Recovery of aliphatic hydrocarbons

A process for steam cracking a hydrocarbon feed, the process comprising:

• recovering aliphatic hydrocarbons from a liquid hydrocarbon feedstock stream to produce recovered aliphatic hydrocarbons, wherein the liquid hydrocarbon feedstock stream comprises a liquid product produced by pyrolysis of plastic waste;
• and
• steam cracking a hydrocarbon feed which comprises the recovered aliphatic hydrocarbons,
• wherein the liquid hydrocarbon feedstock stream comprises aliphatic hydrocarbons, polar components and optionally aromatic hydrocarbons,
• wherein the aliphatic hydrocarbons comprise paraffinic and olefinic aliphatic hydrocarbons,
• wherein the polar components comprise heteroatom containing organic compounds and optionally salts,
• wherein the heteroatom containing organic compounds contain one or more heteroatoms and comprise oxygen containing organic compounds, nitrogen containing organic compounds and halogen containing organic compounds, and
• wherein the amount of the polar components is at least 0.5 wt. % and the amount of the optional aromatic hydrocarbons is at most 20 wt. %,
• wherein recovering aliphatic hydrocarbons from the liquid hydrocarbon feedstock stream comprises the steps of:
• feeding the liquid hydrocarbon feedstock stream to a first column;
• feeding a first solvent stream which comprises an organic solvent to the first column at a position which is higher than the position at which the liquid hydrocarbon feedstock stream is fed, wherein the organic solvent in the first solvent stream contains one or more heteroatoms;
• contacting at least a portion of the liquid hydrocarbon feedstock stream with at least a portion of the first solvent stream;
• and
• recovering at least a portion of the aliphatic hydrocarbons by liquid-liquid extraction of the polar components and optionally the aromatic hydrocarbons with the organic solvent,
• resulting in a top stream from the first column comprising the recovered aliphatic hydrocarbons and a first portion of the organic solvent and a bottom stream from the first column comprising a second portion of the organic solvent, the polar components, and optionally the aromatic hydrocarbons;
• feeding the top stream from the first column to a second column;
• feeding a second solvent stream which comprises water to the second column at a position which is higher than the position at which the top stream from the first column is fed;
• contacting at least a portion of the top stream from the first column with at least a portion of the second solvent stream;
• and
• removing at least a portion of the organic solvent from the top stream from the first column by liquid-liquid extraction of the organic solvent with water,
• resulting in a top stream from the second column comprising the recovered aliphatic hydrocarbons and a bottom stream from the second column comprising water and the organic solvent.