Biochar

In 2014, the prevailing scientific literature suggested applying 10–20 tonnes of biochar per hectare to see agronomic effects. We showed that 750 kg/ha of nutrient-enhanced biochar, concentrated in the root zone, consistently increased yields in the tropics — and that the combination with organic nutrients even outperforms biochar with mineral fertiliser loading.

Biochar cannot be regulated, certified, or traded without reliable analytics. The institute has been involved in defining how biochar is measured since organizing the first international inter-laboratory comparison for biochar in 2013 — and continues to develop the proxies and methods that underpin the certification standards.

Biochar alone captures 30–50% of the carbon in the original biomass. PyCCS — Pyrogenic Carbon Capture and Storage — showed that by sequestering all three pyrolysis products, the efficiency can exceed 70%, making biomass pyrolysis a serious negative emission technology. The concept, coined by the Ithaka Institute, now has a Wikipedia entry and was cited by the IPCC.

From the biochar vineyard trial in the Swiss Alps (2007) to a nine-system carbon farming experiment in subtropical Nepal, the institute's field trial programme spans nearly two decades, three continents, and crops ranging from pumpkin, chili, and banana to cocoa, coffee, and tobacco.

Biochar and enhanced rock weathering are the two most scalable land-based CDR methods. PyMiCCS combines them into one intervention - co-pyrolysing biomass with silicate rock powder or co-applying both to soil - unlocking synergies in carbon removal, soil restoration, and nutrient supply that neither achieves alone.

When we established Europe's first biochar field trial in 2007, we mixed charcoal with compost by intuition — there was no scientific protocol, just the logic of feeding soil the way farmers always did for the last 10'000 years. That intuition turned out to be right, and proving why it works became one of the institute's most consequential lines of research.

Conventional activated carbon is produced from fossil coal. The Empyrion project demonstrated that locally available biomass residues can be pyrolysed and activated into high-performance sorbents for wastewater treatment — replacing fossil precursors with a climate-positive alternative. Recent work extends this to one of the most pressing contamination challenges: PFAS.

Compost and digestate returned to agricultural soil are generally contaminated with more or less plastic. Over time, this builds up as microplastic contamination with no natural degradation pathway. Pyrolysis can break this cycle: under controlled conditions, the plastic in the feedstock is fully eliminated while most of the carbon and nutrients are preserved in the biochar and pyrolysis oil. We proved the concept and demonstrated that under controlled conditions no new contaminants are created.

Biochar is not a finished product out of the reactor. By blending metals, minerals, or acids into the feedstock or the pyrolysis process, its properties can be engineered for specific functions — from oxyanion adsorption to nitrate retention and magnetization to increased carbon efficiency. The institute's work on biochar modification laid early groundwork for what is now one of the fastest-moving areas in biochar science.