Biochar Basics:An Introduction about theWhat and Why of Biochar

Paul S. Anderson, PhD AKA “Dr. TLUD” (TEE-lud)

V.P. of Chip Energy Inc Specialist in micro-gasification psanders@ilstu.eduSlide-set modified and presented

by:

Hugh McLaughlin, PhD, PE Director of Biocarbon

Research Alterna Biocarbon Inc. hmclaughlin@alternabiocarbon.com

(Add presenter’s identification)

Version 1 of these slides was presented at the 2009 Northeast Biochar Symposium, November 13 at

the University of Massachusetts Amherst (Released for general distribution and use by others.)

Biochar Defined:

• The placement of charcoal into soils.

• The presence of nearly pure carbon in soils, in the form of amorphous graphite.

• NOT carbon that is in living organisms.

• NOT fossil carbon, as in coal, oil, or natural gas.

His ancestors accomplished soil improvements that modern science is trying to understand and replicate.

Latosol vs. Terra Preta (Dark Earth)

Terra preta is excellent soil with high presence of charcoal (biochar).

Terra preta might be from “slash and char” practices, but NOT from current “slash-and-burn” agricultural practices.

• Was biomass; now has charcoal-like properties.

• Significant carbon content, but more than just carbon that has been sequestered:

• Internal surface area and adsorption properties.

• CEC = cation exchange capacity, better fertilizer retention and less field runoff.

•Significant synergisms with soil microbes over time – nitrogen fixers and other good “bugs.”

Summary of Biochar Properties

Half-life of biochar is ~1400 years.

Conclusion # 1:

• There is something about abundant charcoal in soils that can be highly beneficial to plants.

• The benefits last for at least hundreds of years.• Biochar has potential for improving soils and

feeding people, especially where soils are weak.• ONLY possible with charcoal:

– NOT by putting coal dust into soils.– NOT by adding manure or other organic

material.

Basic Forms andTransformations of Carbon:

Elemental Carbon C (solid)

Activated charcoal

Regular charcoal

Graphite

Carbon black (soot)

Coke (from coal)

Oxide gases C + O

CO & CO2

Hydrocarbons C + H

Coal, oil, gases

Biomolecules C + H + O Carbohydrates, Sugars, Cellulose, Lignin, & much more in living and dead biomass.

Basic Forms andTransformations of Carbon:

Elemental Carbon C (solid)

Activated charcoal

Regular charcoal

Graphite

Carbon black (soot)

Coke (from coal)

Oxide gases C + O

CO & CO2

Hydrocarbons C + H

Coal, oil, gases

Add H2O and

photosynthesis by plants

Add Oxygen: Gasification & combustion

Loose Oxygen: Become fossil fuels

Carbonization / Pyrolysis: Create charcoal & liberate gases

Biomolecules C + H + O Carbohydrates, Sugars, Cellulose, Lignin, & much more in living and dead biomass.

Add Oxygen: Decay

From: http://www.techtp.com/Torrefaction%20for%20High%20Quality%20Wood%20Pellets.pdf, page 7 of 36

How does wood burn?

• Wood, consists of hemicellulose, cellulose and lignin– Hemicellulose gasifies at 250 – 300C

– Cellulose splits into char and volatiles between 300C and 450C

– Lignin splits into char and volatiles between 300C and 750C

– Volatilization cools the remaining solid, but the gases burn and generate radiant heat (yellow to blue light)

– Eventually, oxygen can react with the remaining char to make CO2, H2O and ash, plus more heat (red light)

• Putting it all together, we can summarize this in the next two slides that are easier to understand:

D

drying (A)

ExtensiveDevolatilisation

and

carbonisation(E)

Limiteddevolatilisation

andcarbonisation (D)

depolymerisationand

recondensation(C)

A

E

D

C

E

A

D

C

glass transition/softening (B)

Hemicellulose Lignin Cellulose

100

150

200

250

300

Tem

pera

ture

(°C

)

Hemicellulose Lignin Cellulose100

150

200

250

300

Tem

pera

ture

(°C

)

TO

RR

EF

AC

TIO

N

Pyrolysis & Carbonization Reactions of Wood Below 288 C = Torrefied Wood Above 325 C = Biochar

The combustion flame (“C”) burns gases and provides heat to sustain pyrolysis (“P”). Ash is held in the charcoal until “G” (char-gasification) releases it. When “C” goes out, visible smoke shows condensing gases.

A match shows the simple production of charcoal

• the first synthetic material produced by man.• used to draw on the walls of caves, and • used to transport fire (embers) to new locations.• later used for smelting tin to make bronze tools.• easier to do than any of the coal – oil – gas

options:– Converting wood to charcoal is done by heating in an

atmosphere of limited oxygen.– Known as “Pryolysis” or “Carbonization”, we do it

every time we make a fire with wood.– And Mother Nature’s forest fires predate Smoky the

Bear ……

Making charcoal

57% of carbon 33% of carbon

0% + 6% + 4% of carbon

(35 wt %) (40 wt %) (25 wt %)

Charcoal retains ~ 20% of the weight and 30% of the energy of the biomass, so ~70% of the energy is released as usable vapors.

