Mitigation of Methane Emissions from Coal Mine Ventilation Air

1
Mitigation of Methane Emissionsfrom Coal Mine
Ventilation Air
Western States Coal Mine Methane Recovery and Use
Workshop Grand Junction, Colorado April 19-20,
2005

• H. Lee Schultz
• Manager, Environmental Programs, BCS Inc.,
  Columbia, MD
• Richard Mattus
• Business Manager, MEGTEC Systems, De Pere, WI
• F. Peter Carothers
• Senior Engineer, Methane Mitigation, IRG,
  Washington, DC

April 19-20, 2004
2
Presentation Overview

• Background on VAM
• VAM Technologies - Capturing VAM
• VAM Technologies - Use Options for VAM
• VAM Oxidation
• VAM Oxidation with Energy Recovery
• Large scale plant for electricity from VAM
• Emerging Energy Recovery Technologies
• EDL
• CSIRO Lean Fuel Gas Turbine
• Ingersoll-Rand
• FlexEnergy
• CSIRO Liquatech Hybrid
• Concentrator
• Recent Developments
• Conclusions

3
Background on VAM

• Ventilation air methane (VAM) is largest CMM
  source
• Has been difficult to capture and use
• Large airflows 100,000 to 1 million cfm (47 to
  470 m3/s)
• Low concentrations 0.1 to 1.0, typically 0.3
  to 0.5
• Variable, both flow and concentration
• Little technology available, until now
• CMOP is investigating VAM capture and use
  technologies
• Two major reports, technical assistance, etc.

4

• Global Marginal Abatement
• Cost Curve

VAM Power Production
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VAM Technologies Capturing VAM

• Several designs available
• Direct versus indirect
• Pull slip stream or re-channel entire flow
• Concerns are
• Cannot affect airflow pressure or velocity from
  evasé (diffuser)
• Assure separation of mining environment from VAM
  recovery plant environment
• Mining regulators in several countries are
  reviewing designs

6
VAM Technologies Use Options for VAM

• Ancillary
• VAM supplements primary fuel, (e.g., gob gas,
  natural gas, coal, etc.)
• Combustion air for IC engines, gas turbines,
  coal-fired plants, etc. - Appin Tower
  Collieries, Australia)
• Principal
• VAM is primary fuel, (e.g., in oxidizers, gas
  turbines, etc.)
• Example West VAMP project in Australia

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Oxidation of VOC (Volatile Organic Compounds)
Spontaneous
With catalyst
Grade of Oxidation
760 C (1400 F)
Temperature
1000 C (1830 F)
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VAM Oxidation

• Two Oxidation Systems Currently Available
• MEGTEC Systems, a US corporation, manufactures
  the VOCSIDIZER
• Thermal flow-reversal reactor (TFRR) with
  oxidation at full temperature without catalyst
• 700 units sold globally to industries for VOC
  emission control
• Demonstrated at coal mines in UK and Australia
• CANMET, a Canadian laboratory, developed a
  catalytic flow-reversal reactor (CFRR), the
  CH4MIN
• Catalyst allows oxidation in a cooler range than
  TFRR below
• Tested at bench scale for prolonged periods

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VAM Oxidation - Catalytic

• Schematic of a CFRR (Double Bed)

Heat Exchange Medium
Valve 2
Valve 1
Catalyst
Heat Exchange
Air C02, H20 Heat
Air CH4
Catalyst
Heat Exchange Medium
Valve 1
Valve 2
Valve 1 open Valve 2 open Heat recovery
piping not shown
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VAM Oxidation - Catalytic

• Schematic of a CFRR (Double Bed)

Heat Exchange Medium
Valve 2
Valve 1
Catalyst
Heat Exchange
Air C02, H20 Heat
Air CH4
Catalyst
Heat Exchange Medium
Valve 1
Valve 2
Combustion chamber
Valve 1 open Valve 2 open Heat recovery
piping not shown
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VAM Oxidation - Thermal

• Schematic of a VOCSIDIZER (Single Bed)

