A CONCEPT OF POLISH LIGNITE INA CONCEPT OF POLISH LIGNITE IN--SITU SITU CONVERSION USING HYBRID GASIFICATION CONVERSION USING HYBRID GASIFICATION

METHODMETHOD

6th International Freiberg Conference on IGCC & XtL Technologies19 - 22 May 2014, Dresden

Magdalena Król, Agnieszka Szubert

KGHM CUPRUM R&D CentreKGHM CUPRUM R&D Centre� head office located in Wrocław

� was established in 1967

� is fully owned by KGHM Polska Miedź SA

� has the status of a research and development centre

� employs 150 people, of which 60% are researchers

� main fields of CUPRUM activity are

� exploration ( geology & hydrogeology)� exploration ( geology & hydrogeology)

� mining (design, exploitation technologies, etc.)

� ore processing

� environmental protection

� technologies for extractive industry

BackgroundBackground of of researchresearchBackgroundBackground of of researchresearch� From few years Cuprum activities related to underground thermal lignite

gasification are carried out by Department of New Energy Technologies, created in2008

� Since then, several polish lignite deposits/seams were considered as potential candidates for thiskind of treatment and few research works were done on it (mainly for KGHM PM)

� From 2009 Cuprum is involved in the tasks concerning UCG in the national strategic project entitled"Development of coal gasification technology for highly efficient production of fuels and electricity”funded by polish National Centre for Research and Development

� We also conduct conceptual work for polish mining industry (PGE GIEK Turów , PGE Gubin)concerning both above and underground thermal lignite gasification

� We found out about an emerging method of lignite decomposition into valuable� We found out about an emerging method of lignite decomposition into valuableproducts with using microorganisms ( number of information very limited )

� 2011: (internal funds) a research study consisting in analysing possibility of its potential applicationfor a selected polish lignite deposit (Siedlimowice, Lowe Silesia region): results were encouraging(assuming reaction efficiency adapted from literature): no possibility of taking lignite samples fromthe seam

� 2013: we started a research project on the biogasification method in order to find out about itseffectiveness, to determine main process parameters and criteria of its potential application

No. 2011/03/D/ST8/04467 – Research into the process of biological decomposition of ligniteto methane to determine the possibilities of application in the small, off-balance deposits- funded by polish National Centre of Science

Based on our previous and current activities, an idea ofhybrid gasification with complementary use of thermaland biological gasification appears …

Underground thermal Underground thermal gasificationgasification of of lignitelignite –– alreadyalready knownknown??Underground thermal Underground thermal gasificationgasification of of lignitelignite –– alreadyalready knownknown??

Underground gasification of lignite is not a single chain reaction of carbon matrix

� lignite conversion occurs directly in the seam,

� no preparation of the raw material for the process (grinding, predrying, selection, etc.)

� in gasification channel parallel processes are observed:� physical processes- drying, degassing, material shrinkage and crushing, etc.� thermo-chemical decomposition reactions of raw coal material - combustion, gasification, and low

temperature carbonization/pyrolysis

� main process reactions concerning carbon matrix:

C+ O2= CO2 (1)C+ O2= CO2 (1)

C+ ½ O2= CO (2)

C+ CO2=2 CO (3, Boudouard reaction)

C+ H2O= CO+ H2 (4)

C + 2H2= CH4 (5, methane synthesis)

Cross-section of lignite block during gasification. Heat from combustion zone results in gradual lignite block decomposition through drying, pyrolysis and gasification processes ( Król M., 2010]

in situ thermal gasification demands site-specific solutions

Country Owner Place Start date Expected product

Uzbekistan Linc Energy

(Yerostigaz)

*Angren since 1961 –to today Heat and

electricity

Australia Linc Energy Chinchilla 1999 –2002

2010-2012

Liquid fuels

GTL (F-T)

Australia Carbon Energy Bloodwood

Creek

2008 – 2012 Electricity

China ENN Wulanchabu 2007 – to today Electricity/ SNG

Underground thermal Underground thermal gasificationgasification of of lignitelignite –– alreadyalready knownknown??Underground thermal Underground thermal gasificationgasification of of lignitelignite –– alreadyalready knownknown??

