think that it is important for all states to look at their alternative energy generation resources and ways of storing energy," says John Turner, a researcher at National Renewable Energy Laboratory.
"Compressed air energy storage is definitely one."
Waste
Heat Recovery
Many industrial processes
generate large amounts of waste energy that simply pass out of plant
stacks and into the atmosphere or are otherwise lost. Most industrial
waste heat streams are liquid, gaseous, or a combination of the two and
have temperatures from slightly above ambient to over 2000 degrees F.
Stack exhaust losses are inherent in all fuel-fired processes and increase
with the exhaust temperature and the amount of excess air the exhaust
contains. At stack gas temperatures greater than 1000 degrees F, the heat
going up the stack is likely to be the single biggest loss in the process.
Above 1800 degrees F, stack losses will consume at least half of the total
fuel input to the process. Yet, the energy that is recovered from waste
heat streams could displace part or all of the energy input needs for a
unit operation within a plant. Therefore, waste heat recovery offers a
great opportunity to productively use this energy, reducing overall plant
energy consumption and greenhouse gas emissions.
Waste heat recovery methods used with industrial process heating
operations intercept the waste gases before they leave the process,
extract some of the heat they contain, and recycle that heat back to the
process.
Common methods of
recovering heat include direct heat recovery to the process, recuperators/regenerators,
and waste heat boilers. Unfortunately, the economic benefits of waste heat
recovery do not justify the cost of these systems in every application.
For example, heat recovery from lower temperature waste streams (e.g., hot
water or low-temperature flue gas) is thermodynamically limited. Equipment
fouling, occurring during the handling of “dirty” waste streams, is
another barrier to more widespread use of heat recovery systems.
Innovative, affordable waste heat recovery methods that are
ultra-efficient, are applicable to low-temperature streams, or are
suitable for use with corrosive or “dirty” wastes could expand the
number of viable applications of waste heat recovery, as well as improve
the performance of existing applications.
Various Methods for Recovery of Waste Heat
Low-Temperature
Waste Heat Recovery Methods – A large amount of energy in the form of
medium- to low-temperature gases or low-temperature liquids (less than
about 250 degrees F) is released from process heating equipment, and much
of this energy is wasted.
Conversion of Low Temperature Exhaust Waste Heat – making efficient use
of the low temperature waste heat generated by prime movers such as
micro-turbines, IC engines, fuel cells and other electricity producing
technologies. The energy content of the waste heat must be high enough to
be able to operate equipment found in cogeneration and trigeneration power
and energy systems such as absorption chillers, refrigeration
applications, heat amplifiers, dehumidifiers, heat pumps for hot water,
turbine inlet air cooling and other similar devices.
Conversion of Low Temperature Waste Heat into Power –The steam-Rankine
cycle is the principle method used for producing electric power from high
temperature fluid streams. For the conversion of low temperature heat into
power, the steam-Rankine cycle may be a possibility, along with other
known power cycles, such as the organic-Rankine cycle.
Small to Medium Air-Cooled Commercial Chillers – All existing commercial
chillers, whether using waste heat, steam or natural gas, are water-cooled
(i.e., they must be connected to cooling towers which evaporate water into
the atmosphere to aid in cooling). This requirement generally limits the
market to large commercial-sized units (150 tons or larger), because of
the maintenance requirements for the cooling towers. Additionally, such
units consume water for cooling, limiting their application in arid
regions of the U.S. No suitable small-to-medium size (15 tons to 200 tons)
air-cooled absorption chillers are commercially available for these U.S.
climates. A small number of prototype air-cooled absorption chillers have
been developed in Japan, but they use “hardware” technology that is
not suited to the hotter temperatures experienced in most locations in the
United States. Although developed to work with natural gas firing, these
prototype air-cooled absorption chillers would also be suited to use waste
heat as the fuel.
Recovery of Waste Heat in Cogeneration
and
Trigeneration Power Plants
In most cogeneration and
trigeneration power and energy systems, the exhaust gas from the electric
generation equipment is ducted to a heat exchanger to recover the thermal
energy in the gas. These heat exchangers are air-to-water heat exchangers,
where the exhaust gas flows over some form of tube and fin heat exchange
surface and the heat from the exhaust gas is transferred to make hot water
or steam. The hot water or steam is then used to provide hot water or
steam heating and/or to operate thermally activated equipment, such as an absorption
chiller for cooling or a desiccant dehumidifer for dehumidification.
Many of the waste heat
recovery technologies used in building co/trigeneration systems require
hot water, some at moderate pressures of 15 to 150 psig. In the cases
where additional steam or pressurized hot water is needed, it may be
necessary to provide supplemental heat to the exhaust gas with a duct
burner.
In some applications
air-to-air heat exchangers can be used. In other instances, if the
emissions from the generation equipment are low enough, such as is with
many of the microturbine technologies, the hot exhaust gases can be mixed
with make-up air and vented directly into the heating system for building
heating.
In the majority of
installations, a flapper damper or "diverter" is employed to
vary flow across the heat transfer surfaces of the heat exchanger to
maintain a specific design temperature of the hot water or steam
generation rate.
Typical Waste
Heat Recovery Installation
In some co/trigeneration
designs, the exhaust gases can be used to activate a thermal wheel or a
desiccant dehumidifier. Thermal wheels use the exhaust gas to heat a
wheel with a medium that absorbs the heat and then transfers the heat when
the wheel is rotated into the incoming airflow.
A professional engineer should
be involved in designing and sizing of the waste heat recovery section.
For a proper and economical operation, the design of the heat recovery
section involves consideration of many related factors, such as the
thermal capacity of the exhaust gases, the exhaust flow rate, the sizing
and type of heat exchanger, and the desired parameters over a various
range of operating conditions of the co/trigeneration system — all of
which need to be considered for proper and economical operation.
Please
contact us for more
information, please call us at 832-758-0027.
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