The present invention relates to an improved extractive distillation process for recovering aromatic hydrocarbons from non-aromatic hydrocarbons in naphtha streams containing heavy hydrocarbon contaminants wherein each contaminant is characterized as having a boiling point in the range of between that of the separated non-aromatic hydrocarbons and the extractive distillation solvent utilized to recover and purify the aromatic hydrocarbons.

An improved hydrotreating catalyst and process for making a base oil product wherein the catalyst comprises a base extrudate that includes a high nanopore volume amorphous silica alumina (ASA) and an alumina. The catalyst and process generally involve the use of a high nanopore volume ASA/alumina based catalyst to produce hydrotreated dewaxed base oil products by contacting the catalyst with a hydrocarbon feedstock. The catalyst base extrudate advantageously comprises an amorphous silica alumina having a pore volume in the 11-20 nm pore diameter range of 0.2 to 0.9 cc/g and an alumina having, a pore volume in the 11-20 nm pore diameter range of 0.01 to 1.0 cc/g, with the base extrudate formed from the amorphous silica alumina and the alumina having a total pore volume in the 2-50 nm pore diameter range of 0.12 to 1.80 cc/g. The catalyst further comprises at least one modifier element from Groups 6 to 10 and Group 14 of the Periodic Table. The catalyst and process provide improved aromatics saturation.

Processes and apparatuses for isomerizing hydrocarbons are provided. In an embodiment, a process for isomerizing hydrocarbons includes providing a first hydrocarbon feed that includes hydrocarbons having from 5 to 7 carbon atoms. The first hydrocarbon feed is fractionated to produce a first separated stream that includes hydrocarbons having from 5 to 6 carbon atoms and a second separated stream that includes hydrocarbons having 7 carbon atoms. The first separated stream is contacted with a benzene saturation catalyst at benzene saturation conditions to produce an intermediate stream and subsequently isomerized in the presence of a first isomerization catalyst and hydrogen under first isomerization conditions to produce a first isomerized stream. The second separated stream is isomerized in the presence of a second isomerization catalyst and hydrogen under second isomerization conditions that are different from the first isomerization conditions to produce a second isomerized stream.

Processes and apparatuses for isomerizing hydrocarbons are provided. In an embodiment, a process for isomerizing hydrocarbons includes providing a first hydrocarbon feed that includes hydrocarbons having from 5 to 7 carbon atoms. The first hydrocarbon feed is fractionated to produce a first separated stream that includes hydrocarbons having from 5 to 6 carbon atoms and a second separated stream that includes hydrocarbons having 7 carbon atoms. The first separated stream is contacted with a benzene saturation catalyst at benzene saturation conditions to produce an intermediate stream and subsequently isomerized in the presence of a first isomerization catalyst and hydrogen under first isomerization conditions to produce a first isomerized stream. The second separated stream is isomerized in the presence of a second isomerization catalyst and hydrogen under second isomerization conditions that are different from the first isomerization conditions to produce a second isomerized stream.

A process and a system are used for production of multiple grades of ultralow aromatic solvents/chemicals having preferred boiling range, flash point and viscosity from different hydrocarbon streams. A plurality of hydrotreating steps are used to hydrotreat a plurality of hydrocarbon feedstocks in the presence of a hydrogen gas stream and a catalyst system. Further, at least one dissolved gas stripping step, at least one adsorption step, and a distillation step are included in the process. Desired iso-paraffin molecules are thereby preserved, and the undesired aromatic molecules are converted into desired naphthene molecules.

Processes for hydrotreating a hydrocarbon stream in which a separation zone and a stripping zone is disposed between two hydrotreating reactors. The stripping zone may comprise a portion of the second hydrotreating reactor. The separation zone may comprise two separator vessels. A separator vessel may include the scrubbing zone to receive a scrubbing fluid, for example, steam, hydrogen, or heated effluent, and remove H.sub.2S and NH.sub.3. A divided wall separator may be used. Vapor from the separator vessels can be recycled in the system.

Processes for hydrotreating a hydrocarbon stream in which a separation zone and a stripping zone is disposed between two hydrotreating reactors. The stripping zone may comprise a portion of the second hydrotreating reactor. The separation zone may comprise two separator vessels. A separator vessel may include the scrubbing zone to receive a scrubbing fluid, for example, steam, hydrogen, or heated effluent, and remove H.sub.2S and NH.sub.3. A divided wall separator may be used. Vapor from the separator vessels can be recycled in the system.

A process for the continuous dearomatization of a petroleum cut to produce a hydrocarbon-containing fluid with a very low sulphur content and very low aromatic compounds content, includes at least one stage of catalytic hydrogenation at a temperature between 80 and 180 C. and at a pressure between 50 and 160 bar. The stage of catalytic hydrogenation of the dearomatization process comprises several interchangeable reactors linked in series.

A process for the continuous dearomatization of a petroleum cut to produce a hydrocarbon-containing fluid with a very low sulphur content and very low aromatic compounds content, includes at least one stage of catalytic hydrogenation at a temperature between 80 and 180 C. and at a pressure between 50 and 160 bar. The stage of catalytic hydrogenation of the dearomatization process comprises several interchangeable reactors linked in series.

Methods are provided for modifying hydrogenation catalysts having silica supports (or other non-alumina supports) with additional alumina, and using such catalysts to achieve unexpectedly superior hydrogenation of feedstocks. The modified hydrogenation catalysts can have a relatively low cracking activity while providing an increased activity for hydrogenation.