Reduction of Energy Consumption in the Process Industry Using a Heat-Integrated Hybrid Distillation Pervaporation Process

Abstract

In the present work, the advantages of using heat integration in a hybrid distillation pervaporation process are studied and, on the basis of the developed model, the industrial applicability of the process is analyzed. The basic idea of the heat integration is to condense the distillate stream in a heat-exchanger pipe inside the membrane. The condensation energy is directly released into the process, not needing external heat exchangers to preheat the membrane feed. This is reflected in an important reduction in the process energy consumption. Experimental work has been carried out in order to characterize the membrane and to prove the positive influence of the heat integration. A rigorous model for the pervaporation process has been developed and validated. Additionally, simulation studies take place in order to compare the energy supply in the proposed process with a typical industrial process layout. As a result, in comparison to the results of Sommer and Melin [Sommer, S; Melin, T. Ind. Eng. Chem. Res. 2004, 43, 5248-5259], energy savings of 44.7% can be achieved. Further study has been realized in order to prove the reduction in the specific separation costs. The operation conditions have been varied, finding always lower specific separation costs in the heat integrated case. In the optimal operation point, the reduction reaches its maximum value of 20%.