evaluation of an improved dual circulating fluidized...

Institute of Chemical Engineering

Zero Emission Technologies

Evaluation of an improved dual circulating fluidized

bed reactor design for chemical looping combustion

Karl Mayer, Stefan Penthor, Ellen Schanz, Michael Stollhof, Hermann Hofbauer

6th High Temperature Solid Looping Network Meeting

Milan, September 1-2, 2015

Karl MayerMilan, September 1-2, 2015



Outlook

2

• Introduction

• Data used for the new design

• The new pilot plant

• Results of benchmarking against the old reactor




Introduction

3

>1000 h of CLC operation in a 120kW pilot plant with different oxygen

carrier materials

- performance of each material was different

- some trends were the same for all materials

- the reactor system had a potential for further optimization




Introduction: Reference numbers

4

in,FR,CHinFR,

exh,FR,CHexhFR,

CH

4

4

4yn

yn1X

reactor fuel to carbon total

exhaust reactor fuel in CO2

CO 2Carbon dioxide yield:

Methane conversion:

Oxygen carrier to fuel ratio: 2

2

accessible O from oxygen carrier=

O demand fuel




Outlook

5

• Introduction







Data used for the new design:Fe and Cu based oxygen carriers

6

0 1 2 360

65

70

75

80

CH

4 c

on

ve

rsio

n, C

O2 y

ield

[%

]

[-]

XCH4

YCO2

1 2 3 4 5 630

40

50

60

CH

4 c

on

ve

rsio

n, C

O2 y

ield

[%

]

[-]

XCH4

YCO2

Mayer K et al. The different demands of oxygen carriers on the reactor system of a CLC plant – Results of oxygen carrier

testing in a 120 kWth pilot plant. Appl Energy (2015), http://dx.doi.org/10.1016/j.apenergy.2015.07.053

Fe17 Cu14




Data used for the new design:Fe and Cu based oxygen carriers

7

100 150 200 250 30050

60

70

80

90

CH

4 c

on

ve

rsio

n, C

O2 y

ield

[%

]

Specific FR inventory [kg/MW]

XCH4

YCO2

Fe17 Cu14

100 200 300 40030

40

50

60

70

XCH4

Fe17large

YCO2

Fe17large

XCH4

Fe17small

YCO2

Fe17small

CH

4 c

on

ve

rsio

n, C

O2 y

ield

[%

]







Data used for the new design:Clou oxygen carriers

8

C14 C28

0 10 20 30 4070

80

90

100

CH

4 c

on

ve

rsio

n, C

O2 y

ield

[%

]

[-]

XCH4

YCO2

0 10 20 30 4070

80

90

100

CH

4 c

on

ve

rsio

n, C

O2 y

ield

[%

]

[-]

XCH4

YCO2






Data used for the new design:Clou oxygen carriers

9

0 100 200 300 40070

80

90

100

XCH4

YCO2

CH

4 c

on

ve

rsio

n, C

O2 y

ield

[%

]


0 100 200 300 40070

80

90

100

XCH4

YCO2

CH

4 c

on

ve

rsio

n, C

O2 y

ield

[%

]


C14 C28






Outlook

10

• Introduction







Old vs. New Design: Specifications

11

unit old design new design

AR FR AR FRlow FRup

reactor diameter mm 150 159.3 129.7 179.5 102.3

reactor height m 4.1 3 4.03 0.75 3.05

inlet gas flow Nm³/h 140 12 140 12

outlet gas flow Nm³/h 114 36 114 36

temperature °C 940 850 950 950

archimedes number - 7.55 9.13 6.9 6.78

superficial velocity m/s 7.3 2.1 9.8 1.8 5.5

U/Umf - 1280 315 267 1876 975

fuel power (n.g.) kW 120 120

air/fuel ratio - 1.2 1.2




Old vs. New Design: Reactors

12

fue

lre

act

or

air

rea

cto

r

inte

rna

l lo

op

se

al

up

pe

r lo

op

se

al

lo w er loop se a lstea m

stea m

stea m

fuelprim.

a i r

se c.

a i r

a ir rea ctoro ff gas fu e l rea ctor

o ff gas




Old vs. New Design: Loop Seal

13

AR

do

wn

co

me

r

AR

do

wn

co

me

r

to FRto FR

old new

we

ir h

eig

ht

we

ir h

eig

ht




Outlook

14

• Introduction







Oxygen carrier used for benchmark campaign

15

Mixture of 60wt.% C14 and 40wt.% C28

C14 C28

Active metal oxide [-] CaMn0.9Mg0.1O3-δ CaMn0.775Mg0.1Ti0.125O3-δ

Active metal oxide

contentwt% - -

Particle size [µm] 130 160

Bulk density [kg/m³] 1540 1220




Results: Gas leakage between reactors

16

0

0.25

0.5

0.75

1

0 20 40 60 80 100 120

leak

age

VN

2[N

m³/

h]

Gs [kg/m²s]

C28

Cu Carrier

C14

Fe17

Ni Carrier

New Design




Results: Specific FR - Inventory

17

75

80

85

90

95

100

0 100 200 300 400

CH

4convers

ion,

CO

2yie

ld [

%]

Specific FR inventory[kg/MW]

XCH₄

YCO₂

XCH₄,C14

YCO₂,C14

XCH4,C28

YCO2,C28

XCH4

YCO2

XCH4

YCO2

XCH4

YCO2

new design

C14

C28




Results: OC / fuel ratio

18

70

75

80

85

90

95

100

5 10 15 20 25 30 35

CH

4convers

ion,

CO

2yie

ld [

%]

[-]

XCH₄

YCO₂

XCH₄,C14

YCO₂,C14

XCH4,C28

YCO2,C28

XCH4

YCO2

XCH4

YCO2

XCH4

YCO2

new design

C14

C28




Thank you

19

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