Module 02

1

• Module 02
• Conventional Energy Technologies
• - in electricity generation from non-renewable
  energy sources
• (coal, petroleum, natural gas and nuclear power)
• - in vehicular transport
• - in other primary and secondary energy
  consumption modes
• (heating, cooling, agriculture and electronic
  devices)

2
How is electricity generated from non-renewable
energy sources (oil, coal or natural gas)?
Combined Power Plant (GT ST)
Diesel Generator
Gas Turbine (GT)
Steam Turbine (ST)
3
Electric Generator
We need a rotating shaft?
How to rotate the wire loop?
http//electron9.phys.utk.edu/phys136d/modules/m8/
images/gen.gif
4
Wind turbine gives a rotating shaft
http//www.electricityforum.com/images/motor-eout.
gif
5
Water turbine could also give a rotating shaft
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Diesel generator
It is a diesel engine coupled to a electric
generator. Diesel engine provides the rotating
shaft.
http//www.rkm.com.au/animations/animation-diesel-
engine.html
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Diesel generator
It is a diesel engine coupled to a electric
generator. Diesel engine provides the rotating
shaft.
http//www.rkm.com.au/animations/animation-diesel-
engine.html
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Diesel generator
http//www.myrctoys.com/engines/ottomotor_e.swf
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Gas Turbine Power Plant
fuel
hot gases
Combustion Chamber
compressed air
Comp- ressor
Gas Turbine
Gen
fresh air
gases to the stack
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Gas turbine to produce electricity
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Gas turbine driving a jet engine
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Gas Turbine Power Plant
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Gas Turbine Power Plant
fuel
hot gases
Combustion Chamber
compressed air
Comp- ressor
Gas Turbine
Gen
fresh air
gases to the stack
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Gas Turbine Power Plant
fuel
hot gases
Combustion Chamber
compressed air
Comp- ressor
Gas Turbine
Gen
fresh air
gases to the stack
Useful work output ?
Total heat input ?
Total energy loss ?
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Gas Turbine Power Plant
Useful work output
-
goes to electricity generation
Total heat input
comes with the fuel
Thermal efficiency of the GT power plant
-
?thermal

16
Gas Turbine Power Plant
-
?thermal




-

-

for 50 to 100 MW plant
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Heat engine converts heat into work
Hot reservoir at TH K
Wout
?thermal

Qin
Qin
TC
-
Wout
?Carnot
1

TH
Qout
?Carnot
?thermal
lt
Cold reservoir at TC K
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Gas Turbine Power Plant
Carnot efficiency of the GT power plant
Lowest temperature (exhaust gas temperature)
TC
?Carnot
1 -

TH
Highest temperature (combustion chamber
temperature)
Maximum possible work output
?Carnot

Total heat input
?Carnot

Maximum possible work output
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Gas Turbine Power Plant
Second-law efficiency of GT power plant
Useful work output

Maximum possible work output
?thermal

?Carnot
?thermal

lt 1
?Carnot
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Steam turbine
http//www.bizaims.com/files/generator.JPG
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Steam Turbine Power Plant
Steam Turbine
Gen
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Steam Turbine Power Plant
hot gases
superheated steam
compressed water
Steam Generator
Steam Turbine
C
Pump
Gen
Condenser
saturated water
saturated steam
cooling water
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Steam turbine to produce electricity
Oil could be used instead of coal.
R. Shanthini 15 Aug 2010
Steam engines are also used to power the train.
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Steam Turbine Power Plant
hot gases
superheated steam
compressed water
Steam Generator
Steam Turbine
C
Pump
Gen
Condenser
saturated water
saturated steam
cooling water
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Steam Turbine Power Plant
-
(WP)
?thermal
in




-
-
(WP)

in

for 200 to 800 MW plant
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Combined Power Plant
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Combined Power Plant
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Combined Power Plant
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Combined Power Plant
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Combined Power Plant
Useful work output at GT ST
?thermal

Heat released by fuel
36 50


for 300 to 600 MW plant
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Nuclear Power Plant
Containment
CORE
Control rods
PWR
Pressurized water
C
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Nuclear power plant to produce electricity
R. Shanthini 15 Aug 2010
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Nuclear Power Plant
Useful work output at ST
?thermal

