Revamp of Feed Preheat Network Using Aspen Hysys in a Kero Hydro-Desulphurization Unit

Abstract

The paper is based on the revamp of feed preheat network in a Kero hydro-desulphurization unit. This revamp is beneficial as it does not require additional equipment to raise the feed temperature. Desulphurization of crude is a catalytic process used in oil and gas refining industry to remove sulphur content from refined petroleum products. Previously, feed was charged from the crude distillation unit at 103°C. Due to envisaged changes, the feed is now charged from storage tanks at a temperature of 40°C. This requires a higher feed heater duty or decrease in feed rate. This potential underutilization of the unit could impact the product supply from the refinery with negative financial implications. The aim is to preheat the feed at a temperature of 40°C to a temperature of 150°C prior to entering the feed heater. The methodology was to configure the feed preheat network of the unit in Aspen-Hysys as existing to validate the exchanger design with present operating condition and to reconfigure the same feed preheat network to maximise the feed temperature, whilst ensuring sufficient temperature availability at the fractionator inlet for the required performance. Based on the simulation study, it can be concluded that feed could be preheated to the optimum level by reconfiguring the existing heat exchanger network. This configuration would reduce the charge heater duty along with maintaining the required fractionator feed temperature at an optimum level. This approach requires the reconfiguration of the existing streams, without having to involve additional equipment. This paper would give insight on ways in which reconfiguration of existing preheat networks can be carried out without the use of additional equipment and also provide knowledge on methods to utilize energy sources present within the process which would lead to financial savings.

Keywords: Heat exchanger, hydro-desulphurization, Aspen Hysys, preheat network, reconfiguration