PTQ Q4 2024 Issue

APC advances FCC unit performance at Pemex Deer Park refinery

In addition to exploring the complex design and processes behind an advanced process control solution, the benefits gained are discussed in this case study

Mohamed Abokor Pemex Deer Park refinery Michelle Wicmandy KBC (A Yokogawa Company)

T he global demand for light oils is on the rise, driven by factors such as increased energy consumption and geopolitical shifts. According to J. P. Morgan Research,1 world oil demand is projected to reach 106.9 million barrels per day (mbd) by 2030, surpassing the levels of 2023 by 5.5 mbd. This upward trend is primarily fuelled by population growth and escalating energy consumption in developing nations, which outweigh energy efficiency initiatives in these economies. Refiners are facing the challenge of meeting this grow - ing demand for refinery products while dealing with the decreasing quality of crude oils and lighter product specifi - cations due to environmental constraints. To navigate these complexities and achieve optimal performance, refineries are turning to technologies like advanced process control (APC). Built in 1929, the Pemex Deer Park refinery in Houston, Texas, serves as a prime example of a traditional refin - ery that has successfully integrated technology with leg - acy systems to achieve stellar results. With a production capacity of 340,000 barrels per day (bpd) for motor fuels, such as gasoline, diesel, and jet fuel, this refinery operates 24/7 year-round. To enhance its operations, the refinery implemented an APC system known as the Platform for Advanced Control and Estimation (PACE), which improves the efficiency of its fluid catalytic cracking (FCC) unit by reducing the fluctuation on key variables. In addition to exploring the complex design and processes behind this solution, this case study discusses the benefits gained, including improved operator efficiency, tighter con - trol over critical parameters, and optimised product yields. FCC unit role For more than 60 years, the FCC unit has been responsible for transforming heavy hydrocarbon petroleum compounds into valuable products like intermediate distillates, light ole- fins, and petrol. In fact, researchers claim the FCC unit is responsible for producing nearly 45% of the world’s gas - oline supply.2 However, FCC units can be challenging to manage, as they require precise control over numerous intercon- nected processes and variables. To meet modern demands for fuel, the FCC unit is evolving with new technological

advancements. APC technology has improved how refiners approach FCC unit optimisation to achieve new levels of efficiency and performance. Traditional vs modern systems Historically, the Deer Park refinery’s FCC unit relied on a traditional, siloed approach to process control. This setup involved the use of the Shell Multivariable Optimisation Controller (SMOC) and a separate real-time optimisation (RTO) system, each with its own dedicated interface. This fragmented approach created challenges for the operators, who had to navigate between three separate interfaces – APC, RTO, and a Robust Quality Estimator (RQE) – when trying to optimise and efficiently manage the FCC unit. To address these challenges, the refinery embarked on an APC migration project, adopting PACE technology to maximise its capacity to process residual feeds and enhance FCC unit profitability. APC technology has improved how refiners approach FCC unit optimisation to achieve new levels of efficiency and performance Unifying FCC unit operations Due to changing market conditions and profitability targets, the Deer Park refinery needed to capture value by converting low-value feedstock into high-value products like gasoline through a high-temperature cracking reaction facilitated by catalyst. To reduce variation over key processes, designing the right application was crucial. Integrating a sophisticated control architecture within the FCC unit and its gas frac - tionator unit was essential. With a single RTO loop, the refinery can enhance opera - tional efficiency by seamlessly merging three applications: • The first application focused on optimising operations of the reactor regenerator (R&R) and main fractionator (MFRAC). • The second loop focuses on the rectified absorber (RA).

PTQ Q4 2024