Process and vessel for removing one or more sulfur compounds (UOP)

Process and vessel for removing one or more sulfur compounds (UOP)

Type	Patent
Inventor	Aziz Sattar
Inventor	Daniel K. Aiken
URL	Free Full Text Source:  http://www.google.com/patents/US20140163294
Assignee	Boreskov Institute of Catalysis, Siberian Branch of Russian Academy of Sciences, UOP
Patent Number	US20140163294 A1
Issue Date	Jun 12, 2014
Abstract	One exemplary embodiment can be a process for removing one or more sulfur compounds from a first liquid. The process can include passing the first liquid through a first inlet and a second liquid through a second inlet, and passing the first liquid through a first outlet and the second liquid through a second outlet of a vessel. The vessel may further have a plurality of vortex contactors. Often, the plurality of vortex contactors has a first vortex contactor, in turn including at least one wall and a frustum. The at least one wall can form a perimeter about an interior space and include a first side and a second side forming a passageway communicating the first liquid from an exterior to the interior space, and a frustum positioned proximate to the passageway and abutting the at least one wall for facilitating contacting of the first and second liquids to extract the one or more sulfur compounds from the first liquid to the second liquid. DESCRIPTION OF THE RELATED ART Current industry practice to extract one or more mercaptan compounds from a hydrocarbon stream can use a water-based caustic solvent. Often, the hydrocarbon stream and the caustic solvent are mixed and then the hydrocarbon and aqueous phases are separated by settling or decanting. The mixing and phase separation operations may be done in a stage wise manner typically involving mechanically or hydraulically-driven intimate mixing of the two phases followed by a settling stage. Generally, the settling stage requires a large vessel volume, such as a large diameter and a tangent length, to allow the dispersed phase to coalesce and separate from the continuous phase under near stagnant conditions. Usually, this large volume minimizes the entrainment or carryover of the dispersed phase in the continuous phase as it exits the settling volume. Alternatively, a vertically oriented column with multiple stages of contacting trays for liquid-liquid extraction of primarily mercaptan sulfur contaminants from one or more hydrocarbons may use caustic as a solvent in a counter-current flow configuration. Typically, the last tray before the treated hydrocarbon exits the column is followed by a disengaging distance for gravity-aided coalescing/settling of caustic, often followed by wire mesh packing or other coalescing media that can provide the fine coalescing/separation of two immiscible liquids. The packing, in turn, is usually followed by an additional disengaging volume to allow for further separation of caustic from hydrocarbons. Another approach for separating caustic from hydrocarbon may utilize a non-dispersive contacting device, such as a fiber film contactor, for extraction followed by a horizontal settler that allows for further separation of caustic from hydrocarbon primarily from droplet coalescence and gravity settling. The use of a mixer-settler device may be amenable to modular supply because the contacting device usually does not require extra ordinary field erection equipment. However, such mixer-settler devices may fail to achieve the required phase mixing and phase separation. Thus, it is desirable to obtain a device that obtains the required phase mixing and separation while minimizing the number and size of vessels to facilitate transportation and installation.