Heat released by fuel

31 34

for 500 to 1100 MW plant
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According to the 2nd Law of Thermodynamics when
heat is converted into work, part of the heat
energy must be wasted
Power generation type Unit size (MW) Energy Wasted (MW)
Diesel engine 10 - 30 7 22
Gas Turbine 50 - 100 36 78
Steam Turbine 200 - 800 120 560
Combined (ST GT) 300 - 600 150 380
Nuclear (BWR PWR) 500 - 1100 330 760
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50 - 70 lost in producing electricity
2 - 20 lost in transmitting electricity
Generation, transmission and end-use losses
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Typical energy losses in an industrialised country
Electric power sector
70 energy losses
Transportation sector
80 energy losses
Residential Commercial sector
25 energy losses
Industrial sector
20 energy losses
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Discussion Point Why oil, coal, natural gas and
nuclear fuel are unsustainable?
38
Sustainable energy is energy which is
replenishable within a human lifetime and causes
no long-term damages to the environment.
Source http//www.jsdnp.org.jm/glossary.html
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Nuclear Energy
Source BP Statistical Review of World Energy
June 2008
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Nuclear Energy
Source BP Statistical Review of World Energy
June 2008
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Nuclear Energy
Technological status mature
Average growth 0.7 per year
Total share of global energy mix 16 of electricity in 2007 10 of electricity in 2030 (potential)
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Nuclear Energy
An isotope of Uranium, 235U, is used as the
reactor fuel. A neutron striking a 235U nucleus
gets absorbed into it and 236U is created. 236U
is unstable and this causes the atom to fission.
The fissioning of 236U can produce over twenty
different products. Eg 235U 1 neutron
3 neutrons 89Kr 144Ba ENERGY Examples
of fission products 90Sr and 137Cs (half-life
30 years) 126Sn (half-life of 230,000 years, but
low yield)
43
Nuclear Energy
Heat to Work paradigm
Source http//www.cameco.com/uranium_101/uranium_
science/ nuclear_reactors/
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Nuclear Energy
Nuclear fission provides 16 of the world
electricity production and 7 of the total energy
consumption. Current usage of uranium is about
65,000 t/yr.  The world's present measured
resources of uranium in the cost category
somewhat below present spot prices is about 5.5
Mt. They could last for over 80 years at the
current usage rate. Nuclear energy is therefore
not a renewable energy source. 
Source http//www.world-nuclear.org/info/inf75.ht
ml
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Nuclear Energy
Nuclear waste and the retired nuclear plants
could remain radioactive for hundreds of future
generations. Uranium is available on earth only
in limited quantities. Uranium is being converted
during the operation of the nuclear power plant
so it won't be available any more for future
generations. Therefore nuclear power is not a
sustainable source of energy.
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Fusion Energy
The D-T Fusion Reaction Nuclei of two isotopes
of hydrogen, naturally occuring deuterium (2H)
and synthetically produced tritium (3H) react to
produce a helium (He) nucleus and a neutron (n).
In each reaction, 17.6 MeV of energy (2.8 pJ)
is liberated 2H     3H     4He (3.5
MeV)     n (14.1 MeV)
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Fusion Energy
Sun energy comes from the fusion of hydrogen into
helium. It happens at very high temperatures
generated owing to the massive gas cloud
shrinking under its own gravitational force.
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Fusion Energy
Technological status research phase
Major challenge make ITER (International Thermonuclear Experimental Reactor) a success
Major barrier immense investments in research and development are needed
Total share of global energy mix 0 of electricity in 2007
Possible adverse effects worn-out reactors will be radioactive for 50-100 years, but there is no long-lived radioactive waste
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Combustion Engine
The combustion engine is used to power nearly
all land vehicles and many water-based and
air-based vehicles. In an internal combustion
engine, a fuel (gasoline for example) fills a
chamber, then it is compressed to heat it up,
and then is ignited by a spark plug, causing
a small explosion which generates work.
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Combustion Engine
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Vehicles mostly uses Internal Combustion Engines
TH
Flame temperature (800oC)
TC
Exhaust Temperature (40oC)
313 K

-
1
1073 K
Carnot

71
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A user of a car always asks for some minimum
requirements while using a car. - The drive
should be smooth and easy. - The car should
maintain a good speed so as to cope up with other
cars in traffic. - Easy and fast refuelling of
cars. - A good mileage - Less pollution
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A Typical Car
Urban Driving
Engine losses in fuel energy conversion, In
engine cooling and with exhaust gases
63 kJ
Driveline losses
6 kJ
Fuel Energy
18 kJ
Aerodynamic drags
2.5 kJ
100 kJ
12 kJ
Rolling resistance
4 kJ
17 kJ
Standby Idle
5.5 kJ
Braking
Energy for accessories
2 kJ
Source http//www.fueleconomy.gov/feg/atv.shtml
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A Typical Car
Highway Driving
Engine losses in fuel energy conversion, In
engine cooling and with exhaust gases
69 kJ
Driveline losses
5 kJ
Fuel Energy
25 kJ
Aerodynamic drags
11 kJ
100 kJ
20 kJ
Rolling resistance
7 kJ
4 kJ
Standby Idle
2 kJ
Braking
Energy for accessories
2 kJ
Source http//www.fueleconomy.gov/feg/atv.shtml
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Electric Car
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Electric Car
http//www.esb.ie/electric-cars/environment-electr
ic-cars/how-green-are-electric-cars.jsp
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Hybrid Car
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Hybrid Car
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Hybrid Car

• Advantages Of Hybrid Cars
• Better mileage (claimed).
• More reliable and comfortable (claimed).
• Lesser GHG emissions.
• Batteries need not be charged by an external
  source.
• Warranties available for batteries as well as
  motors.
• Less dependence on fuels.

