Application of process integration techniques in sugar industry by-product plants

Objective: The facilities for the production of ethanol and CO2 in the byproduct company have a high level of energy consumption. This implies a low economic performance of the processes and therefore requires the implementation of energy integration schemes using Pinch technology. Materials and Methods: Two cases were analyzed: the independent ethanol production plant (Case A) and the combination of ethanol/CO2 plants (Case B). New configurations for the current exchange networks were determined based on the minimum energy requirements of the process using the Aspen Energy Analyzer software. Alternatives that decrease utility consumption were proposed based on available energy resources and program tools. An economic evaluation of the proposed designs was performed. Results and Discussion: The alternatives represent savings from 24% to 78%. It was determined that the incorporation of stillage to replace the current heating utility is the most economically feasible investment with a savings of $1,252,120 USD/year. Conclusion: The application of Pinch analysis allowed for new configurations of heat exchange networks that represent a greater commitment to optimal designs.