Research activities

Processing and fractionation of kraft black liquor for value-added products

One part of the biorefinery-concept is to identify and establish new processing routes utilizing industrial or agricultural waste-streams for the production of biobased products while digressing from energetically conversion. Kraft black liquor, a by-product of the chemical pulp production from wood is one typical example of an industrial process stream which is currently thermally converted mainly for the recovery of process chemicals as well as energy. In doing so, the potential resources like the biopolymer lignin, carboxylic acids from hemicelluloses and other phenolic compounds e.g. vanillin are utilized as energy and not for the synthesis of value-added products.
Vanillin as an example for fractionized aldehydes is currently used as a precursor for the electrolyte production for aqueous redox flow batteries [1].
During my PhD-studies I am processing kraft black liquor utilizing different unit operations for the extraction of mentioned compounds, particularly low-molecular weight fractions like aldehydes and quinones to increase the cascade utilization of wood.

[1]   W. Schlemmer et al., “2-Methoxyhydroquinone from Vanillin for Aqueous Redox-Flow Batteries,” Angewandte Chemie (International ed. in English), vol. 59, no. 51, pp. 22943–22946, 2020, doi: 10.1002/anie.202008253.