Steam Drying — History and Future

ABSTRACT

The concept of steam drying originates from the mid of the last century. However, a broad industrial acceptance of the technique has so far not taken place. The paper deals with applications of steam drying within certain industrial sectors where the technique has been deemed to have special opportunities. The applications discussed involve drying of fuels with high moisture contents, cattle feed exemplified by sugar beet pulp, lumber, paper pulp, paper and sludges.

Steam drying is compared to flue gas drying of biofuels prior to combustion in a boiler. With reference to a current installation in Sweden, the energy losscs, as manifested by loss of co-generation capacity, are discussed. The energy saving potential when using steam drying of sugar beet pulp as compared to other possible plant configurations is demonstrated. Mechanical vapour recompression applied to steam drying is analysed with reference to reported data from industrial plants. Finally, environmental advantages when using steam drying are presented.

Keywords applications;:

• co-generation;
• energy efficiency;
• environmental aspects
• steam drying