Flash drying is a common method for wastewater sludge drying
developed in the 30 s in the US. It was devised for algae drying to
achieve rapid removal of moisture by spraying or injecting a mixture
of dried and wet algae into a hot gas stream (Shelef et al.,
1984). The turbulent hot gases serve as a carrier for mass transfer
of moisture from algae slurry to the gases. The cost of drying and
the final algal product quality are greatly influenced by the hot
gas source. Uncontaminated waste steam could lower the processing
cost and ensure a good quality final product.