An Introduction to Biochar With an Emphasis on Its Properties

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An In

tro

duc

tio

n to Bi

och

ar

with a

n

Emphasis on its Properties and Potential

for Climate Change Mitigation

Jim Amonette Jim Amonette

Pacific Northwest National Laboratory Pacific Northwest National Laboratory

Richland, WA 99352 USA Richland, WA 99352 USA PNW

PNW BiochBiocharar InitiInitiative ative MeetiMeetingng 21 May 2009

21 May 2009

PNNL-SA-66736 PNNL-SA-66736

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Outline

What is Biochar? What is Biochar? How is it Made? How is it Made? Pyrolysis

Pyrolysis and and Hydrothermal Hydrothermal Carbonization Carbonization ProcessesProcesses Feedstocks

Feedstocks Yields

Yields

What are its Properties? What are its Properties?

Physical Physical Chemical Chemical

How can it be Used? How can it be Used?

Energy Energy Soil Fertility Soil Fertility Carbon Sequestration Carbon Sequestration

Where does it fit in the Environmental Technology Landscape? Where does it fit in the Environmental Technology Landscape? Summary

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JE Amonette 24Apr2009

What is Biochar?

“Bioch

“Biochar

ar is a fine-g

is a fine-graine

rained charc

d charcoal high in o

oal high in organ

rganic carbo

ic carbon

n

and largely resistant to decomposition. It is produced

from py

from pyrolys

rolysis

is of plan

of plant and was

t and waste feed

te feedstoc

stocks. As a soi

ks. As a soil

l

amen

amendmen

dment, biocha

t, biocharr creat

creates a recalc

es a recalcitrant so

itrant soil carbo

il carbon

n

pool that is carbon-negative, serving as a net

withdrawal of atmospheric carbon dioxide stored in

highly recalcitrant soil carbon

highly recalcitrant soil carbon stocks. The enhanced

stocks. The enhanced

nutrient retention capacity of

nutrient retention capacity of biochar-amend

biochar-amended soil not

ed soil not

only reduces the total fertilizer requirements, but also

the climate and environmental impact of

the climate and environmental impact of croplands.”

croplands.”

(Inte

(Internatio

rnational Bioc

nal Biochar

har Initia

Initiative Scie

tive Scientific Ad

ntific Adviso

visory

ry

Committee)

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What is Biochar?

Product

Solid product resulting from advanced thermal degradation of Solid product resulting from advanced thermal degradation of biomass

biomass

Technology

Biofuel

Biofuel —process heat, bio-oil, and gases (steam, volatile —process heat, bio-oil, and gases (steam, volatile HCs)HCs)

Soil Amendment

Soil Amendment —sor —sorbent fobent for cationr cationss and orgaand organics, linics, liming ageming agent,nt, inoculation carrier

inoculation carrier

Climate Change Mitigation

Climate Change Mitigation —highly recalcitrant pool for C, —highly recalcitrant pool for C, avoidance of N

avoidance of N₂₂O and CHO and CH₄₄ emissions, carbon negative energy,emissions, carbon negative energy, increased net primary productivity (NPP)

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JE Amonette 24Apr2009 JE Amonette 24Apr2009

Ho

w

is

Bi

oc

ha

r

Ma

de

?

Major Techniques: Major Techniques: Slow Pyrolysis Slow Pyrolysis

traditional (dirty, low char yields) and

traditional (dirty, low char yields) and modern (clean, high char yields)modern (clean, high char yields) Flash Pyrolysis

Flash Pyrolysis

modern, high pressure, higher char

modern, high pressure, higher char yieldsyields Fast Pyrolysis

Fast Pyrolysis

modern, maximizes bio-oil production, low char yields modern, maximizes bio-oil production, low char yields Gasification

Gasification

modern, maximizes bio-gas production, minimizes bio-oil production, modern, maximizes bio-gas production, minimizes bio-oil production, low char yields but highly recalcitrant

low char yields but highly recalcitrant Hydrothermal Carbonization

Hydrothermal Carbonization

under development, wet feedstock, high pressure, highest “char” under development, wet feedstock, high pressure, highest “char” yield but quite different composition and probably not

yield but quite different composition and probably not as recalcitrantas recalcitrant as py

