Clean and Green: Fraunhofer ISE at the IFAT Trade Fair
The IFAT, the world’s leading trade fair for water, sewage, waste and raw materials management, is being held in Munich, Germany from May 14 – 18. About 3100 exhibitors and more than 130 000 visitors are expected to attend. The Fraunhofer Institute for Solar Energy Systems ISE is presenting their innovations for clean water at a communal booth together with the Fraunhofer Alliance SysWasser and the Solar Spring GmbH (Hall B2, Booth 215/314).
Membrane-based Air Humidifier
The device uses a microporous hydrophobic membrane to humidify dry air in a controlled and hygienic manner. Due to the differing water partial vapor pressure, the water vapor permeates out of the liquid film through the membrane and is absorbed by the dry air. The system can be used to humidify air in private homes, in industrial environments but also in art museums, for example. Besides its low energy consumption and excellent controllability, the device also maintains high hygienic standards, since the membrane is also effective against bacteria and no wet surface comes into contact with the air flow.
Desalinization and Alkaline Treatment Through Membrane Distillation
Membrane distillation systems can be used to desalinate sea water to provide potable water. In addition, they also can be used to concentrate industrial lyes and thus purify water or extract valuable materials, to reduce waste water or to remove volatile particles from aqueous solutions in the process industry. The systems are resistant to salt and corrosion, have very low energy consumption (<< 1 kW/m³) and use low-grade waste heat as driving energy. They produce very clean water and are characterized by an extremely flexible and dynamic operation.
Solar-driven Off-Grid Desalination and Purifying Systems
Photovoltaic-powered reverse osmosis systems provide autonomous solutions for treating sea and brackish water on remote islands or for decentrally located settlements. The reverse osmosis system can function as a flexible load in island grid systems that have a high share of renewables, thereby replacing batteries. In remote regions, electrified ultrafiltration systems can be used with off-grid PV systems for treating surface and ground water; thus making it possible to provide clean drinking water to regions that have a weaker infrastructure. By using renewable energy for sea water desalination, the global desalination capacity can be increased in the middle to long term without further increasing the carbon dioxide emissions.
Removing Acids with Membrane Distillation and Diffusion Dialysis
The combination of diffusion dialysis and membrane distillation can be used to recapture acids from e.g. pickling, galvanization and rinsing baths. The recaptured acids have a high level of purity. The waste water, now free of acids, is cleaned in a further step. With membrane distillation, the water is again made suitable for industrial use. Highly aggressive, corrosive acids that are dangerous to human health can be treated using this process. Because the concentration gradient is the driving force, no operating energy is needed for the diffusion dialysis process. For the membrane distillation process, only low calorific waste heat is required.