影响气体分馏装置丙烯收率的原因和解决措施

分析了600 kt/a气体分馏装置丙烯产品收率低的原因，通过丙烯塔检修，较大程度地提高了装置处理量，最大可达90 t/h；经过技术改造，将脱乙烷塔塔顶高压瓦斯气排放线连接至柴油加氢装置吸收脱吸塔富气进料管线上，最大程度地减少了丙烯的浪费，每天回收丙烯约2.88 t，可实现经济效益约768万元/a；对气体分馏装置采用先进控制系统，优化了丙烯塔操作，缩小了丙烯塔塔底温差，提高了丙烷产品纯度，进一步提高了丙烯收率。通过以上3项举措，减少了丙烯的排放浪费，最大程度地提高了气体分馏装置的丙烯收率。

FACTORS AFFECTING YIELD OF PROPYLENE IN GAS FRACTIONATION UNIT AND MEASURES

The reasons of lower yield of propylene in gas fractionation unit were analyzed. Revamping measures were adopted based on the analysis. After revamping, the handling capacity of the fractionator is raised to 90 t/h. The revamping measures include: (i) connecting the high pressure gas discharge line on the top of deethanizer to the feed line of absorption-desorption tower of diesel oil hydrogenation unit, which reduces the discharge of propylene furthest and recovers propylene about 2.88 t/d with an benefit about 7.68 million yuan annually; (ii) using an advanced control system for gas fractionation unit to optimize the operation of propylene rectification tower, which reduces the temperature difference at the bottoms of the propylene tower, improves the purity of propane, and increases the yield of propylene. Through the above three measures, waste of propylene emissions is reduced and the propylene yield of the gas fractionation unit is increased to a great extent.