ExxonMobil MIDW Process: Innovative Solutions for Production of Low Sulfur Distillates Using Selective Dewaxing and Advanced Hydrotreating Catalysts
Publication Date: 2012-May-08
The IP.com Prior Art Database
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ExxonMobiI MIDW Process:
Innovative Solutions for Production of Low Sulfur Distillates Using Selective Dewaxing and Advanced Hydrotreating Catalysts
William J. Tracy, Girish K. Chitnis, William J. Novak, Terry E. Helton ExxonMobil Research and Engineering
Akzo Nobel Catalysts
3rd European Catalyst Technology Conference
Amsterdam, The Netherlands February 26-27,2002
ExxonMobil has continued to refine the MlDW dewaxing process, which is finding increased use, especially for productionof low sulfur diesel fuel when cold flow improvement is also required. Inthis case an HDTIMIDW "stacked bed" catalyst arrangement provides the necessary catalytic functionality. For the future, more complex catalyst stacking schemes can be envisioned when other diesel quality improvements (e.g., T95 reduction, higher cetane) are also desired. In commercial practice, stacking beds of different types of catalysts presents a number of issues, including modified start-up procedures to providethe highest possible initial catalyst activities. To this end, ExxonMobil has developed a pre-activated, distillate selective MlDW catalyst version, which simplifies co-loading with other catalyst types. Recent commercial start-up of OMV's MAKFining MlDW unit in Germany usinq Akzo Nobel supplied catatlyst and enGineered by Halliburton KBR demonstrates the stacking concept for a unit producing <I0-ppmw sulfur diesel. For future applications, improved HDT catalyst technology has extended the refractory feedstock operating range of MIDW.
introduction (Slide I)
ExxonMobil announced a new fuels dewaxing process in 1996'. Mobil jsomerization -
Deyaxing, or more simply MIDW, lowers the pour point of waxy gas oils by hydroisomerizationand selective hydrocracking of paraffins. Premiumquality, low pour distillates are obtained by retaining paraffins in the distillate boiling range. Afamily of proprietary, dual-functional noble metal-molecular sieve catalysts is used to isomerize
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paraffins in the presenceof aromatics. MlDW employs a fixed-bed reactor and operating conditions are flexible. Low hydrogen pressures similar to those used for HDT of light gas oils are generally sufficient. A wide range of feeds can be processed, from kerosene and diesel fuels to highly paraffinic hydrocracker bottoms. Products include jet fuels of exceptional quality, high cetane low sulfur diesel fuels, and low pour bottoms for specialty applications.
MlDW Commercial Status (Slide 2)
The MIDW process is commercially proven. The first MIDW unit was started-up in 1990 at ExxonMobil's Jurong refinery in Singapore. The successful Jurong MlDW application takes a waxy MPHC (moderate pressure hydrocracker) bottoms feed and converts it into premium quality kerosene, diesel, and low pour, low sulfur fuel oil.
Since its introduction to the general market in 1996, industry interest in MIDW has focussed primarily on prod...