Petrochemical processes involve basic building block processes for manufacturing intermediates and products. Key petrochemical processes include thermal cracking, catalytic cracking, and steam reforming which produce olefins, synthesis gas, and aromatic compounds from petroleum feedstocks like naphtha and gas oil. Thermal cracking uses steam to crack ethane, propane and heavier hydrocarbons to produce ethylene, propylene and other products. Catalytic reforming uses naphtha to produce BTX aromatic compounds. Steam reforming produces a mixture of carbon monoxide and hydrogen from hydrocarbon feeds. Polymerization then links monomer molecules into long chains or networks to form plastics, fibers and other polymer products.

1. PetrochemicalPetrochemical
ProcessesProcesses
22.4.2. DESCRIBE THE BASIC BUILDING BLOCK PROCESSES IN
PETROCHEMICAL TECHNOLOGY
EHTISHAM UL HAQ

2. Petrochemical Feedstocks
 The refinery products are: naphtha; gas oil and
catalytic cracker gases.
 NOTE:
 In oil industry: gasoline fraction
 In petrochemical industry, naphtha is the
petroleum fraction that boils between 20-80o
C.
 Naphtahas: mix of alkanes, cycloalaknes and
aromatic hydrocarbons.
 Gas oils are mix of have the same components
but with higher molecular weights.
 Gas oils are used in place of naphtha as a
feedstocks for ethylene manufacture.

3. The Basic building Block Processes
 In USA, large scale cracking : cracker gases are the
precursors fro production of propylene and butenes.
 In Europe and Japan, small scale cracking: cracker
gases are sources fro ethylene.
 Kerosine: chemical feedstock, manufacture of ethylene
• Petrochemical manufacturing involves building blocks processes for the manufacture of
building blocks and intermediates.
• Petrochemical industry is based on intermediates.
• Known Petrochemical Processes: Thermal cracking; catalytic cracking and steam reforming.

4. The Basic building Block Processes (Cont.)
 Cracking: Steam cracking, Catalytic cracking
for olefins pyrolysis gasoline by product
 Steam reforming and Partial oxidation: Synthesis
gas
 Catalytic Reforming: Aromatic production
 Aromatic conversion processes: Aromatic
production
 Alkylation: Linear alkyl benzene
 OXO Process: Oxo-alcohol
 Polymerisation Process: Polymer, elastomers
and synthetic fibre

5. Thermal Cracking
 Also known as steam cracking, is used for manufacture of
ethylene.
 Feedstocks: ethane, propane, naphtha and gas oils.
 When ethane is cracked  ethylene
 Propane  propene + co-product
 Naphtha and gas oil  propylene, butene, butadiene and
aromatic compounds.
Catalytic reforming
• Used for making BTX.
• Feeedstck: naphtha
Steam reforming
• Used for producing a mix of CO and H2.
• Intermediate for making NH3, CH3OH

6. Petrochemical Process Technology
 Petrochemical processes are normally Continuous
Processes; the raw materials are continuously fed
into the plant so as the products.
 Petrochemical plant would have one or more
reaction systems.
 C6H6 + C2H4  C6H5C2H5  C6H5CH=CH2 + H2

7.  Polymerization is a process of
reacting monomer molecules together in a chemical reaction to
form polymer chains or three-dimensional networks.
 There are many forms of polymerization and different sys
 Usually at least 100 monomer molecules must be combined to
make a product that has certain unique physical properties—
such as elasticity, high tensile strength, or the ability to form fibres
—that differentiate polymers from substances composed of
smaller and simpler molecules; often, many thousands of
monomer units are incorporated in a single molecule of a
polymer.tems exist to categorize them.
 he formation of stable covalent chemical bonds between the
monomers sets polymerization apart from other processes, such
as crystallization, in which large numbers of molecules aggregate
under the influence of weak intermolecular forces.
Polymerization