Biomaterials, superheated steam-drying

Chapter 3 Superheated steam drying of foods and biomaterials Chapter 4 Intensification of fluidized-bed processes for drying and formulation Chapter 5 Intensification of freeze-drying for the pharmaceutical and food industries... 

Superheated steam drying at atmospheric (or near atmospheric) pressure is the process that has been most extensively studied compared to SSD at other pressure ranges - that is, at a pressure higher or lower than the atmospheric pressure. In this section, some examples are given to explain the consequences of SSD, from both the drying (heat/mass transfer) and product quality changes points of view. This overview will be limited to foods and biomaterials, and hence will exclude products such as wood, paper, ceramics, sludge, coal, and peat that can also be dried in a superheated steam environment. 

Superheated Steam Drying of Foods and Biomaterials [Pg.97]

The basic fiindamentals of both conventional atmospheric-pressure Superheated steam drying and more novel low-pressure Superheated steam drying are presented in this chapter. The application of these processes to the drying of a wide variety of foods and biomaterials is illustrated and discussed, with emphasis placed on the use of LPSSD to preserve or even improve the properties of the drying materials. 

Kittiworrawatt, S., Devahastin, S 2009. Improvement of a mathematical model for low-pressure superheated steam drying of a biomaterial. Chem. Eng. Sci. 64 2644-2650. 

Since atmospheric-pressure (or near atmospheric-pressure) SSD involves the use of a high-temperature drying medium (i.e., superheated steam at a temperature higher than 100 °C), this type of process may not be appropriate for heat-sensitive materials such as fruits, vegetables, herbs and spices, and many other biomaterials. For this reason, an alternative drying technique has been developed to combine the advantages of SSD with an ability to conduct drying at a lower temperature. The proposed alternative is based on the fact that water vaporizes at a lower temperature if the pressure of the system is lower superheated steam can then be produced at a lower temperature under such a lower pressure. 

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