Recent Lignin Announcements Show Repeated Mistakes, Not Progress

February 2017 had two noteworthy announcements pertaining to lignin-based materials: VTT Technical Research Centre of Finland announced the development of a reactive lignin product to replace phenol in phenol formaldehyde adhesives and the Institute of Textile Chemistry and Chemical Fibers (ITCF) Denkendorf announced its participation in the “LIBRE Project” (Lignin Based Carbon Fibers for Composites). However, lignin’s successful use in materials has faced challenges including processing, derivatization, lignin’s unpleasant odor and dark colors, and questionable cost and performance benefits ([see the report “Assessing Lignin-based Material Innovations“] client registration required). As such, we have given Lux Takes based on the probability of these announcements for overcoming these issues:

  • VTT develops reactive lignin product as a phenol replacement (Lux Take: Caution): VTT recently announced its CatLignin technology to produce reactive lignin, which it described as an ideal replacement phenol in phenol formaldehyde adhesives. Drivers for CatLignin’s use include the toxicity of phenol, legislation against volatile organic compounds (VOCs), and a reduced CO2 footprint. VTT is now searching for partners to both scale its technology and develop applications for its material. Lignin-based adhesives have struggled historically, showing no performance or cost advantages over incumbents. Although VTT’s lignin, unlike previous attempts at lignin-based adhesives, is reactive, it does little else to overcome the other challenges faced by lignin-based adhesives, including product variability, dark color, odor, and long curing times. Moreover, while VTT highlights its material’s potential uses, the onus is on partners for applications development. This strategy contrasts with West Fraser’s strategy to use its lignin-based adhesive internally before commercialization. Although West Fraser’s adhesive has an unclear value proposition, its internal use strategy allows it to improve the performance and cost of its technology for future external customers, an advantage that VTT lacks. While VTT’s CatLignin provides a novel reactive form of lignin for adhesives, it is not clear whether or not it provides performance or cost advantages over incumbent adhesives. Moreover, VTT’s reliance on external parties for scale and development will only make success more difficult
  • ITCF Denkendorf announces participation in the LIBRE Project (Lux Take: Strong Caution): The LIBRE Project, part of the European Commission Horizon 2020, aims to convert lignin into precursor fiber (replacing the traditional conversion of acrylonitrile into polyacrylonitile [PAN] fiber), replace the traditional thermal treatment steps with more energy efficient treatments utilizing microwaves and high-frequency radiation, and add new plasma surface treatments that replace traditional liquid chemical surface treatment and sizing. In particular, ITCF will be focusing on converting raw lignin to precursor fiber using chemical functionalization for stability and melt spinning. Then, ITCF and partners will work on conversion of these precursor fibers to carbon fibers.Although the LIBRE Project aims to produce an improved lignin-based carbon fiber, there does not appear to be anything novel about its approach. For instance, the U.S. Oak Ridge National Laboratory (ORNL) has been developing alternative thermal treatments, including atmospheric plasma oxidation and microwave-assisted plasma carbonization, for several years to reduce cost and residence time. What’s more, even ORNL is not using lignin-based carbon fiber to reinforce its bio-based polymers because of the material’s inferior performance. Thus, the LIBRE Project will likely fail, given its lack of distinction from previous failed efforts.

In spite of lignin’s potential for use in materials, there has been limited progress in actual materials development due to inferior cost and performance. The most promising examples, though, are those that take novel approaches to product development, such as West Fraser’s internal lignin-adhesive testing, and the ORNL decision to only develop a partially lignin-based material – its ABL (acrylonitrile, butadiene, lignin) thermoplastic, which shows improved toughness over ABS (acrylonitrile butadiene styrene). However, neither VTT nor ITCF has targeted a novel strategy, instead taking traditional approaches that have already failed. Readers interested in lignin should, instead, focus on developers taking drastically different strategies for lignin-based material commercialization.

By: Gihan Hewage