Seven hundred days and nights forging the “coke-making” spirit: Innovation breaks through to overcome the “cycle” — A documentary on how Guangdong Petrochemical’s delayed coking unit set a new record for ultra-long-term operation

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On January 26, 2026, as the first rays of dawn illuminated the Guangdong Petrochemical complex located on the coast of the South China Sea, the delayed coking unit continued to operate with great momentum. On this day, the facility reached a milestone: it operated safely and steadily for 750 consecutive days, successfully breaking the long-standing curse in the industry of having to replace the catalyst and carry out maintenance once a year. By developing a \"smart brain\" for precise temperature control, creating a \"multi-layered monitoring\" system that enables collaboration between humans and machines, and overcoming the core technical challenges associated with online coking without interrupting production, Guangdong Petrochemical has forged a new path for processing low-quality heavy oil—one that features safety, efficiency, and long-term operational stability. Smart refining: A transformation from a \"flame mountain\" to a \"constant-temperature chamber\". Delayed coking units are used to process what is considered the toughest feedstocks in the refining industry – low-quality heavy oils with high sulfur, high residual carbon, and high metal content. Such raw materials are like \"concrete in the oil refining industry\" – they have high viscosity and poor fluidity, and tend to coking at high temperatures, which severely limits the operating cycle of the facilities. Under the traditional mode, the furnace tubes in the heating furnace are like walking through a \"Mountain of Flames,\" making local overheating and coking inevitable. Faced with this common challenge in the industry, Guangdong Petrochemical Refining Unit 1 chose to overcome it through intelligence. The team adopted the concept of \"molecular refining\" to develop a high-precision digital twin system, equipping the facility with a \"smart brain\". This digital system is capable of providing a comprehensive simulation of the combustion conditions of the 128 burners in the furnace, as well as enabling optimization on a millisecond scale. Zhao Rui, manager of Refinery No. 1, made a vivid analogy: “It’s like having a tireless flame-adjustment expert assigned to each burner, making precise adjustments around the clock.” ”In practical operation, this digital twin system automatically adjusts the valve opening every 10 seconds, and operators verify the implementation status three times a day, thus creating a strict control loop. Through this temperature control precise to the \"capillary\" level, the temperature difference across the furnace cross-section is strictly kept within ±5°C, while the axial temperature difference is reduced to below 10°C, thereby completely eliminating the local hot spots that cause coking. This “temperature revolution” has brought about comprehensive improvements; the thermal efficiency of the heating furnace has risen from 90.5% to 93%, reaching a leading level among similar installations in the country. The fuel gas saved each year is equivalent to the annual gas consumption of a small town’s residents. More importantly, a reliable \"constant-temperature armor\" was installed around the furnace tubes, thereby preventing coking from forming at its source. Thus, the foundation for the long-term operation of the device is established. Three-dimensional prevention and control: A \"thick network\" to safeguard equipment health. Equipment health is essential for long-term operation. To ensure absolute safety, Guangdong Petrochemical has established a comprehensive three-dimensional monitoring system that functions like a thorough network, enabling a fundamental shift from reactive maintenance to proactive prevention. The online monitoring system is like a \"never-blinking sentinel\". It consists of a series of high-precision sensors that are cleverly installed in key areas of the heating furnace, such as the surface of the furnace tubes and inside the furnace chamber, enabling them to continuously detect even the slightest fluctuations in the temperature of the furnace tube surface around the clock. The data collected by the sensors is transmitted in real time to the monitoring center via a high-speed network, where advanced monitoring software performs real-time analysis and processing of the data. Upon detecting abnormal temperature fluctuations, the system can issue millisecond-level warnings immediately to inform operators to take action promptly. “This system establishes a three-level early warning mechanism: a yellow warning is triggered when the temperature rises by 3°C within 10 minutes, and a red warning is issued when the rise is 5°C; relevant information is instantly sent to the DCS control system as well as the mobile devices of maintenance personnel. The regulations require that any alert must be addressed within 30 minutes to ensure that issues are resolved without delay. ”explained Li Yuanping, the process engineer. Meanwhile, the manual inspection team acts as “experienced detectives”. Each engineer has their own inspection points, and every team is equipped with high-precision infrared thermal cameras to conduct a \"full-body scan\" of each heating furnace tube. A comprehensive “inspection” is carried out once a week, focusing on high-risk areas such as elbows, supports and hangers, and the furnace bottom section. All test data is uploaded to the intelligent analysis platform, where the system automatically generates trend analysis reports to provide a scientific basis for decision-making. During a routine inspection in November 2025, an infrared thermal imager detected abnormal data: although the local temperature of one of the furnace tubes did not reach the alarm threshold, it showed a steady upward trend for 5 consecutive days. The technical staff promptly organized an analysis and adjusted the combustion conditions in that area, successfully preventing a potential localized coking incident. This concept of \"preventing problems before they arise\" is precisely what ensures the long-term stable operation of the device. Technical breakthrough: Online coking removal breaks the industry rule that \"coking removal requires shutting down the plant.\" This used to be an insurmountable technical constraint for delayed coking units. Every coking cleaning process means a shutdown of the entire plant, resulting in significant economic losses. Guangdong Petrochemical is determined to challenge this tradition. After three years of technical research and more than a dozen rounds of solution optimization, Unit 1 of the refinery established a PR team that successfully mastered the core technology for online coking removal. This technology is known as \"minimally invasive surgery\"; it enables the gentle and controlled removal of initial fouling on the inner wall of the furnace tubes while the device is operating normally. 72 hours prior to each coking cleaning operation, the process team prepares a detailed \"Online Coking Cleaning Operation Plan\", specifying the control ranges for key parameters at various stages, and organizes training for all staff. During the operation, by precisely controlling the three-stage process of \"rapid heating – constant temperature – rapid cooling\", along with a scientifically formulated special coke-cleaning water, the coke layer is effectively removed while ensuring the safety of the furnace tubes. “What makes us most proud is that throughout the coking process, the load on the main unit remained above 90%, with fluctuations in the key process parameters being less than 3%, resulting in minimal impact on the downstream units. ”Shi Jian, the deputy manager in charge of device production, explained. The team has also developed an innovative intelligent coking prediction model. By integrating the properties of raw materials, operational parameters, and historical data, this system is able to dynamically predict coking trends and accurately recommend the optimal timing for coking removal. To date, the unit has successfully carried out 7 online coke removal operations. The average coke removal cycle has been extended from the traditional 70 days to over 100 days, completely transforming the unit’s operating conditions. 750 days of continuous operation is not just a figure representing time; it is also a reflection of technological innovation, management improvements, and the hard work of the team. On this unconventional path, Guangdong Petrochemical has achieved remarkable results: it has processed nearly 6 million tons of low-quality heavy oil in total, with various technical and economic indicators continuing to improve, and its safety and environmental performance steadily rising.