Pinch Analysis and Process Integration in Petrochemical Plant

Abstract

Energy conservation and Process Heat Integration is always been crucial concern in Petrochemical plants. Many a times utilities used in the plants are either excessive or deficit. These excessive or deficit usage of utilities are the major heat load losses which should be compensate or-else, there is maximum usage of utility, which indeed increase the operational cost of the plant and decrease the production; as production parameters gets affected quantitatively and qualitatively. To overcome these losses in petrochemical process plants, an analogy “Process Heat Integration” or “Pinch Analysis” was introduced. This analytical methodology was reviewed from generations to generations to make it handy and time saver. Various software packages related to process designing and heat integration includes such analytical software. In this project, “Online Pinch Analysis Tool” (analytical software) developed in University of Chicago, Illions, by Jeffry. S. Umbach. The process discussed in this project is about manufacturing of Linear Alkyl Benzene (LAB). The complete manufacturing process is divided into 6 units; Unit 100/200/300/400/500/600 (As per Universal Oil Products (UOP) standards). Each unit is named after the process held in it. Basically, the complete process is about separating heavy keys and lighter keys from a hydrocarbon (Kerosene: Raw material). In total, there 88 heat exchangers (Air-cooled and Tubular) analysed with the “Online Pinch Analysis Tool” software package. The analysis resulted in three sets of graphical presentation of process streams; Hot and Cold Composite curves, combined composite curve and Grand composite curve. Combined composite curve results in lowest minimum temperature difference, which is an optimal for suitable energy targets to be achieved. Grand Composite Curve will result into “Pinch Temperature” which helps in determining the minimum hot and cold utilities load required. To express the utilities load, a stream matching diagram is also presented. After completing Pinch analysis, we came to a conclusion of maximum energy saving potential in Unit 600. Energy saving potential is 17% in hot utilities and 21.17% in cold utilities. Other units also have some minimal saving which is incorporated in this thesis.