Abstract: Disclosed is a process for the selective hydrogenation of diolefins and sulfur compounds that are contained in a pyrolysis gasoline feedstream. The process includes utilizing a single hydrotreating reaction stage by introducing the pyrolysis gasoline feedstock that includes a diolefin concentration and an organic sulfur concentration into a reactor that is loaded with a high activity hydrotreating catalyst and which is operated under selective hydrogenation conditions. A reactor effluent having a reduced diolefin concentration and a reduced organic sulfur concentration is yielded from the reactor and is separated into a portion that is recycled as a reactor feed. The remaining portion of the reactor effluent is passed downstream for further processing or handling.

Abstract: Disclosed is a process for the removal of sulfur from a fuel gas stream that additionally contains diolefins and oxygen as well as organic sulfur compounds by pretreating the fuel gas stream in a pretreatment reactor in order to significantly reduce the amounts of any diolefins and oxygen contained therein prior to the hydrodesulfurization in a hydrotreater reactor wherein organic sulfur compounds are converted to hydrogen sulfide. The hydrogen sulfide formed is removed from the hydrotreated gas stream by use of an absorption treatment method, such as amine treatment, to yield a treated fuel gas stream having a reduced concentration of hydrogen sulfide and an overall sulfur content that is low enough to meet stringent sulfur regulation requirements.

Abstract: Disclosed is a process for the selective hydrogenation of diolefins and sulfur compounds that are contained in a pyrolysis gasoline feedstream. The process includes utilizing a single hydrotreating reaction stage by introducing the pyrolysis gasoline feedstock that includes a diolefin concentration and an organic sulfur concentration into a reactor that is loaded with a high activity hydrotreating catalyst and which is operated under selective hydrogenation conditions. A reactor effluent having a reduced diolefin concentration and a reduced organic sulfur concentration is yielded from the reactor and is separated into a portion that is recycled as a reactor feed. The remaining portion of the reactor effluent is passed downstream for further processing or handling.

Abstract: Disclosed is a process for the removal of sulfur from a fuel gas stream that additionally contains diolefins and oxygen as well as organic sulfur compounds by pretreating the fuel gas stream in a pretreatment reactor in order to significantly reduce the amounts of any diolefins and oxygen contained therein prior to the hydrodesulfurization in a hydrotreater reactor wherein organic sulfur compounds are converted to hydrogen sulfide. The hydrogen sulfide formed is removed from the hydrotreated gas stream by use of an absorption treatment method, such as amine treatment, to yield a treated fuel gas stream having a reduced concentration of hydrogen sulfide and an overall sulfur content that is low enough to meet stringent sulfur regulation requirements.

Abstract: A selenium-containing aqueous stream may be used as a quenching water stream and optionally a cutting water stream in a delayed coking process to effectuate the removal of selenium from the selenium-containing aqueous stream resulting in the formation of a selenium-coke product. In addition, selenium may be concentrated in selenium-containing stripped sour water streams by recycling the stream in one or more hydroprocessing units and one or more sour water stripper units and subsequently removed by using a portion of the selenium-containing stripped sour water stream as a quenching water stream and optionally a cutting water stream in a delayed coking process.