Periodic Reporting for period 2 - LigniOx (Lignin oxidation technology for versatile lignin dispersants)
Reporting period: 2018-11-01 to 2020-04-30
The aim of the LigniOx Innovation Action is to demonstrate the techno-economic viability of alkali-O2 oxidation technology (LigniOx) for the conversion of variable lignin-rich side-streams into versatile dispersants, and especially high-performance concrete plasticizers. Both the oxidation technology and the end-product performance will be demonstrated at industrially relevant operation conditions, enabling industrial process installations and entry of novel lignin products into the markets after the project. The valorisation of lignin side-streams will significantly improve the cost-competitiveness and resource efficiency of lignocellulosic biorefineries, and will create low-cost, sustainable raw materials for the chemical industry. The versatile LigniOx technology can be integrated into lignocellulosic biorefineries, or be operated as a stand-alone unit by chemical industry, as demonstrated in the project.
Performance of the produced LigniOx lignins has been tested in mortar and concrete in comparison to commercial reference admixtures. LigniOx lignins show potential to compete with commercial fossil-based concrete admixtures, especially naphta or melamine condensates. Somewhat higher dosage was needed compared to the polycarboxylate ether (PCE) based reference tested in concrete. Oxidised kraft and organosolv lignins had better plasticization performance than oxidised hydrolysis lignin samples. However, also with oxidized hydrolysis lignin the plasticization performance was clearly better than with lignosulphonates, and in best cases, could compete with synthetic naphta condensates. In addition to concrete plasticizers, there are several other end-use possibilities for LIgniOx lignins as versatile dispersants. All the LigniOx lignins have shown good dispersion performance for special carbon black, and at significantly lower dispersant dosage provided an equal performance as the commercial polyacrylic acid and lignosulphonate based reference products. LigniOx lignin has also been tested as a surfactant to enhance the enzymatic hydrolysability in bioethanol production, and also here, comparable yield improvement was shown as with a commercial reference surfactant.
Process simulations have been performed to evaluate the integration effects at kraft pulp mill together with the techno-economic and life cycle assessment (LCA). Based on process simulations, the process concept developed and patented for the LigniOx integration into kraft pulp mill seems techno-economically feasible, and the LigniOx integration can even provide benefits compared to the current lignin isolation processes. Based on LCA of the kraft pulp mill concept, a significant reduction in the global warming potential in comparison with fossil-based plasticizer was shown. At bioethanol production plant, recirculation of solid residue from oxidation stage back to the ethanol process improved the yield. However, reduced filtration rate and increased sodium load to the bioethanol process were the drawbacks. LCA for the LigniOx integration into bioethanol plant is on-going.