Eco-efficiency analysis and intensification of the monochlorobenzene separation process through double-effect strategy

Distillation is an energy-intensive operation with high capital and operational costs. For this reason, intensification technologies have been developed to significantly reduce the energy usage, utility costs, and carbon footprint of modern chemical plants. In this work, a double-effect intensification strategy with heat integration was proposed for an industrial-scale monochlorobenzene separation process that can be used in a retrofit design. The conventional process and the intensification configurations were designed by simulation in UniSim software. A utility plant with cooling water and steam generation sections was also considered for realistic results regarding water consumption, CO₂ emissions, and utility costs. Additionally, in order to establish a qualitative and quantitative overall analysis, such indicators were grouped in a joint evaluation method using the Comparative Eco-Efficiency Index. The proposed configuration provides savings of 60.15 % and 61.79 % in energy and water consumption, respectively; therefore, savings of 60.15 % and 60.20 % in CO₂ emissions and utility costs were achieved, respectively, which increased the process's eco-efficiency by 84.57 % and decreased the TAC criterion by 29.65 %. Thus, the new design prove to be a convenient strategy since it significantly improved the original process performance in alignment with the United Nations’ Sustainable Development Goals.