7th International Freiberg Conference7th International Freiberg Conferenceon IGCC & XtL Technologies

Evolution of tar compounds in raw gas p gfrom a pilot‐scale underground coal gasification (UCG) trialgasification (UCG) trial

Dr. Krzysztof Kapusta, Prof. Krzysztof Stańczyk, Dr. Piotr MocekCentral Mining Institute (GIG)Central Mining Institute (GIG)POLAND

Huhhot 9th June, 2015

Recent UCG projects in Central Mining Institute (GIG)

HUGEHUGE 2007 - 2010

Elaboration of coal gasification technology for a high efficiency production of fuels and electricityg y p y

2010 - 2015

HUGE2HUGE2 2011 - 2014

COGARCOGAR2013 - 2016

Funding sources:TOPS

2013 - 2016

gEU Research Fund for Coal and Steel

National Centre for Researchand Development (NCBR)

Coal2Gas2014 - 2017

and Development (NCBR)

EU 7th Framework Programme

Pilot-scale UCG installationSite selection

Coal Mine „Wieczorek”

3

UCG pilot plant „Wieczorek”Location of UCG gasifier

Coal seam No. 510Geological profile

O l i t tOverlying strata thickness: ~430 m

Coal seamCoal seamthickness: 5.5 m

UCG pilot plant „Wieczorek”Geometries of gasification channels

w skale płonnej

2,5 m

otwory badawcze

w węglu pokładuchodnik badawczy dla udostępnienia georeaktora

pokład 5015,5 m

połączone otwory badawczeo średnicy 200 mmwykonane w kształcie litery “V”w skale płonnej ok...20m

30 mchod

n ik

bada

wcz

y

hodn

ik b

adaw

czy

tyla

cyjn

y po

z.40

0 m

m

węgiel pokładu 501

c h

prze

kop

wen

t

UCG pilot plant „Wieczorek”Installation flow chart

Schemat ideowy instalacji pilotowej PZW Gas collection and purification

6

11

3

41213

1098714 109814

Supply

12

Supply

5Legenda

Underground sectionLegenda1. Separator smoły2. Zbiornik smoły3. Zbiornik ścieków4. Chłodnica5. Georeaktor6. Układ posadzki7. Zbiornik wody

8. Zbiornik i parownica azotu9. Zbiornik i parownica tlenu10. Sprężarka powietrza11. Separator wody12. Wentylator (sprężarka wodokrężna, sprężarka Roots'a)13. Komora spalania z palnikiem14. Pompa wody obiegowej

UCG pilot plant „Wieczorek”Underground galleries

UCG pilot plant „Wieczorek”Drilling of gasification channels

UCG pilot plant „Wieczorek”Surface UCG gas purification module

UCG pilot plant „Wieczorek”Coal characteristics

Moisture Wtr 7,00%t

Ash Ar 10,07%

T t l l h S r 0 92%Total sulphur Str 0,92%

Calorific value Qir 25 272 kJ/kg

Carbon Cta 66,00%

Volatiles Va 28 68%Volatiles Va 28,68%

Roga index RI 0,0

Pilot-scale UCG trialSummary results

Parameter Value

G ifi i Ai b Gasification agent Air, oxygen, carbon dioxide

Agent supply rate Nm3/h 600-650Agent supply rate, Nm /h 600-650

Experiment duration, days 56

Average gas production Nm3/h 800Average gas production, Nm3/h 800

Average gas composition, %:CO2 7.52H2CH4CO

141.516CO

N2

1661

Average gas heating value MJ/Nm3 3 50Average gas heating value, MJ/Nm 3.50

Total coal consumption, tons 250

Pilot-scale UCG trialGas composition vs. Time

UCG tar evolution studies

Gasification tar Classification system

Class Type Examples

1 GC undetectable tarspreasphaltenes, asphaltenes,

1 GC undetectable tarsheaviest tars (pitch)

2 Heterocyclic compounds. phenol, cresol, quinoline, pyridine

3 A ti t li ht h d btoluene, xylenes, ethylbenzene

3 Aromatic components - light hydrocarbons.toluene, xylenes, ethylbenzene (excluding benzene)

4Light polyaromatic hydrocarbons (2-3 rings PAHs).

naphthalene, indene, biphenyl, anthracenePAHs). anthracene

5Heavy polyaromatic hydrocarbons (4-rings PAHs).

fluoranthene, pyrene, crysene

6 GC detectable not identified compounds unknown6 GC detectable, not identified compounds unknown

Source: Patrick C.A., et al, The novel “OLGA” technology for complete tar removal from biomass producer gas Pyrolysisand Gasification of Biomass and Waste Expert Meeting 2002 Strasbourg Franceand Gasification of Biomass and Waste, Expert Meeting, 2002, Strasbourg, France

Tar compounds, sampling and analysis

Compound/group of compounds Sampling methodDetermination method

BTEX:Benzene, Toluene, Ethylbenzene,

Sampling on sorbent tube with activated carbon (SKC Anasorb CSC, 600 mg)

Gas chromatographywith FID detector (AGILENT 7890A)y ,

Xylenes (o-, m- p- isomers)( )

