Hydrothermal Carbonization: A Thermochemical Pathway to Convert Wastes to Conversion-ready Feedstocks

Presenter: Toufiq Reza

Assistant Professor of Chemical Engineering

Biomedical and Chemical Engineering and Sciences

Florida Institute of Technology, Melbourne, FL 32901

BETO Workshop

Advancing the Bioeconomy: From Waste to Conversion-Ready Feedstocks

Arlington, VA

February 19, 2020

Heterogeneity of MSW

2

“Organic waste” is :• food waste• green waste• pruning waste• wood waste• food-soiled paper

waste mixed in with food waste

Organic 48.6%

Inerts and others 11.2%HHW 0.3%

Special Waste1.5%

Mixed Residue2.5%

Paper 19.6%

Glass 2.4%

Metal 4.0%

Electronics0.70% Plastics 9.20%

Associates, E. S. Waste characterization study. Prepared San Francisco Department of the Environment.; 2006.

Example: California

Problems associated with MSW

3Billion ton update: Biomass Supply for a Bioenergy and Bioproducts Industry; OAK RIDGE NATIONAL LABORATORY: 2016

1. Heterogeneous

2. High water content

3. Poor mechanical dewaterability

4. High ash content

5. Low bulk density

6. Low friability

7. Contaminated with organic and inorganic contaminants

Preprocessing of diverse biomass concept proposed by INL

4

Sorting/Metal Recovery

Materials Recovery

5

• More than 300 facilities in the US

• Operated by Waste Management, Republican Services, and Waste connections

• Primarily designed for recycle metals and glass

• Organic fraction of waste is still a liability

Feedstock (unsorted MSW) preparation

6

-20

0

20

40

0 20 40 60 80 100 120

Pre

ss

ure

(p

sig

)

Time (min)

Holtman, K. M. et. al. Waste Management & Research 2015.

Size separated autoclave products

7

Biogenic fractionMSW pulp (<3/8”)

Non-biogenic fraction (1”+)

Comparison of Various Pretreatment Processes

• Energy Input (KWh t-1)

• Autoclave/thermal hydrolysis, grinding/mechanical, and microwave

• Grinding or physical homogenization takes lower energy for further enhancement

• Microwave is the most energy extensive route

Fan, Y.V.et.al. J of Env Manag. 2018, 223, 888-897

9

Anaerobic Digestion

USDA pilot AD system

10

(MSW pulp)< 3/8”

1500 gal high solids anaerobic digester(20 % solids)

Receiving slope

Reaction zoneAttached

growth zone

Weir

back

front

11

VS content increases, NVS content decreases

4689 lb wet pulp• 1630 lb TS• 1214 lb VS

-473 lb cellulose-176 lb hemicelllose-406 lb sCOD-145 lb acid insoluble mat’l (i.e., lignin)

• 416 lb NVS• 3059 lb H2O (367 gal) 817 gal H2O (6814 lbs)

3144 lb wet digestate• 825 lb TS• 520 lb VS

-77 lb cellulose-54 lb hemicellulose- 80 lb dissolved solids- 240 lb lignin- 69 lb est. biomass/others

• 306 lb NVS• 2319 lb H2O (367 gal)

Mass and H2O balance

511 gal H2O (4262 lbs)

87 dry lb TS• 63 lb VS• 24 lb NVS• 2440 lb H2O (293 gal)

157,800 L CH4

12

Anaerobic Digestion

Holtman, K. M. et.al. Bioresource Technology 2015.

13

Hydrothermal Carbonization

Hydrothermal Carbonization

• Hot compressed water (180 – 260 °C)

• Short contact time (< 20 min)

• High Pressure : vapor pressure of liquid water (1-5 MPa)

14

180 – 260 ˚CBiomass

Water

Gases

Hydrochar

HTC process liquid

Biomass

• M. Toufiq Reza, ProQuest, UMI Dissertation Publishing, July 2012. ISBN: 1249074398.• J.G. Lynam, C.J. Coronella, W. Yan, M.T. Reza, V.R. Vasquez ", Bioresource Technology, 2011, 102, 6192-6199. • J. G. Lynam, M. T. Reza, V. R. Vasquez, C. J. Coronella, Fuel 99:271-273 (2012)• J. G. Lynam, M. T. Reza, Wei Yan, and Charles J. Coronella, In preparation for Bioresource Technology.

