1

Black Liquor Gasification Combined Cycles: Mill Integration Issues, Performance and

Emissions Estimates

Stefano Consonni*§, Eric D. Larson§, Ryan E. Katofsky‡

* Politecnico di Milano § Princeton University ‡ Navigant Consulting

Colloquium on Black Liquor Combustion and GasificationSalt Lake City, May 13-16, 2003

Pulp & Paper industry has the infrastructure, the experience and the expertise to handle large quantities of woody biomassGasification can very substantially increase the efficiency of energy recovery from biomass → P&P industry can become net exporter of electricity and/or bio-fuelsIn the next decade, the industry will face the need to replace or refurbish a significant fraction of its recovery boiler fleetMost of the US P&P capacity is concentrated in the South-EastDOE, a number of paper companies through AFPA and two utilities (Southern Company and TVA) have sponsored a case study to assess the potential of Black Liquor Gasification Combined Cycles (BLGCC) in term of energy, environmental and economic benefits

Background

2

Biomass is a small part of the US primary energy mix (3.2%), butis second only to hydropower among renewable energy sources

1998 Total US Primary Energy Consumption – All Sectors and Sources

Coal and Coke23.0%

Natural Gas23.2%

Petroleum38.8%

Biomass3.2%

Hydro3.8%

Other7.5%

Nuclear7.6%

Wind0.0%

Solar0.1%

Geothermal0.4%

Primary Energy in the US

In the US, 75% of non-hydro renewable power generation is biomass-based, accounting for 1.5% of total power generation.

1. Data reported includes peat, municipal solid waste, landfill gas and tires.Source: DOE/EIA Renewable Energy Annual 1999 (DOE/EIA-0603(99)) and DOE/EIA Electric Power Annual 1998.

1998 US Electricity Generation by Fuel Type

Coal51.6%

Petroleum3.5%

Natural Gas15.3%

Nuclear18.5%

Wind0.1%

Solar0.0%

Geothermal0.4%

Biomass1.5%

Hydro8.9%

OtherRenew.

2.1%

Other0.1%

Total = 3,634 billion kWh

Total = 74.7 billion kWh(Biomass1 = 55.8 billion kWh)

Non-Hydro Renewables

Mostly in thepulp & paperindustry.

Electricity Production in the US

3

Recovery Boilers built in North America by year

0

2

4

6

8

10

12

14

16

18

20

1938

1947

1949

1951

1953

1955

1957

1959

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

START-UPS RE-BUILDS

Pulp & Paper in the US South

Southeast ~ 80 Kraft mills

United States ~ 120 Mills

Kraft mills served by SoCoMajor natural gas pipelines

Sources:

Pulp mills: 2001 Lockwood-Post’s Directory of the Pulp, Paper and Allied Trades.

Major gas pipelines: Penwell Mapsearch. (LA, MO, OK TX, TN, VA pipelines are not shown)

4

Pulp & Paper in the US SouthEstimates of International Institute for Environment and Development, 1996

High-Temperature (smelt phase), directly heatedMedium-Temperature (solid phase) directly heatedLow-Temperature (solid phase) indirectly heated

Black Liquor Gasification

5

High-temperature, directly-heated Gasifier

Black liquor is injected at the top of a pressurized (or atmospheric) vessel together with oxygen (or air)Mixture flows downdraft and by reacting ~adiabatically it reaches ~1000°C. Then the gas+smelt flow enters a lower chamber where it is quenched with re-circulated waterSmelt falls in water at the bottom of the quench chamber, thereby generating green liquorRaw gas at ~220°C (temperature depends on pressure) exits laterally toward an MP boiler

High-temperature, directly-heated Gasifieroxygen-blown design with sulfur removal unit

6

Black liquor and air are fed to a fluidized bed maintained below the smelting temperature (~700°C)Raw gas exits from the top of the reactor while solid phase is extracted at the bottom of the bedMild pressurization (~2 bar)

