430F98082
           United States
           Environmental Protection Agency
                                           Air and Radiation
                                           6202J
Draft
October 1997
oEPA
    EPA Coalbed Methane Outreach Program Technical Options Series
COAL MINE METHANE USE IN BRINE WATER TREATMENT
         Coal Mine Methane-Fueled Evaporator at Morcinek Mine, Poland
             (Photo Courtesy of Aquatech Services, Incorporated)


AN INTEGRATED APPROACH TO DISPOSAL OF PRODUCED BRINES

+ Wastewater treatment process uses coal mine methane as fuel

+ Can be an economically viable alternative to other water management
  methods

* Appropriate for coal mines and coalbed methane fields producing large
  volumes of saline water

* Produces fresh water suitable for domestic, industry, or agriculture usage

+ Can use medium quality gas (as low as 50 percent methane)

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 The use of coal mine
 methane enhances
brine water treatment
   economics while
reducing emissions of
   methane to the
    atmosphere
  Desalination plants
  typically have large
fuel requirements, and
coal mine methane is
a clean, low-cost fuel
     Desalination
   processes (unlike
     underground
    injection) can
 produce fresh water
  for crop irrigation,
    domestic, and
     industry use
Why Consider Coal Mine Methane Use in Brine Treatment?

Coal mines and coalbed methane wells often generate large volumes of water,
which may be highly contaminated with salt and other minerals. Because these
brines can alter water quality,  they must be disposed of in compliance with
national and local statutes.  Energy producers are continually seeking to improve
economics by decreasing water management costs.

Many coal mines  drain methane from gob areas (collapsed rock over mined-out
areas).  Mine ventilation air contaminates gob gas, often rendering it unsuitable for
pipeline injection.  Therefore, mines usually vent this gas to the atmosphere instead
of using it.  By using this gas as a fuel in the brine water treatment process, coal
mines can reduce the cost of desalination while helping to mitigate greenhouse
gas emissions.

Over the  last three  years, the  use of coal mine methane in brine  water
desalination has been successfully demonstrated at the Morcinek coal mine in
Poland's Upper Silesian Coal Basin.  The process, designed by Aquatech Services,
ncorporated, integrates pre-treatment  regimes,  high-pressure reverse osmosis,
and a final concentration of the salt in a submerged combustion evaporator.  The
pretreatment regime  is specially designed for the complex waste streams typical
of coalbed brines. Following pretreatment, a reverse osmosis system converts the
brine wastewater  to usable fresh water and a  brine-salt slurry.  Evaporation units,
fired by  medium-quality  gas  recovered  from  the  Morcinek  Mine,  further
concentrate the  residual slurry to dry salts for commercial use  or underground
disposal.

The demonstration project at the Morcinek Mine is treating more than 50 cubic
meters  (314  barrels)  of waste  water  per day.   Testing  of the demonstration
equipment began in  1994, with support from the U.S. Department of Energy, U.S.
Environmental Protection Agency, and Polish government.  All results have been
positive, demonstrating efficiencies greater than anticipated, and validating and
confirming process reliability.

Some Facts About  Using Coal Mine Methane for Waste Water Treatment
    (based on results of the demonstration project at the Morcinek Mine)

   Treatment costs are competitive with those of underground injection

   Modular design allows for wide range of effluent volumes

   Process can  recover more than 60% of the feed stream as usable fresh
    water, suitable for domestic uses in many cases

   Process offers total brine volume reductions of greater than 95%

   Suitable for coalbed methane wells in unmined areas, as well as coal mining
    operations

   Can use medium quality gas (as low as 50% methane)

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          Example of Aquatech Wastewater Treatment Process
                          Chemical Pre-Treatment

                             Filter
                  High
                Pressure
                 Pump
                                                                      Reverse
                                                                      Osmosis
                                                                       Unit
                                                            250m3/ day
                                                             of brine,
                                                        TDS = 80 -120,000 ppm
                                                             v  Pump
                                                     Submerged
                                                     Combustion
                                                     Evaporator
                             , Underground
                                Disposal
      Comparison of Aquatech Process (Using Coal Mine Methane as
                  Combustion Fuel)  to Underground Injection
                                 Reverse Osmosis Followed          Underground
           Parameter                 by Combustion                 Injection
                                  Evaporation (Aquatech}              Only(}]
 Typical capital costs  ($US)            $3,000 per m3/day       $1,260 - $5,660 per m3/day
	I     $480 perbbl/day     i    $200 - $900 per bbl/day
 Typical operating costs ($US)
$2.00-$3.00/m3(2)
$0.32-$0.47/barrel
 $0.60- $4.70/m3
$0.10-$0.75/barrel
 Conversion to usable water
       YES
       No
Production of usable salts
Uses coal mine methane'31
Total brine volume reduction
Life ot plant or well (years)
1 YES (in some cases) ]
I YES |
! >95%
! 10
No
No
0%
20
  (1> Underground injection costs and well life vary widely according to site-specific conditions. Costs shown are from
 1995 assessment of water disposal practices in the U.S., published by the Gas Research Institute (GRI), and from an
 unpublished report on disposal of produced waters in the San Juan Basin prepared in 1992 for GRI.  Costs shown do
 not include off-site transportation.  Twenty years is the average injection well life according to Warner and Lehr,
 1977, An Introduction to the Technology of Subsurface Wastewater Injection: A symposium in Worthington, Ohio.
  121 On a lease-purchase basis
  (3) Coalbed methane can be an economical fuel source for treatment of water produced from coal mining
 operations or coalbed methane wells.  Use of methane produced during coal mining operations is especially
 attractive in that in most cases, this methane would otherwise be vented to the atmosphere. This "waste gas" is a
 valuable fuel source if mines use it, otherwise, it is a potent greenhouse gas that causes global warming.	

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  For More Information.
  Energy producers are continually seeking to
  improve economics by decreasing  water
  management costs. Coal mine  methane
  used as fuel for a wastewater treatment
  process   is  an  economic  means  of
  wastewater management that can also
  reduce  emissions  of  methane  to the
  atmosphere.

  EPA  is  aware  of  only  one  company
  (Aquatech Services, Incorporated) whose
  brine  water treatment  process  has em-
  ployed coal mine methane  as a fuel.* To
  obtain more information about this process,
  contact:

  John H. Tait, Principal
  Aquatech Services, Incorporated
  P.O. Box 946
  Fair Oaks, CA 95628 USA
        (916) 966-5141 (Phone and Fax)
  e-mail 103220.1655@compuserve.com
 Or contact EPA's Coalbed Methane Outreach
 Program for information about this and other
 profitable uses for coal mine methane:
  Coalbed Methane Outreach Program
  U.S. EPA
  401 M Street, SW(6202J)
  Washington, DC 20460 USA
         (202) 564-9468 or (202) 564-9481
  Fax:   (202) 565-2077
  e-mail: fernandez.roger@epa,gov
         schultz.karl@epa.gov

         http://www.epa.gov/coalbed
C  O  A
METHANE
OUTREACH
 '  R O C  R A M
*The mention of products or services in this case study does not constitute an endorsement by EPA.

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