Transcript Document

Energy Conclave - 2006
Frontiers in Technologies and Modernization
Dr.R.R.Sonde
Executive Director (Energy Technologies)
NTPC Ltd
N.Delhi
July’ 2006
28th
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Electricity, the future form of energy
 Electricity is going to be the main stay of Energy
 Transport sector could see a major change from natural liquid hydrocarbon
to either Electricity, Hydrogen or Synthetic Liquid Fuel
Primary Energy (mtoe/yr)
 Rural prosperity would see a major shift from the usage of non-commercial
energy to electricity
500
450
400
350
300
250
200
150
100
50
0
1950
Non Commr
Import
Wind
Nuclear
Hydro
Natural Gas
Oil
Lignite
1960
1970
1980
1990
2000
Coal
Coal / Biomass and water would be physical form of fuel outside ‘fusion’
Solar is going to be the riding source of “energy”
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However, for this to happen, electricity has to be affordable, available and clean
 Cheap Power : High Efficiency (from mine to delivery)
 Abundant Power : Plentiful so that it powers the country’s growth
 Clean Power : Environmentally Benign
Efficiency
90
Efficiency [%]
80
Penalty
for
CCS
(Carbon Capture &
Seq) would be 10%
points
over
and
above the indicated
efficiency figures
70
60
50
40
30
20
SubSuperCritical Critical
Comb
Cycle
PFBC
IGCC
All the available technologies are based of ‘Rankine Cycle’
It essentially uses ‘Condenser’ which limits the cycle efficiency to ~ 50%
We need to develop a ‘cycle’ which is fundamentally different.
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Abundant Power
The country has plentiful energy sources marked coal superabundance and weak
hydrocarbons…
100
 Coal Reserve 250 billion tons
80
 Gas Reserve 553 bcm
60
 Petroleum Reserve 5.4 billion barrels
40
20
COAL
LIGNITE
GAS
PETROLEUM
0
Coal remains the most important fuel for power industry
Coal is likely to become the source of Synthetic Fuel & Electricity required for Transp. Sector
Coal is expected to become the fulcrum of ‘Hydrogen Economy’
Development of ‘Alternate Power Cycle’ has to be based on Coal being supplemented
by bio mass, water and solar
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Clean Power
Producing clean power with coal, even today, is a challenge
The Challenge
Fuel extraction
island
=85-90%
Combustion
Island
[Boiler]
Power
Island
[Turbine]
=65%
=85%-90%
=95%




Hot Climate:
 Low Condenser Vacuum &
Boiler Eff
 No requirement of District
Heating
Transmission
Distribution
[80%]
Overall <22%!!!
Very High Ash Content: 40% - 50%
High Alfa Quartz Content
High Abrasive Index
Low Heating Value: 2500–3500 Kcal/Kg
Coal
Climate
Tech
nology
I suggest two frontier
technologies this country
can take up in MISSION
mode. They are
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The Solution : The frontier technology - 1, India centric
Migrate from ‘Rankine’ based power to a fundamentally new one (Hybridise Rankine at
back end using ammonia cycle)
Char comb.
Chemical
Energy
[Coal]
Gasification
Island
[Gasifier]
island
Electrical
Energy
[Fuel Cell]
~95%
Cycle Efficiency
[65% - 80%]
~80%
Syn. Gas
Syn. Liquid Hydrocarbon
Coal
Ammonia / Urea / Chemical
Unconverted
Fuel Separator
Bio mass
Steam
Gasifier
Hydrogen
Electricity
Hot Gas Cleanup
Fuel Cell
Gasification Island
Bubbling bed
Absorber
CO2
CCS
Zeolite
Cooling
Combustion Island
MALAE
Cycle,
Low gr.
