and Subsequent Depolymerization Eric L. Hegg Professor, Michigan - - PowerPoint PPT Presentation

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and Subsequent Depolymerization Eric L. Hegg Professor, Michigan - - PowerPoint PPT Presentation

Sep 19, 2022 328 likes •448 views

Strategies for Clean Lignin Streams and Subsequent Depolymerization Eric L. Hegg Professor, Michigan State University Director of MSU Operations, GLBRC MiFBI, October 11-12, 2017 Cu-catalyzed Alkaline Hydrogen Peroxide Pretreatment (Cu-AHP)

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SLIDE 1

Strategies for Clean Lignin Streams and Subsequent Depolymerization

Eric L. Hegg

Professor, Michigan State University Director of MSU Operations, GLBRC

MiFBI, October 11-12, 2017

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SLIDE 2

Cu-catalyzed Alkaline Hydrogen Peroxide Pretreatment (Cu-AHP)

www.glbrc.org

  • Biotechnol. Biofuels 2016, 9, e34

www.glbrc.org

Raw Biomass Extracted Biomass Stage 2

  • 1. NaOH
  • 2. Cu(bpy)
  • 3. H2O2

Stage 1 Alkaline Extraction Cu-AHP Biomass (30 oC) (30 oC) NM6 Hybrid Poplar

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SLIDE 3

Confocal Microscopy Reveals Changes in Lignin Content

Untreated Alkaline Extracted 2-Stage Cu-AHP

In collaboration with Shi-You Ding (MSU)

Cu-AHP pretreatment releases lignin

www.glbrc.org

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SLIDE 4

www.glbrc.org

Lignin: An Underutilized Product

Cu-AHP released 40% or more of the lignin from poplar

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SLIDE 5

www.glbrc.org

Lignin: An Underutilized Product

Cu-AHP released 40% or more of the lignin from poplar

Recovered Lignin

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SLIDE 6

www.glbrc.org

Cu-AHP lignin stream is largely unmodified and maintains the β-O-4 linkages.

Analysis of the Lignin Fraction

Lignin Mn Mw PDI

Cu-AHP (1st stage) 5,800 13,000 2.2 Cu-AHP (2nd stage) 16,800 43,200 2.6 Native lignin 15,100 48,400 3.2

Dioxane Alkali Preextract Cu-AHP

Thioacidolysis Gel Permeation Chromatography

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SLIDE 7

www.glbrc.org

Untreated Hybrid Poplar Cu-AHP Solubilized Lignin

In collaboration with John Ralph and Ali Azarpira (UW-Madison)

Lignin Stream Is Slightly Oxidized

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SLIDE 8

Oxidative Depolymerization

www.glbrc.org

Stahl process: (1) partial oxidation of β-O-4 bonds (2) depolymerization with formic acid

Nature, 2014, 515, 249.

Cu-AHP lignin stream is uniquely susceptible to depolymerization by this process

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SLIDE 9

www.glbrc.org

O O O S R HO HS R OH OH O OH R S S R + R R R R R

  • 1. Use a small molecular thiol to mimic natural pathway
  • 2. Use electrochemistry to reduce disulfide and make

process catalytic

Reductive Depolymerization

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SLIDE 10

www.glbrc.org

thiol Solvent Mole Ratio Temp % Conv. MeCN 1:1 Refluxing 5.86 12.59 18.45 1:2 46.67 52.81 69.10 1:10 25.06 33.75 55.35 1:100 28.66 30.69 34.22 MeCN 1:1 Refluxing 2.17 6.80 8.07 1:2 4.37 9.61 12.24 1:10 17.74 19.12 32.92 1:100 87.89 88.87 99.64

O O R1 R2 HO O R1 R2 thiol, K2CO3, R3 R3

Reductive Depolymerization

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SLIDE 11

www.glbrc.org

Alkaline Delignification Alkaline-Oxidative Post-Treatment Increasing Severity Increasing Severity

Ability to tune pretreatment efficacy and lignin properties

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TEA and LCA will help us simultaneously optimize: Input costs Sugar and lignin yield Lignin properties Subject of a new DOE BETO grant

Improving the Separation of Sugar and Lignin Streams