Our Industry’s Need to Refine Lignin Prior to Use in a Way Similar to Crude C. Cui, R. Sun & D. S. Argyropoulos Departments of Chemistry and Forest Biomaterials North Carolina State University, Raleigh, NC USA Department of Chemistry & Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Saudi Arabia. COST Action FP1105 Principles of cell wall assembly – Understanding and Implementation. May 8-9; 2014 Coimbra, Portugal

Our Industry’s Need to Refine Lignin Prior to Use in a Way Similar to Crude Cui, C., Sun, R.,& Argyropoulos, D. S. ; Fractional Precipitation of Softwood Kraft Lignin; Isolation of a Narrow Fractions Common to a Variety of Lignins” ACS Sustainable Chem. Eng., Articles ASAP; Publication Date: January 30, 2014 DOI: /sc400545d Argyropoulos, D. S. US Pub. No. : US 2013/ A1, Pub Date : Oct.3 rd 2013, US Patent Application No,61/601,181, Filed Feb

n Kraft lignin is a by-product of the paper industry; n The Kraft process is continuously adjusted/monitored/modified with the aim to produce paper not lignin; n Manufacturing/Seasonal/Geographical & other variations; by definition offer a Heterogeneous/Polydisperse/Irregular & notoriously irreproducible material. Kraft Lignin; A Valuable Resource

What are key questions/objectives that will significantly (but not incrementally) advance the field? If Kraft lignin is to be used as a valuable chemical resource is it possible to have it Refined & Upgraded to the level of becoming a reliable commodity chemical? Is it possible to arrive at functional kraft lignin polymers/phenolic precursors - of consistent quality & specs on a daily basis? - of functionality that defines it as a polyol ? - of low Mol. Wt Distribution that defines it as polymeric precursor of defined/controlled reactivity ?

Objectives /Rationale To develop a technology that allows for some control of the extreme heterogeneity of lignin To arrive at technical lignins with consistent chemical properties To tune and control the Functionality of technical lignins Toward Arriving at Fractions of Softwood Kraft Lignin that are Identical in Composition Irrespective of its Manufacturing Details

Selection of Two Different Sources Lignin Source Wood Source Cook Type Pulp Type Aim Target Kappa H FactorActive Alkali Low H Factor Low Delignification Intensity Southern Pine Kamyr Continuous Saturated Pulp & Lignin Precipitaion % High H Factor Low Delignification Intensity Southern Pine Kamyr Continuous Bleachable Grade Undisclosed

AIKL Kraft Lignin (100 g) Supernatant (I) Solid 1. Stirred in 1000 mL acetone for 6 h; 2. Filtration. Addition of 250 mL Hexanes Supernatant (II) ASKL 250mLHex Discarded Solid Supernatant (III) ASKL Purified (I) of Uniform Composition Irrespective of its Origin ASKL Purified (I) of Uniform Composition Irrespective of its Origin Addition of 750 mL Hexanes 1.Solvent evaporation; 2.Re-dissolved in 200 mL of acetone. Acetone solution ASKL Purified (II) 1.Addition of 800 of hexanes; 2.Filtration Fractionation Scheme

Superimposed GPC Profiles of Two Softwood Kraft Lignins High H Factor Lignin, 1200-KL Low H Factor Lignin, 600-KL Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Superimposed GPC Profiles of the AIKLs of Indulin AT and Domtar Kraft Lignins High H Factor Lignin, 1200-AIKL Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Superimposed GPC Profiles of the AIKLs of the two Kraft Lignins The long tailing apparent in AIKL of technical lignins contributes to extreme heterogeneity, increased functionality causing stochastic & irreproducible characteristics High H Factor Lignin, 1200-AIKL Low H Factor Lignin, 600-AIKL

The Case of Kraft Lignin 1 An Intensively pulped softwood wood aimed at creating Bleachable grade pulp (Very Low Lignin content). H Factor 1200

