气体分馏装置重沸器结焦原因剖析

对气体分馏装置重沸器结焦物和在模拟生产工况下合成的结焦物组成、生产装置的原料及流程进行了分析。结果表明，重油催化裂化液化气中携带的脱硫剂N-甲基二乙醇胺及其降解产物与设备腐蚀产生的物质以及脱硫剂中的添加剂成分，在操作条件下，进一步聚合形成具有粘结性的聚酰亚胺类物质，附着在换热器壳程，使气体分馏装置原料携带的焦粉等固体微粒粘附于其中，造成了重沸器结焦。并据此提出了抑制气体分馏装置重沸器结焦的方法，改造后，装置已连续运转8个多月。

STUDY ON THE CAUSE OF COKING IN THE REBOILER OF A GAS FRACTIONATION UNIT

The composition analysis of the coke formed in the reboiler of a gas fractionation unit showed that it consisted of coke powder, polyimide and a small amount of sulfolane. Feed and other materials related in the process, such as desulfurization agent, n-methyldiethanolamine (MDEA), and the flow sheet of the system were investigated. Results showed that the formation of coke was resulted by the polymerization of the entrained MDEA and its degraded materials carried by the LPG stream from the heavy oil catalytic cracking unit and the materials formed by equipment corrosion to form sticking polyimide compounds fouled on the wall of the heat-exchanger; the coke power and other solid particles carried by the LPG stream were further deposited on the sticking materials to form coke. In order to validate these explanations, coke samples simulating the process operating conditions were obtained and analyzed in the laboratory. Finally, some suggestions that could reduce coking in reboiler were proposed and a prolonged operation cycle of more than 8 months was observed after applying these measures.