HRS to supply mechanical vapor recompression for EU-funded ZLD project
HRS Heat Exchangers, part of UK-headed heat transfer technology solutions providers HRS Group has announced that it has been awarded an order for the design, manufacture, and installation of a Mechanical Vapor Recompression (MVR) Evaporation System for the LIFE Desirows consortium, which is demonstrating a circular economy zero liquid discharge (ZLD) project to improve water quality in Murcia region, Spain.
LIFE Desirows is an EU research project which is studying a way of extracting useful salts and products from the brines which are generated by reverse osmosis (RO) technology which is used to create irrigation water.
If not treated properly, these brines can contribute to the level of nitrates being discharged into watercourses in the region which then causes a deterioration in water quality.
This deterioration of water quality has had a negative effect on the tourism industry, which together with agriculture is the main economic driver in the region of Murcia.
To find an urgent solution to the issue, a consortium of companies has teamed up with the Polytechnic University of Cartagena (UPCT) to investigate a treatment solution for the agricultural brines which present an environmental challenge in the Mar Menor and Mediterranean areas around Murcia.
Develop industrial circular economy process
The consortium has developed a circular economy process that removes nutrients and separates different salts from the brine so that they can be used as fertilizers while maximizing the reuse of water for irrigation from both urban and groundwater purification.
Firstly, a double RO process generates a second brine which then goes through denitrification and chemical precipitation process which removes the nutrients and the salts. The resulting solution is then thermally concentrated using a cooling tower and mechanical vapor compression (MVC) to produce a saturated solution.
Finally, the precipitated salts are removed from this saturated solution using Wind-Aided Intensified Evaporation, providing a true zero liquid discharge (ZLD) solution that converts the environmentally unfriendly brine into clean water for irrigation, fertilizer, and salts for industrial use.
The technology has potential applications in a range of situations, but in the LIFE Desirows project, it prevents the leakage of unwanted substances from agriculture into watercourses.
The processes are powered by renewable electrical sources, including solar PV and biomass power.
HRS MVR evaporation solution
HRS is providing the consortium with a forced recirculation evaporator driven by mechanical vapor recompression (MVR). According to HRS, MVR evaporation is one of the most economical ways of concentrating waste streams and does not require a thermal energy source. The electrical energy needed to drive the MVR compressor is supplied by photovoltaic solar panels.
The evaporation module uses HRS corrugated tube technology which is ideal for the concentration of brine. The corrugated tubes generate extra product turbulence, which provides enhanced heat transfer and also delays heat exchanger fouling.
Both of which are crucial features when dealing with challenging products such as brines and wastewaters.
HRS is delighted to contribute with a technical solution for this environmental challenge. With both our office and manufacturing facility being in the Murcia region. As a company with local facilities, we are aware of the environmental problems suffered in the Mar Menor and are delighted to be able to try to help solve them. Product trials were conducted with the Polytechnic University of Cartagena to investigate the evaporation process and ensure the right choice of technology. HRS has delivered several zero liquid discharge systems to customers in Spain, giving us the confidence to solve the concentration part of the LIFE Desirows system with our corrugated tube MVR evaporator, said Tomas Stiebe, one of HRS’s evaporation experts.