Natural Gas

1
Natural Gas

• A cleaner solution for the future?

2
General Information

• Natural gas currently costs 11.25 per MMBTU. A
  year ago the price was 7. The price peaked at
  15 in October.
• Permits and local opposition are the two hurdles
  for improvements to the infrastructure.
• There are approximately 270,000 miles of
  pipelines for the transport of natural gas in the
  United States.
• Natural gas is available to approximately 60 of
  all US homes. Residential use of natural gas
  accounts for 22 of all natural gas consumption.
• Natural gas provided 23 of all US energy in 2003.

3
Natural Gas Uses

• Electricity Generation 17 of all US electricity
  is generated by natural gas.
• Fertilizer Production. 5 of all natural gas
  consumption is from production of fertilizers.
• Home Heating and Cooking.

4
Infrastructure

• Distribution
• Compressor stations, typically located every 50
  miles, keep the pressure of the pipeline are a
  pre-determined level. The compressor stations
  consume some of the natural gas to maintain the
  pressure. Distribution consumes approximately 650
  million cubic feet of natural gas each year. This
  is only 3 of the total consumption of natural
  gas in the United States.
• Storage
• Natural gas must be stored to meet peak demand
  and to hold excess natural gas production from
  wells. Natural gas is primarily stored in three
  underground formations salt caverns, depleted
  oil and natural gas fields, and aquifers.
  Depleted oil and natural gas fields provide the
  major of storage capacity, 6.73 tcf for 2003.
  Aquifers provide the next most storage at 1.23
  tcf for 2003. There are approximately 400
  underground storage areas for natural gas in the
  United States.

5
Infrastructure Cont.

• Linepack is another storage technique. Linepack
  is the storage of natural gas in the pipelines
  themselves.
• A 50-mile section of 42-inch transmission line
  operating at about 1,000 psi contains about 200
  million cubic feet of gas. This storage method
  allows for natural gas to remain available even
  with changes in demand.

6
The Future Infrastructure

• Pipeline inspection robots.
• Storage well cleaning tools.
• Increasing storage densities by cooling the gas.
• Storage via artificial methane hydrates.

7
Safety and the Environment

• Leaks additives to smell any gas leak.
• Environmental Impact of Natural Gas
• In power plants, natural gas produces nearly half
  as much CO2 as coal and only 2/3rds as much CO2
  as oil.
• 2.8 percent of all CO2 emissions in 2003 were
  from flaring natural gas.
• Avoiding leaks in natural gas storage and
  transportation will reduce the amount of methane
  that enters the atmosphere.
• Natural gas releases small amounts of pollutants
  when burned. However, natural gas does not
  release mercury and sulfur dioxide like oil and
  coal. The amount of nitrogen compounds released
  by natural gas are about 2-4 times less than coal
  and oil.

8
Natural Gas Exploration

• Before 1800, the only way of discovering gas or
  oil was seepage of oil above ground
• Discovery in the early 1800s found that
  anti-clinal slopes usually had gas under them
• Tests would determine porosity and permeability
  of the area to further determine the probability
  of the deposit
• Now seismic and magnetic field testing are mostly
  used. Seismic waves are sent through the earth
  and there echoes are analyzed for velocity
  changes to find deposits

9
Liquid Natural Gas (LNG)

• LNG makes up 6 of US gas imports and is growing
• The US has LNG terminals at Everett,
  Massachusetts Cove Point, Maryland Elba Island,
  Georgia Lake Charles, Louisiana and Peñuelas,
  Puerto Rico.
• LNG is not a new fuel, but rather an alternative
  transportation method.

10
Natural Gas Liquefaction

• Natural gas is cooled to -260 F to form LNG.
• All impurities are removed from the natural gas
  before liquefaction.

11
LNG Transportation and Processing

• LNG is transported by ocean tanker.
• The tankers are insulated. The small amount of
  LNG that returns to gas form is used to fuel the
  tanker.
• Upon arrival at a LNG terminal, the liquid is
  gradually heated to room temperature to form
  natural gas.

12
LNG Safety

• A rapid phase transition of spilled LNG can cause
  limited local damage.
• The cryogenic temperatures of LNG are harmful if
  LNG comes into contact with a human.
• As LNG from any spill evaporates, it can explode
  if the methane concentration is 5-15.

13
LNG Safety Cont.

• LNG is stored under atmospheric pressure so there
  is no risk of an explosive release of LNG or a
  rapid spill.
• LNG is non-toxic and non-corrosive. However, it
  evaporates to a colorless/odorless gas that can
  cause asphyxiation.

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LNG Safety Measures

• All LNG tankers have double hulls to protect
  against spills. In addition, the hull can help
  contain any spill. Inert gases are in areas below
  deck to reduce the risk of any ignition.
• Buffer zones of up to 1 mile around LNG terminals
  offer additional protection in the unlikely case
  of a large explosion.

15
A Future for Natural Gas

• The Alaska Pipeline
• Microturbines
• Methane Hydrates
• Combined Cycle Natural Gas Power Plants
• A Transportation Fuel

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The Alaska Pipeline
17
Pipeline Benefits

• 65 billion for Alaska and Canada by 2020
• 1 million jobs created during the 10 year
  construction
• Increase domestic supplies of natural gas

18
Pipeline Risks

• The current natural gas market is subject to
  fluctuations.
• Any investment in the Alaska pipeline could go
  bad if gas prices fall during or after
  construction.
• The government could shoulder part of the risk by
  securing the investments in the pipeline should
  prices fall.
• The pipeline could disrupt ecosystems.

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Pipeline Downsides

• 20 billion over 10 years
• Can only supply about 7 of current demand
• The US currently consumes 22 trillion cubic feet
  per year. The pipeline would be expected to
  deliver 1.5 trillion cubic feet per year.

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Microturbines

• Micro turbines are an effective implementation of
  cogeneration of electricity.
• Hot exhaust from the turbine can be used to heat
  homes and business
• Mass production of microturbines could lead to
  reasonable equipment prices as well as improved
  efficiency.
• Home microturbines would be fueled by the
  existing natural gas infrastructure.

21
Methane Hydrates

• Locations At least 300m deep in cold waters
  along the Alaskan coast and the northeastern and
  western coast of the US.
• Formation
• By gas escaping from faults that reacts with the
  cold and dense water.
• By anaerobic bacteria breaking down organic
  matter.

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What are Methane Hydrates?

• Gas molecules held in a crystalline form when
  water forms an ice-like cage.
• A hydrate is also called a clathrate compound.
• 1 cubic meter of hydrate yields 163 cubic meters
  of methane.

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Methane Hydrate Uses and Problems

• Could be a source of natural gas for 2000 years.
• Synthetic hydrates could be used for carbon
  sequestration.
• However, mining the hydrates has proved to be
  very dangerous and expensive.

24
Combined Cycle Power Plants

• Combined Cycle Natural Gas (CCNG) plants have
  nearly doubled efficiencies of up to 60.
• First, the combustion of the natural gas runs a
  turbine that generates power.
• Second, the exhaust from the turbine heats water
  to create steam which generates power via a steam
  turbine.

25
Natural Gas for Transportation

• Natural gas is a reasonable alternative fuel for
  transportation when compressed.
• Home refueling stations using the existing
  natural gas infrastructure offers low cost
  distribution of fuels.
• A car powered by natural gas costs a few thousand
  dollars more than a gasoline powered car.

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Questions