A method for refining fuel oil comprises subjecting fuel oil to an extraction treatment with an extraction agent to extract a light component from the fuel oil, so as to obtain a light oil mixture containing the light component of the fuel oil and the extraction agent. The extraction agent is selected from the group consisting of a matter composed of oil and miscible with the light component of the fuel oil, a non-polar compound in a gaseous state at the room temperature and atmospheric pressure, and a combination thereof. The extraction agent is in a liquid state during the extraction treatment.

Process for the removal of nitrogen-containing compounds from a hydrocarbon feed comprising at least one olefin selected from the C3, C4, C5 and optionally C6 olefins and mixtures thereof comprising solvent extraction comprising monitoring the degradation of the solvent.

A de-asphalting system for solvent de-asphalting including a desasphalter and a controller. The deasphalter defines a contacting zone and a separation zone. The contact zone contacts a feed, including asphaltenes, and a solvent to form a mixture, where the contacting of the feed and the solvent causes at least a portion of the asphaltenes to precipitate out of the mixture. The contacting is disposed at an operating temperature. The separation zone separates the mixture into a de-asphalted oil-comprising material fraction (S+PDAO) and a asphaltene-rich material fraction. The asphaltene-rich material fraction includes the precipitated asphaltenes. The controller controls at least one operating parameter of the deasphalter based on at least on a refractive index of the S+PDAO phase. The operating parameter is selected from: the operating temperature; the composition of the feed; the composition of the solvent; a ratio of the mass of precipitated asphaltenes to the mass of asphaltenes within the feed; and a ratio of the mass of the solvent to the mass of the feed.

A de-asphalting system for solvent de-asphalting including a desasphalter and a controller. The deasphalter defines a contacting zone and a separation zone. The contact zone contacts a feed, including asphaltenes, and a solvent to form a mixture, where the contacting of the feed and the solvent causes at least a portion of the asphaltenes to precipitate out of the mixture. The contacting is disposed at an operating temperature. The separation zone separates the mixture into a de-asphalted oil-comprising material fraction (S+PDAO) and a asphaltene-rich material fraction. The asphaltene-rich material fraction includes the precipitated asphaltenes. The controller controls at least one operating parameter of the deasphalter based on at least on a refractive index of the S+PDAO phase. The operating parameter is selected from: the operating temperature; the composition of the feed; the composition of the solvent; a ratio of the mass of precipitated asphaltenes to the mass of asphaltenes within the feed; and a ratio of the mass of the solvent to the mass of the feed.

A method and a system for purification of contaminated oil. Said method comprises the steps of: providing contaminated oil and a separation aid in a tank (3); waiting for allowing a sludge phase comprising the separation aid together with impurities from the oil to settle in a bottom part (4) of the tank (3); reusing the sludge phase for purification of new contaminated oil.

A method and a system for purification of contaminated oil. Said method comprises the steps of: providing contaminated oil and a separation aid in a tank (3); waiting for allowing a sludge phase comprising the separation aid together with impurities from the oil to settle in a bottom part (4) of the tank (3); reusing the sludge phase for purification of new contaminated oil.

A method for screening a candidate for efficacy as an asphaltene stabilizer comprises: forming a reconstituted oil by dispersing an asphaltene-containing solid in a hydrocarbon fluid; adding an asphaltene stabilizer candidate to the reconstituted oil to give an additized oil; and analyzing the stability of the asphaltenes in the additized oil. The method may be used to select a candidate for use as an asphaltene stabilizer during crude oil production, transportation or processing.

A method for screening a candidate for efficacy as an asphaltene stabilizer comprises: forming a reconstituted oil by dispersing an asphaltene-containing solid in a hydrocarbon fluid; adding an asphaltene stabilizer candidate to the reconstituted oil to give an additized oil; and analyzing the stability of the asphaltenes in the additized oil. The method may be used to select a candidate for use as an asphaltene stabilizer during crude oil production, transportation or processing.

Systems and processes for removing sulfur compounds from a hydrocarbon stream. Sulfur compounds are extracted from a hydrocarbon feed stream with a caustic stream to provide a treated hydrocarbon stream and a rich caustic stream. The sulfur compounds in the rich caustic stream are oxidized in the presence of a catalyst to provide a lean caustic stream. The lean caustic stream is returned to extract sulfur from the hydrocarbon stream. Data such as a concentration of sulfurs species and degree of caustic saturation with the sulfur species in the rich caustic stream may be provided by a sensor, compared against other real-time or historical data and used to provide a recommended adjustment to process conditions associated with an extraction unit, or an oxidation unit, or both.

Systems and processes for removing sulfur compounds from a hydrocarbon stream. Sulfur compounds are extracted from a hydrocarbon feed stream with a caustic stream to provide a treated hydrocarbon stream and a rich caustic stream. The sulfur compounds in the rich caustic stream are oxidized in the presence of a catalyst to provide a lean caustic stream. The lean caustic stream is returned to extract sulfur from the hydrocarbon stream. Data such as a concentration of sulfurs species and degree of caustic saturation with the sulfur species in the rich caustic stream may be provided by a sensor, compared against other real-time or historical data and used to provide a recommended adjustment to process conditions associated with an extraction unit, or an oxidation unit, or both.