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Hybrid Car

• Disadvantages Of Hybrid Cars
• The initial cost is higher.
• Car is heavier (110).
• Risk of shock during an accident.
• The vehicle can be repaired only by
  professionals.
• Spare parts will be very costly and rare.
• Uses more rare metals (nickel metal hydride
  batteries and more copper wires)
• Highway driving works the IC engine and not on
  the battery.

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Bio-ethanol as an alternative fuel
Bioethanol is produced from plants that harness
the power of the sun to convert water and CO2 to
sugars (photosynthesis), therefore it is a
renewable fuel.
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Bio-ethanol as an alternative fuel
Bioethanol is produced from plants that harness
the power of the sun to convert water and CO2 to
sugars (photosynthesis), therefore it is a
renewable fuel.
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A growing number of cars and trucks designated as
FlexFuel Vehicles (FFV) can use ethanol blended
up to 85 with petrol (E85 fuel). Today there
are more than 6 million FFV's on U.S. roads
alone.
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Source http//www.distill.com/World-Fuel-Ethanol-
AO-2004.html
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Bioethanol from simple sugars
Sugar cane and sugar beets store the energy as
simple sugars, glucose (C6H12O6)
yeast
2 CH3CH2OH
2 CO2
this simple-looking reaction is a bioreaction and
thus very complex
impure cultures of yeast produce glycerine and
various organic acids
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Yeast can be replaced by the bacterium Zymomonas
mobilis - gives up to 98 yields -
minimal by-products - simple fermentation
requirements - several-fold the production
rates of yeast
Z. mobilis industrial strain CP4, originating
from Brazil, vigorously fermenting glucose.
Photo courtesy Katherine M. Pappas
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sugar cane
sugar cane residue
sugar cane crushed and soluble sugar washed out
CO2
yeast
fermentation of sugars produces 5 - 12 ethanol
wet solids
distilled to concentrate to 80 95 ethanol
dehydrate to 100 ethanol
used as a petrol replacement
used as a petrol additive
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Bioethanol from starch
Corn, wheat and cassava store the energy as more
complex sugars, called starch

starch (glucose polymer)
a-amylase
dextrins
amyloglucosidase
glucose monomer
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cassava flour water alpha-amylase enzyme
Liquification (at 90 95 deg C pH 4 - 4.5
400 rpm)
Saccharification with glucosidase enzyme (at 55
- 65 deg C, pH 4 - 4.5)
Fermentation with yeast (40 50 hrs)
Cooling (32 deg C)
Distillation
Dehydration
80-95 ethanol
100 ethanol
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Bioethanol from Biomass (except sugars and
starches)
Rice straw Paddy husks Saw dust Grasses Bagasse
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Bioethanol from Biomass (except sugars and
starches)
Cellulose (40 to 60 by weight of the biomass)
made from the six-carbon sugar, glucose. Its
crystalline structure makes it resistant to
hydrolysis (the chemical reaction that releases
simple, fermentable sugars).
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Currently, bioethanol yields 25 more energy
output than input to produce it.

• Because fossil fuel is required
• for the tractor planting the corn
• for the fertilizer put in the field
• for the energy needed at the processing plant

Bioethanol also requires land and water.
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Is bioethanol a sustainable energy source?
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Bioethanol will be used in engines that convert
heat into work
Engines that convert heat into work are very
inefficient
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Biofuels, such as US corn bioethanol, Brazilian
sugar cane bioethanol, Brazilian soy biodiesel
and Malaysian palm-oil biodiesel, have greater
total environmental impacts than fossil fuels.
Andy Tait of Greenpeace said "It is clear that
what government and industry are trying to do is
find a neat, drop-in solution that allows people
to continue business as usual. If you are looking
at the emissions from the transport sector, the
first thing you need to look at is fuel
efficiency and massively increasing it. That
needs to come before you even get to the point of
discussing which biofuels might be good or bad."
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(No Transcript)
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Heating
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Cooling air conditioning
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Cooling refrigeration
80
Agricultural machinery