Fossil Fuels and Fossil Energy

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Fossil Fuels and Fossil Energy

• Asim Zia
• Environmental Studies 133
• Alternative Energy Strategies
• San Jose State University
• Spring 2008

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Overview

• Definition and Types of fossil fuels
• Resource base how long?
• Harvesting energy (products) from fossil fuels?
• Environmental impacts
• Geopolitical and sociological factors
• Economics
• Evaluation principles/criteria
• Emerging technologies

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Definition and Types of fossil fuels

• A fossil fuel is a substance that releases energy
  by a chemical reaction (typically oxidation)
• CH4 2O2 -? CO2 2H2O
• Difference between combustors/burners (chemical)
  and fuel cells (electrochemical)
• Difference between fossil and biomass sources

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Definition and Types of fossil fuels (By Gross
Heating Value)

• Coal (1 kcal/g)
• Hydrogen (33.9 kcal/g) Carrier
• Methane (13.3 kcal/g)
• Natural Gas (11.7 kcal/g)
• Petroleum (10-11.4 kcal/g)
• Oil shale (10.3 kcal/g)
• Tar sands (5.5-8.8 kcal/g)

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Definition and Types of fossil fuelsDominance of
Fossil Fuels

• Maturity and size of fossil industry
• Existing infrastructure
• Attractive Economics

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Definition and Types of fossil fuelsDominance of
Fossil Fuels
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Resource base how long?

• Ignorance about when wed run out of fossils
• Ultra-heavy (high specific gravity) oil and
  natural gas hydrate deposits are largely
  unexploited
• Fossil fuel replenishment rate is slower than
  human consumption rate cross-scalar effects

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Resource base how long?
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Resource base how long?A sample problem

• Available time for resource (years) resource
  amount yet to be consumed/resource consumption
  rate per year
• E.g. coal yet to be consumed 275,000 x 1015 BTU
• Consumption rate 325.4 x 1015 BTU/yr
• Available time 275,000 x 1015 BTU/325.4 x 1015
  BTU/yr 846 years
• Caveat If resource consumption rate increases
  exponentially, available time will decrease
  exponentially too!!

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Resource base how long?Why sustainability
requires switch to alternative sources of energy?

• Not that the world is running out of fossil
  fuels p-305
• Global warming potential of GHG emissions from
  fossil fuels
• Smoother transition to lower fossil dependency
• Diversifying global sources of energy

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Harvesting energy (products) from fossil fuels?

• Exploration, discovery and extraction of fuels gtgt
  Technological improvements
• Fuel storage and transportation gtgt hazards and
  risks (oil spills)
• Fuel conversion or fuel processing is the
  chemical or physical transformation of a
  naturally occurring or already modified fuel to
  improve the quality of the fuel (i.e. higher H/C
  ratio)

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Harvesting energy (products) from fossil
fuels?Inputs and products of fuel conversion
processes
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Harvesting energy (products) from fossil
fuels?Petroleum refining Three Cs

• Compartmentalization e.g. fractional
  distillation of crude oil
• Conversion modification of chemical composition
  of fuels to instill desired properties
• Cleaning removal of pollutants

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Harvesting energy (products) from fossil
fuels?Coal Pyrolysis Carbon-rejection
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Harvesting energy (products) from fossil
fuels?Coal Gasification Chemistry
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Harvesting energy (products) from fossil
fuels?Coal Gasification Products
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Harvesting energy (products) from fossil
fuels?Coal Gasification Products
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Harvesting energy (products) from fossil
fuels?Fuel Combustion
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Harvesting energy (products) from fossil
fuels?Gas Turbine- Steam Turbine Combined Cycle
60 efficient
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Harvesting energy (products) from fossil fuels?
Typical coal plant 35 efficient
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Harvesting energy (products) from fossil fuels?
Pressurized fluid bed combined cycle 50
efficient
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Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Designs
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Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Chemistry
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Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Technologies
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Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Limitations

• Electricity generation limits stacks!

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Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Limitations

• Fuel Cell performance changes with the load
  demand on the cell and degrades at high loads

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Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Limitations

• Capital cost reduction needed
• Long-term durability (especially challenging
  environments such as automobiles)
• Fuel compatibility with the cell
• Provide H2 from storage But then which fuel will
  be used to generate H2?
• Provide H2 in situ This will require mating a
  fuel production technology, and a fuel, e.g.
  gasoline, diesel, or natural gas?
• Electrodes and electrolytes must be protected
  from poisoning

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Environmental impacts

• The fuel as a pollutant source
• Products of incomplete combustion
• Fuel impurities
• The combustion equation eq. 7-21 shows CO2 and
  other pollutants as products of combustion Age
  of Pyromania!
• Combustion pathologies

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Environmental impactsCarbon Management
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Geopolitical and sociological factors

• Oil importing countries dependencies
• Oil exporters price and quantity control
• Who will win and loose in carbon management
  policy regimes?
• Equity issues between developed and developing
  countries
• Oil revenue scaffolds

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Geopolitical and sociological factors

• Oil revenue scaffolds

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Economics
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Economics
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Economics
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Economics
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Evaluation principles/criteria

• Environmental performance
• Overall footprint, aesthetic impacts, air and
  water emissions, solid wastes, occupational
  safety
• Efficiency
• Energy efficiency and energy balances, material
  balances, technical feasibility, waste
  minimization, recycling potential
• Economics

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Emerging fossil fuel technologies