Medium-temperature, directly-heated Gasifierair-blown design

Medium-temperature, directly-heated Gasifierair-blown design

7

Low-temperature, indirectly-heated Gasifier

Heat required to reach gasification temperature is provided by an external heat source: pulse combustor fed with product gasRather than partial combustion, gasifier carries out a steam reforming reaction (quite endothermic) which generates an hydrogen-rich syngasReforming takes places in a bed fluidized with steam (if needed,also with recycle gas) and maintained below the smelting temperature by adjusting the heat provided by the external heat sourceProduct gas exits from the top of the reactor while solid phase is extracted at the bottom of the bed

Direct vs indirectly-heated Gasifier

8

Indirectly-heated Gasifier

Sulfur recovery. S capture from syngas requires:absorption system ( → steam consumption)Claus furnace + SCOT unit ( → steam cons/generation)

Increase of lime kiln loadHigher complexity and tighter integration of steam cycle among:

gasificationsyngas clean-up → chemicals recovery, remove alkali and tarpower islandmill

Reliability of integrated system

Integration issues

9

Hypothetical mill defined to assess the potential benefits of BLG:integrated pulp and uncoated freesheet paper mill1725 machine-dry metric tons paper/daynominal 6 MM lbs/day dry solids 65% hardwood/35% softwoodelectricity consumption 1500 kWh/mt papersteam consumption 10.6 GJ/mt of paper (~10% decrease with respect to current US best practice)

Gasification comes together with polysulfide pulping → yield increases by 3.25 percentage points → for the same paper production, Black Liquor Solids (BLS) flow decreases to 5.42 MM lb/dayTwo gasification technologies: High-T, oxygen-blown and Low-T, indirectly-heat reformerTwo sizes: “Mill Scale” and “Utility-Scale”Hog fuel still used in existing power boilers (no biomass gasification)

Case Study

Current Black Liquor Capacity in the US Pulp Industry

0

2

4

6

8

10

12

Individual Mills

Bla

ck L

iquo

r Cap

acity

MM

bls

/day

(app

roxi

mat

e)

0%

20%

40%

60%

80%

100%

120%%

of t

otal

cap

acity

> MM lbs/day bls % of total USA capacity 4.0 65% 4.5 59% 5.0 53% 5.5 41% 6.0 32% 6.5 28% 7.0 26%

10

Model Power output

Heat RateBtu/kWh kJ/kWh

GE Heavy-duty gas turbinesGas Turbine

GE Frame 6 FA for Mill Scale

GE Frame 7 FA for Utility Scale

When running on syngas, let pressure ratio increase up to 5%, then reduce air flow

Technological Competiton

Compare performances (and costs) of gasification-based systems with

“conventional” Tomlinson recovery boilerHigh Efficiency Recovery Boilers (HERB)

In both cases, extra-hog fuel made available by decrease in mill steam consumption is burnt in existing power boilers to generate extra-steamSteam turbine includes a condensing section to take maximum advantage of the extra-steam

11

Assumptions: production and yield

Gasification

conventnl80% BLS

HERB85% BLS

polysulph.80% BLS

Product flow (paper) machine dry mtons/dayUnbleached pulp rate bd short tons/day

Wood to process (91% of total) 3,208Hog fuel (9% of total) 317

3,525bd kg/day 3,197,860

pine 48.75%hardwood 49.75%

Solids concentration in BL % mass 80 85 80BLS flow lbBLS per day 6,000,000 6,000,000 5,419,646

kJ per kg of BLS 13,892 13,892 13,874Btu per lb of BLS 5,974 5,974 5,966

Composition of BLS C % mass 33.46% 33.46% 32.97% H % mass 3.75% 3.75% 3.70% O % mass 37.35% 37.35% 36.88% S % mass 4.10% 4.10% 4.27% Na % mass 19.27% 19.27% 20.03% K % mass 1.86% 1.86% 1.93% Ashes/Clorides % mass 0.21% 0.21% 0.22%

