Prospective Evaluation of Spent Sulfuric Acid Recovery by Process Simulation

Abstract

This study presents the steady-state simulation and optimization with regard to the recovery of spent sulfuric acid. Our purpose was to prove the utility of process simulation in terms of designing with special materials using energy-efficient methods. Process simulation is used in order to compare technological variants, analyze technological problems that occur as well as optimize the process. In this investigation three concentration processes are compared: azeotropic distillation and multiple-effect evaporation both in co-current and counter-current modes. The main aspects of the comparison are energy consumption and heat efficiency. Process simulation is an adequate tool for analyzing the thermal decomposition of sulfuric acid, the presence of sulfuric acid in the vapor fraction, and the costs of applying a third agent. Here, three models and a simulation-based prospective evaluation of energy consumption and the economy are presented. It is shown that the process of azeotropic distillation consumes an extremely large amount of thermal energy which seems to be more than that consumed by single-effect evaporation, while triple-effect evaporation in the counter-current mode was found to be the most thermally efficacious.