*commercial UCG, the facility has consistently produced one million cubic metres of UCG syngas per day

Chinchilla [photo: NTE, KGHM CUPRUM] Wulanchabu [photo: NTE, KGHM CUPRUM]

BiogasificationBiogasification: : biochemicalbiochemical//enzymaticenzymatic reactionreaction of of degradationdegradation of of complexcomplex lignitelignite organicorganic mattermatter intointo biogasbiogas (CH(CH44 + CO+ CO22))

BiogasificationBiogasification: : biochemicalbiochemical//enzymaticenzymatic reactionreaction of of degradationdegradation of of complexcomplex lignitelignite organicorganic mattermatter intointo biogasbiogas (CH(CH44 + CO+ CO22))

1.1. Hydrolysis:Hydrolysis:

2.2. Fermentation:Fermentation:

3.3. AcetogenesisAcetogenesis::

Lignite organic matter: complex organic

compounds

Soluble organic acids(long chain) and otherbyproducts, H2, CO2

Soluble fatty acids Volatile fatty acids (VTA)

2232223 264)( COHCOOCHOHCOOCHCH ++→+ −−

+− ++→+ HOHCOOCHHCO 2322 252

- Microorganisms producing H2:

- Microorganisms using H2 (producing additional amounts of acetate):

4.4. MetMethhanogenesisanogenesis::

++→+ HOHCOOCHHCO 2322 252

- Microorganisms degrading acetate and CO2:−− +→+ 3423 HCOCHOHCOOCH molkJG /31−=∆ o

OHCHHCO 2422 24 +→+ 4/135 molCHkJG −=∆ o

IMPORTANT: Nutrients addition (depending on lignite characteristics) and other stimulating components (solvents, surfactants) - to improve cells growth and activity and the reaction start-up.

As any other in situ process, biogasificationdemands site-specific

strategies

TheThe general general conceptconcept of of biogasificationbiogasification installationinstallation: (Szubert A., : (Szubert A., Nowak J., Grotowski A., 2011)Nowak J., Grotowski A., 2011)

TheThe general general conceptconcept of of biogasificationbiogasification installationinstallation: (Szubert A., : (Szubert A., Nowak J., Grotowski A., 2011)Nowak J., Grotowski A., 2011)

�� Unit for large biomass culture (mobile unit) Unit for large biomass culture (mobile unit) andand/or/or nutrient preparation (A)nutrient preparation (A)�� Module of Module of seamseam preparation preparation (drilling, facilities installation, slotting if needed) (B)(drilling, facilities installation, slotting if needed) (B)�� Nutrient (and microbes) injection unit and seam waters pumping out : pumps system and 1Nutrient (and microbes) injection unit and seam waters pumping out : pumps system and 1--2 retention 2 retention

pondsponds�� Process Process parameters and environmental protection control parameters and environmental protection control systemsystem�� Unit of biogas takeUnit of biogas take--off off �� Unit for gas purification, retention and transmission (C).Unit for gas purification, retention and transmission (C).

Lignite deposits in Poland Lignite deposits in Poland Lignite deposits in Poland Lignite deposits in Poland

� Poland is one of lignite-rich countries with huge prospective resources of lignite estimated at over 140 mld Mg and 26.1 mld Mg of reserves

� 10 lignite deposits with continuous exploitation

� 72 explored but for different reasons unexploited deposits

� proven off-balance lignite reserves in Poland -3.5 mld tones

� the highest concentration of lignite deposits occurs in the south-west Poland (in the voivodeships Lower Silesia, Lubusz andOpole)- 36 deposits, including 1 with open pit exploitation

Balance criteria of lignite deposit defined for exploitation by open pit method in Poland (PIG-PIB):

Parameter Value [unit]

Maximum deepness of deposit 350 [m]

Minimum thickness of lignite in the seam 3 [m]

