Belghaieb J.,Energy and Environment Research Unit |
Dkhil O.,Energy and Environment Research Unit |
Elhajbelgacem A.,Energy and Environment Research Unit |
Hajji N.,Energy and Environment Research Unit |
Labidi J.,University of the Basque Country
Chemical Engineering Transactions | Year: 2010
The aim of this work is to improve heat recovery in a nitric acid production plant using process integration. The studied plant produces 1340 tons of 58 % nitric acid per day and the necessary data is taken from its current operating state. Using collected data, the simulation of the process was conducted considering that the reactions continue to occur in pipes, which are regarded as adiabatic plug flow reactors and heat exchange is achieved in counter-current multitubular heat exchangers-reactors. The simulation results allowed to establish the exergy balance of the process and to identify the main zones of energy degradation. The analysis showed that the total exergy losses in the heat recovery exchanger network are about 20 MW and its overall exergetic efficiency is about 93 %. Energy degradation was found to be primarily localized in the water-cooled condenser of the low pressure reaction and in the gas-gas exchangers. Moreover, the application of pinch technology made it possible to estimate the pinch temperature and to determine the minimum consumption of hot and cold utilities. Finally, different solutions were suggested to minimize utility consumption in the studied plant. Copyright © 2010 AIDIC Servizi S.r.l.