Electrochemical synthetic hydrocarbons - Rambach - for printing with title page

Electrochemistry and Synthetic Hydrocarbons

from Water and Carbon Dioxide Glenn Rambach

Third Orbit Power Systems, Inc.

Sept. 2009

Basics

High-temperature solid oxide electrochemistry for:

1) Fuel cells

2) Electrolysis


from Water and Carbon Dioxide


from Water and Carbon Dioxide

Water + CO2 to Fuels Like Diesel Fuel

O2 + 4e_ 2O2

_

Porous

metal/ceramic cathode Dense, Solid

Electrolyte

(usually yttrium stabilized zirconia, YSZ)

Porous

metal/ceramic anode

H2O and/or

CO2

H2 and/or CO

e-

External

Load

O2

Basic solid oxide fuel cell (SOFC) mechanism

and/or

Fuel

side Air

side

Temperature:

600 - 1000C

H2 + O2_ H2O + 2e

_

CO + O2_ CO2 + 2e

_

O2_

O2_

O2_

O2_

All reactions are

reversible to permit

water and CO2

electrolysis from an

applied voltage.

e-

Applied voltage

2O2_

O2 + 4e_

Porous

metal/ceramic cathode Dense, Solid

Electrolyte

(usually yttrium stabilized zirconia, YSZ)

Porous

metal/ceramic anode

H2O and/or

CO2

H2 and/or CO

O2

Basic solid oxide electrolysis cell (SOEC) mechanism

and/or

Fuel

side Oxygen

side

Temperature:

600 - 1000C

H2O + 2e_

H2 + O2_

CO2 + 2e_ CO + O2

_

O2_

O2_

O2_

O2_

How do the reactants and products transport?

Where do reactions take place?

Electrochemical removal of oxygen and selective catalyst choices can favor

efficient use of electrolyzed hydrogen in production of synthetic fuel.

Electrochemically selective removal of half the oxygen from CO2 reduces the

consumption of hydrogen by 33%, compared to the use of reverse water gas

shift reaction, in the production of synthetic hydrocarbon fuel.

Porous cathode

Dense electrolyte

Porous anode Thermo-catalyst/Electro-catalyst

Gaseous flow channel

Electrolysis

electrode-electrolyte assembly



Gaseous flow

e-

O2_

O2_ O2

_ O2

_

O2_

O2_ O2

_ O2

_

e_

e_

e_

e_

e_

e_ e

_

e_

CO2

H2O CO

CO2 + 2e_ CO + O2-

H2O + 2e_ H2 + O2-

H2

2O2- O2 + 4e_ O2

H2

CO

To conventional

Fisher-Tropsch

liquid fuel production

2H2 + CO CH2 + H2O

Lost hydrogen

Electrochemically removed oxygen



Electrochemically selective removal of all oxygen from CO2 reduces the

consumption of hydrogen by 66%, compared to the use of reverse water gas

shift reaction and Fisher-Tropsch reaction 1, in the production of synfuel.


efficient use of electrolyzed hydrogen in production of synthetic fuel. Electrochemical removal of oxygen and selective catalyst choices can favor


e-

O2_

O2_ O2

_ O2

_

O2_

O2_ O2

_ O2

_

e_

e_

e_

e_

e_

e_ e

_

e_

CO2

H2O

CO2 + 2e_ CO + O2-

CO* + ½H2 + 2e_ CH + O2-

CH + ½H2 –CH2–

H2O + 2e_ H2 + O2-

2O2- O2 + 4e_ O2

[CH2]n

No lost

hydrogen

Electrochemically removed oxygen



CO H2

e-

O2_

O2_ O2

_ O2

_

O2_

O2_ O2

_ O2

_

e_

e_

e_

e_

e_

e_ e

_

e_

These and similar reactions may take place far

downstream, at lower temperature and with different catalyst.

CO2

H2O

CO2 + 2e_ CO + O2-

CO* + ½H2 + 2e_ CH + O2-

CH + ½H2 –CH2–

H2O + 2e_ H2 + O2-

2O2- O2 + 4e_ O2

[CH2]n

No lost

hydrogen



CO H2

How do the flow channels, electrochemical

surface and down stream catalysts look in

a typical configuration?

