Emulsion Breakers: POLYMERS FOR OIL/WATER SEPARATION

Tramfloc® all-organic liquid polymers and emulsion breakers are highly effective in oil recovery and produce water quality suitable for reuse from waste and slop oil, coolant, coking, oil field, utility, mining, petroleum and refining applications. Tramfloc® all-organic liquid polymers effectively precipitate heavy metals, improve supernatant quality, increase solids recovery, produce a denser rag layer and a clean, high quality oil phase in demulsification applications, and also reduce sludge production.

Tramfloc® all-organic polymers are non-hazardous and biodegradable. They are completely miscible in water and meet environmental regulations. Tramfloc® polymers will meet your plant’s requirements for suspended matter, emulsified oils, metal cutting fluids, water soluble coolants, hydrocarbon oils, and supernatant quality.

Tramfloc® all-organic liquid polymers are aqueous blends of surfactants and copolymers especially designed to assist in the reversing of the emulsification process. Ammonium, acrylamide and other non-hazardous all-organic components are used to manufacture Tramfloc® polymers.

When plants apply Tramfloc® All-Organic Liquid Polymers, TAOLP, the operations usually become more efficient and costs are reduced while profits are increased. Call Tramfloc, Inc. to explore better ways to deal with entrained and emulsified hydrocarbons.

Emulsion Breakers: DAF and API Equipped Systems

Tramfloc custom designed polymers  and emulsion breakers for oily waste treatment.

Oil in water waste streams can coat and damage equipment, contaminate process water and escape treatment in biological systems. Treatment of oily waste streams using emulsion breakers can result in:

  • Improved oil/water separation
  • Improved water clarity
  • Oil recovery
  • Water reuse
  • Protection of downstream facilities
  • Environmental permit compliance

Oily wastewater is classified by the form of the oil/water mixtures, i.e., free liquid (nonemulsified) or emulsion.

Free liquids are commonly separated by gravity. In most situations the oil is lighter than water and can be separated by physical operations such as skimming or flotation. The principles governing gravity separation of oil are expressed by Stoke’s Law:

[Emulsion Breakers: Stoke's Law Formula]

where:

V = oil droplet rise rate
g = acceleration due to gravity
dw = water density
do = oil density
D = oil droplet diameter
u = water viscosity

As defined by Stoke’s Law, the rise rate of the oil droplet can be varied by changing the oil density, water viscosity, water density or the oil droplet size. Temperature controls the first three variables, while the addition of chemical coagulants will alter the last variable, oil droplet size.

Emulsions are stable mixtures of two immiscible liquids. Emulsions are stabilized by an emulsifying agent (the emulsion breaker) which is a film of surface active agents that reduces the interfacial tension between the oil and water. The film of emulsifiers can be altered by heat, chemicals, mechanical devices or a combination of the three.

Polymers are used to destabilize oily wastewaters on many types of equipment, such as: the American Petroleum Institute (API) separator, Corrugated Plate Interceptor (CPI) separator, Induced Air Flotation (IAF) and Dissolved Air Flotation (DAF). Figure 1 is a schematic of a DAF. A flow schematic of a typical refinery waste treatment system is shown in Figure 2.

[Emulsion Breakers: Dissolved Air Flotation Unit] 
[Emulsion Breakers: Refinery Waste Treatment Plant]
Tramfloc has developed a bench scale test to simulate the operation of a dissolved air flotation system. This test is particularly useful in determining operating parameters such as pressure requirements, recirculation ratios, chemical requirements and rise rate estimations.

Most emulsions are treated either on a batch basis or as a continuous process. The treatment process employs chemical addition, pH adjustment and heat to destabilize the emulsified oils. Tramfloc has developed a laboratory procedure to test the effectiveness of Tramfloc cooking chemicals in breaking oil emulsions. Tramfloc personnel can then determine the required dosage of polymer by a full scale trial.

Tram-Oil Series products are ideal for treatment of either free or emulsified oils. These products are surface active polymeric liquids of very high charge density which alter the oil droplet size. In combination with a cooking operation, Tram-Oil products are particularly effective in destabilizing emulsified oils (synthetic, waste cutting, rolling, hydraulic and other soluble oils) in water.

The advantages of emulsion breakers and our Tramfloc products include:

  • Production of smaller sludge volume than inorganic coagulant products
  • Reduction of sludge handling and hauling costs
  • Improved oil/water separation
  • Improved water clarity and recycling of acid water
  • Greater oil recovery and better quality oil for reuse
  • Tram-Oil Series products are more tolerant of pH variations than inorganic coagulants

The Tramfloc approach to successful treatment of free and emulsified oils employs proven product technology. Tramfloc products are recommended on the basis of detailed system surveys, laboratory and full-scale testing, computer simulations and analyses. The Tramfloc approach is designed to provide the best treatment for oily waste streams.

