Playing with thermodynamics and kinetics:

Efficient conversion of CO2 to chemical energy carriers

Atsushi Urakawa

In New York City, 10 m CO2 spheres emerging at every 0.58 seconds

http://www.carbonvisuals.com

Scale of THE problem

Quantity matters…

After 1 year, 54.3 Mtons of CO2

Only in NY city…

http://www.carbonvisuals.com

Heterogeneous catalysis

4

CO2 hydrogenation

CH4

CH3OH

HCOOH

higher hydrocarbons

CO

CH3OCH3

higheralcohols

H2

H2

H2

CO2 + H2

Natural energy

water electrolysis

FUEL

FUEL FUEL

FUEL

FUEL

H2 CARRIER

C1 FEEDSTOCK

5

CO2 to chemical energy carriers

High-pressure approach

• Hydrogenation to methanol (and DME)

• Hydrogenation to formic acid and methyl formate

• Dimethyl carbonate (DMC) synthesis from CO2 and methanol

Unsteady-state operation

• CO2 capture and conversion in one process for syngas production

+

Conversion

Selectivity

X

S&

6

CO2 to chemical energy carriers

High-pressure approach

• Hydrogenation to methanol (and DME)

• Hydrogenation to formic acid and methyl formate

• Dimethyl carbonate (DMC) synthesis from CO2 and methanol

Unsteady-state operation

• CO2 capture and conversion in one process for syngas production

+

Conversion

Selectivity

X

S&

7

CO2 + 3H2 CH3OH + H2O ΔH298K,5MPa = - 40.9 kJ·mol-1

CO2 + H2 CO + H2O ΔH298K,5MPa = + 49.8 kJ·mol-1

4 2

2 2

Le Châtelier's principle

High pressure & low temperature are favorable for methanol synthesis

RWGS

Methanol synthesis

CO + 2H2 CH3OH ΔH298K,5MPa = - 90.7 kJ·mol-1

3 1

8

180 210 240 270 300 3300

20

40

60

80

100

%

Temperature / OC

330 bar330 bar

182 bar182 bar

30 bar30 bar

180 210 240 270 300 3300

20

40

60

80

100

%

Temperature / OC

CO2 conversion MeOH selectivity

Thermodynamic equilibrium at CO2:H2=1:3

9

High productivity

• Thermodynamics

• Kinetics

Supercritical phase

• High density and high diffusivity

Small reactor size

• For compressive fluids

• Economic

• Enhanced safety

liquid supercritical

Reactor

low P

high P

High-pressure advantages

NOTE: Old methanol synthesis processes were operated

at high-pressure (1920s-1960s, at 250-350 bar) 10

Nanostructured Cu-ZnO (+Al2O3) catalysts

Cu0 ZnO

ZnO

Kasatkin et al., Angew. Chem. Int. Ed., 46, 7324 (2007)

Prepared by co-precipitation method

Active site

Spacer

Highly

active site

11

260 oC, 330 bar, GHSV = 10,471 h-1, Cu/ZnO/Al2O3

95 %

98 %

1:3 1:5 1:7 1:10 1:12 1:140

20

40

60

80

100

SMeOH

XCO2

XC

O2 ,S

Me

OH

/ %

CO2:H

2 / molar ratio

0

10

20

30

40

SCO

SC

O /

%

Effects of feed CO2:H2 ratio

12

30 bar

182 bar

330 bar

30 bar

182 bar

330 bar

Thermodynamic equilibrium

1:3 vs. 1:10 (CO2:H2)

180 210 240 270 300 3300

20

40

60

80

100

%

Temperature / OC

CO2 conversion MeOH selectivity

180 210 240 270 300 3300

20

40

60

80

100

Temperature / OC

%

13

160 180 200 220 240 260 280 300 3200

20

40

60

80

100

SMeOH

XCO2

X C

O2,S

MeO

H /

%

Temperature / C

0

10

20

30

40

50

SC

O /

%

SCO

Kinetic

Regime

Thermodynamic

Regime

CO2:H2 = 1:10, 330 bar, GHSV = 10,471 h-1, Cu/ZnO/Al2O3

Temperature effects

14

Towards full conversion of CO2 to methanol

CO2 + 3H2 CH3OH + H2O

catalyst

catalytic reactorunder high pressure

State-of-the-art Our process

CO2 conversion per pass

Methanol selectivity

Productivity

20-30%

30-60%

1 gMeOH gcat-1 h-1

(excellent case)

>95%

>98%

1-15.3 gMeOH gcat-1 h-1

Editor’s Choice in Science

Bansode & Urakawa, J. Catal. 309, 66 (2014)Granted patents: EP13724223, US9133084, CN104321293

