Energy reduced in spray drying research
As part of an industrial joint research (IGF) project in Germany, a research team from University of Hohenheim has set the goal of significantly reducing the energy required for spray drying.
The focus of the work at the German university is the use of superheated steam to enable the recovery or further use of enthalpy of evaporation through steam condensation. In particular, it is looking at the design of the flow guidance in the spray tower as well as a quick discharge of the powder from the high temperature zone.
It also plans to investigate the effects of the increased temperature load and drying speed on the product quality compared to conventional spray drying.
An average of around 400,000 tons of skimmed milk powder is currently spray-dried in Germany each year in the dairy industry. If this amount is taken as a basis, it can be assumed that at least twice the energy savings potential for food powder in general.
With 400,000 tons and a dry matter content of 50% in the spray solution, there is a potential savings of several kilotons of carbon dioxide emissions per year. According to calculations, this would be around 20kt of carbon emissions equivalent per year for skimmed milk powder alone (based on natural gas as an energy source when using a combined heat and power plant) and correspondingly to approximately 40kt carbon emissions per year for the entire German food sector.
Since only the enthalpy of evaporation was taken into account in these calculations, there would be additional savings in the area of exhaust gas losses, compared to the current standard, which is offset by increased process implementation.