1. The Benefits of Biochar
Donna Udall
Donna.Udall@coventry.ac.uk

2. Some Definitions
The carbon rich product obtained when biomass such as wood,
manure or leaves, is heated in a closed container, with little or no
air (Lehmann and Joseph; 2009).
Charcoal made in modern technology, from sustainable resources and is
used for any purpose that doesn’t result in it breaking down rapidly back
into CO2, like burning it as a fuel (The British Biochar Foundation).
What is Biochar?

3. The Potential Benefits of Biochar
Reduced waste through
waste recovery options
e.g. pyrolysis
Reduced environmental
impact (odour, land use,
burning)
Increases crop yield by improving soil fertility, soil
structure, water-holding capacity, cation exchange
capacity and soil microbial activity.
Locks carbon in the soil
and reduces emissions
of other Greenhouse
Gases
Producing biochar
generates heat, oil and
gases
Climate Change
Mitigation?
A Source of
Renewable Energy?
Improving Soils? Transforming Waste?
Increases efficiency of fertiliser use, decreases nutrient
run-off and binds contaminants.

4. Biochar as Climate Change Mitigation
The Problem…
• Climate change - a significant and lasting change in the statistical distribution
of weather patterns over periods ranging from decades to millions of years.
The Biochar Solution…
Store carbon: away from the atmosphere, in the form of biochar buried in
soils – known as carbon sequestration.
Carbon sequestration: (the process of capture and long-term storage of
atmospheric CO2) only works if two conditions are met;
• Plants have to be grown at the same rate as they are charred
• The product needs to be more stable than the biomass from which it was
formed – biochar is.
Diverting 1% of the annual net plant uptake into biochar would
mitigate almost 10% of current anthropogenic carbon emissions
RESULT

5. Biochar in Transforming Waste
The Problem…
• Crop and animal waste pose a significant environmental burden, polluting
land and water.
The Biochar Solution…
• Through pyrolysis, waste volume can be reduced and the product reused.
Pyrolysis is; the thermal decomposition of organic material under limited
supply of oxygen, at relatively low temperatures (Lehmann and Joseph;
2009).
• Decreasing methane emissions from landfill
• Decreasing industrial energy use & emissions due to recycling &
waste reduction
• Decreasing energy used in long-distance transport of waste
• A saleable environmentally friendly product
RESULT

6. Biochar to Produce Energy
The Problem…
• A worldwide requirement for renewable energy
The Biochar Solution…
• During pyrolysis, gases, oils and heat can be produced and taped off.
However, adding biochar to soil instead of using it as a fuel, does reduce
the energy efficiency of pyrolysis bioenergy – BUT – the emission
reductions associated with biochar additions to soil appear to be greater
than the fossil fuel offset in its use as a fuel (Gaunt & Lehmann, 2008)
Pyrolysis offers either the production of gas, oils or clean heat.
This is needed at a national and local level. For instance,
pyrolysis cooking technology results in lower indoor pollution
by smoke than usual biomass burners.
RESULT

7. The Problem…
In both industrialised and developing countries, soil loss and degradation is
occurring at unprecedented rates (IAASTD, 2008).
The Biochar Solution…
Biochar can influence physical nature of soil systems by changing soil depth,
texture, structure, porosity and consistency through changing the bulk surface
area, pore size distribution, particle size distribution, density and packing
It influences the chemical nature of soils through the presentation of sites for
chemical reactions and an improve cation exchange capacity
It also provides protective habitats for soil microbes, influencing the biological
aspects of soil fertility
Biochar can alter the physical, chemical and biological nature of
soil such that it returns significantly higher yields when applied
with other amendments (e.g. Chan et al. 2007, Downie, A.
2011)
RESULT
Biochar as a Soil Amendment

8. Loamy sand
Sandy Loam
Silt Loam
Loamy sand
Sandy Loam
Silt Loam
Figure 1. WHC of three soils amended with
maize stover biochar at three rates
Figure 2. WHC of three soils amended with sawdust
biochar at three rates
Focus on Water
(Dugan et al. 2010)
The Problem…
Globally, the proportion of Earth's surface in extreme drought is projected to rise from
about 1% today to around 30 % by late this century—if our heat-trapping emissions
continue to rise at high rates (Hennessy et al. 2007).
The Biochar Solution…
So far research has found; biochar addition to boreal agricultural soil increases water
holding capacity by 11% (Karhu et al, 2011). Dugan et al (2010) found WHC was
increased when biochar was applied at all rates compared to zero application.
RESULT

9. Real world
pyrolysis
running
costs
Product
revenue
streams
Cost savings
from re-use
of waste
Farm scale
trials
Biochar cost
analysis
Implications for
land use
Pollution
and
biodiversity
impact
Carbon life
cycle. Carbon
credits
Food
Security
(implications
from land
use
Impact on
farmers –
time,
resources,
economics,
well-being
Impact on rural economy. Employment
opportunities
Research into Biochar Production and Use –
Consequences for Profit, People and Planet
Profit
Planet
People
Drought protection (through
improved soils)
Flood protection
(through improved
soils)
Next Steps . . .

10. Thank you!
• Dr Julia Wright – for suggesting I ‘may’ be interested in
biochar . . .!
• Gemma Forster – Design and Grammar Guru!
• Dr Francis Rayns – for providing the wellies that keep my feet
on the ground
• Dr Lindsey Shutes – for being just generally brilliant
Any questions?
Email me; donna.udall@coventry.ac.uk