Prof. Dr. techn. G. Scheffknecht

Institute of Combustion and Power Plant Technology

M. Hornberger, H. Dieter, G. Scheffknecht

The 6th High Temperature Solid Looping Cycles Network Meeting,

September 1st, 2015, Milan

Calcium Looping Post Combustion CO2 Capture:

A promising technology for emission free

cement production

2

Expertise in Lime based Fluidized Bed Processes

Fluidized Bed Processes

Calcium Looping (CaL)

Chemical Looping (CLC)

Oxy-fuel CFB

Sorption enhanced reforming (SER)

Oxy-fuel SER

Fuels

Biomass

Waste

Lignite / Coal

Measurement techniques

Sorbent Characterization (TGA)

Online gas analysis:

CO2, CO, O2, H2, CH4, SOx, NOx

Non-condensable HC: GC

Tar: wet chemical & online (FID)

H2S, HCl, NH3: wet chemical

200 kWth DFB Pilot

Facility20 kWth electrically heated

DFB System

5 kWth electrically heated

FB batch System

Calcium Looping – Post Combustion CCS

Flue

Gas

Air

Coal

ASU

O2

N2

CO2-lean

Flue Gas

CO2-rich Flue Gas

CO2 to Storage

CaCO3

CaO

Calciner

T = 900 °CCaCO3 + Heat CO2 + CaO

CO2

Conditioning

Make-up Limestone

Purge

Carbonator

T = 650 °CCO2 + CaO CaCO3 + Heat

CoalAir

Power Plant

G 1

Steam Generator

CaL Steam Generator

G 2

retrofitting to existing facilities

low CO2 separation cost

low efficiency penalty3

Calcium Looping – Post Combustion CCS

4

General conditions

Looping Ratio: 2 - 10

Make-up Ratio: < 0,1 - 0,4

Temperature

TCalciner: 850 - 1000 °C

TCarbonator: 600 - 700 °C

Flue gas

CO2: ~ 15 %

F

B C

aro

bn

ato

r

F

B C

alc

ine

r

CO2 lean

Flue Gas

Flue Gas

CO2 rich Gas

CaCO3

Fuel

O2

Steam Cycle

PurgeAsh

Air

Fuel

Steam Cycle

Calcium Looping – Pilot Plant (200 kWth)

Operation Conditions

Flue Gas Load: 170 - 230 kWth

Sorbent Looping Ratio: 3 - 13 molCaO/molCO2

Total Solid Inventory: 70 - 120 kg CaO/CaCO3

5

CaO

CaCO3

CO2-rich Gas

reci.

Flue Gas

CO2-lean

Flue Gas

O2 + reci.

Flue Gas

O2 + reci.

Flue Gas

O2 + reci.

Flue Gas

Flue

Gas

O2

Operational Results – Carbonator

6

500

600

700

800

900

1000

Tem

pe

ratu

re [

°C]

T Regenerator

T Carbonator

60

70

80

90

100

CO

2 C

aptu

re [

%]

ECO2

0

5

10

15

20

8:05 9:05 10:05 11:05 12:05 13:05

CO

2C

on

c. [

vol-

%]

yCO2, in

yCO2,out

Over 90% capture efficiency achieved over a wide range of operating conditions

Operational Results – Oxy-fuel Calcination

7

Operational Results – Oxy-fuel Calcination

8

High inlet oxygen concentrations

(> 50 vol.-%,dry) possible

lower recirculation rates for oxy-

CaL calcination (additional CO2

from calcination)

lower humidity of CaL flue gas

uniform isothermal conditions

Calcium Looping – Pilot Plant (200 kWth)

Carbonator

CO2 capture efficiency above 90 %

Calciner

CO2 outlet concentrations above 90 vol.-%,dry

Inlet O2 concentrations above 50 vol.-%,dry

Excess O2 outlet concentration below 3 vol.-% ,dry

Operation Conditions

Flue Gas Load: 170 - 230 kWth

Sorbent Looping Ratio: 3 - 13 molCaO/molCO2

Total Solid Inventory: 70 - 120 kg CaO/CaCO3

9

CaO

CaCO3

CO2-rich Gas

reci.

Flue Gas

CO2-lean

Flue Gas

O2 + reci.

Flue Gas

O2 + reci.

Flue Gas

O2 + reci.

Flue Gas

Flue

Gas

O2

Cement Plant – Clinker Production and Properties

10

Mill

Pre-

heater

Rotary Kiln

Pre-

calciner

Cooler

Fuel Preparation

Flue Gas

Fuel

Air

Clinker

Limestone

Marl /

ClayAdditive

Raw

Meal

clinker composition

CaO: 60 - 70 %

SiO2: 20 - 25 %

Al2O3: 2 - 6 %

Fe2O3: 0 - 6 %

structural change at 1400 °C (rotary kiln)

CaO + SiO2 (CaO)3 ∙ SiO2 & (CaO)2 ∙ SiO2

flue gas composition

high CO2 concentration ~ 30 %

Pre-

heater

Rotary Kiln

Pre-

calciner

Cooler

Fuel Preparation

Fuel

Air

Clinker

FB

Ca

rob

na

tor

FB

Ca

lcin

er

CO2 lean

Flue GasCO2 rich Gas

Flue Gas

CaCO3

Fuel

O2 CaO

Raw Meal

Marl / Clay

Additive

Cement Plant – CaL Integration

General conditions

Looping Ratio: 2 - 4

Make-up Ratio: > 1

Flue gas

CO2: 15 - 30 %

synergy effect between cement plant and CaL-process

11

Summary

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Calcium looping for power plant application demonstrated at pilot plant

scale

CO2 capture efficiency over 90 %

CO2 concentrations over 90 %

Feasibility for cement plant application will be investigated at pilot plant

scale

Effect of high CO2 flue gas concentration

Influence of make-up ratio, sorbent looping ratio

Optimal operation conditions

Thank you for your attention!

Acknowledgement

This project has received funding from the European Union's Horizon 2020

research and innovation programme under grant agreement no 641185

www.sintef.no/cemcap

Twitter: @CEMCAP_CO2

Disclaimer: The European Commission support for the production of this publication does not constitute endorsement of the contents which reflects the

views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein

Thank you for your interest!

Any Questions?

12

Contact:

Hornberger Matthias

Institute of Combustion and Power Plant Technology,

University of Stuttgart

matthias.hornberger@ifk.uni-stuttgart.de

http://www.ifk.uni-stuttgart.de