可调循环比延迟焦化分馏塔底油结焦倾向评价

在重油热加工性能评价装置上,以取自某厂延迟焦化装置的减压渣油、焦化辐射段进料、循环油以及经蒸馏切割得到的大于450℃重循环油为原料,对延迟焦化装置的结焦倾向进行评价实验。该装置采用中石化洛阳工程有限公司开发的可调循环比延迟焦化工艺技术,以甲苯不溶物的生成量来表征油品的结焦倾向,考察反应温度及反应时间对油品中甲苯不溶物生成量的影响,得到了4种重油在360℃下的临界结焦曲线,以及循环油在360℃和380℃下的临界结焦曲线。分析了油品性质对结焦倾向的影响。实验表明:结焦倾向与油品性质有关,在相同条件下,采用可调节循环比的延迟焦化工艺技术能减少焦化分馏塔底的结焦,从而可延长延迟焦化装置的运行周期。

Study on Coking Tendency of Main Fractionator Bottom Oil in Delayed Coking Process with Adjustable Circulation Ratio

The experiment was performed at the Heavy Oil Coking Evaluation Pilot Plant with the feed of vacuum residue, feed of coker radiation section, circulating oil and heavy cycle oil of 〉 450 ℃ from the delayed eoking unit. The process of the plant is the delayed coking process with adjustable circulation ratio developed by Luoyang Petrochemical Engineering Corporation/ SINOPEC. The amount of toluene insolubles is utilized to characterize the coking tendency of the oil. In the experiments, the impact of reaction time and temperture on the production of toluene insolubles has been studied. Critical coking curves of 4 heavy oils under the temperature of 360 ℃ are obtained as well as the critical coking curves of cycle oil under the temperatures of 360 ℃ and 380 ℃. The impact of oil properties on the coking tendency is analyzed. The results show that the coking tendency is subject to the oil properties. Under the same conditions, the application of delayed coking process with adjustable circulation ratio will reduce the coking at the bottom of fractionator. Therefore, the operation cycle of the delayed coking unit is extended.