- Access to freshwater is vital for human development. In more and more regions of the world, an adequate supply of this precious resource is becoming increasingly challenging.
- The MED (Multi-Effect Desalination) process is characterized by very low energy consumption compared with other thermal processes.
- It is highly reliable and simple to operate.
- It can be operated continuously for up to 24-hour-a-day with minimum operations and maintenance activities or supervision.
- MED can be designed for small scale water production with the capacity smaller than 50 m3/day.
- MED was modified economically and thermally for small and medium scales water production for the first time.
- MED can be operated for large scale water production up to 2000 m3/day.
- MED operates at low temperatures and at low concentrations to avoid corrosion and scaling.
- MED can be operated for both brackish water and seawater.
- Arta Co. has combined the MED system with PTC solar collectors. The thermal energy required for MED is supplied by the solar system. The capability of providing ‘’Thermal Energy Storage’’ leads to high capacity factors that are of prime importance for major industrial consumers.
- The PTC (parabolic trough collector) is tuned with a low price for combination with desalination systems especially HDH and MED systems.
- Being modular and easy maintenance are the main advantages of the present design.
- The control systems provided for the hybrid system are the main innovation of Arta Co. which minimizes energy consumption.
- In the combined solar collector and MED, the required thermal energy is supplied by the solar system.
Review of Arta MED Desalination Technology
Arta MED-PTC, while running directly on solar energy offers simultaneously different qualities of water; drinking, irrigation, demineralize water.
- Simplifying a technology especially for small and medium scales.
- Carefully designed for low-income communities with all their needs.
- The Arta. MED desalination system can use any waste energy to start up.
- Arta systems are modern, and at the same time simple, solutions for any of off-grid communities struggling with their supply of water.
Specifications of Arta. Co MED technology
|Vacuum System||Included by ejectors|
|Dist. Pump||S.S. 304/316/super duplex|
|Brine Pump||S.S. 304/316/super duplex|
|Heat exchanger/Condenser||S.S. 304/316/super duplex/ Aluminum brass/ Ti.|
|Cover/body||Corrosion-resistant by a special coating|
|Water temp.||Max. 35-40 C|
|Residual salt content||< 10 ppm|
Operational parameters of Arta. Co MED technology
|Electricity Consumption of MED||1-1.5 kWh/m^3|
|Operation & Maintenance per Year||1/year|
|Pre-Treatment of Water||Simple|
B. Zero Liquid Discharge (ZLD) Technology
- ZLD is a water treatment process in which all wastewater is purified and recycled; therefore, leaving zero discharge at the end of the treatment cycle.
- Zero liquid discharge is an advanced wastewater treatment method that is included evaporation and crystallization.
In the ZLD system, different technologies are combined. Initially, the saline water is entering the evaporator. Then, it is entering the crystallizer, and the solid particles are immersed in the solution as crystals. The effluent is entering the centrifuge from the crystallizer. Consequently, the dry salt is produced with very low humidity.
- The ZLD was coupled with a MED system. The brine of the MED was transported to ZLD for water production.
- ZLD is a very expensive technology in the word! Arta Co. is developing an efficient technology for small and medium scales (< 50 m3/day production). In this scale, it is possible to reuse the brine of the different systems, economically. In other words, the brine of reverse osmosis (RO) systems can be employed for extra freshwater production.
- Both ‘falling film evaporation’ and ‘Mechanical Vapor Compression’ (MVC) are used in the ZLD technology.
- Higher recovery
- Minimal Oﬄine Cleaning
C. Arta Humidification-dehumidification (HDH) Technology
Humidification dehumidification (HDH) is a thermal desalination technology. Its basic components are a humidifier, a dehumidifier, and a heater. In the humidifier, the air is humidified through direct contact with salty water. In the dehumidifier, hot moist air is put in indirect contact with cold salty water. This causes water vapor to be condensed, which is producing a freshwater stream.
- Simple and low-cost construction;
- Low maintenance requirements;
- Combination with solar collectors with high efficiency;
Innovations in Arta HDH:
- Multi-stage air heated HDH
- Mechanical compression HDH
- HDH with a common heat transfer wall
- New embodiments of HDH are under development. It can potentially improve upon the simple HDH technology.
- Further research is under progress at Arta Co. to make HDH a low-cost desalination system.
- Using HDH in ‘seawater greenhouse’ for the first time.