劣质重油浅度热裂化中试研究

Pilot Plant Test for Mild Thermal Cracking of Heavy Oil

中国石化洛阳工程有限公司(LPEC)开发了一种将浅度热裂化反应和深度热裂化反应有机结合加工劣质重油的新技术(ADCP)。该技术可显著改善延迟焦化装置的进料性质、延长加热炉的运行周期、提高液体产品的产率。为了给工业生产装置提供基础设计数据,LPEC在自建的中试评价装置上,考察了浅度热裂化反应条件对生成重油的黏度以及甲苯不溶物含量的影响。结果表明,提高反应温度或延长冷油停留时间,浅度热裂化后的重油轻质化明显,黏度显著降低。当基准冷油停留时间为"t"时,反应温度由(T-30)℃提高到(T+30)℃,减黏率由18.80%提高到89.25%;在基准反应温度为"T"时,冷油停留时间由(t-20)min延长到(t+20)min,减黏率由40.06%提高到72.86%;但过高的减黏率会加剧甲苯不溶物的生成,不利于工业装置的长周期安全运行,因此应选择适宜的操作条件,将减黏率控制在一定范围之内。

Advanced delayed coking process （ADCP）was developed by Luoyang Petrochemical Engineering Corporation（LPEC）, which integrates a mild thermal cracking stage and a deep thermal cracking stage, to improve the properties of feed, prolong the on-stream time of furnace and increase liquid product yield of delayed coking process. The test was carried out in a pilot plant to investigate the effects of reaction conditions on the viscosity and toluene insolubles content of produced heavy oil. The results showed that with the increase of reaction temperature and on-stream time prolonging, heavy oil converted markedly into light products and viscosity of heavy oil was decreased significantly. When the reaction temperature increased from （T- 30）℃ to （T＋30）℃ under the on-stream time of t min, the visbreaking rate was increased from 18.80% to 89.25%. When the on-stream time was prolonged from （t--20）min to （t＋20）min at the reaction temperature of T℃, the visbreaking rate was increased from 40. 06% to 72.86%. However, the content of toluene insolubles, which is harmful to the safe and long period operation of the industrial unit, also increased sharply with the increase of visbreaking rate. Therefore, the operating conditions of the mild thermal cracking stage should be optimized in order to control the visbreaking rate within a certain range.