FERMENTATION CONTROL FOR OPTIMIZATION OF SYNGAS UTILIZATION

• US 20170356012A1
• Filed: 11/13/2015
• Published: 12/14/2017
• Est. Priority Date: 11/13/2014
• Status: Active Grant

• Current Assignee: Board of Regents of Oklahoma State University
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Atiyeh, Hasan K., Phillips, John Randall, Huhnke, Raymond L.
• Granted Patent: US 10,640,792 B2
• Time in Patent Office: Days
• CPC Class Codes: C12P 7/065 with microorganisms other than yeasts
• CPC Class Codes: C12P 7/54 Acetic acid vinegar C12J
• CPC Class Codes: C12Q 3/00 Condition responsive control processes apparatus therefor C12M1/36; controlling or regulating in general G05
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

Controlling the gas inlet flow rate and energy input to a fermentation reactor to maximize conversion of syngas by maximizing uptake of hydrogen into a medium relative to carbon dioxide and carbon monoxide based on determined volumetric mass transfer coefficients for hydrogen, carbon monoxide, and carbon dioxide.

Claims

1. A method of syngas fermentation comprising:

providing a continuously stirred tank reactor having a gas inlet, a gas outlet, and a variable speed agitator;

providing a liquid medium inside the continuously stirred tank reactor;

providing an autotrophic acetogenic bacteria in the medium;

initiating fermentation of a feed gas by supplying syngas comprising carbon monoxide and hydrogen gases via the gas inlet at a first gas flow rate while operating the agitator at a first speed;

detecting a concentration of hydrogen and a concentration of carbon monoxide from the gas outlet; and

continuing fermentation while operating the agitator at a second speed that is greater than the first speed when a decrease in concentration of hydrogen and a decrease in concentration of carbon monoxide is detected from the gas outlet.

2. The method of claim 1, further comprising further increasing the agitator speed from the second speed.

3. The method of claim 2, further comprising reducing the gas flow rate upon detecting an increase in concentration of hydrogen gas at the outlet.

4. A method of operating a fermentation reactor comprising:

providing a fermentation reactor having an gas inlet and a gas outlet and an energy input;

providing a liquid medium inside the continuously stirred tank reactor;

providing an autotrophic acetogenic bacteria in the medium;

providing a syngas into the gas inlet at a controlled rate;

determining a volumetric mass transfer coefficient for carbon monoxide in the liquid medium;

determining a volumetric mass transfer coefficient for hydrogen in the liquid medium;

determining a volumetric mass transfer coefficient for carbon dioxde in the liquid medium;

controlling the gas inlet flow rate and the energy input to maximize uptake of hydrogen into the medium relative to carbon dioxide and carbon monoxide based on the determined determined a volumetric mass transfer coefficients for hydrogen, carbon monoxide, and carbon dioxide, respectively.

5. The method of claim 4, wherein the volumetric mass transfer coefficients are determined utilizing the equation:

6. The method of claim 4, wherein the autotrophic acetogenic bacteria is Clostridium ragsdalei.

7. The method of claim 4, wherein the autotrophic acetogenic bacteria is Clostridium acetobutylicum.

8. The method of claim 4, wherein the autotrophic acetogenic bacteria is Clostridium beijerinckii.

9. The method of claim 4, wherein the autotrophic acetogenic bacteria is Clostridium ljungdahlii.

10. The method of claim 4, wherien the fermentation reactor is a continuously stirred tank reactor and the energy input is an agitator.

11. The method of claim 4, wherein the fermentation reactor is a packed column contactor and the energy input comprises pumping the medium.