CIBO Emissions Control Con

Bi

o ass ue o t e utu e mass: Fuel 

of 

t

h

e Futu

r

e

?

Presented by Tom Sarkus

2009

09-GASIF215-1 – UAF Coal-Based Region Studies

August 5, 

Rev 1 CIBO
BUZZ Words For Tod

BUZZ Words For Tod

BIOMASS

B

L

E

N

D

S

C

O

-FIRING

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09-GASIF215-2 – UAF Coal-Based Region Studies
Thank You!

Many of the slides and information presented here are cou

Dr. David A. Tillman

and 

Dao N.B. Duong

of

Foster Wheeler North America

Original presentation and papers titled

“Fuel Blending for Bituminous Coal Boilers: Some Fuel E

“Co-Firing – Basic Issues and Concerns”

“Fuel Selection for Cofiring Biomass in Pulverized Coal and 

Fried Boiler”

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09-GASIF215-3 – UAF Coal-Based Region Studies
Reasons for Fuel Blendin

• Supply – Original coal mine worked 

supp y y l securit

y

• Economics 

– Reduce coal costs & 

costs; tax credits

• Environmental

– Use cleaner burn

(low sulfur, low nitrogen, low ash) co

• Regulatory – Thou will do so

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09-GASIF215-4 – UAF Coal-Based Region Studies
Typical Fuel Blends

• Common Current blends

– Bituminous coal/bituminous coal Bituminous coal/bituminous coal– Gob/bituminous coal– Bituminous coal/tire chips– Bituminous coal/petroleum coke– Bituminous coal/Powder River Basin [PRB– PRB l/li it PRB coal/lignite

• Common future blends

– Bitu ous coa /b o ass minous coal/biomass– PRB coal/biomass– Waste coal/biomass

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09-GASIF215-5 – UAF Coal-Based Region Studies
Unique Performance Parameters for 

and Biomass Fuels and Biomass Fuels

Parameter Central

Appalachian

Illinois

Basin

Powder River

Basin

Lignite Wood

Waste

HHV Btu/lb A R HHV, Btu/lb

A.R. 12 114 , 10 334 8 943 7 613 5 028 

(55lb/cf)

10,334

8,943

7,613

5,028

(18lb/cf)

lb/106 Btu of 

Fuel

83 97 112 131 199 

Fe2O3/CaO 3.63 3.04 0.26 0.54 0.03 

lb Cl/mmBtu 0.10 0.29 0.01 0.01 0.03 

Lb(NaO+

KaO/106Btu

0.38 0.28 0.11 0.13 0.49 

Lb S/106Btu 0.88 3.14 0.26 1.10 0.14 

lb H2O/106Btu 5.91 5.79 28.89 35.12 83.53 

lb ash/106Btu 9.51 10.29 5.65 12.05 4.59 

lb fuel N/106Btu 1.11 1.05 0.75 0.77 1.19 

VM/FC Ratio 0.62 0.73 0.84 1.08 6.05 

Cl/S molar ratio 0 12 0 10 0 05 0 01 0 21 

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09-GASIF215-6 – UAF Coal-Based Region Studies

Cl/S molar ratio

0.12

0.10

0.05

0.01

0.21 
Guiding Principle:

Fuels are unique.

Bl di t f Blending 

two or more 

fue

to

gether creates a new 

unique fuel.

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09-GASIF215-7 – UAF Coal-Based Region Studies
Unique Blends of Central Appalachian 

and Wood and Wood

Parameter 0% Wood Co-fired 5% Wood Co-fired

(Heat Input Basis)

10% Wood Co-fired

(Heat Input Basis)

20

(H

Mass % of Wood 0% 11.25% 21.12% 

HHV, Btu/lb 12,114 11,316 10,617 

Base/Acid 0.20 0.22 0.24 

Fe2O3/CaO 3.63 2.43 1.78 

lb Cl/mmBtu 0.10 0.10 0.09 

lb(NaO+ 0.38 0.39 0.39 

KaO/106Btu

lb SO2/106Btu 0.88 0.85 0.81 

lb H2O/106Btu 5.91 9.79 13.67 

lb ash/106Btu 9.51 9.26 9.02 

lb fuel N/106Btu 1.11 1.11 1.11 

VM/FC Ratio 0.62 0.73 0.84 

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09-GASIF215-8 – UAF Coal-Based Region Studies

Cl/S molar ratio 0.12 0.12 0.13 
Second Guiding Princip

Each blend is unique and m

be e al ated on its o n tebe

e

val

uated on its

o

wn te

There are blending princip

however, that can be use

evaluate blending.