Stoichiometric: Gaikwad, Bansode, Urakawa J. Catal. 343, 127 (2016), EP1638206215

Capillary

Inlet Outlet

Quartz tube

Heater coil

X-ray

• Plug-flow• 300 oC & 330 bar• Fused silica capillary• Facile construction• Tunable length• Space-resolved study• Relevant activity

247 (ID), 662(OD) µm

Fixed-bed

Bansode, Urakawa, et al., Rev. Sci. Instrum. 85, 084105 (2014)

High-pressure operando XAFS

16

▪ CO2:H2 = 1:3

▪ Up to 400 bar, 300 °C

▪ Fused-silica capillary (ID: 150 µm)

Detector

Heater

X-ray

source

Catalyst

High-pressure operando XRD

ZnCO3

15 20 25 30

D= Cu (0)*= ZnO• = ZnCO3

Inte

nsity /

a.u

.

2ϑ / °

••

D

D

•* * * *

200 bar, 300 °C

Reaction time

Gaikwad et al. in preparation 17

Temperature gradients @ 200 bar, CO2:H2 = 1:3

+ operando Raman for C profiling

in out

∆T = +2 °C

CO2 CO CH3OH

endothermic exothermic

Gaikwad, Phongprueksathat et al., Catal. Sci. Technol., 10, 2763 (2020) 18

2CH3OH → CH3OCH3 + H2O ΔH298K = - 23.5 kJ·mol-1

Cu/ZnO/Al2O3 H-ZSM-5

Mixed Bed

Reactor

Direct DME synthesis

19

200 220 240 260 280 3000

20

40

60

80

100

Temperature / C

XC

O2,S

pro

d. /

%

SCO

SMeOH

XCO2

SDME

CO2:H2 = 1:10, P = 360 bar, GHSV = 10471 h-1

Cu/ZnO/Al2O3 + H-ZSM-5 mixed catalyst bed

97 %

89 %

Bansode & Urakawa, J. Catal. 309, 66 (2014)

Direct DME synthesis

20

CO2 to chemical energy carriers

High-pressure approach

• Hydrogenation to methanol (and DME)

• Hydrogenation to formic acid and methyl formate

• Dimethyl carbonate (DMC) synthesis from CO2 and methanol

Unsteady-state operation

• CO2 capture and conversion in one process for syngas production

+

Conversion

Selectivity

X

S&

21

Formic acid

Fuel cellLeather processingFeed preservationChemicals

HCOOH (FA)

22

Formic acid: Promising energy carrier

H2

700 bar

39.4 g L-1

FA

Liquid at RT

53 g L-1

FA → H2 + CO2

TOYOTA

Mirai

HONDA

Clarity

HYUNDAI

Tucson

23

CO2 Hydrogenation to FA

Breakthrough in the 1990s by Noyori’s group • Ru complexes

• In supercritical CO2

• CO2 as reactant and solvent

• Very high activity

CO2 + H2 HCOOH

Jessop, Ikariya, Noyori, Nature, 368, 231 (1994)

Jessop, Ikariya, Noyori, Science, 269, 1065, (1995)

Active transition-metal (Ru & Ir) catalysts since mid 1970s

Jessop

JACS 2002

Baiker

Chem Comm 2007

Nozaki

JACS 2009

Fujita

Nat Chem 2012

Sanford

ACS Catal 2013

Pidko

ACS Catal 2015

24

HCOOH

CH3OH

Reactor 2

catalyst

CO2 + H2

HCOO(H)

CH3OH

HCOOCH3

Reactor 1

Catalyst

Catalyst

Methyl formate (MF)

2-step synthesis

25

Metal effects on MF synthesis

Wu et al., Green. Chem., 17, 1467 (2015)

Filonenko et al., J. Catal., 343, 97 (2016)

Preti et al., Angew. Chem. Int. Ed., 50, 12551 (2011)

Au catalysts for formates synthesis

Au/TiO2

Au/ZrO2

Au/Al2O3

MF

Continuous, 1 wt% M (Cu, Ag, Au)/SiO2, CO2:H2:CH3OH = 4:4:1, 6000 h-1

Ag!

