Refinery blending operations are the “cash registers” since it “…is the last chance to optimize the final saleable product, as well as the final opportunity to achieve as close to product specifications as possible.”
A recent RBN Energy blog post, The Price You Pay (For Premium Gasoline) – The Widening Price Differential Between Premium And Regular Gasoline, notes the growing cost spread between regular and higher octane grades of gasoline:
…as of July 2017 the premium -vs.-regular differential reached $0.53/gallon — more than double the differential in 2012.
Over the past 12 months, the premium-vs.-regular price spread at the pump has consistently exceeded $0.50/gal (more than $3.50/octane-barrel).
This pricing differential makes it even more important for refineries to optimize their blending operations so as not to giveaway octane levels which could be sold more profitably in higher grades. Also, with increasing shale oil production in the U.S., refineries can purchase these sources of crude oil for less. But these lighter crude oils also have lower octane ratings which must be carefully managed in blend operations.I caught up with Emerson’s Sudhir Jain to discuss the RBN Energy post and how refiners are addressing the challenge to optimize their blending operations. Sudhir explained that optimized and efficient inline blending control starts with accurate and reliable measurements.
These instruments are part of integrated blending skids which accurately dose the component ratios into a blend header equipped with an in-line mixer. Fourier Transform Near Infrared (FTNIR) spectroscopy analyzers provide real-time property analysis to meet product specifications with excessive octane giveaway. An integrated control system with inline blending control assists the operations staff in managing, operating, controlling, optimizing, and reporting on all blend operations.
Sudhir noted that typically, the refinery planner and schedulers develop a 7-10-day plan based on season, orders and market conditions for the various grades of gasoline along with the inventory levels and physical properties of the blend components (Reformate, FCC Naphtha, Alkylate, Ethanol, Isomerate, etc.)
These offline plans are then transferred to the blend operators and engineers to put into the blend control systems to execute the plans. Blend solutions such as SmartProcess Blend Control & Optimization provide both offline and online optimization and provided an automated path to transfer the plans once approved to the online system.
The same optimization algorithm is used in the online version so adjustments can be made to the plan as market and inventory conditions change during the window of production. By having the flexibility to rapidly adjust to changing conditions, the refinery can meet the blending requirements and correct issues before they lead to non-compliance with the specification.