2. Industrial and development techniques

Freeze-drying can be carried out using a variety of technologies. Sublimation can be carried out either by lowering the total pressure (vacuum freeze-drying), or by lowering the water vapor pressure in the direct vicinity of the product (freeze-drying with adsorbents at atmospheric pressure). The method for recovering the extracted water vapour then differs from case to case. A number of industrial techniques are also available to provide the heat required for dehydration.