Bioelectrosynthesis of organic compounds

Abstract

In some aspects, the present disclosure provides a method of bioelectric production of organic compounds such as acetate. In further aspects, the present disclosure also provides methods of producing a hydrocarbon based fuel using C02 as the carbon source.

What is claimed is: 
     
         1 . A method for bioelectric synthesis of H 2  and organic compounds comprising:
 (a) culturing a microbial population in a media in a cathode chamber of an electrochemical cell; and   (b) maintaining the microbial population in the cathode chamber in the presence of:
 (i) constant current of between 1.0 and 50 A per liter of cathode chamber volume; 
 (ii) CO 2  gas; and 
 (iii) a flow of media nutrients, 
   
       thereby producing organic compounds;
 (c) collecting the produced organic compounds. 
 
     
     
         2 . The method of  claim 1 , comprising maintaining the microbial population in the presence of between 1 and 20 A per liter of cathode chamber volume. 
     
     
         3 . The method of  claim 2 , comprising maintaining the microbial population in the presence of between 3 and 15 A per liter of cathode chamber volume. 
     
     
         4 . The method of  claim 1 , comprising maintaining the microbial population in the presence of a constant current for at least 10, 20, 30, 40, 50, 60, 120 or 180 days. 
     
     
         5 . The method of  claim 1 , comprising maintaining the microbial population in the presence of a constant current for 60 to 180 days. 
     
     
         6 . The method of  claim 1 , wherein the constant flow of media nutrients is filtered to maintain the cells of the microbial population in the cathode chamber. 
     
     
         7 . The method of  claim 1 , wherein the electrochemical cell further comprises a probe for measuring pH. 
     
     
         8 . The method of  claim 1 , wherein the media in the cathode chamber comprises a pH buffer system. 
     
     
         9 . The method of  claim 8 , wherein the pH buffer system is a phosphate or carbonate buffer system. 
     
     
         10 . The method of  claim 1 , further comprising maintaining the media in the cathode chamber at a pH of between 9.0 and 4.5. 
     
     
         11 . The method of  claim 10 , further comprising maintaining the media in the cathode chamber at a pH of between 7.0 and 4.5. 
     
     
         12 . The method of  claim 1 , wherein the flow of media nutrients is constant. 
     
     
         13 . The method of  claim 1 , wherein the flow of media nutrients is intermittent. 
     
     
         14 . The method of  claim 1 , wherein the CO 2  is provided by bicarbonate. 
     
     
         15 . The method of  claim 1 , wherein the cathode chamber is flushed with CO 2  periodically. 
     
     
         16 . The method of  claim 15 , wherein the cathode chamber is flushed with CO 2  on average every 3 to 10 days. 
     
     
         17 . The method of  claim 15 , wherein the cathode chamber is supplied with a continuous in flow of CO 2 . 
     
     
         18 . The method according to  claim 1 , wherein the CO 2  is obtained from waste gas or captured from the anaerobic digestion of waste. 
     
     
         19 . The method according to  claim 1 , wherein cathode chamber is maintained at a temperature of between 15 and 40° C. 
     
     
         20 . The method according to  claim 19 , wherein cathode chamber is maintained at a temperature of between 20 and 30° C. 
     
     
         21 . The method of  claim 1 , wherein the microbial population comprises at least about 50% acetogens. 
     
     
         22 . The method of  claim 1 , wherein the microbial population comprises  Acetobacterium woodii, Acetobacterium weiringae, Sporomusa ovata, Clostridium ljugdahlii, Clostridium autoethanogenum, Clostridium carboxydivorans  or a mixture thereof. 
     
     
         23 . The method of  claim 1 , wherein the microbial population comprises an essentially pure population of a single acetogen. 
     
     
         24 . The method of  claim 1 , wherein the microbial population comprises an essentially pure population of  Acetobacterium woodii, Acetobacterium weiringae, Sporomusa ovata, Clostridium ljugdahlii, Clostridium autoethanogenum , or  Clostridium carboxydivorans.    
     
     
         25 . The method of  claim 1 , wherein the microbial population comprises Bacteria from at least three families selected from the group consisting of Eubacteriaeae, Campylobacteraceae, Helicobacteraceae, Porphyromonadaceae, WCHB1-69, Spirochaetaceae, Deferribacteraceae, Rhodobacteraceae, Synergistaceae and Rhodocyclaceae. 
     
     
         26 . The method of  claim 1 , wherein the microbial population comprises Bacteria from the Helicobacteraceae, WCHB1-69, Spirochaetaceae, or Synergistaceae families. 
     