Maximum ratio of overburden to deposit thickness 12 [--]

Minimum weighted average calorific value of lignite in the seam * 6.5 [MJ/kg]

Maximum weighted average total sulphur content in the lignite* 2 [wt.%]

* maeasured in raw lignite with with interlayers, humidity 50%

[source: Ciuk E., Piwocki M., 1999]

Lignite deposits categories No. ofdeposits

Geological reserves [mln Mg] Commercialreserves [mln Mg]balance off-balance

total reserves 90 22 583.83 3 547.64 1 219.12

including exploited lignite deposits

1. deposits with opened mines 10 1 585.09 87.06 1 219.12

1. deposits with

periodic exploitation2 5.67 21.74 0.76

Ʃ 12 1 590.76 108.80 1 219.12

including unexploited lignite deposits1. deposits explored in

details30 4 043.01 786.09 -

1. preliminary explored 42 16 940.79 2 648.48 -

[source: „Bilans zasobów złóż kopalin w Polsce” ,Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy , 2013]

Lignite deposits in Poland Lignite deposits in Poland Lignite deposits in Poland Lignite deposits in Poland

1. preliminary explored

deposits42 16 940.79 2 648.48 -

Ʃ 72 20 983.80 3434.57 -including lignite deposits in which exploitation has been stopped

Ʃ 6 9.28 4.27 -

In brief- lignite deposit characteristics in the context of in-situ gasification:� law rank coals with average LHV 8-12 MJ/kg

� usually horizontal deposition of seams in with glacial deformations and faults

� surrounded by clays, silts, and sands with different grain size

� in addition, the permeability parameters of geological formations occurring around lignite seams determine, that in most cases there is no possibility for large scale in-situ gasification

� is expected that, small lignite deposits have a potential to UCG application

General General criteriacriteria of of lignitelignite seamsseams evaluationevaluation for thermal and for thermal and biologicalbiological inin--situsitu gasificationgasification methodsmethods applicationapplication

InIn--situsitu technology technology applicationapplication –– general general conditionsconditions /1 /1 InIn--situsitu technology technology applicationapplication –– general general conditionsconditions /1 /1

Criteria Thermal Biological

Reserves of lignite deposit

It is proven that this technology may be economically sufficient in thin seams <10m

Small resources - few mln m3 of lignite

Lignite rank and quality Higher - better Lower-better

Lignite seam depth >100m Below aquifer, depending on isolation Economic aspects

Lignite seam thickness 2-10m 2-10 m (assumption)

Lignite seam isolation Preferred: min thickness of isolation higher than thickness of seam permeability of surrounding rocks < 10-8m/s

Permeability of surrounding rocks < 10-8m/s (clays-like rocks preferred)

permeability of surrounding rocks < 10-8m/s

Lignite seam permeability

Increase during the process (water evacuationfrom pores, cracking)

Minimum 1-2 x 10-6 cm/s (1 -2 Da) – if too low, fracking needed

Effective porosity and pores diameters

Influence on process kinetics iIf too low (or limited to macropores flow) fracking needed: bacteria cells diameter: 0,2-6,0 µm, surface limited reaction

Tectonics of the rock mass

Discontinuity of geological layers may impact of gas escapes and uncontrolled flooding of gasifier

Discontinuity of geological layers may result inuncontrolled migration of microorganisms and biogas losses.

Location –environmental aspects

Far enough from populated areas

InIn--situsitu technology technology applicationapplication –– lignitelignite seamseam /2/2InIn--situsitu technology technology applicationapplication –– lignitelignite seamseam /2/2

Criteria Thermal Biological

Water presence/humidity lower- better Typical lignites water content – sufficient for developing and maintaining bacteria activity. tributaries to the coal seam: nutrients dilution

Sulphur presence Lower - better Lower - better

Calorific value Higher-better Indirectly lower- betterDepends on carbon matrix structure, usually calorific value is lower in younger coals

Organic matter content Higher-better Less complex organic compounds preferred

Ash content Mineral matter take part in gasification reaction as catalytic agent, but if its too high may influence on process stability,

Not important if its components not influence microbial activity.

