Matching Biochar Characteristics with Metals- C Contaminated Soil - - PowerPoint PPT Presentation

Matching Biochar Characteristics with Metals- C i d S il Eff i l R d M l Contaminated Soil to Effectively Reduce Metal Bioavailability at Mining Sites

Mark G. Johnson

Research Soil Scientist Research Soil Scientist

Clu-In Seminar November 7, 2017

Outline of Presentation

• What is biochar?
• How is biochar made?
• Biochar properties

Biochar properties

• Biochar and metal sorption
• Why EPA and biochar?

Bi h d t f t l

• Biochar as an amendment for metal

contaminated spoil soils

• Tuning biochar properties to address spoil soil

limitations limitations

• Insuring a good match between site conditions

and soil amendments

• Field Studies

Field Studies

• Target soils
• Monitoring site conditions
• Summary

Summary

• Outlook for the future

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What is Biochar?

• Carbon-rich solid produced

by heating biomass in the by heating biomass in the absence of oxygen (pyrolysis)

• Residual product of bio-

p energy production

• Porous solid with a number

Biochar from Wood Chips

• f beneficial properties
• Properties depend upon

f d k l feedstock, pyrolysis conditions and possibly other modifications modifications

Biochar from Wood Pellets

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What is Biochar?

Ponderosa Pine Biochar Poultry Litter Biochar

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Ponderosa Pine Biochar Poultry Litter Biochar

Charcoal being added to Willamette Valley soil following a grass field fire

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Making Biochar via Pyrolysis: Energy Extraction from Biomass Energy Extraction from Biomass

Concept diagram of low-temperature (350 to 500 °C) pyrolysis based bio-energy production with biochar storage in soil. Typically, between 20 and 50% of the initial biomass carbon is converted into biochar and can be returned to soil (Lehmann, 2007).

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Comparison of Pyrolysis Processes for Syngas (Energy) and Biochar Production (Energy) and Biochar Production

http://www.csiro.au/files/files/poei.pdf

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Pyrolyzers: Heating Biomass Without Oxygen

Old School Highly Controlled Lab-Scale Industrial Portable

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Slide - D. Crowley

Modern Slow Pyrolysis Unit: Prineville, OR

Beehive, Teepee or Wigwam Burner – Historically used to burn sawmill wastes

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Feedstock Hopper Pyrolysis Retort Biochar Product

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Examples of Biochar Feedstocks

Pine Chips Switchgrass Pine Chips Switchgrass Swine Solids Poultry Litter Swine Solids Poultry Litter

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Energy Extraction and Biochar Production

Wood Chip

Saw Mill Waste Coarse Wood Chips Wood Chips Feed Into Gasification Retort

Wood Chip Auger Retort Fine Bi h Coarse Biochar Retort Volatile Gases Boiler Biochar

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Volatile Gases From Retort Feed Into Boiler Hot Water From Boiler Heats 5 Acres of Greenhouses “Waste Product” = High Quality Biochar

Biochar has a Range of Structural Properties that Depend Upon Pyrolysis Temperature and Conditions Depend Upon Pyrolysis Temperature and Conditions

(Keiluweit et al, 2010)

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Adsorption, Leaching, and Distribution of Simazine in Soils Amended with Biochar

Control Control

D.L. Jones et al. / Soil Biology & Biochemistry 43 (2011) 804-813

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Weed control of barnyard grass with Diuron herbicide applied at different concentrations to soil amended with varying y g concentrations of wheat straw biochar. (Yang 2006)

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Key Biochar Properties Key Biochar Properties

• pH
• Ash content
• Ash content
• Proximate carbon
• Volatile matter

i d b

• Fixed carbon
• Surface area
• Porosity

Porosity

• Pore size distribution
• Chemistry
• Total elemental
• Total elemental
• Nutrients
• Cation exchange capacity (CEC)

