what we do

Circular H₂O is commercializing a patent-protected, membrane-free, energy-efficient Zero Liquid Discharge (ZLD) and Mineral Extraction System. This technology has the ability to integrate into a multiple-step solution within existing systems (e.g., reverse osmosis [RO] plants), allowing it to operate on top of any existing water desalination facility.

The Problem

The world is heavily reliant on minerals like sodium, magnesium, calcium, bromine, lithium, and potassium.
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Many of these industries, such as magnesium and bromine, are struggling to keep up with current demand. These minerals can be found in large amounts in different brines, like sea water, geothermal brine, and oil and gas co-produce.

Current desalination technologies require large amounts of energy and extremely high temperatures, and they can't selectively target multiple minerals. While some processes do exist for extracting specific minerals like lithium or bromine, they can be very complex and costly.

Potable Water Needs are Ever-Increasing

Many places in the world don’t have access to enough naturally potable water and require desalinated water. In the MENA region, for example, water consumption is higher than average, but access to potable running water is scarce in many countries.

In the U.S., many regions are already experiencing water shortages, and the population is expected to increase 30% in the next 20 years, which will only exacerbate the problem. However, many forms of water desalination are energy intensive. Without intervention, desalination will increase fossil fuel dependence and CO₂ emissions.

The solution

Zero Liquid Discharge (ZLD) and Mineral Extraction System

Circular H2O’s Zero Liquid Discharge (ZLD) and Mineral Extraction System has made mineral extraction from seawater and other brines more cost competitive and energy efficient than traditional mining or desalination processes. Coupled with the right technologies, this solution is intended to form a full downstream brine processing sequence.

The ZLD and Mineral Extraction System combines two different functions: switchable solvent water extraction (SSWE) and switchable solvent fractional precipitation (SSFP). These paired technologies process brine or other aqueous solutions through treatment with a specially selected miscible organic solvent/gas. The gas operates with low pressure and temperature gradients to optimize energy consumption, increase efficiency, and extract high purity minerals.

Key features

Membrane-free

Eliminates the evaporating ponds & crystallizers

Up to 99.5% recyclability
of the selected organic gas

Runs on renewable
energy

Financially scalable

What we can extract

Depending on the initial level of concentration of the minerals in the treated brine, the technology will enable multiple mineral extractions sequentially, which may include:

Ca++

Na+

Mg2+

SO₄

K+

Cl-

More elements

Ammonium

NH₄₊

Iron

FE++

Boron

B+++

Arsenic

AS

Copper

CU

Molybdenum

MO

Silica

SIO₂

Nitrate

NO₃

Nitrite

N

Switchable Solvent Fractional Precipitation

In a SSFP system, hard water or high concentration brine mixes in the system as a gas or liquid, driving the fractional precipitation of solutes from the saline brine solution. Solid precipitates are separated before the mixture is decomposed or heated to drive the vaporization of the gas. The gas then undergoes compression and liquefaction to be recycled.

The solids are extracted, and the aqueous solution is passed to the next stage of the treatment process (additional stages as needed). A pressure exchanger can be used to recover energy from the expansion process.

How it Works

In the first stage of the SSWE system, the liquid selected organic gas comes into contact with the brine or aqueous fluid to be treated at a selected controlled pressure and temperature point, which induces the precipitation of salts.

The salts settle at the bottom of the container and are removed as a slurry. The slurry can be fed into a selective precipitation system where specific byproducts can be extracted.

In the sequential stages, as the selected organic gas encounters the salt slurry, it induces the precipitation of salt(s) near saturation. The solid salts may be separated via gravity methods, hydrocyclone, or ultrafiltration.

The temperature and pressure are then adjusted, allowing the selected organic gas to become gas (and separate from the water) and be compressed back to gas to be reused in a closed-loop cycle.