Ambient temperature No influence > 20 °C (optimum: ~ 33-35 °C)

pH 3.0-9.2 (optimum: ~ 7,0)

salinity 1 mM – 3M (Na+) (recent study: 47 mM –1.8 M Na+)

SIEDLIMOWICE DEPOSITSIEDLIMOWICE DEPOSITSIEDLIMOWICE DEPOSITSIEDLIMOWICE DEPOSITParameter Thermal Biological

Reserves of lignite deposit- balance resources – 1791 th. Mg + +

Lignite rank and quality: 6.3 MJ/kg, ash cont. 40 wt.% - +

Lignite seam depth 17 m bgl - - (ground waters level)

Lignite seam thickness: –average 6.4 m + +

Lignite seam isolation : clays-like - ( v. shallow) +/-

Sulphur content -0,89 wt.% + Not defined/ -

Preliminary evaluation of posibilities of the methodsapplication -examples

Sulphur content -0,89 wt.% + Not defined/ -

Humidity- 50 wt.% -/+ +

Temperature in the seam- ca. 12-16 C no influence +/- (season depending, winter – risky)

Location (s.a.: c.a. 27 ha) + +

1414

RUSKORUSKO--JAROSZÓW (Piotrowice region)JAROSZÓW (Piotrowice region)RUSKORUSKO--JAROSZÓW (Piotrowice region)JAROSZÓW (Piotrowice region)

Parameter Thermal Biological

Reserves of lignite deposit- balance resources – 6041 th. Mg + +

Lignite rank and quality: 7.2 MJ/kg, ash cont. 31.0 wt.% - +

Lignite seam depth : 11 m bgl - shallow +/-

Lignite seam thickness : average 5 m + +

Lignite seam isolation : clays-like - shallow +/

Preliminary evaluation of posibilities of the methodsapplication -examples

Lignite seam isolation : clays-like - shallow +/

Location - -

Temperature No influence +/- (season depending, winter -risky)

Sulphur content: 1.8 wt. % -/+ -

SchematicSchematic geologicalgeological crosscross--sectionsection of of selectedselectedlignitelignite depositdeposit

SchematicSchematic geologicalgeological crosscross--sectionsection of of selectedselectedlignitelignite depositdeposit

Seam A

Seam B

Concept of an hybrid method with complementary use of Concept of an hybrid method with complementary use of thermal and biological gasificationthermal and biological gasification

Concept of an hybrid method with complementary use of Concept of an hybrid method with complementary use of thermal and biological gasificationthermal and biological gasification

� injection well drilling to upper seam A and production (monitoring) well drilling

� nutrients injection

� layers sealing around injection well

A- biomass culture and/or nutrient preparation (mobile unit)

B-Module of seampreparation injection wellC- Unit for gas purification, retention and transmission

D-Unit of biogas take-off

E- PCS, pumps system and 1-2 retention ponds

Concept of an hybrid method with complementary use of Concept of an hybrid method with complementary use of thermal and biological gasificationthermal and biological gasification

Concept of an hybrid method with complementary use of Concept of an hybrid method with complementary use of thermal and biological gasificationthermal and biological gasification

�Injection well deepening to lignite seam B

�Horizontal drilling of production well(s) for thermal gasificationwell(s) for thermal gasification

�Site preparation: construction of feeding module: oxygen tank(1), compressors and process control panel (2), syngas purification module: first step of cleaning(3) -tar and ash particles removal, scrubbers for sulphur compounds removal (4)

Concept of an hybrid method with complementary use of thermal and biological gasification

