Retrofit of low-temperature gas separation section of an olefin plant

Retrofit and optimization of low-temperature gas separation processes is a challenging task owing to complicated interactions between the core process (separation columns), refrigeration cycles, and the associated heat exchanger network. In this paper, the performance of cold section of an olefin plant is optimized. A comprehensive screening of all effective changes using genetic algorithm suggests some retrofit modifications. Having incorporated the best operating column parameters along with available refrigeration levels, a 11.3% improvement in utility cost was achieved.