“Biochar, soils and sustainable agriculture”

Cambridge Energy Forum

22 April 2010

Dr Bruce Tofieldb.tofield@uea.ac.uk

Biochar in theEast of England

Potential major benefit for

• soil quality

• agricultural productivity

• nutrient use

• greenhouse gas reduction

Many uncertainties and unknowns

Pathway to commercialisation uncertain

InCrops leading activity for East of England Soil Strategy

Part of 2020 Vision for EE Food and Farming Sector?

Biochar Production

Temp & Duration

Solid

(Biochar)

Liquid (Bio oil)

Gas (Syn Gas)

Slow Pyrolysis

~500C

Days

35% 30% 35%

Fast Pyrolysis

~500C

Seconds

12% 75% 13%

Gasification >800C

Hours

10% 5% 85%

CHP GasificationSlow Pyrolysis (retort) Slow pyrolysis (kiln)

Fast Pyrolysis

Biochar Production

Eprida: Hydrogen and Char Fertiliser via Pyrolysis

Dynomotive:

Bio oil via

Fast

Pyrolysis

BEST Energies: Biochar via Slow Pyrolysis

University of Hawaii:

Flash Carboniser (Fast Pyrolysis)

Biochar does notdegrade in soils

•Compost and other organic material in soils is valuable but mineralises (converts to CO2) in just a few years.

•Biochar will remain essentially unchanged for hundreds or even thousands of years – carbon sequestration really is possible

Charcoal occursnaturally in soils

•Up to 35 per cent of SOC in some US soils is charcoal from natural processes (Skjemstad et al, 2002)

•Natural charcoal in the US midwest prairie soils, a result of ten thousand years of prairie fires, may play a role in these soils’ high and sustained fertility

•Our results provide clear evidence that immediately after wildfire fresh charcoal can have important effects in Boreal forest ecosystems dominated by ericaceous dwarf shrubs, and this is likely to provide a major contribution to the rejuvenating effects of wildfire on forest ecosystems.(Wardle et al, 1998)

(Skjemstad et al)

80 per cent of Africans rely on biomassfor energy

Charcoal market in Khartoum, Sudan

Uganda has lost half

its forest cover in

the last ten years;

97 per cent of the

population uses

charcoal and

firewood for

cooking; charcoal

production creates

20,000 jobs

‘Slash and burn’ to‘slash and char’

Over 2 billion people rely on traditional biomass for heating and cooking using inefficient and dirty stoves or open fires.

Improved stoves that are clean and can also make charcoal could improve health, reduce mortality and assist in agricultural transformation

Third generation cooking stove:Low pollution, production of biochar

(Flanagan and Joseph)

Energy from Biomass

Thetford chicken litter plant

420,000 tonnes pa, 38.5MWe

Proposed Thetford waste

wood power station,

300,000 tonnes pa,

40MWe

Bioenergy 5% oftotal UK energyby 2020?

•All present-day

resources will be

needed to meet 2020

renewable energy

targets.

•Current technology

is combustion for

electricity or heat.

•CHP gives twice the

carbon savings of

electricity onlyAnnex B: UK Biomass Strategy, 2007

Electricity only frombiomass a massiveresource waste

“Biomass plants generating only electricity, a number of which are currently in

development, cannot have a long-term future in the UK’s energy mix as

they are not able to produce sufficiently low carbon energy.”

“The infrastructure being developed in the UK now will form a major

component of the country’s generating capacity in 2030.”

Biomass: Carbon Sink or Carbon Sinner?Environment Agency, April 2009

UK Bioenergy StrategyRenewable EnergyBiochar not mentioned

CCS longer termand essential

CoalCoal is responsible for 70 per cent of 185 Mt CO2 from electricity generation, i.e. 130 Mt CO2130 Mt CO2. CCSCCS could in principle decarbonise 85%decarbonise 85% of these emissions – about 110 Mt110 Mt. Essential by 2050 – nothing possible before 2020nothing possible before 2020.

Biochar vs CCS

• CCS is essential to decarbonise the UK’s electricity supply

• CCS reduces CO2 emissions from fossil fuels it does not eliminate them

• Biochar removes CO2 emissions from the atmosphere

• In the UK biochar might yield a few million tonnes CO2 saving with current biomass sources – CCS needs to aim for over 100 m tonnes

• Using gasifier technology, biochar can be produced today – few barriers to entry – major bioenergy benefit for the Region – if heat/CHP as well as electricity

• Biochar provides potential major benefits for agriculture and soils in addition to carbon sequestration

Biochar ingeoengineering

“Biochar has the potential to sequester almost

400 billion tonnes of carbon by 2100 and to

lower atmospheric carbon dioxide

concentrations by 37 parts per million.”

