** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** THE CONVERSION OF A LOW-COST BIOREFINERY BYPRODUCT, LIGNIN, TO HIGH-VALUE CHEMICALS (E.G., AROMATIC ACIDS AND AVIATION FUELS) PROVIDES A VIABLE WAY TOWARD PROFITABLE BIOREFINERY, WHICH CAN MITIGATE RISING OIL PRICES OR CHEMICAL SUPPLY CHAIN VOLATILITY. HOWEVER, SUCH A PROCESS HAS BEEN GREATLY HINDERED BY MANY CHALLENGES INCLUDING LOW SELECTIVITY, LOW YIELD, HARSH REACTION CONDITIONS, AND LIGNIN HETEROGENEITY.HEREIN, WE HYPOTHESIZE THAT A ONE-POT AND TWO-STEP BENZYLIC OXIDATION PROCESS CAN SELECTIVELY MODIFY THE LIGNIN SIDE CHAIN, LEADING TO HIGH YIELDS OF AROMATIC ACIDS (AA) FOR BIOPLASTICS AND REMAINING LOW MOLECULAR WEIGHT AROMATICS (LMWA) TO BE UPGRADED TO SUSTAINABLE AVIATION FUEL (SAF). THIS HYPOTHESIS IS SUPPORTED BY THE PRELIMINARY DATA OF UNIQUE OXIDATIVE LIGNIN DEPOLYMERIZATION UNDER MILD CONDITIONS. THE SELECTIVITY OR YIELDS TOWARDS AA OR SAF WILL BE FURTHER IMPROVED BY DESIGNING THE CATALYSTS USING A UNIQUE DATA-DRIVEN APPROACH THAT COUPLES INVERSE MOLECULAR DESIGN THEORY. THE EFFICIENT OPERATION WILL BE ACHIEVED BY ONLINE OPTIMIZATION BASED ON REINFORCEMENT LEARNING ALGORITHMS TO ENABLE A MORE EFFICIENT OPERATION THAT IS ADAPTIVE TO VARIABLE FEEDSTOCK HETEROGENEITY AND OPERATION CONDITIONS. THE TEA/LCA ANALYSIS WILL BE APPLIED TO EVALUATE THE TECHNICAL AND ECONOMIC FEASIBILITY AND ENVIRONMENTAL POTENTIALS OF THE ENTIRE PROCESS.THE PROJECT RESOLVES THE KEY PROBLEMS IN LIGNIN VALORIZATION INCLUDING SELECTIVITY, YIELD, REACTION, AND OPERATION STABILITY FOR PROFITABLE LIGNOCELLULOSE-BASED BIOREFINERY SYSTEMS. IT HAS THE POTENTIAL TO COMPENSATE FOR THE AROMATIC SHORTAGE FROM PETROLEUM RESOURCES AND CONTRIBUTE TO THE BIDEN ADMINISTRATION'S ACTION TO PRODUCE 3 BILLION GALLONS OF SAF/YEAR BY 2030 AND REDUCE AVIATION CARBON EMISSIONS.