1. A stable continuous method for producing ethanol from the anaerobic bacterial fermentation of a gaseous substrate, the method comprising:
culturing in a fermentation bioreactor anaerobic, acetogenic bacteria in a liquid nutrient medium and supplying to said bioreactor said gaseous substrate comprising at least one reducing gas selected from the group consisting of carbon monoxide and hydrogen; and
manipulating said bacteria in said bioreactor by reducing the redox potential, or increasing the NAD(P)H TO NAD(P) ratio, in the fermentation broth after said bacteria achieves a stable cell concentration in said bioreactor, wherein said free acetic acid concentration in said bioreactor is less than 5 gL free acid,
said culturing and manipulating steps causing said bacteria in said bioreactor to produce ethanol in a fermentation broth at a productivity greater than 10 gL per day and wherein both ethanol and acetate are produced in said fermentation broth in a ratio of ethanol to acetate ranging from 1:1 to 20:1.
2. The method according to claim 1, wherein said fermentation bioreactor comprises a growth reactor which feeds said fermentation broth to a second fermentation bioreactor in which most of said ethanol is produced.
3. The method according to claim 1, further comprising the steps of removing said fermentation broth from said bioreactor, distilling ethanol from said broth and recovering said ethanol.
4. The method according to claim 3, further comprising the steps of recycling water containing acetate from said distilling step back to the bioreactor.
5. The method according to claim 1, wherein said bacteria is selected from the group consisting of: Acetobacterium woodii, Butyribacterium methylotrophicum, Clostridium aceticum, C. acetobutylicium, C. thermoaceticum, Eubacterium limosum, Clostridium ljungdahlii, and Peptostreptococcus productus.
6. The method according to claim 5, wherein said Clostridium ljungdahlii is selected from the strains consisting of PETC, ERI2, O-52 and C-01.
7. The method according to claim 1, wherein said gaseous substrate is selected from the group consisting of (a) carbon monoxide, (b) carbon monoxide and hydrogen, (c) carbon dioxide and hydrogen, and (d) carbon monoxide, carbon dioxide and hydrogen.
8. The method according to claim 7, wherein said substrate additionally comprises nitrogen or methane.
9. The method according to claim 1, wherein said manipulating step further comprises altering at least one parameter selected from the group consisting of nutrient medium contents, nutrient feed rate, aqueous feed rate, operating pressure, operating pH, gaseous substrate contents, gas feed rate, fermentation broth agitation rate, product inhibition step, cell density, substrate inhibition and combinations thereof.
10. The method according to claim 9, wherein said manipulating step comprises raising the pH of said culture above 4.5.
11. The method according to claim 9, wherein said manipulating step comprises periodically purging bacterial cells from said bioreactor to a cell concentration less than said stable concentration that utilizes all reducing gas or nutrient substrates in said bioreactor.
12. The method according to claim 9, comprising increasing the aqueous feed rate when the free acetic acid portion of the acetate present in the fermentation broth exceeds 2 gL, thereby inhibiting any unwanted increase in the concentration of said free acetic acid.
13. The method according to claim 9, comprising reducing said gaseous substrate feed rate to eliminate excess carbon monoxide, to relieve substrate inhibition and maintain said productivity.
14. The method according to claim 9, wherein said agitation rate is reduced to eliminate excess carbon monoxide, to relieve substrate inhibition and maintain said productivity.
15. The method according to claim 9, wherein said manipulating step comprises supplying to said bioreactor said gaseous substrate comprising the reducing gas carbon monoxide at a rate of from 0.3 to 2 mmol COgram of dry cell of bacteria in said bioreactorminute.
16. The method according to claim 15, wherein said the amount of CO present in said bioreactor is greater than the amount required to maintain said bacteria at a stable bacterial concentration that would fully utilize the CO provided.
17. The method according to claim 15, wherein said the amount of CO present in said bioreactor maintains ethanol production in preference to acetate production.
18. The method according to claim 15, wherein said rate is in the range of 0.5 to 1.5 mmol COgram of dry cell of bacteria in said bioreactorminute.
19. The method according to claim 15, wherein said gaseous substrate further comprises an excess of hydrogen reducing gas relative to said carbon monoxide, wherein said excess hydrogen causes said bacteria to produce a high ethanol to acetate ratio in said fermentation broth.
20. The method according to claim 9, wherein said manipulating step comprises feeding into said fermentation bioreactor said nutrient medium comprising an amount of calcium pantothenate in a range of from 0.5 to 50 ggrams of dry cell of bacteria produced in said bioreactor.
21. The method according to claim 20, wherein said amount of calcium pantothenate is less than required to maintain said bacteria at a stable bacterial concentration that would fully utilize the calcium pantothenate provided.
