Motiva Norco Refining Main Process Units
At Motiva Norco Refining, there are seven main areas that we focus on to produce gasoline, jet fuel, diesel and other byproducts from crude oil. These areas are:
- Distilling Unit (DU-5)
- Residual Catalytic Cracking Unit (RCCU)
- Hydrocracking Unit (HCU)
- Coking Unit (COKER)
- Alkylation/MTBE/Kerosene Treaters (Alky)
HOW THEY OPERATE:
The DU – 5 takes in crude oil and distilling it into various components for further Processing in other units. Distillation is the process of boiling raw materials that are composed of complex molecules in order to separate them into useful or saleable products. The distillation unit uses atmospheric and vacuum distillation and steam stripping to physically separate crude oil into fractions of specific boiling ranges. The lighter fractions or products can undergo further processing or, in some cases, be used as blending stocks. The heavier products, such as gas oils, are sent to the RCCU or HCU as feedstocks.
The RCCU cracks molecules in the product streams coming from the distillation unit. Cracking is the process in which you separate or break up molecules into their various component parts. Catalytic cracking uses heat and catalyst to convert heavy oils into more valuable lower molecular weight products such as propylene, butylene, gasoline and distillates. The feedstock is primarily vacuum gas oils with a boiling range of about 600-1000 degrees Fahrenheit.
The HCU receives raw materials such as diesel range (and slightly heavier materials) from DU-5 and converts it into gasoline and lighter by-products in a hydrogen-rich atmosphere. The unit contains two stages. The main function of the 1st stage is to remove nitrogen and sulfur (catalyst poisons) before routing the oil to the 2nd stage. The main function of the 2nd stage is to convert (crack) 1st stage product into gasoline and lighter products. In the 2nd stage, oil and hydrogen are fed to a charge heater, a set of three parallel hydrocracking reactors followed by a series of separators, a main fractionator and a saturates gas plant. The unit typically operates to 95% conversion and achieves a high yield of heavy Naphtha and gasoline blending components. Other components produced by this unit include jet fuel, furnace oil and heating oil.
The COKER heats heavy oils and thermally cracks them in a large drum. Lighter hydrocarbons and coke are produced. The vapors from the drum are then charged to the fractionator while the coke remains in the drum. The fractionator separates these vapors into fractions of specific boiling ranges. The lighter fractions are sent to other units in the plant for processing. The coke remaining in the drums is removed and sold as high-quality anode grade coke. This coke is ultimately used in the manufacturing of aluminum.
The ALKY is primarily responsible for producing the necessary additives that are blended into gasoline to boost the octane. The alkylation reaction involves a sulfuric acid catalyst and reacts olefins with isobutane to form the high-octane gasoline blending component called alkylate. The major source of the olefin feed to the ALKY plant is from the RCCU. The ALKY department consists of an Alkylation plant and MTBE unit (Methyl Tertiary Butyl Ether). The units produce the gasoline additives for boosting octane. In addition, the kerosene treaters in this department are responsible for upgrading the kerosene for jet fuel usage.
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