Stephan Rieke

SolarFuel GmbH – Stephan Rieke: Solar Fuels and Power-to-Gas technologies

CPE Lyon, 28.9.2012

Stephan Rieke

Structure:

Challenges of the electricity system through the integration of renewable

energies

Possible storage solutions as an integration puzzle

Renewable Methane as a systematic approach – bidirectional

combination of electricity and gas grids

Status: activities of SolarFuel – particular project realisation

-3-

Real Storage capacity Average power Consumption

Storage capacity of the natural gas grid in Germany lasts for 2000 hrs, storage capacity of the electricity grid last for only 0,6 hrs Energy consumption and storage capacity in Germany, 2008

1) fuel, diesel, kerosine 2) high differences from season to season 3) pump accumulator power plants 4) 46 underground gas storage / plus 72 TWh in construction /

planning 5.) stockage of fuel, diesel, kerosine and fuel oil EL 6.) related to average capactiy

source: ZSW

707

930

619

Calculated storage

capacity 6

71

81

1062

TWh/a GW

2505

2174

0,043

TWh

3,1005

2,0004

0,63

h

Electricity Natural gas Liquid fuel1

-5-

Power to Gas: Comparison of storage capacity and duration between different energy storage technologies

Chemical storage of methane could be interesting due to time, cost, capacity and existing infrastructure.

SolarFuel GmbH

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Power-to-Gas Concept is linking the electricity and natural gas networks

Interconnection with different CO2 resources by producing renewable methane (SNG- Substitute Natural Gas)

Source: SolarFuel/Specht, ZSW

CCPP /

µ-CHP

CO2

buffer

Grid Gas distribution

system

Electrolysis /

H2 buffer

H2

CH4

POWER GENERATION

ELECTRICITY STORAGE

Gas

storage

Solar

Wind

H2

Methanation

Heat

CO2 CO2

CCPP: Combined Cycle Power Plant; µ-CHP: micro Combined Heat and Power Plant

Atmosphere

Biogas/sewage

Breweries

Steel, cement

Chemical plants

Industry

Heating

Fuel Chemistry

SolarFuel GmbH

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Absorption- / Desorption

Electrolysis

Synthesis

Air with CO2

Water

CO2

Air without CO2

Oxygen

H2

Methane Solar energy PV/

Windpower Electricity

other CO2 resources or utilisation of CO2 is possible

other H2 resources or utilisation of H2 is possible

Renewable methane (RM): Absorption/electrochemical desorption of CO2 , reduction of H2O to H2 and followed reduction of CO2 by hydration would be the favourable solution

Basic plant concept of CO2 absorption by air inlet, 2009, combines different approaches

source: SolarFuel

Detailed analysis of process shows ideal process realisation for independent applications like off-grids

stuff energy

• Fully satisfied

hydrocarbons

• Best Energy -to -

C-Relation

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SolarFuel GmbH

lyon_28_9_2012_en.ppt

Experiences with CO2-Conversion to methanol by H2-Reduction and Solar electricity at the ZSW leads to Methanation of CO2 in the 90`s PV Generator including column reactor for CO2 absorption by air scrubbing 1998 for methanol production

Source: ZSW, Specht et. al.

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Thermodynamical Optimum (idealised process) methanation

• 4H2 + 1CO2 → CH4 + 2H2O

• 12 kWh → 10 kWh

• 100% → 83%

• 4m3 + 1m3 → 1m3 + 0 (condensed)

Real Process SolarFuel

• The challenge will be the level of methanation:

– A level of methanation of over 90% will be reached

– This permits a direct feed of the SNG into the gas distribution system

– Total overall efficiency will be >60% electricity to gas, or > 80% by using gas and waste heat for industrial,

domestic applications.

Methanation and Electrolysis: Basic industrial technology units are the central processes

source: SolarFuel

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SolarFuel plant converts surplus of electricity from wind or pv power into renewable methane/SNG (substitute natural gas) Flow chart SolarFuel demonstration plant ,2009

Feed gas stoichiometry adapted for optimized methanation operation conditions.

Addition of steam to avoid carbon depositions/catalyst deactivation.

Methanation heat utilization at T > 200 °C possible

source: ZSW/SolarFuel

Electrolysis Methanation M

M

M O2

Pel H2O

Pel

CO2

H2O

Q

Q

H2O Q Pel

Substitute

Natural Gas

(SNG)

H2

Heat exchange unit

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The α-plant produces a norm compliant substitute natural gas according to DVGW G260/262 and DIN 51624 N in two containers

Technology Scheme

Container 1: CO2-Production

Container 2: fuel synthesis

CO2-buffer

P/C

FIC

CO2 supply Electrodialysis

CO2-Absorber

2-Bench-

Storage

P/C

Gas dryer CH4 buffer

Fuel-filling

CH4-Synthesis

Car

Fuel

nozzle

DI-Cartridge

M

M

M

H2-Production

Hydrogen

generator

FIC

Gas mixer M

M

Air

Exit air

Water

Process temperature control

Reactor

Evaporator

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The SolarFuel demonstration plant in Stuttgart uses CO2 from the air for off-grid/remote area application or a non-concentrated CO2 resource

