Biomass gasification as a cornerstone of the circular bioeconomy: a review of technology, barriers, and deployment strategies

The global shift toward a circular bioeconomy and net-zero emissions has positioned biomass gasification as a pivotal technology for sustainable energy and waste management. This review comprehensively synthesizes recent advancements, critical barriers, and strategic pathways for large-scale deployment. The fundamental process and feedstock systems are first examined, including key innovations in pre-treatment (e.g. torrefaction, hydrothermal carbonization) and syngas conditioning (e.g. plasma-cracking, biochar catalysts). The analysis then delves into persistent operational challenges, such as tar-induced equipment fouling and ash-related issues (slagging, agglomeration), highlighting the trade-offs between mitigation strategies and byproduct valorization. The techno-economic assessment, based on a critical review of data from the existing literature, reveals that while centralized models benefit from economies of scale, the financial viability of all scales is highly sensitive to feedstock costs and supportive policies like carbon pricing. Crucially, the review identifies three critical research gaps: the scarcity of long-term operational data, the need for dynamic techno-economic and life cycle assessments, and the development of feedstock-adaptive designs. We propose strategic recommendations centered on digitalization through artificial intelligence-driven control and digital twins, differentiated policy levers to support projects ranging from small-scale (<1 MWe) to large-scale (>10 MWe) applications, and the integration of gasification into circular systems, such as integrated waste-to-energy facilities in urban areas or the co-location of gasification plants with agricultural processing industries to create industrial symbiosis to maximize resource efficiency. This work provides an integrated framework for stakeholders, guiding future research and policy to accelerate the transition of biomass gasification into a reliable, flexible, and sustainable energy solution.