Crude Oil Refining Flashcards
___________ also known ___________ are saturated compounds that have the general
formula CnH2n+2
, where n is the number of carbon atoms.
Paraffin also known as alkanes
___________________ are branched-type hydrocarbons that exhibit structural
isomerization.
Isoparaffins (or isoalkanes)
__________ also known _________, are unsaturated hydrocarbons containing
carbon–carbon double bonds.
Olefins, also known as alkenes,
Compounds containing carbon–carbon triple bonds
are known and are also known as ________ or ________
biolefins or alkynes
_____________ also known as ___________, are saturated hydrocarbons that have
at least one ring of carbon atoms.
Naphthenes, also known as cycloalkanes
__________ are unsaturated cyclic compounds composed of one or more benzene
rings.
Aromatics
The _________ content of crude oils varies from less than 0.05 to more than 10 wt% but
generally falls in the range 1–4 wt%.
sulfur
The _______ content of crude oil is usually less than 2 wt%.
oxygen
Crude oils contain very _________________________________
low amounts of nitrogen compounds
Metallic compounds exist in all crude oil types in very small amounts.
a. Nickel (Ni)
b. Vanadium (V)
Give the 7 products from crude oil
Gasoline, Jet fuel, Asphalts, Petroleum Coke, Lube oil, Diesel & Kerosene, Liquid Petroleum Gas
Poor desalting has the following effects:
- Salts deposit inside the tubes of furnaces and on the tube bundles of heat
exchangers creating fouling, thus reducing the heat transfer efficiency; - Corrosion of overhead equipment; and,
- The salts carried with the products act as catalyst poisons in catalytic cracking
units.
how is DESALTING work
When the crude oil enters the unit, it carries with it some brine in the form of very
fine water droplets emulsified in the crude oil. The salt content of the crude
measured in pounds per thousand barrels (PTB) can be as high as 2000. The salt
content should be lowered to between 5.7 and 14.3 kg/1000 m3
(2 and 5 PTB).
HOW DESALTER UNIT WORKS?
- Water washing: Water is mixed with the incoming crude oil through a mixing
valve. The water dissolves salt crystals and the mixing distributes the salts into
the water, uniformly producing very tiny droplets. - Heating: The crude oil temperature should be in the range of 48.9–54.4 ̊C since
the water–oil separation is affected by the viscosity and density of the oil. - Coalescence: The water droplets are so fine in diameter in the range of 1–10
mm that they do not settle by gravity. Coalescence produces larger drops that
can be settled by gravity. This is accomplished through an electrostatic electric
field between two electrodes. The electric field ionizes the water droplets and
orients them so that they are attracted to each other. - Settling
DISTILLATION
Crude distillation unit (CDU) is at the front-end of the refinery, also known as
topping unit, or atmospheric distillation unit.
VACUUM DISTILLATION
- extract more distillates
- type of distillation performed under reduced pressure
SOLVENT DEASPHALTING (SDA)
only physical process where carbon is rejected from heavy petroleum
fraction such as vacuum residue.
A well-known solvent deasphalting process is the ROSE process, an energy
efficient and cost-effective solvent deasphalting technology.
ROSE process, an energy
efficient and cost-effective
SOLVENT EXTRACTION
It is a technique in which a solute can be separated from a solution by shaking the solution with a solvent in which the solute is more soluble and the added solvent does not mix with the solution.
SOLVENT DEWAXING
Dewaxing process in petroleum refining is removal of wax.
* The feedstocks to dewaxing include DAO from deasphalting, and HVGO fromvacuum distillation along with some compositional characteristics of thefeedstock and the dewaxing product.
* Wax (long-chain paraffins) obtained in dewaxing is a marketable by-product.
* Lubricating oil base stock is the principal product of interest
* The main purpose of dewaxing is to remove hydrocarbons that solidify readily(i.e., wax) for making lubricating oil base stock with low pour points
what is DESALTING
is processing equipment in the refinery that removes salt and other impurities from crude oil. Desalter in a refinery is one of the major components. It is typically the first unit towards cleaning and processing crude oil and its distillation.
What Distillation
separates the crude oil into different products according to their individual boiling ranges.
