High-Temperature Corrosion in Biomass-Fired Systems: Mechanisms, Mitigation, Strategies, and Challenges for the Brazilian Bioenergy Sector

Biomass combustion is critical to Brazil’s energy transition, but high-temperature corrosion remains a major operational barrier in industrial boilers. Following a systematic search of Scopus (2000–2026; 977 records screened, 159 included), this review synthesizes the physicochemical mechanisms driving ash deposition and high-temperature corrosion in biomass-fired systems, identifying chlorine-induced active oxidation and alkali-driven hot corrosion as the dominant degradation pathways, and detailing the synergistic, self-reinforcing interaction between the two. Mitigation strategies:fuel management, additive dosing, protective coatings, and advanced alloys are critically compared on effectiveness, cost, and industrial readiness, showing that no single strategy is simultaneously effective, inexpensive, and mature. Unlike previous reviews, this work integrates a quantitative assessment of the Brazilian industrial landscape, distinguishing a well-documented core (sugar cane bagasse, black liquor) from an undocumented but rapidly growing frontier (rice husk, corn cob), and closes with three priority research gaps: open ash/exposure databases, standardized antislagging and cladding-thickness metrics, and field-validated corrosion prediction, with concrete actions proposed to address each.