Initial analysis on heat exchanger networks of fatty acid fractionation plant to optimize energy recovery and controllability

Abstract

The objective of this paper is to present the initial analysis on the energy recovery and controllability of the existing heat integrated fatty acid fractionation plant. From this initial analysis, the existing heat integrated fatty acid fractionation plant is analysed to know the either the existing heat exchanger networks (HENs) satisfied the design criteria, or controllability criteria by using trade-off plot. According to the trade-off plot, if the existing HENs is better in terms of design criteria, then more efforts need to be invested to control the network. On the other hand, if the existing HENs is better in terms of controllability criteria, then more efforts need to be invested to reduce the energy consumption. In this study, the initial analysis means the value of the ΔTmin used for the current HENs is investigated and the controllability of the network is predicted by using trade-off plot. In order to investigate the value of the ΔTmin used for the current HENs, only the first two stages of the model-based flexible and operable HENs is used. In the Stage 1, the value of the ΔTmin is investigated by selecting the value of the ΔTmin ranging from 10 °C to 40 °C with the increment of 10 °C. Then, HEN is synthesized for the selected value of the ΔTmin. Once the networks have been synthesized, all candidates are transferred into a process simulator to test their process feasibility in Stage 2 where the unfeasible candidates will be eliminated. Then all feasible candidates will be predicted in terms of their controllability performance by using trade-off plot. Energy integrated fatty acid fractionation plant is used as a case study for this initial analysis. This paper only considers steady state controllability test without considering process dynamics