Title: Thermal Oxidation of Coal Mine Ventilation Air Methane VAM
1Thermal Oxidation of Coal Mine Ventilation Air
Methane (VAM)
12th U.S./North American Mine Ventilation
Symposium Reno, Nevada, USA, June 9 -11, 2008
- J. M. Somers
- USEPA, Coalbed Methane Outreach Program
- H. L. Schultz
- BCS Incorporated
2Presentation Overview
- Background on VAM
- Flow-reversal Oxidizer Technology
- VAM Oxidation Demonstration History
- WestVAMP
- CONSOL Windsor Mine Demonstration
- JWR Mine Demonstration
- Technology Deployment Challenges
- Technology Deployment Benefits
- Conclusions
3Background on VAM
- Methane is a powerful greenhouse gas
- More than 20 times as potent as CO2
- Mine safety regulations require gassy underground
coal mines to assure that methane concentrations
in the mine workings are maintained at safe
levels - Well below the lower explosive limit (5 in air)
- Mines employ large scale ventilation systems to
vent methane to the atmosphere - Methane drainage can supplement ventilation
4Background on VAM
- Ventilation air methane (VAM) is largest source
of coal mine methane (CMM) emissions - 54 of all U.S. CMM emissions in 2005
- Capturing and using VAM is challenging
- 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
- Thermal flow-reversal oxidizers in use worldwide
for industrial air pollution control offer a
solution
5Global VAM emissions (2002)
- Emission world
- Country (Bm3) Total
- China 6.7 38.7
- United States 2.6 15.0
- Ukraine 2.2 12.7
- Russia 0.7 4.0
- Australia 0.7 4.0
-
- Total World 17.3
6Background on VAM
- Technology options
- Thermal (Biothermica, MEGTEC)
- Catalytic (CANMET)
- Operational modes
- Oxidation only
- Oxidation with energy recovery (e.g., electricity
generation) - Available systems
- Commercial project - MEGTEC Systems (DePere
Wisconsin, USA) - http//www.megtec.com
- Demonstration planned - Biothermica (Montreal,
Canada) - http//www.biothermica.com
- Prototype - CANMET Energy Technology Centre
(Varennes, Canada) - http//www.nrcan.gc.ca/se/etb/cetc/cetc01/htmldocs
/home_e.htm
7Flow-reversal Oxidation Technology
Heat Exchange Medium
Valve 2
Valve 1
Heat Exchanger
Air C02, H20 Heat
Air CH4
Heat Exchange Medium
Valve 1
Valve 2
Valve 1 open Valve 2 open Heat recovery
piping not shown
8VAM Thermal Oxidation History
- MEGTEC VOCSIDIZER?
- 1994 Oxidation only - Thoresby Mine, UK
- 2001-2002 Oxidation and steam generation
Appin Colliery, Australia - 2007 Oxidation and electricity generation
West Cliff Colliery, Australia - 2007 Oxidation only Abandoned Windsor Mine
(CONSOL Energy), West Liberty, West Virginia - Biothermica VAMOX?
- 2008 Jim Walter Resources Mine, Brookwood,
Alabama, USA - In planning stages
- Active mine
- MSHA approval received!
9JWR Mine Demonstration
- Employs a single Biothermica VAMOX? unit
- Capacity 30,000 cfm VAM concentration 0.9
percent - Greenhouse gas emission mitigation gt40,000
tonnes of CO2e per year - Revenues Carbon emission reductions
- Projected lifetime gt 4 years
10WestVAMP
- West Cliff Ventilation Air Methane Project
- Startup April 2007
- Capacity 250,000 m3/hour (150,000 scfm) of mine
exhaust air - VAM concentration 0.9 percent
- Generation unit steam turbine
- Electricity output 6 MW
- Four VOCSIDIZER? units
- Ongoing project with two revenue sources
- Electricity
- Carbon credits traded in New South Wales trading
scheme
11WestVAMP
12CONSOL Windsor Mine Demonstration
- Using diluted, drained CMM to simulate VAM
- Employs a single MEGTEC VOCSIDIZER? unit
- Operates unattended
- Goals are to verify
- Ability to maintain VAM oxidation
- System safety
- Operability and maintenance requirements under
field conditions - Capacity 30,000 scfm of simulated VAM
- VAM concentration 0.6 percent
13CONSOL Windsor Mine Demonstration
14CONSOL Windsor Mine Demonstration
- Results
- Ability to operate on VAM concentration below 1
percent verified - System safety features verified
- Responded appropriately to upsets (e.g., power
outage) - Field operation and maintenance experience gained
15Technology Deployment Challenges
- Lack of technology knowledge and field experience
- Availability of supplemental methane to raise VAM
inlet concentrations to near 1 percent - To maximize energy output, and therefore energy
production revenues - Most VAM concentrations exiting the mine are
significantly below 1 percent) - To maximize carbon emission reduction revenues
- One study estimates that attractive payback times
(3 to 6 years) can be achieved at VAM
concentrations above 0.6 percent with carbon
emission reduction sale prices at or above 10.00
per tonne CO2e
16Technology Deployment Benefits
- Ability to mitigate the largest source of coal
mine emissions worldwide - Capability to capture and beneficially use VAMs
dilute energy content - Adds to energy security by beneficially using a
currently wasted energy source - Multiple vendors should lead to cost competition
that will drive down project capital costs - Higher return on investment
- Shorter payback time
17Conclusions
- Flow-reversal oxidation of VAM with power
generation is a proven technology - Field demonstrations are multiplying
- Potential global market for VAM-to-power
applications is large - Emerging cost competitiveness should enhance
project economics
18Thank You
- Jayne Somers
- U.S. Environmental Protection Agency
- Manager, Coalbed Methane Outreach Program
- Washington, DC, USA
- Somers.jayne_at_epa.gov
- www.epa.gov/coalbed
- H. Lee Schultz
- Manager, Environmental Programs
- BCS Incorporated, Laurel, MD, USA
- lschultz_at_bcs-hq.com