Superimposed GPC Profiles of the Whole Kraft Lignin 1 and its Fractions High H Factor Lignin, 1200-KL Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

High H Factor Lignin, 1200-AIKL High H Factor Lignin, 1200-KL Superimposed GPC Profiles of the Whole Kraft Lignin 1 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

High H Factor Lignin, 1200-KL High H Factor Lignin, 1200-AIKL High H Factor Lignin, mLHex Superimposed GPC Profiles of the Whole Kraft Lignin 1 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

High H Factor Lignin, 1200-AIKL High H Factor Lignin, 1200-KL High H Factor Lignin, mLHex High H Factor Lignin, 1200-ASKL(I) Superimposed GPC Profiles of the Whole Kraft Lignin 1 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

High H Factor Lignin, 1200-AIKL High H Factor Lignin, 1200-KL High H Factor Lignin, mLHex High H Factor Lignin, 1200-ASKL(I) High H Factor Lignin, 1200-ASKL(II) Superimposed GPC Profiles of the Whole Kraft Lignin 1 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Superimposed GPC Profiles of the Whole Domtar kraft Lignin and its Fractions High H Factor Lignin, 1200-AIKL High H Factor Lignin, 1200-KL High H Factor Lignin, mLHex High H Factor Lignin, 1200-ASKL(I) High H Factor Lignin, 1200-ASKL(II) Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

The Case of Kraft Lignin 2 An Low Intensity pulped softwood wood aimed at creating Liner board grade pulp, (High Lignin content). H Factor 600

Low H Factor Lignin, 600-KL Superimposed GPC Profiles of the Whole Kraft Lignin 2 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Low H Factor Lignin, 600-KL Low H Factor Lignin, 600-AIKL Superimposed GPC Profiles of the Whole Kraft Lignin 2 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Low H Factor Lignin, 600-KL Low H Factor Lignin, 600-AIKL Low H Factor Lignin, mLHex Superimposed GPC Profiles of the Whole Kraft Lignin 2 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Low H Factor Lignin, 600-KL Low H Factor Lignin, 600-AIKL Low H Factor Lignin, mLHex Low H Factor Lignin, 600-ASKL(I) Superimposed GPC Profiles of the Whole Kraft Lignin 2 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Low H Factor Lignin, 600-KL Low H Factor Lignin, 600-AIKL Low H Factor Lignin, mLHex Low H Factor Lignin, 600-ASKL(I) Low H Factor Lignin, 600-ASKL(II) Superimposed GPC Profiles of the Whole Kraft Lignin 2 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Low H Factor Lignin, 600-KL Low H Factor Lignin, 600-AIKL Low H Factor Lignin, mLHex Low H Factor Lignin, 600-ASKL(I) Low H Factor Lignin, 600-ASKL(II) Superimposed GPC Profiles of the Whole Kraft Lignin 2 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Low H Factor Lignin, 600-KL Low H Factor Lignin, 600-AIKL Low H Factor Lignin, mLHex Low H Factor Lignin, 600-ASKL(I) Low H Factor Lignin, 600-ASKL(II) Superimposed GPC Profiles of the Whole Kraft Lignin 2 and its Fractions Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Comparison of GPC Profiles of ASKL Purified (I) Emerging form Kraft Lignins 1 & 2 High H Factor Lignin, 1200-KL Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

MnMwPDI Low H Factor Lignin ASKL Purified (I) High H Factor Lignin ASKL Purified (I) High H Factor Lignin,1200-ASKL(I) Low H Factor Lignin,600-ASKL(I) Comparison of GPC Profiles of ASKL Purified (I) Emerging form Kraft Lignins 1 & 2 Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

OH Content Comparison for Fraction P(I) from the two Kraft Lignins Low H Factor Lignin, 600-ASKL P(I) High H Factor Lignin, 1200-ASKL P(I)

