Perhaps more importantly, the small gas bubbles are attracted to surface-active material and, hence, to the water droplets thus, they tend to keep the water droplets from settling and might even cause them to be discharged with the oil.įuel is required to provide heat, and so the cost of fuel must be considered. In vertical emulsion treaters and gun barrels, some liberated gas could rise through the coalescing section, creating enough turbulence and disturbance to inhibit coalescence. The gas that is liberated when crude oil is treated also might create a problem in the treating equipment if the equipment is improperly designed. In special cases, increased heat might cause the density of water to be less than that of oil. For heavy crudes ( < 20☊PI), which normally are treated above 180☏, heat might have a negative effect on the density difference. Because most light oils are treated below 180☏, the effect of heat on gravity is beneficial. In general, at temperatures below 180☏, adding heat will increase the density difference. Heat also might increase the density difference between the oil and the water Molecular movement, which helps coalescence by causing the dispersed-phase droplets to collide more frequently.Į.g., dissolve paraffin crystals), or might enhance the action of treating chemicals, causing the chemical to work faster and more thoroughly to break the film around the droplets of the dispersed phase of the emulsion. Viscosity should be < 7 cSt for desalting. 12L recommends that crude oil be heated so that its viscosity is 50 cSt for dehydration. If the viscosity is unknown at any temperature, the chart’s curves may be used. Viscosity that is known at one temperature can be approximated at other temperatures by drawing a straight line parallel to the curves already on the chart. If a crude oil’s viscosity is known at two temperatures, it can be approximated at other temperatures by drawing a straight line along those temperature/viscosity points on the chart. Crude-oil viscosities vary widely, and the curves on this chart should be used only in the absence of specific data. 1 can be used to estimate crude-oil viscosity/temperature relationships. Which allows the water droplets to collide with greater force and to settle more rapidly. 1.3 Heat also might increase the density difference between the oil and the water.1.2 Heat might deactivate the emulsifier.1 Heat reduces the viscosity of the oil.These include PAOs and also relatively common polyisobutenes (PIB), which are sometimes used as oil additives or as base oils in two-stroke engines. Several synthetic base oil types fall into the SHC category. The term synthetic hydrocarbon (SHC) is a general term. Polyalphaolefins also have poor fire resistance and biodegradability. Therefore, they are commonly blended or combined with organic ester synthetic base oils to provide a blended base oil that does not have these negative characteristics. These include the tendency to shrink seals and trouble dissolving common oil additives. However, nothing is perfect, and polyalphaolefin base oils do have a few negative characteristics. One application in which they have not worked well is in high-temperature (high-pressure) reciprocating air compressors where valve deposits have been an issue. They are also employed as base fluids in some wide temperature range greases. PAOs are used extensively in automotive fluids as well as hydraulic, gear and bearing oils, working in extremely cold climates or hot applications. This lowers their volatility, creates less hydrocarbon tailpipe emissions and raises the flash point. Because of their controlled structure, PAOs do not contain lighter, more volatile (small) hydrocarbons. The absence of these structures and materials results in a very non-polar base oil with a high viscosity index (of approximately 130), excellent low-temperature flow and pour-point characteristics, good oxidation stability and compatibility with mineral oils, paints and seals commonly found in lube oil systems. Polyalphaolefin does not contain ring structures, double bonds, sulphur, nitrogen components or waxy hydrocarbons. It is a synthetic hydrocarbon (SHC) that mimics the best hydrocarbon (branched) structure found in mineral oils. Polyalphaolefin is by far the most common major synthetic base oil used in industrial and automotive lubricants.
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