Porous activated carbon-based solid acid catalysts (AC‑SACs) have gained significant attention as promising materials for biomass conversion due to their high surface area, tunable porosity, and strong acidic functional groups. Biomass conversion is essential for the sustainable production of biofuels, including biodiesel, and other value‑added chemicals, offering an alternative to fossil-based resources. This review summarizes recent advances in the synthesis, characterization, and catalytic pe