Advantages of HTC1. Wet process

2. Enhance homogenization

3. Decontaminate wastes

4. Non-catalytic process

5. Straightforward process

6. Hydrophobic hydrochar resulting in ease of filtering

7. Soil amendment, and production of NPK fertilizer

15

Input OutputHTC

Wet biomass Hydrochar

A. A. Peterson, et. al. Energy Environ. Sci., vol. 1, no. 1, 2008, pp. 32–65, 2008.

16

(a) Raw dry MSW digestate

(b) HTC 250 C 30 min MSW digestate hydrochar

(c) HTC 250 C 2 h MSW digestate hydrochar

(d) HTC 300 C 30 min MSW digestate hydrochar

Hydrochars

(a) Raw dry MSW pulp

(b) HTC 250 C 30 min MSW pulp hydrochar

(c) HTC 250 C 2 h MSW pulp hydrochar

(d) HTC 300 C 30 min MSW pulp hydrochar

Van-Krevelen Diagram

17

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2

Ato

mic

H:C

rat

io

Atomic O:C ratio

Anthracite

Biomass

Peat

Lignite

Coal

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0.0 0.2 0.4 0.6 0.8 1.0 1.2

Ato

mic

H:C

rat

io

Atomic O:C ratio

Raw Digestate

Digestate HTC 200-30

Digestate HTC 200-2hr

Digestate HTC 250-30

Digestate HTC 250-2hr

Digestate HTC 300-30

Digestate HTC 300-2hr

Anthracite

Biomass

Peat

Lignite

Coal

Dehydration

Decarboxylation

Demethylation

Reza, M.T. et al. ACS Sus Chem Engr, 2016, 4 (7), 3649-3658

Grindability

Sharma, H.B. et al. Waste Management, Volume 91, Pages 108-119

• Specific case for fibrous biomass

• HTC could improve grindability several times even when biomass is treated at 200 °C

19

-15

-13

-11

-9

-7

-5

-3

-1

1

0

10

20

30

40

50

60

70

80

90

100

0 200 400 600 800 1000

DT

G (

%/m

in)

Mas

s L

oss

(%

)

Temperature (℃)

CW2FW-H230_TG

CW2-H230_TG

FW-H230_TG

Coal_TG

CW2FW-H230_DTG

CW2-H230_DTG

FW-H230_DTG

Coal_DTG

Combustion mass loss curves and DTG curves for untreated and HTC treated samples at 230 ℃

Combustion Characteristics

Reza, M.T. et al. Waste and Biomass Valorization, under-review

Inorganics Leached From Biomass

0

10

20

30

40

50

60

70

80

90

100

Na Ca Mg Al S P Si Fe K Mn

Ino

rga

nic

co

nce

ntr

aio

nin

hy

dro

cha

r(%

)

Raw CS CS 200 CS 230 CS 260

0

10

20

30

40

50

60

70

80

90

100

Na Ca Mg Al S P Si Fe K Mn

Ino

rga

nic

co

nce

ntr

aio

nin

hy

dro

cha

r(%

)

Raw SG SG200 SG230 SG260

Leaching of specific inorganic elements during MHP at different temperatures for corn stover (left) and switch grass (right). Note that inorganic elements present in raw biomass is considered as 100%.

Degradation of Organic Contaminants

Estradiol Oxytetracycline

0

10

20

30

40

50

60

70

80

90

100

180 220 260 280 300 0.5 6.0 3 4 N 8 10 POG

T

t = 0.5 hr, pH = N

t

T = 220 °C,

pH = N

pH

T = 220 °C, t = 0.5 hr

T =

220 °C

t = 0.5

hr

% D

egra

de

t = time (hr), T = Temperature (°C), N = Neutral pH, POG = Presecne of glucose

0

10

20

30

40

50

60

70

80

90

100

180 220 260 280 300 0.5 6.0 3 4 N 8 10 POG

T

t = 0.5 hr, pH = N

t

T = 220 °C,

pH = N

pH

T = 220 °C, t = 0.5 hr

T =

220 °C

t = 0.5

hr

% D

egra

de

t = time (hr), T = Temperature (°C), N = Neutral pH, POG = Presecne of glucose

Saha, N. et al. SN Applied Science, under-review

Dewaterability and Hydrophobicity

Escala, H.B. et al. Energy Fuels, 2013, 27,1, 454-460

Sample Initial drymatter (DM

%)

After Centrifugation (DM%)

After Mechanical

Pressing (DM %)

SewageSludge 1

30 37±0.5

Hydrochar_1_205_7

20 26 52±5.5

SewageSludge 2

10 21 30±1.4

Hydrochar_2_205_7

11 28 70±8.050

60

70

80

90

100

110

120

0.4

0.45

0.5

0.55

0.6

0 1 2 3 4

Co

nta

ct a

ngl

e (d

egre

e)

Wat

er d

rop

let

dia

met

er (

inch

)

Time (min)

HAF (HTC-260)

Engineered pellet: Before

Engineered pellet: After 30 s

Commercial Pellet: Before

Commercial pellet: After 30 s

Mass and Energy Densification

0

5

10

15

20

25

30

35

40

45

1050

1100

1150

1200

1250

1300

1350

1400

Raw HTC 200 HTC 230 HTC 260

ED (

GJ/

m3

)

MD

(kg

/m3

)

MD

ED

MY: Mass Yield EY: Energy Yield MD: Mass Density ED: Energy Density

MD=weight of the pellet

𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑒𝑙𝑙𝑒𝑡

EY= MD of the pellet × HHV of the pellet

DH

Component Density Range (kg/m3)

Typical value(kg/m3)

Food waste 120-480 290

Paper 30-130 85

Glass 160-480 195

Metal 120-1200 320

UncompactMSW

90-180 130

Truck Compact 180-450 300

Well Compact MSW

600-750 600

https://slideplayer.com/slide/10213265/

HTC Process Liquid

24

0

20

40

60

80

100

120

140

0

100

200

300

400

500

600

700

800

900

TN (

mg

/L)

