Transcript File - Ben Franklin Technology Partners Shale Gas

Marcellus Shale Wastewaters
Management by Resource
Recovery
Shale Gas Innovation Contest
Ben Franklin Technology Partners
April 13, 2012
Timothy Keister, CWT , Chief Chemist
ProChemTech International, Inc.
51 ProChemTech Drive
Brockway PA
Marcellus Shale Wastewaters
The Marcellus Shale is the
largest natural gas
development in North
America
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Each well produces
200,000 to 1+ million
gallons of flowback
wastewater during
hydrofracture
Production wastewater is
expected to average 200 to
4000 gpd per well
Shale wastewaters contain
high levels of many
constituents
Marcellus Deposit Outlined in Blue
Typical Wastewater Chemistry
barium (toxic heavy metal)
calcium
chloride
iron
magnesium
sodium
strontium
dissolved solids
total hardness as CaCO3
suspended solids
6,500 mg/l
18,000 mg/l
116,900 mg/l
60 mg/l
1,300 mg/l
48,000 mg/l
4,000 mg/l
195,000 mg/l
54,500 mg/l
1,200 mg/l
Resource Recovery is the
Environmentally Sound Means to
Manage Marcellus Shale
Wastewaters
ProChemTech International, Inc. has
developed a sequential precipitation
fractional crystallization technology that
converts Marcellus shale wastewaters into
salable commodities
Step 1 - Clarification
As flowback and production
wastewaters are delivered to the
treatment facility, they are treated
by passage through a free oil and
solids separator, inclined plate
clarifier, as delivered. Clarified
wastewater is then pumped to an
aerated chemical equalization tank.
Tank capacity is set to equal daily
system throughput.
Step 2 - First Precipitation
Clarified wastewater is pumped to a series of
mix tanks where the following chemicals are
added:
• sulfuric acid
• potassium permanganate
• sodium hydroxide
• anionic polymer
Step 3 - Barite Removal
Under the specific conditions of pH and
ORP obtained in the step 2 chemical
additions, barium is completely precipitated
as a commercial purity barium sulfate.
Iron, manganese, and radioactives present
are also removed and incorporated into the
barite.
Radioactivity level of the barium sulfate
is equal to commercial barite samples
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Precipitated barite is removed from the
wastewater stream using an inclined plate
clarifier as a liquid sludge.
Liquid sludge is dewatered using a plate and
frame filter press, washed, discharged, and
air dried prior to sale as commodity barite.
Barite use in the United States in 2004 was
about 2.65 million tons, 79% imported
Note: Our first barium sulfate system was designed
and built in 1990 for MuRata Electronics
Step 4 - Strontium Recovery
Optionally, strontium can be recovered from the
barium stripped wastewater by addition of
sulfuric acid, sodium hydroxide, and anionic
polymer under defined conditions to precipitate
strontium sulfate. The strontium sulfate is then
removed by an inclined plate clarifier,
dewatered, and dried as the barium sulfate.
Step 5 - Factional Crystallization
Distilled Water Production
• Barium and strontium stripped wastewater is
pumped to an evaporator-crystallizer
• Steam from the evaporator-crystallizer is
condensed using a heat exchanger to preheat
the wastewater entering the unit - producing
distilled water
• In the evaporator-crystallizer, the wastewater
concentrates by water loss due to evaporation
• Of the three major salts present in the stripped
wastewater, sodium chloride is the least soluble
followed by magnesium and calcium chloride
• Sodium chloride fractionally crystallizes from the
the concentrating wastewater and is removed by
sidestream filtration
• At concentrated calcium chloride levels of above
approximately 34%, the sodium chloride level has
been reduced to less than 2.5%, resulting in a
salable commodity calcium chloride solution
Step 6 Sodium Chloride Purification
• Sodium chloride crystals removed by sidestream
filtration are washed with distilled water and dried
• Fractional crystallization produces a very high
quality sodium chloride product which is suitable
for a large number of commercial uses
• Sodium chloride use in the United State is many
millions of tons per year
Step 7 Calcium Chloride Product
Process and Quality Control
• Commercial calcium chloride solution has to contain 28 to
40% calcium chloride by weight with less than 2.5% sodium
chloride present.
• The sidestream removed from the evaporator-crystallizer will
be monitored by specific gravity, after sodium chloride crystal
removal, and when within specification diverted to a calcium
chloride solution holding tank
• Energy recovery will be accomplished via preheat of the
spent sodium chloride wash water as it is returned to the
evaporator-crystallizer
• Calcium chloride is 46 th volume chemical produced in
United States
Current Status
• Process has been laboratory bench tested on four actual
production wastewaters and the products analyzed
• A pilot scale unit is needed to confirm the laboratory testing
and to provide data for process scale up to commercial sized
units, PADEP pilot plant permit in final stage of approval
• Major pilot plant question concerns specific design of
evaporator - crystallization unit, which is the single most
costly equipment item
• Investors require pilot plant operation to prove viability of
process and to generate product samples for buyer evaluation
• Two process patents filed to date
• Additional R&D is planned to examine bromine and lithium
recovery
Late News Flash
The Program Committee of the International
Water Conference has accepted the paper by
Timothy Keister titled “Sequential
Precipitation - Fractional Crystallization
Treatment of Marcellus Shale Flowback and
Production Wastewaters” for presentation at the
73 rd Annual International Water Conference,
San Antonio, TX, November, 2012
Thank You - Questions
PCT Sequential Precipitation Fractional Crystallization
Process - Right to Left
raw water - barite - stripped brine - sodium chloride crystal
calcium chloride solution - distilled water