Zhenhai Refining & Chemical applies China’s first closed coking removal technology for delayed coking

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On December 25, 2017, with the final silo cover installed and the exhaust fans operating properly, the \"safe and environmentally friendly integrated technology for closed coking, transportation, and storage\" was successfully implemented at Zhenhai Refining & Chemical Co., Ltd. This technology is the first of its kind in China; Sinopec holds multiple independent intellectual property rights, and it boasts advantages such as automation, intelligence, and clean production, with its overall technology reaching world-leading levels. Delayed coking is the main method for the deep processing of residue oil; the feed oil undergoes coking reactions in a coking tower at around 500 degrees Celsius, and the coke remaining in the tower is removed to a coke drum through hydraulic coke removal. The operators have to perform over 350 steps on the 4 coke towers every 24 hours, which makes errors likely and increases safety risks. At the same time, during processes such as coking removal, static dehydration, coking extraction, and transportation, operations like open-type coking tanks and outdoor coking extraction generate petroleum coke dust and unpleasant odors. Therefore, the process characteristics make delayed coking the most difficult and dirty unit in refineries. To improve the automation level of the equipment and achieve clean production throughout the entire process, the R&D team at Zhenhai Refining & Chemical Corporation pursued innovative solutions through diligent efforts, proposing a comprehensive technical plan for safe and environmentally friendly delayed coking processes that includes closed-system coke removal, transportation, and storage. In June 2013, the feasibility study for the plan was completed. In December 2016, the project was included in Sinopec’s “Ten Dragon Key Technology Projects”. The entire plan consists of 4 sub-projects, all of which have been successfully implemented. Building on the stable operation of the main equipment for closed-type coking removal for 3 years, on September 6, 2017, the project entered its third implementation phase, which involved covering the coking tank silos and carrying out work to treat exhaust gases. On December 22, the entire set of technologies was successfully implemented, enabling a sealed operation throughout the entire process of petroleum coke production and transportation; the overall technology has reached world-leading levels.