Methods for preventing elemental sulfur deposition from a hydrocarbon fluid is disclosed. A mercaptan is added to a hydrocarbon fluid that has elemental sulfur and reacted with the elemental sulfur to produce a disulfide and hydrogen sulfide. Amines and/or surfactants can assist with the process. Secondary reactions between the disulfide and the elemental sulfur result in a polysulfide and a solvated sulfur-disulfide complex. The disulfide, hydrogen sulfide, polysulfide and solvated sulfur-disulfide complex do not deposit, and can optionally be removed.

It has been discovered that solid contaminants in a mixture of a hydrocarbon phase and an aqueous phase may be retained in the hydrocarbon phase by introducing to the mixture an effective amount of an oil-wetting additive to retain at least a portion of the solid contaminants in the hydrocarbon phase as contrasted with an aqueous phase. The oil-wetting additive can be a surface-active additive including, but is not necessarily limited to, drilling fluid additives, surfactants, antifoulants, nanoparticles and combinations thereof.

It has been discovered that solid contaminants in a mixture of a hydrocarbon phase and an aqueous phase may be retained in the hydrocarbon phase by introducing to the mixture an effective amount of an oil-wetting additive to retain at least a portion of the solid contaminants in the hydrocarbon phase as contrasted with an aqueous phase. The oil-wetting additive can be a surface-active additive including, but is not necessarily limited to, drilling fluid additives, surfactants, antifoulants, nanoparticles and combinations thereof.

Metals, such as mercury, may be removed from aqueous, hydrocarbon, or mixed oilfield or refinery fluids by: applying a sulfur compound having the general formula HS—X, where X is a heteroatom substituted alkyl, cycloalkyl, aryl, and/or alkylaryl group either alone or in combination with or as a blend with at least one demulsifier, a buffering agent, a pour point depressant, and/or a water clarifier to chelate the at least one metal and form a chelate complex of the sulfur compound with the at least one metal and then separating the chelate complex from the fluid.

Metals, such as mercury, may be removed from aqueous, hydrocarbon, or mixed oilfield or refinery fluids by: applying a sulfur compound having the general formula HS—X, where X is a heteroatom substituted alkyl, cycloalkyl, aryl, and/or alkylaryl group either alone or in combination with or as a blend with at least one demulsifier, a buffering agent, a pour point depressant, and/or a water clarifier to chelate the at least one metal and form a chelate complex of the sulfur compound with the at least one metal and then separating the chelate complex from the fluid.

Ionic liquid containing compositions may be used in the production, recovery and refining of oil and gas. In addition, they may be used to treat cooling water and/or to inhibit and/or prevent corrosion of metals.

The present disclosure relates to a method and an apparatus for self-heat-extracting flash evaporation of a sulfuric acid alkylation reaction product. There is provided a method for self-heat-extracting flash evaporation of a sulfuric acid alkylation reaction product. One step is to coalesce and vaporize a preliminarily distributed sulfuric acid alkylation reaction product to cause preliminary vaporization of a hydrocarbon therein, thereby taking heat away and preliminarily separating the hydrocarbon from sulfuric acid. Another step is to subject the preliminarily separated alkylation reaction to reinforced separation, where the hydrocarbon is further vaporized to take heat away and further separate the hydrocarbon from the sulfuric acid. There is also provided an apparatus for self-heat-extracting flash evaporation of a sulfuric acid alkylation reaction product.

The present disclosure relates to a method and an apparatus for self-heat-extracting flash evaporation of a sulfuric acid alkylation reaction product. There is provided a method for self-heat-extracting flash evaporation of a sulfuric acid alkylation reaction product. One step is to coalesce and vaporize a preliminarily distributed sulfuric acid alkylation reaction product to cause preliminary vaporization of a hydrocarbon therein, thereby taking heat away and preliminarily separating the hydrocarbon from sulfuric acid. Another step is to subject the preliminarily separated alkylation reaction to reinforced separation, where the hydrocarbon is further vaporized to take heat away and further separate the hydrocarbon from the sulfuric acid. There is also provided an apparatus for self-heat-extracting flash evaporation of a sulfuric acid alkylation reaction product.

The invention relates to the dissolution of amorphous dithiazine (a-DTZ) or polythioformaldehyde or other polymeric by-products of the treatment of hydrocarbon products (a-DZT) to remove them from surfaces. These are solids that build up on surfaces of processing plant and are resistant to most chemical treatment. The treatment requires treating the surface with an effective amount of a mercaptan or an amine. Surfactants to keep the dissolved a-DTZ or other components from redepositing elsewhere are also described, as is the use of hydrogen sulfide to add in removal by mercaptans.

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 sulfonation agent to produce corresponding sulfonated HPNA compounds and/or sulfonated HPNA precursor compounds, and to form a sulfonated hydrocracked bottoms fraction. The sulfonated hydrocracked bottoms fraction is separated into an HPNA-reduced hydrocracked bottoms portion and a sulfonated HPNA portion. All or a portion of the HPNA-reduced hydrocracked bottoms portion is recycled within the hydrocracking operation.