Demulsification and Extraction of Biochemicals from Crude and its Fractions Using Water and Subcritical/Supercritical Carbon Dioxide as Proton Pump with pH Tuning without Precipitating Oil Components

摘要

A demulsification process for extracting surface active biochemical products from crude oil and its fractions when they are used as feedstock during biochemical productions utilizes subcritical/supercritical CO2 as a proton pump. The process also includes a pH tuning step, thereby inducing demulsification and precipitation of biochemical products into the aqueous phase, but avoiding asphaltene precipitation by apriori addition of resinous solvents derived from crude oil or bioresources. The biochemical products are then extracted from the aqueous phase via temperature change or some other technique.

主权项

1. A method for demulsification and extraction of biochemicals from crude oil and its fractions without precipitating other surface active molecules that are part of the crude oil comprising the steps of:
mixing a crude oil emulsion with subcritical to supercritical carbon dioxide, the emulsion containing surface active molecules including aromatic resins, asphaltenes and the biochemicals; maintaining the mixture at conditions that cause the pH of an aqueous phase of the emulsion to decrease to a first pH value which causes weakening of an interfacial tension of the emulsion; and maintaining an aromatic resin to asphaltene ratio to be greater than a predefined value such that the asphaltenes are suspended/solvated by the aromatic resins and asphaltene precipitation is prevented, while the biochemicals precipitate or transfer to the aqueous phase and are extracted therefrom.