Concept of an hybrid method with complementary use of thermal and biological gasification

oxygen tank(1),

compressors and process control panel (2),

�gasification by CRIP method in Seam B

�additional result -heat production and transfer from gasifier to surrounding

syngas purification module: first step of cleaning(3) -tar and ash particles removal,

scrubbers for sulphur compounds removal (4)

to surrounding geological layers

heat transfer fromSeam B to Seam A is expected

HeatHeat transfer transfer arroundarround gasifiergasifier --BloodwoodBloodwood CreekCreek-- realrealexampleexample ((MalettMalett C., C., CarbonCarbon Energy USG Energy USG projectproject update,2011update,2011))HeatHeat transfer transfer arroundarround gasifiergasifier --BloodwoodBloodwood CreekCreek-- realrealexampleexample ((MalettMalett C., C., CarbonCarbon Energy USG Energy USG projectproject update,2011update,2011))

Concept of an hybrid method with complementary use of thermal and biological gasification

Concept of an hybrid method with complementary use of thermal and biological gasification

A- biomass culture and/or nutrient preparation (mobile unit)

B-Module of seampreparation

�continuous monitoring of nutrients and atmosphere in seam A,

�the distance 30-40m between A & B seams will allow to heat transfer between them

C- Unit for gas purification, retention and transmission

D-Unit of biogas take-off

E- PCS, pumps system and 1-2 retention ponds.

transfer between them ( C. Mallett, 2011)

�After few months from nutrients injection first biogas will be expected

Probably slight rise of temperature will enhance the biogas production

PreliminaryPreliminary laboratorylaboratory teststests for a for a selectedselected casecase

Case of a selected lignite seams: performed and planned lignite and surrounded rocks analyses

Case of a selected lignite seams: performed and planned lignite and surrounded rocks analyses

Basic characteristics of lignite samples :1. Technical analyses2. Elemental analyses3. Termogravimetric tests4. Thermal gasification of lignite chars with CO2-Reactivity tests5. Pyrolysis gas composition 6. Basic microbiological analyses7. Properties of geological formations from surroundings of lignite seams

Lignite rocks: several lignite parameters were determined in order to evaluate possibility of biogasification method application (porosity, surface area, permeability, quantity of pores bigger then 1 µm [%], pore diameter, etc.)

- ppermeability of the samples is too low in order to assure technological liquids flow and sufficient microorganisms/rock contact – fracking will be needed (preliminary tests are being conducted).contact – fracking will be needed (preliminary tests are being conducted).

Surroundings rocks:Seam A:

overburden clays -like layers with permeability 1.0-1.6 *10-11 m/sunderburden clays -like layers with permeability 0.5-3.3 *10-10 m/s

Seam B: -overburden- clays -like with permeability 1.0-1.6 *10-11 m/s-underburden clays-like layers with permeability 0.9-2.6 *10-11 m/s and -----------------------------------------------------------------------------------------------------------------------Planned analysesRock –Eval analysis,• Characteristics of chemical content of extracted organic matter,• Characteristics of chemical content of macromolecular fractions of lignites.•Detailed biogasification tests

ReactivityReactivity teststestsReactivityReactivity teststests

�� ThermogravimetricThermogravimetric teststests

tailored to 1st order kinetics

Tests conditions:

�temperature range 40 - 1000 ° C

�argon atmosphere (pyrolysis stage)

�CO2 atmosphere(gasification stage)

� three fixed heating rates, 3, 10, 30 K min–1.

( ) (1 )f α α= −

Seam A

( ) ( )

( ) (1 )f

dk T f

dT

α αα α

= −

=

lignite samples form seams A & B have similar kinetic in

pyrolysis and gasification stage

Seam B

______

.…………experimental data

model

Parameters and composition of gas obtained by pyrolysisParameters and composition of gas obtained by pyrolysis

Lignite seam A B Combustion heat of gas

MJ/m312.5 15.9

Calorific value of gas 11.5 14.5

Composition of gas obtained by pyrolysis

H2 6.53 7.26

O2 0 0.04

N2 0.5 0.86

CO 7.05 5.92

CH4 9.22 10.26

CO2 40.3 34.6

C2- C5 3.1 4.8obtained by pyrolysisof lignite

% by volume (v/v) C2- C5 3.1 4.8

H2S >2.00 >2.00

COS 0.068 0.192

CH3SH 0.348 0.661

CS2 0.000 0.017

C4H4S 0.001 0.003

Microbiological analysesMicrobiological analyses

�� MethodsMethods for for isolationisolation and and identificationidentification of of microorganismsmicroorganisms: :

