Part 1 Flashcards
_____, also known as alkanes, are saturated compounds that have the general formula CnH2n+2, where n is the number of carbon atoms.
Paraffins
______ (or isoalkanes) are branched-type hydrocarbons that exhibit structural isomerization.
Isoparaffins
also known as alkenes
olefins
olefins are _____ containing carbon–carbon double bonds
unsaturated hydrocarbons
Compounds containing carbon–carbon triple bonds are known and are also known as _____ or alkynes.
biolefins
also known as cycloalkanes
Naphthenes
naphthenes are _____ that have at least one ring of carbon atoms.
saturated hydrocarbons
_____ 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
_____ contain very low amounts of nitrogen compounds.
Crude oils
_____ exist in all crude oil types in very small amounts.
Metallic compounds
Metallic compounds
a. Nickel (Ni)
b. Vanadium (V)
Crude oil comes from different parts of the world and has different _____ characteristics.
physical and chemical
crude oil products
• LPG
• Gasoline
• Diesel & Kerosene
• Jet fuel
• lube oil
• asphalt
• petroleum coke
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).
Desalting
effects of poor desalting
• fouling
• corrosion
• catalyst poison
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.
water washing
how desalter unit works
• water washing
• heating
• coalescence
• settling
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.
heating
_____ 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.
coalescence
_____ is at the front-end of the refinery, also known as topping unit, or atmospheric distillation unit.
Crude distillation unit (CDU)
To extract more distillates from the atmospheric residue, the bottom from the atmospheric CDU is sent to the _____. This are classified as light vacuum gas oil (LVGO) and heavy vacuum gas oil (HVGO).
vacuum distillation unit
• This is the only physical process where carbon is rejected from heavy petroleum fraction such as vacuum residue.
• This oil is also called ‘Bright Stock’’ and is used as feedstock for
lube oil plant.
solvent deasphalting (SDA)
In this process, lube oil stock is treated by a solvent, such as N-methyl pyrrolidone (NMP), which can dissolve the aromatic components in one phase (extract) and the rest of the oil in another phase (raffinate). The solvent is removed from both phases and the raffinate is dewaxed.
solvent extraction
The raffinate is dissolved in a solvent (methyl ethyl ketone, MEK) and the solution is gradually chilled, during which high molecular weight paraffin (wax) is crystallized, and the remaining solution is filtered. The extracted and dewaxed resulting oil is called ‘‘lube oil’’. In some modern refineries removal of aromatics and waxes is carried out by catalytic processes in ‘‘all hydrogenation process’’.
solvent dewaxing
