Developing a Diverse CMM

Industry including VAM Utilisation

Dr Cliff Mallett

Acting Chief, CSIRO Exploration and Mining

Technology Court, Pullenvale, Qld 4069, Australia

cliff.mallett@csiro.au

Methane to Markets Ministerial Meeting, 15-17 November 2004

Coal mine methane emissions-1

Mine CH4:

In Australia: ~6% of GHG production

World total: VAM - over 200 MMT CO2e in 2000 (from US

EPA report).

Coal-related methane emission sources:

Underground ventilation

70%

R & D focus

Open cut mining

Surface handling

Abandoned mines 1%

5%

4%

Underground drainage

20%

from IEA report 1

Mine methane emissions-2

Underground 9PRE-DRAINAGE

– High CH4 conc ~ 95%,

– Relatively consistent flow.

9POST-DRAINAGE – Medium CH4 conc ~(>30%),

– Rapid change in flow rate.

9VENTILATION AIR – Huge amount, 150~300m3/s

– Variable CH4 conc

What can we do with the mine methane?

Combustion

thermal oxidation

catalytic oxidation

Purification to make pipeline gas Feedstock for chemicals

methanol carbon black

3

Map of potential technologies

Mine Methane Low Concentration Medium-High Hybrid

Concentration Mitigation Use Mitigation Use Use

Thermal TFRR, Catalytic CFRR, Catalytic CMR.

Catalytic turbine, Recuperative turbine, Catalytic + 2nd heat, Power station air,

Flare. Purify, Gas engines, Gas turbines, Fuel cells,

Fluidised bed, Rotating kiln.

Air for engines, Air for turbines,

Co-firing, Feedstock.

Concentrator (?)

4

Technologies for drainage gas

Purification: pipeline gas

Power generation/cogeneration Reciprocating gas engine

Conventional gas turbine

Co-firing in power stations

Fuel cell power generation

(electrochemical reaction)

Chemical feedstocks Methanol production

Carbon black production

5

Technologies for ventilation air methane -1

Ancillary uses

substituting the ventilation air for ambient air in combustion processes

Limited sites or small volumes used not in case studies

Principal uses combustion of the methane in ventilation air as a primary fuel

• Thermal flow-reversal reactor (TFRR), • Catalytic flow-reversal reactor (CFRR), • Catalytic monolith reactor (CMR), • Catalytic lean-burn gas turbine, • Recuperative lean-burn gas turbine, • Enriching process (?, not in case studies)

6

Technologies for ventilation air methane - 2

Principal use technologies

CH4 mitigation Feature MEGTEC CANMET CSIRO

TFRR CFRR CMR Principles of operation Flow reversal Same as TFRR Monolith reactor

No Yes Yes 1000oC 350~800oC 500oC

Catalyst Auto-ignition temperature Experience Some field units Bench-scale trials with Bench-scale study on

operating on methane simulated mine exhaust combustion Cycle period length Shorter Longer Continuously Minimum CH4 0.2% 0.1% 0.4% concentration Applicability CH4 mitigation CH4 mitigation CH4 mitigation

4 4 4

Possibility of recovering heat to generate power

Need additional fuel to increase CHconcentration and maintain it constant

Need additional fuel to increase CHconcentration and maintain it constant

Need additional fuel to increase CH concentration and maintain it constant

Variability of CH4 Variable Variable Variable concentration Plant size Huge Larger Compact Operation More complicated More complicated Simple Lifetime N/A N/A >8,000 hours for catalysts, NOx emission N/A Low Low (

Technologies for ventilation air methane - 3

CH4 mitigation & utilisation

Feature EDL CSIRO Ingersol-Rand

Recuperative Turbine Catalytic Turbine Catalytic Microturbine Principles of Air heater inside Monolith reactor Monolith reactor operation combustion chamber Catalyst No Yes Yes Auto-ignition 700~1000oC 500oC N/A temperature Experience Pilot-scale trial Bench-scale study on Conventional microturbine

combustion development

4 1% 1%

CH4

4

CH4

CH4

CH4

4

Cycle period length Continuously Continuously Continuously Minimum CHconcentration for operation

1.6%

Applicability mitigation and power generation and need additional fuel to increase CHconcentration

mitigation and power generation and need additional fuel to increase

concentration

mitigation and power generation and need additional fuel to increase CH concentration

Possibility of Feasible (power Feasible (power Feasible (power generation) recovering heat generation) generation) Variability of CH4 Constant Constant Constant concentration Operation Simple and stable Simple and stable Simple and stable Lifetime May be shorter due to >8,000 hours for catalysts, N/A

the high temperature and 20years for a turbine. combustion heat exchanger

NOx emission N/A Low (

Technologies for ventilation air methane & drainage gas

No single technology provides an easy solution

Combined units can give benefits Example: 1% methane turbine and conventional gas engine power plant system can maximise the mitigation and utilisation of all of mine methane.

9

Case studies of two mines

Technical & economic assessment of the implementation of most of the above technologies into an Australian mine

Technical feasibility • Range of technologies, 95% availability, maximum capacity

Economics • determine major economic parameters: capital cost,

operational cost, IRR, net present value, break-even cost

• basic case – plant lifetime: 25 years, – installation cost: 10% of equipment capital cost, – discount rate: 7.5%, – electricity price: AU$37/MW•hr, – natural gas price: $5.05/GJ, – no carbon credit.

