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Hydrogenation of CO2 as a means to reduce greenhouse-gas emissions? A

case study

Conference Paper · January 2011

DOI: 10.13140/2.1.4351.0725

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HYDROGENATION OF CO2 AS A MEANS TO REDUCE GREENHOUSE EMISSIONS?

A CASE STUDY

Authors: Luis A. Robles Macías and Mustapha Aminu

11th International Conference on Carbon Dioxide Utilization – Dijon, June 2011

Pathways for CO2 valorization

Direct Use ConversionDirect Use

No transformation

• Industrial Use : food industry refrigeration gas

Insertion

•Organic synthesis: Urea, salicylic acid, polycarbonates…

Chemical bond cleavage

•Hydrogenation:

Biological conversion

•Micro-algae

Conversion

industry, refrigeration gas... salicylic acid, polycarbonates…

•Dry reforming:

CO2 + H2

CO2 + CH4

•Enhanced Oil Recovery, Enhanced Coal Bed Methane

•Mineralisation: CO2+MO MCO3

•Electrolysis:

•Photo-electrocatalysis: •Biocatalysis

CO2 + power

•Photo-electrocatalysis:

•Thermolysis:

Biocatalysis

CO2 +power

sunlight

CO2 T > 1500 K

CO2 hydrogenation

Reaction of CO2 and H2 with the aid of a catalyst under suitable conditions

CO2 source

captured CO2

Hydrogenation Plant

PRODUCTS:methanolmethanol, ethanol, methane, gasoline, etc

hydrogenNon‐fossil source of  gasoline, etc

hydrogen

Open questions

Carbon dioxide can be chemically transformed from a detrimental greenhouseCarbon dioxide . . . can be chemically transformed from a detrimental greenhousegas causing global warming into a valuable, renewable and inexhaustible carbonsource of the future allowing environmentally neutral use of carbon fuels and derivedhydrocarbon products. (Olah et al. 2009)

Of course, ‘whole process’ energy balances and economics remain a critical issueOf course, whole process energy balances and economics remain a critical issue— as indeed is the case for any overall vision of energy futures. (Jiang et al. 2010)

Can CO2 hydrogenation meet both environmental and economic targets?

Challenge #1: High stability of CO2

carbon

Source:Lange’s Handbook of Chemistry; own work.

kJ / m

ol of c

CO2 is thermodynamically more stable than the products obtained by hydrogenation

Challenge #2: Sourcing of Hydrogen

Distribution of energy requirements for synthesizing methanol from atmospheric CO2 and renewable hydrogen

Source:Pearson et al., 2009

H2 production consumes by far the greatest amount of energy required by CO2 hydrogenation

Case Study

Hydrogenation of CO2 to methanol 

Three types:

500 MWe power plant

y g f 2demonstrated by CRI (Iceland) and Mitsui (Japan)

captured CO2

yp1. Coal2. Natural gas3. Geothermal

Methanol Plant

METHANOLNon‐fossil source of electricity

H2

electricity

water

anode catode

Scope of work

Assess technical feasibility only, without going into economic t distudies

Only heat & material balances

Theoretical calculation of: Amount of H2 required to hydrogenate emitted CO2 to methanol Amount of electricity required to produce H2 Amount of methanol produced

Six scenarii: Three types of power plants: coal, natural gas and geothermal Two values of electrolysis efficiency: current, and long termy y , g

Assumptions

1 Optimistic on CO to methanol hydrogenation1. Optimistic on CO2-to-methanol hydrogenation Methanol yield = 100% (perfect stoichiometry) Heat released by methanol synthesis is enough to satisfy all energy needs of

methanol plant (compression distillation ) + energy needs of CO2 capturemethanol plant (compression, distillation...) + energy needs of CO2 capture

2. Optimistic on CO2 capture technology Low energy consumption, fully satisfied by excess energy from methanol plant All emitted CO2 is captured and purified for hydrogenation

3. Optimistic on electrolysis technology Current efficiency of electrolysis: 67% Improvement of electrolysis efficiency over time up to 90% (by 2020 ?) Improvement of electrolysis efficiency over time up to 90% (by 2020 ?) Water electrolyzers available industrially at large scale

Coal power plant

2000

3000

Energy balance

500 MWeoutput4,500 

t/d of 0

1000

2000

10,000 t/d of CO2

t/d of coal

-2000

-1000

0

-3000Power out (MWe)

Power in (MWe)

7,273 t/d of 

1,363 t/d of H22,844 MWe

MeOH out (MWth)

Methanol METHANOL

2,844 MWeinput Plant

H2 production consumes 5.7 times the amount of electricity generated by the power plant

Coal power plant, improved electrolysis

2000

3000

Energy balance

0

1000

2000

500 MWeoutput4,500 

t/d of

-2000

-1000

0

10,000 t/d of CO2

t/d of coal

-3000Power out (MWe)

Power in (MWe)

1,363 t/d of H2

MeOH out (MWth)

