From Kilns to Kitchens: Unlocking Biochar’s Potential in Italy

In the world of Italian pizza, the choice between Neapolitan, Roman and Sicilian is steeped in tradition and appreciation for the cooking process. Each style has its own unique recipe to create the final product of a culinary delight. The method of crafting biochar, with its different biomass choices and performance characteristics, is surprisingly similar.

Praveen Kolar, a professor in the Department of Biological and Agricultural Engineering at NC State University and self-proclaimed foodie, recently spent three months exploring both of these worlds as a Fulbright Scholar at the University of Bologna in Italy. While abroad, he spent time sampling Italian cuisine and working on his research project, which focuses on transforming rice husk into biochar (a black carbon-rich material formed when biomass is heated without oxygen) to power capacitors in energy storage devices.  

The Ingredients: Choosing the Best Biomass

As any good chef would know, you must start your process by choosing your ingredients. To create quality biochar, Kolar began by testing different types of biomass. Biochar can be made from a range of carbon-rich materials. 

For Kolar’s uses, he wanted his material to have a large surface area and be porous or permeable. “I ran so many samples there, not only rice husk. I actually tried peanut husk, coffee chaff, commercial biochar — I mean everything,” he says. 

Kolar plans to use rice husks in his research, not only because it performs very well, but also because it is a common agricultural byproduct around the world. Using rice husks to make biochar would give farmers the opportunity to sell it as a value-added product. 

The Oven: The Power of Pyrolysis

Once the ingredients are put together, it is time to put it in the oven. The degree of heat you set your oven to depends on which style of pizza you are making. Formulating biochar also requires specific cooking conditions. 

Instead of an oven, Kolar uses kilns absent of oxygen to heat the biomass and unlock its potential to create energy. A kiln heats biomass at extreme temperatures so that a process called pyrolysis can occur. This process destroys gases and other materials in the biomass, leaving only the black carbon-rich biochar. Once the biochar is made, researchers can use it as fuel, a catalyst or several other applications depending on the desired characteristics. The exact temperature of the kiln determines the finished product, much like an oven setting. 

Digging In: A High-Power Capacitor

When the pizza is ready, it can be served on the go, family style or buffet style, depending on the consumer. In Kolar’s research, the biochar goes on to be used as energy in a capacitor — a kind of battery that provides short bursts of high power. 

Biochar is typically used to power certain types of batteries that require a small amount of energy for a long period of time. Kolar has other ideas about how to utilize this energy in different ways. 

“The battery has its own place, but I cannot use a battery to do activities which require a lot of energy,” Kolar says. “Imagine we are driving a car, and then we want to pass somebody. For those 20 seconds, we have to go really fast to pass the car, and then we go back to our normal speed. So for those few seconds, you need a lot of energy. That’s how a capacitor uses energy.”

In North Carolina, “we have waste that we could repurpose, reimagine,” he says. Using biochar to power capacitors could help make products like lights that power camera flashes, defibrillators and everyday devices more sustainable.

A place at the Table

Unlocking the potential for biochar could create more places at the table for this resource. “Biochar is perhaps one of the better ways to create products that not only help the environment, but also provide a new revenue stream for farmers,” Kolar says.

Now that Kolar is back from Bologna, he is sorting his data and reminiscing on all the culinary experiences he had between lab sessions.

“The pizza is not the same in Naples as it is in Rome or Bologna,” he says.

Just like in the world of Italian pizza, creating biochar requires you to combine your ingredients, set fire to them, and decide which is best. 

This post was originally published in College of Agriculture and Life Sciences News.