The well-known benchmark process for hydrodealkylation of toluene (HDA) to produce benzene is revisited in a multi-objective approach to identify environmentally friendly and cost-effective solutions. Some guidelines to develop an eco-design framework for chemical processes, involving multiple criteria to be satisfied simultaneously are proposed, based on simulation, optimization, multiple choice decision making procedures and life cycle assessment. Two studies related to the selection of the primary energy source, either fuel oil or natural gas for the utility production system (UPS) of the HDA process are conducted. In each case, a multi-objective optimization problem involving the total annual cost of the process, and five environmental burdens is carried out.