Process and device for the inverted separation of aromatics
AssigneeAxens
InventorsJérôme Pigourier, Isabelle Prevost
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Abstract
The present invention relates to a process and to a device for the separation of a feedstock comprising benzene, toluene and C8+ compounds, in which: a toluene column (C10) is fed directly with a C7+ cut resulting from the bottom of a stabilization column (C11) positioned downstream of a transalkylation unit (P4); a C7− cut is withdrawn at the top of the toluene column (C10) and a C8+ cut is withdrawn at the bottom; a benzene column (C9) is fed with the C7− cut resulting from the toluene column (C10); an essentially aromatic cut resulting from an aromatics extraction unit (P1) is injected into the toluene column (C10) separately above the feeding of the C7+ cut or into the benzene column (C9).
Claims21
Process for the separation of a feedstock comprising benzene, toluene and compounds having 8 or more carbon atoms, in a separation device comprising at least one reformate column (C1), one aromatics extraction unit (P1) and one transalkylation unit (P4), the effluents from the units being separated in the following distillation columns:
- benzene column (C9), toluene column (C10) and stabilization column (C11), the process comprising the following stages:
- feeding the toluene column (C10) directly with a C7+ cut recovered from the bottom of the stabilization column (C11) positioned downstream of the transalkylation unit (P4) and withdrawing a top product from the toluene column (C10) enriched in benzene and in toluene and a bottom product from the toluene column (C10) enriched in compounds having 8 or more carbon atoms,
- feeding the benzene column (C9) with the top product from the toluene column (C10) and withdrawing a benzene-enriched top product from the benzene column (C9) and a toluene-enriched bottom product from the benzene column (C9), and
- feeding the transalkylation unit (P4) with the toluene-enriched bottom product from the benzene column (C9), and further comprising
- in addition to feeding the toluene column (C10) directly with a C7+ cut recovered from the bottom of the stabilization column (C11) positioned downstream of the transalkylation unit (P4), separately feeding the toluene column (C10) with an essentially aromatic cut resulting from the aromatics extraction unit (P1) to a position above a position at which the toluene column (C10) is fed with the C7+ cut recovered from the bottom of the stabilization column (C11), or
- feeding the benzene column (C9) with the essentially aromatic cut resulting from the aromatics extraction unit (P1) as a mixture with or separately from the top product from the toluene column (C10).
Device for the separation of a feedstock comprising benzene, toluene and compounds having 8 or more carbon atoms, the separation device comprising at least one reformate column (C1), one aromatics extraction unit (P1) and one transalkylation unit (P4), the separation device additionally comprising the following columns for the distillation of the effluents from the units:
- benzene column (C9), toluene column (C10) and stabilization column (C11),
- the toluene column (C10) being configured to receive a C7+ cut recovered from the bottom of the stabilization column (C11) positioned downstream of the transalkylation unit (P4) and to deliver a top product from the toluene column (C10) enriched in benzene and in toluene and a bottom product from the toluene column (C10) enriched in compounds having 8 or more carbon atoms,
- the benzene column (C9) being configured to receive the top product from the toluene column (C10) and to deliver a benzene-enriched top product from the benzene column (C9) and a toluene-enriched bottom product from the benzene column (C9), and
- the transalkylation unit (P4) being configured to treat the toluene-enriched bottom product from the benzene column (C9), wherein:
- in addition to the toluene column (C10) being configured to receive a C7+ cut resulting from the bottom of the stabilization column (C11), the toluene column (C10) is also configured to separately receive an essentially aromatic cut resulting from the aromatics extraction unit (P1) at a position above a position at which the toluene column (C10) receives the C7+ cut recovered from the bottom of the stabilization column (C11), or wherein
- the benzene column (C9) is configured to receive the essentially aromatic cut resulting from the aromatics extraction unit (P1) as a mixture with or separately from the top product from the toluene column (C10).
Dependencies are inferred from the claim text.