Maintaining safety and reliability in process control applications isn't easy to begin with, but evaluating dozens of feedstocks at the same time and managing them for maximum profitability is even more difficult.
This is the challenge that Valero Energy Corp. faces every day in its many refineries in North America, the U.K. and elsewhere. Fortunately, it's been a longtime user and partner with AspenTech and has employed its AspenPlus, PIMS, DMC and other solutions at every stage of its manufacturing processes for many years.
"We're relentless in improving the reliability and safety of our operations, and this is especially important because research shows that more reliable operations are typically safer operations and more profitable operations," says Greg Bram, senior vice president for supply chain optimization at Valero.
Bram presented "Valero's Optimization Journey" at AspenTech Optimize 2015 on May 4 at the Westin Boston Waterfront Hotel in Boston.
Bram reports that Valero initiated new reliability programs in beginning in the mid-2000s and made further gains with operations benchmarks since 2008 and especially last year. In fact, its refinery utilization rate increased from 87% in 2011 to 96% in 2014.
"Seven of our refineries are in the first quartile in mechanical availability," explained Bram. "We also try to link our top performing plants to our worst performing plants and blend their procedures to fix chronic reliability problems. Every bit of improvement we can get out of our processes goes directly to profit. We analyze approximately 100 feedstocks daily, so it's essential for us to know that they're modeling properly. AspenTech's products are mission-critical to how we plan out operations."
Bram adds that Valero has used AspenTech's software to help it decide when to shift about 10% of its crude oil between different end products. In general, this enables Valero to pick the best times and conditions for producing more profitable products from less costly raw materials and save about 10 cents per barrel in operating margin, which adds up to about $80-$100 million per year.
"Feedstock and product optimization opportunities are determined by results generated by PIMS and AspenPlus when they evaluate, for example, changing domestic crude availability versus medium-sour or domestic sweet crude alternatives, or when we seek the lowest-cost location for producing export-grade gasoline," explains Bram. "Accurate, mass-balanced yield data provided by AORA is key to developing models that accurately reflect individual unit and overall refinery performance. Execution of profit maximization strategies requires continuous, real-time control of key process variables using advanced process control (APC) algorithms.
"We also recently handled our distillation production differently and blended our crude in more managed way, so formerly significant dips in our process would only make much littler ripples," says Bram. "This can add about $10 per barrel, so we're also working with AspenTech on developing adaptive modeling efforts. We sit on AspenTech's advisory board, and we even hold annual roundtable meetings where we look for other opportunities to collaborate."
To handle operational fluctuations brought on by the emergence of North American shale oil and gas production and hydraulic fracturing operations, Bram adds that Valero relies on AspenTech's modeling, simulation and optimization software to successfully handle wider ranges and new types of feedstocks. "We need to be confident of our tools, so we can know that we've captured our best opportunities and not missed them," adds Bram. "U.S. oil and gas production has been way up and then slowed a bit recently, and we've been able to respond by running more Gulf crude and making more products at our Quebec refinery, but its our PIMS and AspenPlus tools that let our people come with new production and product ideas and then make them into realities that add value—with as much as a 50% return in some areas."