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Slow Pyrolysis—Continuo

us Auger

Feed

Gas Gas turbine turbine Hopper Hopper Heat Heat Flue Flue gas gas Exhaust gas Exhaust gas and heat and heat Generator Generator Cyclone Cyclone Dryer Dryer Pyrolysis Pyrolysis gases gases Lignocellulosic Lignocellulosic feedstock feedstock Pyrolysis Pyrolysis reactor reactor Feeder Feeder Motor Motor Char Char Biochar Biochar storage storage Combustor Combustor Steam Steam Air Air Gas Gas cleaner cleaner and and separator separator Electricity

Electricity AirAir

Mill Mill Gas Gas turbine turbine Hopper Hopper Heat Heat Flue Flue gas gas Exhaust gas Exhaust gas and heat and heat Generator Generator Cyclone Cyclone Dryer Dryer Pyrolysis Pyrolysis gases gases Lignocellulosic Lignocellulosic feedstock feedstock Lignocellulosic Lignocellulosic feedstock feedstock Pyrolysis Pyrolysis reactor reactor Pyrolysis Pyrolysis reactor reactor Feeder Feeder Motor Motor Char Char Biochar Biochar storage storage Combustor Combustor Steam Steam Air Air Gas Gas cleaner cleaner and and separator separator Electricity

Electricity AirAir

Mill Mill

courtesy Robert Brown courtesy Robert Brown

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Fas

t Pyro

lys

is

Fl

uid

ize

d Bed Re

act

or

Brown (2009) Brown (2009) Mill Mill Air Air Quencher Quencher Bio-oil Bio-oil Bio-oil Bio-oil storage storage Hopper Hopper Fluidizing gas Fluidizing gas Flue Flue gas gas Vapor, gas, Vapor, gas, char char products products Cyclone Cyclone Combustor Combustor Pyrolysis gases Pyrolysis gases Lignocellulosic Lignocellulosic feedstock feedstock Pyrolysis Pyrolysis reactor

reactor CharChar

Feeder Feeder Motor

Motor BiocharBiochar_storage_storage

Mill Mill Air Air Quencher Quencher Bio-oil Bio-oil Bio-oil Bio-oil storage storage Bio-oil Bio-oil storage storage Hopper Hopper Fluidizing gas Fluidizing gas Flue Flue gas gas Vapor, gas, Vapor, gas, char char products products Cyclone Cyclone Combustor Combustor Pyrolysis gases Pyrolysis gases Lignocellulosic Lignocellulosic feedstock feedstock Pyrolysis Pyrolysis reactor reactor Pyrolysis Pyrolysis reactor

reactor CharChar

Feeder Feeder Motor

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Pyrolysis

Competition between three processes as biomass is

heated:

Bio

Biochacharr and gand gas foas formarmatiotionn Liquid and tar formation Liquid and tar formation

Gasification and carbonization Gasification and carbonization

Relative rates for these processes depend on:

Highest treatment temperature (HTT) Highest treatment temperature (HTT) Heating rate

Heating rate

Volatile removal rate Volatile removal rate

Feedstock residence time Feedstock residence time

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Comp

etit

ion

Amon

g

Pyro

lysi

s

Proc

esses

Factors favoring

bi

bioc

ocha

harr fo

form

rmat

atio

ion

n

Lower temperature Lower temperature Slower heating rates Slower heating rates Slower volatilization Slower volatilization rates rates Longer feedstock Longer feedstock residence times residence times

In general,

In general, process

process

is

more important than

feedstock in

determining products

of pyrolysis

Eastern Red Maple Wood, Fast Pyrolysis, High Purge Rate Eastern Red Maple Wood, Fast Pyrolysis, High Purge Rate

(Scott et al., 1988) (Scott et al., 1988) 0 0 10 10 20 20 30 30 40 40 50 50 60 60 70 70 80 80 90 90 2 20000 330000 440000 550000 660000 770000 880000 990000 High H

