Researchers find renewable energy leftovers could fertilize, cut carbon emissions

September 30, 2010 by Stu Hutson

( -- For hundreds of years, farmers in Brazil's Amazon Basin have hunted through dense jungles for what is called "terra preta" — mysterious plots of super-fertile black soil amid otherwise nutrient-stripped earth.

In recent decades, researchers have discovered that the rich properties of terra preta stem from the carbon-heavy leftovers of ancient cooking sites. Now, University of Florida researchers have found we can make our own version of the soil’s potent component, a form of charcoal dubbed biochar, from the remnants of production.

“This could possibly improve the viability of certain biofuels by giving a valuable — both economically and environmentally - byproduct from material that would otherwise just be a disposal problem,” said Bin Gao, an assistant professor of agricultural and at UF’s Institute of Food and Agricultural Sciences.

For example, a renewable form of natural gas can be produced by “digesting” organic material with the help of added bacteria. As they report in the November issue of the journal Bioresource Technology, Gao and a team from UF found that, using inedible portions of sugar cane as , the sludge material left over from this process can then be turned into useful forms of biochar.

The biochar is created through a process called flow pyrolysis, in which plant matter is broken down by exposure to temperatures up to 650 degrees Fahrenheit in a container without much oxygen. This means the carbon-heavy components of the material can’t burn, but are freed up in the blackened leftovers.

Whereas the leftovers from the production would normally need to be treated and disposed of as waste material, biochar can instead be used to augment infertile soil by absorbing pollutants, leveling acidity, improving water retention and reducing the leaching of nutrients.
Biochar has another important property — it can be used to sequester carbon and thus reduce emissions that contribute to the greenhouse effect.

“When you add biochar to the soil, it’s likely that as much as 90 percent of that carbon is still going to be in that soil a hundred years from now if left undisturbed,” said Andrew Zimmerman, UF assistant professor of geological sciences and co-author of the study.
Some studies have indicated that converting all agricultural waste biomass to biochar could reduce carbon emissions by as much as 12 percent, Zimmerman said.

Biochar production can be integrated with other methods of producing biofuels. But more study is needed to understand how to produce biochar suitable for agricultural use, the researchers say.

Explore further: From the ancient Amazonian Indians: A modern weapon against global warming

Related Stories

Biochar: turning waste into wealth

June 10, 2009

As all gardeners know, manure helps the flowers grow. But that manure also gives off greenhouse gases, contributing to global climate change.

Is biochar the answer for ag?

August 2, 2010

Scientists demonstrate that biochar, a type charcoal applied to soils in order to capture and store carbon, can reduce emissions of nitrous oxide, a potent greenhouse gas, and inorganic nitrogen runoff from agriculture settings. ...

Charcoal takes some heat off global warming

August 10, 2010

As much as 12 percent of the world’s human-caused greenhouse gas emissions could be sustainably offset by producing biochar, a charcoal-like substance made from plants and other organic materials. That’s more than what ...

Recommended for you

Scientists capture Earth's 'hum' on ocean floor

December 7, 2017

Scientists have long known earthquakes can cause the Earth to vibrate for extended periods of time. However, in 1998 a research team found the Earth also constantly generates a low-frequency vibrational signal in the absence ...

Birth of a storm in the Arabian Sea validates climate model

December 6, 2017

Researchers from Princeton University and the National Oceanic and Atmospheric Administration (NOAA) report in the journal Nature Climate Change that extreme cyclones that formed in the Arabian Sea for the first time in 2014 ...


Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (4) Oct 02, 2010
Sustainable biochar to mitigate global climate change

Not talked about in this otherwise comprehensive study are the climate and whole ecological implications of new , higher value, applications of chars.

the in situ remediation of a vast variety of toxic agents in soils and sediments.

Dr. Lima's work; Specialized Characterization Methods for Biochar at USDA;
The Ultimate Trash To Treasure, Research Turns Poultry Waste into Toxin-grabbing Char
the uses as a feed ration for livestock to reduce GHG emissions and increase disease resistance.

Recent work by C. Steiner showing a 52% reduction of NH3 loss when char is used as a composting accelerator. This will have profound value added consequences for the commercial composting industy
1 / 5 (4) Oct 12, 2010
Agriculture allowed our cultural accent and Agriculture will now prevent our descent.

Wise Land management; Organic farming and afforestation can build back our soil carbon,

Biochar allows the soil food web to build much more recalcitrant organic carbon, ( living biomass & Glomalins) in addition to the carbon in the biochar.

Every 1 ton of Biomass yields 1/3 ton Charcoal for soil Sequestration (= to 1 Ton CO2e) + Bio-Gas & Bio-oil fuels = to 1MWh exported electricity, so is a totally virtuous, carbon negative energy cycle.

Biochar viewed as soil Infrastructure; The old saw;
"Feed the Soil Not the Plants" becomes;
"Feed, Cloth and House the Soil, utilities included !".
Free Carbon Condominiums with carboxyl group fats in the pantry and hydroxyl alcohol in the mini bar.
Build it and the Wee-Beasties will come.
Microbes like to sit down when they eat.
By setting this table we expand husbandry to whole new orders & Kingdoms of life.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.