Low H Factor Lignin, 600-ASKL P(I) High H Factor Lignin, 1200-ASKL P(I) OH Content Comparison for Fraction P(I) from the two Kraft Lignins

Low H Factor Lignin, 600-ASKL P(I) High H Factor Lignin, 1200-ASKL P(I) OH Content Comparison for Fraction P(I) from the two Kraft Lignins

Low H Factor Lignin, 600-ASKL P(I) High H Factor Lignin, 1200-ASKL P(I) OH Content Comparison for Fraction P(I) from the two Kraft Lignins

Low H Factor Lignin, 600-ASKL P(I) High H Factor Lignin, 1200-ASKL P(I) OH Content Comparison for Fraction P(I) from the two Kraft Lignins Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Comparison of Molecular Weight Characteristics Low H Factor Lignin, 600-ASKL P(I) High H Factor Lignin, 1200-ASKL P(I)

Low H Factor Lignin, 600-ASKL P(I) High H Factor Lignin, 1200-ASKL P(I) Comparison of Molecular Weight Characteristics Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Fractional Precipitation offers a Continuum of Fractions of Lower Mw & of Progressively Narrow Distribution Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Linear Relations of Vital Functional Groups and Volume Fractions of Hexanes are apparent Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Linear Relations of Vital Functional Groups and Mn are apparent Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

By Creating Physical Mixtures of Three Different Softwood Kraft Lignins one is able to Isolate a Common Narrow Fraction Cui, C., Sun, R.,& Argyropoulos, D. S. ; ACS Sustainable Chem. Eng., ASAP Publication Date (Web): January 30, 2014 DOI: /sc400545d

Outcomes & Opportunities For the first time it is demonstrated that kraft Lignin can be refined. -To distinct, reproducible “cuts” -Such “cuts” are common to various Kraft lignins irrespective of their manufacturing details. -A novel route to lignin upgrading now becomes possible. -A plethora of research opportunities exist in defining the applications for these consistent/reproducible/well defined lignin “cuts” 39

Strategic Decisions Treating Lignin with respect will pay off Focus & capitalize on current limitations Expand into Hardwood & Biorefinery Lignins Work with Specific Lignin for specific high value applications Work with Industry to bring these to further development

Future Context The perusal of Excellent Science is essential to promote the cause of lignin as a valuable chemical resource; The P&P industry needs to adopt an open mind set & work together with the chemical industry; Our responsibility in creating these relations rests in the accountability of our science & the reliability, resilience & economics of our processes. 41

Acknowledgments Solvay Specialty Polymers Domtar Inc. Plymouth NC King Abdul Aziz University, Centre of Excellence for Advanced Materials Research, Jeddah, Saudi Arabia.

Yields of Fractions Lignin IDSample IDYield (%) Low H Factor Lignin Wood Degraded Less KLN/A AIKL72 ± 3 ASKL-250mLHex3.7 ± 0.3 ASKL-Purified (I)11 ± 1 ASKL-Purified (II)9.5 ± 0.6 High H Factor Lignin Wood Degraded More KLN/A AIKL 32 ± 2 ASKL-250mLHex 31 ± 2 ASKL-Purified (I) 20.8 ± 0.3 ASKL-Purified (II) 15 ± 1

Summative Data on Functional Groups Lignin IDSample IDMnMwPDIAliphatic- OH (g/mol) Non- Condensed Phenolic- OH (g/mol) Condensed Phenolic- OH (g/mol) Total PhOH (g/mol) COOH (g/mol) Low H Factor Lignin KL AIKL ASKL- 250mLHex 2.70± ± ± ± ±0.02 ASKL- 11%* Purified (I) ± ± ± ± ±0.01 ASKL 10%* Purified (II) 1.64± ± ± ± ±0.03 High H Factor Lignin KL AIKL ASKL- 250mLHex ASKL 20%* Purified (I) ± ± ± ± ±0.05 ASKL15%* Purified (II)