In collaboration with the above mentioned cooperation partners and under coordination of the Fraunhofer Institute for Chemical Technology ICT, within the project LignOx a technology platform is developed, which enables the step wise conversion of a classic pulp mill into a pulp mill bio refinery. The starting point is the lignin‑rich black liquor, which is produced as a side product in the so called “Kraft process“ during pulp manufacture, and isolated lignins. By oxidative depolymerization of lignin under batch and continuous flow conditions in laboratory scale, bi- and polyfunctional lignin derivatives will be generated and characterized. In addition, separation techniques of the formed reaction products will be investigated. Within the second part of the project, through targeted derivatization of the previously produced oligomeric lignin building blocks, new utilization pathways for technical lignin will be presented, which differ from the present thermal and material use (e.g. concrete additives). Among other things, synthetic modified lignin building blocks could have great potential in low‑emission products such as resins, adhesives or polyurethane (PU) systems. Hence, exemplary, the implementation and utilization of the functionalized Kraft‑lignin building blocks within PU‑systems as well as compounding agents in thermoplastics is investigated.
With the described investigations, the project will form a connection between the material use of Kraft‑lignin and its theoretical potential in biomaterials. Simultaneously, by increasing the ratio of the material use of lignin fossil resources such as crude oil and natural gas can be saved and an impact on the greenhouse effect through development of CO2 neutral technologies can be reduced. In addition, the efficiency, competitiveness and sustainability of present and future pulp mills could be enhanced by the development of new fields of application for oxo‑functionalized lignin oligomers.