Use of oxyhydrogen microorganisms for non-photosynthetic carbon capture and conversion of inorganic and / or c1 carbon sources into useful organic compounds

Abstract

To provide compositions and methods for a hybrid biological and chemical process that captures and converts carbon dioxide and / or other forms of inorganic carbon and / or C1 carbon sources (including but not limited to carbon monoxide, methane, methanol, formate, or formic acid, for example) and / or mixtures containing C1 chemicals (including but not limited to various syngas compositions, for example) into organic chemicals (biofuels or other valuable biomass, chemical, industrial, or pharmaceutical products.SOLUTION: The present invention, in certain embodiments, fixes inorganic carbon or C1 carbon sources into longer carbon chain organic chemicals by utilizing microorganisms capable of performing the oxyhydrogen reaction and the autotrophic fixation of CO2 in one or more steps of the process.SELECTED DRAWING: None

Description

[Technical field]

[0001] Related Applications This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 61 / 328,184, filed April 27, 2010, entitled "USE OF ACID-HYDROGEN MICROORGANISMS FOR THE RECOVERY AND CONVERSION OF NON-PHOTOSYNTHETIC CARBON FROM INORGANIC SOURCES TO VALUABLE ORGANIC COMPOUNDS." This application is also a continuation-in-part of International Patent Application PCT / US2010 / 001402, filed May 12, 2010, entitled "Biochemical Process Using Chemoautotrophic Microorganisms for the Chemofixation of Carbon Dioxide and / or Other Inorganic Carbon Sources to Organic Compounds and the Production of Other Useful Products," which is a continuation-in-part of U.S. Patent Application Serial No. 12 / 613,550, filed November 6, 2009, entitled "Biochemical Process Using Chemoautotrophic Microorganisms for the Chemofixation of Carbon Dioxide and / or Other Inorganic Carbon Sources to Organic Compounds and the Production of Other Useful Products," which claims the benefit of U.S. Provisional Patent Application Serial No. 61 / 111,794, filed November 6, 2008, entitled "Biochemical Process Using Chemoautotrophic Microorganisms for the Chemofixation of Carbon Dioxide and Other Inorganic Carbon Sources to Biofuels and Other Useful Products by Carbon Cycling," each of which is incorporated herein by reference in its entirety for all purposes. [Background technology]

[0002] The present invention belongs to the technical fields of biofuels, bioremediation, carbon capture, carbon dioxide to fuel, carbon cycle, carbon sequestration, energy storage, gas to liquids, waste to energy, syngas conversion, and renewable / alternative energy and / or low carbon emission source energy. In particular, the present invention is a unique example of the use of biocatalysts in biochemical processes that fix carbon dioxide and / or other forms of inorganic carbon sources and / or other C1 carbon sources to longer carbon chain organic chemicals in a non-photosynthetic process powered by low carbon emission energy sources and / or waste to energy sources. In addition, the present invention encompasses the production of chemical co-products that are co-fed by carbon fixation and / or non-biological reaction steps as part of the total carbon capture and conversion process or syngas conversion process. The present invention may enable the efficient and economical capture of carbon dioxide from the atmosphere or from carbon dioxide point emission sources, as well as the economical use of waste to energy sources and / or renewable and / or low carbon emission energy sources to produce liquid transportation fuels and / or other organic chemicals. This will help combat climate change caused by greenhouse gases and contribute to domestic production of renewable liquid fuels for transportation and / or other organic chemicals that do not depend in any way on agriculture.

[0003] There has been a great deal of interest and effort in developing technologies that use renewable or waste-based energy for the conversion of carbon dioxide or other low-value carbon sources into useful organic chemicals to provide alternatives to chemicals, materials, and fuels derived from petroleum or other fossil sources. In the area of ​​CO2 conversion, most of the emphasis has been on biological methods using photosynthesis to fix CO2 into biomass or end products, while there has also been some effort in completely abiotic chemical processes to fix CO2.

[0004] A type of CO2 organic synthesis approach that has received relatively little attention is the hybrid chemical / biological process, where the biological step is limited to CO2 fixation corresponding to the dark reaction of photosynthesis. Potential advantages of such hybrid CO2 organic synthesis processes include the ability to combine CO2 fixation enzyme functions acquired through billions of years of evolution with a wide set of abiotic technologies such as solar PV, solar thermal, wind, geothermal, hydroelectric, or nuclear power to power the process. Microorganisms that fix carbon without light can be confined to more controlled and protected environments that are less susceptible to water and nutrient losses, pollution, and weather hazards than those available for the cultivation of photosynthetic microorganisms. Furthermore, increased bioreactor capacity can be accommodated in a vertical rather than horizontal configuration, which may allow for more efficient land use. Hybrid chemical / biological systems offer the possibility of a CO2 organic synthesis process that retains the biological functions of complex organic synthesis from CO2 while avoiding many of the drawbacks of photosynthesis.

[0005] Chemoautotrophs are generally microorganisms that can fix CO2 as well as photosynthetic dark reactions, but they can obtain the reducing equivalents required for CO2 fixation from external sources and do not need to generate them internally via photosynthetic light reactions. Carbon fixation biochemical pathways carried out by chemoautotrophs include the reductive tricarboxylic acid cycle, the Calvin-Benson-Bassham cycle, and the Wood-Ljungdahl pathway. Summary of the Invention [Problem to be solved by the invention]

[0006] Prior work is known regarding the specific application of chemoautotrophic microorganisms in the capture and conversion of CO2 gas to fixed carbon. However, many of these have suffered from drawbacks that limit the effectiveness, economic feasibility, practicality, and commercialization of the described processes. The present invention, in certain embodiments, addresses one or more of the above-listed drawbacks. [Means for solving the problem]

[0007] The present invention, utilizing oxyhydrogen microorganisms for chemosynthetic fixation of CO2 under carefully controlled oxygen levels, is believed to have advantages in producing long chain organic compounds (e.g., C5 and above). The ability to produce long chain organic compounds is an important advantage of the present invention, since the energy density (energy per unit volume) is generally higher for long chain organic compounds, and compatibility with current transportation systems is generally greater for long chain organic compounds versus short chain products, such as C1 and C2 products.