26

In situ DRIFTS & Raman spectroscopy

1 wt% M (Cu, Ag, Au)/SiO2

1800 1700 1600 1500 1400 1300 1200 1100

•

ÿ

ÿ

ÿ

Inte

nsity

Raman shift (cm-1)

•

ÿ

ÿ

3000 2800 2600 1800 1700 1600 1500 1400

0.01

Ag

Au

Ab

so

rba

nce

Wavenumber (cm-1)

Cu

DRIFTS Raman

H2

CO2

formatesformates

1 bar

40 bar

400 bar

200 bar• More formates with pressure

• Strongest signal of formates over Ag/SiO2

1 wt% Cu/SiO2

CO2:H2 = 1:1, 230 oC

27

Transient operando DRIFTS @ 5 bar

3000 2800 2600 1800 1700 1600 1500 1400

0.01

Ag

Au

Ab

so

rba

nce

Wavenumber (cm-1)

Cu

3000 2800 2600 1800 1700 1600 1500 1400

0.01

Ag

Au

Ab

so

rba

nce

Wavenumber (cm-1)

Cu

How many surface species?

What kind of formates?

Tim

e (

s)

Wavenumber (cm-1)

Ar

CO

2+

H2

Ab

so

rba

nce

(milli

ab

s.)

1600

1680

28

Source: interactive audio lab

Multivariate Analysis

Blind → No Reference

Multivariate Curve Resolution

(MCR)

Reducing spectral complexity:Blind source separation (multivariate analysis)

29

Identification of surface species

Time / s1

CO2 + H2

Ar

bi-HCOO (vC-H)

bi-HCOO (vC-O)

Tim

e (

s)

Wavenumber (cm-1)

Ar

CO

2+

H2

Absorb

ance (m

illiabs.)

MCRMultivariate Curve Resolution

2700280029003000

1500160017001800

bi-HCOO (vC-H)

bi-HCOO (vC-O)

?

?

Wavenumber / cm-1

1680 cm-1

1680 cm-1

??2330 cm-1

Three different surface species:

1. 1600 & 2817 cm-1 - bi-HCOO

2. 1680 cm-1 - ?

3. 2330 cm-1 - ??

- 2 & 3 kinetically very similar

- But… different species

- Also observed for SiO2 (weak)

- Less pressure dependent

1

2

3

F

FF

F

?

F

FF

F

?

CO2,ad and…?

F

F

F

30

M M M

? → important for MF formation

MF

MF

M?

F

M?

MFF

CH3OH +

CO2+H2

CH3OH

+ Ar

bi-HCOOad

?(perimeter,1680 cm-1)

Adsorbed MeOH

Transient operando DRIFTS @ 5 bar

31

Reaction mechanism – Ag/SiO2

F

M?

MFF

F

CA

F

CO2

Corral-Pérez et al., J. Am. Chem. Soc., 140, 43, 13884 (2018)

• 1680 cm-1: carbonic acid on SiO2

• 2330 cm-1: adsorbed CO2 on SiO2

M

F

CA

FM

MF

FA

32

Continuous FA/MF synthesis

ChemCatChem, 11, 4725 (2019) J. Catal. 380, 153 (2019)

J. Am. Chem. Soc.,

140, 43, 13884 (2018)

CO2 to chemical energy carriers

High-pressure approach

• Hydrogenation to methanol (and DME)

• Hydrogenation to formic acid and methyl formate

• Dimethyl carbonate (DMC) synthesis from CO2 and methanol

Unsteady-state operation

• CO2 capture and conversion in one process for syngas production

+

Conversion

Selectivity

X

S&

34

Dimethyl carbonate (DMC) synthesis

• Equilibrium limited

• Very low conversions < 1 %

(even at 400 bar!)

• H2O removal is effective

Electrolyte Fuel Additive Non-toxic reagent

O

OO

2 CH3OH H

2OCO

2+ +

35

Tomishige et al., ChemSusChem 1341, 6 (2013)

2-cyanopyridine 2-picolinamide

DMC

Na2O/SiO2

- H2ORegeneration by

94 % DMC yield (12 h) in a batch reactor at 50 bar

State-of-the-art

36

Continuous high-pressure DMC synthesis

MeOH +

2-cyanopyridine

CO2

reactor

BPR

hot-trap

cold-trap

37

Continuous DMC synthesis: Pressure effects

0 50 100 150 200 250 3000

20

40

60

80

100

X

Me

OH ,

SD

MC (

%) S

DMC

XMeOH

Pressure (bar)

>92% (XMeOH)

>99% (SDMC)

Bansode & Urakawa, ACS Catalysis, 4, 3877 (2014)

MeOH : 2-cyanopyridine = 2:1 (10 µL/min), 6 NmL/min (CO2), 120 C, CeO2

Reaction & Residence time

Batch: 12 h

Continuous: 10-100 s

0 20 40 60 80 100

65

70

75

80

85

90

95

Me

OH

co

nve

rsio

n / %

Time / h

But…

30% activity decrease

after 4 days!

38

Operando visualization

Visual inspection (up to 70 bar)

Fresh CeO2

After 24 h

After MeOH

washing

After 300 °C

calcination

Before short washing Praline…

CeO2, 120 °C, 30 bar

Fused silica tube

ID:2 mm, OD: 3mm

No reactivation!

