Fossil fuels - conventional and advanced

Transcription

Fossil fuels - conventional and advanced
Energy resources - fossil fuels
Fall
Fossil Fuels
The development of sustainable energy
systems has ‘emerged as one of the
priority issues in the move towards
global sustainability’
(Malkina-Pykh et al., 2002)
“improving access to reliable, affordable,
economically viable, socially acceptable
and environmentally sound energy
services and resources, taking into
account national specificities and
circumstances through various means such
as enhanced rural electrification and
decentralized energy systems, increased
use of renewable energy, cleaner liquid
and gaseous fuels and enhanced energy
efficiency.”
(Johannesburg declaration)
Develop energy systems such that we balance
economic development with social and
environmental objectives
Social
Economic
Environmental
SED Themes/Goals
Four broad themes/goals towards SED:
•Improve technical and economic efficiency (Econ D)
•Improve energy security (supply and infrastructure);
diversifying, decentralize, increasing supply, local
sources, renewable (Econ D)
•Reduce environmental impact (environmental
dimension)
•Expand access and affordability (social dimension)
Multi-objective policy and decision-making
E.g. Energy and Environmental policy interlinked!
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Energy resources - fossil fuels
Fall
 Resource
Classification
to measure lifetime?
 Fossil Fuels, use and lifetime
 How
•
•
•
•
Conventional vs. unconventional
Oil
Natural Gas
Coal
 Environmental
 Advanced
impact
Use of Fossil Fuel Resources
In 2008, total worldwide energy consumption was
474 exajoules (474*1018 J = 132,000 TWh).
 85% fossil fuel

World Total Primary Energy Supply
Icel
and
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
Geothe
rmal
0.1%
Shares of energy sources in total global primary
energy supply in 2008 (492 EJ).
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Energy resources - fossil fuels
 For
 Renewable
resource: continuously
available or replenished quickly
• examples: sunlight, biomass, hydro-power
Coal
Natural
Oil
gas
 Primary
Years
fossil fuel at the
end of 2010
 Reserves to
production ratio (R/P)
Fall
energy
• Can be used almost directly, coal, oil, gas
 Secondary
energy
• Produced from primary energy e.g. electricity
 Alternative,
 Measured
conventional, unconventional
in e.g. TOE, Joules, BTU’s, kWh
 Non-renewable:
extracted at rate > than
replenishment rate
• examples: fossil fuels, nuclear fuels, metals
 Energy
intensity
• BTU energy/tons aluminum
 Energy
efficiency
• Tons aluminum/BTU´s energy
• Laws of thermodynamics! Quantity, quality
 EROI
• Energy out/Energy in
 Conservation
 Cogeneration
(e.g. NGCC, combined gas
and steam cycle – waste heat to produce
electricity)
 Efficiency change
 Oil
• Conventional (crude)
• Unconventional (Oil shale, Tar sands, Heavy crude)
 Natural
Gas
• Conventional
• Unconventional (Methane ice, coalbed methane)
 Coal
• Conventional
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Energy resources - fossil fuels
Fall
Origin





Organic matter is buried in anoxic marine basins in
tropical environments often in highly productive
areas
Incomplete biological decomposition, depth >500m
Buried organic material forms kerogen, a solid,
waxy organic material
Kerogen is converted to petroleum during burial at
temperatures of 50 to 100°C; up to 200°C for gas.
More heat and pressure - higher quality fuels.
Increasing pressure and heat - water pushed out,
upwards migration to reservoir rock, cap rock.
 Petroleum
migrates from source rock
(usually siltstone or shale) to reservoir
rock (usually more permeable)
 Oil will move to surface unless it hits an
oil trap
 Thus to get oil, we need a productive
area, lack of oxygen, high pressure and
heat, trapping structure
oil refinery is
an industrial process
plant where crude oil
is processed and
refined into useful
petroleum products
such as gasoline
and diesel fuel.
 Fractional distillation
 An
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 Primary
recovery
• 25-30%, flows out by own pressure
 Secondary
recovery
• 10%, flows out with help of gas or water
 Tertiary
recovery
• 10%, CO2 or NOx enhanced recovery
 Oil
Shale: brown-black sedimentary rock
consisting of kerogen (10%) and fine mineral
grains
• Surface or subsurface mining, vaporized
• 10 times oil reserves of the Middle East
• Environmentally harmful, expensive
 Tar
Sand: unconsolidated sand and silt with
bitumen
• Mining, vaporizing, high viscosity
• Expensive, environmentally harmful
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Energy resources - fossil fuels
Fall
 Peak
oil is the point or timeframe at which the
maximum global petroleum production rate is
reached, after which the rate of production
enters its terminal decline.
 If global consumption is not mitigated before the
peak, the availability of conventional oil will drop
and prices will rise, perhaps dramatically.
M. King Hubbert first used the theory in 1956 to
accurately predict that US oil production would
peak between 65 and 70.
 His model, now called Hubbert peak theory, has
since been used to predict the peak petroleum
production of many other countries
 According to the Hubbert model, the production
rate of a limited resource will follow a roughly
symmetrical bell-shaped curve based on the
limits of exploitability and market pressures.

