Green H2O from any source
The need for sustainable manufacturing processes is now a core component of regulatory requirements in many countries around the world and requires water process operators to minimize or fully treat wastewater streams. The solution is minimum liquid discharge (MLD) or zero liquid discharge (ZDL). Systems based on these concepts make water reusable, thereby conserving scarce water resources. At the same time, they separate material residues, for example salts, so that they can be disposed of or recycled safely. Terrawater HDH was specially developed for these requirements.
How Terrawater HDH works
Terrawater HDH (humidification dehumidification) is based on a thermal separation method. A carrier gas, generally air, is brought into contact with the salt water to be treated in a humidifier. In the process, the air becomes saturated with water vapor, while the dissolved salts remain behind in the water. Then, the moist air is conveyed into a dehumidifier. Here, the water vapor condenses on cooled surfaces (e.g. surfaces of a heat exchanger) over which cooler water flows. This results in two separate streams: pure distillate and concentrated brine. Depending on the application, the system can be operated in a closed air circuit for maximizing the thermal efficiency or in an open circuit.
Stable even with high salt loads
Terrawater HDH
By integrating the tried-and-tested Taprogge cleaning technology, water that is prone to scaling and with high salinity can be concentrated up to just short of the saturation point. In contrast to conventional desalination methods, Terrawater HDH does not use any additional chemicals for managing fouling and scaling. This ensures consistently high plant availability and significantly reduces the maintenance workload. At the same time, the use of waste heat from nearby processes as an energy source lowers the operating costs and improves the environmental footprint of the end-to-end process.
Operational benefits
The main advantage of the Terrawater HDH method is its robustness and the use of cost-free waste heat as the energy source. As the system works at relatively low temperatures, weak waste heat flows at temperatures of from 50°C to 100°C from nearby processes are sufficient – for example waste heat from engines, for which there is often no other viable use. It is often also available free of charge. In off-grid applications, solar thermal heat is also an ideal energy source. What’s more, the system works at ambient pressure and not in a vacuum, meaning that complex vacuum technology can be dispensed with and both operation and maintenance remain simple and robust.
Applications ranging from seawater to industrial wastewater
Terrawater HDH offers a particularly stable and energy-efficient solution for the desalination of seawater or brackish water, the reduction of wastewater streams from desalination (brines), or the minimization of industrial wastewater as part of an MLD or ZLD strategy. The system uses the natural principle of evaporation to separate water from dissolved salts. It combines the tried-and-tested TerraBasic and TerraPreCon technologies in a single product line.
Applications
- Seawater and brackish water desalination
- Concentration of process solutions and brines
- Concentration of brine streams from desalination (MLD/ZLD)
- Concentration of industrial wastewater
- Pretreatment for ZLD systems (e.g. in combination with Terrawater Saline)
- Closing industrial water circuits