Created by photosynthesis using solar energy + CO2 + H2O

Chemical changes as wood becomes biochar:

MODIFIED ULIMATE ANALYSES OF CHARS

0%

20%

40%

60%

80%

100%W

eig

ht

perc

en

t o

f d

ry s

am

ple

Resident Carbon Resident H & O Resident Nitrogen Mobile Carbon

Mobile H & O Mobile Nitrogen Ash (acid soluble) Ash (non-soluble)

Source: McLaughlin, Anderson, Shields & Reed (2009). All Biochars Are Not Created Equal…terrapreta.bioenergylists.org

Conclusion # 2:

• Charcoal is made by the thermal transformation of biological matter, mainly carbohydrates.

• Plant biomass seems to create the best biochar – both woods and grasses.

• All biochars are not equal – both starting biomass and carbonization conditions influence the final biochar properties.

Basic Forms andTransformations of Carbon:

Elemental Carbon C (solid)

Activated charcoal

Regular charcoal

Graphite

Carbon black (soot)

Coke (from coal)

Oxide gases C + O

CO & CO2

Hydrocarbons C + H

Coal, oil, gases

Add H2O and

photosynthesis by plants

Add Oxygen: Gasification & combustion

Loose Oxygen: Become fossil fuels

Carbonization / Pyrolysis: Create charcoal & liberate gases

Biomolecules C + H + O Carbohydrates, Sugars, Cellulose, Lignin, & much more in living and dead biomass.

Add Oxygen: Decay

Timelines for Carbon Transformations & Permanence

CO2

Biomass (living and dead)

Natural short-term cycle of growth and decay (including biomass burning) is Carbon Neutral: C=

Fossil Fuels Biocarbon

Biochar in Soils Hundreds or thousands of years as long-term carbon sequestration: C-

100 million years ( C- ) 100 minutes ( C- )

Optional human activity, creating Terra Preta

Burn it. Burn it.

200+ years of fossil fuel consumption is Carbon Positive: C+

Storing carbon is Carbon Negative: C-

Timelines for Carbon Transformations & Permanence

CO2

Biomass (living and dead)

Natural short-term cycle of growth and decay (including biomass burning) is Carbon Neutral: C=

Fossil Fuels Biocarbon

Biochar in Soils Hundreds or thousands of years as long-term carbon sequestration:

100 million years ( C- ) 100 minutes ( C- )

Optional human activity, creating Terra Preta!!!

Burn it. Burn it.

200+ years of fossil fuel consumption is Carbon Positive:

C+ in enormous proportions!!!

Storing carbon is Carbon Negative: C-

C-

Ice age Ice age Ice age Ice age

285 in 1950

> 380 in 2010

< 300 in 1950

Most recent Ice Age

Shows ONLY 400,000 years. “Civilization” is less than 10,000 years old.

 

Global Temperature and Atmospheric CO2 over Geologic Time 

Late Carboniferous to Early Permian time (315 mya -- 270 mya) is the only time period in the last 600 million years when both atmospheric CO2 and temperatures were as low as they are today (Quaternary Period ). Temperature after C.R. Scotese http://www.scotese.com/climate.htm CO2 after R.A. Berner, 2001 (GEOCARB III)           

Source: http://www.geocraft.com/WVFossils/Carboniferous_climate.html

Today

Conclusion # 3:• Global warming can be debated, but the increase in

atmospheric CO2 levels is clearly measured and due to human activities.

• The Earth is very capable of existing with much higher CO2 levels, but our current human society probably could not.

• The only current reasonable method for human action to remove significant amounts of atmospheric CO2 is through biochar for carbon sequestration.

• And Conclusion # 1 states that Biochar is being shown to improve poor soils, so put char into soils!

Potential Sources of BiocharChart of Potential Sources of Biochar

Source: McLaughlin, Anderson, Shields & Reed (2009). All Biochars Are Not Created Equal…terrapreta.bioenergylists.org

Type => Issue

Incidental Traditional Gasifier Other Modern Industrial Processes

Applica-tion Fire

ResidualLump Charcoal

Biomass to Energy

By or Co-product

Sole product

Description(Highly general-ized)

FireplaceForest fireIncineration

Primitive kilns

Modern kilns

DowndraftUpdraftTop-Lit UpDraft

(TLUD)

Traditional retortSpecialized retortFast Pyrolysis

Biocarbon for energyBiochar for soilBio-Gas & Bio-Oil

Oxygen? Oxic - Uncontrolled Oxic = limited oxygen andAnoxic = no oxygen

Oxic Anoxic (usually) Anoxic and Oxic

Commercial for biochar?

No. Basically destructive.

Yes. Established product – for cooking

Biochar is NOT the primary objective.

Initial efforts & biochar is NOT the primary goal

Initial efforts

End of the Beginning about Biochar Basics• Further discussions can cover issues of:

– Production of biochar, including cook stoves.– Application of biochar.– Impact of biochar on plants and soil microbes.

Or is this the Beginning of the End?• With the rising CO2 level, living conditions of most

of humanity will be affected, and current cultural structure and political stability are unlikely to continue for another 100 years.

• Issues of atmospheric CO2 concentrations will not be resolved without conscious and significant actions by all the fuel-intense nations of the World – and actions on the ground everywhere.