[Haichuan Chemical Salary News] The ethylene-propylene cracking furnace in Yulin Energy Chemical’s DCC unit has been operating continuously and stably for 107 days

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Since October 1, 2018, the propylene and ethylene cracking furnace of the DCC unit has been operating at full capacity and with high efficiency for 107 days, which is 17 days longer than the previous operating record. During this period, approximately 2,010 tons of DMTO ethane were processed, around 34,740 tons of DCC recycled ethane, and about 15,750 tons of DMTO and DCC propane. In total, approximately 22,580 tons of ethylene and propylene were produced, laying a solid foundation for the olefin facility to reach its production targets. Faced with the demanding challenges of production targets, the management team of the DCC unit worked together as one to overcome difficulties, effectively extending the operating cycle of the propylene and ethylene cracking furnace unit and ensuring the successful completion of the production goals set by the company. The propylene cracking furnace process has a complex flow structure, stringent requirements for operating parameters, and a high degree of risk. The cracking feedstocks, ethane and propane, must be subjected to low-pressure steam at a temperature of over 830°C, with a residence time of less than 0.1 seconds, and pass through a furnace at a temperature of over 1100°C to ultimately undergo reaction and produce ethylene and propylene. High-temperature operation imposes extremely high requirements on the material of the furnace tubes, and excessive operational fluctuations can lead to accidents. Under such severe operating conditions, plant management technicians went to the site to study the process principles and parameters, and developed a set of operation guidelines based on scientific principles and practical value, which opened up a way to extend the operational life of the ethylene-propylene cracking furnace. Stably control the feed rate, feed temperature, and the ratio of ethane to propane ； The COT (reaction temperature) is strictly controlled at 832°C ±2℃ ； Increase the proportion of diluted steam injection (from DS/HC=0.3 to DS/HC=0.39) ； Adjust the damper opening to an appropriate level; it is strictly prohibited to allow the flame to burn unevenly and directly hit the furnace tubes, as well as to increase the flue gas temperature (from 130°C in the original design to 138°C). While strictly adhering to the above regulations, operators must firmly establish a \"red-line awareness and bottom-line mindset.\" They should also maintain a meticulous work attitude, actively engage in the exchange of work experience, learn from one another, and continuously improve their operational skills, so as to ensure the safe, stable, long-term, efficient, and optimal operation of the propylene and ethylene cracking furnaces. (Chen Dingling, Gao Ligui)