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09-GASIF215-9 – UAF Coal-Based Region Studies

evaluate blending.
Locations for Blendin

g

• At an off-site blending facility• In the coal yard (blending here is mea

and controlled blending, not bucket and controlled blending, not bucket

blending)

• In coal pipes or chutes leading from t

to the burners or boiler 

( y

this is ver

y d

• In the boiler

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09-GASIF215-10 – UAF Coal-Based Region Studies
Biomass Handling - The 10 Keys

•Fuel Handling not glamorous, but oh so important

•Keep transport veloc

but oh so important above flame speed of •Keep biomass separate in coal yard•Keep biomass away from coal

above flame speed of 

(120 ft/sec)•When biomass is mo

•Keep biomass away from coal it moving

bunkers and silos. It needs its own silos

•Don’t use coal prep equipment

it moving•Do not mix biomass ttransportation system

•Don t use coal prep equipment

•Particle sizing is imp

for biomass which is fibrous•If firing with pneumatic 

transport recognize biomass

•Particle sizing is imp

biomass does not neefine as coal

transport, recognize biomass

•Firing method is imp

generally equals pluggage 

•Firing method is imp

flame structure within & NOx control

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09-GASIF215-11 – UAF Coal-Based Region Studies
Combustion Impacts:

e.g., Bituminous Coal & PRB Co

• Some blends are well known Some blends are well known

– significant body of experie

significant body of experie

– Significant differences based on bituminous coal (e.g.

Appalachian vs. Illinois Basin)

– M j l t diff i l d i t lf 

M

ajor coal proper

ty differences inclu

de: mois

ture, sulf

nitrogen content, chlorine content, ash content

– Some additional major differences based on: coal reac

reacti it l h h i t ( ti l l F C K N 

ti

vity, coal as

h c

hemis

try 

(particularly 

Fe, 

Ca, 

K, N

• Blends do not behave as the weighted average of the fue

particular, reactivity and ash chemistry are influenced by s

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09-GASIF215-12 – UAF Coal-Based Region Studies
Capacity Impacts of Blends

• Blend impacts on capacity

– Increasing or reducing the effective Btu/lb & Btu/ft

fuel fed to the boiler fuel fed to the boiler

– Increasing or decreasing the volume of gaseous 

combustion products (e.g., from moisture) past the 

capability of the forced draft or induced draft fans capability of the forced draft or induced draft fans

• Blends that can increase capacity

– Bituminous coal & petroleum coke

• Blends that can decrease capacity Blends that can decrease capacity

– Bituminous coal & low rank coals [e.g., high perce

PRB coal]

– Bi i l & i ifi f bi Bituminous coal & significant percentages o

f biom

[>20%]

– In waste coal operation biomass may not increasin

d i th t t

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09-GASIF215-13 – UAF Coal-Based Region Studies

re

ducing the ou

tpu

t
Flame Profiles of Blends

•Some impacts of bituminous coal/biomass blends [10

-20%

•Some impacts of bitum

coal/biomass blends [10 20% coal/PRB blends [

>50% 

biomass]

– More rapid ignition of the 

fuel mass

coal/PRB blends [ 50% 

– More coal in boil– Flame filled boile

More gaseous co

fuel mass

– More gaseous combustion 

products – watch fans

•Impacts of coal/pet coke blends

– More gaseous co

products – can pcapacity limits

•Impacts of coal/pet coke blends

– Less fuel in boiler– Slower combustion– M bi h ore com

bustion as c

har 

oxidation

– Less gaseous combustion 

d t

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09-GASIF215-14 – UAF Coal-Based Region Studies

pro

duc

t

s
Efficiency Impacts

• Blends have differing efficiency impacts; loo

Bt /lb & Bt /ft3 – Btu/lb & Btu/ft f bl d 3 of blend

– Moisture content of blend– Ash content of blend Ash content of blend– Oxygen content of blend– Fixed carbon/volatile matter ratio of blend [ 

ca

unburned carbon]

– If blending biomass in the boiler [separate inj

thi i th i h t it t t d this raises the air heater exit temperature and 

ambient air in boiler; also an efficiency impac

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09-GASIF215-15 – UAF Coal-Based Region Studies
Deposition Considerations

• Some blends increase alkali & alkali earth elements – cau

increased deposition increased deposition

– Low rank coal & biomass blends [particularly blends w

switchgrass, corn stover, or other agricultural crops]

• Some blends can decrease deposition by decreasing ash 

Some blends can decrease deposition by decreasing ash 

dramatically

– Petroleum coke & woody biomass blends with low ash 

fuels

• Some Issues of concern

– Increased quantity of calcium fed to boiler (lb/hr)

– R fl i h i ll i f l k l R

eflective as

h in waterwall section 

from low ran

k coals

– Fe

2

O

3/CaO ratio; interaction between iron oxide (bitum

coal) and calcium oxide (low rank coal or biomass) 

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09-GASIF215-16 – UAF Coal-Based Region Studies
Corrosion Considerations

•Some key considerations

– Chlorine in some

•Some potentially probl

Chlorine in some combinations

bituminous coals (e.g., Illinois Basin, Central 

Appalachian)

combinations

– Chlorine with alk

(particularly in th

of sulfur)

– Alkali metals and earth 

elements in low rank coals 

and biomass

of sulfur)

– Alkali metals with 

vanadium (forma

dt ) and biomass – Vanadium in petroleum 

coke

– Low NO Firing

vana

d

a

tes

)

– Firing method pla

– Low NO in thi

s issue

x Firing

– CFB limestone will absorb 

some of the Chlorine

s ssue

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09-GASIF215-17 – UAF Coal-Based Region Studies
Industry’s view:

That Sounds Great...