[0008] In response to a need in the art recognized by the inventors in making the present invention, a novel combined biochemical process is described for the capture and conversion of inorganic and / or C1 carbon sources to long chain organic compounds, particularly those with chain lengths of C5 and above, via the use of oxyhydrogen microorganisms for carbon capture and fixation. In some embodiments, the process can combine the efficient production of high value organic compounds, such as liquid hydrocarbon fuels, with waste disposal of waste carbon sources and even CO2 capture, which can provide additional revenue streams.

[0009] In one aspect, a biochemical method for the recovery and conversion of inorganic carbon compounds and / or organic compounds containing only one carbon atom to organic chemicals is described. In some embodiments, the method includes introducing the inorganic carbon compounds and / or organic compounds containing only one carbon atom into an environment suitable for supporting oxyhydrogen microorganisms and / or capable of supporting extracts of oxyhydrogen microorganisms, and converting the inorganic carbon compounds and / or organic compounds containing only one carbon atom to organic chemicals and / or precursors thereof in the environment via at least one chemosynthetic carbon fixation reaction utilizing oxyhydrogen microorganisms and / or cell extracts containing enzymes from oxyhydrogen microorganisms. In some embodiments, the chemosynthetic fixation reaction is driven, at least in part, by chemical and / or electrochemical energy provided by electron donors and electron acceptors that are chemically and / or electrochemically generated and / or introduced into the environment from at least one external source outside the environment.

[0010] In one aspect, a bioreactor is described. The bioreactor, in one group of embodiments, includes a first tower including an upper portion and a lower portion, and a second tower including an upper portion and a lower portion, the upper portion of the second tower being fluidly connected to the upper portion of the first tower, and the lower portion of the second tower being fluidly connected to the lower portion of the first tower. In some embodiments, the bioreactor is constructed and arranged such that a volume of gas is substantially constant at the top of the first tower and / or the second tower when liquid is circulated between the first and second towers. In some embodiments, the volume of gas occupies at least about 2% of the total volume of the tower in which it is located.

[0011] In another aspect, a method of operating a bioreactor is provided that, in some embodiments, comprises circulating a liquid comprising a growth medium between a first column and a second column, wherein during operation, a volume of gas is maintained substantially constant at the top of the first column and / or the second column, and the volume of gas occupies at least about 2% of the total volume of the column in which it is located.

[0012] In one aspect, an electrolysis device is provided, which in some embodiments includes a chamber constructed and arranged to electrolyze water to produce oxygen and hydrogen, and an outlet including a separator constructed and arranged to separate at least a portion of the oxygen in the stream from at least a portion of the hydrogen in the stream such that the hydrogen content of the fluid exiting the separator is suitable for use as a feed stream to a reactor containing a culture of an oxyhydrogen microorganism.

[0013] In another aspect, a method of operating an electrolysis apparatus is described that, in some embodiments, includes electrolyzing water to produce a first stream containing oxygen and hydrogen, and separating at least a portion of the oxygen from at least a portion of the hydrogen to produce a second stream that is relatively hydrogen-rich compared to the first stream, where the second stream is suitable as a feed stream to a reactor containing a culture of an oxyhydrogen microorganism.

[0014] The present invention provides, in certain embodiments, compositions and methods for recovering carbon dioxide from carbon dioxide-containing gas streams and / or atmospheric carbon dioxide or dissolved, liquefied, or chemically bound carbon dioxide via biochemical processes utilizing obligate or facultative oxyhydrogen microorganisms and / or cell extracts containing enzymes from oxyhydrogen microorganisms in one or more carbon fixation process steps.

[0015] The present invention, in certain embodiments, provides compositions and methods for utilizing a C1 carbon source (e.g., but not limited to, carbon monoxide, methane, methanol, formate, or formic acid) and / or a mixture containing C1 chemicals (e.g., but not limited to, various syngas compositions produced from various fixed carbon feedstocks that have been gasified, pyrolyzed, or steam reformed) to convert said C1 chemicals into long chain organic compounds.

[0016] The invention provides, in certain embodiments, compositions and methods for the recovery, processing, and use of organic compounds produced by the fixation of inorganic and / or C1 carbon sources into long-chain organic compounds by chemosynthetic reactions performed by oxyhydrogen microorganisms. The invention provides, in certain embodiments, compositions and methods for the maintenance and control of oxygen levels in a carbon fixing environment for improved (e.g., optimal) production of C5 and higher organic compound products via carbon fixation. The invention provides, in certain embodiments, compositions and methods for the production, processing, and delivery of chemical nutrients required for carbon fixation and the maintenance of oxyhydrogen microbial cultures (e.g., including but not limited to, providing electron donors and electron acceptors required for non-photosynthetic carbon fixation). The invention provides, in certain embodiments, compositions and methods for the maintenance of an environment conducive to carbon fixation and the recovery and recycling of unused chemical nutrients and process water.

[0017] The invention, in certain embodiments, involves chemical process steps that are performed in series and / or in parallel with the chemosynthetic reaction steps, namely, converting unrefined crude input chemicals into more refined chemicals suitable for supporting the chemosynthetic carbon fixation step; converting energy inputs into a chemical form that can be used to drive chemosynthesis, specifically chemical energy in the form of electron donors and electron acceptors; directing inorganic carbon recovered from industrial, atmospheric, or aquatic sources to the carbon fixation step of the process under conditions suitable to support chemosynthetic carbon fixation by oxyhydrogen microorganisms or enzymes; and / or directing carbon monoxide, methyl ether, and / or methyl ether, which can be used by oxyhydrogen microorganisms as a carbon source and optionally an energy source for synthesizing long chain organic chemicals. Compositions and methods are provided for directing C1 chemicals and / or mixtures containing C1 chemicals derived from low-value or waste carbon sources such as ethane, methanol, formate, or formic acid (including, but not limited to, various syngas compositions derived from gasification, pyrolysis, or steam reforming of various low-value or waste carbon sources), and further processing the output products of the carbon fixation step into a form suitable for storage, transport, and sale, and / or safe disposal, to result in a net reduction in gaseous CO2 released to the atmosphere and / or upgrading of low-value or waste materials into finished chemicals, fuels, or nutrients. The fully chemical process steps combined with the chemical synthesis carbon fixation step constitute an all-carbon capture and conversion process according to some embodiments of the invention.

