Deep desulfurization of hydrocarbon feeds containing undesired organosulfur compounds to produce a hydrocarbon product having low levels of sulfur, i.e., 15 ppmw or less of sulfur, is achieved by hydrotreating the feed under mild conditions, and separating the hydrotreated effluent into an aromatic-rich fraction which contains a substantial amount of the aromatic refractory and sterically hindered sulfur-containing compounds, and an aromatic-lean fraction. The aromatic-rich fraction is contacted with isomerization catalyst, and the isomerized aromatic-rich fraction is recycled to the mild hydrotreating process.

A column for the liquid-liquid extraction of a feedstock by an extraction solvent, containing sieve trays (P.sub.i) for a dispersed phase (B) to pass through, the sieve trays being spaced apart by an inter-tray space (8), and riser/downcomer conduits (6), a riser/downcomer conduit being an opening that allows a continuous phase (A) to pass through a sieve tray, the extraction column (1) containing, in alternation, type-I sieve trays containing two peripheral riser/downcomer conduits, and type-II sieve trays containing a single central riser/downcomer conduit, wherein: the height H1 of the inter-tray spaces situated directly downstream of the type-I trays, in the direction of flow of the continuous phase, is greater than the height H2 of the inter-tray spaces positioned directly downstream of the type-II trays. Also, a liquid-liquid extraction method that makes use of the liquid-liquid extraction column.

A liquid-liquid-solid extraction process is disclosed for isolating natural products from a feedstock stream containing a biomass in an aqueous salt solution. The process includes forming a dispersion by contacting the feedstock stream with an extraction solvent in an extraction zone; passing the dispersion to a separation zone; separating the dispersion into multiple layers at a temperature of about 90 C. or less, the layers including: a solvent extract layer, a raffinate layer and a rag layer, and isolating at least part of the solvent extract layer, at least part of the raffinate layer and/or at least part of the rag layer.

The present invention relates to a process for the selective extraction of a salt to be extracted from a brine to be treated containing the said salt to be extracted, characterized in that: the brine to be treated (S1) is sent to an initial extraction stirrer-mixer (1a) into which a liquid hydrophobic organic phase is also introduced, the said brine and the said liquid hydrophobic organic phase are mixed in the said initial extraction stirrer-mixer (1a), and the mixture is sent to an initial decanter-separator (1d, 1dc), in order to obtain: a brine from which salt to be extracted has been removed; and an organic phase loaded with salt to be extracted; the brine from which the salt to be extracted has been removed is recovered; the organic phase loaded with salt to be extracted is sent to an initial washing stirrer-mixer-decanter-centrifugal separator (5a, 5dc or 7a, 7dc), in order to obtain a purified organic phase loaded with salt to be extracted, which is sent to a so-called organic heat exchanger (1e) in which it is heated before being sent to a so-called initial regeneration column (1c; 2c), in which a countercurrent exchange is carried out with hot water at a higher temperature than that of the initial brine, in order to obtain: a water containing the salt to be extracted; and a regenerated organic phase, having lost the salt to be extracted; the regenerated organic phase is recycled to the initial extraction stirrer-mixer (1a).