The Cost of Mercury Remo

from Coal-Based IGCC Relative to 

M.D. Rutkowski, M.G. Klett, R.C. Maxwe

Gasification Technologies 2

October 27- 30, 2002

San Francisco, California
Acknowledgments

U.S. Department of Energy

National Energy Technology Labo

Eastman Chemical Compan
Background

EPA Announced It Will Regulate Mercury and 

from Coal-Burning Utilities

• Two EPA reports to Congress (199• Mercury is toxic of greatest conce• Coal-fired plants largest source of • 43 tons of mercury per year
Background

Proposed EPA Regulations to Control Merc

from Coal-Burning Utilities

• Regulations to be proposed by Decem• Regulations to be promulgated by De• Utility compliance by December 2007
Mercury Removal from

Conventional Power Plan

Based on 1997 EPA Report to Congre• Activated carbon injection with and 

spray cooling

• Activated carbon bed• 90% removal from stack gas• $1.43/MWh to $3.10/MWh• $17,400/lb Hg to $37,800/lb Hg• Amounts to nearly 10% of COE
The Eastman Chemical Appr

• Eastman has been removing vap

mercury for 20 years

• Activated carbon beds• Located upstream of AGR proce• Bed changeout every 18 to 24 m• 90 to 95% mercury removal• ~20-second gas residence time i
Tennessee Eastman, Kingspo

Gasification 

Area

Gasification 

Area

EASTMAN EASTMAN
Chemicals from Coal – Final P

Acetic Anhydride

Acetic Acid

Acetic Anhydride Coal Coal Acetic Acid Acetic Anhydride Acetic Acid Acetic Anhydride Coal Coal Acetic Acid

EASTMAN EASTMAN
Environmentally Friendly Pr

• Sulfur removal is > 99.9% (with Rec• Eastman has a patented sulfur-free 

process (available for license)

• NOx is not an issue with chemical p

operations

• Eastman has practiced vapor-phas

removal from syngas since initial p

EASTMAN EASTMAN
Eastman Vapor-Phase Mercury Rem

Water

Rod Mills

1300 ton/dayCoal

Slurry

Pump Slag

Scrubber

Oxygen

Ste

Shift Reaction:

CO + H2O CO2 + 

S

PreheatingGasifier

NG

Quench WaterBlowdown, ClarificatiAnd Recycle

Water

Rod Mills

1300 ton/dayCoal

Slurry

Pump Slag

Scrubber

Oxygen

Ste

Shift Reaction:

CO + H2O CO2 + 

S

Ste

Shift Reaction:

CO + H2O CO2 + 

S

Shift Reaction:

CO + H2O CO2 + 

S

PreheatingGasifier

NG

Quench WaterBlowdown, ClarificatiAnd Recycle

EASTMAN EASTMAN
Vapor-Phase Mercury Removal 

and Performance

• Sulfur-impregnated activated carbo• ~30°C and 900-1000 psig dry synga• ~15-20 seconds contact time (based 

packed volume)

• >90-95% mercury removal (based o

International study)

• >12-18 month lifetime of carbon bed

by pressure drop or shift catalyst couts, not mercury breakthrough)

EASTMAN EASTMAN
Mercury Removal Beds

EASTMAN EASTMAN
Mercury Removal Bed

EASTMAN EASTMAN
Activated Carbon to Remove M

from IGCC

• Calgon type HGR granules• Best temperature is 100°F• No moisture condensation• Sulfided carbon• Adsorbs and converts Hg to Hg• Stable compound for landfill or 
Mercury Removal from IG

• Syngas at high pressure• Low volumetric gas flow• Moderate temperatures• Particulate-free• Moderate humidity
Flow Diagram Showing Locatio

