Hydrocracked bottoms fractions are treated to separate HPNA compounds and/or HPNA precursor compounds and produce a reduced-HPNA hydrocracked bottoms fraction effective for recycle, in a configuration of a single-stage hydrocracking reactor, series-flow once through hydrocracking operation, or two-stage hydrocracking operation. A process for separation of HPNA and/or HPNA precursor compounds from a hydrocracked bottoms fraction of a hydroprocessing reaction effluent comprises contacting the hydrocracked bottoms fraction with an effective quantity of a oxidizing agent to produce corresponding oxidized HPNA compounds and/or oxidized HPNA precursor compounds, and to form an oxidized hydrocracked bottoms fraction. The oxidized hydrocracked bottoms fraction is separated into an HPNA-reduced hydrocracked bottoms portion and an oxidized HPNA portion. All or a portion of the HPNA-reduced hydrocracked bottoms portion is recycled within the hydrocracking operation.

The present invention relates to a process for the separation of aromatic hydrocarbons from a hydrocarbon feed stream comprising contacting a hydrocarbon feed stream with a solvent for aromatics (aromatics solvent) to provide an aromatics-laden solvent stream and subjecting the aromatics-laden solvent stream to solvent regeneration to provide regenerated aromatics solvent and an aromatics stream.

The present invention relates to a process for the separation of aromatic hydrocarbons from a hydrocarbon feed stream comprising contacting a hydrocarbon feed stream with a solvent for aromatics (aromatics solvent) to provide an aromatics-laden solvent stream and subjecting the aromatics-laden solvent stream to solvent regeneration to provide regenerated aromatics solvent and an aromatics stream.

Optimizing power generation from waste heat in large industrial facilities such as petroleum refineries by utilizing a subset of all available hot source streams selected based, in part, on considerations for example, capital cost, ease of operation, economics of scale power generation, a number of ORC machines to be operated, operating conditions of each ORC machine, combinations of them, or other considerations are described. Recognizing that several subsets of hot sources can be identified from among the available hot sources in a large petroleum refinery, subsets of hot sources that are optimized to provide waste heat to one or more ORC machines for power generation are also described. Further, recognizing that the utilization of waste heat from all available hot sources in a mega-site such as a petroleum refinery and aromatics complex is not necessarily or not always the best option, hot source units in petroleum refineries from which waste heat can be consolidated to power the one or more ORC machines are identified.

Optimizing power generation from waste heat in large industrial facilities such as petroleum refineries by utilizing a subset of all available hot source streams selected based, in part, on considerations for example, capital cost, ease of operation, economics of scale power generation, a number of ORC machines to be operated, operating conditions of each ORC machine, combinations of them, or other considerations are described. Recognizing that several subsets of hot sources can be identified from among the available hot sources in a large petroleum refinery, subsets of hot sources that are optimized to provide waste heat to one or more ORC machines for power generation are also described. Further, recognizing that the utilization of waste heat from all available hot sources in a mega-site such as a petroleum refinery and aromatics complex is not necessarily or not always the best option, hot source units in petroleum refineries from which waste heat can be consolidated to power the one or more ORC machines are identified.

We disclose a process for purification of hydrocarbons, suitable for a wide range of contexts such as refining bunker fuels to yield low-sulphur fuels, cleaning of waste engine oil (etc) to yield a usable hydrocarbon product, recovery of hydrocarbons from used tyres, recovery of hydrocarbons from thermoplastics etc, as well as the treatment of crude oils, shale oils, and the tailings remaining after fractionation and like processes. The method comprises the steps of heating the hydrocarbon thereby to release a gas phase, contacting the gas with an aqueous persulphate electrolyte within a reaction chamber, and condensing the gas to a liquid or a liquid/gas mixture and removing its aqueous component. It also comprises subjecting the reaction product to an electrical field generated by at least two opposing electrode plates between which the reaction product flows; this electrolytic step regenerates the persulphate electrolyte which can be recirculated within the process. The process is ideally applied in an environment at lower than atmospheric pressure, such as less than 1500 Pa. A wide range of hydrocarbons can be treated in this way. Used hydrocarbons such as engine oils and sulphur-contaminated fuels are prime examples, but there are a wide range of others such as hydrocarbons derived from the pyrolysis of a material having a hydrocarbon content. One such example is a mix of used rubber (such as end-of-life tyres) and used oils (such as engine oils, waste marine oils), which can be pyrolysed together to yield a hydrocarbon liquid which can be treated as above, and a residue that provides a useful solid fuel.

A method for sulfur removal and upgrading comprising the steps of mixing a heated oil feed and a supercritical water feed in a feed mixer, allowing conversion reactions to occur in the supercritical water reactor, reducing the temperature in the cooling device to produce a cooled fluid, reducing the pressure in the depressurizing device to produce a discharged fluid, separating the discharged fluid in the gas-liquid separator to produce a liquid phase product, increasing the pressure to produce pressurized liquid product, the pressure of pressurized liquid product is greater than the critical pressure of water, processing the pressurized liquid product in the hydration reactor to produce a hydrated oil stream, separating the hydrated oil stream to produce an extracted upgraded oil and an oxygenate concentrated stream, the oxygenate concentrated stream comprises the oxygenates, and processing the extracted upgraded oil in the hydrotreater to produce a desulfurized upgraded oil.

A method for sulfur removal and upgrading comprising the steps of mixing a heated oil feed and a supercritical water feed in a feed mixer, allowing conversion reactions to occur in the supercritical water reactor, reducing the temperature in the cooling device to produce a cooled fluid, reducing the pressure in the depressurizing device to produce a discharged fluid, separating the discharged fluid in the gas-liquid separator to produce a liquid phase product, increasing the pressure to produce pressurized liquid product, the pressure of pressurized liquid product is greater than the critical pressure of water, processing the pressurized liquid product in the hydration reactor to produce a hydrated oil stream, separating the hydrated oil stream to produce an extracted upgraded oil and an oxygenate concentrated stream, the oxygenate concentrated stream comprises the oxygenates, and processing the extracted upgraded oil in the hydrotreater to produce a desulfurized upgraded oil.

A process for the treatment of a hydrocracking unit bottoms recycle stream, and preferably the fresh hydrocracker feed to remove heavy poly-nuclear aromatic (HPNA) compounds and HPNA precursors employs, in the alternative, an adsorption step which removes most of the HPNA compounds followed by an ionic liquid extraction step to remove the remaining HPNA compounds, or a first ionic liquid extraction step which removes most of the HPNA compounds followed by an adsorption step to remove the remaining HPNA compounds. Ionic liquids of the general formula Q.sup.+A.sup. are identified for use in the process; organic polar solvents are identified for removal of the HPNA compounds in solution. Suitable adsorbents are identified for use in packed bed or slurry bed columns that operate within specified temperature and pressure ranges.

A process for the treatment of a hydrocracking unit bottoms recycle stream, and preferably the fresh hydrocracker feed to remove heavy poly-nuclear aromatic (HPNA) compounds and HPNA precursors employs, in the alternative, an adsorption step which removes most of the HPNA compounds followed by an ionic liquid extraction step to remove the remaining HPNA compounds, or a first ionic liquid extraction step which removes most of the HPNA compounds followed by an adsorption step to remove the remaining HPNA compounds. Ionic liquids of the general formula Q.sup.+A.sup. are identified for use in the process; organic polar solvents are identified for removal of the HPNA compounds in solution. Suitable adsorbents are identified for use in packed bed or slurry bed columns that operate within specified temperature and pressure ranges.