4 (part 1)

Question 1

_____, also known as alkanes, are saturated compounds that have the general formula CnH2n+2, where n is the number of carbon atoms.

Answer 1

Paraffins

Question 2

______ (or isoalkanes) are branched-type hydrocarbons that exhibit structural isomerization.

Answer 2

Isoparaffins

Question 3

also known as alkenes

Answer 3

olefins

Question 4

olefins are _____ containing carbon–carbon double bonds

Answer 4

unsaturated hydrocarbons

Question 5

Compounds containing carbon–carbon triple bonds are known and are also known as _____ or alkynes.

Answer 5

biolefins

Question 6

also known as cycloalkanes

Answer 6

Naphthenes

Question 7

naphthenes are _____ that have at least one ring of carbon atoms.

Answer 7

saturated hydrocarbons

Question 8

_____ are unsaturated cyclic compounds composed of one or more benzene rings.

Answer 8

Aromatics

Question 9

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%.

Answer 9

sulfur

Question 10

The _____ content of crude oil is usually less than 2 wt%.

Answer 10

oxygen

Question 11

_____ contain very low amounts of nitrogen compounds.

Answer 11

Crude oils

Question 12

_____ exist in all crude oil types in very small amounts.

Answer 12

Metallic compounds

Question 13

Metallic compounds

Answer 13

a. Nickel (Ni)
b. Vanadium (V)

Question 14

Crude oil comes from different parts of the world and has different _____ characteristics.

Answer 14

physical and chemical

Question 15

crude oil products

Answer 15

• LPG
• Gasoline
• Diesel & Kerosene
• Jet fuel
• lube oil
• asphalt
• petroleum coke

Question 16

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).

Answer 16

Desalting

Question 17

effects of poor desalting

Answer 17

• fouling
• corrosion
• catalyst poison

Question 18

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.

Answer 18

water washing

Question 19

how desalter unit works

Answer 19

• water washing
• heating
• coalescence
• settling

Question 20

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.

Answer 20

heating

Question 21

_____ 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.

Answer 21

coalescence

Question 22

_____ is at the front-end of the refinery, also known as topping unit, or atmospheric distillation unit.

Answer 22

Crude distillation unit (CDU)

Question 23

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).

Answer 23

vacuum distillation unit

Question 24

• 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.

Answer 24

solvent deasphalting (SDA)

Question 25

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.

Answer 25

solvent extraction

Question 26

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’’.

Answer 26

solvent dewaxing