Background

Zero Energy Water has harnessed the inherent properties of graphene to create a patented industry-compatible membrane that significantly improves flux and reduces energy consumption in water purification and desalination.

• Industry Compatible - Zero Energy Water membranes will be used to create industry standard filter modules to allow plug and play upgrades to both new and existing reverse-osmosis applications.

• Cost Comparable - Zero Energy Water membranes will cost approximately the same amount to produce as existing membranes.

• Longer Lasting - Zero Energy Water membranes are projected to last longer than membranes currently offered in the market place.

Hydro-Pico-Filtration 

A Molecular Sieve Technology Selective for H2O Molecules

Zero Energy Water’s new porous membrane represents a new class of filtration that we are calling Hydro-Pico-Filtration (HPF). Hydro-Pico-Filtration provides an alternative solution to reverse osmosis applications, specifically allowing for a lower energy solution for the separation of compounds and ions from water, the result being ultra-pure water or water with enhanced ionic concentrations.  Compared to ultrafiltration, nanofiltration, and semi-permeable separations (RO), Hydro-Pico-Filtration flow rates are dictated by the spacing between the graphene plates in combination with electrical charges and Van der Waal’s forces.  The result is that Hydro-Pico-Filtration rejects almost everything except water molecules, filtering total dissolved solids at almost the same rejection rate as semi-permeable membranes but with the much lower energy profile referenced previously.

What Pressures are Required?

Zero Energy Water’s Hydro-Pico-Filtration (HPF) technology works similarly to cross-flow, reverse-osmosis filtration.  After accounting for osmotic pressure, activation pressure for HPF is about 60 PSI (P0) with flux overtaking semi-permeable desalinization membranes at an over pressure 400 PSI (total pressure minus osmotic pressure). Flux across the hydro-pico-filter is approximated by classic filtration relationships, such as Q=k(P-Po)x where x is approximately 0.5. The result being a continued increase in flux as pressure increases.  A flux of up to 270 GFD at 800 psi in a sea water desalination test has been documented by an external lab.

Performance Characteristics

As previously stated, Hydro-Pico-Filtration membranes offer higher flux when compared to polyamide-based Reverse Osmosis membranes under the same conditions. The diffusion pressure curve is also different from the filtration pressure curve with a cross over at approximately 400 PSI where the flux of the Hydro-Pico-Filtration membrane surpasses the flux of the Reverse Osmosis membrane and continues to increase as the pressure differential increases.

Properties of Zero Energy Water’s Hydro-Pico-Filter membrane:

• - High rejection (+96.5-99%) of all ions: valences of 1, 2,3,4,5 and 6
• - Higher flux that continues to increase with pressure - in excess of 250 GFD at 800 psi.
• - The graphene composite is non-reactive to chlorine.  This may not be true of the substrate.
• - The graphene composite is non-reactive to organic solvents. This may not be true of the substrate.

Hydro-Pico-Filtration applications

Hydro-Pico-Filtration is limited to the treatment of water - either water suspensions or organic suspensions containing water. The key benefit of a Hydro-Pico-Filter is the rejection of all but water molecules. This includes uses impacted by boron, chlorine, fluorine or organic solvents. Hydro-Pico-Filtration is based on graphene composite materials. These materials maintain stability when exposed to organic solvents making Hydro-Pico-Filtration ideal for industries currently not suitable for polyamide based Reverse Osmosis systems.  For example, Hydro-Pico-Filtration can be used in various applications such as:

• - Drinking water, desalination of sea and brackish water, household usage
• - Separation of ions in hydrometallurgy
• - Separation of emulsified organics in oil and gas
• - Medical, including drug manufacturing and laboratory usages
• - Production of dairy products
• - In desalination, Hydro-Pico-Filtration is used to remove the bulk of the total dissolved solids (TDS) as part of a 2-pass process.
• - In sea water desalination an additional stage either before Hydro-Pico-Filtration using Nanofiltration or a second pass of Hydro-Pico-Filtration will result in 99.9% removal of dissolved solids while maintaining a higher overall flux per unit of energy used.
• - In brackish water desalination, at higher pressures Hydro-Pico-Filtration can replace the batch processes currently in use and provide high quality of water at a lower cost of energy per gallon of permeate produced.

There are other applications in the water purification industry where the cost to remove TDS at high concentration using an RO system is energy intensive.  Significant energy savings can be achieved by Hydro-Pico-Filtration systems as the flux at higher pressures can be as much as ten times higher than a traditional polyamide based semi-permeable membrane.  Chemical industries (including petrochemicals and pharmaceuticals) have many different applications suitable for the Hydro-Pico-Filtration technology due to its selective removal of water and tolerance to a wide range of pH and organics concentrations.  

Classification of separation membranes, according to their pore openings

Microfiltration:

• - Molecular Weight Cut Off (MWCO) > 100 kDa 
• - Pore Size 0.1-10um 
• - Species Rejected - Suspended Solids, Bacteria, Colloids and Fats
• - Applications: Pre-treatment, Microbial Separations

Ultrafiltration:

• - MWCO: 10-100 kDa
• - Pore Size: 10-100nm
• - Species Rejected: Viruses, Polypeptides, Proteins
• - Applications: Pre-treatment of Drinking Water, Proteins

Nanofiltration:

• - MWCO: 0.2-10 kDa
• - Pore Size: 1-10nm
• - Species Rejected: Multivalent Ions, Organic Solvents, Sugars
• - Applications: Drinking Water, Sugar Separation, Lactose

Reverse Osmosis:

• - MWCO: <200 Da
• - Pore Size: < 1 nm
• - Species Rejected: Salts, PFAS, Monovalent Ions
• - Applications: Desalination, Ionic Separations

Hydro-Pico-Filtration:

• - MWCO: <18 Da
• - Pore Size: < 1 nm
• - Species Rejected: Selective for Water
• - Applications: Water Removal or Purification

Difference between Hydro-Pico-Filtration and Reverse Osmosis using semi-permeable membranes 

Although Hydro-Pico-Filtration and Reverse Osmosis systems share the same design and operational applications, there are some significant differences:

1. Different pressure response (Up to 10 times Higher Flux): Hydro-Pico-Filtration has a different pressure curve than semi-permeable membranes. Hydro-Pico-Filtration operates at moderate water pressure with fluxes surpassing semi-permeable membranes at an over pressure (total pressure minus osmotic pressure) of approximately 400 PSI.
2. Rejection: While semi-permeable membrane systems can remove up to 99.7% of chloride and sodium, the current generation of Hydro-Pico-Filtration membranes typically remove only 98.5-99%. This percentage depends on the type of material and the film manufacturing process. However, due to its effectiveness in removing both monocharged and multi-charged ions, and its higher flux, Hydro-Pico-Filtration is the preferred option for expensive seawater desalination applications.
3. Ion species: Hydro-Pico-Filtration is regulated by the characteristics of graphene: spacing (pore size), electrical charge and Van der Wall’s forces.  This makes these membranes suitable to the rejection of many dissolves species not affectively filtered by semi-permeable membranes
4. Organic material stability: with the selection of the appropriate substrate, Hydro-Pico-Filtration membranes are stable in many organic solvent environments.

Applications

Saltwater and Brackish Water Desalinization

Industrial Reverse Osmosis

Oil/Water Separation

 Water Treatment

Industries

Mining

Municipal

Desalinization

Food Preparation

Availability

Shipping in small quantities for evaluation purposes.