Safety aspects of torrefied biomass: Prosperous and dangerous process for green transition

In this paper we present an analysis on safety aspects of torrefied biomass. Torrefaction is increasingly deployed to upgrade biomass for co-firing and as a precursor to advanced biofuels, yet the same pretreatment can increase dust generation and modify self-heating behaviour, elevating fire and explosion risks. This paper synthesises the comparable 20-L sphere explosibility datasets for raw and torrefied wheat straw, rape straw and vine shoots, a harmonised interpretation of reported K st , P max and (dp/dt) max under standardised test conditions, and a keyword co-occurrence network (1984–2025) interpreted through Perrow’s Normal Accident Theory to connect material hazards with system-level drivers. Across the three residues, torrefaction increased (dp/dt) max by ∼20–25% while remaining in the St1 class, implying ∼17–26% larger vent areas when translated to a representative reduced explosion pressure target. The bibliometric layer indicates a persistent separation between renewable-energy narratives and discourses on explosion prevention or explosion protection and functional safety, with only limited bridging emerging in recent years. We therefore position torrefaction mid-way on a complexity–coupling continuum between conventional biomass handling and the more tightly coupled high temperature pyrolysis and high pressure hydroprocessing used in sustainable aviation fuel (SAF) production. We argue that treating accidents as “normal” in such coupled systems could motivate design- and governance-level measures (decoupling, monitoring, barrier management) that complement standard prevention and certification practices. • Torrefaction improves fuel properties yet increases dust explosibility and storage hazards. • Standardized 20-L sphere data show higher (dp/dt) max and often higher K st /P max for torrefied dusts. • Increased explosion severity translates into larger venting demand and stricter prevention/protection requirements. • Self-heating and off-gassing expand the hazard perimeter from acute events to chronic storage-related risks. • Normal Accident Theory and keyword-network mapping reveal how coupling/complexity and production pressure degrade learning and barriers, especially across supply and refuelling interfaces relevant to SAF hubs.