Oxidized disulfide oil (ODSO) solvent compositions are derived from by-product disulfide oil (DSO) compounds produced as by-products from the generalized mercaptan oxidation (MEROX) processing of a refinery feedstock. The oxidized disulfide oil (ODSO) solvent compositions comprise at least a primary oxidized disulfide oil (ODSO) compound selected from either water soluble or water insoluble oxidized disulfide oil (ODSO) compounds and in some embodiments at least 0.1 ppmw of a secondary oxidized disulfide oil (ODSO) compound that is a water soluble oxidized disulfide oil (ODSO) compound.

Systems and processes are provided to prevent light ends such as methane, ethylene and ethane from building up in an olefin/paraffin separation system that uses a combination of a membrane and distillation column for this separation. In one embodiment a small stripper column is provided downstream from a selective hydrogenation reactor. In the other embodiment, a surge vessel with a receiver is added to the retentate stream of the membrane unit.

Systems and processes are provided to prevent light ends such as methane, ethylene and ethane from building up in an olefin/paraffin separation system that uses a combination of a membrane and distillation column for this separation. In one embodiment a small stripper column is provided downstream from a selective hydrogenation reactor. In the other embodiment, a surge vessel with a receiver is added to the retentate stream of the membrane unit.

Provided is an n-heptane production method including: a step of distilling a feed containing C6, C7, and C8+ hydrocarbon components, removing the C8+ and C6 hydrocarbon components, and separating the C7 hydrocarbon component; a step of adding the separated C7 hydrocarbon component to a hydrogenation apparatus and hydrogenating the separated C7 hydrocarbon component; a step of adding the hydrogenated C7 hydrocarbon component to a simulated moving bed (SMB) apparatus and separating the hydrogenated C7 hydrocarbon component into an extract containing n-heptane and a raffinate containing other components; and a step of distilling the extract and separating the n-heptane in an extract column, wherein a purity of the produced n-heptane is 98 wt % or higher.

A process is provided including subjecting a raw C.sub.5 stream containing C.sub.5 diolefins to extractive distillation to form C.sub.5 diolefins and a raffinate stream. The process includes subjecting the raffinate stream to dehydrogenation to form additional C.sub.5 diolefins, which are recycled to the extractive distillation. Another process includes modifying a C.sub.5 diolefin extractive distillation unit by forming a recycle loop with a C.sub.5 olefin dehydrogenation reactor. A system is provided that includes a C.sub.5 diolefin extractive distillation unit and a C.sub.5 olefin dehydrogenation reactor that are arranged in a recycle loop. A process is provided that includes subjecting a raffinate stream containing C.sub.5 olefins from an extractive distillation unit to dehydrogenation to form C.sub.5 diolefins.

A process is provided including subjecting a raw C.sub.5 stream containing C.sub.5 diolefins to extractive distillation to form C.sub.5 diolefins and a raffinate stream. The process includes subjecting the raffinate stream to dehydrogenation to form additional C.sub.5 diolefins, which are recycled to the extractive distillation. Another process includes modifying a C.sub.5 diolefin extractive distillation unit by forming a recycle loop with a C.sub.5 olefin dehydrogenation reactor. A system is provided that includes a C.sub.5 diolefin extractive distillation unit and a C.sub.5 olefin dehydrogenation reactor that are arranged in a recycle loop. A process is provided that includes subjecting a raffinate stream containing C.sub.5 olefins from an extractive distillation unit to dehydrogenation to form C.sub.5 diolefins.

A method for purification of a styrene-containing feedstock includes steps of introducing the styrene-containing feedstock into the middle of an extractive distillation column, and a solvent for the extractive distillation into the upper part of the column; discharging a raffinate oil from the top of the column, and a rich solvent rich in styrene from the bottom of the column. The rich solvent is then introduced into the middle of the solvent recovery column for vacuum distillation to obtain a crude styrene from the top of the solvent recovery column, and a lean solvent is discharged from the bottom of the solvent recovery column and recycled to the upper part of the extractive distillation column. A portion of the rich solvent is sent to a solvent purification zone for a liquid-liquid extraction using water to obtain a mixture of a styrene polymer and styrene.

A method for purification of a styrene-containing feedstock includes steps of introducing the styrene-containing feedstock into the middle of an extractive distillation column, and a solvent for the extractive distillation into the upper part of the column; discharging a raffinate oil from the top of the column, and a rich solvent rich in styrene from the bottom of the column. The rich solvent is then introduced into the middle of the solvent recovery column for vacuum distillation to obtain a crude styrene from the top of the solvent recovery column, and a lean solvent is discharged from the bottom of the solvent recovery column and recycled to the upper part of the extractive distillation column. A portion of the rich solvent is sent to a solvent purification zone for a liquid-liquid extraction using water to obtain a mixture of a styrene polymer and styrene.

A method for purification of a styrene-containing feedstock includes steps of introducing the styrene-containing feedstock into the middle of an extractive distillation column, and a solvent for the extractive distillation into the upper part of the column; discharging a raffinate oil from the top of the column, and a rich solvent rich in styrene from the bottom of the column. The rich solvent is then introduced into the middle of the solvent recovery column for vacuum distillation to obtain a crude styrene from the top of the solvent recovery column, and a lean solvent is discharged from the bottom of the solvent recovery column and recycled to the upper part of the extractive distillation column. A portion of the rich solvent is sent to a solvent purification zone for a liquid-liquid extraction using water to obtain a mixture of a styrene polymer and styrene.

The invention relates to a process for the preparation of styrene or substituted styrenes comprising the steps of: (a) subjecting a feed containing 1-phenyl ethanol or substituted 1-phenyl ethanol to a dehydration treatment in the presence of a suitable dehydration catalyst; (b) subjecting the resulting product mixture to a separation treatment, thus obtaining a stream containing water and styrene or substituted styrene and a residual fraction containing heavy ends; (c) treating the stream containing water and styrene or substituted styrene with a base; (d) separating the treated stream of step (c) into a styrene or substituted styrene-rich product stream and a styrene or substituted styrene-lean waste water stream; (e) treating the styrene or substituted styrene-lean waste water stream with steam in a stripping column, thus obtaining a treated waste water stream and a treated stream comprising steam and styrene or substituted styrene.