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Valorization of lignocellulosic biomass via anaerobic digestion (AD) is limited by its reluctant structure, leading to a substantial energy remaining in the solid digestate. To mitigate this effect, the integration of AD and pyrolysis has attracted attention in recent years. However, the energy recovery efficiency of this cascading system is still unclear, especially the time node. Herein, a comprehensive evaluation of this integration, using varied AD periods, was conducted, to produce biogas, bio-oil and biochar, and to enhance the energy recovery, from the perspective of energy flow. The result indicated that the accumulative CH 4 yields increased from 33.23 to 249.20 mL/g VS as the AD time increased from 3 to 15 days. Pyrolysis of the obtained solid digestate obtained biochar from 28.81 to 35.96 %, while the bio-oil and pyrolysis gas slowly decreased. The highest energy efficiency of 71.9 % with a net energy gain of 2.0 MJ/kg wet biomass was achieved by the coupled system optimization at an AD time of 12 days as suggested by the energy flow analysis. This study provides new insight for the maximal conversion of biomass waste into energy products and provides a new way of recycling it., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)