     
         27 . The method of  claim 1 , wherein the microbial population comprises bacteria from the genus  Acetobacterium, Sulfurospirillum, Wolinella, Paludibacter, Spirochaeta, Geovibrio, Desulfovibrio  or  Azovibrio.    
     
     
         28 . The method of  claim 1 , wherein the microbial population comprises bacteria from the genera  Acetobacterium, Sulfurospirillum  and, optionally, the family Rhodobacteraceae. 
     
     
         29 . The method of  claim 1 , wherein the microbial population comprises  Acetobacterium woodii, Acetobacterium weiringae, Sporomusa ovata, Clostridium ljungdahlii  and/or  Clostridium autoethanogenum.    
     
     
         30 . The method of  claim 1 , wherein the microbial population comprises  Acetobacterium  sp.,  Sulfurospirillum  sp., and  Desulfovibrio  sp. 
     
     
         31 . The method of  claim 1 , wherein the microbial population comprises at least 85%  Acetobacterium  sp. 
     
     
         32 . The method of  claim 1 , wherein the microbial population is essentially free of methanogenic organisms. 
     
     
         33 . The method of  claim 1 , wherein the cathode comprises reticulated vitreous carbon (RVC), carbon paper, carbon cloth, carbon felt, carbon wool, carbon foam, graphite, porous graphite, graphite powder, graphene, carbon nanotubes, electrospun carbon fibers, carbon coated stainless steel mesh, a conductive polymer, platinum, palladium, titanium, gold, silver, nickel, copper, tin, iron, cobalt, tungsten, stainless steel, and combinations thereof. 
     
     
         34 . The method of  claim 33 , wherein the cathode comprises RVC. 
     
     
         35 . The method of  claim 34 , wherein the RCV is coated with carbon nanotubes. 
     
     
         36 . The method of  claim 1 , wherein the cathode is a porous material. 
     
     
         37 . The method of  claim 36 , wherein the cathode comprises 10 to 1000 pores per inch (ppi). 
     
     
         38 . The method of  claim 36 , wherein the cathode comprises RVC having 10 to 1000 pores per inch (ppi). 
     
     
         39 . The method of  claim 38 , wherein the cathode comprises RVC having 10 to 100 pores per inch (ppi). 
     
     
         40 . The method of  claim 38 , wherein the cathode comprises RVC having 10 to 200 pores per inch (ppi). 
     
     
         41 . The method of  claim 1 , wherein the electrochemical cell comprises an anode composed of carbon paper, carbon cloth, carbon felt, carbon wool, carbon foam, graphite, porous graphite, graphite powder, graphene, carbon nanotubes, electrically conductive woven fabric, electrospun carbon fibers, a conductive polymer, platinum, palladium, titanium, gold, silver, nickel, copper, tin, iron, cobalt, cobalt phosphate, tungsten, stainless steel, coated titanium, a mixed metal oxide or a combination thereof. 
     
     
         42 . The method of  claim 41 , wherein the anode comprises a mixed metal oxide. 
     
     
         43 . The method of  claim 41 , wherein the anode is a coated titanium anode. 
     
     
         44 . The method of  claim 43 , wherein the anode is coated with a metal oxide. 
     
     
         45 . The method of  claim 43 , wherein the anode is coated with IrO 2  and/or Ta 2 O 5 . 
     
     
         46 . The method of  claim 1 , wherein waste productions and/or organic compounds are periodically removed from the media. 
     
     
         47 . The method of  claim 46 , wherein waste productions and/or organic compounds are continuously removed from the media. 
     
     
         48 . The method of  claim 1 , wherein organic compounds are purified by freeze concentration or electrodialysis. 
     
     
         49 . The method of  claim 1 , wherein the organic compounds comprise acetate, butyrate, isobutyrate, propionate, 3-hydroxypropionate, 3-hydroxybutyrate, formate or an alcohol. 
     
     
         50 . The method of  claim 49 , wherein the organic compounds comprise ethanol. 
     
     
         51 . The method of  claim 49 , wherein the organic compounds comprise acetate. 
     
     
         52 . The method of  claim 1 , further comprising separating struvite from the media. 
     
     
         53 . The method of  claim 1 , wherein the cathode chamber is essentially free of methyl reductase inhibitor. 
     
     
         54 . The method of  claim 1 , wherein the cathode chamber is essentially free of 2-bromoethanesulfonic acid (BESA) or 2-chloroethanesulfonic acid (CESA). 
     
     
         55 . A system configured to provide bioelectric synthesis of organic compounds in accordance with any one of  claims 1 - 54 .