65% HW, 35% SWWood mix

45.5%46.5%

Parameter unitTomlinson

1,7251,580

Yield

bd short tons/day

Total wood used 3,423,848

3,434340

3,774

HHV of BLS

Steam and electricity consumption

Gasification

conventnl80% BLS

HERB85% BLS

polysulph.80% BLS

lb per st of paper

LP (55 psig) steam to pulp mill 1.00 0.99 1.112.15 2.13 2.25

MJ / mt of paper 7,149 7,100 6,774LP steam from Sulfur Recovery Unit kg/kg of H2S captured 0.0 0.0 1.80IP (80 psig) steam to SRU kg/kg of H2S captured 0.0 0.0 10.00

kg / kg BLS 1.12 1.15 1.16MJ / mt of paper 3,469 3,581 3,247

MP steam from Sulfur Recovery Unit kg/kg of H2S captured 0.0 0.0 3.30kWh / mt of paper 1,500 1,500

kW 107,836 107,836

1.14

Tomlinson

LP (55 psig) steam to paper machine 3600

kg per kg of BLS

LP steam to pulp+paper mill

MP steam to pulp mill

varies withgasificationtechnology

Parameter unit

Electricity consumption

12

Base HERB Low-T High-Tmedium

High-Tlarge

Wood used bone dry kg/s 39.63 39.63 37.01 37.01 37.01DS flow kg/s 31.50 31.50 28.45 28.45 28.45T of black liquor °C 115 115 115 115 115Gasif. Heat loss to environment % of BL HHV - - 1.0 0.5 0.5Heat to cooling screens % of BL HHV - - - 2.0 2.0Carbon conversion % - - 98.5 99.9 99.9Methane in raw syngas % vol in dry raw gas - - 2.8 1.5 1.5T solids/green liquor from gasifie °C - - 250 120 120Tars in raw syngas of input C as phenol - - 1.50 - -T pulse combustor flue gases °C - - 662 - -O2 pulse combustor flue gases % vol wet - - 2.5 - -Fluidization steam kg/kgDS - - 0.25 - -Purge steam kg/kgDS - - 0.01 - -CO2 captured by S-removal CO2/H2S, molar - - 2.00 2.00 2.00T pre-heated air recovery boiler °C 165 220 - - -T flue gases recovery boiler °C 170 130 - - -O2 in flue gases, wet basis % 2.0 1.0 - - -HP steam pressure psig (bar_abs) 1250 (87.2) 1500 (104.5) 1870 (130) 1870 (130) 1870 (130)HP steam temperature °C 480 520 540 540 565Blowdown % of flow to HP ST 1.4 1.3 1.0 1.4 1.2

bar 30.0 25.0 - - -% of RB HP steam 5.1 1.9 - - -

kg/s 7.12 7.12 10.0 10.0 6.7MW LHV 71.2 71.2 100.0 100.0 66.6

psig (bar_abs) 1250 (87.2) 1250 (87.2) 1250 (87.2) 1250 (87.2) 1250 (87.2)°C 480 480 480 480 480

T pre-heated air hog fuel boiler °C 145 145 145 145 145T flue gases hog fuel boiler °C 230 230 230 230 230O2 in flue gases % wet 4.0 4.0 4.0 4.0 4.0

MJ / mt of lime 7.7 7.7 7.7 7.7 7.7MJ / mt DS 1.14 1.14 1.77 1.49 1.49

GasificationTomlinson

Sootblowing steam

Hog fuel boiler HP steam

Kiln consumption

Bark input (50% moisture)

Gasifier andPower Plant

Code developed at Politecnico di Milano and Princeton to predict the performances of power cycles, including:

chemical reactions ( → gasification, steam reforming)heat/mass transfer ( → saturation)some distillation process ( → cryogenic Air Separation)

Model accounts in detail for most relevant factors affecting cycle performance:

scalegas turbine coolingturbomachinery similarity parameterschemical conversion efficiencies

Accuracy of performance estimates has been verified for a number of state-of-the-art technologies

Heat and Mass Balances

13

Base Tomlison Case

Temp., °CPres., barFlow, kg/s

Gross electricity out = 71.99 MWe

Net electriciy out = 64.25 MWeMill steam = 212.06 MWth

Power boiler bark (HHV) = 71.2 MWth

Nat. gas (HHV) = 0Black liquor (HHV) = 437.59 MWth

return from mill + makeup(110°C)

ash

Biomass boiler

Gascleanup

air

to stack

47578.522.30

Air

heat

er

1471.0028.78

201.017.12

201.0128.78

1451.0135.91

black liquor(80% ds)

return frommill + makeup (110°C)

