Lignin R&D and Innovations

VTT develops CatLignin, a reactive lignin for wood adhesives

VTT Technical Research Centre of Finland has developed technology known as "CatLignin" to produce reactive lignin from pulp industry side streams to be used as a replacement for toxic phenol compounds in wood adhesives that are widely used in wood products and furniture.

Traditionally phenol and formaldehyde containing adhesives are used in wood products such as plywood, laminated veneer lumber, particle wood panels and laminates. There is a strong legal drive from sanitary authorities in Canada the US and the EU towards more stringent limitations up to a complete ban of phenol formaldehyde (PF) adhesives in wood panels. The reasons is that they are actually releasing formol for years after manufacturing. Another important driver is the Act on Public Procurement enacted at the beginning of the year 2017 which highlights these public health and environmental considerations. This, in turn, drives wood product manufacturers to find bio-based and safe alternatives to these petroleum-based, toxic and expensive adhesive components.

VTT has developed CatLignin technology for producing reactive lignin from pulp industry side streams currently used for energy production. Due to its superior reactivity, CatLignin is an ideal replacement for phenol in phenol formaldehyde resins and could become a new, high-value product for pulp mills. In addition, the CO2 footprint of lignin is only approximately 20% of the footprint of phenol. Resins have a significant impact on CO2 footprint of engineered wood products. For example in plywood, around half of CO2 footprint is caused by resin usage. Replacing phenol with lignin also reduces formaldehyde usage. To put this in context there are currently six million tons of phenol formaldehyde resins produced annually.

Senior VTT Scientist Hanne Wikberg says:”The suitability of lignin for a variety of applications has been investigated for decades, but only now we have found a way to use it as a phenol substitute in significant quantities in resins. VTT’s CatLignin technology represents a technological leap, offering new business opportunities to many industrial players”

This new material brings new business opportunities for the entire value chain, from lignin producers to adhesive and wood product manufacturers and end-users. In practice, this means pulp mills, adhesive, wood product and laminate manufacturers and their customers, such as kitchen cabinet and furniture brands.

The reactive lignin manufacturing technology can be integrated into pulp mills. Unlike existing technologies, the virtue of this process is the possibility to modify the lignin structure already at the pulp mill. Lignin structure can be tailored and therefore optimized specifically for each application.

Potential of CatLignin

  • The CatLignin material has potential as a substitute for a wide range of fossil-based chemicals in adhesive, rubber and plastic applications. Its anti-oxidative properties are expected to improve weather resistance reducing the need for fossil-based and expensive additives used today.
  • The CatLignin technology won the resource scarcity category in the New Tree 2017 competition in Finland on 1st February 2017 jointly with another VTT technology LigniOx concrete plasticizer solution. The competition jury – which consisted of experts from environmental and forestry sector together with societal and economic experts as well as Members of the Parliament of Finland – were particularly impressed by the societal importance and economic potential of the technology.

The Catlignin technology development is underway in a project funded by Tekes, the Finnish Funding Agency for Innovation, and VTT. This technology has already attracted a great deal of interest throughout the whole value chain and VTT is currently seeking partners for upscaling and commercialization of the technology.

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One comment

  1. The push by various “sanitary” authorities is to eliminate the use of UREA-formaldehyde resins since the reaction that polymerizes (cures) the adhesive is REVERSIBLE under high humidity and temperature conditions. The PHENOL-formaldehyde reaction is not reversible.
    Several things to be aware of:
    -if the manufacturer uses poorly formulated resin, there can be excess formaldehyde that is released.
    -urea-formaldehyde resin in US wood panel factories is generally used as a premixed product from a large adhesive supplier, made with the least amount of formaldehyde needed to cure the adhesive, and tested to meet a number of industry and government standards
    -urea-formaldehyde resin in factories overseas is often mixed in the factory to save cost, by workers with variable levels of education, and may or may not be tested to meet a standard. When you purchase your inexpensive particleboard products, please think about news reports of imported products where foreign government officials had been bribed to pass untested materials that were later found to be hazardous. There are more reasons than labor cost that US-Canadian-EU products cost more.
    -In the EU, the particleboard is often made with isocyanate adhesives. When properly made and cured, the only formaldehyde emitted comes from the wood when it is hot-pressed, and that dissipates within days of manufacture. Uncured adhesive reacts with moisture in the wood to completely cure it. However, manufacturing the adhesive uses isocyanates; the Bhopal, India industrial accident injured and killed people surrounding the plant. For workers, ioscyanate is toxic at much lower levels than formaldehyde (OSHA permissible exposure limits are 0.02 ppm for isocyanate vs 0.75 ppm for formaldehyde).

    Of all the wood adhesives, phenol-formaldehyde gives superior bonding and product durability in wet or dry conditions. It allows the use of small diameter forest thinnings as useful products, sequestering carbon dioxide for the (longer) lifetime of the product. There is no perfect technology or manufacturing method. Taking away this useful and durable adhesive reduces the choices to adhesives which have shorter lifespans, less resistance to moisture, or higher potential for harm in the event of accidental release.

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