From Black Liquor to Green Material: Enzymatic Valorization of Pulp Industry Byproducts
Kraft lignin (byproduct of the Kraft cooking process) was isolated from the black liquor to study and optimize the experimental conditions for its enzymatic polymerization. Lignin polymerization was used as binder in the manufacture of medium density fiberboards (MDF) with no synthetic adhesives. The objective of this study was to produce MDF totally free of adhesives, where wood fibers were bonded together due solely to the bonds created by enzymatic polymerization of the lignin in the fibers. The addition of Kraft lignin to the wood fibers before the MDF manufacture significantly improved the mechanical and dimensional properties of the board. Some of the produced pilot-scale MDF have properties that meet the standards to be marketed. In this way, a completely free MDF synthetic adhesives were obtained valuing simultaneously a byproduct from the pulp industry available worldwide on a large scale.
KeywordsGreen material Black liquor Enzymatic valorization Pulp byproduct Polymerization
Ence (Spain) is gratefully acknowledged for supplying the black liquor. Novozymes (Denmark) is also kindly acknowledged for supplying the laccase from M. thermophila. This work was supported by Xunta de Galicia (projects 09TMT012E and EM2014/041), ERDF Funds and Ministry of Science and Innovation (project CTQ2009-13651) and by Fundação para a Ciência e a Tecnologia – Portugal through grant POP-QREN BD 42684/2008.
- ANSI (2002) ANSI A.208.2-2002. Medium Density Fiberboard (MDF) for interior application. American National Standard Institute, Washington DC, USAGoogle Scholar
- EN (2010) EN 622-5:2010. Fibreboards specifications. Part 5: Requirements for dry process boards (MDF), European Standards, European Commission, Brussels, BelgiumGoogle Scholar
- Faix O (1992) Fourier transform infrared spectroscopy. In: Methods in lignin chemistry. Springer, Heidelberg, pp 83–109Google Scholar
- Kalami S, Arefmanesh M, Master E, Nejad M (2017) Replacing 100% of phenol in phenolic adhesive formulations with lignin. J Appl Polym Sci 134Google Scholar
- Lora J (2008) Industrial commercial lignins: sources, properties and applications. In: Belgacem MN, Gandini A (eds) Monomers, polymers and composites from renewable resources. Elsevier, Amsterdam, pp 225–241Google Scholar
- Pye EK (2008) Industrial lignin production and applications. In: Biorefineries-industrial processes and products: status quo and future directions. pp 165–200Google Scholar
- van de Pas D, Hickson A, Donaldson L, Lloyd-Jones G, Tamminen T, Fernyhough A, Mattinen M-L (2011) Characterization of fractionated lignins polymerized by fungal laccases. BioResources 6:1105–1121Google Scholar