10

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Case study-Mine 1

CH4 emissions at mine

3 /s

0

50

100

150

200

CH

4 co

nc, %

CH4

3 /s

0

1

2

3

4

CH

4

40

50

60

70

80

90

100

CH4

3 /s

CH

4

20

40

60

80

100

CH4

Ventilation air Flo

w r

ate,

m

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

Flow rate concentration

Pre-drainage gas Flo

w r

ate,

m

con

c, %

Flow rate concentration

Post-drainage gas Flo

w r

ate,

m

0.0

0.5

1.0

1.5

2.0

2.5

3.0

con

c, %

Flow rate concentration

1/1/

02 1

2:00

:00

AM

2/1/

02 1

2:00

:00

AM

3/1/

02 1

2:00

:00

AM

4/1/

02 1

2:00

:00

AM

5/1/

02 1

2:00

:00

AM

6/1/

02 1

2:00

:00

AM

7/1/

02 1

2:00

:00

AM

8/1/

02 1

2:00

:00

AM

9/1/

02 1

2:00

:00

AM

10/1

/02

12:0

0:00

AM

11/1

/02

12:0

0:00

AM

12/1

/02

12:0

0:00

AM

1/1/

03 1

2:00

:00

AM

Date, time

Case study-Mine 1

CH4 emissions at mine

(Based on average values)

Vent air: 32,433,515 m3/year, 32.8%

Drainage: 66,475,933 m3/year, 67.2%

Mine ventilation methane is contained in 5.4 billion m3 of air

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Case study-Mine 1

CH4 at mine site

9 Biggest CH4 concentration variation rate:

0.01%/hour in vent air

9 CH4 in Ventilation air: min 0.2%, max1.44%, average 0.56%

9 CH4 in drainage gas: average 79.2% for Pre, 71.8% for Post

9 Pure CH4 flow in drain gas: 2.11m3/s

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Case study-Mine 1

15

Gas E

ngi

ne

Gas T

urbi

ne

1% T

urbi

ne

1.6%

Tur

bine

1%

& En

gine

1.

6% &

Engi

ne

t

0

20

40

60

80

100

120

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

200000

4

4

4

4

Comparison of plant sizes and electricity production P

lant

siz

e, M

W

Ele

ctri

city

, MW

h, d

urin

g th

e 31

9 da

ys

Gas Engine - Gas engine power plant Gas Turbine - Gas turbine power plant 1% Turbine - 1% CH lean-burn turbine plant

1.6% Turbine - 1.6% CH lean-burn turbine plant

1% & Engine - combined 1% CH lean-burn turbine and gas engine power plant

1.6% & Engine - combined 1.6% CH lean-burn turbine and gas engine power plant

Plant size Electricity

16

Per

cent

age

of v

enti

lati

on a

ir m

etha

ne

bein

g m

itig

ated

/uti

lise

d, %

Per

cent

age

of d

rian

age

gas

be

ing

mit

igat

ed/u

tili

sed,

%

Case study-Mine 1 Comparison of methane mitigation and utilisation

TFFR

CFRR

CM

R PS

A Ga

s Eng

ine

Gas T

urbin

e 1%

Turb

ine

1.6% T

urb

ine

1%& E

ngin

e

1.6%

&En

gine

0

20

40

60

80

120

0

20

40

60

80

120 Ventilation air Drainage gas

100 100

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Case study-Mine 1

Amount of mitigated/utilised mine methane

Mit

igat

ed/u

tili

sed

met

hane

, m3

TFFR

CF

RRCM

R PS

A Ga

s Eng

ine

Gas T

urbin

e 1%

Tur

bine

1.6% T

urbin

e

1%&

Eng

ine

1.6%

&En

gine

0

20000000

40000000

60000000

80000000

100000000

0

200000

400000

600000

800000

1000000

1400000 /Mitigated utilised methane

Mitigated CO2-e 1200000

Mit

igat

ed C

O2-

e, t

18

e

Turb

ine

1%Tu

e e 1%

&En

gine

1.

6%& E

nge

20

40

60

80

140

20000

40000

60000

80000

100000

120000

140000

220000

Case study-Mine 2 (Typical gassy mine) 9 ~64% CH4 emitted with ventilation air 9

Potential of the 1% CH4 turbine for ventilation air methane at typical gassy mines!

P lan t s ize E lectric ity

Analysis summary of plant size and electricity production

200000

120

180000

160000 100

0 0

n nn

Gas

Engi

nG

as

r

ibi rbi

6%Tu

Pla

nt s

ize,

MW

t

Ele

ctri

city

, MW

h pe

r ye

ar

1.

Mine methane mitigation and policies

Applications in Australia

National Greenhouse Strategy – framework

National Carbon Accounting System – publishes data

Greenhouse Abatement Program – provides capital

German Creek, Teralba, Bellambi mines (gas engines)

West Cliff (TFRR – MEGTEC)

NSW Greenhouse Abatement Certificates NGAC

Credits are owned by owner of facility that does the mitigation example – Kiln with waste coal & mine methane

National renewable scheme – mine wastes excluded

although municipal waste methane included

Current research projects in CSIRO

Characterisation and cleaning of mine ventilation air

flows (Shi Su), Technical and economic issues on mine methane

mitigation and utilisation (Shi Su),

Development of a small pilot-scale demonstration unit of

1% CH4 catalytic turbine (Shi Su), International networking on greenhouse gas (CH4)

mitigation (Shi Su), Coal mine greenhouse gas measurement – Australian

practice (John Carras), Monitoring methane emissions from open cut mining

(John Carras).

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In CLOSING

Before a successful deployment of any technology, the following important issues need to be resolved: is the technology proven?

no decrease in mine safety and compliance with all

regulatory standards,

profitable economics using the methane energy and

carbon reduction revenues,

who owns ventilation air methane/CMM,

units have to be portable.

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