pyrolysis of biosolids to biochar -...

Pyrolysis of Biosolids to Biochar

Dr. Patrick McNamara

Assistant ProfessorDept. of Civil, Construction & Environmental Engineering

Marquette University

Resource Recovery SeminarWednesday, November 14, 2018

Biomass• Wood

• Switchgrass

• Biosolids

Py-gas (5-30%)

Bio-oil (20-50%)

Biochar (~50%)

H2, CO, CH4

Pyrolysis: Heating Without Oxygen

~500°C

Benefits of Biosolids Pyrolysis

Micropollutant Removal

Micropollutant

Adsorption

Nutrient Adsorption

Agricultural Application

Energy Recovery

Enhanced energy

recovery via catalysis

Biosolids

Pyrolysis

Why Pyrolysis for Milwaukee

Metropolitan Sewerage District

(MMSD)?

From MMSD’s 2035 vision

•Meet a net 100% of MMSD's energy needs with renewable energy sources

•Meet 80% of MMSD's energy needs with internal, renewable sources

•Reduce MMSD's carbon footprint by 90% from its 2005 baseline

MMSD Solids Flow Process

Anaerobic Digested

Primary Solids

Drying,

Pelletizing

Soil

Amendment

Land

Application

Waste Activated

Sludge

MMSD Solids Flow Process

Anaerobic Digested

Primary Solids

Drying,

Pelletizing

Soil

Amendment

Land

Application

Waste Activated

Sludge

Pyrolysis

Biochar

Py-Gas (CH4, CO, H2)

Bio-OilEnergy Recovery


Biosolids

Pyrolysis

Energy Recovery

Research Questions

1. What are product yields for pyrolysis of Milorganite?

2. Can this process recover energy for your water resource recovery facility?

Lab-Scale Pyrolysis

Biosolids

(~100 g)

Furnace

Pyrolysis Reactor

(1.6 L)

Gas Sampling Bag

(Py-gas)

Bio-Oil in Ice Bath

(Condensate)

Char and Bio-Oil Yields by Weight

Gas Analysis by GC-TCD

Identify the major (>1%) py-gas products

• Hydrogen [H2]

• Methane [CH4]

• Carbon Monoxide [CO]

• Ethane [C2H4]

• Propane [C3H8]

• Isobutane [C4H10]

• N-butane [C4H10]

• Carbon Dioxide [CO2]

Impact of Temperature on Yields

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

300 400 500 600 700 800 900

Mass Y

ield

Fra

cti

on

Temp (°C)

Char

Py-Oil

Py-Gas

Impact of Temp on Product Yields

McNamara, P.J., Koch, J.D., Liu, Z., Zitomer, D.H., 2016. Pyrolysis of Dried Biosolids Can Be Energy Positive.

Wat. Env. Res. 88 (9), 804-810

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

300 400 500 600 700 800 900

Mass Y

ield

Fra

cti

on

Temp (°C)

Char


McNamara, P.J., Koch, J.D., Liu, Z., Zitomer, D.H.., 2016. Pyrolysis of Dried Biosolids Can Be Energy Positive.

Wat. Env. Res. 88 (9), 804-810

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

300 400 500 600 700 800 900

Mass Y

ield

Fra

cti

on

Temp (°C)

Char

Py-Oil



Wat. Env. Res. 88 (9), 804-810

Bio-Oil

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

300 400 500 600 700 800 900

Mass Y

ield

Fra

cti

on

Temp (°C)

Char

Py-Oil

Py-Gas

↑ Temperature : ↑ Py-gas, ↑ Bio-oil, ↓Char


Wat. Env. Res. 88 (9), 804-810

Bio-Oil

Energy Balance Results:

Pyrolysis Recovers Energy from

Milorganite

Energy in Products (assuming 100% energy recovery) > Energy Required for Pyrolysis

McNamara, P.J., Koch, J.D., Liu, Z., Zitomer, D.H., 2016. Pyrolysis of Dried Biosolids Can Be Energy Positive.

Wat. Env. Res. 88 (9), 804-810

Pyrolyzing dewatered biosolids at 95% solids

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

Energy Required Energy Content

kJ/k

g-b

iosolid

s

Pyrolysis Drying Py-gas Bio-Oil

What if you have wet biosolids?

Drying is Energy IntensiveDewatered Biosolids at 20% Solids


Wat. Env. Res. 88 (9), 804-810

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000


kJ/k

g-b

iosolid

s


Energy in Products (assuming 70% energy recovery) < Energy Required for Pyrolysis & Drying


Wat. Env. Res. 88 (9), 804-810

Pyrolyzing dewatered biosolids at 20% solids

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000


kJ/k

g-b

iosolid

s


Pyrolysis could be used to offset some drying energy costs


Biosolids

Pyrolysis

Energy Recovery


Enhanced energy


Biosolids

Pyrolysis

Energy Recovery

Bio-oil is difficult to handle

Properties of bio-oil:

1. Acidic

2. High oxygen content

3. Corrosive

4. Thermally unstable

Oil is corrosive & py-gas more readily used…

Can we convert bio-oil to py-gas?

