Pelletization can unlock the unrealized potential of lignocellulose as a resilient feedstock for biomanufacturing: enzymatic saccharification of biomass pellets

Lignocellulose, as a plentiful and renewable carbonaceous resource, presents an alluring alternative to fossil fuels for sustaining industries in the pursuit of a resilient bio-based economy. Sugars derived from lignocellulosic biomass play a central role as versatile platform intermediates for feeding microorganisms or as starting chemicals for manufacturing value-added fuels, chemicals, and materials. However, commercialization faces challenges due to the complexity and high costs associated with feedstock logistics and conversion processes. Pelleting offers a potential solution by addressing logistical issues while providing additional benefits for downstream conversion that may outweigh the extra costs associated with pelleting. To fully unlock the economic and sustainable potential of lignocellulosic biomass in biorefineries, recent advances in pelleting technologies and their impacts on downstream pretreatments and enzyme-mediated conversion are critically reviewed. Pelleting has been shown to improve enzymatic digestibility yields by 5‒20%. The process variables, product attributes, and their influences on bioconversion are discussed. More significantly, a thorough discussion of the effect of pelleting on various pretreatments, concerning diverse feedstocks, as well as their interplay, is provided to inform the design of future pelleting and pretreatment processes. Finally, practical considerations, including energy consumption, costs, and environmental impacts, are discussed, alongside an exploration of cutting-edge technologies and strategies in this field.