15 PAHs:Naphthalene (NaP), Acenaphthene (AcP), Fluorene (Flu), p ( ), p ( ), ( ),Phenanthrene (Phe), Anthracene (AnT), Fluoranthene (Fla), Pyrene (Pyr), Benzo(a)anthracene (BaA), Chrysene (Chr), Benzo(b)fluoranthene (BbF), Benzo(k)fluoranthene (BkF), Benzo(a)pyrene (BaP) Dibenzo(a h)anthracene (DBA)

Sampling on sorbent tube with polymer rasin (SKC XAD-2, 600 mg)

Gas chromatographywith MS detector (AGILENT 7890A)

Benzo(a)pyrene (BaP), Dibenzo(a,h)anthracene (DBA), Benzo(g,h,i)perylene (BghiP), Indeno(1,2,3-cd)pyrene(IND)

Phenols:Phenol (hydroxybenzene) o – Cresolm – Cresol

Sampling on sorbent tube with silica gel(SKC SilicaGel, 600 mg)

Gas chromatographywith FID detector (AGILENT 7890A)

m Cresolp – Cresol

(AGILENT 7890A)

UCG pilot plant „Wieczorek”Tar sampling point

Tar sampling valve

Raw UCG gasg

Evolution of tar compounds in UCG gasTar classes

2500

BTEX PAHsPh l

1500

2000on

, mg/

Nm3 Phenols

1000

Conc

entra

tio

500

C

0 200 400 600 800 1000 1200 1400

0

Time, h

Tar group Concentration, mg/Nm3mean min max

BTEX 1 428 1 455 6 2 303 4BTEX 1,428.1 455.6 2,303.4PAHs 477.7 59.6 1,633.2Phenols 87.7 12.4 205.2

Evolution of tar compounds in UCG gasBTEX

1600

1800

Benzene

1400

1600

Nm3

Toluene Ethylbenzene m,p-Xyleneo-Xylene

1000

1200

atio

n, m

g/N y

IntensiveDevelopment ofpyrolysis zone

600

800

Conc

entra

Intensivepyrolysis Thermal

decompositionCH3

200

400

C

0 200 400 600 800 1000 1200 1400

0

Time, h

Evolution of tar compounds in UCG gasAlkyl benzenes

100 EthylbenzeneDevelopment ofIntensive

80

100

/Nm

3

t y be e e m,p-Xylene o-Xylene

Th l d iti

ppyrolysis zonepyrolysis

60

80

atio

n, m

g/ Thermal decomposition(loss of alkyl group)

CH3

40

Conc

entra

20

C

0 200 400 600 800 1000 1200 14000

Time, h

Evolution of tar compounds in UCG gasPAHs (light)

500

NaphthaleneIntensive

400

/Nm

3

Acenaphthylene Fluorene PhenanthreneAnthracene

pyrolysis

300

atio

n, m

g/

Anthracene Fluoranthene Pyrene

Thermal decomposition

200

Conc

entra

decomposition

Development ofpyrolysis zone

100

C

0 200 400 600 800 1000 1200 1400

0

Time, h

Evolution of tar compounds in UCG gasPAHs (heavy)

60

50

g/Nm

3

Acenaphthene Benzo(a)anthracene ChryseneBenzo(b)fluoranthene

30

40

atio

n, m

g ( ) Benzo(k)fluoranthene Benzo(a)pyrene Indeno(1,2,3-cd)pyrene Dibenzo(a,h)anthracene

20

30

Conc

entra Benzo(g,h,i)perylene

10

C

0 200 400 600 800 1000 1200 1400

0

Time, h

Evolution of tar compounds in UCG gasPhenols

140

Ph l

100

120

Nm3

Phenol o-cresol m,p-cresol

80

100

atio

n, m

g/N OH

OH

40

60

Conc

entra CH3

20

40C

0 200 400 600 800 1000 1200 1400

0

Time, h

Statistical analysisPrincipal Component Analysis (PCA)

1.0

benzen

BTEX

fenantrenfluoranten

PAHs0.5

benzen

BTEX

fenantrenfluoranten

PAHs

High temperature formation

acenaftylen

naphthaleneenaften fluorentracen

42%

acenaftylen

naphthaleneacenaften fluorenantracen

etylobenzen

0.0

PC2

: 29.

4

etylobenzen Compounds

toluen

etylobenzen

m,p-ksyleno-ksylen

h l

o-cresol-0.5

toluen

etylobenzen

m,p-ksyleno-ksylen

h l

o-cresol

vulnerable to decomposition at hig temperature,p y

phenolm, p-cresol

Total phenols

-1.0

,p yphenol

m, p-cresolTotal phenols

-1.0 -0.5 0.0 0.5 1.0

PC1 : 59.93%

Conclusions

Concentrations of tar compounds in the raw UCG gas are strongly Concentrations of tar compounds in the raw UCG gas are stronglydependent on the stage of the gasification process and they reflectthermodynamic conditions inside the underground reactor – the early stageof UCG was characterized by highest concentrations of all tar classes underof UCG was characterized by highest concentrations of all tar classes understudy

BTEX was the most abundant group of tar compounds in raw UCG gas, andbenzene was found to be a dominant compound (~75%)

PAHs were identified as the second most abundant class of tars in UCG gasand naphthalene contributed to about 30% of total PAHs

Relatively smallest concentrations were observed for phenolic compounds.

Thank you yfor your attention