A mass transfer assembly has at least one dividing wall, zones of mass transfer structures on opposite sides of the dividing wall, and a vapor flow restrictor that is operable to vary the split of vapor ascending through the zones of mass transfer structures on the opposite sides of the dividing wall.

Embodiments disclosed relate to a debutanizer with a dividing wall. The configuration of the debutanizer includes having a feed section, a top section, a bottom section, and a draw-off section. The debutanizer produces a C4s product, a C5s product and a natural gasoline (NG) product from a C4+s feed. The dividing wall is configured such that an upper portion of the dividing wall is positioned off-set from a vertical centerline and a lower portion of the dividing wall is positioned along the vertical centerline of the debutanizer. A process of use of the debutanizer is also disclosed. A natural gas liquids (NGL) system that includes parallel debutanizers, each with a dividing wall, and a process of use of such system, is also disclosed.

Methods and systems for steam cracking a mixed butane containing feed stream are disclosed. The feed stream includes n-butane and isobutane. The disclosed methods and systems entail splitting the feed into an enriched n-butane fraction and an enriched isobutane fraction. The enriched n-butane fraction is provided to the cracking furnaces, which yield the olefin products and also yield C4 species. The C4 species are partially hydrogenated and provided as a reactant feed to an alkylation reaction. The enriched isobutane fraction is also provided to the alkylation reaction, whereby high value alkylate product is produced. The disclosed methods and systems have increase olefins (especially ethylene) yield because the feed to the cracking process is enriched in n-butane. The economics are also improved because high value alkylate product is produced from a portion of the isobutane.

Enclosed Partition Dividing Wall (EPDW) distillation columns and methods of using EPDW distillation columns are disclosed. The EPDW distillation column includes a column body, a dividing wall, and a wall cap attached to the dividing wall. The wall cap, a portion of column body bound to the wall cap and/or an EPDW surrounding wall, and the dividing wall form an enclosed partition wall rectification section with an opening at the bottom such that a portion of components from the bottom of the column body is separated in the EPDW rectification section.

The selective dimerization of isoolefins, such as isobutene or isopentane, or mixtures thereof, may be conducted in a system including a series of fixed bed reactors and a catalytic distillation reactor. The system may provide for conveyance of the fixed bed reactor effluents, without componential separation, to a downstream reactor. It has been found that a high selectivity to the dimer may be achieved even though intermediate separation of the desired product from unreacted components between reactors is not performed. Further, embodiments provide for use of a divided wall column for recovery of a high purity dimer product, reducing unit piece count and plot size.

The present disclosure relates to a dividing wall distillation column and a method for refining vinylidene dichloride by using the same and, more specifically, to a dividing wall distillation column capable of refining, in a high purity, vinylidene dichloride from a crude product; and a method for refining vinylidene dichloride by using the same. According to the dividing wall distillation column of the present disclosure and the method for refining vinylidene dichloride by using the same, vinylidene dichloride can be refined, in a high purity, from a crude product having a small amount of vinylidene dichloride and a large quantity of high boiling components, and energy consumption can be reduced more than that in conventional cases.

Linear alpha olefins (LAOS) may be formed by oligomerization of ethylene in the presence of a Ziegler-type catalyst. The presence of trace water during oligomerization can result in unwanted formation of insoluble higher oligomers or polymer. Methods for limiting the presence of water during ethylene oligomerization reactions may include separating residual ethylene and 1-butene from an LAO product stream to form a higher LAO-enriched stream comprising C.sub.6+ LAOs, separating 1-hexene as an overhead stream from the higher-LAO enriched stream using a first distillation column, obtaining separated solvent as a side stream from the first distillation column or as a side stream from a first of one or more downstream distillation columns, and returning the separated solvent to a reactor in a recycled solvent stream. The recycled solvent stream passes through one or more driers before returning to the reactor.

The invention is directed to a combined naphtha hydrotreating (NHT) and isomerization process scheme, which includes dividing wall columns (DWC) that replace multiple distillation columns and allow optimized heat integration within the system. The disclosed design provides reductions in both capital and energy costs compared to conventional schemes.

A process for preparing a purified benzene composition from a crude hydrocarbon stream containing at least 10% by volume of benzene is provided. The process comprises subjecting the crude hydrocarbon stream and a further recycled benzene containing stream to a solvent-based extraction so as to produce a benzene enriched aromatic stream and a benzene depleted non-aromatic stream, subjecting the benzene enriched aromatic stream to a hydrodesulfurization so as to obtain a desulfurized aromatic stream, subjecting the desulfurized aromatic stream to a distillation producing a purified benzene stream and a further benzene containing stream having a benzene concentration of between less than 100% by weight and the azeotropic benzene concentration, and at least partially recycling the further benzene containing stream.

An apparatus for a dividing wall column in an isomerization unit is disclosed. The apparatus includes a at least one primary vertical wall located at a first set of predetermined plurality of trays and configured to separate a feed from a first side cut; one or more walls placed at a second set of predetermined plurality of trays and configured to enable a second side cut wherein each of the one or more walls includes at least one predetermined shape, wherein the dividing wall column produces four cuts wherein one is hexane cut, wherein there are two walls in different sections of the column. The at least one primary vertical wall includes one of a straight wall, an ‘L’ shaped wall, an ‘Γ’ shaped wall, or a zig-zag wall. The one or more walls are mechanically coupled to form a second vertical wall.