Periodic Reporting for period 3 - LigniOx (Lignin oxidation technology for versatile lignin dispersants) Reporting period: 2020-05-01 to 2022-02-28 Summary of the context and overall objectives of the project Lignin is the most important by-product from lignocellulosic biorefineries, and a valuable renewable resource for bio-based industries. Annually over 70 million tons of lignin is extracted from wood as a by-product of the pulping industry. Substantial amount of lignin is also expected to originate from the 2nd generation bioethanol production. These lignocellulosic biorefineries are currently actively looking for opportunities to valorise the lignin by-products in high-value products instead of using in (low-value) energy production. Furthermore, lignin offers a renewable low-cost raw material for chemical industry, improving resource sufficiency and promoting replacement of fossil-based chemicals and materials. However, to fully exploit these raw material streams, there is an urgent need to commercialise economically and sustainably viable lignin upgrading process technologies that are adaptable to lignin side-streams originating from different processes and raw materials. The aim of the LigniOx Innovation Action was 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 were demonstrated at industrially relevant operation conditions, aiming to enable industrial process installations and entry of novel lignin products into the markets after the project. The valorisation of lignin side-streams using the LigniOx technology can improve the cost-competitiveness and resource efficiency of lignocellulosic biorefineries, and can 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. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far In the LigniOx project, industrially applicable oxidation and post-treatment concepts were developed for lignin by-products originating from variable industrial processes (kraft, organosolv, 2G bioethanol production) and feedstock (softwood, hardwood, wheat straw). In all cases, the oxidation conditions, post-treatment protocol and process concepts were optimized in order to obtain high-performing lignin derived concrete plasticizer, as well as techno-economically feasible and safe oxidation process. Based on the oxidation protocols developed, a pilot scale oxidation reactor was constructed, and the LigniOx oxidation and post-treatment were successfully scaled-up for all the lignins. The viability of the process concept was demonstrated in industrially relevant conditions with kraft lignin and industrial product prototypes were produced. Performance of the produced LigniOx lignins was 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. A blend of kraft or organosolv lignins with a commercial product met the requirements of a superplasticizer. Several other end-use possibilities for LigniOx lignins as versatile dispersants were investigated. All the LigniOx lignins showed 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 was 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. Furthermore, LigniOx lignins were tested for applications as gypsum plasticizer, anti-scaling agent, and flotation aid (depressant) with promising results. Conceptual design was performed to aid the integration of industrial LigniOx processes at the biorefineries after the LigniOx IA. Techno-economic evaluation as well as environmental life cycle assessment (LCA) and socio-economic impacts were assessed for the studied value chains in comparison with a benchmark superplasticizer product. The LCA study clearly demonstrated that integrating the LigniOx production to an existing pulp mill or a biorefinery gives significant environmental benefits compared to a fossil-based reference product or a stand-alone production facility, but even the stand-alone cases exhibited good overall performance. For kraft lignin, a techno-economically feasible process concept that can be integrated into the kraft pulp mill could even provide benefits compared to the current lignin isolation processes and was patented. Regulatory issues were considered to ensure that the safety, quality, and purity of the new products are in line with EU legislation. LigniOx products do not need REACH registration in EU nor are they considered as microplastics due to their high solubility. Biodegrability of the studied LigniOx products was better than that for the starting materials. For application testing, safety data sheets (SDS) and CAS numbers were applied and approved for LigniOx materials. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) The work carried out in the LigniOx project leads the way towards a commercially viable process that can be integrated into a biorefinery. Techno-economically promising process concepts have been developed for lignins originating from variable processes (kraft, organosolv, bioethanol production) and feedstocks (softwood, hardwood, wheat straw), and oxidation was successfully scaled-up for all lignin types using the pilot reactor constructed in the project. For kraft lignin, the process was demonstrated in industrially relevant conditions. The LigniOx lignins produced showed plasticizing performance that can compete with some commercial fossil-based concrete admixtures, such as naphthalenesulfonate, but could also be an alternative to polyacrylic acid-based commercial dispersants of special carbon black. Additional application possibilities of LigniOx lignin as plasticizer for gypsum, an antiscaling agent or a flotation aid (depressant) showed promising results and all can contribute to the establishment of a more sustainable and low carbon industry. Substantial reduction of global warming potential compared to the current synthetic products was also shown in LCA assessment of LigniOx lignins. As a result of LigniOx project, lignin upgrading technology for production of versatile lignin-based dispersants is ready for industrial installation of a demonstration size plant right after the project, and the new LigniOx products could at the earliest, enter the markets within 4-5 years, creating new business opportunities for lignocellulosic biorefineries and chemical industry. The next steps envisioned after the project include the production of the LigniOx products in large scale for industrial scale end-use testing. This would enable the increase of the technology readiness (TRL) level of the products and further promote commercialisation of the LigniOx technology. LigniOx logo
