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US 2020/0002252 A1Published application
Process for producing para-xylene using a step in a simulated moving bed and a step of fractionation via a three-fraction column
AssigneeAxens
InventorsIsabelle PREVOST, Jerome PIGOURIER, Pierre-Yves MARTIN, Arnaud COTTE
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Abstract
The present invention relates to a process for producing high-purity para-xylene, comprising a single step of separation by adsorption in an SMB, with a subsequent step of separation by distillation in a first three-fraction distillation column producing at least two raffinates and optionally of two isomerization steps, making it possible to improve the overall para-xylene yield of the aromatic loop and to minimize the economic impact.
Claims15
Process for producing para-xylene from a feedstock containing xylenes, ethylbenzene and C9+ hydrocarbons, comprising
- a single step A of separation in a simulated moving bed of said feedstock performed with a zeolite as adsorbent and a desorbent, at a temperature of between 20 and 250° C., at a pressure of between 1.0 and 2.2 MPa, and with a volume ratio of the desorbent to the feedstock in the simulated moving bed separation unit of between 0.4 and 2.5;
- said step A allowing the production of
- a first fraction (A1) containing a mixture of para-xylene and of desorbent, and
- at least one second fraction (A2 or A21) containing ethylbenzene (EB), ortho-xylene (OX) and meta-xylene (MX) and desorbent,
- a step B of fractionation by distillation in at least one first distillation column (B_C3) of said second fraction derived from step A, allowing the production of three fractions:
- a first fraction (B2) containing EB, OX and MX,
- a second fraction (B3) containing OX and MX, and
- a third fraction (B42) containing desorbent.
5 more elements
Dependencies are inferred from the claim text.