Calcium looping process for low CO emission cement and power · 2013. 7. 25. · 2/15 M.Romano –High Temperature Solid Looping Cycles,15-17 Sept. 2010 Cement industry is the second

Calcium looping process for low CO2 emission cement

and power

Matteo C. Romano, Politecnico di Milano – Energy Department

2nd Network Meeting - High Temperature Solid Looping Cycles

15-17th September 2010, Alkmaar & Petten

2/15

M.Romano – High Temperature Solid Looping Cycles,15-17 Sept. 2010

Cement industry is the second largest CO2 emitter from large

stationary plants.

CO2 emissions from the cement industry

Centrali

elettriche

78%

Cementifici

7%

Altre fonti

1%

Industria

petrolchimica

3%

Produzione di

ferro e acciaio

5%

Raffinerie

6%

Power

plants

78%

Cement plants

7%

Refineries

6%

Iron and steel

industry

5%

Petrochemical

industryOthers

1%

3/15


ReactionsFlow rate

[kg/kgclinker]

ΔHr, 298,15K

[kJ/kgclinker]

CaCO3 CaO + CO2 1.190 2118.43

3CaO + SiO2 C3S 0.6125 -330.63

2CaO + SiO2 C2S 0.1649 -129.47

3CaO + Al2O3 C3A 0.0866 1.85

4CaO + Al2O3 + Fe2O3 C4AF 0.0845 -9.97

Clinker: composition and reactions

Clinker composition:

Alite phase (Tricalcium Silicate): 3CaO•SiO2 (C3S) ~ 60-65% wt.

Belite phase (Dicalcium Slicate): 2CaO•SiO2 (C2S) ~ 15-18% wt.

Aluminate phase: 3CaO•Al2O3 (C3A) ~ 8-10% wt.

Ferritic phase: 4CaO•Al2O3•Fe2O3 (C4AF) ~ 8-10% wt.

About 60% of CO2 emissions come from CaCO3, the remaining from fuel combustion

4/15


Calusco (Italcementi): a state-of-the-art plant

Precalcier and

raw meal preheating

Rotating kiln:

clinker production

Clinker cooling and

air preheating

5/15


enthalpy [kcal/kg ck]

INLET FLOWSFlow rate

[kg/kg ck]

T

[°C]GS code

REPORT

Calusco

total fuel 0,091 743,4 743,3sens heat fuel 0,091 40 1,10 1,10sens heat raw meal 1,609 65 23,8 21,3clinker cooling air 2,347 7 3,96 3,90primary air main burner 0,036 42 0,37 0,40transport air main burner 0,022 55 0,29 0,30primary air aux. burner 0,131 40 1,26 1,20transport air aux. burner 0,022 55 0,29 0,20false air 0,015 7 0,02 0,04heat shield cooling air 0,040 10 0,10 0,10water spraying cooler 0,009 10 0,09 0,10

Modeling & simulation carried out with the in-house GS code, used for the

modeling of power plants and chemical processes in a number of publications

and contracts

Italcementi Calusco plant modeling

6/15


Italcementi Calusco plant modeling

enthalpy [kcal/kg ck]

OUTLET FLOWSFlow rate

[kg/kg ck]

T

[°C]GS code

REPORT

Calusco

Heat of formation 422,3 423

gas at preheater outlet 1,844 315 141,7 145

clinker from the cooler 1 131,1 27,4 26,2

excess air from the cooler 1,292 330 104,7 104,5

water vapor from cooler 0,009 330 1,37 1,4

water evaporation 0,009 330 5,38 5,4

hot air to coal mill 0,106 603 16,1 16

evaporation of res. moist 0,004 65 1,9

dust with preheater off gas 0,070 315 5,07 5

kiln shell+kiln

loss+ventilation 33,0 32,8

preheater loss 24,0 24

cooler loss 0,60 0,6

Modeling & simulation carried out with the in-house GS code, used for the

modeling of power plants and chemical processes in a number of publications

and contracts

7/15


clinker

Power and cement plant synergy

Boiler Carbonator

CaO+CO2 CaCO3

Calciner

CaCO3 CaO+CO2

coal air

Flue

gas

CaO

CaCO3

coal O2 CaCO3

Make-up

Low-CO2

flue gas

CO2 to

storage

Ca-LOOPING POWER PLANT CEMENT PLANT

Kilnblow-off CaO

coal

airAdditional

feedstock

Low-CO2

flue gas

8/15


Precalciner burner is shut down and fuel flow to the main kiln burner is

calculated to obtain the same temperature profile of the reference case:

• Overall fuel consumption: -65%

• Overall CO2 emissions: -85%

Using CaO as cement plant feedstock

Is it really possible to replace all the limestone with lime from

a Ca-looping power plant?

