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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.
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Marcellus Shale Wastewaters Management by Resource Recovery Shale Gas Innovation Contest Ben Franklin Technology PartnersApril 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 • 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) 6,500 mg/l calcium 18,000 mg/l chloride 116,900 mg/l iron 60 mg/l magnesium 1,300 mg/l sodium 48,000 mg/l strontium 4,000 mg/l dissolved solids 195,000 mg/l total hardness as CaCO3 54,500 mg/l suspended solids 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
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 CrystallizationDistilled 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