Sonoran CryoDesal LLC Freeze Desalination: non-membrane desalination technology for difficult water / wastewater streams.

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1 Sonoran CryoDesal LLC Freeze Desalination: non-membrane desalination technology for difficult water / wastewater streams July 17,

2 CryoDesalination: When RO Is Not a Good Option Reverse Osmosis (RO) is a popular desalination technology that uses membranes for moderate salt concentration, up to seawater (about 3.5% or 35,000 ppm). RO requires pretreatment and/or filtering of solid particles, minerals that can foul, organics, and oxidants. RO is not effective with high salt concentrations, wastewater etc. Fresh water can be frozen out any quality of brine/waste water, including industrial and waste water streams which can have very high salt levels even up to saturation (about 26% or 260,000 ppm) Industrial waste streams, effluents Wellfield produced water Seawater, saline groundwater It can even desalinate the concentrated output from RO systems RO systems typically reject 5 times as much water as is cleaned CryoDesal is scalable from small to very large capacities. Low temperature, low pressure process Works with any type of salt, any level of concentration ZLD (zero liquid discharge) possible by dropping out salts as solids Cost and efficiency improves with size very large plants are possible 2

3 CryoDesalination Freeze desalination is not new - nature does it on a global scale. Ice formed from saltwater or brine water is inherently purified. The salt is left behind in the surrounding water Many attempts at freeze separation were supported by US Bureau of Reclamation and others. Efficiently separating clean ice from the remaining concentrate was a major issue CryoDesal overcomes the ice/brine separation problem with a patented process: Ice remains a slurry at all times, as it is pumped and separated. Avoids the handling of solids No membranes which can foul, requiring replacement Feed pre-treatment is minimal, such as removal of large quantities of oil and solids. Low temperature permits use of low cost materials of construction. Energy efficient with potentially low capital costs No chemicals are needed for scale or corrosion inhibition 3

4 CryoDesal Process Saline or wastewater is frozen by direct contact of liquid propane acting as refrigerant mixed and bubbled up within the incoming brine. Small crystals of ice are formed, and create a flow of ice slurry in brine. Direct freezing is thermally efficient, and simplifies equipment Separation of purified ice from brine is by flotation. Water-immiscible oil having a specific gravity between ice and water with proper viscosity and surface tension performs the separation. Ice is separated, washed of brine and remelted for energy recovery No high pressure or membrane replacements are required ZLD (zero liquid discharge) can be achieved if desired, by operating at the eutectic temperature making crystalline salt (solids) in the process. Solids can be easily transported and disposed of, or considered for its metal or mineral value 4

5 Energy Required Energy required per water unit is higher than RO, but much less than thermal-distillation Energy required is primarily for propane recompression. The amount of propane consumption is related to the salinity of the reject stream which determines the freezing temperature For the harshest streams, a large scale efficient plant would require under 20 kwh per cubic meter to provide clean water and reject waste concentrate near saturation, or even to solids (ZLD) Process can be driven by Solar, including direct drive of compression by solar-driven turbines 5

6 Status Separation process has been demonstrated with a small pilot plant, designed for 8 to 10 GPM. This demonstration used bottled propane and did not include propane recovery, which would be done in operational systems using standard propane compression methods Next step is to develop a lab R&D/demonstration plant, including propane recovery, leading to a field application such as recovery of produced water from Oil & Gas in the US southwest 6

7 Capital Cost Projections Initial development and product units can be small to use low cost commercial refrigeration/compressor units gpd Large scale plants would use large industrial centrifugal compressors 1000 s to even millions of GPD (gallons per day) 7

8 Solar Plant with CryoDesal Facility Solar can be used for electricity to drive the process, or by solar thermal turbines directly driving compressors for higher efficiency 8

9 Potential Markets Separate salts from water, any level of concentration from: Industrial waste streams, effluents Oil wellfield produced drilling water Recovery and reduction of concentrated output from RO systems (typically 5 times as much water as is cleaned) Municipal desalination from seawater, saline groundwater ZLD (zero liquid discharge) possible by dropping out salts as solids Very large scale plants possible millions of GPD 9