Device and process for converting a feedstock of aromatic compounds, in which the feedstock is notably treated using a fractionation train (4-7), a xylenes separating unit (10) and an isomerization unit (11), and in which a pyrolysis unit (13) treats a second hydrocarbon-based feedstock, produces a pyrolysis effluent feeding the feedstock, and produces a pyrolysis gas comprising CO, CO2 and H2; an RWGS reverse water gas shift reaction section (51) treats the pyrolysis gas and produces an RWGS gas enriched in CO and in water; a fermentation reaction section (52) treats the RWGS gas enriched in CO and in water and produces ethanol; and an aromatization reaction section (14) converts the ethanol into a mixture of aromatic and paraffinic compounds feeding the feedstock.

Processes for converting C8 aromatic hydrocarbons. In some embodiments, a process for converting a hydrocarbon feed that can include C8 aromatic hydrocarbons can include feeding the hydrocarbon feed into a conversion zone and contacting the hydrocarbon feed at least partly in a liquid phase with an isomerization catalyst composition in the conversion zone under conversion conditions to effect isomerization of at least a portion of the C8 aromatic hydrocarbons to produce a conversion product rich in para-xylene. In some embodiments, the isomerization catalyst composition can include a zeolite (preferably a ZSM-5 zeolite) that can have a silica (SiO.sub.2) to alumina (AI.sub.2O.sub.3) molar ratio of 10 to 100, a total surface area of 200 m.sup.2/g to 700 m.sup.2/g, a micropore surface area of 50 m.sup.2/g to 600 m.sup.2/g, and an external surface area of 55 m.sup.2/g to 550 m.sup.2/g.

Processes for converting C8 aromatic hydrocarbons. In some embodiments, a process for converting a hydrocarbon feed that can include C8 aromatic hydrocarbons can include feeding the hydrocarbon feed into a conversion zone and contacting the hydrocarbon feed at least partly in a liquid phase with an isomerization catalyst composition in the conversion zone under conversion conditions to effect isomerization of at least a portion of the C8 aromatic hydrocarbons to produce a conversion product rich in para-xylene. In some embodiments, the isomerization catalyst composition can include a zeolite (preferably a ZSM-5 zeolite) that can have a silica (SiO.sub.2) to alumina (AI.sub.2O.sub.3) molar ratio of 10 to 100, a total surface area of 200 m.sup.2/g to 700 m.sup.2/g, a micropore surface area of 50 m.sup.2/g to 600 m.sup.2/g, and an external surface area of 55 m.sup.2/g to 550 m.sup.2/g.

Methods of converting isobutylene to C5+ compounds. The methods may include contacting isobutylene with a skeletal isomerization catalyst to provide a mixture of C.sub.4 olefins, and then contacting the mixture of C.sub.4 olefins with a metathesis catalyst to convert the mixture of C.sub.4 olefins to a product mixture. The product mixture may include C.sub.5+ olefins.

The invention is directed to a process to prepare propylene from a hydrocarbon feed comprising pentane by contacting the hydrocarbon feed with a heterogeneous cracking catalyst as present in one or more fixed beds thereby obtaining a cracked effluent. The heterogeneous catalyst comprises a matrix component and a molecular sieve comprising framework alumina, framework silica and a framework metal selected from the group of Zn, Fe, Ce, La, Y, Ga and/or Zr. Propylene is isolated from the cracked effluent.

An changeable lead-lag configuration of two isomerization reactors can be used to achieve continuous isomerization operations in an aromatics production complex, even if the isomerization catalyst deactivates over time to require catalyst regeneration and/or replacement. The configuration can be particularly advantageous for two liquid phase isomerization reactors, especially those operated under a high WHSV≥5 hour.sup.−1 where the isomerization catalyst can deactivate at a high rate.

An changeable lead-lag configuration of two isomerization reactors can be used to achieve continuous isomerization operations in an aromatics production complex, even if the isomerization catalyst deactivates over time to require catalyst regeneration and/or replacement. The configuration can be particularly advantageous for two liquid phase isomerization reactors, especially those operated under a high WHSV≥5 hour.sup.−1 where the isomerization catalyst can deactivate at a high rate.

A liquid phase isomerization process comprising cofeeding molecular hydrogen at a feeding rate ≥100 ppm by weight can effectively convert a C8 aromatic hydrocarbon isomerization feed in the presence of an isomerization catalyst with a very low deactivation rate of the catalyst, even at high WHSV ≥5 hour.sup.−1.

A liquid phase isomerization process comprising cofeeding molecular hydrogen at a feeding rate ≥100 ppm by weight can effectively convert a C8 aromatic hydrocarbon isomerization feed in the presence of an isomerization catalyst with a very low deactivation rate of the catalyst, even at high WHSV ≥5 hour.sup.−1.

A skeletal isomerization process for isomerizing olefins is described. The process includes the steps of feeding an olefin-containing feed to a reactor at a space velocity of 1-100 hr.sup.−1 for a first period of time at a first temperature, followed by discontinuing, or stopping, the olefin-containing feed for a second period of time while maintaining the reactor at a second temperature, before resuming the flow of the olefin-containing feed for a third period of time. The methods of this disclosure increase the yield of the skeletal isomers product while reducing the production of C5+ heavy olefins. Additionally, the methods of this disclosure can be applied to feeds containing iso-olefins (for the production of linear olefins) or linear olefins (for the production of iso-olefins).