原料劣质化对延迟焦化装置的影响分析及应对措施

Influence of Raw Material Deterioration on Delayed Cokingg Unit and the Countermeasures

某公司延迟焦化装置设计以减压渣油为原料,但按照该公司重油加工流程安排,该装置长期维持单炉室低负荷运行,并且需要掺炼催化油浆和脱油沥青进原料系统。随着催化油浆和脱油沥青掺炼比例的逐渐提高,焦化装置混合原料性质劣质化严重,原料残炭以及原料中沥青质含量屡次突破装置历史最高值,为装置带来了新的生产难题。通过对原料劣质化给装置加热炉、焦炭塔、分馏塔等系统带来的一系列操作及管理上的不利影响,以及原料劣质化后装置产品分布变化等方面进行全面而深入的分析,并结合实际生产经验,总结出日常生产期间原料劣质化时装置可采取的应对措施,同时就原料劣质化常态化下装置操作调整提出了提高反应苛刻度、防止生成弹丸焦、加强对高温特阀的管理、优化除焦操作等优化措施,为焦化装置在原料劣质化下的安全平稳运行提供了操作调整优化的方向。

The delayed coking unit of a company was designed with vacum residue as the raw material,but it had maintained low load operation of a single chamber for a long time according to the heavy oil processing process flow and needed to blend catalytic oil slurry and deoiled asphalt into the raw material system.As the blending ratio of catalytic oil slurry and deoiled asphalt increased,the properties of mixed raw materials to the coking unit were seriously deteriorated,and the carbon residue and asphaltene content of raw materials repeatedly exceeded the historical high of the unit,bringing new production problems to the unit.This paper makes a comprehensive and in-depth analysis on the operational and management impacts of raw material deterioration on heating furnace,coke drum,fractionator and other systems as well as the changes in product distribution,summarizes some countermeasures that can be taken in case of raw material deterioration during daily production combined with actual production experience,and puts forward some optimization measures for the operational adjustment of unit while raw material deterioration becomes normalization,such as improving the reaction severity,preventing the formation of shot coke,strengthening the management of high temperature special valve and optimizing the decoking operation,which provide direction for the operational adjustment and optimization of coking unit to achieve safe and stable operation against raw material deterioration.