coal and natural gas
Post on 18-Dec-2021
1 Views
Preview:
TRANSCRIPT
2
2005 Annual Production in ZettaJoules
Data Source: World Energy Council: 2007 Survey of World Energy Reserves
Total Annual Production 0.459 ZettaJoules
Coal
32%
Crude Oil
40%
Shale Oil
0%
Natural Bitumen
0%
Extra Heavy Oil
0%Natural Gas
23%
Uranium
5%
Coal
Crude Oil
Shale Oil
Natural Bitumen
Extra Heavy Oil
Natural Gas
Uranium
Production of non Renewable
Energy Resources
Source: K. Gaughan calculation from World Energy Council data
3
World Primary Energy Production
including Renewables
Source: World Coal Institute http://www.worldcoal.org/pages/content/index.asp?PageID=188
accessed 12 Nov 2007
4
Reserves:
122
0.459
55.94
All Non Renewables
79
0.025
1.95
Uranium
63
0.107
6.71
Natural Gas
261
0.001
0.37
Extra Heavy Oil
665
0.002
1.51
Natural Bitumen
565200
0.000
17.29
Shale Oil
41
0.181
7.43
Crude Oil
145
0.142
20.68
Coal
Years
left at
current
producti
on
Annual
Production
in
ZettaJoules
Reserves in
ZettaJoules
(10E21J)
Resource
5
Coal
•History of Coal
•Where is coal found?
•Coal Reserves
•Combustion of Coal
•Uses of Coal
•Coal Prices
•Reference: Boyle , Everett, RamageEnergy Systems and Sustainability
•Reference: World Coal Institute: http://www.worldcoal.org
6
“Coal is a fossil fuel. It is a combustible, sedimentary,
organic rock, which is composed mainly of carbon,
hydrogen and oxygen. It is formed from vegetation,
which has been consolidated between other rock strata
and altered by the combined effects of pressure and heat
over millions of years to form coal seams.”
World Coal Institute: http://www.worldcoal.org
7
Brief History of Coal Use
•From Bronze Age times coal has been used as a fuel for heating, cooking and
lighting
•In Elizabethan times the poularityof coal grew alongside the poularityof brick
buildings. From 17thcentury concerns about atmospheric pollution from coal
fires.
•1709 –Darby’s use of coke (coal product) as a substitute for charcoal in
smelting of iron.
•Industrial revolution (circa 1700 –1850) explosive rise in demand for coal as
fuel and as input to smelting of iron.
•Coal remained the dominant worlwidecommercially traded fuel source right
up to 1960’s when oil overtook coal primarily due to rise in transportationuse.
•Although the relative importance of coal fell coal production continued to
grow steadily up to 1990.
•The 1990’s were a period of stable coal production but has grown rapidly since
2000 due to the explosive growth in demand of the Chinese economy China
since entry to WTO in 2001.
10
Source: World Coal Institute
http://www.worldcoal.org
2006 Hard Coal Production Total Global Consumption: 5370Mt (estimate)
PR China
49%
USA
19%
India
8%
Australia
6%
South Africa
5%
Russia
5%
Rest of World
8%
PR China
USA
India
Australia
South Africa
Russia
Rest of World
Note in 2006 Brown Coal / Lignite accounts
for an additional 914Mt
11
Comment
•Coal Reserves are far more widespread than
Oil reserves
•On an energy basis coal reserves are far
greater than conventional oil reserves (not
including shale).
12
Chemistry and combustion of coal
•Ash Content varies from 10% to 30%. Ash is inert and remains behind
after combustion
•Typical dry Ash Free Coal by mass: Carbon 88%, Hydrogen 5%,
Oxygen 5%, Nitrogen 1%, Sulphur 1%
•Sulphur content varies up to 5%
•Combustion Products
–Carbon + Oxygen →Carbon Dioxide (C02). Incomplete combustion give
Carbon Monoxide (CO)
–Hydrogen + Oxygen →Water (H2O)
–Sulphur and nitrogen give rise to polluting sulphurous (SO2) and nitrous
oxides (NOX).
•On an equal energy basis Coal combustion produces significantly more
greenhouse gas than Oil or Natural gas.
14
Uses of Coal
•Electricity Generation: Approx 66%
•Iron and Steel: Approx 20%
•Direct use & Smokeless fuels: approx 10%
Source of estimates: Boyle Everett and Ramage.
16
Secondary Fuels Derived From Coal
•Coal Gas –a mixture of H2, CO and CH4 was a by-product of coke
production for the iron and steel industry. In the 19thcentury and first
half of the 20thcentury coal derived gas was widely used in the public
gas supply, in street lighting and for domestic use. Coal gas
distribution has been almost entirely supplanted by natural gas
(methane: CH4) but it is still used within the steel works.
