ACPS2008Sydney Convention Centre19-23 Oct 200819-23 Oct 2008

Alternative pathway to low emissions electricity - challenges for coal preparation

Louis WibberleyPrincipal Technologist

www.csiro.auCSIRO Energy Technology

Content

1. Issues with the current approach to low emissions electricity

2. An alternative approach

3 K bli t h l i3. Key enabling technologies

4. Coal specifications and coal preparation challengeschallenges

2

Current approach Clean Coal TechClean Coal Tech

Based on clean coal CCSCCS

d el

ect

technologies to reduce the cost of next generation, clean coal

O2

deliv

ered

g ,plants with CO2 capture and storage

CO

ASC-PCC, IGCC, oxy-pf 2010 2015 2020 2025 2030

Base plant CCS Trans Distrib Delivered

COE $/MWh $40 $45 $10 $25 $120

η(wet cooled) 43% -8% -2% -2% 31%

η(dry cooled) 41% -8% -2% -2% 29%

Delivered electricity from supercritical pf with CCS, 2015

CO2 capture - efficiency challenge for Clean Coal TechnologiesTechnologies

with capturewith capture

70%

80%H

V)

- 50 years

50%

60%

red

(%, H

50 years

30%

40%

cy, d

eliv

er

CCTCCT

10%

20%

Effic

ienc

0%1800 1850 1900 1950 2000 2050

Issues with clean coal technologies

High efficiency can only be achieved through very large plants (large capital steps)

transmission and distribution losses reduce fuel cycle efficiency by up to 4% and increase COE by up to $35/MWhup to 4% and increase COE by up to $35/MWh

Future CCS will have large energy penalty - around 20% of the power from new plant (which produces more CO2)p p ( p 2)

approximately doubles the cost of power production

penalties greater for old plant

Water cooling – increasing issue, CCS increases this

Low overall efficiency increases the amount of CO2 to be y 2stored – requires access to larger reservoirs

higher efficiency plants could delay the need for CCS, and extend th lif f t ithe life of storage reservoirs

Attributes for an alternative pathway

High thermal efficiency at smaller unit capacity

Increased adaptabilitycan adapt to CCS with less impact on efficiency and cost

suitable for dry climates – reduced fresh water/easier to dry cool

development potential - maintaining options, energy security

Increased flexibilityshorter startup time, high efficiency at part load … and in hot weather

Cost competitive and acceptable technology risksmaller units mean economies of scale must be achieved through

lti l itmultiple units

priorities dictate a pathway based on existing (or near term) technologies – at least in the short termg

Higher efficiency the key

Increased efficiency

Less CO2 produced

Less CO2 to be captured

Less extra CO2 from capture

Less CO2 to be stored

Current fuel cycle efficiency for deliveredelectricityelectricity

70

LSD low speed diesel engineMSD med speed diesel engineCCGT combined cycle gas turbine

60

70)

y gGT open cycle gas turbineIGCC integrated gasification

combined cyclePF advanced pf

50

60

cy (%

HH

V

CCGT

LSD

40al e

ffici

enc

PFGT

MSD

IGCC

30

Ther

m

Centralised

201 10 100 1000

DistributedDecentralised

Centralised

1 10 100 1000Unit capacity (MW)

2030 fuel cycle efficiency for deliveredelectricityelectricity

70

DCFC direct carbon fuel cellLSD low speed diesel engineMSD med speed diesel engineCCGT combined cycle gas turbine

60

70H

V) LSD

DCFC GT open cycle gas turbineIGCC integrated gasification

combined cyclePF advanced pf

50

ency

(% H

H

CCGTLSD

MSD

IGCC

40

rmal

effi

cie

PFGT

30Ther

DistributedDecentralised

Centralised

201 10 100 1000

Unit capacity (MW)

Distributed

Step change in thermal efficiency

The most efficient means for converting fuel energy to electricity is via internal combustion heat engines and fuel cells

C l ld hi t i i th l ffi iCoal could achieve a step increase in thermal efficiency using

Direct injection coal engines (DICE)Direct injection coal engines (DICE)

Direct fired gas turbines (DFGT)

Direct carbon fuel cell (DCFC)( )

Over 47% thermal efficiency should be possible with CO2capture now, and over 65% in the future