Tomlinsonboiler

smelt

air

LP Air Heater

soot-blowing steam

~Steam turbine71.99 MWe

1651.00134.38

201.01

134.38

34330.05.25

HP steam from power boiler

1504.80

67.03

24613.0

33.23

1504.86.38

Flue gasclean-up

To stack

Drum(87.2 bar)

blowdown

1154.00

39.37

30187.21.73

1700.97

164.74

47578.5103.26

MP AirHeater

hog fuel(50% moisture)

Deaerator (4.8 bar)

Deaerator(4.8 bar)

24613.02.68

8501.01

14.26

1201.01

134.38

480°C

de-SH

blwdwn flash

LP fw heater

1081.333.16

480°C

feedwater to power boiler

4.8-barsteamto mill

1504.80

67.60

13-barsteamto mill

19213.0

35.15

Condenser(30.88 MWth)

400.07414.21

High Efficiency Recovery Boiler (HERB)

To stack

Temp., °CPres., barFlow, kg/s

Gross electricity out = 96.47 MWe

Net electricity out = 88.62 MWeMill steam = 213.30 MWth

Power boiler bark (HHV) = 71.2 MWth

Nat. gas (HHV) = 0Black liquor (HHV) = 437.591 MWth

black liquor(85% ds)

13-barsteamto mill

from LP fw heater + make-up

Tomlinsonboiler

smelt

air

LP Air Heater

steam for soot-blowingand MP+ air heater

~96.47 MWe

1651.01

125.7820

1.01125.78

32925.05.62

1504.85.67

Flue gasclean-up

Drum(103.5 bar)

blowdown

1154.00

37.06

313103.51.73

1700.97

151.12

51593.1

134.48

MP AirHeater

Deaerator (4.8 bar)

32925.03.10

1300.97

151.12

HP fwheater

2201.00

125.78

MP+ AirHeater

32925.02.52

1201.02

125.78

8501.01

14.22

32925.0

17.58

25213.02.76

25213.0

34.08

19213.0

36.29

1524.8

67.13

1524.8

66.53

1524.8

7.25

1404.8

105.52

4.8-barsteamto mill

520°C

blowdown flash

de-SH

400.07422.97

feedwater to economizer

LP fw heater

Condenser(35.97 MWth)

steam from power boiler(Pev=87.22 bar, Tsh= 480°C,

hog fuel = 7.12 kg/s)

47578.5

22.30 930.806.35

Steam turbine

14

High-T Gasifier, Mill Scale

19513.02.25

Temp., °CPres., barFlow, kg/s

Gross electricity out = 135.14 MWe

Net electricity out = 115.29 MWeMill steam = 200.17 MWth

Power boiler bark (HHV) = 100.0 MWth

Nat. gas (HHV) = 14.32 MWth

Black liquor (HHV) = 391.05 MWth

535117

48.97

19513.00.36

13214.00.36

47578.5

31.27

18538.0149.23

13234.3

19.44

1524.80

64.05

25113.0

10.50

1431.01

217.92

18232.0

31.30

4032.4

21.80

11535.0

35.57

~Steam turbine

Gasifier

green liquor

waterheater

Black liquor(80% ds)

Selexol system

clean syngas

Quenchcooler

from mill + from saturator +

make-up

MP steam

LP steam

to stack

12233.6

25.59

rawgas

1000°C35 bar

condensate

48.16MWe

11240.0

149.23

13832.0120.72

steam from power boiler(Pev=87.22 bar, Tsh= 480°C,

hog fuel = 10.00 kg/s)