TOC

(m

g/L

)

TOC (mg)

TN(mg)

Carbon Quantum Dots from HTC process liquid

25

A) CQDs under daylight; B) CQDs under UV light

A B

0.35 nm

• Graphene CQDs are $400-600 per liter with ~0.1% concentration (w/v) • Global medical imaging market is $34.1 B in 2017• Catalyst Market Size Expected To Reach $34.3 Billion By 2024• The global optronics market will attain revenues of $5.05bn in 2015

Ongoing Research

NSF-INFEWS

Title: INFEWS/T2: Organic Waste Lifecycles at the Interface of Food, Energy and Water Systems (OWL-FEWs)

Collaborator and Lead: Ohio University

Digestate

DES Gas separator

Biogas

Activation

CO2

Liquid fertilizer

Food production

Char

CO2

AMD

Spent Char

Process liquid

CO2

Clean water

CH4

AMD

MSW

ADHTC

Remediation

Food

Ongoing ResearchUSDA-NIFA-AFRI

Award no: 2019-67019-29288

Title: Development and Optimization of Mild Hydrothermal Preprocessing for High Ash Biomass into Pelletized BiorefineryFeedstocks

Collaborator: INL

Low Ash Fraction

High Ash Fraction

Hydrochar

High Ash Biomass

Inorganic-rich liquid

Pelletized biorefinery feedstock

Air Classification

Mild Hydrothermal Preprocessing

Pelletization

Future Research

EERE/BETO

Title: Decontaminated Pelletized BiorefineryFeedstocks Processing from Non-recyclable Municipal Solid Waste

Collaborator: Universities, National Labs, and Industries

Conclusions

• MSW is heterogeneous, contains high moisture, inorganic and organic contaminants, and have low density

• Sorting/materials recovery/preprocessing will be required to separate recyclables from MSW

• Organic-rich fraction could be benefitted by hydrothermal carbonization as it will• Increase hydrophobicity

• Enhance friability

• Increase density

• Reduce inorganic content on the solid phase

• Decontaminate from emerging organic pollutants

• Future research will require to integrate HTC with other technologies (e.g., AD, air classification, pelletization) to produce a homogeneous and decontaminated feedstock for conversion processes

29

Thank you.treza@fit.edu; website: www.research.fit.edu/reza

Acknowledgements

Award no: 2019-67019-29288

USDA-ARS: Drs. Bill Orts, Diana Franqui

60342-DNI91856058

1 1 0

65 9835

52 50 43

3 2

0

5

10

15

20

25

30

35

40

45

170 190 210 230 250 270 290

Init

ial M

ass

Car

bo

n/M

ass

Ash

Treatment Temperature (°C)

Hydrochar Carbon/Ash Ratio

Positive Effect

Negative Effect

High Carbon andLow Ash

Equal Carbonand Ash

Low Carbon andHigh Ash

Initial Carbon:AshRatio should be greater than 10:1 for treatment to have a positive effect

1 1 0

65 98 35

52 50 43

3 2

0

10

20

30

40

50

60

70

170 190 210 230 250 270 290

Mas

s% C

arb

on

Treatment Temperature (°C)

Hydrochar Carbon/Ash Ratio

Positive Effect

Negative Effect

High Carbon andLow Ash

Equal Carbonand Ash

Low Carbon andHigh Ash

Initial Carbon should be greater than 40 for treatment to have a positive effect

HTC Process Liquid

33

(a) HTC 250 C 30 min

digestate process liquid

(b) HTC 250 C 2 h

digestate process liquid

(c) HTC 300 C 30 min

digestate process liquid

(d) HTC 300 C 2 h

digestate process liquid

(e) HTC 250 C 30 min

pulp process liquid

(f) HTC 250 C 2 h

pulp process liquid

(g) HTC 300 C 30 min

pulp process liquid

(h) HTC 300 C 2 h

pulp process liquid

• Dark in color

• OFMSW derived ones are acidic

• Digestate derived ones are slightly basic

• Have high TOC

• Strong odor

Reza Research Group

Core Research

• Deep Eutectic Solvents (DES)

• Hydrothermal Carbonization (HTC)

Personnel

• Graduate Students: 5

• Undergraduate students: 10

Funding agencies

• USDA-AFRI-Agricultural Wastes

• NSF-INFEWS- Food Waste

• ACS-PRF – Refinery waste

34

Reza Group

Coal

Water

Oil/Gas

Biomass

• Hydrothermal carbonization (HTC)

• CO2 gasification of biochar

• Hydrothermal upgrading of coal waste-biomass

• Carbon quantum dots synthesis from Ohio coal

• SO2-CO2 co-capture by deep eutectic solvents

• Produced water treatment by deep eutectic solvents

• FGD wastewater quality monitoring by ion selective electrodes

• Enhanced shale porosity by hydrothermal degradation

• Adsorption of BTX from aliphatics by deep eutectic solvents