Split-shell raffinate columns and methods for use in continuous adsorptive separation processes

A method for separating hydrocarbon mixtures, the method comprising the steps of:

• directing a raffinate stream into a split-shell column, the raffinate stream comprising a raffinate material and a desorbent material, the split-shell column comprising a raffinate column portion and a desorbent rerun column portion;
• separating the raffinate material from the desorbent material in the raffinate column portion of the split-shell column;
• directing a first portion of the desorbent material separated in the raffinate column portion to the desorbent rerun column portion;
• separating the desorbent material into decontaminated desorbent material and heavy contaminants;
• and
• directing the decontaminated desorbent material back into the raffinate column portion.

A split-shell column comprising:

• a raffinate column portion for separating a raffinate material from a desorbent material, wherein the raffinate column portion extends from a bottom of the split-shell column to a top of the split-shell column. a desorbent rerun column portion for separating heavy contaminants from the desorbent material, wherein the desorbent rerun column portion extends from the bottom of the split-shell column but does not extend to the top of the split-shell column,
• wherein a feed to the desorbent rerun column portion is provided from the desorbent material separated in the raffinate column,
• wherein the desorbent rerun column portion occupies a portion of a lower end of the split-shell column and is thermally separated from the raffinate column portion with an insulated dividing wall,
• wherein the desorbent rerun column portion comprises a chimney disposed through a blind tray, and
• wherein the desorbent material separated in the desorbent rerun column portion is directed back into the raffinate column portion through the chimney disposed through the blind tray.