4032.9

24.24

trimcooler

MP steam to mill

19213.0

32.90

humidified syngas

201.01

38.81

14535.09.46

Oxygenplant

vent

air

251.05

29.36

- 13.69MWe

from saturator

18538.0130.20

19513.019.37

12242.0

33.74

13814.00.79

21735.0

59.32

ST leakage1504.800.64

20034.3

59.32boiler

6261.05216.13

135816.1183.06

43116.6

153.33

201.01

186.37

~Gas turbine

air

86.98MWe

95% O2

Saturator

H2S + CO2

Claus + SCOTplant

to m

ill

1534.80

62.28

1406.0

6.83

to deaerator

1514.800.48

from blowdownflash tank

condensate

105*1.2*

2.45*

19513.0

19.37

HRSGPev=130 bar, Tsh= 540°C

(blow-down 1.14 kg/s from HP drum not shown)

reboiler

strip

perab

sorb

er

18232.01.55

18232.0

29.73

IP steam to sulfur recovery

1816.506.83

1524.801.23

13814.00.06

de-SH

natural gas

2030.00.26

Duct burner

7121.05

217.92

1125.042.65

to gasif. island and power boiler

make-up

make-uptank

Remove alkali

High-T Gasifier, Utility Scale

19513.02.25

560117.070.72

47578.5

20.85

1441.01

450.69

Gasifier

green liquor

waterheater

Black liquor(80% ds)

Selexol system

clean syngas

Quenchcooler

condensate + make-up

MP steam

LP steam

to stack

rawgas

1000°C35 bar

condensate

71.54 MWe

Temp., °CPres., barFlow, kg/s

trimcooler

MP steam to mill

natural gas

20354.85 humidified syngas

Oxygenplant

vent

air

- 13.69MWe

condensatefrom mill

Gross electricity out = 247.4 MWe

Net electricity out = 226.4 MWeMill steam = 200.2 MWth

Power boiler bark (HHV) = 66.6 MWth

Nat. gas (HHV) = 263.0 MWth

Black liquor (HHV) = 391.1 MWth

6171.04

450.69

135915.6384.40

42016.0

348.26

201.01

414.56

~Gas turbine

air

175.84MWe

95% O2

Saturator

H2S + CO2

Claus + SCOTplant

1856.506.83

to deaerator

~Steam turbine

Condenser(46.07 MWth)

400.07421.56

20013.09.39

from blowdownflash tank

201.01

38.81

14535.09.46

251.05

29.36

19513.00.36

13813.00.36

11535.0

35.57

12542.0

33.74

21735.0

59.47

13434.3

19.29

11340

149.80

19513.019.51

20034.3

59.47

4032.4

21.80

12533.6

25.74

4032.9

24.24

condensate

18538.0149.80

1406.0

6.83

105*1.2*2.45

18232.0

31.30

13932.0121.15

18538.0130.65

1135.052.87

13914.00.25

1524.80

64.05

19213.0

32.90

1514.800.48

(blow-down 1.14 kg/s from HP drum not shown)

reboiler

strip

perab

sorb

er

1624.80

61.69

IP steam to SRU

boiler

HRSGPev=130/13 bar, Tsh= 565/200°C

steam from power boiler(Pev=87.22 bar, Tsh= 480°C,

hog fuel = 6.66 kg/s)

1524.8

1.23

to gasif. island and power boiler

de-SH

de-SH

13914.00.66

LP steam to mill

MP steam to mill264

13.01.50

make-up

make-uptank

15

Low-T Gasifier, Mill Scale

H2S + CO2

Gasifier

600°C2.7 bar

3461.50

28.45201.0139.12

45022.54

7.48

1111.01

260.18

136015.76179.91

42716.23

167.98

201.01

200.51

19571.38

45.47

6631.30

45.47

air

~

Gas turbineair

to stack

535117.082.66

clean syngas

76.91MWe

Black liquor(80% ds)

solid

s

syngasheater

syngas - 6.34 kg/s

gasification steam

6001.53

28.45

raw syngasHP boiler

2501.01

14.25

Temp., °CPres., barFlow, kg/s

LP boiler

1504.800.89

~Steam Turbine

LP steam to mill

MP steam to mill

65.10MWe

ST leakage

19213.0

32.91

6001.05

257.91

6131.05212.44

Gross electricity out = 147.0 MWe

Net electricity out = 120.4 MWeMill steam = 200.2 MWth

Power boiler fuel (HHV) = 100.0 MWth

Nat. gas (HHV) = 60.9 MWth

Black liquor (HHV) = 391.1 MWth

syngasexpander

5.00MWe

~

fan

47578.5029.56

M

water

(blow-down 1.14 kg/s from HP drum )