22. The method according to claim 20, wherein said amount of calcium pantothenate maintains ethanol production in preference to acetate production.
23. The method according to claim 20, wherein said amount is from 1 to 25 g calcium pantothenategrams of dry cell of bacteria produced.
24. The method according to claim 20, wherein said amount is from 2 to 25 g calcium pantothenategrains of dry cell of bacteria produced.
25. The method according to claim 20, further comprising the step of preventing acclimation of said bacteria in said bioreactor to said calcium pantothenate amount by maintaining a constant calcium pantothenate concentration and adjusting the parameters selected from the group consisting of gas rate, liquid rate, agitation rate and hydrogen gas partial pressure.
26. The method according to claim 20, further comprising supplying excess hydrogen reducing gas to said bioreactor prior to providing said amount of calcium pantothenate.
27. The method according to claim 9, wherein said manipulating step comprises feeding into said fermentation bioreactor said nutrient medium comprising an amount of cobalt in a range of from 5 to 100 g cobaltgrams of dry cell of bacteria produced in said bioreactor.
28. The method according to claim 27, wherein said amount of cobalt is less than required to maintain said bacteria at a stable bacterial concentration that would fully utilize the cobalt provided.
29. The method according to claim 27, wherein said amount of cobalt maintains ethanol production in preference to acetate
30. The method according to claim 27, wherein said amount is from 20 to 50 g calcium pantothenategrams of dry cell of bacteria produced.
31. The method according to claim 27, further comprising the step of preventing acclimation of said bacteria in said bioreactor to said amount of cobalt by maintaining a constant cobalt concentration and adjusting the parameters selected from the group consisting of gas rate, liquid rate, agitation rate and hydrogen gas partial pressure.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A system for aerosol capture comprising:
an aerosol gathering chamber configured to pass an aerosol through a material in a bulk liquid phase disposed within the aerosol gathering chamber to gather at least a portion of one or more components of the aerosol.
2. The system of claim 1, wherein the gathered portion of the one or more aerosol components comprises at least a hydrocarbon compound.
3. The system of claim 1, wherein the gathered portion of the one or more aerosol components comprises at least a component of a liquid hydrocarbon.
4. The system of claim 1, wherein the material in the bulk liquid phase includes a liquid hydrocarbon.
5. The system of claim 1, wherein the material in the bulk liquid phase includes water.
6. The system of claim 1, wherein the material in the bulk liquid phase is temperature-controlled.
7. The system of claim 1, further comprising one or more lengths of tubing in a spiral configuration containing the material in the bulk liquid phase to increase a path length through the material in the bulk liquid phase.
8. The system of claim 1, further comprising one or more augers disposed within the aerosol gathering chamber to increase a path length through the material in the bulk liquid phase.
9. The system of claim 1, further comprising one or more distilling systems coupled with the aerosol gathering chamber to distill all or part of the gathered portions of the one or more aerosol components.
10. The system of claim 9, further comprising one or more couplers configured to couple one or more of the one or more distillers to the aerosol gathering chamber to augment the material in the bulk liquid phase with all or part of the distilled gathered portions of the one or more aerosol components.
11. The system of claim 1, further comprising a mesh of a solid material disposed within the aerosol gathering chamber configured to increase the area of contact between the aerosol and the material in the bulk liquid phase and through which the aerosol and material in the bulk liquid phase are passed.
12. The system of claim 1, further comprising a plurality of baffles disposed within the aerosol gathering chamber configured to increase a path length through the material in the bulk liquid phase.
13. The system of claim 12, further comprising a mesh of solid material disposed around the plurality of baffles within the aerosol gathering chamber configured to increase the area of contact between the aerosol and the material in the bulk liquid phase and through which the aerosol and material in the liquid phase are passed.
14. The system of claim 1, further comprising one or more ports coupled with the aerosol gathering chamber to allow removal of water from the aerosol gathering chamber.
15. The system of claim 1, further comprising one or more ports coupled with the aerosol gathering chamber to allow removal of a portion of at least the portion of the one or more gathered aerosol components from the aerosol gathering chamber.
16. The system of claim 1, further comprising one or more aerosol production chambers coupled with the aerosol gathering chamber.
17. The system of claim 16, wherein the one or more aerosol production chambers comprises an aerosol production chamber producing at least a hydrocarbon compound or a component of a liquid hydrocarbon.
18. The system of claim 17, wherein the aerosol comprising at least the hydrocarbon compound or the component of the liquid hydrocarbon is produced from biomass.
19. The system of claim 17, wherein the hydrocarbon compound or the component of the liquid hydrocarbon comprises at least a hydrocarbon fuel.
20. The system of claim 17, wherein the hydrocarbon compound or the component of a liquid hydrocarbon comprises at least a hydrocarbon chemical.