C2 - refining of crude oils

Question 1

What does refinning mean?

Answer 1

converting complex mixtures of HC into complex mix of HC that meet specifications

Question 2

4 main steps of refinning

Answer 2

raw material –> fractionation/seperation –> conversion (decomp/reforming) –> blending (=meet specifications) –> Products

Question 3

5 crude oils

Answer 3

PIONA
parafines
isoparafins
olefins
naphtene
aromatics

Question 4

is the elementary composition = chemical composition

Answer 4

NO

Question 5

Describe what elementary composition is

Answer 5

its constant
C, H, N, O, S

Question 6

Describe what chemical composition is

Answer 6

its a fonction of (time, T, P, depth, location)
–> it differs

Question 7

What is fractionation

Answer 7

seperation of products

Question 8

What is conversion, name 3 exemples

Answer 8

Carcking (long chains –> small chains)
Recombination (make longer chains)
Reforming

Question 9

Name 2 exemples of cracking

Answer 9

Steam reforming
FCC (catalyst)

Question 10

What is blending

Answer 10

to meet the requirements

Question 11

Name 4 requirements for gasoline + why

Answer 11

Sulfur content –> acid rains
Aromatics –> soute during combustion
Nitrogen –> conversion of NOx needs cat
Octane # (ON) –> quality factor, don’t want detonation

Question 12

Explain the 4 steps of a gasoline engine

Answer 12

ignition induced by spark plug

1. piston down, air fuel in
2. Piston up, compression, air/gasoline mix = T rises
3. Spark plug = fuel ignition, piston forced down
4. Escape

Question 13

Escape diesel 3 step engine

Answer 13

Cetane #, fuel directly injected = self ignition

1. Air only, piston down
2. piston up, no ignition bc no fuel
3. add fuel to compressed air = quick ignition

Question 14

What are 2 quality characteristics of crude oil

Answer 14

1. Density (low/light, API >10) = floats
2. Sulfur content (sweet = :), sour = bad, too much S)

we want light and sweet = cheaper to produce

Question 15

classer en ordre du plus simple au plus complex les types de refineries (Nelson complexity index)

Answer 15

Topping < Hydroskimming < conversion cracker < deep conversion cocker

Question 16

What is the first step for any refinery?

Answer 16

Desalting of crude oils

Question 17

Explain what desalting of crude oils does.

Answer 17

Avoid corrosion, deposit formation, scaing, catalyst poisonning

use an electrostatic / decantation –> based on solubility gradient with hot water

Question 18

What is a topping refinnery, what are the steps?

Answer 18

is a simple atm crude distillator, only for industrial applications

1. desalting of crude oils
2. atmospheric distillation
3. aromatic fractionator
4. 2x strippers

Question 19

What is the feed of the strippers in a topping refinery?

Answer 19

steam –> seperation by boiling point

Question 20

What is the max T in topping refinery, why?

Answer 20

620K if higher = cracking and degradation –> forms coke

(350-400°C)