Thermodynamic approach to simulate the HydroDeOxygenation process of Lignin

The high availability of lignin as a renewable carbon source, coupled with its chemical structure rich in aromatic compounds, offers a potential opportunity to convert lignin into chemicals, fuels and other valuable building blocks. Within this context, the hydrogenation process was considered a good pathway to obtain profitable compounds converting lignin. In the present work, a novel thermodynamic approach was carried out by lignin hydrogenation simulation. First, a lignin property model was developed in the process simulation software Aspen Plus® and based on its chemical structure and thermodynamic properties. Subsequently, a set of reactions was considered for the hydrogenation process, and the “temperature approach" was used to fit the reactor's yield experimental data available in the literature with the reaction network model predictions. This procedure enabled the replication of the results obtained in the reactor without the need to directly consider the reaction kinetics. The results showed that there is a good approximation between experimental and modelling results for each of the four different catalysts tested in the literature works data. The main potential utilization of the model consists in the forecasting of the lignin HDO process individuating the hydrogen needs and the best pressure to use to maximize the yields to aromatics also testing several kinds of lignin sources.