Techno-economic and environmental assessment …avnir.org/documentation/congres_avnir/2017/PPT/Procedes...Techno-economic and environmental assessment of electrochemical reduction

Techno-economic and environmental assessment of electrochemical reduction of

CO2 to formic acid

University of Mons (Belgium)

Faculty of Engineering

Thermodynamics Department

[email protected]

Conference [avniR]November the 9th – Lilliad, Lille, FRANCE

Remi CHAUVY, Nicolas MEUNIER, Diane THOMAS and Guy De WEIRELD

University of Mons 2CHAUVY R. | Conference avniR – Lilliad, Lille, FRANCE – 09/11/2017

Context: Carbon capture and Utilization

Transport23%

Industry 19%

Residential6%

Services3%

Other* 7%

Industry 18%

Residential 11%

Services 8%

Other* 5%

Electricity and heat42%

Global anthropogenic CO2 emissions by sector (2014) [1]

Total: 37 GtCO2

* Other: agriculture/forestry, fishing, energy industries otherthan electricity and heat generation, and other emissions notspecified elsewhere

Industrial sector: 20 to 25% of total CO2 emissions

Cement sector: Largest non-combustion sourcesof industrial CO2

5 to 7% of total CO2 emissions 2/3 of released emissions comefrom the decarbonation step:unavoidable

[1] IEA, CO2 Emissions from fuel combustion Highlights, IEA (2015)

University of Mons 3

Context: Carbon capture and Utilization

Fuels

methane, methanol, ethanol, etc.

Intermediates & Chemicals

formic acid, acrylic acid, etc.

Polymers

polycarbonates, etc.

Inorganic and organic carbonates

calcium carbonate, etc.

Carbamates

Carboxylates and lactones

Biomass

Microalgae

ConversionChemicals

Mineralization (Ex-situ mineral carbonation technology)

BiologicalElectrochemical reduction

etc.

SequestrationGeological storage

Saline aquifersDepleted oil and gas fieldsIn-situ mineral carbonation

technology

Capture and Storage (CCS)

Capture and Utilization (CCU)

Amine scrubbingMembrane

Pressure Swing Adsoptionetc.

CCS/CCU CCU

CO2 capture and purification

CHAUVY R. | Conference avniR – Lilliad, Lille, FRANCE – 09/11/2017


Selecting emerging CO2 utilization products for short-mid-term deployment

CO2-based compound

CO2-conversion process

Score

Urea Organic synthesis *****Methanol Hydrogenation ****Methane Hydrogenation ****Microalgae Biological process ***Calcium carbonates

Mineral carbonation ***

Ethanol Microbial process **Sodium carbonates

Mineral carbonation **

Syngas Dry reforming *

CO2-based compound

CO2-conversion process

Score

Polycarbonates Organic synthesis *****

Formic acidElectrochemical reduction

****

Dimethyl carbonate

Organic synthesis ***

Salicylic acid Organic synthesis **

IdentificationMore than 100 conversionpathways & projects identified,described and classified

STEP 1: Pre-selectionReduction of the panel to a

shortlist

STEP 2: SelectionMulti-criteria assessmentusing an original doubleweighted matrix to select 3/4routes that will be modelled

Low unit price but significant market volume

High unit price but low market volume


University of Mons

Key points:

• Liquid at ambient condition (ease of storage)

• Efficient hydrogen storage molecule

• Global demand of 1 million tons/year in 2016

• Commercially available in solutions of various concentrations (85 - 99 wt%)

• Generates 600 millions €/year

Applications:

• Energy storage (hydrogen storage molecule )

• Chemicals (C1 building block)

• Pharmaceuticals (preservative and antibacterial agent)

• Textiles (leather and tanning industries, etc.)

5

Formic acid Utility & Applications



Approach structure

Raw Material

Acquisition

Material processing

Manufacture and

assembly

Use and service

Retirement and recovery

Treatment and disposal

Cradle

Grave

Coupling Process Engineering tool and LCA

Gate to gate approach

Operating parametersvary to define the mostinteresting parameterfrom environmentalpoint of view

Multi-objective optimization

Process Modelling Aspen Plus

Life cycle Inventory

Environmental burdens

Excel / Aspen

Economics

CAPEX & OPEX

Multi objective optimization

LCA

IA


University of Mons

Electro-reduction of CO2 into formic acidDescription of the process

7

Sep

arat

ion

Sep

arat

ion

un

itMem

bra

ne

-

CO2 recycled Formic acid85 wt%

H2O recycled

Mixture:CO2, H2O, HCOOH, H2

O2CO2

H2O

H2

+

H2O

H2O – HCOOH

CO2 – H2

Electrochemical reactor

Process of electro-reduction of CO2



Anolyte

+

O2 (g)

