CHEMICAL ENGINEERING TRANSACTIONS VOL. 35, 2013 A publication of The Italian Association of Chemical Engineering www.aidic.it/cet Guest Editors: Petar Varbanov, Jiří Klemeš, Panos Seferlis, Athanasios I. Papadopoulos, Spyros Voutetakis Copyright © 2013, AIDIC Servizi S.r.l., ISBN 978-88-95608-26-6; ISSN 1974-9791 New Retrofit Approach for Optimisation and Modification for a Crude Oil Distillation System Dina Kamel a,* , Mamdouh Gadalla a , Fatma Ashour b a Chemical Engineering Department, British University in Egypt, Cairo11837, Egypt b Chemical Engineering Department, Cairo University, Giza, Egypt Dina.Ahmed@bue.edu.eg Crude oil atmospheric distillation units consume substantial amounts of energy, as equivalent to a 2 % of the total crude oil processed (Errico, 2009). An existing crude distillation unit is costly to modify due its complex configuration and existing limitations of structure, space area, matches, bottlenecked equipments, etc. Thus, a few new crude distillation units are built and most projects are directed to revamping existing equipments. Modifying an existing plant is a tedious task, more complex than a new process. While revamping, many parameters must be considered and structure limitations need to be met. This paper develops a new revamping method based on rigorous simulation and optimisation procedures. This method accounts for both the distillation column and the associated heat exchanger network at the same time to maximise the use of existing equipments. The methodology considers process changes and structural modifications together with the interactions between the existing distillation process and heat recovery system. The new method is valid for multiple objective functions, i.e. saving energy, reducing emissions, enhancing production capacity, and profit improvement. The new presented methodology is applied to a local atmospheric plant for MIDOR, as an Egyptian refinery case study. Many revamping options were obtained, including no structural modifications, simple additional exchanger areas, and additional units or equipments. 1. Introduction Crude distillation units (CDUs) are major energy-consuming units and therefore require extensive energy management. There are many ways to increase energy efficiency, and heat exchanger network (HEN) design and process heat integration are widely used methods. Heat transfer from hot products and pump- around streams to the crude feed by the applications of HEN reduces the energy demands of both coolers and furnaces. This reduction of energy demands diminishes the operating cost while increases the capital cost for exchanger area installation, therefore, the retrofit design is more preferable than the grass-roots design for oil refineries (Pejpichestakul, 2013). Standard objectives of revamping include increasing the plant throughput, reducing the energy demands, utilising more efficiently the raw materials, reducing the atmospheric emissions and waste generation. All these objectives preferably be fulfilled without modifying much the physical constraints of the unit, such as column actual diameter, pump-arounds and side- columns locations, exchanger matches and areas, maximum heat loads (fired heaters), etc. The interactions between the existing distillation process and heat recovery system have a critical impact on the revamping of the overall process. These interactions are the operating conditions of the distillation column, including feed preheating temperature, steam flow rate, pump-around duties and flow rates and reflux ratio, in addition to the existing exchanger matches and areas of the heat recovery system (Gadalla, 2003).Many researchers worked on revamping crude distillation units by sequential approaches i.e. column revamping then HEN or vice versa, or in simultaneous approaches with targets of Pinch Analysis (Gadalla et al., 2003). In these research works, existing heat exchanger networks were considered through their targets only and not via their matches or physical constraints. The main objective of this work is to develop a new methodology for revamping and simulation framework for heat-integrated crude oil distillation systems. This approach is based on rigorous simulation and 1363 DOI: 10.3303/CET1335227 Please cite this article as: Kamel D., Gadalla M., Ashour F., 2013, New retrofit approach for optimisation and modification for a crude oil distillation system, Chemical Engineering Transactions, 35, 1363-1368 DOI:10.3303/CET1335227