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Biocoal for Renewable Biomass Power GenerationBiomass Power Generation

Copyright – Bepex International – 2011 – All Rights Reserved

AcknowledgementAcknowledgement

Project funding provided by customers of Xcel Energy through acustomers of Xcel Energy through a

grant from the Renewable Development FundDevelopment Fund.


Why Biocoal?Why Biocoal?

• Coal is the largest source of energy for electricity – $340B Global Market

• Coal use is expected to continue to grow for many years• Coal use is the second largest greenhouse gas source• Regulatory mandates to increase renewable energy and

curb greenhouse gas emissions• Large existing infrastructure and generation capacity


– Over 1,200 coal powered plants in the U.S. alone

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Raw Biomass: ChallengesRaw Biomass: Challenges

• Pulverized coal power plant modifications required• Transportation and storage modifications required• Poor Hardgrove Grindability Index (HGI)g y• Propensity of raw biomass to rot• Pellets fall apart when exposed to moist environmentsp p• Relatively low bulk and energy densities

Copyright – Bepex International – 2011 – All Rights Reserved2

OpportunityOpportunity

Opportunity for an industrial scale process technologythat produces a product from raw biomass that iscompatible with existing coal infrastructure and supplyp g pp ychains: Torrefaction


BiocoalBiocoal• Torrefaction mild pyrolysis: 200 – 320° C without oxygen• Upgrades raw biomass into a coal-like substance or “biocoal”• Increased energy (30%) and bulk density• Increased grindability (HGI 2.5X) over raw biomass• Less biologically active – easier import / export

h d h b l k b l d l b b• More hydrophobic – lacks ability to readily absorb moisture• Leverages coal transportation and storage infrastructure

N h i l bi d i d d bi l


• No chemicals or binders required to produce biocoal

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Project ScopeProject Scope• Develop, optimize and demonstrate a torrefaction and p p

densification (“biocoal”) process to improve storage capabilities, handling, usability and uniformity for the

d f bl b l d l hproduction of renewable baseload electricity, heat, or syngas.D l f d l d di f h• Develop a fundamental understanding of the underlying economics of the overall process from the field to post combustion ash analysis


field to post combustion ash analysis.

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Fall 2008 Biomass CollectionFall 2008 Biomass Collection


Pilot Scale (10 MT/Day) Mass Balance

HEAT RECOVERY GAS DRYING

BIOMASS: 641 KGS/HOURWATER: 641 KGS/HOUR

WATER: 641 KGS/HOUR

BIOMASS: 641 KGS/HOUR

TORREFACTION

TORREFIED BIOMASS417 KGS/HOUR

INERT GAS

TORREFIER OFF GAS VOLATILES: 224 KGS/HOUR

HEAT RECOVERY

DENSIFICATION

TORREFIED BIOMASSTORREFIED BIOMASS417 KGS/HR

COOLING MEDIUM

COOLING MEDIUM COOLING


FINAL PRODUCT417 KGS/HR

TO CUSTOMERNOTE: Representation of10 MT / day pilot plant 7

Biocoal: Similar to CoalBiocoal: Similar to CoalBiocoal

(Corn Stover)Sub-Bituminous

Coal(Corn Stover) CoalCaloric Value (btu/lb.) 8701 8313Fixed Carbon (%) 26.8% 34.6%V l il (%) 64 6% 28 7%Volatiles (%) 64.6% 28.7%Ash (%) 7.6% 8.2%Sulfur (%) 0.1% 0.7%Moisture (%) 1.1% 28.5%Bulk Density (lbs/ft3) >45 >45Hardgrove Grindability Index >35 50


Hardgrove Grindability Index >35 50All Values are on an "As Received" basis

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Pilot Scale Pulverized Coal Co-Firing TrialPilot Scale Pulverized Coal Co Firing Trial

• Successfully completed in August 2009• Tested torrefied and densifed corn stover• Co-firing at 10% & 30% with sub-bituminous coal• Flue gas composition (O2, CO2, CO, SO2, NOx)• Fouling potential through the use of fouling probesg p g g p• Heat flux measurements & electrostatic precipitator ash

collection


Emissions Reduction vs Baseline (100% Coal)Emissions Reduction vs. Baseline (100% Coal)

SO2(lb/ b )

NOx(lb/ b )(lb/mmbtu) (lb/mmbtu)

10% Bi l (C S ) 17 0% 15 6%10% Biocoal (Corn Stover) 17.0% 15.6%

30% Biocoal (Corn Stover) 30.0% 28.3%


Stoker Grate Co-firing Trials: District EnergyStoker Grate Co firing Trials: District Energy

• 10% trial successfully completed in March 201030% l f ll l d J l 2010• 30% trial successfully completed in July 2010

• Torrefied and densifed corn stover biocoal tested• Co firing at 10 & 30% ratio with high rank eastern sub• Co-firing at 10 & 30% ratio with high rank eastern sub-

bituminous coal• Flue gas composition (O2, CO2, CO, SO2, NOx)g• Boiler operating parameters (heat rate, over-fire, etc.)• Visual empirical inspection in stoker against baseline


Emissions Reduction vs Baseline (100% Coal)Emissions Reduction vs. Baseline (100% Coal)

SO2(lb/ b )

NOx(lb/ b )(lb/mmbtu) (lb/mmbtu)

