气体分馏装置丙烯回收优化及双塔流程可行性研究

 针对气体分馏装置丙烯收率低于95%的现状，运用PRO/II软件对某0.2 Mt/a气体分馏装置进行全流程模拟，通过对设计进料和不同组成的进料进行模拟，验证了模拟方法的可靠性，分析了丙烯损失的原因及提高丙烯收率的措施。结果表明，丙烯损失主要来源于脱乙烷塔塔顶气相采出和丙烯精馏塔釜液夹带，其中前者占丙烯损失的65%以上。探讨了取消脱乙烷塔，实施气体分馏双塔流程的可行性，其关键在于要控制气体分馏装置原料中C2的摩尔分数不大于0.10%。模拟数据表明，通过采用气体分馏双塔流程和优化丙烯塔操作，气体分馏装置的丙烯收率可以达到99%以上。

OPTIMIZATION OF PROPYLENE RECOVERY IN GAS FRACTIONATION UNIT AND FEASIBILITY STUDY OF ADOPTING DUAL-TOWER PROCESS

Since the recovery rate of propylene in gas fractionation unit was usually less than 95%, a simulation of the whole processing scheme for a 0.2 Mt/a gas fractionation unit was carried out using PRO/II software to study the causes of propylene loss and the countermeasures. Feeds with various compositions including design value were used in simulation and the reliability of simulation was validated. Results showed that the loss of propylene mainly came from the top outlet gas of deethanizer and the bottoms of propylene fractionating tower, in which the former occupied more than 65% of the total propylene loss. Feasibility study of eliminating deethanizer and using dual-tower process was carried out. It was found that if the mol content of C2 in feed could be controlled to less than 0.10%, the dual-tower process could be realized. Simulation data showed that with the adoption of dual-tower process and optimizing the operation conditions of propylene fractionating tower, the recovery rate of propylene in gas fractionation unit could reach more than 99%.