Title: Fossil Fuels and Fossil Energy
1Fossil Fuels and Fossil Energy
- Asim Zia
- Environmental Studies 133
- Alternative Energy Strategies
- San Jose State University
- Spring 2008
2Overview
- 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
3Definition 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
4Definition 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)
5Definition and Types of fossil fuelsDominance of
Fossil Fuels
- Maturity and size of fossil industry
- Existing infrastructure
- Attractive Economics
6Definition and Types of fossil fuelsDominance of
Fossil Fuels
7Resource 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
8Resource base how long?
9Resource 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!!
10Resource 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
11Harvesting 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)
12Harvesting energy (products) from fossil
fuels?Inputs and products of fuel conversion
processes
13Harvesting 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
14Harvesting energy (products) from fossil
fuels?Coal Pyrolysis Carbon-rejection
15Harvesting energy (products) from fossil
fuels?Coal Gasification Chemistry
16Harvesting energy (products) from fossil
fuels?Coal Gasification Products
17Harvesting energy (products) from fossil
fuels?Coal Gasification Products
18Harvesting energy (products) from fossil
fuels?Fuel Combustion
19Harvesting energy (products) from fossil
fuels?Gas Turbine- Steam Turbine Combined Cycle
60 efficient
20Harvesting energy (products) from fossil fuels?
Typical coal plant 35 efficient
21Harvesting energy (products) from fossil fuels?
Pressurized fluid bed combined cycle 50
efficient
22Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Designs
23Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Chemistry
24Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Technologies
25Harvesting energy (products) from fossil
fuels?Direct Generation of Electricity Fuel
Cell Limitations
- Electricity generation limits stacks!
26Harvesting 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
27Harvesting 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
28Environmental 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
29Environmental impactsCarbon Management
30Geopolitical 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
31Geopolitical and sociological factors
32Economics
33Economics
34Economics
35Economics
36Evaluation 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
37Emerging fossil fuel technologies