BioChar: RVA’s Green Project

Our Climate Change Activist program focuses on making of St. Vincent a Climate Compliant Country. This entails working shoulder to shoulder with Vincentians to build sustainable food and energy production systems; as well as leading an overall sustainable lifestyle. Consequently, the March Team for the program is working on a BioChar project that seeks to introduce a sustainable production of this resource in St. Vincent.

As you will see, the production of BioChar requires a kiln. Our team is currently in the stage of building the pilot at the Academy; however, the plan is to build as many as 100 kilns throughout St. Vincent by 2017, thus instilling a BioChar culture among Vincentians.

But what exactly is BioChar? How and most importantly, why should we use it? We answer all these questions below.

WHAT IS BIOCHAR?

BioChar is a type of charcoal which comes from biomass (e.g. plant matter and agricultural waste, etc.). Its primary use lies in soil improvement, which is vital in agribusiness because it protects plants against some foliar and soil-borne diseases. Once created, BioChar can endure in soils for thousands of years; consequently boosting food security, increasing soil biodiversity and discouraging deforestation.

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Photo Credit: Wikipedia

As other types of charcoal, BioChar is created by heating the biomass in a low-oxygen —or hypoxic— environment. The ensuing chemical reaction is called pyrolysis and is self-sustaining once it has begun. It does not require any external energy imput and has an efficiency of 70%. This means that 70% of the biomass that enters the reaction exits it as charcoal.

The end result is a “fine-grained, highly porous charcoal that helps soils retain nutrients and water” (Biochar International, W/D)

TERRA PRETA

BioChar is not something we drew from our sleeves.

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Terra preta is rich in charcoal, manure and bone. As a result, it can work as an excellent soil enhancer – Photo Credit: Wikipedia

This resource is a common byproduct of vegetation fires. Moreover, man-made BioChar is an ancient practice that dates back 2,000 years. In fact, its current use as a soil enhancer comes from intensive studies of the Amazonian terra preta de índio (“black soil of the Indian” in Portuguese); which is the result of “adding a mixture of charcoal, bone and manure to the relatively infertile Amazonian soil” (Wikipedia, W/D). Terra Preta is a very dark and fertile soil, rich in charcoal, which remains in the earth for milleniums and retains minerals and nutrients.

Anthropogenic Terra Preta has been in the Amazonian Basin since at least 450 BCE and regerates itself at the rate of 1 centimeter per year.

BENEFITS OF BIOCHAR

[Tweet “Most additions of BioChar to soil reduce NO2 emissions by up to 80% and eliminate CH4 emissions.”]

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Benefits of BioChar – Photo Credit: BioChar International
  • Soil fertility: As mentioned by BioChar International, this resource can improve soil fertility and stimulate plant growth. The latter has a positive feedback effect, as it consumes more carbon dioxide through photosynthesis.
  • Reduced fertilizer inputs: The porous nature of BioChar is very effective at retaining water and water-soluble nutrients.  Furthermore, BioChar leads to better yields for plants that require high potash and basic soil. Finally, this resource creates a higher crop uptake of nutrients and provides greater soil availability of nutrients.
  • Reduced nitrous oxide and methane emissions: Most additions of BioChar to soil reduce NO2 emissions by up to 80% and eliminate CH4 emissions. Both of these chemical compounds have greater heat-storing capacity than carbon dioxide.
  • Enhanced soil microbial life: The use of BioChar reduces leaching of E-coli through sandy soils. It also induces plant systemic responses to foliar fungal diseases under certain circumstances. Finally, crops planted in a BioChar soil exhibit the same response with soil-borne pathogens.
  • Slash-and-char: Using this farming technique in sustitution of the more traditional slash-and-burn can reduce carbon dioxide emissions by 47%; as well as increase crop yields.
  • Reduced emissions from feedstocks
  • Energy generation: Controlling the temperatures during the pyrolysis process can result in liquid and gaseous fuels. Sustainable production of these fuels and of solid BioChar can potentially offset the use of carbon positive fossil fuels. Furthermore, using pyrolisis does not require significant infrastructure changes. The same is not true for processing biomass to obtain ethanol.
  • Reduced waste outputs
  • Reduced production time: The whole pyrolysis process takes only four hours. In contrast, traditional ways of producing charcoal can take up to 10 days.

WHY ARE WE INTRODUCING BIOCHAR IN SAINT VINCENT AND THE GRENADINES?

As is the case with people in other developing countries, Vincentians still use coal-powered stoves for cooking. In fact, Saint Vincent produces and consumes charcoal every day; with recent statistics showing an increment in both production and consumption of this resource since at least 2003.

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Saint Vincent and the Grenadines charcoal production and consumption rates – Photo Credit: Knoema

This is dangerous to the country’s present and future plans.

Saint Vincent and the Grenadines has been making progress towards becoming a Climate Compliant Country and could potentially reduce its greenhouse gas emissions in 22% by 2025. At present, nearly 70% of the national carbon emissions come from the energy sector, which englobes energy generation and transportation. Futhermore, the energy generation sector covers  the hydropower industry and all non-electrical energy supply, which, you guessed it, includes charcoal (UNFCCC, 2015)

In a business-as-usual environment, Vincentians produce charcoal through a lengthy and polluting method. They do not employ kilns and the entire method lasts ten days and releases a considerable amount of carbon into the atmosphere. Furthermore, only 30% of the biomass turns into charcoal; as opposed to the 70% conversion rate of BioChar kilns.

What is more, BioChar systems can be carbon negative.
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Avoided emissions of BioChar vs Biomass over a century – Photo Credit: BioChar International

What does this mean?

Let’s see. Once dead, plants release the carbon they absorbed through photosynthesis in processes like decomposition. However, if we use these plants as biomass for the generation of BioChar, the chemical process traps the carbon in the stable structure of the ending product. Afterwards, if we use BioChar as a soil enhancer, we are trapping this carbon in the ground for thousands of years. Bottom line, we are contributing to a net reduction in carbon emissions.

According to Woolf et al (2010), sustained use of BioChar could contribute to a 12% reduction in anthropogenic GHG emissions per year. This means that over the course of 100 years, the amount of avoided emissions would amount to 106 metric tons of CO2 equivalents.

For comparison, the graphic below shows the avoided emissions coming from sustainable BioChar production or biomass combustion over 100 years. All figures are relative to current consumption rates of biomass. There are three prospect scenarios:

  • MSTP: Maximum sustainable technical potential, which is shown in red.
  • Medium (blue)
  • Black (Low)

These entail annual avoided emissions as well as cumulative avoided emissions over 100 years. You’ll see that BioChar is undisputably the winner in both instances.

IS THERE A DOWN-SIDE TO BIOCHAR PRODUCTION?

Yes. The starting price for a BioChar kiln is of 600 USD, which is rather expensive for the average farmer. However, the initial investment is more than paid off by the BioChar production. As we mentioned above, this resource is extremely useful in soil improvement, and can even work as coal for the kitchen. Finally, farmers can sell their BioChar surplus in the local markets for a profit.

 

 

 

BioChar: RVA’s Green Project

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