Conversion of lignin to aromatic-based chemicals (L-chems) and biofuels (L-fuels)

Conversion of lignin into chemicals and biofuels was performed using the commercial Kraft lignin, Indulin AT. Lignin was depolymerised in an aqueous alkaline solution using a continuous flow reactor generating four fractions. First is the gas fraction (mainly CO2), the second includes methanol, acetic acid and formic acid, thus defined as small organic compounds and third one (up to 19.1 wt.% of lignin) is mostly composed of aromatic monomers. The fourth fraction (45–70 wt.%) contains oligomers (polyaromatic molecules) and modified lignin. Pyrocatechol was the most abundant product at high severities (315 °C) with selectivity up to 25.8%. 31P NMR showed the loss of almost all aliphatic OH groups and apparition of catechol groups during depolymerisation.