Watersolutions receives Desertec Award

The paper, which describes a project in El Gouna, Egypt that uses CSP and Low Temperature Distillation (LTD), was co-authored by Mark Lehmann, Chief Technology Officer of Watersolutions AG and Johannes Wellman, Karl Neuhäuser and Frank Behrendt of the Technische Universität Berlin.The Award was presented at the 3rd Annual Dii Desertec Energy Conference, which took place 7-9 November in Berlin, Germany. The paper was one of only four selected from approximately 60 submissions. The jury comprised experts from Dii and from the DESERTEC University Network.The paper presented the model of the cogeneration process of a simplified concentrated solar power (CSP) plant with innovative low temperature desalination. The low-temperature distillation system (LTD) was developed by Watersolutions AG and was first tested in a full-scale plant in El Gouna, Egypt, using waste heat in the cooling cycle from diesel generators at 70-85°C. Through analysing the measurement data of this demonstration plant, it was possible to derive the thermal and electrical behavior of this plant. This allowed the development of a simulation where the low-temperature distillation system was connected to the steam condenser of a CSP power plant.The Technische Universität Berlin, which has a campus in El Gouna, has been following the actual test program at the plant that evaluated the robustness of the LTD process both under normal operating conditions as well as under extreme variations in key input factors (waste heat and salinity). The plant, with a design capacity of 500 cubic metres per day (m3/d), has proven the principle, with very pure water being produced reliably and efficiently. The program verified key parameters including the following:

  • The LTD plant could manage very high salinity - up to 200,000 ppm, and was consistently operating at 80-100,000 ppm.
  • Depending on the amount of waste heat available, the plant could operate at 10-110 % of capacity, thus confirming part-load flexibility.
  • With a small amount of anti-scalant, the process worked without scaling even for higher salinities, even though the feedwater had very high gypsum content.
  • The plant with 2 stages confirmed the low electricity usage.
  • The plant could be shut off and easily restarted without any extensive process.