The facility is being designed to process and refine light sweet crude into No. 1 and No. 2 Ultra-Low Sulfur Diesel (ULSD) and secondary products for the local and regional markets. The secondary products produced will be naphtha and residual fuel oil. The refinery will have the capability to produce blended drilling distillates as well, which will be used in oil field applications.
Feedstock Characteristics (Refinery Input)
Not only is the oil contained within the Bakken plentiful, but it is a very high-quality crude oil, very similar to West Texas intermediate (WTI) crude. Oil from the Bakken has an API gravity of 39-40.9 degrees, compared to an API of 39.6 degrees for WTI. Bakken oil also contains significantly less sulfur as a percentage of weight than WTI as well as less asphalt and more mid-range distillates (kerosene and diesel).
Light Gas Oil (LGO), is primarily diesel and kerosene. This diesel fuel is the primary target product of the Trenton Refinery. The Trenton Refinery will produce on average approximately 6,000 barrels of diesel fuel per day before blending with other distillates which will significantly increase the diesel fuel yield. Kerosene is the lighter of the two fuels and is essentially premium #1 Diesel and is in short supply in the Williston Basin where its properties make it ideal for cold-weather use.
The Environmental Protection Agency (EPA) has established Ultra-Low Sulfur Diesel (ULSD) standards requiring ULSD be used in all mobile diesel engines newer than 2007 and requiring all diesel fuel produced and imported into the United States to meet the 15 parts per million (ppm) sulfur requirements by 2014. All on-highway, off-road, locomotive, and marine-use diesels must meet the 15 ppm sulfur requirement by 2015. This rule does not apply to heating oil or stationary applications (Non-Road). The Non-Road fuel applications in the area would include use in generators, power plants, and crude-oil drilling. Currently, none of the local distributors have storage to segregate Ultra-Low Sulfur Diesel from low sulfur diesel. Consequently, almost all diesel fuel distributed locally already meets the ULSD standard of 15 ppm sulfur. Trucks would also have to be assigned specifically for hauling lowsulfur diesel or cleaned prior to hauling Ultra-Low Sulfur Diesel, making its use impractical.
Ultra-Low Sulfur Diesel will be required for on and off-road uses in North Dakota (and all other U.S. states except Alaska) after December 2013. For these reasons there will be literally no market for high or low sulfur diesel (5,000 ppm and 500 ppm respectively) except for drilling distillate. The Trenton Refinery is designed to produce ULSD exclusively except for the AGO industrial diesel which may be marketed for use as drilling distillate.
Naphtha is a volatile, colorless byproduct of petroleum distillation. Naphtha is also known as white gas, and when processed in catalytic reforming, it becomes high-octane motor gasoline. Since the process of making gasoline (catalytic reforming) is capital intensive and not justified given the current demand in the region, the naphtha produced will be sold in the Canadian market as diluent for tar sands oil transportation or to other refineries as reformer feedstock.
Kerosene is thin, light-colored oil typically used as fuel for heating and cooking, in lamps, and in jet engines. Given current commodity prices and cost of post-processing for jet fuel, the kerosene product stream will be refined to #1 diesel fuel or blended with the diesel fuels to maximize the refinery’s diesel output.
Atmospheric gas oil (AGO) is the equivalent of industrial fuel oil grade #4 Diesel. Until the market can be proven for this material’s suitability as a drilling distillate, it is expected to be sold as catalytic cracking feedstock to Midwest or Gulf Coast refineries. There is very limited market potential for this product directly, however its qualities have been evaluated as highly suitable as a premium feedstock for catalytic cracking or coking, or, when blended with other petroleum components, for use as drilling distillate in the well fields.
Heavy Fuel Oil
The residual distillation product, or atmospheric tower bottoms (ATB’s), is also known as Heavy Fuel Oil (HFO) or Residual Fuel Oil (RFO), and is classified as #6 Diesel. In the marine industry it is also known as Bunker C Fuel Oil, after the US Navy designation. Heavy Fuel Oil is used as fuel for very large diesel engines. Bakken crude’s distilled ATB’s are relatively light compared to many other crude feedstocks, in the range of API 20 gravity. They are also relatively free of asphaltenes and heavy metals and relatively low in sulfur (3,960 ppm), making them a premium ATB product. The atmospheric tower bottoms could be sold into the bunker fuel market, or most likely as feedstock for coker units or fluid catalytic converter (FCC) units, which take this heavy product and produce diesel, coke (in the case of the coker unit) and other distillation products.
Due to the desulfurization technology selected for the Trenton Refinery, namely the use of a LO-CAT desulfurization unit and distillate hydrotreater, elemental sulfur will be an inherent by-product. Sulfur can be used for the production of sulfuric acid or as an element of fertilizer.