[Report] A 'Second Brain' for a 60-Year-Old Refinery... SK Ulsan CLX's AX Experiment

AI Recommends, Humans Decide
AX Integrated into 98 Processes and Aging Facilities
Goal: Annual Productivity Boost of 100 Billion Won by 2030

On September 10, in the control room of the Heavy Oil Upgrading (HOU) process at the SK Innovation Ulsan Complex (CLX) in Nam-gu, Ulsan, dozens of employees in work uniforms were seated in rows, all focused on their monitors in the spacious room. Each operator had five or six screens in front of them, densely filled with numbers and graphs showing factory conditions such as temperature, pressure, and flow rates. The operators continuously monitored the ever-changing figures and adjusted the plant's operating conditions accordingly.

Aerial view of SK Ulsan Complex. SK

The scene was in stark contrast to the view outside. While riding a bus through the facility, people were rarely seen; instead, pipes of varying sizes, huge tanks, and distillation towers filled the windows. The country’s first refinery, operational since 1964, and the latest equipment commissioned in 2020, coexist within a single enclosure. Spanning approximately 8.25 million square meters—three times the size of Yeouido—Ulsan CLX processes 840,000 barrels of crude oil per day.

The lack of visible personnel is because most plant equipment is controlled from the central control room. Now, SK Innovation is adding another “brain” beside the operators—a form of artificial intelligence (AI) that reads process data around the clock, detects subtle changes that people might miss, and suggests optimal operating conditions.

This is what SK calls the "Dual Brain." The "Brain AI" analyzes vast amounts of data to identify anomalies and propose optimized operating conditions, which engineers then review and use their field experience and context to make final decisions. Rather than a fully autonomous plant that replaces humans, this approach is designed to compensate for human temporal and physical limitations.

Changhoon Jeong, Head of the Manufacturing AI Promotion Team at SK Energy, said, "Brain AI is an engine that analyzes and makes judgments 24 hours a day without rest, while humans make the actual decisions," adding, "AX itself is not the goal; the focus is on how we address the essence of our business."

On the 10th, Changhoon Jeong, head of the Manufacturing AI Promotion Team at SK Energy, explained the direction of the artificial intelligence transformation (AX) at Ulsan CLX to reporters in a conference room inside Ulsan CLX. Photo by Seomdeumeum

The background for implementing AI at Ulsan CLX lies in the accumulated complexity of 60 years. According to Jeong, the facility integrates about 98 different processes, and the average age of equipment is 33.6 years. If the operating conditions of one process change, it impacts the production volume, quality, yield, and energy consumption of others. With a wave of veteran retirements, one challenge is converting the operational know-how stored in human experience into data and algorithms.

AI adoption is being advanced with a focus on production optimization, equipment reliability, and safety. In production, AI analyzes numerous process variables in real time to suggest optimal points. In certain processes, operators adjust conditions based on AI recommendations; where automatic process control (APC) systems are in use, AI suggestions are integrated directly into control systems.

Energy efficiency is also a key target. Steam, electricity, hydrogen, and fuel are intricately connected across multiple processes, making it difficult for humans to optimize the entire CLX. SK has already applied a total optimization model to its steam network and plans to expand the model to additional energy sources.

Equipment management is shifting from a “fix after failure” approach to early anomaly detection. The rotating machinery monitoring system "SKADI" detects concerning signs by reading vibrations and temperature changes. In safety, closed-circuit (CC) TV, drones, and robots are utilized to cover blind spots that are difficult for humans to access directly.

Currently, one robotic dog is used on-site to patrol and detect gas at Ulsan CLX. With the newly established integrated platform this year, if an anomaly signal occurs, the robotic dog moves to the site, analyzes the collected data, and communicates the findings to staff. SK is also considering expanding to around 10 robotic dogs.

Visitors listen to explanations about manufacturing AX-related exhibition content at the SK exhibition hall during the Ulsan World Future Industry Expo (WAVE2026), held for three days from the 10th at the Ulsan Exhibition Convention Center (UECO) in Ulju-gun, Ulsan. SK

A few days ago, the SK exhibition hall at "WAVE 2026" at the Ulsan Exhibition Convention Center (UECO) provided a glimpse into the future direction of the plant. Production optimization, equipment anomaly prediction, and safety AI were all unified under the "Dual Brain" operational system. While these technologies might seem futuristic, Jeong explained that a significant portion of the showcased systems is already being utilized in the field.

However, the Dual Brain is not yet a fully completed system. After technologies are verified and proven effective in individual processes, they are gradually expanded throughout the entire complex. SK Innovation aims to achieve productivity improvements of approximately KRW 100 billion per year, zero equipment downtime, and zero serious accidents by 2030.

The refinery that first lit its flames in Ulsan over 60 years ago grew through human expertise. Now, in that same plant, AI has begun reading the numbers 24/7. Yet, the final decisions in the HOU control room still belong to the operators in front of their monitors. The vision for this 60-year-old plant is not one of human absence, but rather a facility where human experience is augmented by the analytical powers and insights of AI.

This content was produced with the assistance of AI translation services.