NIR Spectral Imaging for the In-line Detection of Preservatives in Recovered Wood Dirk Maurus chat ∙ Jochen Aderhold ∙ Burkhard Plinke ∙ Peter Meinls chm idt Fraunhofer Institute for Wood Research – Wilhelm-Klauditz-Institut WKI, Bienroder Weg 54E, 38108 Braunschweig, Germany Workshop: Application of NIR spectroscopy for wood science and technology research, San Michele all‘Adige, Italy, April 15, 2014 © Fraunhofer WKI 1. Background and Objectives Growing need for wood in industry 8 Mt waste wood per year in Germany 66% combustion – 33% material recycling Particle board production Recycling of waste wood Use of waste wood, even contaminated Removal of hazardous substances Power generation by combustion of waste wood 2 © Fraunhofer WKI Mantau 2012, EPF 2012, BAV 2014 Manual sorting of waste wood Particle board made of waste wood 2. Experimental Search for fast analytical methods One promising technology: NIR spectroscopy Fast, robust, high resolution, comparatively inexpensive Conveyor belt: 3-15 m/min 4x300 W halogen lamps Innospec „SpectralEye NIR 2.2“ InGaAs detector: diffuse reflection 256 x 320 pixel (spectral x spatial) 1150-2200 [nm] R= 4 nm/Pixel ~ 40 000 € Pre-processing: standardization, spatial smoothing (median filter), spectral smoothing (Savitzky-Golay) NIR Hyperspectral Imaging System 3 © Fraunhofer WKI 3. Results Clear distinction of different wood preservatives Reflection spectra of pure active compounds Organic preservatives with large differences Inorganic preservatives without signals Tebuconazole Tolylfluanide PCP IPBC 4 © Fraunhofer WKI Lindane K-HDO natural pine wood 3. Results treated pine wood Comparison of pine wood treated with wood preservatives and natural pine wood Active agents: borax / boric acid Scoreplot of principal component analysis PC1 direct organic preservatives indirect inorganic preservatives NIR-analysis 5 © Fraunhofer WKI PC2 C.-L. So, et al., Wood Fiber Sci., 36 (3), 329-336, 2004. R. Feldhoff, et al., J. Near Infrared Spectrosc., 6, A171-A173, 1998. 3. Results Active agent: Tolylfluanide Discrimination of treated and natural wood Pine+MeOH Comparison of pine wood treated with organic wood preservatives and natural pine wood Pine untreated Pine + MeOH + Tolylfluanide PC1 PC2 6 © Fraunhofer WKI 3. Results Pine + H2O + boric salts Discrimination of wood treated with different wood preservatives Pine untreated Pine + MeOH + Tolylfluanide PC1 PC3 PC4 7 © Fraunhofer WKI 3. Results Influence of humidity? Discrimination of wood treated with different wood preservatives still successful dry wet Pine + H2O + boric salts Pine untreated Pine + MeOH + Tolylfluanide PC1 PC2 PC3 8 © Fraunhofer WKI Beech Spruce 3. Results Pine Ash Discrimination of wood species PC1 PC2 PC3 9 © Fraunhofer WKI 3. Results PCA Recovered Wood Samples 10B 8 PCP Lindane 9 H3BO3 CuCO3·Cu(OH)2 Propiconazole H3BO3 CuCO3·Cu(OH)2 10 © Fraunhofer WKI 1D H3BO3 CuCO3·Cu(OH)2 Lindane PCP Discrimination failed with PCA · Sample 8 · Sample 9 · Sample 1D · Sample 10B 3. Results Parafac Recovered Wood Samples 10B 8 PCP Lindane 9 11 1D H3BO3 CuCO3·Cu(OH)2 Propiconazole H3BO3 CuCO3·Cu(OH)2 © Fraunhofer WKI · Sample 8 · Sample 9 · Sample 1D · Sample 10B H3BO3 CuCO3·Cu(OH)2 Lindane PCP Better discrimination with Parafac 4. Conclusion Clear discrimination of pure, organic, active compounds for wood preservation Successful discrimination of… … wood treated with organic preservatives and untreated wood … wood treated with inorganic preservatives and untreated wood … different kinds of wood preservatives Investigation of the influence of… … humidity … wood species 12 © Fraunhofer WKI 5. Outlook Removal of wood treated with preservatives from waste wood with sorting plant? Investigation of the influence of… … particle size? … surface properties? … light source? Different pre-processing, multivariate analysis and classification methods? NIR-sorting plant Reduction of spectral noise? Extended spectral range Mid-Infrared? Quantitative analysis LODs? Legal limit for PCP: 3 mg/kg* ! Pneumatic ejection for separation 13 © Fraunhofer WKI * German ordinance on the management of waste wood, 2002. Thank you for your attention! Small-scale industrial pilot plant station Fraunhofer Institute for Wood Research in Braunschweig 14 © Fraunhofer WKI Gas chromatographs
© Copyright 2025 ExpyDoc
