brewer characterization presentation nacb2009

8/2/2019 Brewer Characterization Presentation NACB2009

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Catherine Brewer, Rachel Unger, Robert BrownCenter for Sustainable Environmental TechnologiesIowa State University

August 11, 2009


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Biochar Engineering Incubation Study Overview

Meet the Chars General Characterization Results Solid-State 13C NMR Future Work


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Soil Testing:How well does our

char work?

Formulation:What is good

biochar?

Production:How do we make

good biochar?

Characterization:What kind of char

did we make?


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Two Part Study:

Char characterization

8 week soil incubation

Collaboration betweenCSET and Agronomy

17 chars made under

known conditions Results to be used to

select chars for micro-plot field study


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Study ID # Reactor Reaction ConditionsReaction

Temperature (C)

1Fluidized BedPyrolyzer

Fast Pyrolysis 500

2 Free-fall Pyrolyzer Incomplete Fast Pyrolysis 600



5Fluidized BedGasifier

Air-Blown Gasification 732

6 Fixed Bed Pyrolyzer Slow Pyrolysis for 30 min 500


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Study ID # ReactorReaction

ConditionsReaction

Temperature (C)

7 Fluidized Bed Pyrolyzer Fast Pyrolysis 450



10 Fluidized Bed Gasifier60%/40% O2/SteamGasification

824

11 Fluidized Bed Gasifier50%/50% O2/SteamGasification

775

12 Fluidized Bed Gasifier 40%/60% O2/SteamGasification

796

13 Fixed Bed PyrolyzerSlow Pyrolysis for2 hours

500


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Study ID # Feedstock Reactor Reaction Conditions

14

Wood Waste(Chippewa Valley EthanolCompany/Frontline

Bioenergy)

CommercialFluidized BedGasifier

Gasification~800C

15Mixed Hardwood(Struemph CharcoalCompany, Belle, MO)

CommercialCharcoal Kiln

Slow Pyrolysis~400-500C

16 Oak FlourFluidized Bed

Pyrolyzer

Fast Pyrolysis

500C

17Eastern Hemlock(Advanced BioRefinery Inc.,Ottowa, Ontario)

CommercialAugerPyrolyzer

Fast Pyrolysis550C


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0

10

20

30

40

50

60

70

80

90

100

400 500 600 700 800

AshContent(wt%)

Reaction Temperature (C)

Corn Stover Fast PyrolysisCorn Stover Gasification

Corn Stover Slow Pyrolysis

Switchgrass Fast Pyrolysis

Switchgrass Gasification

Switchgrass Slow PyrolysisHardwoods


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0

10

20

30

40

50

60

400 500 600 700 800

BETSurfaceArea(m/g)

Reaction Temperature (C)

Corn Stover Fast PyrolysisCorn Stover Gasification


Switchgrass Fast Pyrolysis

Switchgrass Gasification

Switchgrass Slow PyrolysisHardwoods


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The Techniques:

Qualitative1H-13C Cross Polarization Magic Angle

Spinning (CP/MAS) with TOtal Supression ofSpinning Sidebands (TOSS)

Quantitative 13C Direct Polarization (DP/MAS)

DP/MAS with Dipolar Dephasing, a.k.a. Gated

Decoupling (GADE)

DP/MAS with Recoupled Dipolar Dephasing, a.k.a.Gated Recoupling (GARE)


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Solid-State 13C NMR

Switchgrass Feedstock,

Fast and Slow Pyrolysis

Chars by CP/TOSS at 7 kHz

MAS frequency.

OCH: includes both alcoholand ether moieties


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Solid-State 13C NMR

Corn Stover Fast Pyrolysis

Chars by CP/TOSS at 7 kHz

MAS frequency.

OCH: includes both alcohol

and ether moieties


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Solid-State 13C NMR


Char (right) and Fast

Pyrolysis Char (Below) by

DP and DP/GADE at 14kHz

MAS frequency.

Shows protonated (-) and

non-protonated (-)

fractions.

Note more O-containing

groups in fast pyrolysis

char; more aromatic H inslow pyrolysis char.


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The Final Product:estimates of aromaticring cluster size from Integration of spectral

regions to estimatenumber of edge carbons

Calculation of aromatic

H-C bond distances fromDP/GARE dephasing times

Brewer, C.E.; Schmidt-Rohr, K.; Satrio,J.A.; Brown R.C. Environmental Progress

& Sustainable Energy2009, In Press.


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DP/MAS/GARE Process1. Obtain dephasing time

curves of known

proton-carbon bonddistances

2. Collect DP/MAS/GAREspectra of sampes

3. Compare dephasingtime curves to knownsamples to estimatebond distances

0

0.1

0.2

0.3

0.4

0.5

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0.7

0.8

0.9

1

0 0.5 1 1.5 2

Intensity(S/S0

)

Dephasing Time (ms)

C-C-H

C-C-C-H

Char A

Char B


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Production and characterization of standardchars for use in inter-departmental projects

NMR characterization of switchgrass andcorn stover slow pyrolysis chars producedover a wider range of temperatures (200-800C) and reaction times

Char-alone cation exchange capacitymeasurement methodology


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National Science Foundation GraduateResearch Fellowship (NSF GRF)

CSET colleagues (char samples, CHNS andHHV analysis) Klaus Schmidt-Rohr and Yan-Yan Hu (NMR) Pierce Fleming (CEC) John McClelland and Roger Jones (FTIR-PAS)


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CEC Extractable Colors from Corn Stover FastPyrolysis Chars

Separation Issues

brewer characterization presentation nacb2009

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