Upgrading light naphtas for increased olefins production

Process to upgrade light naphthas comprising branched paraffins and their use as a feedstock in a steam cracking unit, said light naphthas consisting essentially of 90 to 100% by weight of hydrocarbons having at least 5 and up to 8 carbon atoms, said process comprising,

• a) providing an isomerization zone recovered from the gasoline unit of an oil refinery,
• b) providing a separation zone capable to treat an hydrocarbon stream comprising branched paraffins and normal paraffins to produce a first hydrocarbon stream having a reduced branched paraffins content and an enhanced normal paraffins content and a second hydrocarbon stream having an enhanced branched paraffins content and a reduced normal paraffins content,
• c) sending the light naphtha to the separation zone to recover a first and a second hydrocarbon streams,
• d) sending the second hydrocarbon stream recovered from step c) to the isomerization zone and operating said zone at conditions effective to produce a light naphtha having a reduced branched paraffins content and an enhanced normal paraffins content,
• e) mixing the outlet stream of step d) with the first hydrocarbon stream recovered from step c) and sending said mixed stream to the steam cracking unit.

Process to upgrade light naphthas comprising branched paraffins and their use as a feedstock in a steam cracking unit, said light naphthas consisting essentially of 90 to 100% by weight of hydrocarbons having at least 5 and up to 8 carbon atoms, said process comprising,

• a) providing an isomerization zone recovered from the gasoline unit of an oil refinery,
• b) providing a separation zone capable to treat an hydrocarbon stream comprising branched paraffins and normal paraffins to produce a first hydrocarbon stream having a reduced branched paraffins content and an enhanced normal paraffins content and a second hydrocarbon stream having an enhanced branched paraffins content and a reduced normal paraffins content,
• c) optionally providing a depentanizer,
• d) sending the light naphtha to the separation zone to recover a first and a second hydrocarbon streams,
• e) sending the first hydrocarbon stream recovered from step d) to the steam cracking unit,
• f) sending at least a part of the second hydrocarbon stream recovered from step d) to the isomerization zone and operating said zone at conditions effective to produce a light naphtha having a reduced branched paraffins content and an enhanced normal paraffins content,
• g) optionally, before sending the second hydrocarbon recovered from step h) to the isomerization zone, sending said hydrocarbon stream to a depentanizer to recover a stream comprising essentially pentane and a stream having a reduced pentane content and sending said stream comprising essentially isopentane to the isomerization zone,
• i) recycling the outlet stream from step f) to the inlet of the separation zone.

Process to upgrade light naphthas comprising branched paraffins and their use as a feedstock in a steam cracking unit, said light naphthas consisting essentially of 90 to 100% by weight of hydrocarbons having at least 5 and up to 8 carbon atoms, said process comprising,

• a) providing an isomerization zone recovered from the gasoline unit of an oil refinery,
• b) providing a deisopentanizer,
• c) sending the light naphtha to a deisopentanizer to recover a stream comprising essentially isopentane and a stream having a reduced isopentane content,
• d) sending the stream having a reduced isopentane content recovered from step c) to the steam cracking unit,
• e) sending the stream comprising essentially isopentane recovered from step c) to the isomerization zone and operating said zone at conditions effective to produce a light naphtha having a reduced branched paraffins content and an enhanced normal paraffins content,
• f) recycling the outlet of step e) to the inlet of the deisopentanizer.