[0018] A feature of certain embodiments of the invention is the incorporation of one or more process steps within a chemical process for the recovery and conversion of inorganic carbon to fixed carbon products utilizing oxyhydrogen microorganisms and / or enzymes from oxyhydrogen microorganisms as biocatalysts for the fixation of carbon dioxide and / or inorganic carbon in dissolved or solid form in a carbon dioxide-containing gas stream or in the atmosphere or water to organic compounds. In some such embodiments, inorganic carbon as dissolved carbon dioxide, carbonate ions, or bicarbonate ions in solution, including carbon dioxide-containing flue gas, or process gas, or air, or aqueous solutions such as seawater, or inorganic carbon in the solid phase (e.g., but not limited to, carbonates and bicarbonates) is pumped or otherwise added to a tank or enclosed vessel containing the nutrient medium and the oxyhydrogen microorganisms. In some such cases, the oxyhydrogen microorganisms use chemical energy stored in molecular hydrogen, and / or valence or conduction electrons in the solid electrode material, and / or one or more of the following electron donors pumped or otherwise provided in the nutrient medium: ammonia, ammonium, carbon monoxide, dithionite, elemental sulfur, hydrocarbons, sulfates such as metabisulfite, nitric oxide, nitrite, thiosulfate (e.g., but not limited to, sodium thiosulfate (NaSO) or calcium thiosulfate (CaSO)), sulfides such as hydrogen sulfide, sulfite, thionate, thionite, transition metals or their sulfides, oxides, chalcogenides, halides, hydroxides, oxyhydroxides, phosphates, sulfates, or carbonates in the soluble or solid phase to perform chemical synthesis to fix inorganic carbon into organic compounds. In some embodiments, electrons in the conduction or valence bands in the solid electrode material can be used. The electron donor can be oxidized by the electron acceptor in a chemical synthesis reaction.Electron acceptors that may be used in the chemical synthesis reaction steps include oxygen and / or other electron acceptors (such as, but not limited to, one or more of the following: carbon dioxide, ferric or other transition metal ions, nitrates, nitrites, sulfates, oxygen, or valence or conduction band holes in a solid electrode material).

[0019] A feature of certain embodiments of the present invention is the incorporation of one or more process steps within a chemical process for the conversion of C1 carbon sources (e.g., but not limited to, carbon monoxide, methane, methanol, formate, or formic acid) and / or mixtures containing C1 chemicals (e.g., but not limited to, various syngas compositions produced from various fixed carbon feedstocks that have been gasified, pyrolyzed, or steam reformed) utilizing oxyhydrogen microorganisms and / or enzymes from oxyhydrogen microorganisms as biocatalysts for the conversion of C1 chemicals to longer chain organic chemicals (i.e., C2 and higher, and in some embodiments, C5 and higher carbon chain molecules). In some such embodiments, C1-containing syngas, or process gas, or C1 chemicals in pure liquid form or dissolved in solution, are pumped or otherwise added to a tank or closed vessel containing the nutrient medium and the oxyhydrogen microorganisms. In some such cases, the oxyhydrogen microorganisms use chemical energy stored in the C1 chemicals and / or molecular hydrogen, and / or valence or conduction electrons in the solid electrode material, and / or one or more of the following electron donors pumped or otherwise provided in the nutrient medium: ammonia, ammonium, carbon monoxide, dithionite, elemental sulfur, hydrocarbons, sulfates such as metabisulfite, nitric oxide, nitrite, thiosulfate (e.g., but not limited to, sodium thiosulfate (NaSO) or calcium thiosulfate (CaSO)), sulfides such as hydrogen sulfide, sulfite, thionate, thionite, transition metals or their sulfides, oxides, chalcogenides, halides, hydroxides, oxyhydroxides, sulfates, or carbonates in the soluble or solid phase to biosynthesize the C1 chemicals into longer carbon chain organic chemicals. The electron donor can be oxidized by the electron acceptor in a chemical synthesis reaction.Electron acceptors that may be used in this reaction step include oxygen and / or other electron acceptors (such as, but not limited to, one or more of the following: carbon dioxide, ferric or other transition metal ions, nitrates, nitrites, oxygen, or holes in the solid electrode material).

[0020] The process's chemical synthesis reaction step(s), in which carbon dioxide and / or inorganic carbon is fixed to organic compounds and organic carbon in the form of biomass, and / or the reaction step converting C1 chemicals to long chain organic chemicals, in which C1 chemicals (e.g., but not limited to, carbon monoxide, methane, methanol, formate, or formic acid) and / or mixtures containing C1 chemicals (e.g., but not limited to, various syngas compositions produced from various fixed carbon feedstocks that have been gasified, pyrolyzed, or steam reformed) are biochemically converted to long chain organic chemicals (i.e., C2 and higher, and in some embodiments C5 and higher carbon chain molecules), can be carried out under aerobic, microaerobic, anoxic, anaerobic, or facultative conditions. Facultative environments are considered to be those having an aerobic overlayer and an anaerobic underlayer resulting from stratification of the water column.

[0021] Oxygen levels are controlled in some embodiments of the invention to control (e.g., optimize) the production of target organic compounds by oxyhydrogen microorganisms via carbon fixation. One purpose of controlling oxygen levels is to control (e.g., optimize) intracellular adenosine triphosphate (ATP) concentrations via cellular reduction of oxygen and production of ATP by oxidative phosphorylation, while at the same time keeping the environment sufficiently reducing so that a high ratio of NADH (or NADPH) to NAD (or NADP) is also maintained.

[0022] The advantage of using oxyhydrogen microorganisms over strictly anaerobic acetogenic or methanogenic microorganisms for carbon capture and / or syngas conversion applications is the higher oxygen tolerance of oxyhydrogen microorganisms.