High Heating Tempeeating Tempe rature, Crature, C

Y Y i i e e l l d d w w , , t t % % Char Char Gas Gas Liquid Liquid

Spruce Wood, Slow Pyrolysis, Vacuum Spruce Wood, Slow Pyrolysis, Vacuum

(Demirbas, 2001) (Demirbas, 2001) 0 0 10 10 20 20 30 30 40 40 50 50 60 60 70 70 80 80 90 90 2 20000 330000 440000 550000 660000 770000 880000 990000 High Heating Temperature, C

High Heating Temperature, C

Y Y i i e e l l d d w w , , t t % % Char Char Gas Gas Tar+Liquid Tar+Liquid

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Wood Char Yields from Pyrolysis

Figure from Amo

Figure from Amonette and nette and Joseph (2009Joseph (2009) showing da) showing data of Figueirta of Figueiredoedo et al. (et al. (1989), Demirbas1989), Demirbas (2001), Antal(2001), Antal et al.et al. (2000

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Feedstocks

Essentially all forms of biomass can be converted to biochar Essentially all forms of biomass can be converted to biochar

Preferable forms include: forest thinnings, crop residues (e.g., corn Preferable forms include: forest thinnings, crop residues (e.g., corn

stover, alfalfa stems, grain husks), yard waste, paper sludge, stover, alfalfa stems, grain husks), yard waste, paper sludge, manures, bone meal

manures, bone meal

Trace element (Si, K, Ca, P) and lignin contents vary Trace element (Si, K, Ca, P) and lignin contents vary Lignin content can affect char yields

Lignin content can affect char yields

Ligni

Lignin Content, Tn Content, Temperature, and Char Yieldemperature, and Char Yield Slow Pyrolysis, Vacuum (Demirbas, 2001) Slow Pyrolysis, Vacuum (Demirbas, 2001)

y = 0.39x + 26.76 y = 0.39x + 26.76 R R22_{= 0.99}_{= 0.99} y = 0.33x + 15.29 y = 0.33x + 15.29 R R22_{= 0.96}_{= 0.96} 0 0 5 5 10 10 15 15 20 20 25 25 30 30 35 35 40 40 45 45 50 50 0 0 1100 2200 3300 4400 5500 6600

Biomass Lignin Content, wt% Biomass Lignin Content, wt%

C C h h a a r r Y Y i i e e l l d d , , w w t t % % Char (277 C) Char (277 C) Char (877 C) Char (877 C) Corn Cob

Corn Cob WoodWood

Husks, Shells, Kernels Husks, Shells, Kernels

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What are the

Properties of Biochar?

Pine Wood Char

Corn Cob Char Corn Cob Char Oak Wood Char Oak Wood Char

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Physical Properties

S S l l o o w w F F a a s s t t G G a a s s

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Physical Properties Change with HTT

Downie Downie et alet al., 20., 200909 a a ) ) b b ) ) Kerch

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Physical Structure and

Chemical Properties Depend

on Carbon Bonding Network

Radov

Radovicic et al.et al., 2001, 2001

13

13_{C CP-MAS NMR}_{C CP-MAS NMR}

Amonette et al., 2008 Amonette et al., 2008

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X-ray Diffraction Analysis

Slow Py

Slow Pyrolysrolysisis and Hydrand Hydrotherothermal Charmal Charss (steam present)

(steam present)

Combustion Char (high mineral content) Combustion Char (high mineral content) Gasification and

Gasification and Fas

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Chemical Properties

Slow Pyrolysis

Slow Pyrolysis chars produced in presence of steam at 4chars produced in presence of steam at 475°75°C tend toC tend to be acidic (carboxylic acid groups activated)

be acidic (carboxylic acid groups activated) Fast Pyrolysis

Fast Pyrolysis chars produced in absence of steam at 500°chars produced in absence of steam at 500°C tend toC tend to be slightly basic

be slightly basic Gasificat

Gasification chars pion chars produced iroduced in presencn presence of steam at 700e of steam at 700°°C tend to beC tend to be very basic and make good liming agents

very basic and make good liming agents

S S l l o o w w F F a a s s t t G G a a s s

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Surface Chemistry

0 0 20 2000 40 4000 60 6000 80 8000 1000 1000 1200 1200 O OKKEEB B PPBBEEB B PPCCEEB B PPCCN N OOAAK K PPNNNNLL_‐‐M M PNPNNNLL_‐‐P P PPNNNNLL_‐‐S S HHW W OOKK (CSA)(CSA) WSWS CSBCSB NaOH

