초록 ▼

A process and a system for increasing para-xylene production from a C8 aromatic feedstream by coupling at least one xylene isomerization reactor with at least one pressure swing adsorption unit or temperature swing absorption unit to produce a product having a super-equilibrium para-xylene concentra

A process and a system for increasing para-xylene production from a C8 aromatic feedstream by coupling at least one xylene isomerization reactor with at least one pressure swing adsorption unit or temperature swing absorption unit to produce a product having a super-equilibrium para-xylene concentration. This product is then subjected to para-xylene separation and purification.

대표청구항 ▼

The invention claimed is: 1. A para-xylene production system for producing a para-xylene enriched product, which comprises: at least one xylene isomerization reactor containing an isomerization catalyst and under a hydrogen partial pressure, wherein a feedstream comprises xylenes and ethylbenzene a

The invention claimed is: 1. A para-xylene production system for producing a para-xylene enriched product, which comprises: at least one xylene isomerization reactor containing an isomerization catalyst and under a hydrogen partial pressure, wherein a feedstream comprises xylenes and ethylbenzene and the ethylbenzene is at least partially isomerized and/or at least partially destroyed and the xylenes is isomerized to produce a first product having para-xylene at or near an equilibrium concentration under isomerization conditions; at least one vapor phase swing adsorption unit operating in a cycle to produce from the first product, alternately, a para-xylene depleted product in an adsorption mode and the para-xylene enriched product having a super-equilibrium para-xylene concentration in a desorption mode; and at least one para-xylene recovery unit wherein para-xylene is separated and recovered from the para-xylene enriched product. 2. The system recited in claim 1, wherein said at least one vapor phase swing adsorption unit contains a sorbent. 3. The system recited in claim 2, wherein said sorbent is selected from the group consisting of carbon, a zeolite having a pore diameter of from about 5 Å to about 8.5 Å, and mixtures thereof. 4. The system recited in claim 2, wherein said sorbent comprises ZSM-5, borosilicate, silicalite, SAPO-11, ALPO-11 and mixtures thereof. 5. The system recited in claim 4, wherein said sorbent is ZSM-5. 6. The system recited in claim 1, wherein said at least one vapor phase swing adsorption unit is a pressure swing absorption unit. 7. The system recited in claim 1, wherein said at least one vapor phase swing adsorption unit is a temperature swing absorption unit. 8. A para-xylene production system for producing a para-xylene enriched product, which comprises: at least one first xylene isomerization reactor containing a first catalyst and at a first temperature under a first hydrogen partial pressure, wherein a feedstream comprising xylenes and ethylbenzene is isomerized to produce a first product having para-xylene at or near a first equilibrium concentration under first isomerization conditions; at least one vapor phase swing adsorption unit operating in a cycle to produce from the first product, alternately, a para-xylene depleted product in an adsorption mode and the para-xylene enriched product having a super-equilibrium para-xylene concentration in a desorption mode; at least one second xylene isomerization reactor containing a second catalyst and at a second temperature and under a second hydrogen partial pressure, wherein the second temperature is lower than the first temperature and a second product having para-xylene at or near a second equilibrium concentration under second isomerization conditions from the para-xylene depleted product wherein the second product is sent back to the at least one vapor phase swing adsorption unit; and at least one para-xylene recovery unit wherein para-xylene is separated and recovered from the para-xylene enriched product. 9. The system recited in claim 8, wherein said at least one swing adsorption unit contains a sorbent. 10. The system recited in claim 9, wherein said sorbent is selected form the group consisting of carbon, a zeolite having a pore diameter of from about 5 Å to about 8.5 Å, and mixtures thereof. 11. The system recited in claim 9, wherein said sorbent comprises ZSM-5, borosilicate, silicalite, SAPO-11, ALPO-11 and mixtures thereof. 12. The system recited in claim 11, wherein said sorbent is ZSM-5. 13. The system recited in claim 8, wherein said at least one vapor phase swing adsorption unit is a pressure swing absorption unit. 14. The system recited in claim 8, wherein said at least one vapor phase swing adsorption unit is a temperature swing absorption unit.