2+ -3 3 2 2Mg + 2 HCO MgCO + CO + H OStep 3:

+ 2+3 2 5 4 2 2Mg Si O (OH) + 6 H 3 Mg + 2 SiO + 5 H OStep 2:

- +2 2 3 3(g)CO H CO HCO + HStep 1:

Adsorption

CCUS within Energy SystemsMineral Carbonation

Absorption

Separation Processes Laboratory – Prof. Marco MazzottiInstitute of Process Engineering, ETH Zurich

www.ipe.ethz.ch

CO2 Capture and Storage at SPL

Climate change mitigation requires a net-zero-CO2 world, where we need to implement renewable energy sources, to capture CO2 and then either store it or re-use it.

The implementation of renewable energy sources requires different energy storage technologies to deal with short- and long-term generation dynamics.

1. L-economy

3. L-economyw/ CCS

2. L-economy w/ CCU

5. O-economy w/ CCU

6. O-economyw/ DAC-CU

7. O-economy w/ bio-energy

8. NET-economy w/ bio-energy and CCS: BECCS

9. NET-economy w/ DAC and CS: DACCS

po

siti

ve C

O2

emis

sio

ns

neg

ativ

e C

O2

emis

sio

ns

net

-zer

o C

O2

emis

sio

ns

4. L-economyw/ DAC-CS

Fossil (reduced) carbon

Oxidized carbon (CO2)

Synthetic (reduced) carbon

Biogenic (reduced) carbon

Renewable energy source

CO2 in the atmosphere

Distributed CO2 emissions

CO2 conversion plant

Direct air capture of CO2 from air (DAC)

Biomass treatment plant

Managed biomass growth

Post-combustion CO2 capture (PCC)

Underground CO2 storage

Point source CO2 emissions

Optimization tool determining the optimal design and operation of the H2 supply chain to minimize cost and/or CO2 emissions while satisfying a given H2 demand.

20

40

60

80

100

Ro

un

d-t

rip

eff

icie

ncy

[%

]

Flywheel Battery Pumped hydro

CAES P2H2 P2CH4

Characteristic storage time

minutes hours days to weeks weeks to months

Zurich

We aim at developing novel system paradigms and optimization techniques for the assessment of several decarbonization options from a system perspective.

Magnetic Suspension

Balance

Measuring adsorption isotherms

for pure components and gas mixtures

Adsorption Equilibria

CO2

onActivatedCarbon

Adsorption Kinetics

TI

PI

TIT

I PI

Column

TI

TI

TI

Vent

TIC

110 cm

85 cm

60 cm

40 cm

10 cm

TI

Breakthrough experiments

Investigation of mass and heat transfer

Modeling

Adsorption Processes Simulation Toolbox

Experimentalvalidation

2-column Fixed-Bed

Lab-scale setupfor operation of cyclic adsorption processes:

Pressure swing, PSA

Temperature swing, TSA

Vacuum swing, VSA

Optimization

Non-ConvexMulti-Objective

Optimization

Maximization of the process performance

under a set ofnon-linear and

non-convex constraintsSensitivity analysis

Optimization result

Numerical resolution of system of NPDAEs until

cyclic steady state

Carbon-free Fuel

CO2-free flue gas

Pre-combustion CO2 capturePost-combustion CO2 capture

Pressure (PSA) or Vacuum-Pressure (VPSA) Swing Adsorption processes

Temperature Swing Adsorption (TSA)Processes

CO2 capture from a moist N2/CO2 mixturewhich contains impurities

Separation of CO2, integrated with H2-purification. H2 is produced to be used as carbon-free fuel

A change in pressure

(range: 0-30 bar) drives the regeneration of the sorbent

CO2

Waste (N2)

Dryfeed

Adsorption Heating Cooling

t ime

Rinse PurgeSorbent regenerationis allowed for by recovered waste heat (up to 150°C)

H2 purification PSA plant, Linde North America• Classical absorption process with recycle between absorber

and desorber

• CO2 uptake capacity limited by solid formation (NH4HCO3)

• Solid handling section introduced

• Solid formation (NH4HCO3) exploited to make CO2 capture less energy intensive

Direct Air CaptureDAC

Vacuum-TemperatureSwing Adsorption (VTSA)Processes

CO2 separation from airrecovering waste heator exploiting renewable heat sources

Distributed captureTechnology

Production of pure CO2

stream for direct utilization

DAC units, Climeworks

AirAdsorption-based Processes development:Challenges

Characterization of new adsorbent materials and definition of optimal adsorbent

specifications

Optimization of process design for maximum efficiency

Technology scale-up

Characterization of multi-component competitiveadsorption, hysteresis and non-idealities

20

40

60

80

100

Co

ntr

ibu

tio

ns

to r

ou

nd

-tri

p

eff

icie

ncy

of

P2C

H4

[%]

Electricity input

Electricity output

Ele

ctro

lysi

s lo

sse

s

DA

C lo

sse

s

Fue

l syn

the

sis

loss

es

Fue

l co

nve

rs.

loss

es

Rate-based model development Model-based process design and development

Thermodynamics Trans Phenom & Kin Synthesis Optimization Integration

CO2 comp

Auxiliaries

Cooling

Chilling

Reboiler

CO2 desorber

Other

reboilers

Steam generation

Heat recovered from the

cement plant and

integrated in the CAP

Liquid Chilled Ammonia Process (L-CAP)

Controlled Solid Formation Chilled Ammonia Process (CSF-CAP)

Mineral carbonation in a nutshell

Recycling of concrete waste

RCA

Mineral Carbonation Mineral Carbonation

CO2 CO2

C- RCA

SandCaCO3

Accelerated

carbonation

Concrete recycling

Crushing

Iron removal

Classification

Iron

Decentralized concrete recycling

Kiln

Fuel

Clinker

1 Mt

0.84 MtCO2

MillCement0.55 MtCO2

0.29 MtCO2

Cement plant

Infrastructure

0.05 MtCO2

Additions

CaCO3 + SiO2

1.6 Mt

Air

Concrete plants

Gravel

Concrete

Sand Water

Decentralized concrete manufacturing

Centralized cement manufacturingConcrete fines

0.05 MtCO2

• Cement manufacturing is responsible for approx. 6% of the global CO2

emissions• Lack of foreseeable alternative for

cement and for its manufacturing process

• 2/3 of the CO2 stems from the raw material (limestone)

• Recycling of concrete waste can store CO2 and avoid the calcination of new limestone