Professor Tim Lenton, UEA

UEA’s biomass gasifier1.4MWe, 2MWh

The biomass gasifier at UEA will be typically

eighty per cent efficient for the heat will be used

Reduces UEA carbon footprint by 35 per cent

UEA’s biomass gasifier

Also 300 tonnes pa biochar

UEA’s biomass gasifier

Glo

bal

gh

g

emis

sio

ns

Stern, Fig B, p199Data for 2000

Land use change and agriculture emissions are over two times total transport emissions

Greenhouse gasesemitted by

agricultural activityGHG Lifetime GWP

20 yrsGWP

100 yrs

GWP 500 yrs

CO2 200yrs 1 1 1

CH4 12yrs 62 21 7

N2O 114yrs 275 310 156Carbon dioxide, the most common GHG is the reference (i.e. GWP =1) for GWP of all GHG’s

Carbon Accounting included GHG’s given in tonnes of carbon dioxide equivalents or tCO2 equivalents

Care: sometimes as tCe (CO2 = C x 44/12)

GHG’s fromUK Agriculture

• ‘Agriculture’ is responsible for ~0.7% of UK GDP.

• But 7-8% of UK GHG’s

• ~26m tonnes CO2e of nitrous oxide

• ~18m tonnes CO2e of methane

• ~5m tonnes (net) of carbon dioxide

• 37% of UK methane (landfill is 40%)

• 67% of UK nitrous oxide emissions

• CO2 emissions from gasoil, electricity etc is about 1% of UK CO2

(of which gasoil – red diesel – is about 60%)

N2O26.4

CO2

5.3

CH4

18.3

NAIE/DEFRA 2004/5

UK Nitrous oxide

agricultural sources

• 28% synthetic fertiliser application

• 27% leaching of fertiliser nitrogen and animal manures to ground and surface water

• 14% wastes from grazing animals

• 14% ploughing in crop residues

• 9% manure used as fertiliser

•Essentially, half N2O, 2% total UK ghg emissions, arises

from artificial fertiliser•The manufacture of the fertiliser will double this amount

Carbon in soils

From Bradley et al, 2005

Carbon in UK soils

Soils provide multipleecosystem services

Soil degradationby agriculture

“Our soils have

degraded over the

last 200 years due

to intensive

agriculture and

industrial pollution.”

Safeguarding our

Soils: A Strategy for

England, Defra,

September 2009

From Guo and Gifford, 2002

How biochar can help?

Annals of Applied Biology, 37 (1950) 159-168

Left: a nutrient poor oxisol; Right: an oxisol transformed into fertile terra preta (Glaser et al, Naturwiss., 2001)

Amazonian Dark EarthsADE

Many small-scale studiesin poor soils

Char added Normal soil

Picture from Black is the new green, Nature, 442, 624-626, 2006

Charcoal use in Japan

“Although the

reason is not

clear, it is

interesting that

most symbiotic

microorganisms

prefer to

propagate in or

around charcoal

and most plant

roots respond well

to charcoal.”

“Utilizing charcoals in agriculture and

forestry must be meaningful not only to get

high productivity or crops and timber but

also to reduce the carbon dioxide content

in the atmosphere.”

Utilization of Symbiotic Microorganisms and Charcoal for Desert Greening

Makoto Ogawa, Green Age (1998) 14, 5-11

AMF, promote nutrient release, promote SOC, promote plant growth?

Soil aggregation and carbon

sequestration are tightly correlated with

the abundance of arbuscular

mycorrhizal fungi: results from long-

term field experiments

Gail W. T. Wilson, Charles W. Rice,

Matthias C. Rillig, Adam Springer, and

David C. Hartnett

Ecology Letters (2009) 12 (5) 452-461

AMF form symbiotic associations with

over 80 per cent of land plants and

promote beneficial soil structure and

SOC formation

AMF symbiant with over 80% plants

“The diversity of arbuscular mycorrhizal fungi [AMF] is strikingly low in arable sites compared with a woodland” (Ploughing up the wood-wide web?, Nature 1998)

Finlay, Mycologist, 18 (2004)

Benefits of biochar

“Trials of agrichar - a product hailed as a saviour of Australia’s carbon-

depleted soils and the environment - have doubled and, in one case, have doubled and, in one case,

tripled crop growthtripled crop growth when applied at the rate of 10 tonnes per hectare10 tonnes per hectare …

For the wheat, agrichar alone was about as beneficial for yields as using as beneficial for yields as using

nitrogen fertiliser onlynitrogen fertiliser only ... Soil biology improved, the need for added need for added

fertiliser reducedfertiliser reduced and water holding capacity was raisedwater holding capacity was raised ... The trials also

measured gases given off from the soils and found significantly lowersignificantly lower

emissionsemissions of carbon dioxide and nitrous oxidenitrous oxide…”

http://www.dpi.nsw.gov.au/research/updates/issues/may-2007/soils-offer-new-hope

Biochar may

• Improve soil structure

• Improve water retention

• Reduce nutrient requirement

• Enhance impact of AMF

• Reduce nitrous oxide emissions

• Help restore soil organic carbon

But many unknowns

• Effect of production method and temperature

• Effect of source biomass

• Effect of soil type

• Lifetime in soil

• Mechanism of impact on soil biota

• Acceleration of microbial activity?

Key steps

• Trials in pots and field

• Study impact of production method and source material

• Develop routes to commercial production (small, medium, large-scale)

• Develop cost effective SOC monitoring

Can we make this region a leader in both sustainable bioenergy and sustainable agriculture via biochar?