NaOH AnalyteAnalyte Na2CO3

Na2CO3 AnalyteAnalyte NaHCO3

NaHCO3 AnalyteAnalyte HCl

HCl AnalyteAnalyte

Slow

Slow PyrolysisPyrolysis (steam)(steam)

Gasification

Gasification (steam)(steam) Fast

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pH-Dependen

t

Exchange Capacities

Oak Feedstock Oak Feedstock -600 -600 -400 -400 -200 -200 0 0 200 200 400 400 600 600 800 800 1000 1000 0 0 22 44 66 88 1100 1122 1144 pH pH I I o o n n S S o o r r p p t t i i o o n n C C a a p p a a c c i i t t y y , , m m e e q q / / k k g g OKEB OKEB OAK OAK OK (CSA) OK (CSA) Sl

Slow ow PPyryrolysis (solysis (s teamteam), 475), 475°°CC

Gasification (steam), 700 Gasification (steam), 700°°CC

Fast P

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How c

an Bi

och

ar

Te

chn

ol

og

y be Use

d?

Generate Carbon-Negative Energy

Soil Amendment

Carbon Sequestration

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Comp

ariso

n o

f B

ioch

ar

Prod

uctio

n M

etho

ds

1.0 1.0 0.16 0.16 5.5 5.5 “lignite”, H “lignite”, H₂₂OO Hydrothermal Hydrothermal Conversion Conversion 0.5 0.5 0.53 0.53 17.7 17.7 Char, tars, CH Char, tars, CH₄₄,, CO CO₂₂, H, H₂₂OO Slow Slow Pyrolysis Pyrolysis 0.15 0.15 0.65 0.65 22.0 22.0 CH CH₄₄, CO, CO₂₂, Bio-, Bio-Oils, H

Oils, H₂₂O, CharO, Char Fast Fast Pyrolysis Pyrolysis Solid C Solid C Production Production Efficiency Efficiency Fossil C Fossil C (Coal) Offset (Coal) Offset Efficiency Efficiency Net Energy Net Energy Released, Released, GJ/t C GJ/t C Products Products Carbonization Carbonization Method Method 1.0 1.0 0.16 0.16 5.5 5.5 “lignite”, H “lignite”, H₂₂OO Hydrothermal Hydrothermal Conversion Conversion 0.5 0.5 0.53 0.53 17.7 17.7 Char, tars, CH Char, tars, CH₄₄,, CO CO₂₂, H, H₂₂OO Slow Slow Pyrolysis Pyrolysis 0.15 0.15 0.65 0.65 22.0 22.0 CH CH₄₄, CO, CO₂₂, Bio-, Bio-Oils, H

Oils, H₂₂O, CharO, Char Fast Fast Pyrolysis Pyrolysis Solid C Solid C Production Production Efficiency Efficiency Fossil C Fossil C (Coal) Offset (Coal) Offset Efficiency Efficiency Net Energy Net Energy Released, Released, GJ/t C GJ/t C Products Products Carbonization Carbonization Method Method Combustion Combustion COCO₂₂, H, H₂₂OO 38.438.4 0.970.97 0.01?0.01?

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T

h

e B

i

o

f

u

e

l

N

₂₂

O Problem

Recent

Recent work

work (Crutz

(Crutzen

en et al.,

et al., 2007,

2007, Atmos.C

Atmos.Chem. Ph

hem. Phys.

ys.

Disc. 7:11191; Del Grosso, 2008, Eos 89:529) suggests

that globally, N

₂₂

O pro

O product

duction av

ion averag

erages at 4

es at 4% (+/

% (+/-- 1%) o

1%) off

N that is fixed

IPCC reports have accounted only for field measurements

of N

₂₂

O emitted, which show values close to 1%, but

ignore

ignore other

other indicator

indicators discu

s discussed b

ssed by Cru

y Crutzen

tzen et al

et al..