Heat Exchange Medium
Valve 2
Valve 1
Heat Exchange
Air C02, H20 Heat
Air CH4
Heat Exchange Medium
Valve 1
Valve 2
NO combustion chamber
Valve 1 open Valve 2 open Heat recovery
piping not shown
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The Flameless VOCSIDIZER
20oC / 70 F
1000oC / 1830 F
60oC / 140 F
Flameless Oxidation completely in-bed. No
NOx No flame. Homogeneous temp distribution
without peaks. Start-up Heating elements in
centre of ceramic bed. Heat efficient Self
sustaining at low concentrations (0.1 of
methane).
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VOCSIDIZER PRINCIPLE OF OPERATION
Flow down
Vent air without methane
Vent air with methane
Flow up
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VOCSIDIZER VAM ABATEMENT
1st INSTALLATION AT A COAL MINE - abating vent
air methane in 1994
TRIAL UNIT AT BRITISH COAL Demonstration of
abatement 8000 m3/h of ventilation air with 0.3
0.6 methane. Abatement self sustaining at 0.1
methane.
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RECOVERING ENERGY FROM VOCSIDIZER BED
Steam
Superheated steam
Steam
Water
Rule of thumb Energy content of CH4 above 0.2
can be recovered, i.e. at 0.4 CH4, 50 can be
recovered (0.2 CH4) at 1.0 CH4, 80 can be
recovered (0.8)
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VOCSIDIZER VAM PRIMARY FUEL FOR GENERATÍON OF
ENERGY
2nd INSTALLATION AT A COAL MINE - small scale
generation of energy
ACARP Award 5 April 2005 Best Australian
Greenhouse Gas Project
2001 - 2002
TRIAL UNIT AT APPIN COLLIERY, BHP AUSTRALIA
2001 - 2002 Demonstration of heat recovery 6000
m3/h of ventilation air 90 recovery as hot
water. Operated during 12 months.
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VOCSIDIZER STEAM CYCLE FOR POWER GENERATION
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OPTIONAL COOLING ENERGY
Example 800 000 m3/h 1 methane 72 MW(th)
18 MW(el) 16 MW(el) 38
MW(cool) (at 25 turbine eff)
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LARGE SCALE VOCSIDIZER PLANT VAM PRIMARY FUEL
FOR GENERATÍON OF ENERGY
3rd INSTALLATION AT A COAL MINE - first large
scale generation of energy
Principle Layout
INSTALLATION FOR BHP Billiton AUSTRALIA
2005 Demonstration of large scale heat
recovery 250 000 m3/h (150 000 SCFM) of
ventilation air generating 6 MW of electricity
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LARGE SCALE VAM PRIMARY FUEL FOR GENERATÍON OF
ENERGY
An installation taking the full flow of
ventilation air of a major mine generates approx
20 - 25 Mwe
and reducing GreenHouse Gas emissions by approx
1 million CO2te per year.
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Emerging Energy Recovery Technologies

• Energy Developments Ltd.s - Carbureted Lean-Fuel
  Gas Turbine
• Contact Tom Chapman, EDL, Tom.Chapman_at_edl.com.au
• Fuel Enriched VAM 1.6 methane
• Output 2.7 MW from a SOLAR Centaur gas turbine
• Feature Special carbureted combustor
• Development Undergoing endurance testing
• Commonwealth Scientific and Industrial Research
  Organisation (CSIRO) - Lean-Fuel Gas Turbine
• Contact Dr. Shi Su, CSIRO, Shi.Su_at_csiro.au
• Fuel Enriched VAM 1.0 methane
• Output Electric power from a gas turbine (to be
  selected)
• Feature Catalytic combustor
• Development Planning prototype unit fabrication
  and testing

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Emerging Energy Recovery Technologies

• Ingersoll-Rand (IR) - Lean-Fuel Microturbine
• Contact Patrick Reinks, IR, Patrick_reinks_at_irco.c
  om
• Fuel Enriched VAM 1.0 methane and below
• Output Electric power from small gas turbines
• Feature Patented recuperator
• Development In prototype testing phase at 250 kW
• FlexEnergy - Lean-Fuel Microturbine
• Contact Edan Prabhu, FlexEnergy,
  edanprabhu_at_cox.net
• Fuel Enriched VAM 1.5 methane
• Output 30 kW (will be higher)
• Development Field testing underway

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Emerging Energy Recovery Technologies

• CSIRO Liquatech Hybrid Coal and Gas Turbine
  System
• Contact Dr. Cliff Mallett, CSIRO,
  Cliff.Mallett_at_csiro.au
• Fuel VAM and waste coal
• Output 1.2 MW (demonstration unit)
• Features VAM and unprocessed waste coal combust
  in rotary kiln.
• Development Laboratory trials and 1.2 MW
  prototype tests complete
• VOC Concentrator
• Research to date
• EPA commissioned Environmental CC, Inc. to run
  tests on a fluidized bed adsorber
• ECC selected an adsorbent, but performance was
  less than hoped for
• ECC continues to search for improved adsorbent
• Primary use would be to upgrade VAM to optimum
  inlet concentration for other technologies

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Recent Developments

• DOE EPA providing cost-sharing grant to CONSOL
  Energy for oxidation demonstration project in US
  
• Project delayed as MSHA evaluates safety aspects
  of VAM capture approaches
• Underground equipment?
• Permissibility?
• Appropriate connection to evasé
• As interim measure, DOE, EPA and CONSOL looking
  at test case using abandoned mine methane as
  source and manipulating flows and concentrations
  to simulate various mine ventilation flows

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Conclusions

• USEPA is now investigating VAM mitigation
• VAM comprises the largest source of methane
  emissions from coal mines
• VAM presents technical challenges
• Huge airflows
• Very dilute
• Energy conversion can be difficult
• Oxidizers lead the commercialization race
• Other technologies getting closer
• Important greenhouse gas emissions reduction
  impact as much as 200 million tonnes CO2e per
  year

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For More Information

• For more information on VAM technologies and
  marketsContact USEPA Coalbed Methane Outreach
  Program
• Clark Talkington [phone]
  (talkington.clark_at_epa.gov)
• Pamela Franklin [phone] (franklin.pamela_at_ep
  a.gov)
• Or visit the Ventilation Air Methane portion of
  the programs web site at www.epa.gov/coalbed.

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The Authors

• H. Lee Schultz [phone], ext. 221
• lschultz_at_bcs-hq.com
• Richard Mattus 46-705-22 66 10
• rmattus_at_megtec.se
• F. Peter Carothers [phone]
• pcarothers_at_worldnet.att.net