7,273 t/d of Methanol 2,116 MWeMETHANOLPlant

2,116 MWeinput

H2 production still consumes 4.2 times the amount of electricity generated by the power plant

Natural gas power plant

1500

2000

Energy balance

0

500

1000500 MWeoutput1,900 

t/d of

-1500

-1000

-5005,200 t/d of CO2

t/d of NG

-2000 Power out (MWe)

Power in (MWe)

MeOH out (MWth)MeOH out (MWth)

3,782 t/d of Methanol 

709 t/d of H21,478 MWe

METHANOLPlant1,478 MWe

input

H2 production consumes about 3 times the amount of electricity generated by the power plant

Natural gas power plant, improved electrolysis

1500

2000

Energy balance

0

500

1000500 MWeoutput1,900 

t/d of

-1500

-1000

-5005,200 t/d of CO2

t/d of NG

-2000 Power out (MWe)

Power in (MWe)

MeOH out (MWth)

3,782 t/d of Methanol 

709 t/d of H21,100 MWe

METHANOLPlant1,100 MWe

input

H2 production still consumes 2.2 times the amount of electricity generated by the power plant

Geothermal power plant

400

500

600

Energy balance

100

200

300

400

500 MWeoutput

-200

-100

0900 t/d of CO2

-300Power out (MWe)

Power in (MWe)

MeOH out (MWth)MeOH out (MWth)

655 t/d of Methanol 

123 t/d of H2255 MWe

METHANOLPlant255 MWeinput

H2 production consumes only about half of the electricity generated by the power plant

Geothermal power plant, improved electrolysis

500

600

Energy balance

100

200

300

400

500 MWeoutput

-200

-100

0

100

900 t/d of CO2

-300

00

Power out (MWe)

Power in (MWe)

MeOH out (MWth)

655 t/d of Methanol 

123 t/d of H2190 MWe

METHANOLPlant190 MWeinput

H2 production consumes only 38% of the electricity generated by the power plant

Conclusions

Industrial demonstration of CO2 hydrogenation to methanol is underwayis underway

Thermodynamics dictate that much energy is necessary to hydrogenate CO2hydrogenate CO2

Sourcing of clean hydrogen from a renewable source is a key challengeg

Hydrogenation of CO2 as a way of reducing GHG emissionsmay make sense but only if:

1. non-fossil hydrogen is abundantly available,2. CO2 is efficiently captured, and3. the emitter has a low CO2 intensity, e.g. geothermal power plant

While CO2 hydrogenation may have useful applications, Total is focusing on other, possibly more promising, pathways of CO2 valorization

Current research at Total

Organic carbonatesI t th ti CO l l t i i i d Insert the entire CO2 molecule to minimize consumed energy

High added-value chemicals Dialkylcarbonates, cyclic carbonates

CO2 thermolysis2 y Reduction of CO2 into CO and O2 at very high temperature Intrinsically more efficient than H2O thermolysis Collaboration underway with DLR on solar thermolysisCollaboration underway with DLR on solar thermolysis

Photo-electrocatalysisPhoto-electrocatalysis Focus on solar splitting of H2O instead of CO2 Produced hydrogen could be used for CO2 conversion

Thank you!Thank you!R fReferences

Jiang, Z., Xiao, T., Kuznetsov, V. L., Edwards, P. P. Turning carbon dioxide into fuel. Phil. Trans. R. Soc. A 2010 368, 3343-3364

Olah, G. A., Goeppert, A. & Surya Prakash, G. K. 2009 Chemical recycling of carbon dioxide tomethanol and dimethyl ether: from greenhouse gas to renewable, environmentally carbon neutral fuels and synthetic hydrocarbons. J. Org. Chem. 74, 487–498.

Pearson, R. J., Turner, J. W. G. & Peck, A. J. 2009 Gasoline–ethanol–methanol tri-fuel vehicledevelopment and its role in expediting sustainable organic fuels for transport. In Low carbonvehicles 2009, Institution of Mechanical Engineers, London, 20–21 May 2009

Image creditsVerre eau gazeuse au jardin (resized). Author: Égoïté, via Wikimedia Commons. Licensed under CC-BY-SA.

Geological storage options for CO2 All rights reserved by CO2CRCGeological storage options for CO2. All rights reserved by CO2CRC.

Witherite Barium carbonate Cumberland England 1920. Author: Dave Dyet, via Wikimedia Commons.

Salt ponds, South Bay, SF. Author: Doc Searls, via Flickr. Licensed under CC-BY-SA.

Papain enzyme. Author: User:Mattyjenjen, via Wikimedia Commons.

CO2+H2O Emissions (Flein power station). Author: Dmitry Klimenko, via Flickr. Licensed under CC-BY-ND.

Methanol plant in Total Raffinerie Mitteldeutschland. All rights reserved by Total.

Schemas electrolyse h2o. Author: Nécropotame, via Wikimedia Commons. Licence Art Libre.

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