Process Integration for Food Drying with Air Dehumidified by Zeolites

Abstract

Zeolites have potential to increase efficiency of medium-temperature drying in the food industry. This work concerns the comparison between conventional dryers and dryers using air dehumidified by zeolite. Steady-state mass and energy balances have been used and the work concerns drying temperatures ranging from 52 to 70°C. Process integration based on pinch analysis has been applied and nine different heat exchanger networks for energy recovery are compared. Results indicated that dryers using air dehumidifier by zeolites are 10–18% more efficient than conventional dryers.

Keywords:

• Adsorption
• Energy efficiency
• Process integration
• Zeolite drying

ACKNOWLEDGEMENT

This work is supported by the staff training program (TPSDP) of the Chemical Engineering Department of the Diponegoro University, Semarang, Indonesia.

Notes

*Based on wet flow; e.g., A _ad−in  = F _a (1 + Y _{a, in} ).

*Based on wet flow.

*Heat required to increase air temperature for drying.

**Heat required to increase air temperature for regeneration.

*Combining fresh air with stream 13.