[0023] An additional advantage of using acidohydrogen microorganisms over acetogenic bacteria for carbon capture applications and / or syngas conversion applications and / or biofuel production is that the production of ATP powered by the acidohydrogen reaction results in a water product that can be easily incorporated into the process stream, rather than the generally undesirable acidogenic acetate and butyrate products that can harm the microorganisms by lowering the solution pH or accumulating to toxic levels.

[0024] Further features of certain embodiments of the present invention relate to the source, generation, or recycling of electron donors used by oxyhydrogen microorganisms to fix carbon dioxide to organic compounds and / or synthesize longer carbon chain organic molecules from C1 chemicals. In certain embodiments of the present invention, the electron donors used for carbon dioxide capture and carbon fixation can be electrochemically or thermochemically generated or recycled using power based on a wide variety of renewable and / or low carbon emission energy technologies, including, but not limited to, photovoltaic, solar, wind, hydroelectric, nuclear, geothermal, enhanced geothermal, ocean thermal, wave, and tidal power. The electron donors can also be of mineral origin, including, but not limited to, minerals containing reduced S and Fe. The electron donors used in certain embodiments of the present invention can also be generated or recycled via chemical reactions with hydrocarbons, which may or may not be non-renewable fossil fuels, provided that said chemical reactions produce little or no carbon dioxide gas emissions. For example, an oxide reduction reaction that produces carbonate and hydrogen products that can be used as electron donors in a carbon fixation reaction step according to certain embodiments of the present invention is: 2CH4+Fe2O3+3H2O→2FeCO3+7H2 and / or CH4+CaO+2H2O→CaCO3+4H2 Includes.

[0025] A further feature of certain embodiments of the present invention relates to the formation and recovery of organic compounds and / or biomass from one or more chemosynthetic carbon fixation processes. These organic compounds and / or biomass products may have a variety of uses.

[0026] Further features of certain embodiments of the present invention relate to the use of modified oxyhydrogen microorganisms in one or more carbon fixation processes to produce superior quantities and / or quality of organic compounds, biochemicals, or biomass via chemical synthesis. The oxyhydrogen microorganisms used in these processes can be modified via artificial means, including, but not limited to, accelerated mutagenesis (e.g., using ultraviolet light treatment or chemical treatment), genetic engineering or genetic modification, hybridization, synthetic biology, or traditional selective breeding. Possible modifications of oxyhydrogen microorganisms include, but are not limited to, those aimed at the production of increased quantities and / or quality of organic compounds and / or biomass to be used as biofuels or as feedstocks for producing biofuels (e.g., including, but not limited to, JP-8 jet fuel, diesel, gasoline, biodiesel, butanol, ethanol, hydrocarbons, methane, and simulated vegetable oils, or any other hydrocarbon suitable for use as a renewable / alternative fuel that results in reduced greenhouse gas emissions).

[0027] Also described are compositions and methods for reducing the risk of gas fermentation utilizing mixtures of hydrogen and oxygen within the processes of the present invention.

[0028] Also described are compositions and methods that take advantage of the oxygen tolerance and ability of oxyhydrogen microorganisms to use oxygen as an electron acceptor to enable a system for converting water to hydrogen or hydride electron donors and oxygen electron acceptors with improved efficiency over the application of current state-of-the-art electrolysis to generate hydrogen or hydride electron donors and oxygen electron acceptors.

[0029] Also described are process steps for the recovery and further processing of valuable chemicals produced in both the biological carbon fixation step of the process as well as the non-biological process steps.

[0030] Other advantages and novel features of the present invention will become apparent from the following detailed description of various non-limiting embodiments of the invention when considered in conjunction with the accompanying drawings. All publications, patent applications, and patents mentioned herein are incorporated by reference in their entirety. In the event that the specification and the documents incorporated by reference contain conflicting and / or inconsistent disclosure, the specification shall control.

[0031] Embodiments of the present invention are described by way of example, and not by way of limitation, with reference to the accompanying drawings, which are schematic and are not intended to be drawn to scale. For purposes of clarity, not every element is shown in every figure, and not every element of every embodiment of the invention is shown unless illustration is necessary for a person skilled in the art to understand the invention. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a general process flow diagram of one embodiment of the present invention for a carbon capture and sequestration process. [Diagram 2] FIG. 1 is a process flow diagram of another embodiment of the invention with CO capture performed by a microorganism (e.g., hydrogen-oxidizing purple non-sulfur bacteria) capable of performing an oxyhydrogen reaction to produce lipid-rich biomass that is converted into JP-8 jet fuel. [Diagram 3] FIG. 1 is a schematic of a bioreactor design that can avoid dangerous mixing of hydrogen and oxygen by taking advantage of the low solubility of hydrogen and oxygen gases in water and providing the oxygen and hydrogen needed for cellular energy and carbon fixation to the oxyhydrogen microorganisms. [Figure 4]FIG. 2 is a schematic of a bioreactor design that takes advantage of the relatively high solubility of carbon dioxide and the ability of oxyhydrogen microorganisms to capture carbon dioxide from relatively dilute streams using a carbon concentrating mechanism (CCM) to remove CO2 from dilute gas mixtures and separate low solubility gases such as oxygen and nitrogen from them. [Diagram 5] It is an electrolysis technology specifically designed to take advantage of the tolerance and requirement of oxyhydrogen microorganisms for specific oxygen concentrations by reducing the complete separation of produced hydrogen and oxygen from standard electrolysis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The present invention provides, in certain embodiments, compositions and methods for the capture and fixation of carbon dioxide from carbon dioxide-containing gas streams and / or atmospheric carbon dioxide or carbon dioxide in liquefied or chemically bound form via biochemical processes utilizing obligate or facultative oxyhydrogen microorganisms and / or cell extracts containing enzymes from oxyhydrogen microorganisms in one or more process steps. Also described is the fixation of inorganic carbon sources other than CO2 and / or other C1 carbon sources. Cell extracts include, but are not limited to, lysates, extracts, fractions, or purified products exhibiting chemosynthetic enzyme activity that can be produced by standard methods from oxyhydrogen microorganisms. In addition, the present invention provides, in certain embodiments, compositions and methods for the recovery, processing, and use of chemical products of one or more chemosynthetic reaction steps performed by oxyhydrogen microorganisms to fix inorganic carbon into organic compounds and / or one or more synthetic reaction steps performed by oxyhydrogen microorganisms to elongate C1 molecules into longer carbon chain organic chemicals. Finally, the present invention provides, in certain embodiments, compositions and methods for the generation, processing and delivery of chemical nutrients required for chemoautotrophic carbon fixation by oxyhydrogen microorganisms, specifically electron donors, including, but not limited to, molecular hydrogen and / or electricity, and electron acceptors, including, but not limited to, oxygen and carbon dioxide, to drive the carbon fixation reactions, compositions and methods for maintaining an environment conducive to carbon fixation by oxyhydrogen microorganisms, and compositions and methods for the removal of chemical products of chemosynthesis from the oxyhydrogen culture environment and the recovery and recycling of unused portions of the chemical nutrients.

