Process and apparatus for the extraction of aromatic compounds from a hydrocarbon charge

摘要

Extraction process for aromatic components in a hydrocarbon batch comprises intimately contacting the batch in counter-flow with a liquid solvent which is immiscible with the batch and which extracts the aromatic components. Phase separation produces a product with low aromatic components and an extraction fluid enriched with aromatics. The process has the following stages: (a) putting in intimate contact in counter-flow the batch and a liquid solvent at least partially by means of at least one structured packing element (31) such as in static mixers, and (b) at least part of the extract which is rich in solvent and in aromatic components is separated by liquid- liquid separation (26) into a phase rich in solvent and without product, which is evacuated, and a phase rich in product and impoverished in solvent which is recycled at its outlet. Apparatus to carry out the above process comprises an extraction column, at the top of which the solvent is introduced as the batch is introduced at the bottom. The apparatus also includes an extraction line for the product at the top of the column and an extraction line for the extract at the bottom of the column. At least one structured packing element is placed inside the column, and the outlet line for the extract includes means of recycling the product- rich phase to the bottom of the column.