Is it so simple?

9/15


Blow-down stream from Ca-looping power plant also contains coal ash

and CaSO4.

a limiting specie can exist: in that case, if all CaCO3 were

replaced with CaO from power plant, clinker would be too rich

of this limiting specie.

One case was calculated: blow-down composition obtained from a

model of a Ca-looping power plant with oxy-fuel calciner.

Coal composition: 0.85% S, 12.7% Ash (2/3SiO2, 1/3Al2O3);

LHV = 24.6 MJ/kg

Ca-looping power plant blow-down as feedstock

10/15


limestone

coal

LP preheaters - heat from

CO2 and air IC compressors

34

2

8

limestone

coal

13

blow off

carbonator

calciner

e.m.

ASU12

N2

5

6 7

9

10

11

15

16e.m.

ECO+EVA+SH

14

17

18

19 20

21

~

1

HP preheaters22

FF

b-d

adapted from Romano: “Coal fired power plant with calcium oxide carbonation for

post-combustion CO2 capture”; Energy Procedia, 1, 1099-1106, 2009.

Ca-looping power plant layout

11/15


Calculated case:

• a blow-down fraction of 1% was assumed from the looping

Resulting blow-down

composition

%wt.

CaO 68.6

CaSO4 6.7

SiO2 16.5

Al2O3 8.2

100.0

Cement plant input [kgi/kgclinker]

From power plant 0.643

CaCO3 0.467

Fe2O3 0.029

SiO2 0.123

Ca-looping power plant blow-down as feedstock

about 25% of coal ash in the blow-down,

Al2O3 is the limiting specie

the amount of the other species to be

added from other sources can be

consequently obtained

12/15


No

capture

Pure CaO

feed

Power plant

feed

CEMENT PLANT

CO2 emissions [g/kgclk] 836.6 128.0 388.6

from CaCO3 calcinat. [g/kgclk] 549.5 - 221.2

from fuel [g/kgclk] 293.7 128.0 167.4

Fuel consumption [kg/kgclinker] 0.09 0.031 0.052

Precalciner [kg/kgclinker] 0.054 - 0.018

Kiln [kg/kgclinker] 0.036 0.031 0.034

CO2 emission variation [%] -84.8 -53.9

Fuel consumption variation [%] -65.7 -42.9

Results

13/15


• The performance of the integrated cement and Ca-looping power plants

will strongly depend on:

• coal characteristics: ash content, ash composition, sulfur content,

heating value

• Ca-looping power plant design parameters: blow-down fraction and

CaO excess in carbonator (or F0/FCO2 and FR/FCO2)

• Cement and power plant relative size also depends on the same

parameters:

• the larger the blow-down, the higher the CaO exported per kWh

produced, the smaller the power plant needed to feed a cement plant

of a given size.

• An extensive sensitivity analysis is hence needed to optimize the

integrated plant and optimum working conditions, which are coal-

dependent and can be sensibly different from those of a stand alone Ca-

looping power plant.

Some considerations and conclusions

14/15


• Reactivity of the material from the Ca-looping plant in clinker production

must be verified.

• If there is no surprise from reactivity analysis, the potentiality of this cement

& power production plant in reducing emissions from cement sector at low

cost is huge:

• no modification to the cooking process

• possibility of retrofitting, maybe with some modifications to the solids

preheater

• reduced fuel consumption in the cement plant

• This option give a further chance to Ca-looping over competitive

technologies, since it is the only electricity + CaO cogeneration technology.

• A logistical problem exist: cement and power plants should be built near.

Possible problems related to space availability and public acceptance.

Some considerations and conclusions

15/15


Thank you30 sec. commercial:

Latest publications of our research group on high temperature solid looping cycles:

• Romano, Lozza: “Long-term coal gasification-based power plants with near-zero

emissions. Part A: Zecomix cycle”; Int J Greenh Gas Con, 4, 459-468; 2010.

• Romano, Lozza: “Long-term coal gasification-based power plants with near-zero

emissions. Part B: Zecomag and oxy-fuel IGCC cycles”; Int J Greenh Gas Con,

4, 469-477; 2010.

• Romano, Cassotti, Chiesa, Meyer, Mastin: “Application of the Sorption Enhanced

– Steam Methane Reforming process in combined cycle-based power plants”.

Oral presentation on Monday at GHGT-10.

Ca-looping chance is concrete…

Documents

Calcium looping process for low CO emission cement and power · 2013. 7. 25. · 2/15 M.Romano –High Temperature Solid Looping Cycles,15-17 Sept. 2010 Cement industry is the second