combustor cooling

1786.5012.15

from blowdown

905.062.54

purge steam

Scrubber

Claus + SCOTplant

18.73MWe

return from mill + make-up

1524.802.49

1524.801.64

19513.03.01

9013.01.48

excess syngasto duct burner

1525.000.48

904.800.85

de-SH

de-SH

1504.80

64.05

return frommill + make-up

from SRU

1406.00

12.15

904.82.49

401.011.38

condensateto deaerator

401.4125.24

4023.2023.86

MP water9013.03.17

2501.47

28.45

19513.03.17

5404.507.11

40.023.0

11.93

5351.2845.47

1592.007.48

pulsecombustor

331130

14.34

330130.015.38

331130.015.35

33013014.34

4022.6219.41

105*1.2*4.35

11535.035.57

1582.001.14

1524.8058.58

1524.804.13

24713.0

25.25

HRSG - Pev=130 bar, Tsh= 540°C

331130

1.03

steam from power boiler(Pev=87.22 bar, Tsh= 480°C,

hog fuel = 10.0 kg/s)

1524.807.11

2040.01.12

nat. gas

8211.04

260.18

excesssyngas

Duct burner

water + tar

1582.001.14 383

40.36.93

to HP fw heaters

1524.801.32

to deaerator

Remove tar and alkali

Results: gas turbine and aux. fuel input

Low-T High-Tmedium

High-Tlarge

Air flow to GT kg/s 200.5 186.4 414.6syngas flow to GT kg/s 11.9 29.7 31.3total fuel flow to GT kg/s 11.9 29.7 36.2 Ar % mol 0.00 0.66 0.66 CH4 % mol 3.49 1.44 1.44 CO % mol 23.74 26.09 26.09 CO2 % mol 10.50 11.27 11.27 COS % mol 0.01 0.05 0.05 H2 % mol 61.91 27.51 27.51 H2O % mol 0.34 32.73 32.73 N2 % mol 0.00 0.24 0.24 Total % mol 100.00 100.00 100.00HHV syngas MJ/kg 20.95 9.32 9.32Syngas power to GT kW HHV 249,664 277,024 291,634Syngas to pulse combustor kW HHV 132,791 - -Syngas to duct burner kW HHV 23,794 14,443 -Natural gas flow to GT kW HHV 0 0 263,064Natural gas to duct burner kW HHV 60,857 14,319 0Hog fuel to power boilers kW HHV 100,000 100,000 66,622Res fuel oil to lime kiln kW HHV 50,447 42,311 42,311

Gasification

16

Results: power production and efficiency

Base HERB Low-T High-Tmedium

High-Tlarge

GT gross power output kWel - - 76,910 86,980 175,840ST gross power output kWel 71,990 96,472 65,109 48,163 71,536Syngas expander power ouptut kWel - - 5,004 - -TOTAL GROSS PRODUCTION kWel 71,990 96,472 147,023 135,143 247,376ASU power consumption kWel - - - 13,690 13,690Syngas compressor power cons. kWel - - 18,712 - -Aux. for steam cycle/HRSG kWel - - 1,915 1,194 2,574Aux. for Tomlinson/gasifier island kWel 6,690 6,804 2,667 2,667 2,667Aux. for Sulfur Recovery kWel - - 2,063 1,058 1,058Aux. for steam cycle/power boiler kWel 1,050 1,050 1,244 1,244 1,016TOTAL UTILITIES kWel 7,740 7,854 26,600 19,853 21,005NET electric power output kWel 64,250 88,618 120,422 115,290 226,371Mill electricity consumption kWel 100,096 100,096 100,096 100,096 100,096Power exportable to grid kWel -35,846 -11,477 20,327 15,194 126,276

Total nat gas flow kW, HHV - - 60,857 14,319 262,956Hog fuel input kW, HHV 71,189 71,189 100,000 100,000 66,622Res fuel oil to lime kiln kW HHV 36,032 36,032 50,447 42,311 42,311Margnal efficiencywith respect to Base % - infinite 51.7 94.6 60.2