[0034] The terms "molecular hydrogen," "dihydrogen," and "H2" are used interchangeably throughout.

[0035] The terms "oxyhydrogen microorganism" and "oxyhydrogen microorganism" are used synonymously throughout. Oxyhydrogen microorganisms are reviewed in Chapter 5, Section III of the book "Thermophilic Bacteria" by Jakob Kristjansson, CRC Press, 1992, which is incorporated herein by reference. Generally, oxyhydrogen microorganisms are capable of carrying out oxyhydrogen reactions. Oxyhydrogen microorganisms generally have the ability to utilize molecular hydrogen by utilizing hydrogenase, where some of the electrons donated from H2 are converted to NAD + (and / or other intracellular reducing equivalents), and the remainder of the electrons are available for aerobic respiration. In addition, oxyhydrogen microorganisms are generally capable of autotrophically fixing CO2 via pathways such as the reverse Calvin cycle and the reverse citric acid cycle.

[0036] Additionally, the terms "oxyhydrogen reaction" and "detonation reaction" are used interchangeably throughout to refer to the microbial oxidation of molecular hydrogen with molecular oxygen. 2H2+O2→2H2O+Energy and / or by the stoichiometric equivalent equation for this reaction.

[0037] Exemplary acidohydrogen microorganisms that can be used in one or more process steps according to certain embodiments of the present invention include the following: purple non-sulfur photosynthetic bacteria (e.g., Rhodopseudomonas palustris, Rhodopseudomonas capsulata, Rhodopseudomonas viridis, Rhodopseudomonas sulfoviridis, Rhodopseudomonas blastica, Rhodopseudomonas spheroides, Rhodopseudomonas acidophila, Rhodopseudomonas naphthalene ... acidophila, and other Rhodopseudomonas species, Rhodospirillum rubrum and other Rhodospirillum species, Rhodococcus opacus and other Rhodococcus species, Rhizobium japonicum and other Rhizobium species, Thiocapsa roseopersicina and other Thiocapsa species, Pseudomonas hydrogenovora, Pseudomonas hydrogenothermophila, Pseudomonas hydrogenothermophila, and other Pseudomonas species, Hydrogenomonas pantotropha, Hydrogenomonas eutropha, Hydrogenomonas facilis,facilis, and other Hydrogenomonas species, Hydrogenobacter thermophilus and other Hydrogenobacter species, Hydrogenovibrio marinus and other Hydrogenovibrio species, Helicobacter pylori and other Helicobacter species, Xanthobacter species, Hydrogenophaga species, Bradyrhizobium japonicum and other Bradyrhizobium species, Ralstonia eutropha eutropha and other Ralstonia species, Alcaligenes eutrophus and other Alcaligenes species, Variovorax paradoxus and other Variovorax species, Acidovorax facilis and other Acidovorax species, cyanobacteria (e.g., Anabaena oscillarioides, Anabaena spiroides, Anabaena cylindrica, and other Anabaena species), green algae (e.g., Scenedesmus obliquus, obliquus and other Scenedesmus species, Chlamydomonas reinhardtiireinhardii and other Chlamydomonas species, Ankistrodesmus species, Rhaphidium polymorphium and other Rhaphidium species, as well as a consortium of microorganisms including oxyhydrogen microorganisms.

[0038] Various oxyhydrogen microorganisms that can be used in certain embodiments of the present invention can be native to a range of environments, including, but not limited to, hydrothermal vents, geothermal vents, hot springs, cold seeps, underground aquifers, salt lakes, saline formations, mines, acid mine drainage, mine tailings, oil wells, refinery wastewater, oil, gas, or hydrocarbon contaminated waters, coal seams, deep underground formations, wastewater and sewage treatment plants, geothermal power plants, sulfur vent fields, soils (e.g., soils contaminated with hydrocarbons and / or soils located under or around oil or gas wells, oil refineries, oil pipelines, gas stations), and may or may not be extremophiles, including, but not limited to, thermophiles, hyperthermophiles, acidophiles, halophiles, and psychrophiles.

[0039] In some embodiments, it is possible to produce relatively long chain chemical products. For example, organic chemicals produced in some embodiments may include compounds with carbon chain lengths of at least C5, at least C10, at least C15, at least C20, from about C5 to about C30, from about C10 to about C30, from about C15 to about C30, or from about C20 to about C30.

[0040] FIG. 1 shows a general process flow diagram of an embodiment of the present invention having process steps of generating an electron donor (e.g., molecular hydrogen electron donor) suitable for supporting chemical synthesis from energy input and crude inorganic chemical input, followed by recovery of chemical co-products from the electron donor generation step, delivery of the generated electron donor along with oxygen electron acceptor, water, nutrients, and CO2 from an industrial flue gas point source to one or more chemical synthesis reaction steps that utilize oxyhydrogen microorganisms to capture and fix carbon dioxide and generate chemical and biomass co-products via chemical synthesis reactions, followed by process steps of recovering both chemical and biomass products from the process stream, and recycling unused nutrients and process water as well as cell mass required to sustain the microbial culture back to the carbon fixation reaction step.

