Session 3 ic2011 migneault

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Session 3 ic2011 migneault

  1. 1. 2011‐08‐01PULP AND PAPER SLUDGE AS ABINDER AND FORMALDEHYDESCAVENGER IN MEDIUM- MEDIUM-DENSITY FIBERBOARDSébastien Migneault (Laval University)Ahmed Koubaa (University of Québec in Abitibi-Témiscamingue)Bernard Riedl (Laval University)Hamid Nadji (Laval University) j ( y)James Deng (FPInnovations - Forintek Division)Tony Zhang (FPInnovations - Forintek Division) FPS 65th International Convention, Portland OR, June 2011 BACKGROUND 1
  2. 2. 2011‐08‐01PULP AND PAPER SLUDGE Primary sludge (PS): solid matter removed in primary water treatment process PS contains wood fibers, inorganics, others Secondary sludge (SS): solid matter obtained after secondary treatment, or biological treatment Main organic components of SS: microbial extracellular polymeric substances (EPS), non- (EPS) non biodegraded materials, microbial cell biomass, others (Bitton 2005) EPS is rich in proteinsADHESIVES FOR MDF Urea-formaldehyde (UF) resin widely used for medium-density fiberboard (MDF) y ( ) Increasing demand for environmentally friendly products Severe legal restrictions on formaldehyde (HCHO) emissions from wood products Wood composites were glued with protein- protein based adhesives in early 1900s until 1960s SS contains proteins… 2
  3. 3. 2011‐08‐01ADHESIVE PROPERTIES OF SS Pulp 100%PS 80%PS+20%SS 60%PS+40%SS (Zerhouni 2010)ADHESIVE PROPERTIES OF SS (Geng et al 207b) 3
  4. 4. 2011‐08‐01 PREVIOUS STUDIES  Recent studies have proposed recycling PS as a fiber source for wood-based panels p Davis et al 2003 Geng et al 2006, 2007a Migneault et al 2010 Taramian et al 2007  Minimum industry quality requirements are often satisfied  Always a reduction in panel quality when sludge is added in panels PREVIOUS STUDIES 2.0 50 Pa) Pa) 40 Bending MOR (MPIB strength (MP 1.5 R² = 0.8367 30 1.0 20 0.5 10 R² = 0.8445 0.0 0 0 10 20 30 40 0 10 20 30 40 Ash content (%) Ash content (%) (Migneault et al 2010) 4
  5. 5. 2011‐08‐01 OBJECTIVESOBJECTIVES Study the adhesive properties of SS Evaluate the potential of SS as a bonding agent and HCHO scavenger in MDF Better understand the relationship between sludge characteristics and panel properties 5
  6. 6. 2011‐08‐01 MATERIAL AND METHODSSLUDGE COLLECTION, REFINING,AND CHARACTERIZATION PS and SS collected from 3 pulp & paper mills 1. Thermomechanical (TMP) ( ) 2. Chemico-thermomechanical (CTMP) 3. KRAFT Production based on chips from commercial eastern softwood species : spruce, balsam fir, pine (SFP) Sludge mixed at three SS:PS ratio : 1:9, 2:8, 3:7 corresponding to 10% SS, 20% SS, 30% SS content SS SS Refined in TMP disc refiner and dried to 3% MC Sludge characterized for chemical composition and buffering capacity 6
  7. 7. 2011‐08‐01BONDING PROPERTIES OF SUDGE Sludge samples were hot-pressed and characterized to evaluate the adhesive properties of SS Binderless sludge panels (no fibers, no resin, only PS and SS) Factorial plan: the 3 pulping processes and the 3 SS:PS ratios Density of 1100 kg/m³ and 210°C for 8 minutes ( p (optimized in Geng et al. 2006) g ) Samples tested for internal bond (IB) strength and thickness swell (TS) Bonding mechanisms were studied using FTIR, XPS and chemical composition of sludgeMDF PROCESSING ANDCHARACRTERIZATION Panels processing Sludge and wood fibers (1:1), UF resin, wax (1:1) resin Fibers: TMP white birch (underutilized species) Sludge from 2 mills: TMP, CTMP (KRAFT rejected) UF content reduced from 12% to 8% and replaced by SS as a binder (5%SS to 15%SS) Panel characterization Internal bond (IB) strength (ASTM D 1037) Thickness swell (ASTM D 1037) Formaldehyde (HCHO) emissions (ASTM D 5582) 7
  8. 8. 2011‐08‐01RESULTSPart 1: Bonding properties of sludge(binderless sludge panels)PICTURES OF SLUDGE Photos of refined and dried sludge (15X)TMP CTMP KRAFT 8
  9. 9. 2011‐08‐01 BINDERLESS SLUDGE SAMPLES 2.0 es ative propertie TMP 1.8 CTMP IB 1.5 KRAFT 1.3 1.0Rela 0.8 TS 0.5 0 10 20 30 40 SS content (%) CORRELATIONS 2.0 2.0 TMP TMP 1.6 CTMP 1.6 CTMP IB strenght (MPa) IB strenght (MPa) KRAFT KRAFT 1.2 1.2 0.8 0.8 0.4 04 0.4 04 R R² = 0.7473 R² = 0 9115 0.9115 0.0 0.0 0.0 0.3 0.6 0.9 1.2 1.5 20 23 26 29 32 Nitrogen content (%) Lignin content (%) 9
  10. 10. 2011‐08‐01 XPS BEFORE vs. AFTER PRESSINGHigh resolution carbon peakC1 : Unoxidized carbon atom (ie C-C, C-H), mainly lignin and extractivesC2 : Carbon with one bonded oxygen (ie C-O), mainly carbohydratesC3 : Carbon with two bonds with oxygen (ie O C O C O) mainly carbohydrates O-C-O, C=O), C1 (69%) C1 (51%) C2 (24%) C2 (39%) IntensityIntensity C3 (4,0%) C3 (7,1%) I 283 285 287 289 283 285 287 289 Binding energy (eV) Binding energy (eV) RESULTS Part 2: Medium-density fiberboards (MDF) 10
  11. 11. 2011‐08‐01HCHO EMISSION LEVELS 0.35 0.30HCHO (µg/L) 0.25 0.20 0.15 0.10 0.05 0.00 Control TMP CTMP Control TMP CTMP Low SS High SS Normal UF Reduced UFIB STRENGTH 2.0 Pa) IB strength (MP 1.6 16 1.2 0.8 0.4 B 0.0 Control TMP CTMP Control TMP CTMP Low SS High SS Normal UF Reduced UF 11
  12. 12. 2011‐08‐01THICKNESS SWELL 30Thickness swell (%) 25 20 15 10 5 0 Control TMP CTMP Control TMP CTMP Low SS High SS Normal UF Reduced UFPH AND BUFFER CAPACITY10 Alkaline buffering capacity 8 (mmol per 100 g sample) pH 5.8 5.8 6 5.2 4.9 3.9 4 2 0 Low High Low High Birch TMP CTMP fibers 12
  13. 13. 2011‐08‐01CONCLUSIONS PS contains fibers SS has adhesive properties SS can be used as HCHO scavenger in MDF The bonding effect of SS in MDF (i.e. when combined with UF) was lower then expected because of high pH and buffering capacity (need for further research) SS negatively impacted panels TS (need for further research) Thank you Questions? 13

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