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Turning waste into energy is not a new idea. Denmark regularly transforms tons of household garbage into heat and power, while two dozen New York farms cook cow manure in anaerobic digesters, reducing farm waste and producing biogas.

Now, thanks to a newly installed pyrolysis unit 

Largest Biochar Facility in U.S. Opens at Cornell

April 12, 2016

20160413-Lehmann-Kiln-600x298.jpg

Turning waste into energy is not a new idea. Denmark regularly transforms tons of household garbage into heat and power, while two dozen New York farms cook cow manure in anaerobic digesters, reducing farm waste and producing biogas.

Now, thanks to a newly installed pyrolysis unit that is the largest of its kind in the nation, Cornell researchers will explore another trash-to-treasure process, one that holds potential not just for energy production, but for the soil-enriching substance left over. More commonly known as “biochar,” this solid, charcoal-like material is formed by heating and decomposing bio­mass in the absence of oxygen in a process known as slow pyrolysis.

Soil chemist Johannes Lehmann, a world expert on biochar, has been studying its soil-enhancing properties and carbon storage capacity for more than a decade. Recently, there has been a surge of interest in building healthy, rich soil as the world grapples simultaneously with climate change and feeding an expanding population. Soil carbon sequestration is one of only a few promising strategies that could be applied at large scales without costing a fortune. A new Nature article by Cornell researchers describes the technology and its potential.

Though biochar is not a fertilizer, when applied to soil, it boosts fertility by helping retain water when it’s dry, drain water when it’s wet, and keep nutrients in the soils. Relatively unknown a decade ago, today biochar can be purchased online and in some stores, although few large-scale agricultural producers have embraced it, partly because of a lack of large-scale testing and concerns about product quality and consistency.

Biochar isn’t the only farming practice that can enrich soil and sequester carbon. Adding other organic matter such as compost and decreasing tillage are two others. But in the search for solutions that are good for crops and good for the environment, biochar is coming of age at a time when governments are looking for a variety of complementary ways to create local renewable energy, cut emissions, and boost crop production.

All of which means the start-up of the new pyrolysis kiln installed in Leland greenhouse comes at an opportune time. The facility can convert up to 50 kilos of waste an hour—more than 100 times the capacity of most university research units—allowing for rapid testing of different inputs. Cornell faculty Elizabeth Fisher, Lars Angenent, and Max Zhang will work with the gas stream to create fuel, David Lee and Perrine Pepiot will model the utility’s economic and energy performance, while Lehmann will measure the quality of the biochar.

“We will try anything with a disposal issue, crop residue, food scraps, dairy manure, even Ithaca wastewater—anything that constitutes a disposal risk or has disposal costs that we can conceivably convert into a safe and effective soil amendment,” says Lehmann.

The research pyrolysis kiln was made possible by a $5 million gift to the Atkinson Center for a Sustainable Future from philanthropist Yossie Hollander, who is interested in the test facility’s potential to help small farming communities in developing countries, where small-scale pyrolysis could meet local energy needs while producing a soil enhancer that would make costly fertilizers more effective in highly weathered soil.

The new kiln will also allow Lehmann and researcher Dawit Solomon to conduct further tests with bonechar, a phosphorous-rich product that results when discarded animal bones are put through a slow pyrolysis process. The team has already successfully created a viable product in Ethiopia, where animal bones are one of the only indigenous sources of phosphorus, a necessary ingredient for healthy crops. Most of the country’s 80 million farmers cultivate small agricultural plots and after years of overuse, soil is acidic and depleted.Working with economist Garrick Blalock and supported in part by ACSF’s CARE-Cornell partnership, the team devised a farmer-friendly product, Abyssinia phosphorus fertilizer, that more than doubled yields compared to unfertilized soils. Late last year, the consortium produced the first bags of phosphorus pellets—at two-thirds of the cost of commercially available products.

Lehmann says pyrolysis and biochar are not a magic bullet that will completely fix poor soils or slow the pace of climate change. But pyrolysis could be an important part of a portfolio of technologies in a world where one-size-fits-all solutions won’t work, in the same way that solar is viable in some areas, while wind is better in others.

The more options there are in the world’s problem-solving basket, the better, Lehmann says. “We can’t afford not to put it into that basket and examine where it could be used and when it could be used.”