•Pure methane can be produced from coal but there has been little
economic incentive to pursue this
•There are a number of liquefaction processes available which aimto
make a petrol substitute from coal: Fischer TropschProcess (used in
South African Sasol plants to produce 10000 barrels per day). Bergius
process extensively used in Nazi Germany (estimated 80000 barrels
per day).
17
Natural Gas
•History of fuel gases
•Location and Reserves of Natural Gas
•Chemistry of Natural Gas
•Uses of Natural Gas
Useful Reference:
Energy Information Administration Intern
ational Energy
outlook 2007: Chapter 4 N
atura
l Gas available online
http://www.eia.doe.gov/oiaf/ieo/nat_gas.html
18
Natural Gas Reserves
Images taken from: Energy Information Administration Intern
ational Energy outlook 2007: Chapter 4
Natura
l Gas available online http://www.eia.doe.gov/oiaf/ieo/nat_gas.htmlaccessed 12 Nov 2007
20
Questions
•Natural Gas was formed million of years ago. How come the graph of
natural gas reserves shows a continually increasing trend?
•Are there reasons why we may be further away from the time of “peak
gas”than from the time of peak oil?
•Is there a disparity between consumers of gas and producers of gas?
•Gas fields are often but not always found in conjunction with oil fields.
Are there similarities between the location of gas reserves and oil
reserves?
•Gas consumption is more concentrated in developed nations than oil
consumption. Why is this? What infrastructure is required for oil
consumption? What infrastructure is required for gas consumption?
•Is natural gas more likely to be used in an urban economy or a rural
economy?
21
History of Gas use
•Beginning of 19thcentury coal gas (town gas) a by product of coke
production for Iron and Steel industries was initallyused for street
lighting and eventually for domestic lighting, cooking and heating.
Soon dedicated gasworks were constructed to generate coal gas for
urban populations.
•In first half of 20thcentury electricity replaced gas for lighting but coal
gas was still in widespread use for domestic heating and cooking
•Natural Gas deposits originally discovered in conjunction with Oil.
•Natural Gas networks were established in USA in 1950’s and in
Europe in the 1960’s.
•Natural gas requires no conversion process and was adopted as a clean
/ safe replacement for coal gas. Coal gas rapidly fell out of favour.
•Natural gas use rose dramatically in later half of 20thcentury for
residential heating, for industrial heating and for electricity generation.
22
Chemistry of Natural Gas
•Raw Natural Gas: 70-90% Methane CH4 5-15% Ethane
C2H6+ other impurities
•Raw Gas is processed to remove impurities (including
some commercial by products) and increase the
percentage of methane for fuel use (Pipeline Quality Gas).
•Methane+Oxygen→CarbonDioxide (CO2) and Water
(H2O)
•Methane and its combustion products are odourless and
colourless but as a safety precaution minute amounts of
odourant(mercaptan) may be added.
23
Source: EIA The Cru
cial Link Between N
atura
l Gas Production
and Its Tra
nsp
ortation to M
arket available online at http://www.eia.doe.gov
25
Electricity Generation From Gas
•In many countries Gas has displaced Oil from electricity
GenerationThekey drivers are:
–Cost: Gas is historically cheaper than oil. It is considerably dearer than
coal but some of that difference is offset by efficiency.
–Efficiency: Combined cycle gas turbines offer efficiencies approaching
60% while tradionalopen cyleplants are closer to 40% efficient
–Cleanliness –Natural gas has lower emissions than oil and significantly
lower emissions than coal.
•Example
–Open Cycle Gas Turbine firing temperature 1200°C final exhaust
temperature 500°.Theoretical maximum Efficiency (Carnot Efficiency) =
47%
–Combined Cycle Turbine Firing temperature 1200°C, Final Exhaust
temperature 100°C. Theoretical Maximum Efficiency (Carnot Efficiency)
= 74%
–
28
Questions
•Give possible reasons why the price of Oil
Risen dramatically since 2000
•Investigate why the price of gas is closely
linked to the price of oil
•Why is the price of coal not linked more
closely to the price of oil?
29
Gas / Oil Price Links
•The price of gas tracks the price of oil closely.
•Economics would suggest that if the market is operating efficiently then this
close tracking would indicate that gas and oil are close substitutes for each
other.
–Both fluid fuels: can both be used in turbines and boilers
–The replacement of oil by gas in electricity generation indicates that gas can indeed
substitute for oil in many cases
–Natural Gas cannot be used in transportation –which may explain the slight
premium that oil has historically attracted on an equal energy basis
•The price of coal does not track the price of oil as closely as natural gas.
Possible reasons include:
–Conversion Efficiency –Gas and oil combustion is generally more efficient than
coal combustion
–Environmental “externalities”being reflected in the price of coal
–Possible Reasons for Market Failure:
•High Switching costs (coal is not a fluid)
•Possible seller collusion (the sellers of gas and sellers of oilare closely related)
top related