Clean Coal Technologies
Coal : Fuel of the Past or
Fuel for the Future
Tomasz S. Wiltowski
Advanced Coal and Energy Research Center and
Department of Mechanical Engineering and Energy
Processes
Southern Illinois University
Carbondale, IL 62901
Grand Challenges for Next 50 Years
from Nobel Laureate Richard Smalley (1943-2005)
1. ENERGY
2. WATER
3. FOOD
4. ENVIRONMENT
5. POVERTY
6. TERRORISM & WAR
7. DISEASE
8. EDUCATION
9. DEMOCRACY
10. POPULATION
2004
2050
6.5 Billion People
~ 10 Billion People
Crowded
the United States population on May 15, 2015 was: 315,857,050
the World population on May 15, 2015 was 7,085,613, 221
http://www.census.gov/main/www/popclock.html
China
India
America
Africa
Europe
The Rest
= 1.37B
= 1.17B
= 0.94B
= 0.92B
= 0.82B
= 1.56B
Mumbai, India - Rush Hour
US growth rate 18 births every 4 minutes
World growth rate 615 births every 4 minutes
Our Interest - Sustainable Development
• “development that meets the needs of the
present generation without undermining
the capacity of future generations to meet
their needs.”
Coal’s Sustainability Challenge
• Economic and social criteria make a compelling case for
coal – the issue is environmental performance
• Climate change concerns present a complex challenge for
the continuing use of fossil fuels and coal in particular
Clean Coal Technologies:
- Gasification
- Oxycombustion
- Chemical Looping
- Coal to Liquids
- CO2
Integrated Gasification Combined Cycle (IGCC)
Gasification is essentially partial oxidation under pressure
IGCC + Carbon Capture and Storage
IGCC + CCS + Poly generation
Barriers to IGCC Commercial Deployment
•
•
•
•
Cost → 10-20% penalty for bituminous coal
Traditional PC can meet current environmental standards
IGCC financing costs higher than PC – perceived risk profile
No reward for risk taking – new plants largely being built by
regulated utilities
• Excess capacity in many regions - NGCC overbuild
• IGCC needs more project development than NGCC or PC
– To date no standard IGCC design - this will change with GE entry
• Lack of familiarity with IGCC in the power industry (it is a
chemical plant)
“NOVEL” COAL
COMBUSTION
Combustion Efficiency and
Pollutants Emission
Improving efficiency levels
increases the amount of
energy that can be
extracted from a single
unit of coal. Increases in
the efficiency of electricity
generation are essential in
tackling climate change.
Background
 In most conventional combustion processes, air is used as
the source of oxygen;
 Nitrogen is not necessary for combustion and causes
problems by reacting with oxygen at combustion
temperature;
 A high concentration of nitrogen in the flue gas can make
CO2 capture unattractive;
 With the current push for CO2 sequestration to ease
climate change, it is imperative to develop cost-effective
processes that enable CO2 capture;
 The use of pure oxygen in the combustion process instead
of air eliminates the presence of nitrogen in the flue gas,
but combustion with pure oxygen results in very high
temperatures
Oxycombustion
Coal
Oxycombustion
Chemical Looping Combustion
(CLC)
Chemical looping combustion (CLC) has emerged as
one of the most promising technologies for low-cost
CO2 capture technologies for solid fuels. CLC
provides the possibility of CO2 capture without the
requirement of an air separation unit or an
absorption process.
What is Chemical Looping
Basic concept
What is Chemical Looping and does it work?
Limestone based Chemical Looping Process
Chemical Looping features:

up to 100% CO2 capture efficiency,
 highly concentrated stream of CO2 ready for
sequestration,
 no NOx emissions,
 no costs or energy penalties for gas separation,
 CLC uses well-established boiler technology, which
means that costs can be assessed with great
accuracy, and
Efficiency of Chemical Looping
higher efficiency is because chemical looping systems use
solids to carry the oxygen in and out of the process,
leaving essentially no thermodynamic penalty associated
with either the carbon separation or oxygen production.
CRITICAL PROBLEM WITH SOLID FUEL:
Can the fuel particles and oxygen carrier particles be readily separated?
If not, there is carryover of solid fuel to the oxidation reactor and
emission of CO2 in the air regenerating the carrier particles.
Hence, solids require a modified strategy
FISHER – TROPSCH
Synthesis Of Liquid Fuels
Coal To Transportation
Liquids (CTL)
Coal
Gasification
Fischer-Tropsch
Synfuels: 1-2 barrels of oil per ton of coal
What are the challenges that must be
overcome before coal to liquids becomes
a reality?
1.
2.
3.
4.
Uncertainty regarding crude oil prices-oil at $70,
make a bundle: oil at $40 lose your shirt.
Reducing the cost of conversion process: some
uncertainty remains.
Climate change: coal releases more CO2 than
other fuels. CO2 injection? CO2 conversion?
Usage in engines-who will certify fuels?
CO2 emissions vs fuel type
Coal
lbs per MWh
564
Natural gas
331
NREL technical report NREL/TP-840-400665
CO2 Chemical Utilization
Renewable fuels &
chemicals
Synfuels
CH3OH
CH3OCH3
hn
H2O
H2
HCOOH
RWGS
Syngas
H2/CO
FT
Synfuels
Hydrocarbons
&
alcohols
CO2
Dry Reforming
CH4. CH4, CH3OH, HCOOH
organics
ODH
Chemicals
Light olefins
High-added
Value materials
Organic carbonates
& carboxylates
THANK YOU!