Anolyte

Ion exchange

membrane

Anode

catalyst

Cathode

catalyst

Catholyte

+

Formic acid

+

H2

+

CO2 unreacted

Catholyte

+ CO2

Basic conditions

Cathode reactionsCO2 (aq) + H2O + 2e- ↔ HCOO- + OH-

2H2O + 2e-↔ H2 (g) + 2OH-

Anode reaction4OH-↔ 2H2O + O2 + 4e-

Acidic conditions

Cathode reactionsCO2 (aq) + 2H+ + 2e- ↔ HCOOH2H+ + 2e-↔ H2 (g)

Anode reactions2H2O ↔ O2 + 4H+ + 4e-

TotalH2O(l) + CO2(g) ↔ HCOOH(l) +0.5 O2(g) (main reaction)H2O(l) ↔ 0.5 O2(g) + H2(g) (side reaction)





Water-formic acid equilibrium curve at 1 bar

Water-formic acid mixture: Formation of an azeotropeRequires special methods to facilitate their separation

Equilibrium curve: ideal case

Azeotrope




User define model to implement the electrochemical reactor andmembrane unit under Aspen Plus

1) Electrochemical reactor unit: conversion reactor together with a splitseparation : Efficiency: 15% [2]

2) Membrane process: split unit : H2/CO2 separation efficiency: 85% [2]

Separation of the water-formic acid mixture:• Pressure Swing Distillation: Option 1• High-pressure separation: Option 2• Vacuum distillation• Rectification adding a third component

[2] A. Robledo-Diez, 2014, Life Cycle Assessment on the conversion of CO2 to formic acid (Master Thesis).

Electro-reduction of CO2 into formic acidProcess Simulation: Aspen Plus v9



Effect of the pressure on the azeotrope

“Shift” of the azeotrope point

Option 1: Pressure Swing Distillation

1 bar3 bar

water formic acid

xaz(3bar)

xaz(1 bar)

3 bar

1 bar

Electro-reduction of CO2 into formic acidProcess Simulation

7 bar

water

formic acid

Option 2: High pressure Distillation



Electro-reduction of CO2 into formic acidProcess Simulation: Study case

BAT cement plant:

• Best Available Technology

• Production of 3 000 tpd clinker (main consistuent of cement)

• Release 2 475 tpd CO2

• 1/3 due to the combustion

• 2/3 due to limestone calcination during the decarbonation step in the clinker burning process calcination (550 kgCO2 per t clinker)

• Conversion of 5% of CO2 emissions of 1 BAT cement plant: 125 tpd CO2



Flowsheet: Conversion of 5% of CO2 emissions of 1 BAT cement plantOption 1: Pressure Swing Distillation

Formic acid@85wt%

125 tpd

51 tpd

35 tpd

3 bar

1 bar

Water-formic acid separation unit


Membrane unit

Simulations with Aspen Plus v9• Thermodynamic model : UNIFAC-

Dortmund for liquid phase,Redlich-Kwong equation of statefor gaseous phase

• Acidic condition considered

Electro-reduction of CO2 into formic acidProcess Simulation: Option 1



Flowsheet: Conversion of 5% of CO2 emissions of 1 BAT cement plantOption 2: High pressure Distillation

Formic acid@85wt%

125 tpd

51 tpd

35 tpd

7 bar

Water-formic acid separation unit


Membrane unit

Simulations with Aspen Plus v9• Thermodynamic model : UNIFAC-

Dortmund for liquid phase,Redlich-Kwong equation of statefor gaseous phase

• Acidic condition considered

Electro-reduction of CO2 into formic acidProcess Simulation: Option 2



[3] A. Domingues-Ramos et al., 2015, Global warming footprint of the electrochemical reduction of carbon dioxide to formate.

Electro-reduction of CO2 into formic acidProcess Simulation: Performance indicators

Option1 Option2

Mass balances

(tpd per t FA@85

wt% produced)

CO2 inlet (CO2FEED) 0.82

H2O inlet

(H2OREACT +

H2OSUP)

0.562

HCOOH

85%produced1

H2 produced 0.01 0.01

O2 produced 0.45 0.45

Option1 Option2

Energy requirements

(per t FA@85 wt% produced)

Electricity (without

elect. reactor)

(MWh)

0.824 0.837

Electricity (elect.

reactor)[3](MWh)6 - 8

Steam (reboiler)

(MJ)91 371 278 608

Additional consideration

- Technical constraints(diameter of thecolumns, % FArecirculated in thereactor etc.)

- Energy requirementsSteam reboiler

Option 2 non validated

Environmental burdens !



