• Saturday, June 18, 2016

    The most important questions of oil refining companies

    اهم اسئله التكرير الخاصه بالشركات

    اهم اسئله التكرير الخاصه بالشركات


     Cryogenic process

    cryogenics is the cooling of materials to extremely low temperatures using highly condensed gases. the shown is used to transport liquefied gases used in cryogenic processes.

    cryogenics involves refrigeration at temperatures below 120 kelvin. these low temperatures, which are not natural on earth, make it possible to liquefy gases such as methane, oxygen, nitrogen and hydrogen. the cryogenic plant show is used to produce liquefied natural gas

    Dehydration

    Electrostatic desalting is employed for both oil field and refinery applications, to facilitate the removal of inorganic chlorides and water-soluble contaminants from crude oil. In refinery applications, the removal of these water-soluble compounds prevents or minimizes damage to downstream distillation equipment.

    Vacuum 

    Vacuum distillation is a part of the refining process that helps to produce petroleum products out of the heavier oils left over from atmospheric distillation.

    Vacuum distillation is the distillation of liquids performed at a pressure lower than atmospheric pressure to take advantage of the fact that reducing the pressure lowers the boiling point of liquids.

    Gross (or high, upper) Heating Value

    The gross or high heating value is the amount of heat produced by the complete combustion of a unit quantity of fuel

    The gross heating value is obtained when

    all products of the combustion are cooled down to the temperature before the combustion
    the water vapor formed during combustion is condensed

    Net (or lower) Heating Value

    The net or lower heating value is obtained by

    subtracting the latent heat of vaporization of the water vapor formed by the combustion
    from the gross or higher heating value.

    Common Units

    Common units for heating value

    1 Btu/lb = 2326.1 J/kg = 0.55556 kcal/kg
    1 J/kg = 0.00043 Btu/lb = 2.39x10-4 kcal/kg
    1 kcal/kg = 1.80 Btu/lb = 4187 J/kg

    what's the difference between a pump and a compressor

    Pump is a device which is used to increase the pressure of 
    (incompressible fluids (liquid fluids

    Compressor is a device which is used to increase the pressure of 
    (compressible fluids(gaseous fluids

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    ?what is the term of API and its equation

    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
    Conversely, the specific gravity of petroleum liquids can be derived from their API gravity value as

    Crude oil is classified as light, medium, or heavy according to its measured API gravity

    Light crude oil has an API gravity higher than 31.1° (i.e., less than 870 kg/m3)
    Medium oil has an API gravity between 22.3 and 31.1° (i.e., 870 to 920 kg/m3)
    Heavy crude oil has an API gravity below 22.3° (i.e., 920 to 1000 kg/m3)
    Extra heavy oil has an API gravity below 10.0° (i.e., greater than 1000 kg/m3)

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    Sensible heat 

    When an object is heated, its temperature rises as heat is added. The increase in heat is called sensible heat. Similarly, when heat is removed from an object and its temperature falls, the heat removed is also called sensible heat. Heat that causes a change in temperature in an object is called sensible heat

    Latent heat 

    All pure substances in nature are able to change their state. Solids can become liquids (ice to water) and liquids can become gases (water to vapor) but changes such as these require the addition or removal of heat. The heat that causes these changes is called latent heat

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    ?Definition - What does Reboiler mean

    Reboiler is a heat exchanger used for providing heat to the bottom of the industrial distillation columns. The liquid is heated from the bottom of the distillation column in order to generate vapors that are returned to a column for driving distillation separation. A proper operation of a reboiler is essential for effective distillation. All vapors that drive the separation come from a reboiler in the typical column of classical distillation. The reboliers receive a stream of liquid from the bottom of the column and may completely or partially vaporize that stream. This stream of liquid offers heat required for vaporization