Q
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The Traditional Power Generation cycle
Thermal
Energy
in Boiler
14000C
Mechanical
Energy in
Turbine
5200C
Chemical
Energy
in Coal
Fuel cell
(Gibbs FE)
Electrical
Energy
in Generator
Governed by 2nd Law of Thermodynamics
Input Energy = 100
Output energy =33
Carnot Engine
(Energy)
How to Increase the Efficiency of this system ?
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Why fuel cells?
• Almost all conventional technologies use combustion and Carnot cycle
• In this, the maximum theoretically achievable efficiency depends on heat source and
sink temperature
• Though higher efficiency up to 83.7 % is possible, actual achievable efficiency is
limited by non-availability of suitable materials for such high temperature
Fuel cells are electrochemical devices that convert the chemical energy of a reaction
directly into electrical energy.
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Frontier technology-2, Solar To Fuel And Electricity
Interfacing biology with physical sciences at nano-scale will be what ultimately will
provide an abundant and perpetual source of fuel and power – perhaps at par with
fusion. Fusion mimics solar while this would mimic nature (photo synthesis)
Electrical
Energy
[Fuel Cell]
•Water
•Bio Mass
Artificial
Photo
Synthesis
•Hydrogen
•Methanol
•Syn Gas
•Electricity
Water / CO2
Bio Mass
Fuel
Bacteria
Gasification
Island
[Boiler]
Solar Photon
Chemical
Energy
[Coal]
Artificial
Photosynthesis
Hydrogen
Methanol
Electricity
Syn Gas
Alt. Fuel
Products
Use
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What is different than already known?
1. Low temperature water (& CO2) splitting – to produce hydrogen or methanol
2. Low temperature conversion of cellulose (bio mass) into synthesis gas –
Substitute for high temperature gasification process
Elements in Solar to Fuel & Electricity
Powered by sunlight, nano
scale inorganic materials
embedded in organic base
convert water, CO2 to
hydrogen, methanol
Polymers made from
customised dendmimrimers
mimic photosynthesis
Using technique of synthetic
biology, yeast can
manufacture fuels from bio
mass
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Way forward:
I suggest following
1.
Set up a 25 Mw (equivalent) FT-1 Mission. About six top
institutions and two R&D savvy industry. Government to mentor
the mission
2.
Set up National Mission on Solar to Fuel Mission (FT-2). Would
require interface with Nano, Synthetic biology and
electrochemistry as backbone. Engg. Science to be introduced
later
At a later stage FT-2 will be dovetailed with FT-1
Time frame, Budget, Institutional mechanisms ???
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While I have suggested two frontier technologies, the
existing technologies seek intervention of good number of
technological solutions. Today we have adequate tools
(scientific), knowledge, operating experience to develop the
intervention technologies.
May I suggest we take up one more new development of solar
through heliostats? What is this 
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Solar Tower
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Solar Tower
• A field of flat mirrors concentrate light on central receivers
• As flat mirrors can have two-axis solar tracking, high collection efficiency
(>80%)
Cont.
• An HTF (molten salts) is heated up (550 Deg C)
supply
• Generate steam in a heat exchanger (535 Deg C)
• Run a steam cycle – Overall efficiency : about 24%
Salt Cycle
cold
storage
hot
storage
steam
generator
290 °C
input from
condenser
565 °C
output to turbine
CONCLUSION
“When you really want something to happen, the whole
universe conspires to help you to achieve your dreams”
…….. The Alchemist
by Paulo Coelho
Photo-Electrochemical Hydrogen
•
Combine Electrolysis an PV technology into a one step process
•
Problems: Chemical photo-corrosion and high cost
V
eH2O + 2 h+
H2
R
H
-
Na2SO4
Photoanode
+
2e-
Cathode
2H+
hv
2H+ + 0.5O2
Photochemical Hydrogen
• Reactions occur at individual molecules suspended the solution
• A Photo-Synthesizer works in conjunction with a relay compound to transfer energy
and generate hydrogen
S+
H2O
H2
Oxidation
Catalyst
0.5 O2
2H+
Sun
hv
Reduction
Catalyst
S
2H+