17

SEM Images of Douglas-fir Wood Chip Feedstock and Biochar

300 °C Raw Feedstock 400 °C 500 °C 600 °C 700 °C

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Proximate Carbon Analysis

• Quantify three constituents
• f biochar

l il

Procedure

Adapted from ASTM Method D1762-84: Chemical Analysis of Wood Charcoal

• Volatile matter
• Low molecular weight carbon
• Labile carbon fraction

Fi d b

Weigh Dry Biochar into Inconel Crucibles (A) Heat Biochar in Covered

• Fixed carbon
• Stable forms of carbon
• Biopolymer (lignin, cellulose,

hemicellulose etc )

Crucibles at 950°C for 6 minutes. Reweigh when cool. (B)

hemicellulose, etc.)

• High degree of aromaticity
• Ash content
• Residual mineral matter

Heat Biochar in Uncovered Crucibles at 750°C for 6 hours.

• Residual mineral matter

Reweigh when cool. (C)

Volatile matter = B – A; Fixed carbon = B – C; Ash content = C

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Ternary Plot of Proximate Carbon Fractions Formosa Mine Extract Study - Summer 2014

Arundo donax - 300 C° Arundo donax - 500 C° Arundo donax - 700 C° Anaerobically Digested Fiber - 300 C° Anaerobically Digested Fiber - 500 C°

†

90 100 10 Anaerobically Digested Fiber 500 C Anaerobically Digested Fiber - 700 C° ARS Char #1 ARS Char #2 ARS Char #3 ARS Char #4 ARS Char #5

% A s h

70 80 90

r b

• n

20 30 40 ARS Char #5 ARS Kentucky Bluegrass Seed Screenings ARS Rice Seed Screenings ARS Tall Fescue Seed Screenings ARS Wood Douglas fir - 300 C°

s h C

• n

t e n t

40 50 60

% F i x e d C a r

40 50 60 Douglas fir - 500 C° Douglas fir - 700 C° Dairy Manure Biochar (Enchar) Elymus - 300 C° Elymus - 500 C° Elymus - 700 C° 10 20 30 70 80 90 y Granulated Activated Charcoal Hazelnut Shells - 300 C° Hazelnut Shells - 500 C° Hazelnut Shells - 700 C° Miscanthus - 300 C° Miscanthus 500 C°

300 °C 700 °C

% Volatile Matter

10 20 30 40 50 60 70 80 90 100 10 100 Miscanthus - 500 C Miscanthus - 700 C° Oregon White Oak - 300 C° Oregon White Oak - 500 C° Oregon White Oak - 700 C° Spent Brewer's Grain - 300 C°

500 °C

Spent Brewer's Grain - 500 C° Spent Brewer's Grain - 700 C° Sorghum - 300 C° Sorghum - 500 C° Sorghum - 700 C°

†ASTM Method D-1762

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Physical Properties of Biochar from y p Different Feedstocks: Grass Grass† vs. Wood Wood‡

Pyrolysis Temperature (°C)

Yield

(wt%)

Yield

(wt%) Carbon Content (wt%)

Carbon Content

(wt%)

Volatile Matter

(wt%)

Volatile Matter

(wt%)

Fixed Carbon

(wt%)

Fixed Carbon

(wt%)

Ash*

(wt%)

Ash*

(wt%)

Surface Area

(m2g-1)

Surface Area

(m2g-1)

100 99.9 99.8 48.6 50.6 69.6 77.1 23.5 21.7 6.9 1.2 1.8 1.6 200 96.9 95.9 47.2 50.9 70.7 77.1 23.6 21.4 5.7 1.5 3.3 2.3 300 75.8 62.2 59.7 54.8 54.4 70.3 36.2 28.2 9.4 1.5 4.5 3.0 400 37.2 35.3 77.3 74.1 26.8 36.4 56.9 62.2 16.3 1.4 8.7 28.7 500 31.4 28.4 82.2 81.9 20.3 25.2 64.3 72.7 15.4 2.1 50 196 600 29.8 23.9 89.0 89.0 13.5 11.1 67.6 85.2 18.9 3.7 75 392 700 28 8 22 0 94 2 92 3 9 1 6 3 71 6 92 0 19 3 1 7 139 347 700 28.8 22.0 94.2 92.3 9.1 6.3 71.6 92.0 19.3 1.7 139 347

