Effect of oxy-fuel combustion with steam and biomass

National Coal Institute (INCAR-CSIC)

www.incar.csic.es

J. Riaza, L. Álvarez, M.V. Gil, C. Pevida, J.J. Pis, F. Rubiera

[email protected]

Effect of oxy-fuel combustion with steam and biomass addition on coal burnout in an entrained flow reactor

Energy Processes and Emission Reduction Group


Figure by courtesy of Vattenfall


To evaluate the effect of:

Water vapour recirculation in the oxyfuel combustion (10 and 20 vol. %).

Biomass blending with the coal under oxyfuel conditions in an entrained flow reactor (10 and 20 w.%).

Burnout NO

Emissions

N2 / O2 / CO2 / H2O

Fuel

Exhaust gases

Entrained Flow Reactor


Characteristics

Entrained Flow Reactor

Cyclone

Filter

Injector

Flow

straighteners

Heating resistance

Pre-heater

Insulator

Sampling probe

Cooling water

Suction pump

Feeding system

N2 / O2 / CO2 / H2O Cooling

air

Fuel

Quenching gas

O2 N2O

CO2 CO

NO SO2

Gas analysers

Feeding system

Wall temperature: 1273 K

Reactor zone length: 1.4 m

Reactor diameter: 40 mm

Residence time 2.5 sec

Continuous coal feeding system

Gas analysers: O2, CO2, NOX, SO2, CO


db: dry basis; daf: dry and ash free bases; *Calculated by difference.

Ash V.M. F.C.+ C H N S O+

HV semi-anthracite 10.7 9.2 80.1 91.7 3.5 1.9 1.6 1.3 31.8

SABhigh-volatile

bituminous coal15.0 29.9 55.1 81.5 5.0 2.1 0.9 10.5 27.8

BAhigh-volatile

bituminous coal6.9 33.9 59.2 88.4 5.5 1.9 1.1 3.0 33.1

OR olive residue 7.6 71.9 20.5 54.3 6.6 1.9 0.2 37.0 19.9

Sample Rank/OriginProximate Analysis

(wt%, db)

Ultimate Analysis

(wt%, daf)

HHV

(MJ/kg,db)

75-150 µm


BIOMASS ADDITION

+ 10 % + 20 % WEIGHT

WATER VAPOUR ADDITION


92.5 93.9

95.2

90.2 92.7 93.0 93.9

95.0 95.8 94.7 95.7

97.8

50

60

70

80

90

100

SAB 90%SAB-10%OR 80%SAB-20%OR

Bu

rno

ut

(%)

79%N2-21%O2 79%CO2-21%O2

70%CO2-30%O2 65%CO2-35%O2


79.4 80.4

83.0

92.5 93.9

95,2

77.2

79.7 81.0

90.2

92.7 93.0

80.7

83.5

86.1

93.9 95.0

95.8

84.2 83.5 85.5

94.7 95.7

97.8

50

60

70

80

90

100

HV 90%HV-10%OR 80%HV-20%OR SAB 90%SAB-10%OR 80%SAB-20%OR

Bu

rno

ut

(%)

79%N2-21%O2 79%CO2-21%O2 70%CO2-30%O2 65%CO2-35%O2


N2 / O2 / CO2

Fuel

NO Emissions 21 % O2 - 79% N2

21 % O2- 79% CO2 30 % O2- 70% CO2 35 % O2- 65% CO2

Exhaust gases


6.3

5.2

3.6

5.0

4.0

2.2

5.1

4.2

2.4

5.2

3.9

2.6

0

1

2

3

4

5

6

7

SAB 90%SAB-10%OR 80%SAB-20%OR

mg

NO

/ g

bu

rne

d f

ue

l

79%N2-21%O2 79%CO2-21%O2

70%CO2-30%O2 65%CO2-35%O2


Sample N

HV 1.9

SAB 2.1

OR 1.99,7

8,8

6,6 6,3

5,2

3,6

6,7 6,5

6,1

5,0

4,0

2,2

6,9 7,1

6,6

5,1

4,2

2,4

7,4

6,5 6,5

5,2

3,9

2,6

0,00

2,00

4,00

6,00

8,00

10,00

HV 90% HV-10% OR 80% HV-20% OR SAB 90%SAB+10%OR 80%SAB+20%OR

mg

NO

/ g

bu

rne

d f

ue

l

79%N2-21%O2 79%CO2-21%O2

70%CO2-30%O2 65%CO2-35%O2

NH3

HCN

NO


BIOMASS ADDITION

+ 10 % + 20 % WEIGHT

WATER VAPOUR ADDITION

Dry recycle

0% H2O 10% H2O 20% H2O

21% O2 - 79% N2 21% O2 - 69% N2 - 10% H2O 21% O2 - 59% N2 - 20% H2O

21% O2 - 79% CO2 21% O2 - 69% CO2 - 10% H2O 21% O2 - 59% CO2 - 20% H2O

30% O2 - 70% CO2 30% O2 - 60% CO2 - 10% H2O 30% O2 - 50% CO2 - 20% H2O

35% O2 - 65% CO2 35% O2 - 55% CO2 - 10% H2O 35% O2 - 45% CO2 - 20% H2O

Wet recycle


50

60

70

80

90

100

21%O2-79%N2 21%O2-79%CO2 30%O2-70%CO2 35%O2-65%CO2

Bu

rno

ut

(%)

HV

HV+ 10%H2O

HV+ 20%H2O

BA

BA+ 10%H2O

BA+ 20%H2O


9,7

6,7 6,9

7,4 7,7

5,9 6,3

6,8 6,7

5,0 5,5

6,5 6,9

6,0 6,4

6,6

6,1

4,8

5,6 5,2

0,00

2,00

4,00

6,00

8,00

10,00

79%N2-21%O2 79%CO2-21%O2 70%CO2-30%O2 65%CO2-35%O2

mg

NO

/ g

bu

rne

d f

ue

l

HV

HV+5%H2O

HV+10%H2O

HV+20%H2O

BA

BA+10%H2O

BA+20%H2O


• Replacing N2 by CO2 caused a decrease in the burnout values. When the O2 concentration was increased to 30% the burnout value was higher than in air conditions.

• A increase in the burnout value was observed after the addition of biomass.

• The emissions of NO during oxy-fuel combustion were lower than under air. However, they remained similar under all the oxy-fuel atmospheres with increasing O2 concentrations.

• Emissions of NO were significantly reduced by the addition of biomass to the bituminous coal, although this effect was less noticeable in the case of the semianthracite.

• No significant effect was observed in the burnout after the addition of steam.

• In general the presence of steam reduce the emissions of NO

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Thanks for your attention!


Acknowledgements CSIC (Project PIE 201080E09). J.R. acknowledges funding from the Government of the Principado de Asturias. L.A and M.V.G. acknowledge funding from the CSIC JAE-Pre and CSIC JAE-Doc programs, respectively, co-financed by

the European Social Fund.

Effect of oxy-fuel combustion with steam and biomass addition on coal burnout in an entrained flow reactor

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Effect of oxy-fuel combustion with steam and biomass