Tomlinson Gasification

Variations with respect to Base Tomlinson

HERB Low T High Tmedium

0255075

100125150175200225250275300

Extra

Con

sum

ptio

n / G

ener

atio

n, M

W H

HV Extra ElectricityNatural Gas ImportHog Fuel ImportExtra Kiln Fuel

High Tlarge

51.7% 94.6%

60.2%

marginalefficiency

∞

17

Results: emissions

Base HERBLow T Mill

ScaleHigh T

Mill ScaleHigh T Large

CO2 84,038 84,038 213,039 130,704 503,243 SO2 199 199 120 123 95 NOx 2,472 2,472 2,819 2,439 2,648 CO 1,096 1,096 1,023 925 770 VOC 90 90 32 28 29 PM 326 326 139 104 103

Total Point Source Combustion Emissionsmetric tons per year

Tomlinson Cases BLGCC Cases

Base HERBLow T Mill

ScaleHigh T

Mill ScaleHigh T Large

CO2 - 121,727 280,600 254,964 809,855 SO2 - 445 1,026 932 2,962 NOx - 181 416 378 1,201 CO - 18 41 38 120 VOC - 2 5 5 15 PM - 13 30 27 87

Grid Power Emissions Offsets Relative to "Base"metric tons per year

Tomlinson Cases BLGCC Cases

Results: net emissions for 6 MM lb/d Mill

Base HERBLow T Mill

ScaleHigh T Mill

ScaleHigh T Large

CO2 84,038 (37,689) (67,561) (124,260) (306,611) SO2 199 (246) (907) (810) (2,867) NOx 2,472 2,291 2,403 2,061 1,447 CO 1,096 1,078 982 887 650 VOC 90 87 27 23 13 PM 326 313 109 77 17

Net Emissions of each optionmetric tons per year

Tomlinson Cases BLGCC Cases

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Emission reductions for the whole US industryAggressive Scenario

~100% market penetration by 2035P&P industry growth 1% per yearincrease in efficiency of energy use compensates industry growth (total energy use is fixed → electricity exports increase)average US emissions from DOE forecastsevaluate NET reductions with respect to Tomlinson, 2008

Net Reduction metric tons over period 2008-2035

CO2 624,774,878SO2 2,739,265NOx 959,697CO 688,958VOC 120,857PM 475,581CH4 9,519TRS 31,149

High T Utility Scale

BLGCCs can increase very significantly the efficiency of energy recovery from biomass in the P&P industryWith BLGCC, P&P industry can become a large exporter of (mostly renewable) electricityThe higher energy efficiency of BLGCC comes together with large reductions of emissionsMill Integration issues are significant but don’t seem to be subject to technical gaps. Main impact is on costs.Sulfur recovery and variation of kiln load are crucial to improve performances (and limit costs)Further increases in efficiency of renewable energy use can be expected by coupling BLGCC with biomass gasificationEconomic assessment is underway

Conclusions

19

AcknowledgementsBob Gemmer (DOE)John Huyck (Mead-WestVaco)Del Raymond, Denny Hunter, Craig Brown (Weyerhaeuser)Paul Tucker (International Paper)Ben Thorp and Karl Morency (Georgia Pacific)Richard Campbell (AFPA)Tom Johnson (Southern Company)Martha Rollins and Les Reardon (TVA)Gerard Closet (consultant)Ried Miner (NCASI)Shawna McQueen (Energetics)Elmer Fleischman (Idaho National Energy Lab)Bo Oscarsson and John Lewis (Fluor)Sam Tam and King Ng (Nexant)Jarmo Kaila and Tervo Olavi (Andritz)Scott Sinquefield (IPST)Adriaan van Heinenengen (Univ. Of Maine)Hassan Jameel (U. of North Carolina)Ingvar Landalv (Chemrec)

Lee Rockvam & Ravi Chandran (ThermoChem)Niklas Berglin (STFI)Jim Frederick (Chalmers Univ.)Michael Ryan (consultant)Dale Simbeck (SFA Pacific)Nathanael Greene (NRDC)Jim WolfMichael Farmer (Georgia Inst. of Tech.)

DOE, AFPA, Southern Company, TVA for financial support