INFLUENCE OF DISTILLATION COLUMN SEQUENCING ON MINIMUM VAPOR FLOW- CASE STUDY: OLEFIN PLANT

In the steam cracking processes, the cracked gas is liquefied for purification so it is moved to the fractionation system and separated by distillation columns that are commercialized using various sequences. The present study focuses on choosing the best distillation sequence for the separation of a multi-component mixture based on calculating the minimum vapor flow (MVF) of the mixture which has not been investigated for an olefin plant up to now. The stream enters into cold section of a typical steam cracking (olefin) petrochemical plant has been considered for the case study that has been lumped into 5 key components. It was found that the direct demethanizer front-end sequence results in the lowest rate of total MVF compared to the other studied sequences that could be due to the higher rate of lighter components in the cracked gas. The other commercial olefin licences such as front-end de-ethanizer and front-end depropanizer are also compared with the above-mentioned sequence. The different scenarios were studied using HYSYS simulation software.

Keywords:

distillation columns , minimum vapor flow , olefin plant , sequencing