All require efficient production of ultra clean coals

Proposed alternative technology pathwaypathway

Ultra clean coalsUltra clean coals

DICEDICE

tric

ity Clean Coal Technologies

renewablesrenewables

ed e

lect

DCFCDCFC

deliv

ere

Extreme Coal Technologies

CCSCCS

CO

2fo

r C

2010 2015 2020 2025 2030

Paradigm shift

Dirty Clean

Pf fuel cycleRaw coal Electricity

IGCC fuel cycleRaw coal Electricity

Direct fired coal fuel cycleRaw coal Electricity

12Advanced coal processing –physical and chemical

Component technology #1

Ultra Clean Coal Water Fuels

Coal water fuels

Approx 8 Mtpa globally

Typically 30% water

Highly stable, with 12-24 th t ibl imonths storage possible in

unstirred tanks

Bingham viscosity - pasteBingham viscosity - paste when stationary, but thins rapidly with shear

Readily pumpable

For DICE would be micronised20 d dil t d t 45 t%-20µm, and diluted to ~45 wt%

solids before injection

Component technology #2

Adaptation of the low speed p pdiesel engine

Direct injection coal engine

Thermal efficiency of 54% HHV achievable at 100MW l b l d i i100MW scale by low speed marine engines

Coal should be able to achieve a fuel cycle efficiency of 50% (sent out basis)efficiency of 50% (sent out basis)

Coal has been used in diesel engines, mostly by injecting as a coal-water slurryy y j g y

water has negligible effect on thermal efficiency

technical issues of injection and wear mostly addressed in DOE studies (1978-94)

Highly flexible and adaptableeasily cooled, rapid start, waste heat sufficient to energise CO2 capture

UCC Energy undertaking small scaleUCC Energy undertaking small scale demonstration of UCC under APP program

Large diesel engine

Coal engine status

USDOE programs developed “acceptable” technologies for fuel handling, injection and engine management

Although USDOE programs of 1970-80s very successful, no i l ti d t kcommercial operation was undertaken

development terminated due to persistently low oil price

N d f l d t ti d i i lNeed for larger demonstration under semi-commercial conditions remains

large 2-stroke engines most suitable (30-97 MW)large 2 stroke engines most suitable (30 97 MW)

strong interest by large engine manufacturers to participate

Uncertain coal specifications for modern large enginesUncertain coal specifications for modern large enginesadapted from HFO or designed specially for coal

Uncertainty around engine designs to better optimise useUncertainty around engine designs to better optimise use of ultra clean coal water fuels

What has changed from 1980s?

1. Mounting pressure for HFO replacement … not just for diesel

2. New drivers mean willing to pay more for thermal ffi i ( d l t ti fl ibilit t )efficiency (and lower water consumption, flexibility etc)

3. Advances in physical and chemical cleaning of coal (and more to come)(and more to come)

4. Advances in ultra fine milling – lower energy and cost

5 New materials for engine components ceramics and5. New materials for engine components – ceramics and coatings

6. Increase in available engine size and efficiency6. Increase in available engine size and efficiency

7. Advances in engine control - all electronic systems give improved efficiency and emissions

Component technology #3

High penetration renewablesg p

High penetration renewables

Wind and solar have issues with short & long term energy storage

short term storage doubles cost, long term is impracticalterm is impractical

Inefficient use of biomass fuels in small dedicated plants

Spinning reserve Backup

p

Extreme Coal Technologies could be used to underpin the

fEfficientuse of Grid

development of renewables

DICE could provide efficient and cost effective spinning reserve

use of biofuels support

cost effective spinning reserve, long term backup, a means to efficiently use local biomass fuels ( h l ) d id t(char, algae) and grid support

Component technology #4

Direct carbon fuel cells

Direct carbon fuel cell

High thermal efficiencyg yover 90% (theoretical)

Extremely high efficiencyExtremely high efficiency achieved with UCC coal sample

Many configurations proposedsolid and liquid electrolytes

Currently at the laboratory and small pilot scale

Expect to be available for commercial generation by 2030commercial generation by 2030

giving >65% efficiency with CCS

One of many configurations

Component technology #5

CO2 capture and storage2 p g

CO2 capture and storage

Even at 100% efficiency, coal can only match gas

some CCS will eventually be required for fossil fuelled stationary power generationfuelled stationary power generation