• Goal: Environmental evaluation of the process

• Identification of environmental burdens

• Comparison with fossil-based formic acid

• System boundaries: Gate-to-gate LCA approach

• Functional unit: production of 1 ton FA @85wt% via electro-reduction CO2

Electro-reduction of CO2 into formic acidEnvironmental assessment

CO2 capture processCement plant FA plant

Formic acid synthesis

Cement production

CO2 capture(MEA based) H2 11 kg

electricity & heat supplycooling water

construction materials

water supply562 kg

FA @85wt%1 000 kg

emissions & wastes

O2 450 kgCO2 supply820 kg

Clinker

Flue gas

Chemical (MEA) Chemicals Anolyte/Catholyte

System boundaries




• Allocation approach: Price based allocation

• Formic acid (85wt%) : 94 %

• Oxygen : 0.7 %

• Hydrogen : 5.3 %

• Feedstock and utility supply

• CO2 supply: considered to be reused instead of being stored: no additionalenergy required to capture CO2 / environmental impact of CO2 supply neglected

• Water supply

• Electricity supply: European mix energetic ENTSO-E

• Heat supply: Steam generated by natural gas boiler (76%); rest of oil as feedstock

• Chemicals supply: HCl (catholyte), NaCl (anolyte)

• Infrastructures: Literature data

• Environmental impacts of supply processes: LCA-database EcoInvent v3.3




per t FA@85 wt%

Units

Infrastructure

Electrochemicalreactor

Mild steel cell body 0.186kg

Tinned copper plate 0.013Cathode Tin granulate 1.62 kgAnode Stainless steel mesh 4.16 g

EnergyElectricity 6.82 MWhHeat 91 371 MJ

Chemicals

Catholyte HCl 2.04 kgAnolyte NaCl NaCl 2.04 kgWater 0.562 tCO2 (captured) 0.82 t

Valuableproducts

(final products)

Formic acid 1 tHydrogen 0.01 tOxygen 0.45 t

• Life cycle Inventory [3]

• Functional unit: production of 1 ton FA @85wt% via electro-reduction CO2

[3] A. Domingues-Ramos et al., 2015, Global warming footprint of the electrochemical reduction of carbon dioxide to formate.




• Life Cycle impact assessment : Method : ReCiPe Midpoint (H) V1.13 /Europe

0

10

20

30

40

50

60

70

80

90

100

Climate change Ozonedepletion

Terrestrialacidification

Freshwatereutrophication

Human toxicity Waterdepletion

Metaldepletion

Fossil depletion

Steam Water Infrastructure Electricity Chemicals


University of Mons

Emission factors

Steam (kg CO2 eq / MJ) [4]

Lignite Hard coal Heavy fuel oilLight fuel

oil

Fuel mix EcoInvent

v3.3NG Bio

123.70 123.51 103.09 100.22 81.57 79.77 5.97

Electricity(g CO2 eq /

kWh))

Coal 1 038Oil 704

ENTSO-E 463Gas 406

Photovoltaics 55Geothermal

power45

Wind power 7.3Nuclear 6

Hydroelectricity 4

20

• Global warming footprint (GWP)

[4] Petrescu L. et al., 2016, Life cycle analysis applied to acrylic acid production process with different fuels for steam generation.

Worst case scenario20 531 kg CO2 eq per t FA

Best case scenario669 kg CO2 eq per t FA

As usual11 994 kg CO2 eq per t FA

• GWP of classical production from methyl formate: 3 305 kg CO2 eq




Flowsheet: Conversion of 5% of CO2 emissions of 1 BAT cement plantOption 1: Pressure Swing Distillation

Electro-reduction of CO2 into formic acidA way to make the process greener

(& economically viable)

Heat integration

Reduction of steam requirementsat the reboiler

Water consumption

Reduction of water consumptionIncrease CO2 solubility

Reduction of environmental impacts of water-formic acid separation

Reduction of the costs !



Perspectives

• High energy requirements to ensure the sustainability of the process BUTthe integration of RE lower the environmental impacts

• Further investigation regarding the water-formic acid separation processin order to select the most performant option

• Technico-economic evaluation of the different options and optimizationof the overall process

• Environmental assessement of the different options

• Aim to propose an environmentally friendly, integrated and optimizedCO2 conversion process applied to the cement sector !


Remi CHAUVY

[email protected]

Acknowledgements to the University of Mons (UMONS, Belgium) and the European Cement

Research Academy (ECRA) for their technical and financial supports.

Nicolas MEUNIER acknowledges the Belgian National Fund for Scientific Research (F.R.S.-FNRS).

Thank you for your attention


APPENDIXCement plant: CO2 capture

CaCO3 + heat → CaO + CO2↑

CO2 concentrations in cement industry flue gases• 20-30% (conventional cement kilns)• 70-90% (oxyfuel cement kilns)


Documents

Techno-economic and environmental assessment …avnir.org/documentation/congres_avnir/2017/PPT/Procedes...Techno-economic and environmental assessment of electrochemical reduction