A Novel Freeze Drying Process by Using Self-Heat Recuperation Technology

Freeze drying technology produces high quality products, because a drying condition at low temperature and pressure makes less physical and chemical changes to the dried products than any other drying technology. Therefore, this technology has been gathering attention for applying not only to foodstuffs but also to pharmaceutical products. However, it is well known that freeze drying technology consumes a lot of energy. In the process using freeze drying technology, heat is added by the heater and then removed by the condenser to prevent for vapour to enter a vacuum pump, results in wasting heat into environment. Therefore, the currently available applications are not so many. Thus, to propagate this technology to the other drying processes, it is necessary to reduce the energy required for the process and to reduce the energy costs for the production. In this paper, we proposed three new freeze drying processes based on the concept of self-heat recuperation technology for energy saving and compared the energy required for them in a commercial process simulator. From the simulation results, it is expected that maximum 94 % of energy can be saved by using proposed processes.