Biochar and carbon variations across diverse industrial crops and cultivated wild plant species: implications for flexible biomass supply chains and Biochar Carbon Removals - Preprint

[Geoengineering News]

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=7211142

Authors: David Casini, Lorenzo Bettucci, David Chiaramonti, Efthymia Alexopoulou, Valentin Schlecht, Iris Lewandowski, Moritz Von Cossel

31 July 2026

Abstract 

Biochar production via pyrolysis represents a key option for long-term carbon dioxide removal (CDR) and soil amelioration, as recognized in the EC Delegated Act on Permanent Carbon Removals. Scaling up, however, requires biomass production systems that minimize ecological trade-offs while supplying suitable feedstocks. Here, we characterized biochars produced from nine individually processed feedstock samples representing industrial crops (Miscanthus× giganteus, Cannabis sativa, Crambe abyssinica and Sida hermaphrodita) and cultivated wild plant species (Melilotus officinalis, Tanacetum vulgare, Artemisia vulgaris and Dipsacus fullonum). Under standardized laboratory-scale slow pyrolysis at 550 C, biochar yields (23.8–29.0 wt% db) and H/C molar ratios (0.27–0.32) varied within relatively narrow ranges. In contrast, carbon on a dry basis (66.7–84.0 wt%), fixed carbon (53.1-76.4 wt%), ash (7.1–25.8 wt%) and specific surface area (27–195 m² g⁻ ¹) varied substantially, whereas carbon on a dry ash-free basis ranged from 87.9 to 94.0 wt%. Measured trace-element concentrations were generally low relative to selected EU Fertilising Products Regulation and EBC-Agro limit values; full regulatory or certification compliance was not assessed. Biochar yields and H/C ratios broadly overlapped between the two feedstock categories. These results indicate that a diverse portfolio of individually processed feedstocks can deliver broadly comparable carbon-stability indicators under one standardized conversion process while retaining functional differences among biochars. They support the potential of diversified biomass production systems for flexible biochar supply chains, although defined-mixture and scale-up experiments remain necessary.