R&D required to optimise capture from DICE and DCFC

DICE exhaust between pf and GTcapture using waste heat integrationp g g

DCFC flue gas similar to oxy-pf“capture” would not be requiredcapture would not be required

Potential to reduce energy penalty to 35% of that for Clean Coal Technologies

CO2 capture – less impact for Xtreme Coal TechnologiesTechnologies

with capturewith capture

70%

80%H

V)DCFCDCFC

50%

60%

red

(%, H

DICEDICE

30%

40%

cy, d

eliv

er

CCTCCT

10%

20%

Effic

ienc

0%1800 1850 1900 1950 2000 2050

CSIRO Extreme Coal Program – heat engine

System benefitsSystem benefits

additivesunderpinning renewables

Advanced coal processing

additivesrenewables

physical Coal-engine interactions

integrated emissions chemical

Atomisation/combustion

VM/char/ash/additives

control chemical /combustion additives

Advanced coal processing

Optimising between 5

Hypothetical cost curves

physical and chemical cleaning

N l h t4

5

(0.5

% a

sh)

OverallNovel approaches to physical separation

moisture and fines in

3

ost

$/G

J (

Stage 2 - Chemicalmoisture and fines in product are OK

magnetite carry over and ceramic mill media

1

2

oces

sing

co

ceramic mill media debris may not be OK

CSIRO program to 0

0 2 4 6 8 10 12Pr

o Stage 1 - Physical

p gdevelop super clean coals or “SuperCoal” using physical cleaning

Ash content after physical cleaning or before chemical cleaning (%, db)

using physical cleaning

Coal-engine interactions

Behaviour of coal under simulated engine conditions atomisation and combustion at 12-20Mpa and 1400-1800°C

Volatiles enhancementfunction of maceral content, grind, injection conditions, additives

Char morphology and burnoutlacy, cenosphere, coherent, burnout kinetics, effect on flyash

Behaviour and fate of residual mineral matterinfluence of occurrence in different coal macerals, cylinder conditions, interaction with trace inorganics and other fuels

Morphology of flyashMorphology of flyashsize distribution, particle shape, hardness

Effect of micronising mill type and grindEffect of micronising – mill type and grind

Nominal coal specifications for 1-5MW engines (larger engines may be more relaxed)(larger engines may be more relaxed)

Property Ideal Comments

Ash <1% Uncertain effects, up to 3% was deemedacceptable, likely to be strongly affected by mineral occurrence, char burnout, atomisation, engine materials and designengine materials and design

VM >25% Wide range used, uncertain VM enhancement factors

Fl h S h i l W lik l t b hi h t f h d lFlyash Spherical Wear likely to be highest for hard angular particles in 10 – 30µm range

Grind D90 <20µm Probably OK to 50µm for high VM coal

Sulphur As for pf Above 0.5% FGD likely

Alkalis No data Turbo charger and waste heat recovery temps <450ºC, spheroidisation of flyashp y

AFT No data Slagging unlikely due to low metal temps and cycling

Extrapolations from USDOE work over 1978-94

Final comments

UCCsUCCs1. There is an alternative pathway for low emissionsUCCsUCCs

DICEDICE

coal-based electricity using direct fired internal combustion engines initially, and then carbon fuel cells

cost effectively underpins a high penetration of renewablesDICEDICE

renewablesrenewables

cost effectively underpins a high penetration of renewables

50% reduction in CO2 intensity possible without capture

2 Further reduction in CO intensity could be achievedDCFCDCFC

2. Further reduction in CO2 intensity could be achieved with a marked reduction in storage required over that for current clean coal technologies

CCSCCS3. Requires efficient production of ultra clean coals

4. Advanced coal preparation is required to minimise fuel cost and to maximise cycle greenhouse gas benefits

2010 2015 2020 2025 2030

Energy TechnologyName Louis WibberleyTitle Principal TechnologistPhone 61 2 4960 6050Email Louis.Wibberley@csiro.auWeb www csiro au/detWeb www.csiro.au/det

Thank You

Phone 1300 363 40061 3 9545 2176+61 3 9545 2176

Email enquiries@csiro.auWeb www.csiro.au

www.csiro.au