Saturation of a pyrolysis stream is achieved while managing exotherms. The pyrolysis stream is split into at least two feed streams for at least two saturation reactors. The process may split the hydrogen stream into at least two streams for the at least two saturation reactors. A recycle stream may also be provided to manage the exotherm. The feed may comprise at least 5 wt % aromatics.

Disclosed herein are methods, systems, and compositions for providing catalysts for tail gas clean up in sulfur recovery operations. Aspects of the disclosure involve obtaining catalyst that was used in a first process, which is not a tailgas treating process and then using the so-obtained catalyst in a tailgas treating process. For example, the catalyst may originally be a hydroprocessing catalyst. A beneficial aspect of the disclosed methods and systems is that the re-use of spent hydroprocessing catalyst reduces hazardous waste generation by operators from spent catalyst disposal. Ultimately, this helps reduce the environmental impact of the catalyst life cycle. The disclosed methods and systems also provide an economically attractive source of high-performance catalyst for tailgas treatment, which benefits the spent catalyst generator, the catalyst provider, and the catalyst consumer.

A method of removing oxygenates from a hydrocarbon stream comprises passing a hydrocarbon stream to a caustic tower having a plurality of loops, contacting the hydrocarbon stream with a sulfided catalyst between a first loop of the plurality of loops and a second loop of the plurality of loops to produce a reaction product, passing the reaction product to the second loop, removing at least a portion of the hydrogen sulfide in the second loop of the caustic tower to produce a product stream, and separating the product stream into a plurality of hydrocarbon streams in a separation zone located downstream of the caustic tower. The hydrocarbon stream comprises hydrocarbons, oxygen containing components, and sulfur containing compounds. At least a portion of the sulfur compounds react in the presence of the sulfided catalyst to produce hydrogen sulfide in the reaction product.

Disclosed herein are methods, systems, and compositions for providing catalysts for tail gas clean up in sulfur recovery operations. Aspects of the disclosure involve obtaining catalyst that was used in a first process, which is not a tailgas treating process and then using the so-obtained catalyst in a tailgas treating process. For example, the catalyst may originally be a hydroprocessing catalyst. A beneficial aspect of the disclosed methods and systems is that the re-use of spent hydroprocessing catalyst reduces hazardous waste generation by operators from spent catalyst disposal. Ultimately, this helps reduce the environmental impact of the catalyst life cycle. The disclosed methods and systems also provide an economically attractive source of high-performance catalyst for tailgas treatment, which benefits the spent catalyst generator, the catalyst provider, and the catalyst consumer.

The present subject matter relates generally to methods for selectively saturating the unsaturated C.sub.2-C.sub.4. More specifically, the present subject matter relates to methods for saturating butadiene and butenes from a hydrocarbon stream before it is combined with a fresh feed and enters a reaction zone. Removing the unsaturates from the hydrocarbon stream before the hydrocarbon stream enters the reaction zone prevents the reactor internals from coking.

The present subject matter relates generally to methods for selectively saturating the unsaturated C.sub.2-C.sub.4. More specifically, the present subject matter relates to methods for saturating butadiene and butenes from a hydrocarbon stream before it is combined with a fresh feed and enters a reaction zone. Removing the unsaturates from the hydrocarbon stream before the hydrocarbon stream enters the reaction zone prevents the reactor internals from coking.

The invention relates to hydrocarbon conversion processes, e.g., to processes for producing acetylene from hydrocarbon and then hydrogenating at least a portion of the acetylene. The invention also relates to polymerizing one or more products derived from the acetylene saturation, and to equipment useful for these processes.

The invention relates to hydrocarbon conversion processes, e.g., to processes for producing acetylene from hydrocarbon and then hydrogenating at least a portion of the acetylene. The invention also relates to polymerizing one or more products derived from the acetylene saturation, and to equipment useful for these processes.

The invention relates to mixtures comprising molecular hydrogen, hydrocarbons, and nitrogen oxides; to processes for removing at least a portion of the nitrogen oxides therefrom; to equipment useful in such processes; and to the use of such hydrocarbons for, e.g., chemical manufacturing.

The invention relates to mixtures comprising molecular hydrogen, hydrocarbons, and nitrogen oxides; to processes for removing at least a portion of the nitrogen oxides therefrom; to equipment useful in such processes; and to the use of such hydrocarbons for, e.g., chemical manufacturing.