...But

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09-GASIF215-18 – UAF Coal-Based Region Studies
Cast of the

"Buck Rog y

ers in the 25th Century" Radio P

Left to Right: Curtis Arnall (wearing gravity-defying inertron), Elain

Melchior, William Shelley, Edgar Stehli (holding cybro-destructAdele Ronson.

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09-GASIF215-19 – UAF Coal-Based Region Studies
Biomass - The 3 Summary Po

• Higher mass fuel flows from very high mass percenta

biomass blend

– 20% biomass > 28% increase fuel flow > decrease in 

value of blend

• 20% Biomass 

– > HHV decreases, fuel flow increases > Volatility incre

flame or heat release moves higher in furnace > Affectransfer > causes unburned carbon

• Slagging & fouling may Increase at/in high temperatu

– As Base/Acid ratio > 0.2 to 0.3 > indicates possible pro

– Na

2O and K

2 > increase over 0.4 > possible slagging c

– Fe

2

O

3/CaO > fluxing ratio > moves into difficult area

20

09-GASIF215-20 – UAF Coal-Based Region Studies
Conclusions - 1

• Blending is becoming increasingly common 

Blending is becoming increasingly common, 

be more so in the future

• Blends will involve more low rank coals, was

& “green” fuels

• Each blending application is unique• Bl d i t b dd d i i 

Blend issues must be addressed recognizing 

subtleties of fuels and the interactions betwecomponents; blends do not behave as the we

average of components

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09-GASIF215-21 – UAF Coal-Based Region Studies
Conclusions - 2

• Blend selection must take into account

– Fuels available [physically, economically; e.g

biomass wood? Is pet coke available?] biomass wood? Is pet coke available?]

– Firing systems employed [CFB, wall-fired PC

PC, cyclone]

– Needs of the station [capacity, efficiency, em– Needs of the utility [green power & RPS, cos

power production power production

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09-GASIF215-22 – UAF Coal-Based Region Studies
Conclusions - 3

• Each blend is unique Each blend is unique

– You must proceed cautiously when co-f

blends with your coal, waste coals & bio

– Remember the 10 Keys Remember the 10 Keys– Remember the 3 Summary Points

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09-GASIF215-23 – UAF Coal-Based Region Studies
NETL Recommendation and Caut

NETL Recommendation and Caut

• For over 13 years, NETL has recommended w

cautionary note the following when co cautionary note the following when co

-firing 

firing 

Coal:

– Biomass or other co-firing materials should b

to a range of 7% to 10 % by weight to reduce eliminate operation problems eliminate operation problems

– The capital cost of the receiving storing & pr

The capital cost of the receiving, storing

& pr

and injection of opportunity fuel like biomass to 10% to the capital cost of a new power pla

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09-GASIF215-24 – UAF Coal-Based Region Studies
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09-GASIF215-25 – UAF Coal-Based Region Studies
Contact

Thomas A. SarkusOffice of Major Demonstrations Office of Major DemonstrationsU.S. Department of EnergyNational Energy Technology Laboratory626 Cochrans Mill RoadP.O. Box 10940 P.O. Box 10940Pittsburgh, PA 15236-0940

Office Phone: 412-386-5981Cell: 412-215-0339E-mail: Thomas.Sarkus@NETL.DOE.GOV

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09-GASIF215-26 – UAF Coal-Based Region Studies
Disclaimer

This presentation was prepared as an account of work sponsored by an th U it d St t G t N ith th U it d St t G t the United States Government. Neither the United States Government agency thereof, nor any of their employees, makes any warranty, expreimplied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information apparatus product or completeness, or usefulness of any information, apparatus, product, or disclosed, or represents that its use would not infringe privately owned rReference therein to any specific commercial product, process, or serviname trademark manufacturer or otherwise does not necessarily consname, trademark, manufacturer, or otherwise does not necessarily consimply its endorsement, recommendation, or favoring by the United StateGovernment or any agency thereof. The views and opinions of authors therein do not necessarily state or reflect those of the United States Govany agency thereof.

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09-GASIF215-27 – UAF Coal-Based Region Studies