for Mercury Removal

Fuel Gas 

Cooling & 

Knockout

Mercury

Removal

MDE

Un

410°F Fuel Gas

Scrubber

COS

Hydrolysis

103°F

Sour

Water

Stripper Texaco 

Gasifier & 

Fuel Gas

Cooling

ASU

Clau

Pla

Tail G

Treatm

Un

Vent Gas Claus Plant 

Oxidant

Coal

Water

Air to 

ASU

450°F

Slag

Sour Water

Water

Recycle to

Gasifier

Claus Plant 

Oxidant

Vent 

Incin

Gasifier 

Oxidant

Fuel Gas 

Cooling & 

Knockout

Mercury

Removal

MDE

Un

410°F Fuel Gas

Scrubber

COS

Hydrolysis

103°F

Sour

Water

Stripper Texaco 

Gasifier & 

Fuel Gas

Cooling

ASU

Clau

Pla

Tail G

Treatm

Un

Vent Gas Claus Plant 

Oxidant

Coal

Water

Air to 

ASU

450°F

Slag

Sour Water

Water

Recycle to

Gasifier

Claus Plant 

Oxidant

Vent 

Incin

Gasifier 

Oxidant
Mercury Removal Process D

• 250 MW net IGCC plant• Texaco radiant cooler gasifier• GE 7FA gas turbine• 80% plant capacity factor• Mercury removal located upstream • 20-second gas residence time• Low humidity gas• 103°F operating temperature
Activated Carbon Bed Des

Carbon replacement rate 17 tons/Initial carbon charge 25 tonCarbon loading, mercury 0.4%Mercury concentration outlet 5 ppbMercury concentration inlet 52 ppbPressure drop through bed 10 psOperating pressure 378 ps

Two vessels, 7.3 

20.2 ft h

Cylindrical bed configuration
Mercury Removal Cost Ba

O&M labor $7,446/yeOther O&M costs $59,242/yPower penalty $36,792/yTotal O&M $320,683/yCarbon @ $6.43/pound $217,203/yCapital recovery @ 15% $125,153/yTotal capital cost $834,350 ($3.25% contingency $101,75Indirects $122,10Installation $203,50Purchased equipment $407,00
Cost of Mercury Remova

Mercury, $/lb $3,412/lbMercury reduction, lb/year 131 lb/yeaTotal $/MWh $0.254/MWTotal $/year $445,836/y
Compared with Conventional Pow

using Carbon Beds

Cost of removal, $/pound $3,412/pound Fraction of COE < 1% Cost of removal, $/MWh $0.254/MWh Relative volumetric gas flow 1.0 Removal location Syngas ahead of AGR 
Sensitivity to Capital Cost F

Sensitivity of Key Parameters on Mercury Removal Cos

$0.000$0.050$0.100$0.150$0.200$0.250$0.300$0.350$0.400

1

 Relative Capital Cost Factor = 0.5, 1.0, 2.0 

 Cost of Mercury Removal, $/MWh
Sensitivity to Carbon Co

Sensitivity of Key Parameters on Mercury Removal Cos

$0.000$0.050$0.100$0.150$0.200$0.250$0.300$0.350$0.400

1

 Relative Carbon Cost Factor = 0.5, 1.0, 2.0 

 Cost of Mercury Removal, $/MWh
Sensitivity to Carbon Life Fa

Sensitivity of Key Parameters on Mercury Removal Cost

$0.000$0.050$0.100$0.150$0.200$0.250$0.300$0.350$0.400$0.450

1

 Carbon Replacement Time (months) = 9, 18, 3

 Cost of Mercury Removal, $/MWh
Amount of Mercury Remo

Sensitivity of Key Parameters on Mercury Removal Cost

$0.000$0.050$0.100$0.150$0.200$0.250$0.300$0.350$0.400$0.450

1

 Amount of Mercury Removal (%) = 90, 99+ 

 Cost of Mercury Removal, $/MWh
Conclusions

• The cost of mercury removal from an IGCC plant is reduced 

carbon bed in the pressurized syngas stream.

• This stream is characterized as having a greatly reduced vo

relative to that of stack gas by a factor of nearly 200 for the 

• The size of equipment, number of beds, and consequent co

than treating for mercury removal in the stack gas of a PC 

• The estimated cost of $0.254 per MWh and $3,412 per poun

IGCC plant is shown to be significantly lower than costs of from PC power plants.

• The capital cost estimate of $3.34 per kW for removal from 

represents less than 0.3 percent of the total IGCC plant cap

• The small increase in cost of electricity of $0.254 per MWh 

mercury removal system represents an increase in the ovefrom the plant of less than 1 percent.