Systems and methods for recycling gas in reactors

A fermentation reactor comprising:

• an enclosure including a loop section, enclosing an internal space comprising a gas space and a liquid space, wherein the liquid space includes liquid, and wherein the gas space is configured to collect gas separated from the liquid space within a reactor;
• a liquid pump arranged in the liquid space to increase or maintain pressure and flow direction in the liquid space and prevent or reduce backflow of gas bubbles in the liquid space;
• and
• a powered propeller comprising:
• a shaft having an upper end and a lower end, wherein the lower end extends into the liquid space;
• a plurality of blades connected to the lower end of the shaft;
• and
• a gas conduit extending from a first end to a second end, wherein the first end is in gas communication with the gas space, and wherein the second end is proximate the blades and extending into the liquid space;
• wherein upon rotation of the powered propeller, the powered propeller is configured to:
• generate a suction to cause the collected gas to flow from the gas space to the liquid space through the gas conduit;
• and
• mix the liquid and the collected gas proximate the powered propeller.

A loop-shaped reactor comprising:

• an enclosure including a loop section, enclosing an internal space comprising a gas space and a liquid space, wherein the liquid space includes liquid, and wherein the gas space is configured to collect gas separated from the liquid space within a reactor;
• a liquid pump arranged in the liquid space to increase or maintain pressure and flow direction in the liquid space and prevent or reduce backflow of gas bubbles in the liquid space;
• and
• a powered propeller comprising:
• a shaft having an upper end and a lower end, wherein the lower end extends into the liquid space;
• a plurality of blades connected to the lower end of the shaft;
• and
• a gas conduit extending from a first end to a second end, wherein the first end is in gas communication with the gas space, and wherein the second end is proximate the blades and extending into the liquid space;
• wherein upon rotation of the powered propeller, the powered propeller is configured to:
• generate a suction to cause the collected gas to flow from the gas space to the liquid space through the gas conduit;
• and
• mix the liquid and the collected gas proximate the powered propeller,
• wherein the loop reactor causes fluid therein to flow from the lower portion of the liquid space to the upper portion of the liquid space through the loop section.

A process for recycling gas in a loop-shaped reactor, the process comprising:

• collecting gas separated from a liquid space in a gas space within an enclosure of a gas-recycling system, the gas recycling system comprising:
• an enclosure including a loop section, enclosing an internal space comprising a gas space and a liquid space, wherein the liquid space includes liquid, and wherein the gas space is configured to collect gas separated from the liquid space within a reactor;
• a liquid pump arranged in the liquid space to increase or maintain pressure and flow direction in the liquid space and prevent or reduce backflow of gas bubbles in the liquid space;
• and
• a powered propeller comprising:
• a shaft having an upper end and a lower end, wherein the lower end extends into the liquid space;
• a plurality of blades connected to the lower end of the shaft;
• and
• a gas conduit extending from a first end to a second end, wherein the first end is in gas communication with the gas space, and wherein the second end is proximate the blades and extending into the liquid space;
• rotating the powered propeller to:
• generate a suction to cause the collected gas to flow from the gas space to the liquid space through the gas conduit;
• and
• mix the liquid and the collected gas proximate the powered propeller.

A process for producing biomass, the process comprising:

• culturing a microorganism in a reaction mixture in a reactor, wherein the reaction mixture comprises a liquid medium, wherein the microorganism is capable of converting CO2 into biomass;
• introducing a substrate from an external source into the liquid medium and mixing the substrate with the liquid medium, wherein the substrate comprises CO2, H2, or O2;
• recycling gas separated from a liquid space back into the liquid space within the reactor, the reactor comprising:
• an enclosure including a loop section, enclosing an internal space comprising a gas space and a liquid space, wherein the liquid space includes liquid, and wherein the gas space is configured to collect gas separated from the liquid space within a reactor;
• a liquid pump arranged in the liquid space to increase or maintain pressure and flow direction in the liquid space and prevent or reduce backflow of gas bubbles in the liquid space;
• and
• a powered propeller comprising:
• a shaft having an upper end and a lower end, wherein the lower end extends into the liquid space;
• a plurality of blades connected to the lower end of the shaft;
• and
• a gas conduit extending from a first end to a second end, wherein the first end is in gas communication with the gas space, and wherein the second end is proximate the blades and extending into the liquid space;
• collecting gas separated from the liquid space in the gas space;
• rotating the powered propeller to:
• generate a Venturi suction to cause the collected gas to flow from the gas space to the liquid space through the gas conduit;
• and
• mix the liquid and the collected gas proximate the powered propeller;
• and
• harvesting the biomass produced from the reactor.