Technology Outline (Process Description)

The solar-biomass MED-TVC desalination system is one of the competitive solutions to the existing water scarcity issue both technologically and economically. Performance of Solar/Biomass based MED-TVC seawater Desalination System at Narippaiyur, a coastal village in the district of Ramanathapuram, Tamil Nadu has been carried by primarily improving the Gain output ratio. In order to achieve this TVC design has been modified for 10 bar motive steam without affecting the mechanical capability of the existing system. After the installation of new TVC nozzle GOR from the original value of 7 to is 11.5. This leads to greater reduction of specific thermal energy consumption. In addition to this conical seawater spray pattern on the tube has replaced with square pattern to reduce the stray effects associated with overlap. This system produces 6 m³/day of desalinated water having TDS less than 5 ppm. Brine reject from the plant was effectively utilised for growing Algae in a photo bioreactor.

Based on the observed seawater corrosion of Al 6061 tubes in the evaporator tube bundle, relatively less susceptible Al 5052 tubes were used to replace Al 6061 tubes in order to improve durability. Direct steam generating LFR solar collector having Evacuated tube receiver with secondary concentrator having low cost of steam generation than the existing LFR with multi tube receiver was demonstrated.

Scientific data acquisition, analysis and performance evaluation of the plant are performed to develop an in-depth understanding of scientific and technological aspects of running Solar Biomass Thermal Desalination plant in coastline Indian conditions in the arid climatic zone. This technology is being developed and demonstrated as a reliable, cost effective and scalable solution to address prevalent and emerging water challenges in mission mode.