Transcript Bruce Tofield Composite Intro, June 29 09

Dr Bruce Tofield
[email protected]
“Biochar, soils and sustainable
agriculture”
Cambridge Energy Forum
22 April 2010
Biochar in the
East 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
CHP Gasification
Temp &
Duration
Slow
Pyrolysis
~500C
Fast
Pyrolysis
~500C
Gasification
>800C
Slow Pyrolysis (retort)
Solid
Liquid
(Bio oil)
Gas
(Syn Gas)
35%
30%
35%
12%
75%
13%
10%
5%
85%
(Biochar)
Slow pyrolysis (kiln)
Days
Seconds
Hours
Fast Pyrolysis
Biochar Production
Dynomotive:
Bio oil via
Fast
Pyrolysis
Eprida: Hydrogen and Char Fertiliser via Pyrolysis
University of Hawaii:
Flash Carboniser (Fast Pyrolysis)
BEST Energies: Biochar via Slow Pyrolysis
Biochar does not
degrade 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 occurs
naturally in soils
•Up to 35 per cent of SOC in
(Skjemstad et al)
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)
80 per cent of Africans
rely on biomass
for energy
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
Charcoal market in Khartoum, Sudan
‘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% of
total UK energy
by 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 only
Annex B: UK Biomass Strategy, 2007
Electricity only from
biomass a massive
resource 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 Strategy
Renewable Energy
Biochar not mentioned
CCS longer term
and essential
Coal is responsible for 70 per cent of 185 Mt CO2 from electricity generation, i.e.
130 Mt CO2. CCS could in principle decarbonise 85% of these emissions –
about 110 Mt. Essential by 2050 – nothing possible before 2020.
Biochar vs CCS
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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 in
geoengineering
“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 gasifier
1.4MWe, 2MWh
UEA’s biomass
gasifier
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
Also 300 tonnes pa
biochar
UEA’s biomass
gasifier
Global ghg
emissions
Stern, Fig B, p199
Data for 2000
Land use change and agriculture emissions
are over two times total transport emissions
Greenhouse gases
emitted by
agricultural activity
GHG
Lifetime
GWP
20 yrs
CO2
CH4
N2O
200yrs
12yrs
114yrs
1
62
275
GWP
100
yrs
1
21
310
GWP
500
yrs
1
7
156
Carbon 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 from
UK Agriculture
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‘Agriculture’ is responsible for ~0.7% of UK GDP.
But 7-8% of UK GHG’s
~26m tonnes CO2e of nitrous oxide
CH
~18m tonnes CO2e of methane
N2O
26.4
4
18.3
• ~5m tonnes (net) of carbon dioxide
• 37% of UK methane (landfill is 40%)
• 67% of UK nitrous oxide emissions
CO2
5.3
NAIE/DEFRA 2004/5
• CO2 emissions from gasoil, electricity etc is about 1% of UK CO2
(of which gasoil – red diesel – is about 60%)
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 multiple
ecosystem services
Soil degradation
by 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
Amazonian Dark Earths
ADE
Left: a nutrient poor oxisol; Right: an oxisol transformed into fertile terra preta
(Glaser et al, Naturwiss., 2001)
Many small-scale studies
in poor soils
Char added
Normal soil
Picture from Black is the new green, Nature, 442, 624-626, 2006
Charcoal use in Japan
Utilization of Symbiotic Microorganisms and Charcoal for Desert Greening
Makoto Ogawa, Green Age (1998) 14, 5-11
“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.”
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 longterm 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 carbondepleted soils and the environment - have doubled and, in one case,
tripled crop growth when applied at the rate of 10 tonnes per hectare …
For the wheat, agrichar alone was about as beneficial for yields as using
nitrogen fertiliser only ... Soil biology improved, the need for added
fertiliser reduced and water holding capacity was raised ... The trials also
measured gases given off from the soils and found significantly lower
emissions of carbon dioxide and nitrous oxide…”
http://www.dpi.nsw.gov.au/research/updates/issues/may-2007/soils-offer-new-hope
Biochar may
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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
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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
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Trials in pots and field
Study impact of production method and source material
Develop routes to commercial production (small, medium, largescale)
Develop cost effective SOC monitoring
Can we make this region a leader in both sustainable
bioenergy and sustainable agriculture via biochar?