Stoian, Bansode, Medina, Urakawa, Catal Today, 283, 2 (2017)

40

Origin of deactivation

60080010001200140016001800 60080010001200140016001800

Wavenumber / cm-1 Raman Shift / cm-1

IR Raman

After MeOH washing

2-picolinamide

Boiling point of 2-picolineamide: 284 °Cthe source of deactivation

2-picolinamideStoian, Bansode, Medina, Urakawa, Catal Today, 283, 2 (2017)

41

Rare earth metal (REM) doping to CeO2

Less 2-PA adsorption Stoian, Medina, Urakawa. ACS Catal. 8, 4, 3181 (2018)

42

CO2 to chemical energy carriers

High-pressure approach

• Hydrogenation to methanol (and DME)

• Hydrogenation to formic acid and methyl formate

• Dimethyl carbonate (DMC) synthesis from CO2 and methanol

Unsteady-state operation

• CO2 capture and conversion in one process for syngas production

+

Conversion

Selectivity

X

S&

43

Challenge in CO2 conversion: CO2 purity

• Typical CO2 concentration: 3-15%

• Composition: CO2, N2, O2, H2O, …

▪ Most CO2 conversion processes require prior

purification steps

▪ Very expensive: 25-40% increase in energy

requirement for power plants

44

Unsteady-state operation:CO2 capture and reduction (CCR)

syn

ch

ron

iza

tio

n

flue gas CO2

4-way

switching valve

H2

CO2

capture reduction

CO2-free

effluent

CO2 capture

phase

CO2-containing gas

syn

ch

ron

iza

tio

n

flue gas CO2

4-way

switching valve

H2

CO2

capturereduction

Product

stream

CO2 reduction

phase

reducing gas (e.g. H2)

CO2-free effluent Product stream45

0 30 60 90 120 150 180 210

0.0

1.5

3.0

4.5

6.0

CO2

Co

nce

ntr

atio

n /

vo

l.%

Co

ncen

tra

tio

n /

vol.%

Time / s

0.0

0.5

1.0

1.5

2.0

Bobadilla et al., J CO2 Util, 14, 106 (2016)

5.8% CO2 in N2 (27 mL/min) vs. 100% H2 (65 mL/min) at 550 °C (107.5 s each)

CO2 H2

SiC

0 30 60 90 120 150 180 210

0.0

1.5

3.0

4.5

6.0

Co

nce

ntr

atio

n /

vo

l.%

Co

nce

ntr

atio

n /

vol.%

Time / s

0.0

0.5

1.0

1.5

2.0

CH4

CO2

COFeCrCu/K/MgO-Al2O3

CCR catalyst (FeCrCu/K/MgO-Al2O3)for syngas (COx + H2) production

CCR for methanation: Hu & Urakawa, J CO2 Util., 25 323 (2018)

CCR with DAC: Kosaka et al., submitted46

DRIFTS cell: Urakawa et al.,

Angew. Chem. Int. Ed. 47, 9256 (2008)

Space- and time-resolved operando spectroscopy

XRD & XAFSDRIFTS

IR light

gas inlet

gas outlet

ZnSe

window

catalyst

front

back

gas inlet

gas outlet

X-ray

front

back

catalyst

47

Spatiotemporal operando study

130015001700 1300150017001300150017001300150017000

50

100

150

200

FRONT BACK

MS

CO2

CO

Cu-K/Al2O3

350 °C

Tim

e / s

Tim

e / s

Wavenumber / cm-1

Hyakutake et al., J. Mater. Chem. A, 4, 6878 (2016)

5 10 15 20 25 30 35

2θ / °

KOH∙H2O

nano Cu

Protection of Cu

from oxidation

Cu-K/Al2O3

XRD XAS

DRIFTS

Pinto, Work in progress 48

CH4

CH3OH

HCOOH

higher hydrocarbons

CO

CH3OCH3

higheralcohols

H2

H2

H2

MF

DMC+CO2

CO2 + H2

FUEL

FUEL FUEL

FUEL

FUEL

H2 CARRIER

C1 FEEDSTOCK

Take advantages of the thermodynamics & kinetics!!!49

Acknowledgements

Catalysis Engineering @TU Delft, July 2020

Dr. Atul Bansode

Dr. Rohit Gaikwad

Dr. Andrea Álvarez

Nat Phongprueksathat

Donato Pinto

Dr. Dragos Stoian

Dr. Juan José Corral-Pérez

Dr. Luis Bobadilla

Dr. Tsuyoshi Hyakutake

Dr. Lingjun Hu50