If 4%

If 4% is corr

is correct, t

ect, then com

hen combustion

bustion of biof

of biofuels

uels except

except for

for

high cellulose (low-N) fuels will actually increase global

warming relative to petroleum due to large global warming

potential of N

₂₂

O

Bio

Biocha

charr avo

avoids t

ids thi

his iss

s issue

ue

Ties up reactive N in a stable pool Ties up reactive N in a stable pool Eliminates potential N

Eliminates potential N₂₂O emissions from manures and otherO emissions from manures and other biomass sources converted to biochar

biomass sources converted to biochar Decreases N

Decreases N₂₂O emissions in field by imO emissions in field by improving N-fertilizer useproving N-fertilizer use efficiency and increasing air-filled porosity

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Soil Amendment

Biocha

Biocharr typictypically ally increaincreases ses catiocationn exchaexchange nge capaccapacity, ity, and and hencehence retention of NH

retention of NH₄₄++_{, K}_{, K}++_{, Ca}_{, Ca}2+2+_{, Mg}_{, Mg}2+2+

N from original biomass, however, may

N from original biomass, however, may not be readily availablenot be readily available P, on the other hand, is generally retained and available

P, on the other hand, is generally retained and available Liming agent

Liming agent

Enhanced sorption of organics (herbicides, pesticides, enzymes) Enhanced sorption of organics (herbicides, pesticides, enzymes) (Good? Bad?)

(Good? Bad?) Some eviden

Some evidence for increasece for increased mycorrhizd mycorrhizalal populapopulationstions, rhizobial, rhizobial infection rates

infection rates

Used as carrier for microbially-based environmental remediation Used as carrier for microbially-based environmental remediation Lowers bulk density

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Iden

tific

atio

n of

best

bioc

har

type

for

soil

application

Criteria

Near-neutral pH Near-neutral pH

High ion exchange capacities (CEC and AEC) High ion exchange capacities (CEC and AEC) Moder

Moderate hydate hydrophorophobicitybicity to retaito retain organn organicsics High stability to oxidation

High stability to oxidation Low volatile content

Low volatile content Pre-treated with NH

Pre-treated with NH₄₄++ _{to avoid induced N deficiency}_{to avoid induced N deficiency}

Recommendation

Steam-activated Steam-activated

Carbonized (i.e., treated to higher temperature to remove Carbonized (i.e., treated to higher temperature to remove volatiles)

volatiles) Slow

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Carbon Sequestration

Why?

Decrease atmospheric Decrease atmospheric GHG levels GHG levels Stop acidification of Stop acidification of oceans by CO oceans by CO₂₂ absorption absorption

We only have one Earth We only have one Earth

How?

Create stable C pool Create stable C pool using biochar

using biochar

Use energy to offset Use energy to offset fossil-C emissions fossil-C emissions Avoid emissions of N Avoid emissions of N₂₂OO and CH and CH₄₄

Increase net primary Increase net primary productivity (NPP) productivity (NPP)

Adapted from IPCC AR4 WGI with updated inventory and flux Adapted from IPCC AR4 WGI with updated inventory and flux datadata Pre-industrial values (1750) Pre-industrial values (1750) Anthropogenic changes (2005) Anthropogenic changes (2005) 7. 7. 2 2 Fossil Fuels Fossil Fuels 3700 3700 --319319 Atmosphere Atmosphere 597 597 + 211+ 211 Surface Ocean Surface Ocean 900 900 + 22+ 22

Intermediate and Deep Ocean Intermediate and Deep Ocean 37100

37100 + 120+ 120 Vegetation, Soil, and

Vegetation, Soil, and Detritus Detritus 2477 2477 --3434

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Observed and Projected

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Factors Affecting Global Warming (100-year

timeframe)

IPCC (2007) WG1-AR4, p. 136 IPCC (2007) WG1-AR4, p. 136

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Properties of Key Greenhouse Gases

