Biochar: Emerging Carbon Removal Technology

Biochar has the potential to remove 6% of global carbon dioxide emissions annually and can be deployed at scale. Therefore it is expected to play a pivotal role in the concept of circular economy. This charcoal-like substance is produced by pyrolysis of different kinds of biomass feedstock in a controlled process. Professor Mauro Giorcelli, Associated Professor at the Department of Applied Science and Technology (DISAT) at the Politecnico di Torino and board member of the Italian Biochar Association, studies biochar and explores its potential. During his visit to the Elementar headquarters, he provided us with a unique opportunity to delve into the latest advancements in biochar research.

Before turning to biochar as his main research topic, Professor Giorcelli studied carbon materials and composites made from carbon tubes and graphene. As these materials are extremely expensive, Professor Giorcelli started investigating biochar and its properties, a cheap and readily available type of carbon material. He found that composites made from biochar had comparable properties to expensive materials made from carbon tubes and graphene. Biochar is therefore a reasonable substitute for expensive carbon materials, using agricultural waste that is converted into a valuable raw material.

Biochar is not new - it has been used by indigenous cultures to improve soil quality for crop growth for more than 2,000 years. But the potential of biochar goes far beyond this traditional agricultural use and is only now being discovered through in-depth study of its properties. Biochar can be used as a substitute for petroleum-derived carbon materials, for example in composites, opening up a world of applications. According to Mauro Giorcelli, nearly every carbon-black material – like tyres, for example – could be made of biochar. Using more biochar instead of petroleum-based materials would mean less dependence on scarce resources and reducing carbon footprint.

Next to soil applications, Professor Giorcelli sees great potential especially for the use of biochar in cement and concrete in the future – in his opinion this will be “the next large-scale application after the use in agriculture”. Today's cement production releases huge amounts of CO₂ into the atmosphere, contributing to global greenhouse gas emissions linked to climate change. These emissions could be drastically reduced by using biochar in cement production, thereby decarbonizing the manufacturing process.

The production of biochar is a win-win situation: it can be produced in nearly every village, carbon is stored instead of released into the atmosphere, and because biochar is made from biomass “waste”, it solves the problem of waste disposal while creating a useful new resource that can help decarbonize our economy. It is also conceivable that the production of biochar could become a future source of income for cities and municipalities: if carbon storage in the form of biochar production is paid for with carbon certificates, these can be traded on the global carbon market and thus contribute to the budgets of public authorities.

Because biochar can often be reused - for example, a filter used for water purification can have a second life in another application - some researchers like to describe biochar not as a product, but as a system in which material is never lost, but always transformed and reused.

All organic waste has the potential to be converted into biochar. The chemical composition of biochar varies depending on the biomass combusted, resulting in different types of biochar with different characteristics and therefore different possible applications. That’s why material analysis is key. Professor Giorcelli believes that elemental analysis has great potential to characterize biochar by determining its organic and inorganic carbon content, so that the best application can be found for each type of biochar. 

In addition to characterizing biochar, elemental analysis is also important for quantifying the amount of carbon sequestered when it comes to issuing carbon credits.

Whether it's carbon neutrality, carbon sequestration or oil independence, biochar has the potential to play a major role in addressing the big issues facing our society today. We are confident that Professor Giorcelli and his team will contribute to further explore the potential of this long known but newly discovered resource.