A process for fermenting syngas is provided which is effective for decreasing an amount of time needed to inoculate a main reactor. The process includes propagating a culture of acetogenic bacteria to provide an inoculum for a main reactor and fermenting syngas in the main reactor.

A method for processing a fluid includes removably securing a retention member to a vessel that bounds a chamber; inserting a collapsible bag within the chamber of the vessel; securing the bag to the retention member so that the bag is supported within the chamber of the vessel; and dispensing a fluid into a compartment of the collapsible bag supported within the chamber of the vessel. The fluid can be mixed within bag while the bag is disposed within the vessel.

Aspects of the invention describe a tube diffuser design and associated saddle design that allow the two elements to be easily and quickly attached to each other in the field for the purpose of aerating wastewater. The tube diffuser is cylindrical and includes a gas distribution section spanning across an interior diameter of the tube diffuser. The saddle includes a pair of engagement arms that are able to couple to this gas distribution section of the tube diffuser. Once the tube diffuser is attached to the saddle and the assembly is submerged in wastewater, the saddle may be used to transport air from an air distribution pipe to the tube diffuser. The air may then be made to leave the tube diffuser as a plume of air bubbles.

The present disclosure relates to an apparatus for generating nanobubbles of a gas in a liquid, the apparatus including: (a) an outer tube; (b) a porous inner tube coaxially located within the outer tube that is at least partially occluded so as to define one or more liquid flow paths through the inner tube; (c) a pair of end assemblies attached to respective first and second ends of the outer tube, each end assembly having an opening in fluid communication with the one or more liquid flow paths so as to allow a flow of liquid in an axial direction through the apparatus; and, (d) a gas inlet for allowing a flow of gas into a chamber formed between the outer and inner tube, the flow of gas permitted to permeate through the porous inner tube into the one or more liquid flow paths, wherein, as the gas permeates through the porous inner tube, nanobubbles of gas are generated which become entrained in the liquid flow.

The systems and methods disclosed herein provide for the efficient generation of fine bubbles. In particular, systems and methods for use in bioreactors are disclosed herein providing a superior means to produce useful fermentation products by the biological fermentation of fine bubble waste substrates injected into a liquid broth containing a microorganism culture.

A hollow expansion chamber of the present invention is configured to temporarily contain an expansion of bubbles during an aeration process for aerating a liquid, where a chamber body of the expansion chamber has a rounded shape. When moving circumferentially downward along the chamber body starting from a maximum inside diameter, the rounded shape of a bottom portion has a first integral transition that is a tangential transition to a first frustoconical shape. Continuing moving circumferentially downward, the first frustoconical shape has a second integral transition to a cylindrical extension. The cylindrical extension at a distal end has a bottom opening configured to fit within an opened bottleneck. The first frustoconical shape has a minimum angle of 15 degrees relative to a horizontal plane. The second integral transition is a radial second integral transition having an inside surface radius of at least 0.25 inches.

A nano-bubble-generating apparatus includes: an elongate housing defining an interior cavity adapted for receiving a liquid carrier, a liquid inlet, and a liquid outlet; a gas-permeable member at least partially disposed within the interior cavity of the housing that includes a first end adapted for receiving a pressurized gas, a second end, and a porous sidewall; and an electrical conductor adapted to generate a magnetic flux parallel to an outer surface of the gas-permeable member as the liquid carrier flows from the liquid inlet to the liquid outlet. The housing and gas-permeable member are configured such that the flow rate of the liquid carrier flowing parallel to the outer surface of the gas-permeable member is greater than the turbulent threshold of the liquid to create turbulent flow conditions, thereby allowing the liquid to shear gas from the outer surface of the gas-permeable member and form nano-bubbles in the liquid carrier.

A passive gas exchange transfer apparatus for exchanging carbon dioxide from a flue gas to a water supply is disclosed. The apparatus includes several upper rods and several lower rods to hold a membrane in place. The membrane provides increased surface area for the gas and the water to meet. The upper rods may be the source of the water supply, and the lower rods may be the source of the gas. The upper rods may disperse the water onto one side of the membrane, and the lower rods may disperse the gas onto the other side. The two may therefore meet at the surface created by the membrane as gravity draws the water downward, and convection draws the gas upward.

A device for generating gas bubbles in a liquid in a container includes a rotatable gas-permeable hollow shaft arranged in a container, gassing discs arranged on the hollow shaft and spacers arranged between the gassing discs, gassing discs and spacers being arranged alternately on the hollow shaft in gas-tight contact with one another, a feed line for a compressed gas into the interior of the shaft, spacer having a centered opening (O) for receiving the shaft and at least two chambers, the chambers being equally spaced around the centered opening, where the centered opening and the chambers at least partially overlap, where the centered opening and the chambers are in communication with one another at least in the overlap region, so that the compressed gas can flow from the shaft into in each case a chamber of the spacer and enter the gassing discs from the chamber of the spacer.

An aeration apparatus including a tank defining a cavity to receive a liquid, at least one aerator positioned within the tank, and a plenum connected to a bottom surface of the tank and in fluid communication with the at least one aerator, in which an air flow is directed from the plenum into the at least one aerator to deliver air to the liquid in the tank to oxidize the fluid.