?

Lab-scale Catalytic Pyrolysis SystemCatalytic Tubular Reactor

Pyrolysis Reactor

1. Reactor vessel

2. Radiative heater

3. Gas purge, release

and vacuum system

4. Thermocouple and

pressure gauge

5. Tubular reactor

6. Radiative heater

7. Condensers

8. Chiller and ice bath

9. Connector for Tedlar®

bag

10. PID controller

11. Flowmeter

12. Gas tank

Mobile Lab-scale

Pyrolysis System

Metals in biochar will provide catalytic activity to crack bio-oil into py-gas

Hypothesis

•Determine the catalytic impact on the product yield distribution

(i.e. mass fraction)

•Determine the catalytic impact on the product properties

(e.g. composition, optical property)

•Determine the catalytic impact on the product energy distribution

Research Objectives

No Major Catalytic Impacts at 500 or 600ºC

Liu, Z., McNamara, P., Zitomer, D. 2017. Autocatalytic pyrolysis of wastewater biosolids for product upgrading. Environmental

Science & Technology, 51 (17), 9808–9816.

Major Catalytic Impacts at 700 and 800ºC



Py-Gas Increased, Bio-oil Decreases:

Does Bio-oil quality improve?

Optical Property Change of Bio-oil Product



Catalyst

No Catalyst

Product energy distribution per mass of biosolids pyrolyzed

Product energy = Yield × Higher Heating ValueLiu, Z., McNamara, P., Zitomer, D. 2017. Autocatalytic pyrolysis of wastewater biosolids for product upgrading. Environmental


What is the mechanism for biosolids as a catalyst?

Prominent Metal Content in Biosolids

0

2

4

6

8

10

12

Ca Fe Mg P

Meta

l C

onte

nt

(% D

ry W

eig

ht)

Biosolids

Grains

Calcium and Iron Improve Catalysis



What about other biomass sources for catalysts?

How do wastewater biosolids compare?

A: Corn stover

B: Dried distillers grains

with solubles

F: Pinewood residue

L: Cow manure

P: Paper mill sludge

W: Wastewater biosolids

Most of these industrial

wastes have annual

production of millions

dry tons in the United

States

Industrial Waste Candidates for Biochar Catalyst Precursors

Product Distribution

0Q: Control test

A: Corn stover

B: Dried distillers grains with solubles

F: Pinewood residue

L: Cow manure



0Q: Control test

A: Corn stover

B: Dried distillers grains

with solubles

F: Pinewood residue

L: Cow manure



Optical Property Change of Bio-oil Products (800℃)

0Q: Control test A: Corn stover

B: Dried distillers grains with solubles F: Pinewood residue

L: Cow manure P: Paper mill sludge W: Wastewater biosolids

How does this process scale up?

Bench Scale, Sub-Pilot Scale, Pilot Scale

0.1 kg (per batch test)


0.5 kg/hr

Sub-Pilot > Bench

Liu, Z., Singer, S., Zitomer, D., McNamara, P. 2018. Sub-pilot-scale autocatalytic pyrolysis of wastewater biosolids for enhanced

energy recovery. Catalysts, 8 (11), pp. 11.


68 kg/hr

Catalysis works in pilot-scale too


Enhanced energy


Biosolids

Pyrolysis

Energy Recovery


Nutrient Adsorption

Enhanced energy


Biosolids

Pyrolysis

Energy Recovery


Nutrient Adsorption


Enhanced energy


Biosolids

Pyrolysis

Energy Recovery

Biochar as a Beneficial Soil Amendment

• Improved moisture holding capacity

•Carbon sequestration

•Adsorb ammonia from belt filter press filtrate

$13 a jar


Carey D.E., McNamara, P.J., Zitomer, D.H. 2015. Biochar from Pyrolysis of Biosolids for Nutrient

Adsorption and Turfgrass Cultivation. Wat. Env. Res. 87 (12), 2098-2105.


Nutrient Adsorption

Enhanced energy


Biosolids

Pyrolysis

Energy Recovery


Nutrient Adsorption


Enhanced energy


Biosolids

Pyrolysis

Energy Recovery


Micropollutant Removal Nutrient Adsorption


Enhanced energy


Biosolids

Pyrolysis

Energy Recovery

Pyrolysis removes micropollutants from biosolids

BD: Below Detection Limit


Ross J.J., Zitomer, D.H., Miller, T.R., Weirich, C.A., McNamara, P.J. 2016. Emerging investigators series: pyrolysis

removes common microconstituents triclocarban, triclosan, and nonylphenol from biosolids. Environ. Sci.: Water

Res. Technol (2) 282-289.

BD: Below Detection Limit


Hoffman TC., Zitomer, D.J. McNamara, P.J. 2016. Pyrolysis of wastewater biosolids significantly reduces

estrogenicity. J. Haz. Mat. 317, 579-584

Ross J.J., Zitomer, D.H., Miller, T.R., Weirich, C.A., McNamara, P.J. 2016. Emerging investigators series: pyrolysis

removes common microconstituents triclocarban, triclosan, and nonylphenol from biosolids. Environ. Sci.: Water

Res. Technol (2) 282-289.


