Vertical Tube Extraction (Desalination) Pilot Project

Vertical Tube Extraction (Desalination) Pilot Project

The Salton Sea is excessively saline, affecting the ability of the Sea to sustain its biological resources. The Salton Sea Authority would conduct a 7-month pilot project to demonstrate the feasibility of reducing the salinity of the Sea water by using geothermal steam, rejected from power turbines at the Cal Energy plant, to drive the desalination process using vertical tube evaporation. The evaporator facility is a brine concentrator prototype designed, constructed, and tested on seawater for 1 year at the University of California and for 18 years in Modesto, California. In 2002, the evaporator facility was dismantled and moved to the U.S. Bureau of Reclamation's Salton Sea Navy Test Site, where it would be cleaned and repainted for this project. The equipment would be assembled on a 35-foot by 35-foot reinforced concrete pad at the CalEnergy Geothermal Plant, located at 6920 Lack Road, Calipatria, California. The heat energy from the steam is re-used about 15 times to generate 15-fold its weight in distilled water. Gypsum and brine are the other two products of this process. The distilled water would be mixed with untreated Salton Sea water and/or brine and discharged back into the Sea. The gypsum would be trucked to an authorized disposal facility. Brine would also be injected with the residual brine from CalEnergy's geothermal process back into the geothermal field using existing injection wells. Sodium sulfate would be removed from the brine to qualify the brine for injection by CalEnergy into the geothermal field. It is expected that the product would be sold to industry. The main objectives of this pilot project are to demonstrate the feasibility of the proposed multi-effect desalination process and to obtain needed test data with the pilot plant.

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