Biomethane conversion of waste lignin: expanding use of lignocellulosic residues

This project aims to develop biomethane conversion of waste lignin from Kraft black liquor and from anaerobic digestion of agricultural and forestry residues. Anaerobic digestion will be conducted of agricultural residues and reject wood chips that have been “pretreated” using high pressure steam. Waste lignin recovered from black liquor using known methods and from digestate as described and claimed in WO2020/033633 will be oxidized to water soluble products. Anaerobic digestion of these products will be developed using a fixed orientation, fixed biofilm reactor. This technology should make the business case for biomethane con-version of agricultural residues highly favorable. Biomethane conversion of surplus Kraft lig-nin alone can account for 9-13% of Swedish transport needs. The potential contribution of this technology to fossil free transport by 2030 will be assessed where hypothetical policy instruments are applied to increase the percentage of methane fueled vehicles.