5200 5200 10900 10900 11000 11000 23000 23000 69 69 CFC-12 12

Due to its short half-life Due to its short half-life (precipitation!), H

(precipitation!), H₂₂O is a feedbackO is a feedback gas, rather than forcing warming gas, rather than forcing warming

289 289 72 72 1 1 Global Global Warming Warming Potential Potential (20-yr) (20-yr) 298 298 25 25 1 1 Global Global Warming Warming Potential Potential (100-yr) (100-yr) ~0.4 ~0.4 ~0.011 ~0.011 H H₂₂OO 153 153 214 214 79 79 N N₂₂OO 7.6 7.6 26 26 8.3 8.3 CH CH₄₄ 1 1 1 1 30-325* 30-325* CO CO₂₂ Global Global Warming Warming Potential Potential (500-yr) (500-yr) Relative Relative Radiative Radiative Efficiency Efficiency Atmos. Atmos. Half-life, Half-life, yr yr

*Decay rate has sever

*Decay rate has several pathways with al pathways with different rates. different rates. About 22% of theAbout 22% of the CO

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Projected Atmospheric Carbon Levels and

Associated Global Warming

IPCC (2007)

IPCC (2007) WG1-AR4, SPM, p. WG1-AR4, SPM, p. 14, modified to s14, modified to showhow zone where irreversible warming of Greenland ice sheet is zone where irreversible warming of Greenland ice sheet is projected to occur (ibid., p. 17)

projected to occur (ibid., p. 17)

0 0 500 500 1000 1000 1500 1500 2000 2000 2500 2500 1 1 7 7 5 5 0 0 2 2 0 0 0 0 5 5 C C o o n n s s t t a a n n t t 2 2 1 1 0 0 0 0 B B 1 1 2 2 1 1 0 0 0 0 A A 1 1 B B 2 2 1 1 0 0 0 0 A A 2 2 C C u u m m u u l l a a t t i i v v e e A A n n t t h h r r o o p p o o g g e e n n i i c c C C i i n n A A t t m m o o s s p p h h e e r r e e ( ( G G t t C C ) )

Irreversible warming threshold? Irreversible warming threshold?

3 3 7 7 9 9 2 2 8 8 0 0 6 6 0 0 0 0 8 8 5 5 0 0 1 1 2 2 5 5 0 0 Atmospheric concentration Atmospheric concentration of CO of CO₂₂, ppm, ppm

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What to do . . .

Eliminate the C-positive, accentuate the C-negative!

Minimize fossil fuel inputs

Improve energy efficiency Improve energy efficiency

Point-source capture/sequestration of CO

Point-source capture/sequestration of CO₂₂

Replace with biofuels

Replace with biofuels, nuclear (???$$$), nuclear (???$$$)

Maximize terrestrial sink (diffuse

capture/sequestration)

Afforestation

Low-input and perennial cropping systems

Implement C-negative energy technologies

Biomass combustion with CO

Biomass combustion with CO₂₂ sequestrationsequestration

Bio

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Creating a Stable Carbon Pool with Biochar

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Human-Appro

priated Net

Primary Productivity

29% of all C fixed

29% of all C fixed by photosynthesis abovegroundby photosynthesis aboveground

(ca. 10.2 GtC/yr) is currently used by humans! (ca. 10.2 GtC/yr) is currently used by humans! Of this 1.5 GtC/yr is unused crop residues, Of this 1.5 GtC/yr is unused crop residues, manures, etc.

manures, etc.

An additional 1.8 GtC/yr) is not fixed due to prior An additional 1.8 GtC/yr) is not fixed due to prior human activities (e.g., land degradation) and human activities (e.g., land degradation) and current land use

current land use

Current fossil-C emissions are ca. 8 GtC/yr Current fossil-C emissions are ca. 8 GtC/yr Increased productivity and expanded use of Increased productivity and expanded use of resid

residues from bioues from biocharchar produproduction coction could have auld have a

significant impact on global C budget significant impact on global C budget

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Carbon Sequestration using Biochar

Sl

Slow pyow pyrorolylysisiss bibiocochaharsrs arare hige highlhlyy recalcitrant in soils with half-lives of recalcitrant in soils with half-lives of 100-900 years

