FBRI Theme II Extraction and Residual Solids Utilization David J. - - PowerPoint PPT Presentation

FBRI Theme II Extraction and Residual Solids Utilization

David J. Neivandt

Theme II Objectives

• To generate new knowledge needed for

selective and controlled extraction of hemicellulose from forest biomass

• To understand the effect of extraction on

wood properties and resultant wood products, in addition to downstream pulp, fuels, chemicals and biomaterials

Selective Extraction Processes

• Extraction of hemicelluloses from hardwood
• Prehydrolysis of phenyl glycosidic bonds in

wood chips

• Adsorption of extracted and modified

hemicelluloses on pulps

Hemicellulose Extraction of Mixed Southern Hardwood with Pure Water

Wood : Southern hardwood mixture (SHM) (Extractives-free, 2mm) Extractor : Modified Dionex ASE-100 Time : 0 - 500 minutes Temp. : 150 °C Pressure : ~150 atm. Solvent : water L/W : ~4L/od kg Sefik Tunc, PhD candidate

Extraction Yields Extraction Yields

4 8 12 16 20 24 100 200 300 400 500 Time, minute g/100g o.d wood

Total Lignin-free extraction yield from wood Total Lignin-free yield found in liquid Xylan removed from wood Xylan found in liquid Glucomannan removed from wood Glucomannan found in liquid Cellulose found in liquid Cellulose removed from wood

Water extraction of SHM T : 150 °C Lignin-free extraction yield increases with increasing time Cellulose stayed intact

• Substantial hemicellulose dissolution, deacetylation and

uronic anhydride removal with increasing time

• Cellulose stays intact during dissolution
• Xylan remaining in wood is highly acetylated and uronic

acid content decreases with increasing time

• No significant amount of furfural is generated
• Xylan dissolves as oligosaccharides and then slowly

depolymerizes to xylose at longer extraction times

• Dissolved oligosaccharides are initially highly acetylated;

deacetylation takes place subsequently

• The acidity of the extract increases with time

Conclusions Conclusions

Kinetics of Degradation of Lignin-Carbohydrate Model Compounds

Aim : To study the effect of wood processing conditions on the cleavage of Lignin-Carbohydrate Bonds. (Special case Phenyl- glycoside) Reaction : Analysis Approach :

a) Disappearance of Phenyl glucoside (PG) b) Formation of Phenol and Glucose

Sagar Deshpande, MSc candidate

Case 1 : Analysis of PG left and Glucose formed by GC-MS. Sample preparation: Reduction Acetylation Analysis of Alditol Acetates.

Inositol used as Internal Standard (IS)

Chromatogram from GC-MS: Reaction conditions: 90C – 5 hours , Acidic nature ( 0.05M HCl )

Methodology

10 20 30 40 50 60 70 80 90 100

145 150 155 160 165 170 175 Temperature ( C) % of PG cleaved 1 2 3 4 5 6 7 8 9 10 11 12 13 Acetic Acid (mg/ml)

% PG cleaved Concentration of Acetic Acid

Case 2 : Analysis of Phenol produced by GC-MS Approach: Direct two phase extraction from water phase with Dichloromethane and analysis of the latter phase by GC-MS.

Guaiacol used as Internal Standard (IS)

Chromatogram from GC-MS: Reaction conditions: 90C – 5 hours , Acidic nature ( 0.05M HCl )

20 30 40 50 60 70 80 90 100 110 60 70 80 90 100 110 120 130 Temperature ( C) % of PG cleaved

Adsorption of Extracted and Modified Hemicelluloses on Pulps

0.00 5.00 10.00 15.00 20.00 25.00 30.00 500 1000 1500 2000 2500 3000 Time (min) Adsorption yield (g/100g pulp) 100C 90C 70C 50C 25C

Adsorption Kinetics Xiaowen Chen, PhD candidate

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.02 0.04 0.06 0.08 0.1 0.12 Ce(extracts g/ ml of solution) Qe(extracts g/g of pulp)

experimental data Langmuir Model Freunlich model 70C 50C 90C

Adsorption Isotherm

Influence of Hot Water Extraction

• n OSB Behavior
• Objective: Determine the influence of hot water

extraction on physical, mechanical, and microstructure properties of wood strands and the subsequent behavior of OSB panels made from the modified wood

• Wood Species: Red Maple
• Extraction Conditions: 160 C (50 minute

temperature ramp following by 45 or 90 minutes at temperature). Juan Parades, PhD candidate

Results - Extraction Process

• The severity factor (extraction time, Ro) and Tree

source significantly influenced weight loss

• Strand thickness had no significant impact on

weight loss.

