Green upcycling of jet fuel precursors via hydrothermal liquefaction of plasma-pretreated cellulosic materials over an Fe–alkaline catalyst

This study developed a green and integrated hydrothermal liquefaction process for efficiently converting cellulosic materials into ketone-based aviation fuel precursors. To address issues such as low hydrolysis efficiency and weak catalytic activity during biomass hydrothermal conversion, dielectric barrier discharge non-thermal plasma pretreatment was employed, combined with an Fe/NaHCO 3 synergistic catalytic system to regulate the reaction microenvironment and enhance product selectivity. First, plasma pretreatment utilizes high-energy electrons and active particles to disrupt the crystalline regions and hydrogen bonding network of cellulose, significantly reducing its crystallinity and exposing more reactive hydroxyl sites, thereby improving the hydrolysis and conversion efficiency of cellulose under hydrothermal conditions. Experimental results showed that after DNTP pretreatment at 12 kV for 15 min, the relative peak area of ketone products from cellulose increased by 28.2% compared to the untreated sample under hydrothermal conditions of 260 °C for 30 min. Furthermore, the introduction of NaHCO 3 together with Fe formed a synergistic catalytic system. The alkalinity of NaHCO 3 effectively neutralizes organic acids generated during liquefaction, eliminating H + poisoning of Fe active sites, while promoting the conversion of Fe into highly active Fe 3 O 4 and enhancing the Fe 3+ /Fe 2+ redox cycle. This suppresses intermediate condensation and coking, thereby improving the selectivity and carbon efficiency of ketone synthesis. Using holocellulose derived from rapeseed straw as feedstock, a ketone selectivity of 60.7% was achieved at an Fe-NaHCO 3 mixing ratio of 1:1. This process is characterized by its green nature, high efficiency, and ease of catalyst recovery, offering a promising technological pathway for the production of sustainable aviation fuels from biomass.