WEEK 4: Petrochemicals – Naphtha Cracking Flashcards
(21 cards)
_____ are chemicals derived from petroleum
products.
Petrochemicals
Examples of petrochemicals
plastics, rubbers, fibers, paints, solvents, and detergents
what is the largest petrochemical plant in the country?
JG Summit Olefins Corporation
(JGSOC)
what are the two subsidiaries before the JGSOC have emerged
- JG Summit Petrochemical Corporation
- JG Summit Olefins Corporation
_____ is a mixture of hydrocarbons boiling in the range of the lowest boiling component (C5) to 150°C, which contains paraffins, naphthenes, and aromatics in various proportions.
Naphtha
It is found that paraffins yield _____ when heated at a high
temperature.
olefins
Naphtha cracking is carried out in a tube-still furnace at a
temperature above _____
800°C
If the reaction is continued indefinitely (the nature of naphtha cracking), branched and cyclized heavy hydrocarbons will be produced and _____ will be generated as the ultimate product.
coke
_____ is introduced with the feed to remove the coke layer on the tube surface by converting coke into carbon monoxide and hydrogen by water gas reaction
Steam
what are the by-products of cracking
propylene, butylene, butadiene, and aromatics, such as benzene, toluene, xylene, isomeric paraffins, naphthenic components, and polynuclear aromatics.
_____ are separated in a fractionating column the bottom product of which is the heavy cracked oil rich in high boiling aromatics.
Cracked liquids and gases
_____ is also partly used as the quenching medium for the products from the furnace and partly sold as the carbon black feedstock (CBFS) due to its heavy aromatic contents.
heavy oil
Cracked gases containing hydrocarbons, both saturated and unsaturated, from methane to C7 hydrocarbons emerge from the top of the column, which is then compressed and amine (or caustic) washed to remove _____
hydrogen sulfide and carbon dioxide gases
Amine or caustic washed gases are then passed through a flash separator vessel, where liquid hydrocarbon gases are separated from hydrogen at high pressure and low temperature.
Hydrogen Separator
_____ from hydrogen separator is used in the hydrogenating units, such as pyrolysis gasoline and butadiene hydrogenation, or as a fuel.
Hydrogen
Liquified gases from a hydrogen separator are then separated from methane in a distillation column where methane (C1) emerges from the top and is used as a fuel for the cracking furnace. The bottom of the column is then passed to a de-ethaniser.
Demethaniser
It is also a distillation column that separates ethane and ethylene mixture (C2 mixture) as the top product from the rest of the liquified gases containing propane, propylene, butane, butylenes, etc.
De-ethaniser
A C2 mixture from the top of the de-ethaniser column is then passed through another distillation column that separates ethylene as the top product and ethane as the bottom product. Ethylene is sent to storage and is used up in the polyethylene (PE) synthesis plant. Ethane from this column is recycled to a small cracking furnace to yield additional ethylene.
Ethane-ethylene separator
The liquified gas mixture from the bottom of the de-ethaniser is separated from propane and propylene (C3 mixture), which leaves from the top of the column and enters the propane–propylene fractionator. The bottom product contains the butanes, butenes, butadiene, and heavier components, which are then separated from the butane–butene mixture (C4 mixture).
Depropaniser
In this column, propylene is recovered as the top product and propane as the bottom product. Propylene is stored and used for manufacturing polypropylene, and propane is sold as a domestic fuel—liquified petroleum gas (LPG).
Propane–propylene separator
Butane, butenes, and butadiene (C4 mixture) are recovered as the top product and components heavier than the C4 mixture, i.e., C5 and heavier, are recovered as the pyrolysis gasoline (bottom product). Pyrolysis gasoline is catalytically hydrodesulfurised before it is sold or blended as a gasoline component.
Debutaniser
