Mild photothermal-catalyzed conversion of kraft lignin into hydrocarbon-rich liquid fuel using platinum-loaded titanium oxide nanorods

A continuous two-stage photothermal catalytic system utilizing titanium oxide nanorods loaded with platinum (Pt/TNR) was developed to facilitate the efficient depolymerization of kraft lignin in an ethanol solution for the production of hydrocarbon fuels. The study demonstrated that the liquid yield increased by 38.6 % with the modified catalyst Pt/TNR compared to the absence of a catalyst. Under moderate conditions (220°C, 8 h), 94.0 % of kraft lignin was converted into liquid yield, achieving a low calorific value of 22.12 MJ/kg—an increase of 5.77 MJ/kg compared to concentrated kraft lignin. Under the conditions of no catalyst, TNR, and Pt/TNR, the corresponding lignin degradation products change from oxygen-containing compounds (carboxylic acids and alcohols), monophenolic compounds, to long-chain hydrocarbons, highlighting the powerful hydrogenation deoxygenation effect of Pt/TNR and its ability to produce liquid fuels with significantly higher hydrocarbon content. This study offers an energy-efficient approach for generating hydrocarbon fuels from kraft lignin.