Synfuel from CO2 and H2O using electrochemistry


Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

e- H2O

and

CO2


Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

e- H2O

and

CO2

Catalyst


Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

e- H2O

and

CO2

H2O CO2

Catalyst


Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

e- H2O

and

CO2

H2O CO2

Catalyst

O2_

O2_

O2_

O2_

O2_

O2


Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

e- H2O

and

CO2

H2O CO2

Catalyst

O2_

O2_

O2_

O2_

O2_

2O2_

O2 + 2e_

O2


Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

e- H2O

and

CO2

H2O CO2

Catalyst

CO

O2_

O2_

O2_

O2_

O2_

H2

2O2_

O2 + 2e_

O2

CnH2n+2

(Synfuel)


Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

O2_

O2_

O2_

O2_

O2_

e- H2O

and

CO2

H2O CO2

Catalyst

2O2_

O2 + 2e_

H2

CO


O2

CnH2n+2

(Synfuel)

Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

O2_

O2_

O2_

O2_

O2_

e- H2O

and

CO2

H2O CO2

Catalyst

2O2_

O2 + 2e_

H2

CO

Triple

Region

H

O=

e-

e- O

H H

Electrocatalyst

Cathode

H O=


CnH2n+2

(Synfuel)

Catalyst

O2

CnH2n+2

(Synfuel)

Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

O2_

O2_

O2_

O2_

O2_

e- H2O

and

CO2

H2O CO2

Catalyst

2O2_

O2 + 2e_

H2

CO

n[CO2 + 2e_

CO + O2_ ]

n[H2O + 2e_

H2 + O2_ ]

Triple

Region

H

O=

e-

e- O

H H

Electrocatalyst

Cathode

H O=


Temperature: 600 - 1000C

(Riso uses 650C for

2H2O + CO2 CH4 + 2O2)

CnH2n+2

(Synfuel)

Catalyst

O2

CnH2n+2

(Synfuel)

Porous

Cathode Porous

Anode Solid YSZ

Electrolyte

O2_

O2_

O2_

O2_

O2_

e- H2O

and

CO2

H2O CO2

Catalyst

2O2_

O2 + 2e_

H2

CO

n[CO2 + 2e_

CO + O2_ ]

n[H2O + 2e_

H2 + O2_ ]

Triple

Region

H

O=

e-

e- O

H H

Electrocatalyst

Cathode

H O=

What configurations with high-temperature

power sources are possible?

How would they compare with synthetic

hydrocarbon production using high-temperature

thermochemical H2 from water, and reverse

WGS CO from CO2?

3(H2O)

S-I

Thermochemical

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O

1.2 GJ of H2 to produce 1.0 GJ synfuel

S-I to Hydrogen, WGS to CO,

F-T to Synfuel

Heat

1

CO

and

H2

6 H atoms

2 H atoms

3(H2O)

S-I

Thermochemical Heat

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2(H2O) CO2

Elec

Electrolysis of

H2O and CO2


F-T to Synfuel

Electrolysis to Hydrogen and CO,

F-T to Synfuel

Heat

1 2

CO

and

H2

CO

and

H2

6 H atoms 4 H atoms 2 H atoms

2 H atoms 2 H atoms

3(H2O)

S-I

Thermochemical Heat

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2(H2O) CO2

Elec

Electrolysis of

H2O and CO2

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

9H2 + 8CO2 C8H18


Elec


F-T to Synfuel


F-T to Synfuel


F-T Polymerization to Synfuel

Heat Heat

1 2 3

CO

and

H2

CO

and

H2

Electrolysis of

H2O, CO2

and electro-

thermo-catalysis

of CO

6 H atoms 4 H atoms 2 H atoms

2 H atoms 2 H atoms

2 H atoms -CH2-

H2O CO2

2 H atoms 3(H2O)

S-I

Thermochemical Heat

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2(H2O) CO2

Elec

Electrolysis of

H2O and CO2


F-T to Synfuel


F-T to Synfuel



Heat

1 2 3

CO

and

H2

CO

and

H2

6 H atoms 4 H atoms

2 H atoms 2 H atoms

3(H2O)

S-I

Thermochemical

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


Heat

CO

and

H2

6 H atoms

2 H atoms

3(H2O)