Kimbell, L., Kappell, A., McNamara, P. 2018. Effect of pyrolysis on the removal of antibiotic

resistance genes and class 1 integrons from municipal biosolids. Environmental Science: Water

Research & Technology, 4, 1807-1818.

Stripes indicate below detection limit


Micropollutant Removal Nutrient Adsorption


Enhanced energy


Biosolids

Pyrolysis

Energy Recovery



Micropollutant

Adsorption

Nutrient Adsorption


Enhanced energy


Biosolids

Pyrolysis

Energy Recovery

Removal of Micropollutants from Wastewater Using Biochar as an Adsorbent

Removal of Micropollutants from Wastewater Using Biochar as an Adsorbent

Tong YT, Mayer, BK., McNamara, PJ. 2016. Triclosan adsorption using wastewater biosolids-derived biochar.

Environ. Sci.: Water Res. Technol 2 (4), 761-768



Micropollutant

Adsorption

Nutrient Adsorption


Enhanced energy


Biosolids

Pyrolysis

Energy Recovery

Big Picture

Conventional Solids Treatment System

NEWAGE System

(Nutrient, Energy, Water for Agriculture and Green Environment)

Marquette pilot-scale

pyrolysis system

Interested in Collaborations?

Patrick McNamara, PhD

Assistant Professor

Civil, Construction & Environmental

Engineering

Marquette University | P.O. Box 1881

Milwaukee, Wisconsin 53201-1881

Phone: 414-288-2188

[email protected]

mailto:[email protected]

Acknowledgements

Faculty

Dr. Daniel Zitomer

Dr. Zhongzhe Liu

Dr. Simcha Singer

Dr. Jon Koch

Collaborators

Mr. Matt Magruder(Milwaukee Metropolitan Sewerage District)

Mike Dollopf & other WQC

colleagues

Graduate Students

John Ross

Thomas Hoffman

Yiran Tong

Erik Anderson

Daniel Carey

Lee Kimbell

Undergraduate Students

John Kissel

Mark Wendtland

Hui Liu

Matthew Hughes

Questions?

0%

20%

40%

60%

80%

100%

Triclosan Triclocarban Nonylphenol Estradiol

Recovery

Sand

Tubing

Impingers

Greater Triclosan and Nonylphenol Recovery

Triclocarban Products

Dechlorinated Triclocarban Found

Standard

Impinger


Standard

Impinger

Ross et al., 2016. Emerging investigators series: pyrolysis removes common microconstituents triclocarban,

triclosan, and nonylphenol from biosolids. Environ. Sci.: Water Res. Technol (2) 282-289.


Standard

Impinger

Pyrolysis can transform micropollutants

Ross et al., 2016. Emerging investigators series: pyrolysis removes common microconstituents triclocarban,

triclosan, and nonylphenol from biosolids. Environ. Sci.: Water Res. Technol (2) 282-289.

Impact of Temperature on Gas Composition and Energy Content

↑ Temperature : ↑ HHV

y = 33.418x - 7815.2R² = 0.8145

0

2,000

4,000

6,000

8,000

10,000

0

5,000

10,000

15,000

20,000

25,000

300 400 500 600 700 800 900

BT

U/l

b g

as

HH

V (

KJ

/kg

-gas)

Temperature (°C)

Biogas

Impact of T on Gas Energy Content

Energy Costs of Pyrolysis

Energy

In

800°C 40C/min ramp

Energy lost during pyrolysis

(sensible, latent heat loss)

Energy Cost

(Heat of

Pyrolysis)

Energy

Out Py-Oil, HV

Py-Gas, HV

Heat of Pyrolysis

Energy

In

Energy

Out

10C/min ramp 40C/min ramp

Heat of Pyrolysis

Energy

In

Energy

Out

Energy

Cost

Surface Area and Ultimate Analysis

Milorganite Biochar ActivatedBiochar

Zeolite Peat

Surface Area (m2/g)

- 10 19 15 -

C (%) 36.0 31.6 30.5 - 44.4

H (%) 5.6 2.1 2.7 - 5.9

N (%) 6.3 5.2 4.9 - 0.9

S (%) 0.8 0.9 0.7 - 0.1

SolubleSample Salts NH4-N NO3-N Total C Total N

ID pH dS/m (ppm) (ppm) (%) (%) C/N

1. Millorginite 6.3 3.2 590 2.1 34 7.0 5

2. Millorginite Biochar 6.8 0.47 33 0.78 32 6.4 5

3. Millorginite Activated Biochar 8.0 0.92 13 0.70 33 6.4 5

5. Peat 5.3 0.06 11 19 44 0.8 55

Sample P K Ca Mg Fe NaID ppm ppm ppm ppm ppm ppm

1. Milorganite 200 800 470 240 52 4002. Milorganite Biochar 6.1 640 460 22 37 160

3. Milorganite Activated Biochar 8.9 600 34 27 5.3 9705. Peat 1.6 3.5 46 19 16 10.00

Nutrient Value

pyrolysis of biosolids to biochar -...

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