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



Best first principle in
action
Discoveries peak, and
then production peaks
Peak defined by
physical scarcities - at
about mid-point
After peak, production
declines
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Energy resources - fossil fuels
Fall
 Natural
gas
• Mixture of 80 - 90% methane, smaller amount of
heavier hydrocarbon compounds
• Conventional - with oil
• Unconventional
 Coalbed methane
 Methane ice (>500m), marsh gas
 Aquifer gas
 Water
ice, that
contains methane
within its crystal
structure
 Frozen, or
crystallized storage
of methane
 Polar permafrost, in
ocean sediments
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Energy resources - fossil fuels
Fall
Origin:
•
Dead plants are buried in terrestrial
sediments
•
Heat, pressure and bacterial action and
lack of oxygen
•
First peat, then coal
•
Anthracite, bituminous, lignite
 In
order of
increasing energy
content:
1.Peat
2.Lignite (low sulfur)
3.Bituminous (high S)
4.Anthracite (low-med
sulfur)
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Energy resources - fossil fuels
 Electricity
• Increase efficiency of power/electricity generation
Fall
 Cogeneration(steam-electricity)
–
polygeneration (steam, electricity, synfuels).
and use less coal more natural gas
 A) Large scale (Coal) – IGCC.
 B) Small scale (Natural gas) - NGCC - can be deployed at a
much smaller scales from 1 to several hundred megawatts).
 Clean coal
 Cogeneration with industry
• Use cogeneration – polygeneration - synfuels
 Transportation
• Towards use of electricity, hydrogen, biofuels,
synfuels
• Other advanced transportation tech. e.g. hybrids
Increase the Efficiency of Power/electricity
generation, and use more gas.
• Gas Driven Turbines
Advantages:
 Are as efficient as the coal driven ones
 NOx the only real pollution (and CO2 of course) and is only 10% of
coal fired power plants.
• Disadvantages:
 A bit more expensive
 Inertia prevents investment
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 Increase
fuel efficiency - only about 8%
efficiency, use lighter cars
 Use Alternative Fuels
•
•
•
•
Hybrids cars: Use a mixture of electricity and gasoline.
Electric cars: Plug - in
Biofuels: Such as ethanol, methane, biodiesel
Synfuels – or syngas derived fuels:
 Synthetic middle distillates (SMD)
 Dimethyl ether (DME)
• Hydrogen as an energy carrier – fuel cells
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Energy resources - fossil fuels
 Recovery:
damage to fragile
ecosystems, water and air pollution, and
waste disposal
 Refining: soil, water and air pollution
 Delivery and Use: energy to power
automobiles, produce electricity, etc.
Fall
 Household
Scale
• Carbon monoxide
 Local
(community) Scale
• Fuel-derived air pollution/urban pollution.
 Electric Power sector - particles, NOx and SOx, lead e.g.
Local pollution
 Car exhaust - Small particles, NOx, SOx, VOC - Smog
• Oil Spills: impact on water and terrestrial
ecosystems, very difficult to clean.
• Local impact from extraction
 Regional
scale
• Acid Rain
 Global
Scale
• Climate change
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