S-I

Thermochemical

H2

CO2

Reverse

WGS

CO

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


O2 3

2

H2O

H2O

Heat

2H2

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

9H2 + 8CO2 C8H18


Elec

Heat

Electrolysis of

H2O, CO2

and electro-

thermo-catalysis

of CO

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

9H2 + 8CO2 C8H18


-CH2-

H2O CO2

2 H atoms

2 H atoms 3(H2O)

S-I

Thermochemical Heat

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2(H2O) CO2

Elec

Electrolysis of

H2O and CO2


F-T to Synfuel


F-T to Synfuel



Heat

1 2 3

CO

and

H2

CO

and

H2

6 H atoms 4 H atoms

2 H atoms 2 H atoms

3(H2O)

S-I

Thermochemical

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


Heat

CO

and

H2

6 H atoms

2 H atoms

3(H2O)

S-I

Thermochemical

H2

CO2

Reverse

WGS

CO

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


O2 3

2

H2O

H2O

Heat

2H2

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

9H2 + 8CO2 C8H18


Elec

Heat

Electrolysis of

H2O, CO2

and electro-

thermo-catalysis

of CO

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

9H2 + 8CO2 C8H18


-CH2-

H2O CO2

2 H atoms

Heat

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2(H2O) CO2

Elec

Electrolysis of

H2O and CO2

CO

and

H2

4 H atoms

2 H atoms

Heat

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2O O

2(H2O) CO2

CO H2

Elec

Electrolysis

membranes

2H2 CO

O2 3

2

H2O

2 H atoms 3(H2O)

S-I

Thermochemical Heat

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2(H2O) CO2

Elec

Electrolysis of

H2O and CO2


F-T to Synfuel


F-T to Synfuel



Heat

1 2 3

CO

and

H2

CO

and

H2

6 H atoms 4 H atoms

2 H atoms 2 H atoms

Heat

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2(H2O) CO2

Elec

Electrolysis of

H2O and CO2

CO

and

H2

4 H atoms

2 H atoms

Heat

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

17H2 + 8CO2 C8H18 + 8H2O


2O O

2(H2O) CO2

CO H2

Elec

Electrolysis

membranes

2H2 CO

O2 3

2

H2O

3(H2O)

S-I

Thermochemical

CO2

Reverse

WGS

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


Heat

CO

and

H2

6 H atoms

2 H atoms

3(H2O)

S-I

Thermochemical

H2

CO2

Reverse

WGS

CO

Fischer-Tropsch 1

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

25H2 + 8CO2 C8H18 + 16H2O


O2 3

2

H2O

H2O

Heat

2H2

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

9H2 + 8CO2 C8H18


Elec

Heat

Electrolysis of

H2O, CO2

and electro-

thermo-catalysis

of CO

-CH2-

Fischer-Tropsch 2

CH2 + CH2 + . . . + CH2 + H2

CnH2n+2 (synfuel)

For Octane:

9H2 + 8CO2 C8H18


-CH2-

H2O CO2

2 H atoms

O2 3

2

O

H2

O

CO

O

CH

CH2

Electrolysis

membrane

What do the electrolysis an electrocatalytic reactions

look like?

What are the possible steric effects that may help

define the specific catalytic formulations that can

permit reduction of CO in the presence of hydrogen?

O2_

Solid oxide

electrolyte

O2_

O2_

O2_

O2

_

O-C-O C-O

O

H H H-C-H

Cathode

Catalyst

Out

C-H

e-

Porous cathode Gas in

O-C-O*

C-O*

C-H

Cathode

Catalyst e_

e_

e_

O2_

A-B* = metastable state of A-B

CO2 + 2e- CO + O2- +2e- + nXHm CHn.m +nX + 2O2-

Cathode Cathode

Electrocatalysis

e- e-

H2O + + 2e- 2H + O2-

Cathode

e-

O2

X = C or O or H

Possible electro-catalytic and thermo-catalytic sterics, metastable states and reaction

schemes. This is where the research lies for electrochemical replacement of both

reverse water gas shift and the Fisher-Tropsch reactions thermochemistry.

Solid Oxide Fuel Cell Examples

Ceramatec solid oxide fuel cell/electrolyser

Planar cells

120 kWe tubular solid oxide fuel cell. The system design can essentially be the same for a synthetic

hydrocarbon production system reversing the electrochemical process.

Courtesy: Siemens Westinghouse

Documents

Electrochemical synthetic hydrocarbons - Rambach - for printing with title page