[0041] In the embodiment illustrated in FIG. 1, CO2-containing flue gas is recovered from a point source or emission source. Electron donors (e.g., H2) required for chemical synthesis can be generated from input inorganic chemicals and energy. The flue gas can be pumped into a bioreactor containing oxyhydrogen microorganisms along with the electron donors and electron acceptors required to drive chemical synthesis and a suitable medium for supporting microbial culture and carbon fixation via chemical synthesis. The cell culture can be continuously flowed in and out of the bioreactor. After the cell culture leaves the bioreactor, the cell mass can be separated from the liquid medium. The cell mass required to replenish the cell culture mass at a desired (e.g., optimal) level can be recycled back to the bioreactor. The excess cell mass can be dried to form a dry biomass product, which can be further processed into various chemicals, fuels, or nutrients. Following the cell separation step, the extracellular chemical products of the chemical synthesis reaction can be removed from the process flow and recovered. Any undesirable waste products that may be present are then removed. The liquid medium and any unused nutrients can then be recirculated back to the bioreactor.

[0042] Reduced inorganic chemicals (e.g., H2, H2S, ferrous iron, ammonium, Mn) that support the growth of chemoautotrophic organisms 2+ ), many of which can be readily produced using electrochemical and / or thermochemical processes known in the chemical engineering arts, which processes can optionally be powered by a variety of carbon dioxide or low carbon emission and / or renewable power sources, including wind, hydroelectric, nuclear, photovoltaic, or solar thermal.

[0043] In certain embodiments of the invention, carbon dioxide-free or low-carbon emission and / or renewable power sources are used to generate the electron donor, including, but not limited to, one or more of the following: photovoltaic, solar, wind, hydroelectric, nuclear, geothermal, enhanced geothermal, ocean heat, wave, and tidal. In certain embodiments of the invention, oxyhydrogen microorganisms act as biocatalysts to convert renewable and / or low-carbon emission or carbon-free energy into liquid hydrocarbon fuels or generally high energy density organic compounds, with CO2 captured from flue gas or from the atmosphere or ocean serving as a carbon source. These embodiments of the invention can provide renewable energy technology with the ability to generate transportation fuels with significantly higher energy density than when renewable energy sources are used to generate hydrogen gas, which must be stored in relatively heavy storage systems (e.g., tanks or storage materials) or to charge batteries, which have a relatively low energy density. Additionally, liquid hydrocarbon fuel products according to certain embodiments of the present invention may be more compatible with current transportation infrastructure compared to battery or hydrogen energy storage options.

[0044] The location of one or more process steps that generate an electron donor (e.g., a molecular hydrogen electron donor) in the general process flow of certain embodiments of the present invention is illustrated by Box 3 in FIG. 1 (labeled “Electron Donor Generation”). Electron donors produced in certain embodiments of the present invention using electrochemical and / or thermochemical processes known in the chemical engineering arts and / or electron donors produced from natural sources include, but are not limited to, molecular hydrogen and / or valence or conduction electrons in solid electrode materials and / or other reducing agents including, but not limited to, one or more of the following: ammonia, ammonium, carbon monoxide, dithionites, elemental sulfur, hydrocarbons, metabisulfites, nitric oxide, nitrites, sulfates such as thiosulfates (e.g., but not limited to, sodium thiosulfate (NaSO) or calcium thiosulfate (CaSO)), sulfides such as hydrogen sulfide, sulfites, thionates, thionites, transition metals or their sulfides, oxides, chalcogenides, halides, hydroxides, oxyhydroxides, sulfates, or carbonates in a soluble or solid phase.

[0045] Certain embodiments of the invention use molecular hydrogen as the electron donor. The hydrogen electron donor can be used in a wide variety of applications, including but not limited to the following: electrolysis of water by techniques using proton exchange membranes (PEM), liquid electrolytes such as KOH, high pressure electrolysis, and high temperature electrolysis (HTES) of water vapor; thermochemical decomposition of water via methods including but not limited to the iron oxide cycle, cerium (IV) oxide-cerium (III) oxide cycle, zinc-zinc oxide cycle, sulfur-iodine cycle, copper-chlorine cycle, calcium-bromine-iron cycle, and hybrid sulfur cycle; electrolysis of hydrogen sulfide; thermochemical and / or electrochemical decomposition of hydrogen sulfide; methane reforming with carbon capture and sequestration, coal gasification with carbon capture and sequestration, the Kvaerner process and other processes to produce carbon black products, gasification or pyrolysis of biomass with carbon capture and sequestration, and ferrous iron (Fe2+ ) to ferric iron (Fe 3+ ) or the oxidation of sulfur compounds, where the oxidized forms of iron or sulfur can be recycled back to their reduced state via additional chemical reactions with mineral matter, including, but not limited to, metal sulfides, hydrogen sulfide, or hydrocarbons. + The hydrogen may be produced by methods known in the chemical process industry art, including, but not limited to, one or more of the other electrochemical or thermochemical processes known to produce hydrogen with low or no carbon dioxide emissions, including, but not limited to, half-cell reduction of 1,2-dichloroethane (CO) to H2.

[0046] In certain embodiments of the invention, the hydrogen electron donor is not necessarily produced with low or no carbon dioxide emissions, but hydrogen is produced from waste-to-energy sources or low value energy sources using methods known in the chemical process industry art, including, but not limited to, gasification, pyrolysis, or steam reforming of feedstocks, including, but not limited to, municipal waste, black liquor, agricultural waste, wood waste, stranded natural gas, biogas, sour gas, methane hydrate, tires, sewage, manure, straw, and low value high lignocellulosic biomass in general.