10% C S Bi l 11 7% 34 3%10% Corn Stover Biocoal 11.7% 34.3%

30% Corn Stover Biocoal 23.81% 41.30%


Commercialization EconomicsCommercialization Economics• Production costs: $17.85 USD / ton• Feedstock costs: $132.83 USD / ton• Price of biocoal: $151.27 USD / ton (FOB Plant)

E i d i l l l i• Estimated commercial scale plant construction cost– $31.28 M USD (Year 2011) turn-key – without CHP system

150 000 ton / annum biocoal production capacity– 150,000 ton / annum biocoal production capacity– 60% debt – 40% equity capital structure– Interest Rate: 7.0% Debt / Required IRR: 15.0% Equity


– Estimates do not include land or site improvement costs

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Biocoal Production CostsBiocoal Production Costs

% USD / Ton$ Raw Feedstock

32.6% $ 5.75 Utilities25 5% $ 4 50 Salaries & Benefits25.5% $ 4.50 Salaries & Benefits5.7% $ 1.00 General & Admin.18.1% $ 3.20 Main. Expense18.1% $ 3.20 Depreciation

100.0% $ 17.65 Costs$ 1 02 mmbtu


$ 1.02 mmbtu

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Co-Firing Economic Sensitivity AnalysisCo Firing Economic Sensitivity Analysis

Negative Baseline Positive-20% -10% 0% +10% +20%

Biomass Price ($/ton) (1) $57.90 $65.14 $72.38 $79.62 $86.86Biomass Moisture (%) (2) 13.6% 15.3% 17.0% 18.7% 20.4%

Natural Gas ($/mmbtu) (3) $3.50 $3.94 $4.38 $4.82 $5.26Coal Delivered ($/mmbtu) (4) $1.51 $1.70 $1.89 $2.08 $2.27

Debt Interest Rate (%) (5) 5.6% 6.3% 7.0% 7.7% 8.4%Equity Required Rate (%) (6) 12.0% 13.5% 15.0% 16.5% 18.0%Biocoal Plant (M $USD) (7) $25.03 $28.15 $31.28 $34.41 $37.54

CO2 Value ($/MT) (8) $1.60 $1.80 $2.00 $2.20 $2.40SO2 Value ($/ton) (9) $13.27 $14.93 $16.59 $18.25 $19.91

NOX Value ($/ton) (10) $36.02 $40.53 $45.03 $49.53 $54.04Hg Abatement ($/lb.) (11) $26,776 $30,123 $33,470 $36,817 $40,164


g ($ ) ( ) $ , $ , $ , $ , $ ,REC Value ($/MWh) (12) $2.00 $2.25 $2.50 $2.75 $3.00

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Sensitivity Analysis: 10% Co-FiringSensitivity Analysis: 10% Co Firing0.050

(¢/k

wh)

0.020

0.030

0.040

of E

lect

rici

ty (

0.000

0.010

ange

in P

rice

o

-20%-10%0%10%

Cha 10%

20%


Economic Model Input Variables16

Est Yearly Emission Reductions: Sherco Unit #1Est. Yearly Emission Reductions: Sherco Unit #110% Co-Firing 30% Co-Firing

CO480,464 1,441,391 (tons)

CO2( )

10.3% 30.8% (%)

SO1,074 1,937 (tons)

SO2( )

15.8% 28.4% (%)

668 1,181 (tons)NOx

668 1,181 (tons)17.0% 30.0% (%)

9 28 (lb )


Hg9 28 (lbs.)

5.2% 15.6% (%)

17

Estimated Economic Impact: 30%Estimated Economic Impact: 30%• Investments: $156.4 million – debt and equity• Annual Payments to Minnesota Biomass Suppliers: $103.2 million• Direct Full-Time Jobs Created: 75+• Indirect Jobs Created: 75+ (Harvesting, Storage & Transport)J ( g g p )• Annual CO2 Emissions Avoided: 1,441,391 tons CO2

• Annual Renewable Power Generated: 1,306,485 MWh– Enough for 151,015 HomesEnough for 151,015 Homes

• Annual Increase in Residential Electric Customer Bill: $9.90• Average Price of Electricity for Xcel Customers: $0.07797

I i El i i P i 1 10%


• Increase in Electricity Prices: 1.10%

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Project Results:Project Results:• Proved technical feasiblity of collecting corn stover biomass• Proved technical feasibily of continuous biomass torrefaction

and densification to produce biocoalP d bi l fi i h d d ifi i k• Proved biocoal finished product specifications meet known minimum requirements for use in pulverized coal boilers, stoker grates, and gasification systems

• Proved feasiblity and statistically relevant reductions in emission profiles during use in conversion technologies.P d i f ibl l i l i


• Proved economics are feasible at lower inclusion rates at existing pulverized coal electricity production facilities.

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Project Conclusions:Project Conclusions:• Biocoal (corn stover), while some technical questions remain,

for the generation of renewable, near carbon neutral baseloadelectric power in existing pulverized coal electricity power generation facilities appears to be economically and technicallygeneration facilities appears to be economically and technically feasible at lower inclusion rates.


Questions?Questions?


Contact Information:

Kevin P. Grotheim, BSME, MBABepex International, LLC

333 Taft Street NEMinneapolis, MN 55413

+1 612 627 [email protected]


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