2.80 3.54 3.81 A B C 0.025” 0.035” 0.045” Ro Tree Strand Thickness

Ro_2.8 Ro_3.5 4 Ro_3.8 1

Results - Wood Modification

• Cellulose crystallinity and size

exhibited a significant increase.

• The intra cell wall porosity

was shown to be approx. 12% higher.

• Cell wall damage was shown

to occur as evidenced by pitting.

• A significant increase in liquid

penetration rate was exhibited.

Surface evaluation

Low magnification High magnification Control Ro_ 3.54 Ro_ 3.81

Results - OSB Panels

• The sorption curves of extracted wood strands

were strongly lowered compared to control material.

• Dimensional stability in air of OSB panels were

enhanced after hemicellulose removal.

• The flexural strength (MOR) was similar for

control and Ro_3.54 but exhibited a significant decrease at Ro_3.81 (cell wall damage).

• The internal bond in dry and wet conditions from

both extractions were significantly lower (overpenetration).

4 8 1 2 1 6 20 25 50 75 1 00 Desorption Control Resorption Control Desorption Nonhemicellulose Resorption Nonhemicellulose

Biomodification of Wood

• Breakdown of wood cell

wall

• Fungi involved are

filamentous, capable of penetrating and colonizing wood cells

• Utilize cell wall

constituents as a nutrient source

63x Microscopy - confocal

Trametes versicolor, in Pine wood

Brown Rot Wood Decay Fungi

• Cause an extensive, rapid reduction in cellulose DP 10000

to 250

• Capable of converting cellulose into simple sugars
• Primary group responsible for degradation of wood

products and recycling of carbon and nutrients in northern ecosystems

• Bioremediation of pollutants: dichlorophenol,

pentachlorophenol, heavy metals

• Potential utilization in bioprocessing of lignocellulose and

production of ethanol and value added bio-based materials

• 1 faculty member, 2 research associates, 3 graduate

students, 3 undergraduates

• Basic biodegradation and biomodification

mechanisms

• Enzymatic and non-enzymatic processes involved in

lignocellulose modification

• Use of X-ray diffraction, NIR, and MBMS to follow

lignin and cellulose modifications

Biological Degradation Overview

Caitlin Howel, MS candidate

Identification of Forest Bio-Products through Near-Infrared Spectroscopy

• Use near-infrared spectroscopy (NIRS) to identify woody

biomass components

• Advantage to using NIRS:

– No need for sample preparation – NIR does not interfere with sample composition

• Ultimately can be used in-process-line in the forest bio-

products process

Original Spectra of Glucomannan Aqueous Solutions Original Wood Chip Spectra Glucomannan Spectra after Subtracting the Water

Results after a Calibration

(near) Future Work

• Create a vast near-IR spectral database of woody biomass

processing streams

– Create liquid solutions for both hardwood and softwood extract components in the laboratory and acquire their spectra – Note any deviation of the NIR spectra due to change in viscosity, surface texture, etc in the database

• Perform a multivariate calibration of spectra with the partial

least squares method (PLS)

• Test calibration (validate) by scanning liquid extracts that

come directly from the forest bio-products extraction process (van Heiningen’s lab)

Surface Modification of WPCs Surface Modification of WPCs for for Enhanced Adhesion Enhanced Adhesion

• For structural applications wood-polymer composites require

lamination

• Given the inert nature of the polyolefin comprising ~50% of the

WPC, gluing WPCs typically leads to low shear strength

• Surface modification of WPCs prior to adhesion may lead to

improved shear strength

• To date have investigated chromic acid, sanded (P60, P220),

flame, heat, water, water-flame and flame-water treatments. Gloria Oporto, PhD candidate

97

• 6

1 00 81 87 31 67 30

• 20

20 40 60 80 100 120 Control Chrom ic acid P 60 P 200 Flame Heat Water Water- flam e Flame- water Treatment Increase in shear strength from control (%)

Treatment Effect on Shear Strength

1 2 3 4 5 6 Control Chrom ic acid P 60 P 220 Flam e Heat Water Water- flam e Flam e- water Treatment γs^AB (mJ/m^2) 1 2 3 4 5 6 7 8 9 10 Shear strength (MPa)

Using Diodometane, Water receding contact angle and Ethylene glycol Shear strength

Correlation Between Surface Energy and Shear Stress

Fabrication and Testing of Biobased and Synthetic Sheet Molding Compound

Ryan Mills, PhD candidate

• Can biobased reinforcing fiber be employed in SMC

with acceptable mechanical and durability properties?

