310204i Production and Processing Plants

Question 1

Define cracking

Answer 1

Cracking is the process of breaking hydrocarbon molecules into smaller molecules

Question 2

What is an Olegin Gas?

Answer 2

Gases such as Ethene and Ethylene that are used for the manufacture of other chemicals

Question 3

Define Coke, as it relates to the refinery process

Answer 3

A carbon-based solid that can be used as heating fuel in the metals and ceramic industries and for the production of graphite electrodes use in electric arc furnaces
It is a byproduct of the coking process

Question 4

What is Naphtha?

Answer 4

A flammable liquid mixture of similar hydrocarbons from C5 to C12
Naphtha is used as feedstock for producing high-octane gas, and in other commercial uses.

Question 6

Name the type of solvent that is widely used for acid gas removal.

Answer 6

Amine solvents

Question 7

Which process converts hydrogen sulfide (H2S) to elemental sulfur in one step?

Answer 7

The Sulferox Process

H2S comes into contact with an iron solution in a contactor and the reaction produces elemental sulfur

Question 8

Which gas sweetening method does not use an H2S solvent

Answer 8

Molecular Sieve gas sweetening

A column containing adsorbent material that selectively adsorbs mercaptans and acid gases while allowing purified hydrocarbons to pass through

Question 9

Define adsorption

Answer 9

Adsorption is when atoms, ions, or molecules from a substance adhere to a surface of the adsorbent

Question 10

What is the purpose of the Claus process

Answer 10

Extracts elemental sulfur from hydrogen sulfide (sour gas)

Question 11

What happens to the Claus unit tailgas so it can be treated with amine solvent?

Answer 11

The sulfur in the tailgas is converted back to hydrogen sulfide

Question 12

What are the 4 hydrocarbons that make up the bulk of natural gas?

Answer 12

1. Methane CH4
2. Ethane C2H6
3. Propane C3H8
4. Butane C4H10

Question 13

Which hydrocarbon in natural gas is fuel gas?

Answer 13

Methane CH4

Question 15

In modern gas plants, what type of equipment is used for natural gas liquid (NGL) extraction?

Answer 15

Cryogenic equipment

Question 16

Why are the components of natural gas referred to as liquids or gas liquids?

Answer 16

Because at underground pressures, they are liquids, but at atmospheric pressures, they convert to gases

Question 17

What are the 2 methods used to remove water from the gas stream?

Answer 17

1. Glycol dehydration - lean glycol and wet gas are fed into a high pressure contractor where the glycol absorbs water from the gas
2. Temperature swing adsorption - wet gas passes through columns filled with adsorbent material called a dessicant. The dessicant absorbs the water while letting the gas pass through. Heated dry purge gas drives the moisture out and regenerates the column.

Question 18

Why must the catalyst be regenerated in a fluid catalytic cracking (FCC) process?

Answer 18

The shortage of hydrogen atoms in the process results in the formation of Coke, which covers the catalyst. The catalyst must then be removed

Question 19

Why is vacuum fractionation used in refineries?

Answer 19

The process uses lower temperatures, which prevents thermal cracking.

Question 20

What type of cracking does a visbreaking process perform?

Answer 20

Mild form of thermocracking

Question 21

Name three primary treatments used in heavy oil upgraders.

Answer 21

1. Thermal conversion - carbon rejection process, bitumen or feed is heated and cracked hydrocarbons exit the coker (delayed coker or fluid coker) as gas vapours
2. Hydroconversion - hydrogen addition process, heavy feedstock is cracked in the presence of hydrogen, takes place under high pressure and temperature within an ebullated bed hydrocracker
3. Thermal cracking - thermic method to break larger molecules into smaller one, high pressures, generated syn gas which is used to generate steam for SAGD extraction

Question 22

How are oil upgraders distinguished from each other?

Answer 22

By the primary method of treatment

Question 23

What byproduct is produced by a carbon rejection cracking process?

Answer 23

Coke

Question 24

Which upgrader type uses hydrogen addition cracking

Answer 24

Hydroconversion

Question 25

What are the 3 main components of wood?

Answer 25

1. Cellulose fibres
2. Lignin
3. Hemicellulose

Question 26

What are the 2 sections of a pulp mill?

Answer 26

1. Pulp manufacturing units
2. Recovery units

Question 27

What is the name given to the solvent that breaks down the lignin in wood?

Answer 27

White liquor

White liquor is a solution made up of sodium hydroxide (NaOH) and soldium sulphide

Question 28

What are the 2 purposes for a recovery boiler?

Answer 28

1. To recover processing chemicals
2. To generate steam

Question 29

Why are wood chips pretreated with steam before they are fed into the digester?

Answer 29

Pre treating with steam removes air from the chips and enhances liquor absorption

Question 30

Which unit in a pulp manufacturing facility produces wood fibers? Explain how the fibers are made.

Answer 30

Wood fibers are produced in blowtank
The sudden change in pressure creates expanding vapors that blow the wood chips apart into fibers.