X ray image of the plant, 2009

Option: CO2 from biogas plants (>7300 plants, 2,5 GWel, 2011), potential of approx. 60-70 TWh SNG 2011,

other CO2 resources are bioethanol, brewery, sewage treatment or industry (lime stone, chemical processes).

source: SolarFuel

SolarFuel GmbH

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80

85

90

95

100

13400 17000 20600 24200 27800 31400 35000

Test Duration [h]

CH

4-C

on

ten

t [v

ol-

%]

0

5

10

15

20

CO

2-,

H2-C

on

ten

t [v

ol-

%]

CH4

CO2

H2

0 1 2 3 4 5 6

CO2 + H2 (via Electrolysis) SNG

Gas Composition during Steady State Operation of the demo plant

Source: Dr. M. Specht, ZSW

Reactor concept: Fixed bed reactor

with recycle loop and intercooler

Feed: CO2 20 Vol.%db, H2 80 Vol%db

T = 250 - 550 °C, p = 7 barabs, SV = 2000 l / (lcat * h)

No downstream processing!

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Conversion efficiency will exceed 60%, SNG will be injected directly into the natural gas network, total efficiency >80% (gas + heat) Vol. %, G262, DIN 51624 compliant

Electricity

Electrolyser

11.7%

26.7% Usefull Heat <80°

Usefull Heat >200°C

61,6%

Substitute Natural Gas

(SNG)

100%

Electricity

Compression of CO2

98.9%

1.1%

source: SolarFuel

Conversion

Gas content before and after methanation, Vol. %, Wobbe matching according biogas to grid management

CH4-rich

Product-Gas (SNG) Feed-Gas

CO2

20.5

H2

79.5 CH4

90,1

CO2

5.3

H2

4.6

Reaction of synthesis

Reduction of volume 5:1

SolarFuel GmbH

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Renewable methane (RM) to provide an assured, planable energy supply by renewable electricity

Multi dimensional value of RM in the system platform “gas network” according

(peak power generation versus fuel aplication )

Long range mobility

with existing CNG

filling stations

Renewable Methane

Produced by

Power to Gas

devices

Shipment (LNG)/airfuel

(GTL)

Power generation by

ccpp/gasturbine systems

heating

Green chemistry

Pipeline Transport

LNG

Transport

Chiller/cold

Gas storage

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CO2-Cycle in existing gas network/power turbine infrastructure with ptg oxygen streams

sourcee: SolarFuel et al.

PV Power

CO2

Electricity network

CO2

H2

Decentralized chp

Gas network

Gas turbine

CO2 -Tank

Elektrolysis/H2

-Tank

CO2

H2

CH4

Methanation

Wind

heat

O2

CO2

electricity

OxiFuel*

Gas boiler

CH

4

O2

O2

Tank

CO2

Tank

Long range mobility

Heating

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Solar Fuel GmbH

Pipeline of PtG Projects up until large scale realisation in the real market by Audi through 6,3 MWel plant Consequent steps in the development of plants by SolarFuel

Werlte

Stuttgart

2009 Alpha-Anlage Morbach

Beta-plant

Quelle: SolarFuel

2013

Hersfeld

2010- plant with biogas supply

IWES 2012

250 kW, ZSW 2012

2011

ZSW 2009

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Power to Gas - PtG250 – Alkaline Electrolysis (AEL) device, ZSW

-41-

Solar Fuel GmbH

State of development for AEL: Status of Hysolar Project 1995

State of Technology in 1995: Electrolyser with direct PV coupling in intermittent/dynamic operation

Quelle: ZSW

e-gas-plant

Linking of the electrical and gas grid

Pilot project of audi with windturbines of 4* 3,6 MW

Elektrolyse

H2-Tank

CO2-Tank

Water 4.600 t H2O

Oxygen 4.000 t O2

520 t H2

Natural gas cars

CNG

Gasnetz

water 2.000 t H2O

CO2 from

► Biomass-, gas

Fuel cell FCEV Electric

BEV, PHEV

53.000 MWh

27.600 MWh

Power generation

Combined heating pp

2.800 t CO2

Methanation CO2 + 4H2 → CH4 + 2H2O

electricity

1.000 e-trons

+ 1.500 A3 TCNG

1.000 e-tron

Production

of the car

20.100 MWh

*all values per year

H2

1.500 A3

TCNG

Gas storage

120 t CH4

lyon_28_9_2012_en.ppt -48-

Life cycle analysis of the Audi A3 TCNG Life cycle range in total: 200.000 km

CO2-

Äquivalente

[g/km]

CO2-Emissions tank-to-wheel

CO2-Emissions of car

manufacturing

CO2-Emissions well-to-tank

petrol CNG

BioMethane

BEV (Wind power)

BEV (EU-mix)

Conclusion: a wind powered A3 ICE TCNG model has the same

environmental benefit like a BEV powered with wind power

- 85% CO2

(well-to-wheel)

e-gas (Wind power)

-50-

Solar Fuel GmbH

Contact:

SolarFuel GmbH

Stephan Rieke

+49 (0) 711 – 22 96 45 50

+49 (0) 151 18 05 44 50

rieke@solar-fuel.net

If the wind of change is blowing,

Somebody is building up walls,

And somebody is building wind mills.

Laotse