• Need to understand the surface chemistry of the biobased

fibers in order to compatibilize with the matix

• Inverse Gas Chromotography (IGC) is being employed

to determine surface energy and polar nature

• Hygrothermal treatment of the resultant composite is

used to simulate aging

• Dynamic mechanical thermal analysis of composite

3 minute cure at 1000psi and 150 Celsius at the AEWC Compounding of SMC done at AOC resins

3 Point bending testing from -50˚C to 250˚C

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 0.11

• 30
• 5

20 45 70 95 120 145 170 195 220 245

Temperature (C) Tan Delta UPE PE COOHME PVAc

PVOH reference 3 hr age 14hr age 168 hr age 336 hr age 1032 hr age

Glass transitions of various components in traditional SMC as a function of aging time

• Natural fibers are very hydrophilic; whereas, the polyester matrix is hydrophobic. Therefore

need sizing agents

• Natural fibers typically have lower Young’s modulus and other mechanical properties as

compared to glass reinforcements; therefore, the interaction between the fibers and matrix must be maximized.

• The acid characteristics of the natural fibers are higher then that of the glass fibers indicating a

better interaction between natural fibers and the matrix than with the glass fibers.

• In general, the cost of natural fibers is much less then glass.

• Delignify hemicelluloses from both hardwood and

softwood

• Hydrolyze delignified hemicelluloses to component

sugars

• Develop chemistry for high-value chemicals from the

sugars (e.g., itaconic acid)

• Accomplish goals using green chemistry

Chemistry of Hemicelluloses

LeRae Graham, PhD candidate Dylan Montgomery, Undergradate

Can Delignification Be Effected Enzymatically?

Laccase, from white rot fungi Three-Cu site reduces O2 to H2O One-Cu site oxidizes phenolics Capable of depolymerizing lignin

Computer Docking of Lignin-Carbohydrate Models

Docked Aromatic In Docked Sugar In Ebind = -8.6 kcal/mol Ebind = -7.6 kcal/mol Note: stacking of sugar with Phe265; H-bonding to His458

• Commercially available birch xylan was used as
• ur hemicellulose
• Xylan suspension sonicated 1 hr
• Xylanase from Trichoderma viride
• pH 4.5, 30º, 24 hr
• Analysis by HPLC-MS, chemical ionization
• Yield: 86% by weight

Given one unreactive branched residue in ten, this is close to theoretical yield

Preliminary attempts to delignify birch xylan:

• Lignin detected by UV absorption of aromatics at

about 270 nm

• Reacted with H2

O2 , hν, pH 12, 1 hr

• 90% reduction in intensity of aromatic UV

absorption

• No organic products from aromatics detectable

by GC-MS; only product appears to be CO2

• Some hydrolysis of hemicellulose occurs,

liberating xylose

SFS of the Model Cellulose & Lignin Substrates

• Sum Frequency Spectroscopy, provides surface specific

vibrational spectra

• Provides detailed orientation and conformational

information of interfacial species

• In conjunction with traditional spectroscopies and

microscopies, will enable detailed characterization of cellulose surface pre and post modification

• Must develop a cellulose substrate suitable for SFS and
• ther techniques

Lei Li, PhD candidate

Theory Developed of SF Generation from Model Cellulose Substrates

Cellulose Gold Air/Solution

100 200 300 400 500 0.6 0.8 1.2 1.4 1.6 1.8

Dominant Periodicity = 246 nm Minor Periodicities = 276 nm, 2.252 μm

d (nm) SF Intensity (arb)

Model Complete, Currently Being Verified

• Have created both cellulose and lignin films
• rms roughness on the order of nm’s
• film thickness in the correct region (~120 nm)
• Issue with stability of films in water currently being

addressed