Influence of Hemicellulose Extraction on Suitability for Oriented Strand Board (OSB) Production

Transcription

1 -Ac H Me H H CH Influence of Hemicellulose Extraction on Suitability for riented Strand Board (SB) Production H H H Rory H. Jara a Juan Paredes b Adriaan van Heiningen a Stephen Shaler b H -Ac H a Department of Chemical and Biological Engineering b Advanced Engineered Wood Composites Center -Ac

2 CH utline -Ac H Me H H Background bjectives Experimental procedures Results and discussions Conclusions H H H -Ac H H -Ac

3 -Ac H Me H H SB Process CH Wood components Background H Chemical composition and wood strength H H -Ac H H -Ac

4 Background SB Process C H M H e -A c H H H H H H -A c H -A c

5 Background -Ac H Me Logs H H Log Hauling and Sorting Ladding Debarking Stranding Screening Drying H CH Modified SB Process H H Hemicellulose Extraction Process -Ac H Sugar-based polymers Sugar-based chemicals Blending H Furfural Xylitol Ethanol Forming line Pressing Finishing line Shipping PERFRMANCE? -Ac

6 Background Wood Components C H M H Hardwood (% e o. d. wood) a Cellulose Lignina -A c a Hemicelluloses Ashb H H Lignin Softwood (% o. d. wood) Lignina H Cellulosea Xylan H H H -A Cellulose Hemicellulosesa Ashb a Sjostron, E., 99 b Rowell, R., 00 Glucomannan c H -A c (M. Åkerholm and L. Salmén, STFI 00) 6

7 Background Wood Components CH -Ac H Me H H H H Cellulose Glucomannan Lignin Lignin Xylan H -Ac (Lawoko et al. Biomacromolecules 6(6) 67-7, 00) H (Sweet et al. Holzforschung (999) -7) H -Ac 7

8 Background Chemical composition and wood strength -Ac H Me H H CH Molecular level depends on individual components of the cell wall H Cellulose greatest polymeric chain and higher DP Lignin is a nature s adhesive. Hydrophobic polymer. Cellulose and lignin are the main structural wood components. Hydrogen bonds are important for providing rigidity. H H Hemicelluloses are a series of carbohydrate molecules with lower DP than cellulose. They exhibit hydrogen bonding. -Ac Early degradation of hemicelluloses affect the wood strength (Curling at al., Forest Products Journal, Vol., No 78, 00) H H -Ac 8

9 Background -Ac Issues to be considered H Me H H CH Mechanical properties of SB must be maintained after hemicellulose extraction H The extraction process must minimize degradation of both cellulose and lignin H H -Ac H H -Ac 9

10 -Ac H Me H H CH H bjective Determine how specific variables in the SB strand extraction process (namely, ph, temperature, time and strand thickness) affect hemicellulose yields and characteristics of cellulose and lignin in the wood H H -Ac H H -Ac 0

11 H -Ac CH H H H Experimental H H H -Ac Procedure Me -Ac H

12 Experimental Procedures Wood material preparation C H M H e Red tree (hardwood) Maple -A H c Stranding process at AEWC H Center H Wood materialair-dried H H H -A c H -A c

13 Experimental Procedures Lab Extraction C H M H Water e Wood strands Ac H HASE-00 Modified Filtrate (Hemicellulose Extract) H Solid Residue (Extracted strands) H H -A 0 70ºC Temperature: c H Time: 90 min H -A c

14 WD CH Water Extraction Liquid Phase (Solid Determ.) Solid Phase -Ac H Weight Loss (ven Dried) DMC Extraction Me H H H Ash Content Hydrolysis (º, nd) Solid Content (Freeze Drying) Ash Content Klason Lignin Liquid Phase Centrifuge nd Hydrolysis Undissolved Material Acid Sol. Lignin HPAEC Analysis H H -Ac H HPAEC Analysis Klason Lignin Cellulose Hemicelluloses Cellulose Hemicelluloses H Chemical analysis procedure -Ac

15 Experimental Procedures -Ac H Yield sp (%) = Yield lp Yield Determination Me (%) = H H CH solid residue (o.d.) after extraction wood (o.d.) before extraction H S.C. fd Total weight extract wood (o.d.) before extraction H H -Ac H *00 *00 H -Ac

16 Results CH -Ac H Me H H Water extraction yield Mass Balance H SB panels and physical/mechanical properties H H -Ac H H -Ac 6

17 Results: Water extraction yield Water Extraction - Yield vs Temperature CH Yield (mg/g wood) Ac H H Me H H H H -Ac Temperature (ºC) H H From solid - min From solid - 90 min From solid - min from liquid - min From liquid - 90 min From liquid - min -Ac 7

