Catalytic Hydrogenolysis of Lignin for the Synthesis of Biokerosene

Abstract

In this work, catalyst consisting of Ru deposited on hypercrosslinked polystyrene (HPS) was investigated in the process of hydrogenolysis of lignin isolated from different substrates. For sawdust, the maximum yield of the desired products was achieved with the use of acetic acid lignin, sunflower husk, and buckwheat husk when using the Klasson lignin. Analysis of hydrogenolysis products showed that the main substances formed in the process are benzene, phenol and their derivatives. In the process of hydrogenolysis of lignins at a pressure of 1 MPa hydrocarbons containing up to 9 hydrocarbon atoms were mainly obtained (78 %). Such hydrocarbons can be used as motor fuels. To increase the yield of hydrocarbons C9+, experiments were conducted to vary the temperature and pressure. The optimal reaction conditions allowing obtaining the highest yield of the target products (C9+ hydrocarbons) were found to be the following: the processing time 1 h, the temperature of 300 °C, the partial pressure of hydrogen of 4 MPa, the stirring speed of 1500 rpm. The 3 % Ru/HPS catalyst showed high stability during hydrogenolysis (up to 5 consecutive cycles without regeneration).