100-900 years

Sensitivity analysis suggests that Sensitivity analysis suggests that half lives of 80 years or more are half lives of 80 years or more are sufficient to provide a credible C sink sufficient to provide a credible C sink Recent evidence using

Recent evidence using 1414_C-labeled_C-labeled

bio

biochacharr shoshows no evws no evideidence fonce forr enhanc

enhanced rated rates of es of soil soil humichumic carboncarbon degradation in agricultural soils

degradation in agricultural soils (Ku

(Kuzyazyakovkov et aet al., 2l., 2009009))

No evidence for polyaromatic No evidence for polyaromatic

hydrocarbon (PAH) contamination hydrocarbon (PAH) contamination has been seen

has been seen

Down-side risks seem very small Down-side risks seem very small

Estimates of Half-life in Soils Estimates of Half-life in Soils

(Slow Pyrolysis Biochars) (Slow Pyrolysis Biochars)

0 0 200 200 400 400 600 600 800 800 1000 1000 1200 1200 1400 1400 5 5 1100 1155 2200 2255 3300 3355 Mean Annual Temp, C

Mean Annual Temp, C

T T i i m m e e

, , y y e e a a r r s s Cheng et al. (2008) Cheng et al. (2008) Kuzyakov et al. (2009) Kuzyakov et al. (2009)

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IBI Es

(35)

The last resort ?

To balance the C

To balance the C cycle, annualcycle, annual human harvest of fixed biomass human harvest of fixed biomass would have to double from about would have to double from about 8.2

8.2 GtGt C cC currurrentently ly (Ha(Haberberll et et al.al.,, 2008)

2008) to to more more than than 15 15 GtGt C. C. ThisThis would amount to harvesting about would amount to harvesting about 40% of above-ground biomass C, 40% of above-ground biomass C, and is comparable to levels of and is comparable to levels of biomass C appropriation seen in biomass C appropriation seen in India

India today today (Habe(Haberlrl et al.et al., 200, 2008).8).

The annual diversion of 11.3% of The annual diversion of 11.3% of globa

global biol biomass mass carbocarbon (7 Gn (7 Gtt C,C,

roughly one-fifth of all above-ground roughly one-fifth of all above-ground biomass C produced) to a

biomass C produced) to a pyrolysispyrolysis industry would have a profound industry would have a profound impact on the global ecology and impact on the global ecology and would be considered a last resort. would be considered a last resort.

See James Lovelock Interview See James Lovelock Interview

http://www.guardian.co.uk/science/video/2009/ http://www.guardian.co.uk/science/video/2009/ apr/22/james-lovelock-gaia-space-biochar

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Methane and Traditional Methods

Traditional methods Traditional methods without energy without energy recovery generate recovery generate methane methane Some decrease in Some decrease in mitigation potential mitigation potential results results Difference in biochar Difference in biochar yield is far more

yield is far more important

important

These methods still These methods still yield a positive result yield a positive result

Woody Biomass Woody Biomass No Energy Recovery No Energy Recovery 0 0 100 100 200 200 300 300 400 400 500 500 600 600 0 0..00 00..55 11..00 11..55 22..00 22..55 33..00 CH

CH44Emissions (Percent of all C Emissions)Emissions (Percent of all C Emissions)

G G l l o o b b a a l l W W a a r r m m i i n n g g M M i i t t i i g g a a i i o o n n P P o o t t e e n n t t i i a a l l , , g g C C O O 2 2 - - C C e e q q / / k k g g d d r r y y b b i i o o m m

a a s s s s 36% Biochar Yield 36% Biochar Yield 30% Biochar Yield 30% Biochar Yield 20% Biochar Yield 20% Biochar Yield 10% Biochar Yield 10% Biochar Yield Traditional kilns Traditional kilns w/ no energy recovery w/ no energy recovery Modern Modern Slow Slow Pyrolysis Pyrolysis

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Impact of Energy Recovery

Recovery of energy Recovery of energy released during released during pyr

pyrolyolysissis impimprovroveses mitigation potential mitigation potential significantly significantly Modern pyrolysis Modern pyrolysis methods should be methods should be implemented wherever implemented wherever possible possible Economic decision Economic decision

