Major Refining Process

Petrochemical & Petroleum
Refining Technology

Major Refining Process

Crude Processing

Definition:
• Separating crude oil into different hydrocarbon group
• The most common methods is through distillation.

1. Desalting: Crude oil is desalted to remove corrosive salts as well as
metals and other supsended solids.

2. Atmospheric Distillation: Used to separate the desalted crude into
specific hydrocarbon group.

3. Vacuum Distilation: Heavy crude residue from atmospheric
distillation is further separated using lower-pressure distillation
process.



Cracking

Definition:
• Breaking down large, heavy hydrocarbon molecules into smaller

molecules through application of heat or catalyst.

1. Coker: Thermal non-catalytic cracking process that converts low
value oils to higher value gasoline, gas oils and marketable coke.

2. Visbreaking: Thermal non-catalytic process used to convert large
hydrocarbon molecules in heavy feedstocks to lighter products
such as fuel gas, gasoline, naphtha and gas oil.

3. Catalytic Cracking: Heavy gas oil and large molecules are crack into
smaller molecules (gasoline, lighter boiling range) with presence of
catalyst.

4. Catalytic Hydrocracking: Induction of hydrogen to a catalyst allows
the cracking reaction to proceed at lower temperature than in
catalytic cracking, athough pressure are much higher.



Combination

Definition:
• Linking two or more hydrocarbon molecules together to form a large

molecules (eg converting gases to liquids) or rearranging to improve
the quality of the molecules.

1. Alkylation: Process to upgrade light olefins to high-value gasoline
components. Used to combine small molecules into large
molecules to produce higher octane product for blending into
gasoline.

2. Catalytic reforming: The process of chaning napthha chemically to
increase octane numbers.

3. Polymerization: Process that combine smaller molecules to
produce high octane blendstocks.

4. Isomerization: Process used to produce compounds with high
octane for blending into gasoline pool. Also used to produce
isobutene-important feedstock for alkylation.

Treating

Definition:
• Processing of petroleum products to remove some of sulfur, nitrogen,

heavy metal and other impurities.

1. Cataltic Hydrotreating, Hydroprocessing, sulfur/metals removal:
Used to remove imurities (eg sulfur, nitrogen, oxygen, halides)
from petroleum fractions.

2. Hydrotreating: upgrades heavy feeds by converting olefins and
diolefins to paraffins.

3. Hydroprocessing: cracks heavier products to lighter products.