[0047] In certain embodiments of the invention utilizing molecular hydrogen as an electron donor for the carbon fixation reaction performed by the oxyhydrogen microorganism, there is a chemical co-product formed during the production of molecular hydrogen using renewable and / or CO2-free energy input. When water is used as the hydrogen source, oxygen can be a co-product of water splitting via processes including, but not limited to, electrolysis or thermochemical water splitting. In certain embodiments of the invention using water as the hydrogen source, a portion of the oxygen co-product can be used in the oxyhydrogen carbon fixation step for the production of intracellular ATP via the oxyhydrogen reaction enzymatically related to oxidative phosphorylation. In certain embodiments of the invention, oxygen produced by water splitting in excess of that required to maintain favorable (e.g., optimal) conditions for carbon fixation and organic compound production by the oxyhydrogen microorganism can be processed into a form suitable for sale via process steps known in the art of commercial oxygen gas production. In certain embodiments of the invention where hydrogen sulfide is the hydrogen source, sulfur or sulfuric acid can be a chemical co-product of molecular hydrogen production. In certain embodiments of the invention where sulfuric acid is a co-product of hydrogen production, a portion of the sulfuric acid can be used for biomass hydrolysis in a process step following carbon fixation. In certain embodiments of the invention, the excess sulfuric acid and / or sulfur co-produced (e.g., beyond the amount available elsewhere in the carbon recovery and conversion process according to certain embodiments of the invention) can be processed into a form suitable for sale via process steps known in the art of commercial sulfuric acid and / or sulfur production. Process heat can also be generated during the production of hydrogen from hydrogen sulfide. In certain embodiments of the invention, the process heat generated during hydrogen production can be recovered and utilized elsewhere in the carbon recovery and conversion process according to certain embodiments of the invention to improve overall energy efficiency. Chemical and / or thermal and / or electrical co-products can accompany the production of molecular hydrogen for use as an electron donor in certain embodiments of the invention. Chemical and / or thermal and / or electrical co-products of molecular hydrogen production can potentially be used elsewhere in the carbon recovery and conversion process according to certain embodiments of the invention to improve efficiency.In certain embodiments, additional chemical co-products (e.g., beyond the amount available for use in the carbon capture and conversion process according to certain embodiments of the present invention) can be prepared for sale to generate additional revenue streams. Excess heat or electrical energy co-products from the production of molecular hydrogen (e.g., beyond the amount available for use internally in the process) can be delivered for sale for use in other chemical and / or biological processes via means known in the art of heat exchange and transfer, and electricity generation and transmission, including, for example, but not limited to, the conversion of process heat to a saleable form of electricity.

[0048] In certain embodiments of the invention, electrochemical energy stored in solid valence or conduction electrons in electrodes or capacitors or related devices is utilized, alone or in combination with chemical electron donors and / or carriers, to provide reducing equivalents to oxyhydrogen microorganisms for carbon fixation reactions by direct exposure of the electrode material to a microbial culture environment and / or immersion of the electrode material in a microbial culture medium.

[0049] A feature of certain embodiments of the present invention relates to the generation or recycling of electron donors derived from mineral sources (e.g., but not limited to, electron donors derived from minerals containing reduced S and Fe) that can also be used by certain oxyhydrogen microorganisms as a source of reducing equivalents in addition to or instead of hydrogen. Thus, the present invention, in certain embodiments, may enable the use of a largely untapped energy source: inorganic geochemical energy.

[0050] The electron donor used in certain embodiments of the present invention is the following: elemental Fe 0 , siderite (FeCO3), magnetite (Fe3O4), pyrite or marcasite (FeS2), pyrrhotite (Fe (1-x)S (x=0~0.2)), iron pyrite (Fe,Ni)9S8, nickelite (Ni2FeS4), pyrite (Ni,Fe)S2, arsenopyrite (FeAsS), or other iron sulfides, realgar (AsS, pyrite (As2S3), cobaltite (CoAsS), rhodochrosite (MnCO3), chalcopyrite (CuFeS2), bornite (Cu5FeS4), covellite (CuS), tetrahedrite (Cu8Sb2S7), arsenopyrite (Cu3AsS4), arsenite (Cu 12 As 4. S 13 The copper sulfides may be refined from natural mineral sources including, but not limited to, one or more of: copper sulfide (CuS), chalcocite (CuS) or other copper sulfides, sphalerite (ZnS), ferroblende (ZnS) or other zinc sulfides, galena (PbS), benzogite (Pb(Sb,As)S) or other lead sulfides, arginite or goethite (AgS), molybdenite (MoS), goethite (NiS), polydymite (NiS) or other nickel sulfides, stibnite (SbS), GaS, CuSe, cooperite (PtS), laurite (RuS), braggite (Pt,Pd,Ni)S, and FeCl.

[0051] The production of electron donors from natural mineral sources, in certain embodiments of the invention, involves pretreatment steps which may include, but are not limited to, granulating, crushing, or grinding the mineral ore with equipment such as a ball mill to increase the leaching surface area and wetting the mineral ore to create a slurry. In these embodiments of the invention in which the electron donor is produced from a natural mineral source, it may be advantageous if the particle size is controlled so that the sulfides and / or other reductants present in the ore can be concentrated by methods known in the art, including, but not limited to, flotation methods such as dissolved air flotation or foam flotation using floatation towers or mechanical flotation cells, gravity separation, magnetic separation, heavy liquid separation, selective flocculation, water separation, or fractional distillation. After production of the crushed ore or slurry, particulate matter in the leachate or concentrate can be separated by filtration (e.g., vacuum filtration), sedimentation, or other known solid / liquid separation techniques before introducing the electron donor-containing solution into the chemoautotrophic cultivation environment. In addition, any material leached from the mineral ore that is toxic to the chemoautotrophic organisms can be removed prior to exposing the chemoautotrophic organisms to the leachate. Solids remaining after processing of the mineral ore can be concentrated by filter press, disposed of, retained for further processing, or sold, depending on the mineral ore used in the particular embodiment of the invention.

[0052] Electron donors may also be used in certain embodiments of the present invention, including the following: process gas, tail gas, enhanced oil recovery vent gas, biogas, acid mine drainage, landfill leachate, landfill gas, geothermal gas, geothermal sludge or brine, metal contaminants, gangue, tailings, sulfides, disulfides, mercaptans (e.g., but not limited to, methyl mercaptan, dimethyl mercaptan, ethyl mercaptan), carbonyl sulfide, carbon disulfide, alkanesulfonates, dialkyl sulfides, thiosulfates, thiofurans. The sour gas may be purified from contaminants or waste products including, but not limited to, one or more of the following: thiocyanates, isothiocyanates, thioureas, thiols, thiophenols, thioethers, thiophenes, dibenzothiophenes, tetrathionates, dithionites, thionates, dialkyl disulfides, sulfones, sulfoxides, sulfolane, sulfonic acid, dimethylsulfoniopropionate, sulfonate esters, hydrogen sulfide, sulfate esters, organic sulfur, sulfur dioxide, and all other sour gases.

