Gas inFusion Technology
Gas inFusion Technology is a global platform technology with numerous potential market uses, both stand alone and bundled with other technologies. The Technology is a unique method of infusing gas into liquids with demonstrated ability to: Effect rapid, no bubble, gas transfer (inFusion); Create ultra-saturation dissolved gas conditions, e.g., dissolved oxygen concentrations of hundreds of PPM; Allow long term retention of very high, dissolved gas concentrations; Eliminate most dissolved gas losses into the atmosphere; Achieve gas transfer efficiencies with respect to power used, of 7 to 9 times that of the best conventional methods; Produce less dense liquids; Enhance performance and increase capacity of existing process infrastructures; Be flexible and comparatively small to be fitted into, or parallel to, conventional process technologies; and Be easily operated and maintained.
Gas inFusion is a mass transfer operation whereby sparingly soluble gases are dissolved in liquids in a completely bubbleless fashion. The efficiency of this manner of mass transfer allows the production of stable liquid streams containing enormous quantities of dissolved gas on scales ranging from cc/min to thousands of GPM at a fraction of the energy cost normally associated with gas dissolution.
The dissolution of sparingly soluble gases into liquids is normally considered to be an energy intensive process. A prime example of this would be in wastewater treatment where huge energy consuming air blowers and bubble diffusers are used to dissolve oxygen in water for the purposes of bio-degradation.
The amount of gas that a liquid can hold in solution is generally governed for sparingly soluble gases by Henry's Law. In itself, Henry's Law is an equilibrium statement. Typically, dissolving or solubilizing a sparingly soluble gas is a very slow process. Solubilization is a mass transfer operation. Mass transfer operations require two things in order to occur:a driving force and a means.
Driving force: in order for net oxygen transfer (O2 being an example) from the gas phase to the liquid phase to occur, equilibrium must not exist. In other words, the measured value of dissolved oxygen in the water must be less than the equilibrium value. This difference between the values is the reason that mass transfer occurs. As well, the greater the difference the faster the mass transfer will take place
Means: the means is simply a path for the gas to follow, which connects the two phases and an interface must exist. The greater the interfacial surface area between the two phases the more rapid the mass transfer.
The device or apparatus of choice, which provides the maximum amount of surface area, is a hollow fibre membrane module. The hollow fibres should be hydrophobic, and ideally have a large porosity. Such a device should have:
- An exceptionally large surface area: volume ratio
- The ability to operate at very high pressures
- A high tolerance to a pure gas environment
- Inherently good flow distribution
At first glance, operating under pressure would seem to be very energy consuming. However, the end use must be borne in mind. If for example, the need is for a water stream containing 4 ppm of dissolved oxygen, and the infusion conditions are such that 200 ppm of dissolved oxygen are produced, then only 2% of the actual liquid stream need be infused!
InVentures manufactures Gas inFusion devices. In cooperation with the National Research Council of Canada, we modeled and correlated the performance of such devices, for oxygen, as shown below. Infusion of other gases into other liquids correlates in a similar manner.
Transferring of the gas to the liquid is actually only the first part of an entire Gas inFusion process. For oxygen especially, the downstream uses would typically occur at atmospheric pressure. Wastewater treatment would be a prime example of a process that could benefit from increased dissolved oxygen levels. The infusion portion of the process must necessarily be followed by a pressure reduction of the (high gas content) liquid in order for the gas (oxygen) to be utilized. Once reduced in pressure, the liquid, by definition, would be supersaturated.
As the pressure is relieved, the liquid moves through the stages of being less than saturated, to saturated, and finally to being supersaturated. If this pressure reduction is not performed correctly, the gas will immediately come out of solution in the form of copious quantities of large bubbles. In short, much of the energy expended putting the gas into solution would have been wasted. When the pressure is reduced properly the oxygen (gas), when it does come out of solution, does so in the form of extremely fine bubbles. Typically, the size of the bubbles is on the order of 50 microns or less. This is more than an order of magnitude smaller than the smallest bubbles produced using the finest bubble diffusers. Therefore, these bubbles rise much slower and again, are much more readily available for the biological or chemical processes they were intended for.
When a gas-saturated liquid is introduced into a vessel using Gas inFusion, the saturated condition remains for many days, waiting to be used by process demand be it biological or chemical.
The supersaturation half-life correlates well with the depth of the vessel, as illustrated in the figure to the right. It correlates even better when other dimensional parameters of the vessel are taken into account. Half-lives in excess of a week are obtainable in 10 ft. deep open-top vessels. The unique nature of the Gas inFusion technology allows it to be easily fit into an existing process to enhance performance and to increase capacity, or to design a 'grass roots' system around this unique technology.
inVentures is currently focused on several market applications, including:
- Groundwater Remediation
- Food and Beverage
- Process Innovation
- Water Treatment