Skip to main content

Smart Technologies for the Conversion of Industrial Lignins into Sustainable Materials

Periodic Reporting for period 2 - SmartLi (Smart Technologies for the Conversion of Industrial Lignins into Sustainable Materials)

Reporting period: 2017-01-01 to 2018-06-30

Today nearly all aromatic chemicals and building blocks originate from fossil sources, whereas lignin as a phenolic natural polymer could provide a valuable renewable aromatic resource for the chemical industry. the project aíms at adding value to the underexploited biomass side stream lignin, providing quality ensured homogeneous raw materials for manufactures and industrial end- users, lowering the need for oil based raw materials in the production of materials and chemicals and enhancing sustainable processing e.g. by reducing the GHG emissions. In SmartLi new technologies are developed for using technical lignins as raw materials for biomaterials and their industrial feasibility is demonstrated. The technical lignins included in the study are kraft lignins, lignosulphonates and bleaching effluents, representing all types of abundant lignin sources. The raw materials are obtained from industrial partners. The technical lignins are not directly applicable for the production of biomaterials with acceptable product specifications. Therefore, pretreatments has been developed to reduce their sulphur content and odour and provide constant quality. Thermal pretreatments are shown to to improve the material properties of lignin to be used as reinforcing filler in composites, while fractionating pretreatments provided streams to be used as plasticizers. The development of composite applications is led by an industrial partner. Base catalysed degradation was used as a means to yield reactive oligomeric lignin fractions for resin applications. The degradation was followed by downstream processing and further chemical modification for polyol replacement in PU resins. Also PF type resins for gluing and laminate impregnation, and epoxy resins were the target products. Full LCA, including a dynamic process, will support the study.
Several protocols based on solvent fractionation and membrane separation have been developed and tested. With these, it has been possible to produce polymeric lignin and lignosulphonate fractions with improved characteristics in respect to sulphur content. By heat treatment, the sulphur content could be reduced to some extent, and also lignin-derived odour compounds were partly removed. It has been confirmed that fractionation can be used as a means to recover a lignin fractions with equal properties from different starting lignin materials. This is the prerequisite for providing lignin with constant quality to be used as raw material. All starting lignins and fractions have been thoroughly characterized. In addition, lignin modificates produced in the project have been characterized. Selected pretreatments have been up-scaled and requested amounts have been delivered for application testing. Two pilot-scale fractionations were performed, by using aqueous ethanol and acetone.

New technologies for depolymerisation of lignin and separation of depolymerisation products have been developed. Base catalyzed depolymerization of both Kraft lignin and lignosulphonates has been systematically studied. Cross-flow membrane filtration has been studied as a means to fractionate BCD fragments in a non-thermal, hence gentle and energy-efficient manner. It was shown that higher and lower molecular weight BCD derivatives can be separated directly from the alkaline reactor water and thereby debottlenecking the current downstream separation process. . The BCD process was successfully scaled-up using a two-stage membrane process at semi-pilot scale and two selected pH-stable NF modules.

The usability of lignins and their fractions has been assessed in four areas of industrial applications: 1) Thermoplastic compounds; 2) Phenolic resins; 3) Polyurethane foams and 4) Epoxy composites and coatings. The experimental activities allowed to demonstrate the antioxidative properties of lignin and lignin fractions i and their processability on a pre-industrial scale in several thermoplastic polymers. The results show that lignin can replace high-cost antioxidants in composites and provided even better performance compared to commercial ones against heat and light. The lignin use as reinforcing blend partner of composites was studied under industrial conditions to confirm the improved mechanical properties of lignin fractions obtained by solvent fractionation. . Modified kraft lignin was successfully used in both rigid and flexible PU foams.Use of kraft lignin and its fraction in long pot-life and 2K epoxy formulations for applications in composites, adhesives and coatings was carried out successfully.

An integral part of the work was the assessment of technologies and products, developed in terms of ecological, economic and social aspects. The early implementation of sustainability assessment and respective indicators is a prerequisite to foster the effectiveness of innovation processes towards an efficient resource use right from the beginning. In order to systematically consider the environmental aspects a Life Cycle Assessment (LCA) and techno-economic analyses were carried out for the newly developed lignin based products as well as the new technologies. It was concluded that a streamlined LCA in line with R&D advancements can support the entire project by providing important information on potential environmental impacts and provide different scenarios in order to expand the idea of future development.The issue of an early assessment of potential market barriers and incentives of currently developed products is often requested, but seldom done. This might be attributed to the difficulties occurring due to a lack of available information and/or experts as well as specific methods.The implementation of economic and ecological assessment already during an early research stage may be the key to successfully develop sustainable processes and produc
This project aimed to bring new bio-based products to markets. The technologies developed can be integrated in the current industrial landscape when producing biomass based products and intermediates and building blocks to the existing industries and value chains. The project will identify and target market niches for lignin-based products and provides a strategy for market penetration. SmartLi developed applications for technical lignins which are presently not valorised due to their limited availability or performance as such. The technologies developed enabled improvement of the raw material quality, especially constant quality, which leads to their easier use in valorisation processes and significantly facilitates the up-take into markets, As a result, several industries are impacted. The chemicals and materials have applications in a wide range of material uses in the industries and finally at the consumers. The impact combines sustainability of the renewable materials and the competitive edge of the end use sectors in question. Based on the results, new market opportunities can be created, which secure employment particularly in the product development and engineering. 'The project facilitated also the renewal and competitiveness of pulp and paper industry through production of renewable raw material, i.e. lignin, for the needs of chemical industry and material producers.