18 Results: Water extraction yield -Ac H Me H H CH Proposed for verend and Chornet, 987) R Where, = t t: Time (minutes) Severity Factor (Ro) H exp T: Temperature (ºC) T[ o C] 00.7 H H -Ac H H -Ac 8

19 Results: Water extraction yield Water Extraction - Yield vs Temperature CH Yield (mg/g wood) Ac H H Me H H H H -Ac Severity Factor (Ro) H H From solid From liquid -Ac 9

20 Results: Water extraction yield CH Severity Effect on ph Extraction ph Ac H ph Me H H H R = Yield (from s.p.) H H R = H -Ac Severity Factor (log(ro)) H -Ac Yield (s.p., mg/g wood o.d.) 0

21 Results: Mass balance CH Lignin removed from wood Lignin removed ( % ) Ac H Me H H Precipitated Lignin (From Liquid) H Klason Lignin (From Liquid) Acid Soluble Lignin (From Liquid) Total Lignin (From Liquid) Total Lignin (From Solid) H H H -Ac Severity Factor (Log Ro) H -Ac

22 Results: Mass balance Carbohydrate content (% on original sugar) Ac H H Me CH Carbohydrates Mass Balance - Liquid Phase H H H H -Ac Severity Factor (Log Ro) H Arabinan Galactan Xylan Mannan Cellulose H -Ac

23 Results: Mass balance Carbohydrate content (% on original sugar) Ac H H Me CH Carbohydrates Mass Balance - Solid Phase H H H H H -Ac Severity Factor (Log Ro) H Arabinan Galactan Xylan Mannan -Ac

24 Results: Mass balance CH Mass Balance Hemicelluloses Sugar (mg/g wood o.d.) Ac H H Me H H H H -Ac H Severity Factor (Log(Ro)) H Arabinan-L.P. Galactan-L.P. Xylan-L.P. Mannan-L.P. Arabinan-S.P. Galactan-S.P. Xylan-S.P. Mannan-S.P. -Ac

25 Results: SB Panels Manufacture of SB Panels CH Pressure Indicator Flow Control Valve Heat Exchanger Circulation Pump Heat Exchanger Cooling Water -Ac H Me Vessel H H H Vessel H Rupture Disk Thermal Sensor (RTD) Thermal Sensors (RTD) Drain Valve Real Time Sampling H Pressure Release Valve Pressure Safety Switch Dispersion Weight Basket Inside (To hold wood material) Insulation -Ac H Conditions: Temperature: 60ºC Time: 90 min Batch: 00 grs. (Preheating: 0 min) L / S: 6 H -Ac Water extraction Pilot scale

26 Results: SB Panels Manufacture of SB Panels CH -Ac H Me H H Panel manufacturing was done at AEWC Center following internal procedures: Weight:.8 kg H Adhesive: pdmi, % o.d.w. Density: 8pcf, at 0% MC H H -Ac H H -Ac 6

27 Results: SB Panels Physical Properties CH -Ac H Me H H Tests were done following ASTM D 07 specifications. Moisture Content (%) Moisture Content Behavior H H H H -Ac Control SF-. SF-.8 Material Source H Conditioned Hours Hours -Ac 7

28 Thickness Swell Behavior Thickness Swell (%) Ac H Me H H CH H Control SF-. SF-.8 Material Source Water Absortion (%) H H Hours Hours Water Absortion Behavior -Ac H H Control SF-. SF-.8 Hours Hours Material Source -Ac 8

29 Results: SB Panels Mechanical Properties CH -Ac H Me H H Tests were done following ASTM D 07 specifications. Load Factors H Mechanical Properties H H H -Ac MR (psi) ME (kpsi) SPL (psi) IB (psi) Control SF-. SF-.8 Material Source H -Ac 9

30 -Ac H Me H H CH Extraction with pure water Conclusions H Degradation of cellulose is not significant Xylan contribute significantly more to the total hemicellulose yield. H H Continued hydrolysis of carbohydrates Further research is necessary to understand changes in physical and mechanical properties of SB -Ac H H -Ac 0

31 H -Ac CH -Ac Me H H H H H H H -Ac

32 Results -Ac Cellulose H H Me Hemicellulose Mass Balance H CH H = [Glucan Mannan/.7]/(wood weight) = Total Sugar/(wood weight) - Cellulose H Xylan H = [Xylose*(/0)+UA*0.6*(/76)] -Ac H H -Ac

33 -Ac H SPL Load (Stress) Me CH H H H H ME MR H -Ac H Deflection (Strain) MR: Modulus of Rupture (Maximum Load) ME: Modulus of Elasticity SPL: Stress at Proportional Limit H -Ac