How does an electrostatic desalter work?
An electrostatic field is applied by electrodes in the settling tank, inducing polarization of the water droplets floating in the larger volume of oil. This results in the water droplets clumping together and settling to the bottom of the tank.
What are the main parameters that affect the efficiency of the desalter?
Five parameters which are affecting the efficiency of the desalter unit are; temperature, demulsifier injection rates, wash-water injection rates, differential pressure, and electrical current.
What is the function of desalter in CDU 1?
Figure 1 below is a schematic flow diagram of a typical CDU and, as can be seen, the desalter (colored red for clarity) is typically installed in the heat exchange train that heats the incoming crude oil before it flows through a fired heater and into the distillation tower.
What is the pH maintained in desalter?
The wash waters have a pH 5.5 – pH 7.00 contaminated with Ammonia and Phenols Temperatures can > 100 C, and the brine effluent waters contain sulphides, heavy metals, and oil – this cocktail is often very abrasive. Electrode fouling and poisoning is a risk.
Why is desalter important?
The purpose of a desalting system is to reduce the salt content of the treated oil to acceptable levels. When the salinity of the produced brine is not too high, merely ensuring that there is a low fraction of water in the oil can reduce salt content.
What is the API gravity of water?
… petroleum industry, however, uses the American Petroleum Institute (API) gravity scale, in which pure water has been arbitrarily assigned an API gravity of 10°.
How do you remove Sulphur from fuel oil?
The process of removing SCC from the fuel oil includes two steps: oxidation using hydrogen peroxide and a catalyst and extraction of oxidized sulfur compounds with aqueous acetonitrile.
What is desalter process?
Desalting involves mixing heated crude oil with washing water, using a mixing valve or static mixers to ensure a proper contact between the crude oil and the water, and then passing it to a separating vessel, where a proper separation between the aqueous and organic phases is achieved.
Why salt is undesired in crude oil?
The large concentration of salt in crude oil can contribute to the mechanical clogging of furnace tubes, condensers, and lines by deposition, the corrosion of equipment by the hydrolysis of salts producing hydrogen chloride, and high ash content of still residues throughout the refinery process .
What is API formula?
The formula for API gravity is API = (141.5/SG) -131.5 where SG is the specific gravity of the petroleum liquid being measured. For example, for an API gravity of 50, add 131.5 to obtain 181.5. Divide 141.5 by (131.5 + API gravity) to obtain the specific gravity of the oil.
What is emulsion breaker?
Emulsion breakers, also known as demulsifiers, are a group of specialty chemicals used to separate emulsions of water-in-oil and oil-in-water (reverse emulsions). These chemicals are used for effective oil recovery, and to improve the quality of reusable water.
What kind of technology is used to help remove sulfur?
Sulfur removal is typically carried out by using caustic or soda ash as in Eqs (20.1) and (20.2). Desulfurized paste is separated in a filter press and sent to the furnace while sodium sulfate solution goes to the crystallizer.
What is the process of removing sulphur from diesel?
Hydrodesulfurization (HDS) is the current industrial method to remove aliphatic and acyclic sulfur-containing compounds from diesel oil. This process is usually applied using CoMo and NiMo-type catalysts and allows removing sulfur compounds by their conversion to H2S , .
Why is Sulphur removed from crude oil?
Desulfurization is the process of removing sulfur from crude oil (or its fractions). It prevents contamination and also improves the efficiency of petroleum. Desulfurization removes elemental sulfur and its compounds from solids, liquids and gases.
How do you reduce Sulphur in oil?
Hydrodesulfurization is the most commonly used method in the petroleum industry to reduce the sulfur content of crude oil. In most cases HDS is performed by co-feeding oil and H2 to a fixed-bed reactor packed with an appropriate HDS catalyst.
How is API measured?
The American Petroleum Institute gravity, or API gravity, is a measure of how heavy or light a petroleum liquid is compared to water: if its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks.
How do you calculate API value?
API stands for the American Petroleum Institute, which is the industry organization that created this measure.
- Calculation of API gravity.
- API = (141.5/Specific Gravity) – 131.5.
- API gravity of crude oil grades.
What is the difference between specific gravity and API gravity?
API gravity is thus an inverse measure of a petroleum liquid’s density relative to that of water (also known as specific gravity). It is used to compare densities of petroleum liquids. For example, if one petroleum liquid is less dense than another, it has a greater API gravity.
What is the SG of oil?
Specific Gravity Resource
|Liquid||SG @ 60°F / 15.6°C|
|Carbon Tetrachloride CCl4||1.59|
|Crude Oil||0.79 – 0.86|
How do you separate emulsions?
Gravity separation is the most widely used method for oil emulsion separation. The elements in the well stream such as oil and water have different gravities. The density differences allow water to separate by gravity. With enough time in a non-turbulent state, the differing specific gravities will naturally separate.
What is rag layer?
In oil sands froth treatment an undesirable intermediate layer often accumulates during the separation of water-oil emulsions. The layer referred to as ‘rag’ is a complex mixture of water, oil, solids and interfacially active components.
How do you deactivate sulfur?
- Hydrogen peroxide: Hydrogen peroxide system completely removes manganese, iron, and sulfur in well water, making it one of the most effective sulfur eradication systems.
- Ozone: Another powerful oxidizer, ozone proves to be highly effective on large amounts of sulfur.