All Sustainable Biomass All Sustainable Biomass

70% Pyrolysis Energy Recovery Efficiency 70% Pyrolysis Energy Recovery Efficiency

0 0 100 100 200 200 300 300 400 400 500 500 600 600 0 0..00 00..55 11..00 11..55 22..00 22..55 33..00 CH

CH44Emissions (Percent of all C Emissions)Emissions (Percent of all C Emissions)

G G l l o o b b a a l l W W a a r r m m i i n n g g M M i i t t i i g g a a i i o o n n P P o o t t e e n n t t i i a a l l , , g g C C O O 2 2 - - C C e e q q / / k k g g d d r r y y b b i i o o m m

a a s s s s 36% Biochar Yield 36% Biochar Yield 30% Biochar Yield 30% Biochar Yield 20% Biochar Yield 20% Biochar Yield 10% Biochar Yield 10% Biochar Yield Traditional kilns Traditional kilns w/ no energy recovery w/ no energy recovery Modern Modern Slow Slow Pyrolysis Pyrolysis

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Wh

er

e do

es B

io

ch

ar

Fi

t?

Offers a flexi

Offers a flexible blend of biofuble blend of biofuelel energenergy, soil fertily, soil fertility enhanity enhancemencement,t, and climate change mitigation

and climate change mitigation

Limited by biomass availability and, eventually, land disposal area Limited by biomass availability and, eventually, land disposal area How much bi

How much biomass caomass can be made availan be made available for biochble for biocharar produproduction vs.ction vs. other uses?

other uses? Crop-d

Crop-derived bioerived biofuelsfuels cannocannot supply all the world’t supply all the world’s energy needss energy needs

Maximum

Maximum estimates suggest 50% of current, 33% of estimates suggest 50% of current, 33% of futurefuture Biodiversity (HANPP)?

Biodiversity (HANPP)? N

N₂₂O?O?

Perhap

Perhaps best use of harves best use of harvested biosted biomass is to makmass is to make biochae biocharr to drawto draw down atmospheric C levels and enhance soil productivity, with energy down atmospheric C levels and enhance soil productivity, with energy production as a bonus (but not the driving force).

production as a bonus (but not the driving force).

This will require government incentives (C credits/taxes?) and

This will require government incentives (C credits/taxes?) and aa

change in the way we value cropped biofuels change in the way we value cropped biofuels

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Further Information and

Acknowledgmen

ts

Inte

Internat

rnationa

ional Bi

l Biocha

ocharr Init

Initiati

iative

ve

(www.biochar-international.org) (www.biochar-international.org)

New book:

Bioch

Biochar

ar for E

for Enviro

nvironmen

nmental M

tal Manag

anagemen

ement:

t:

Science and

Science and Technology,

Technology,

Earthscan, 2009 (in press)

Nort

North Amer

h American B

ican Bioch

iochar

ar Conf

Conferen

erence 2009

ce 2009

University of Colorado at Boulder, August 9-12,

University of Colorado at Boulder, August 9-12, 20092009 Research supported by

Research supported by

USDOE Office of Fossil Energy through the

USDOE Office of Fossil Energy through the National Energy TechnologyNational Energy Technology

Laboratory

USDOE Office of Biological and Environmental Research (OBER) through

the Carbon Sequestration in

the Carbon Sequestration in Terrestrial Ecosystems (CSiTE) project.Terrestrial Ecosystems (CSiTE) project.

Research was

Research was performed at the performed at the W.R. Wiley W.R. Wiley Environmental Environmental MolecularMolecular SciencesSciences

Laboratory, a national scientific user facility at the

Laboratory, a national scientific user facility at the Pacific Northwest NationalPacific Northwest National

Laboratory (PNNL) sponsored by the

Laboratory (PNNL) sponsored by the USDOE-OBER.USDOE-OBER.

PNNL is operated for

PNNL is operated for the USDOE by Battelle Memorial Institute under the USDOE by Battelle Memorial Institute under contractcontract

DE AC06 76RL01830.

PNNL-SA-64398

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