催化裂化装置防结焦技术研究

Study on Ant-coking Technology for Catalytic Cracking Unit

从催化裂化工艺和实际生产出发,根据沉降器的结焦部位、焦块的形态和构成归纳出导致沉降器结焦的三大成因-湿催化剂粘附结焦、重组分油冷凝结焦和缩合反应结焦。原料油在催化剂上不能完全汽化形成湿催化剂,油浆中重组分在沉降器内以汽液两相形式存在,缩合反应生成液相的重组分,这些为结焦提供了物质基础。分析认为湿催化剂粘附结焦是提升管、旋分器料腿和沉降器内结焦的主要原因;重组分冷凝是旋分器升气管外壁、沉降器内和转油线结焦的主要原因。论述了包括原料性质、原料汽化率、油气停留时间、粗旋与顶旋的连接方式和设备的影响等五大影响沉降器结焦的主要因素,并总结提出避免或减缓沉降器结焦的措施。

Three main causes resulting in coking in settler including wet catalysts adhesion coking, heavy ingredient oil condensation coking and condensation reaction coking were proposed from catalytic cracking process and actual production aspects, based On coking site in setter and morphology and structure of coke block. Crude oil does not be vaporized totally to form wet catalyst on the layer,heavy ingredients in oil slurry are in the form of vapor-liquid phases,the condensation reaction produces liquid heavy ingredients,these provide material base for coking. The analysis thinks that wet catalysts adhesion coking is main cause for coking in riser, separator dip leg and settler,as well as heavy ingredients condensation leads to coking in separator riser outer tube wall,settler and oil transfer pipe Five factors resulting in settler coking including raw oil properties, vaporization rate, oil-gas residence time, connection of the rough cyclone and top cyclone, equipment were discussed. Measurements to prevent and depreciate settler coking were put forward.