• Energy Research
• physical sciences close
• BR close
• Portuguese close

This research investigated the use of exhaust gas recirculation (EGR) process to recover part of the thermal and chemical energy left in the exhaust boiler stream. A theoretical analysis of energy conversion and use was performed based on a small boiler, in which were performed several measurements and analysis of the operation reports, which provided the boundary conditions and relevant information for modelling the processes. The methodology considered the radiation from exhaust gases, thermodynamics balances, and economic engineering calculations for the energy recovery analysis. Financial results indicate that the exhaust gas recirculation process implementation, regarding 20% of EGR ratio, presented 69% and 1.45 years of internal returning rate and payback, respectively. However, the regenerative process presented internal returning rate and payback values of 112% and 0.9 years. Indeed, both process might be applied, in order to increase the efficiency and reduce the emissions. In this way, the implementation of the exhaust gas recirculation process can contribute to the development of more economical practices in the industry, while promoting the reduction of operating costs and improving boiler efficiency.