michael horton - biochar
Post on 22-Jan-2015
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Michael Horton Biochar!
The potential benefits from Biochar for
Cambodia.. Michael Horton
ConCERT (Connecting Communities, Environment & Responsible Tourism)
Biochar is biomass that’s burned in a low/no oxygen environment (pyrolysis)
Biochar is biomass that’s burned in a low/no oxygen environment (pyrolysis)
So, how can biochar help Cambodia?
1. Source of energy Pyrolysis can occur over a wide range of temperatures
• low temperatures maximises biochar production
So, how can biochar help Cambodia?
1. Source of energy
• high temperatures = gasification
So, how can biochar help Cambodia?
1. Source of energy
So, how can biochar help Cambodia?
1. Source of energy
Gasification can be on a small scale such as gasification stoves for homes:
• burn a wide range of fuel
• burn the gases produced • leave biochar as residue • use 25% of the fuel of an open stove
So, how can biochar help Cambodia?
1. Source of energy
Social/health benefits of gasification stoves:
• reduce labour in collecting fuel • virtually no emissions
• reduce bronchial complaints especially for women & children
So, how can biochar help Cambodia?
1. Source of energy Large scale gasification
So, how can biochar help Cambodia?
1. Source of energy -‐ Large scale gasification
Gas produced is fed into the diesel engine of the rice mill generator, saving between 60 and 80% of the diesel used
The energy from one tonne of rice will process 3 tonnes
Now, what can we do with all that biochar…
So, how can biochar help Cambodia?
2. Soil amendment (conditioner) – Biochar structure varies depending on what it’s made from, but all types are like a honeycomb
Terra Preta • Terra Preta, (dark earth), deep deposits of black and intensely fertile soil in the Amazon rainforest, which is found right alongside some of the poorest soils on earth, oxisols (tropical rain forest soils)
• Deposits are located along rivers and sometimes in areas raised above the floodplain, covering an area about the size of France
• Scientists believe it was created over thousands of years by people who practiced “slash and char” agriculture
Slash and Char agriculture
• 6 feet deep trenches dug and filled with cleared “slash” (biomass)
• soil dug out to create the holes put back on top and whole lot set on fire
• biomass high moisture content and lack of oxygen made fires smoulder for hours, even days
• pyrolysis turned biomass into biochar
Improved soils
• Slash and Char much more efficient at conditioning soil than Slash and Burn – could start growing crops immediately
• honeycomb structure: • retains water and nutrients • reduces run off • encourages beneficial microorganisms to grow
• benefits have lasted between 800 and a few thousand years
Improved soils In common with other locations throughout Cambodia, soils in Siem Reap province, especially north of Route 6, are notoriously poor:
• sandy • lacking in nutrients
Many Cambodians rake up and burn valuable biomass everyday, much of which could fuel gasification stoves with the biochar residue added back to the soil
So, how can biochar help Cambodia?
3. Reduced carbon emissions
So, how can biochar help Cambodia?
3. Reduced carbon emissions
• plants capture CO2 and lock it in their structures (sequestration)
• this is released again when they are burned or decay
• incorporating biochar into the soil locks around 50% of the carbon away for hundreds/thousands of years
So, how can biochar help Cambodia?
3. Reduced carbon emissions
• this has the potential to reduce the build up of CO2 in the atmosphere
• decomposing plant tissue also produces methane (20+ times more powerful greenhouse gas than CO2)
• methane is produced, captured, and used as a fuel in gasification
Worldwide CO2 emissions and climate change have nothing to do with Cambodia? Hmmm……
Michael Horton
Thank You!
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