†Tall Fescue,

Tall Fescue, ‡Ponderosa pine Ponderosa pine

*Ash = Metal and non-metal oxides, chlorides, phosphates, and carbonate residue (From Keiluweit et al, 2010)

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Physical Properties and pH of Douglas-fir Biochar: A Function of Pyrolysis Conditions and Feedstock

Property 300 °C 400 °C 500 °C 600 °C 700 °C

A Function of Pyrolysis Conditions and Feedstock

Production Yield (%)

49.9 36.6 31.3 28.8 27.2

Volatile Matter Volatile Matter (%)

46.90 32.35 20.54 11.80 7.96

Fixed C (%)

52.70 67.16 78.87 87.51 89.12

Ash Content (%)

0.40 0.48 0.59 0.69 2.93

Surface Area

3 7 13 7 353 6 391 3 379 9

(m2g-1)

3.7 13.7 353.6 391.3 379.9

pH

4.67 5.95 6.68 7.48 8.22

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Fourier Transformed Infrared (FTIR) Spectra of Douglas fir Biochar and Feedstock Fourier Transformed Infrared (FTIR) Spectra of Douglas-fir Biochar and Feedstock

O-H Aliphatic C-Hs 700°C C=O C=C C-O

bance

600°C 500°C Aromatic C-Hs C=C C-O C-O from Polysaccharides

lative Absorb

400°C

Rel

300°C Feedstock

Wavenumbers (cm-1)

400 600 800 1200 1400 1600 1800 2200 2400 2600 2800 3200 3400 3600 3800 1000 2000 3000 4000 Transmission FTIR: 0.5 % material in pressed KBr pellet

Wavenumbers (cm )

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Early Research: First Study

Mine spoil “soil” from Leadville, CO

Si l d i (S ) i

• Simulated Rainwater (SRW) extraction

(pH 4.5)

• 25 mls of filtered SRW added to 0.25 g
• f Douglas-fir biochar
• 24 hour contact time
• Biochar separated from SRW solution

Biochar separated from SRW solution

• Characterization of SRW solution with

ICP AES ICP-AES

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% Change in Initial Metal Concentration of Simulated Rainwater Extract of Leadville CO Mine Spoil after 24 Hour Contact with

Initial Metal

Extract of Leadville, CO Mine Spoil after 24 Hour Contact with Douglas-fir Biochar

Metal

Concentration (mg kg-1 biochar)

300 °C 400°C 500°C 600°C 700°C Al 247 3.8 21.8 68.2 92.9 98.6 Ca 57922

• 0.4
• 0.8
• 1.0
• 2.4
• 2.6

Cd 101 3.7 3.9 5.0 5.3 6.4 Cu 204 8.4 17.5 65.1 87.1 97.4 Mg 8441 3.8 3.4 2.8 2.1 5.9 Mn 2364 4 5 4 2 3 7 3 2 7 4 Mn 2364 4.5 4.2 3.7 3.2 7.4 Pb 198 11.2 21.1 54.8 72.5 95.3 Zn 8720 3.6 2.9 3.1 3.6 5.5

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Early Research: Second Study

Cu sorption on biochar

• 25 mls of a 5 mM Cu(NO3)2·2.5 H2O

solution added to 0.25 g of Douglas- fir biochar

• 24 hour contact time
• Biochar separated from Cu solution,

washed with MeQ water and dried Q

• Cu sorption characterized with X-Ray

Absorption Spectroscopy Absorption Spectroscopy

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Micro X-ray Absorption Spectroscopy (µXAS): ALS Beamline 10.3.2

