Chemical processes analysis and improvement

Abstract

This chapter presents the application of the exergy analysis to assess the industrial acetaldehyde production by ethanol partial oxidation. With the conclusions of such assessment, an improved plant configuration is proposed in order to use more efficiently the required process thermal exergy. A model was developed to predict all relevant thermodynamic properties of the process streams. The vapor phase was considered ideal, while the nonideality on liquid phase was corrected by Wilson equation. The exergy analysis indicates that the irreversibilities are mainly produced in the oxidation reactor (458 kW), the waste heat boiler (118 kW), the acetaldehyde absorption tower (105 kW), and distillation tower (247 kW). The improved proposed configuration decreases the overall irreversibility rate to 925 kW, which represents a reduction of 14.7 %. The modifications were made in the absorption and distillation towers and a new heat exchanger network caused a reduction of 28 % in the thermal load of the plant.