Abstract:

The propylene products produced by delayed coking units are limited by their own process conditions, and conventional gas fractionation processes cannot meet the requirements for polymerization grade propylene. The high content of impurities such as sulfur and water in propylene products affects the catalyst activity of downstream polyolefin unit and cumene unit, and cannot be directly used as feedstock for chemical units. By fully leveraging the advantages of integrated refining and chemical projects and utilizing the existing unqualified propylene recycling process in the ethylene unit, a new delayed coking propylene recycling process is added to the ethylene unit. Compare and analyze the operating conditions of propylene outlet of the delayed coking unit and unqualified propylene recycling points of ethylene unit, and ensure that they have the conditions for direct recycling. Delayed coking propylene is recycled to the fourth section inlet of the cracking gas compressor of the ethylene unit, and then separated from the propylene tower through alkali washing tower, dryer, and C₃ hydrogenation reactor. After refining, it meets the requirements of polymerization grade propylene, achieving the integration and optimization of refining and chemical processes. The implementation of the project has brought considerable economic benefits to the enterprise.

Key words: delayed coking unit, propylene refining, polymerization grade propylene, ethylene unit, propylene recycling, economic benefits

摘要：

延迟焦化装置生产的丙烯产品受自身工艺条件限制，采用常规气体分馏工艺无法达到聚合级丙烯的指标要求，丙烯产品中硫、水等杂质含量高，影响下游聚烯烃装置及异丙苯装置催化剂的活性，不能直接作为化工装置的原料。通过充分发挥炼化一体化项目的优势，在乙烯装置现有的不合格丙烯回炼流程基础上，新增延迟焦化丙烯至乙烯装置的回炼流程。对比分析延迟焦化装置丙烯出装置和乙烯装置不合格丙烯回炼点操作条件，可看出延迟焦化丙烯具备至乙烯装置直接回炼的条件；延迟焦化丙烯回炼至乙烯装置裂解气压缩机四段入口，经碱洗塔、干燥器、C₃加氢反应器后至丙烯塔分离，回炼精制后达到聚合级丙烯的要求，实现炼油与化工的流程整合优化，项目实施后给企业带来了比较可观的经济效益。

关键词: 延迟焦化装置, 丙烯精制, 聚合级丙烯, 乙烯装置, 丙烯回炼, 经济效益