High-value utilization of biomass pellets: paradigm shift from alternative fuel to multifunctional chemical platform—A review

Biomass emerged as a unique renewable energy capable of achieving net-zero or even negative carbon emissions. However, some significant challenges, such as low energy density and poor grindability, still block the way towards industrial application. Pelletizing into pellets is a core strategy to address the bottlenecks limiting its efficient utilization. In this work, a review of the latest progress in biomass pelletizing technologies were performed. Furthermore, the cutting-edge pathways were discussed for the high-value utilization of pelletized biomass. In the energy sector, the pelletized biomass significantly enhances combustion efficiency of the industrial boilers and facilitate the co-firing of biomass in coal-fired power plants. In the chemical industry, as an ideal precursor, pelletized biomass can be directionally converted into high-value chemicals via catalytic pyrolysis and hydrothermal liquefaction, highlighting the techno-economic potential of integrated fuel-chemical production. However, industrialization is still hampered by high feedstock collection costs, underdeveloped continuous production equipment, and the absence of a full life-cycle carbon accounting system. Developing modular production systems, AI-driven intelligent coupling of the pelletizing-conversion processes, and functionalization it based on negative-carbon biochar, is important to transform biomass from an alternative energy into a core carrier for carbon neutrality, accelerating the pace of clean energy substitution.