Retrofit of heat-integrated crude oil distillation columns

Engineering projects to increase the capacity of existing heat-integrated crude oil distillation columns are commonplace. Retrofit projects aim to exploit the processing capacity of existing units by changing operating parameters and/or modifying equipment. Operational modifications can be effective and usually incur little capital expenditure, but equipment changes may also be needed to achieve retrofit objectives. Existing retrofit methodologies for crude oil distillation systems mainly focus on increasing heat recovery, increasing crude oil throughput and/or increasing the yield of most valuable products by optimising column operating parameters. However, methodologies that also consider hardware modifications are lacking. The present work proposes a systematic retrofit methodology based on distillation column and heat exchanger network (HEN) simulation. Hydraulic correlations are used to consider replacing existing distillation column internals with high-capacity trays and/or structured packings. Industrially relevant case studies illustrate the benefits of the proposed methodology to analyse and assess hardware modifications for the retrofit of distillation systems when increasing capacity.