�� commoncommon techniquestechniques of of morphologicalmorphological propertiesproperties evaluationevaluation, , microscopicmicroscopic methodsmethods, , selectiveselectiveculturescultures, , biochemicalbiochemical propertiesproperties evaluationevaluation (Mini API system/(Mini API system/BiomerieuxBiomerieux, , othersothers), ),

�� identificationidentification basedbased on DNA on DNA analysesanalyses ((PCRPCR--polimerasepolimerase chainchain reactionreaction and and analisisanalisis of of thethecodingcoding sequencessequences of of genetiggenetig materialmaterial))

�� SignificantSignificant numbernumber of of anaerobicanaerobic and aerobic and aerobic microorganismsmicroorganisms ableable to to useuse organicorganic compoundscompounds as a as a sole sole sourcesource of energy and of energy and carboncarbon for growth, for growth, werewere isolatedisolated form form lignitelignite samplessamples ((c.ac.a. 60 . 60 microbialmicrobial speciesspecies isolatedisolated) ) MetabolismMetabolism of of somesome of of themthem isis fermentationfermentation--likelike –– theythey areare ableable to to produceproduce substartessubstartes for for methanogenesismethanogenesis ((otherother thenthen COCO22).).

�� DifferentDifferent organicorganic compoundscompounds werewere testedtested for for biodegradationbiodegradation

�� BothBoth heterotrophicheterotrophic bacteriabacteria and and fungifungi werewere determineddetermined to to growgrow on on lignitelignite samplessamples ((preservedpreserved inin�� BothBoth heterotrophicheterotrophic bacteriabacteria and and fungifungi werewere determineddetermined to to growgrow on on lignitelignite samplessamples ((preservedpreserved ininnonnon--oxicoxic environment)environment)

Microorganisms isolated from polish lignite samples were able to decompose several organic compounds, that may be precursors of

biogenic methane

Microbiological Microbiological analysesanalyses

� Examples of bacteria and fungi species isolated: Arthobacter, Rhodocococcus, Streptomyces, Pseudomonas , Burkholderia, Serratia, Talaromyces, etc.

� Sulphate reducing bacteria were also determined to be active in the cultures(Desulfovibrio, Desulfomicrobium)

Streptomyces sp.

Pseudomonas sp.

Lignite sample kept in non-oxicenvironment covered with some fungi

Rhodococcus sp.

SummarySummary posibilityposibility of of hybridhybrid methodmethodapplicationapplication for for selectedselected lignitelignite seamsseamsSummarySummary posibilityposibility of of hybridhybrid methodmethodapplicationapplication for for selectedselected lignitelignite seamsseams

Parameter Thermal Biological

Seam A Seam B Seam A Seam B

Reserves of lignite deposit - + + +

Lignite rank and quality - + + -

Lignite seam depth - + + -

Lignite seam thickness - + + +/-

Lignite seam isolation : clays-like - + + +Lignite seam isolation : clays-like - + + +

Sulfur content + +/- + -

Humidity -/+ + + +/-

Temperature in the seam- ca. 12-16 C no influence no influence +/- (season depending)

+/- (season depending)

Location + + + +

ThankThank youyou for for youryour attentionattentionThankThank youyou for for youryour attentionattentionContact details:

Magdalena Król, email: mkrol@cuprum.wroc.pl

Agnieszka Szubertemail: aszubert@cuprum.wroc.pl

KGHM CUPRUM Ltd. -KGHM CUPRUM Ltd. -R&D Centre

Gen. Wł. Sikorskiego 2-8, 53-659 Wroclaw, PolandTel: +48 71/ 781 22 01Fax: +48 71/ 344 35 36

e-mail: kghm@cuprum.wroc.pl