Emulsion Breakers: WASTE AND SLOP OIL TREATMENT

Tramfloc, Inc. manufactures a wide variety of demulsification products, emulsion breakers, Tram-OilTM having application in the treatment of waste and slop oils. Each compound marketed for the application has been field proven prior to commercialization.

This paper contains information on the treatment of typical waste oils and a set of typical formulations suitable for this application. As with all emulsification (emulsion breaking) applications, performance is strongly influenced by the composition of the emulsion and any contaminants present, as well as its previous treatment history. For this reason, it is strongly recommended that operators conduct their own bottle testing prior to field applications. WASTE OIL(also referred to as slop oil, pit oil or reclaim oil) accumulates as a by-product of the oil production and refining processes. They are usually generated when an upset or accident occurs; hence their production is rarely planned or convenient. Waste oils are usually very tightly emulsified and frequently contain a variety of external contaminants. Some of the more common contaminants are such items as formation fines, dirt, clay, drilling mud solids, scale solids and iron compounds, usually corrosion by-products. Paraffin in the form of wax, and asphaltenes may also be present. The aqueous portion of the emulsion usually consists of oilfield brine waters, though spent acid, caustic, polymers or fractionating fluids are not uncommon. A free water phase may also present. In many cases, the waste oil may contain chemicals of various natures, in either the hydrocarbon or the aqueous phases. These often are present as a result of previous attempts to resolve the waste oil emulsion. When an upset occurs at a production facility, it is common for an attempt to be made to resolve the waste oil by sending it through the production system again. This may be done more than once. This can lead to a condition where the lighter, short chain carbon fractions have been driven off by repeated heating. It is common to do this in conjunction with the injection of additional demulsification chemical.?br> If this process is unsuccessful, the waste oil takes on a dark, “sludgy” appearance, often with the presence of darker specs distributed through out. Waste oils in this condition are termed over-treated or “burnt”. The oil takes on the properties of a semi-combusted oil, and an additional contaminant is added, residual carbon from the over-treatment process. Waste oil treatment is often very involved, so it is common for operators to let waste oils accumulate until they can be resolved at one time. Since waste oils are generally stored until the volume is sufficient for economical treatment, the resulting waste oil is usually a composite from several sources. Storage conditions (pit versus vessel) and time of storage may complicate the treatment process. As a result of its’ origin, handling and composition, treatment of waste oil requires that it be treated as a unique problem. A solution to one waste oil emulsion may not be applicable to another, although the techniques of separation may be similar. Treatment of waste oil generally follows standard oilfield philosophy, in that the ideal solution consists of recoverable oil suitable for sale, and water and TSS components subject to further treatment modalities. Bottle testing with effective Tramfloc Emulsion Breakers will maximize the amount of recovered oil. Successful treatment of waste oil is dependent on proper utilization of the following techniques and conditions.

1. Heat

2. Chemical Application

3. Agitation

4. Retention or Quiescent Time

Heat is usually required to resolve water oil emulsions. Typical treatment temperatures range from 45 degrees F to 185 degrees F. Exceptions both higher and lower exist, and some oils may be treated at ambient temperatures. Chemical application consists of three major areas: demuslification and pH adjustment. Demulsifer formulations are utilized to chemically separate, or aid in the separation of the two phases comprising the emulsified waste oil. These formulations are designed to resolve the emulsion without over-treatment characteristics. Typical treatment rates range from 500 PPM to 5000 PPM. Treatment ranges vary widely, depending upon paraffin wax volume and composition, as well as the API gravity of the waste oil. The adjustment of pH may be done with caustic or acid. This adjustment may be critical to resolving the waste oil emulsion. Typically, the pH is adjusted in small increments or to a relatively neutral state by addition of the appropriate amounts of acid or base. Application rates are typically 250 PPM to 1500 PPM or .25 to 1.0 pounds per barrel. In addition to these types of chemical treatments, surfactants are sometimes required for resolution of solids, viscous oil-water interfaces and sludging. Agitation is usually essential to disperse the chemical treatment and to obtain uniform heating. A number of methods exist to provide agitation. Generally speaking, use of transfer pumps is not recommended as the shear affect may stabilize or re-emulsify the waste oil. Retention time allows time for the treatment process to work. A minimum period of 8 to 24 hours is recommended. Times in excess of this minimum are common. With many waste oils, the addition of water as a wash may expedite the treatment process. This wash application can aid in solids removal and if relatively fresh water is entrained in the waste oil, aid in the water drop. The water used may range from fresh to brine in terms of salinity.

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