Ultra-Deep Gasoline Desulfurization Process by ExxonMobil

Application: ExxonMobil’s Research & Engineering’s (EMRE’s) SCANfining technology reduces sulfur in FCC gasoline to levels as low as <10 wppm by selective hydrotreating to maximize octane retention with the SCANfining technology.

Description: The feed is mixed with hydrogen, heated with reactor effluent exchange and passed through a pretreat reactor for diolefin saturation. After further heat exchange with reactor effluent and preheat using a utility, the hydrocarbon/hydrogen mixture enters the main reaction section which features ExxonMobil Research and Engineering Co. (EMRE) proprietary selective catalyst systems. In this section of the plant, sulfur is removed in the form of H2S under tailored process conditions, which strongly favor hydrodesulfurization while minimizing olefin saturation.

The feed may be full-range, intermediate or heavy FCC-naphtha fraction. Other sulfur-containing streams such as light-coker naphtha, steam cracker or light straight-run naphthas can also be processed with FCC naphthas. SCANfining technology can be retrofitted to existing units such as naphtha or diesel hydrotreaters and reformers. SCANfining technology also features ExxonMobil’s proprietary reactor internals such as Automatic Bed Bypass Technology for onstream mitigation of reactor plugging/pressure drop buildup.

For high-sulfur feeds and/or very low-sulfur product, with low levels of product mercaptans variations in the plant design from SCANfining I Process to the SCANfining II Process for greater HDS selectivity, or addition of a ZEROMER process step for mercaptan conversion, or addition of an EXOMER process unit for mercaptan extraction.

EMRE has an alliance with Kellogg Brown & Root (KBR) to provide SCANfining technology to refiners and an alliance with Merichem Chemicals & Refinery Services LLC to provide EXOMER technology to refiners.

Yields: Yield of C5 + liquid product is typically over 100 LV%.

Licensor: ExxonMobil Research and Engineering Co.