Samples Mounted with Kapton tape Kapton tape X-ray Beam Sample Support 5 mm X-ray beam spot size: 3 – 10 µm

27

Biochar Fluorescence Chemistry Maps

300 °C Douglas-fir Biochar treated with 5mM Cu C C K

200µm

CuCaK

200µm

500 °C Douglas-fir Biochar treated

200µm

with 5mM Cu CuCaK 700 °C

200µm

Douglas-fir Biochar treated with 5mM Cu CuCaK

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X-ray Absorption Fine Structure (XAFS) X ray Absorption Fine Structure (XAFS)

• f Cu on Douglas-fir Biochar

1.4 1.6

XANES

µ(E)

1.0 1.2

EXAFS

sorbance - µ

0.6 0.8

XANES = X-ray Absorption Near Edge Structure

Abs

0.2 0.4

300 °C - Spot 2 500 °C - Spot 1

EXAFS = Extended X-ray Absorption Fine Structure

E ( V)

9000 9200 9400 9600

• 0.2

0.0

p 700 °C - Spot 2

Cu K-edge = 8979 eV

Energy (eV)

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XANES of Cu(II) Standards

ance - µ(E) zed Absorba Normaliz

Cu Acetylacetonate Cu(II) on Graphite

Cu on DF Feedstock

Cu Acetate Cu Hydroxide Cu Carbonate Cu Oxide - 1 Cu Oxide - 2 y

Energy (eV)

8950 9000 9050 9100 9150 30

X-ray Absorption Near Edge Structure (XANES) X ray Absorption Near Edge Structure (XANES)

• f Cu on Douglas-fir Biochar

1.4 1.6

µ(E)

1.0 1.2

Peak &

sorbance - µ

0.6 0.8

Pre-edge Peak & Post-edge

Ab

0.2 0.4

300 °C - Spot 2 500 °C - Spot 1

g

E ( V)

8950 9000 9050 9100 9150

• 0.2

0.0

p 700 °C - Spot 2

Cu K-edge = 8979 eV

Energy (eV)

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XANES f C 300 °C D l fi Bi h d C St d d XANES of Cu on 300 °C Douglas-fir Biochar and Cu Standards

1.2 1.4

• µ(E)

0.8 1.0

bsorbance -

0.4 0.6

Ab

0.0 0.2

300 °C - Spot 2 Cu Acetate Cu(II) on DF Feedstock

Energy (eV)

8950 9000 9050 9100 9150

• 0.2

Cu Acetylacetonate

Energy (eV)

32

XANES of Cu on 500 and 700 °C Douglas-fir XANES of Cu on 500 and 700 C Douglas fir Biochar and Graphite

1.4 1.6

µ(E)

1.0 1.2

sorbance - µ

0.6 0.8

Abs

0.2 0.4

500 °C - Spot 1

E ( V)

8950 9000 9050 9100 9150

• 0.2

0.0

Cu(II) on Graphite p 700 °C - Spot 2

Energy (eV)

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Observations and Conclusions from Early Studies

• Biochar from Douglas-fir (DF) has the potential for remediating

metal contaminated soils and waters for certain metals

• For some metals sorption is a function of the pyrolysis

temperature

• Pyrolysis temperature↑ metal sorpon↑
• Metal sorption in low temperature (≤ 400 °C) DF biochar

appears to be controlled by oxygen-containing functional groups and appears to be relatively weak association for Cu(II)

• In contrast, metal sorption in higher temperature (> 400 °C) DF

biochars does not appear to be controlled by oxygen-containing functional groups g p

• Possible explanations for sorption in the high temperature

biochar include physisorption of metals in micropores and/or pi-bonding with aromatic p systems that form during pyrolysis. pi bonding with aromatic p systems that form during pyrolysis. The mechanism for this sorption still needs to be resolved.

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