Ian David Lockhart Bogle and Michael Fairweather (Editors), Proceedings of the 22nd European Symposium on Computer Aided Process Engineering, 17 - 20 June 2012, London. © 2012 Elsevier B.V. All rights reserved Multiobjective Optimization in Distillation with Reactor-Side for Hydrodesulfurization Process of Diesel Erick Y. Miranda-Galindo a , Juan G. Segovia-Hernández a , Salvador Hernández- Castro a , Adrián Bonilla-Petriciolet b and Gade Pandu Rangaiah c a Universidad de Guanajuato, Campus Guanajuato, Division de Ciencias Naturales y Exactas, Departamento de Ingenieria Quimica, Noria Alta S/N, Guanajuato, Gto., 36050, Mexico b Instituto Tecnológico de Aguascalientes, Departamento de Ingeniería Química, Aguascalientes, 20256, México c National University of Singapore, Department of Chemical & Biomolecular Engineering, Engineering Drive 4, 117576, Singapore Abstract The distillation reactor-side has been proposed to remove sulfur compounds of diesel. The design and optimization of a hydrodesulfurization process involve the selection of the configuration and the operating conditions to minimize the total annual cost, CO 2 emissions and the amount of sulfur compounds. In general, the optimal design of hydrodesulfurization process is a highly non-linear and multivariable multiobjective optimization problem, with the presence of both continuous and discontinuous design variables. In particular, stochastic multiobjective optimization algorithms are capable of solving, robustly and efficiently, challenging optimization problems, and they appear to be a suitable alternative for the design and optimization of complex process schemes. In this study, we have implemented a multi-objective optimization method to obtain the design and optimization of three distillation reactor-side in the hydrodesulfurization process. The results obtained in the Pareto Fronts indicate competition between total annual cost, CO 2 emissions and the amount of sulfur compounds of the hydrodesulfurization process. These Pareto Fronts are useful to identify proper conditions for the operation of this process. In general, the reduction of the amount of sulfur compounds increases the TAC and CO 2 emissions. However, we can identify operating conditions where the TAC can be reduced. Keywords: hydrodesulfurization process, multiobjective optimization, Pareto Front. 1. Introduction The design of new processes in the chemical engineering industry takes into account policies of process intensification, which can be defined as any chemical engineering development that leads to a substantially smaller, cleaner, and more energy-efficient technology. One example of process intensification is the minimization of total annual cost (TAC), which is associated with lower energy consumption, lower greenhouse gas emissions, miniaturization of process equipment, multipurpose equipment, safety operations, and others (Moulijn et al., 2008). In particular, hydrodesulfurization (HDS)