[0053] In addition to mineral sources, electron donors are produced or recycled in certain embodiments of the invention through chemical reactions with hydrocarbons that may be of fossil origin but are used in chemical reactions that produce low or no carbon dioxide gas emissions. These reactions include thermochemical and electrochemical processes. Such chemical reactions used in these embodiments of the invention include, but are not limited to, sulfate reactions or thermochemical reduction of TSR and Muller-Kuhne reactions, methane reforming-like reactions that utilize metal oxides such as, but not limited to, iron oxide, calcium oxide, or magnesium oxide in place of water, where the hydrocarbons react with the hydrogen electron donor product to form solid carbonates with little or no carbon dioxide gas emissions.

[0054] Examples of reactions between metal oxides and hydrocarbons that produce hydrogen electron donor products and carbonates include: 2CH4+Fe2O3+3H2O→2FeCO3+7H2 and / or CH4+CaO+2H2O→CaCO3+4H2 These include, but are not limited to:

[0055] In certain embodiments, the generated electron donor is oxidized in one or more chemical synthesis reaction steps by carbon dioxide, oxygen, and / or an electron acceptor, including, but not limited to, one or more of the following: ferric or other transition metal ions, nitrates, nitrites, sulfates, or valence or conduction band holes in a solid electrode material.

[0056] The location of one or more chemical synthesis steps and / or oxyhydrogen reaction steps in the general process flow of certain embodiments of the present invention is illustrated by Box 4 in FIG. 1, labeled "Bioreactor - Detonating Gas Microorganism."

[0057] At each step in the process where chemosynthesis and / or oxyhydrogen reactions occur, one or more types of electron donors and one or more types of electron acceptors are pumped or otherwise added to the reaction vessel, either as a bolus addition or periodically or continuously to the nutrient medium containing the oxyhydrogen microorganisms. Chemosynthetic reactions, driven by the transfer of electrons from the electron donors to the electron acceptors, can fix inorganic carbon dioxide into organic compounds and biomass.

[0058] In certain embodiments of the present invention, to kinetically promote the chemosynthetic reaction steps, electron carriers can be incorporated into the nutrient medium to facilitate the delivery of reducing equivalents from the electron donor to the oxyhydrogen organism in the presence of electron acceptors and inorganic carbon. This aspect of the present invention can be used to promote the transfer of reduced electrons from poorly soluble electron donors, such as, but not limited to, H2 gas or electrons in solid electrode materials, to the oxyhydrogen organism using electron carriers known in the art of electrical stimulation of microbial metabolism, including, but not limited to, anthraquinone-2,6-disulfonate (AQDS), cobalt sepulchrate, cytochromes, formates, humic substances, iron, methyl viologen, NAD+ / NADH, neutral red (NR), phenazines, and quinones.

[0059] The delivery of reducing equivalents from an electron donor to an oxyhydrogen microorganism for one or more chemosynthetic reactions can, in certain embodiments, be kinetically and / or thermodynamically facilitated through means including, but not limited to, the introduction of a hydrogen storage material into the microbial culture environment that can double as a solid support medium for microbial growth, thereby placing absorbed or adsorbed hydrogen electron donors in close proximity to the hydrogen-oxidizing chemoautotrophic organisms, and / or the direct introduction of an electrode material (e.g., graphite, graphite felt, activated carbon, carbon nanofibers, conductive polymers, steel, iron, copper, titanium, lead, tin, palladium, platinum, platinum-coated titanium, other platinum-coated metals, transition metals, transition metal alloys, transition metal sulfides, oxides, chalcogenides, halides, hydroxides, oxyhydroxides, phosphates, sulfates, and / or carbonates) that can double as a solid support growth medium and a source of electron donors or electron acceptors into the chemoautotrophic culture environment, thereby placing solid-state electrons in close proximity to the microorganisms. Some such embodiments of the present invention may be useful for transferring reducing equivalents from poorly soluble electron donors, such as, but not limited to, H2 gas or electrons in solid electrode materials, to the acid hydrogen microorganisms.

[0060] The culture broth used in the chemical synthesis process according to certain embodiments of the present invention may be an aqueous solution containing suitable minerals, salts, vitamins, cofactors, buffers, and other components required for microbial growth known to those skilled in the art [Bailey and Ollis, Biochemical Engineering Fundamentals, 2nd ed; pp383-384 and 620-622; McGraw-Hill: New York (1986)]. These nutrients can be selected to maximize carbon fixation and promote carbon flow through enzymatic pathways to obtain the desired organic compounds. Selective growth environments such as those used in the art of solid-state or non-aqueous fermentation can be used in certain embodiments. In certain embodiments utilizing aqueous cultures, broths, saltwater, seawater, and / or water from other natural bodies of water, or water from other non-potable sources, acidohydrogen microorganisms can be used if they are tolerant.

[0061] Biochemical pathways can be controlled and optimized for the production of chemical products (e.g., target organic compounds) and / or biomass by maintaining specific growth conditions (e.g., levels of trace micronutrients such as nitrogen, oxygen, phosphorus, sulfur, inorganic ions, and any regulatory molecules, if present, that are not generally considered to be nutrients or energy sources) in certain embodiments of the invention. Depending on the embodiment of the invention, the broth can be maintained in aerobic, microaerobic, anaerobic, anaerobic, or facultative conditions. A facultative environment is considered to be one that has an aerobic upper layer and an anaerobic lower layer due to stratification of the water column.

[0062] Oxygen levels are controlled in certain embodiments of the invention. Oxygen levels can be controlled, for example, to promote the production of target organic compounds by the oxyhydrogen microorganisms via carbon fixation. One purpose of controlling oxygen levels is, in certain embodiments, to control (e.g., optimize) intracellular adenosine triphosphate (ATP) concentrations via cellular reduction of oxygen and production of ATP by oxidative phosphorylation. In some such embodiments, it may be desirable to control ATP concentrations while simultaneously maintaining the environment sufficiently reducing so that the intracellular ratio of NADH (or NADPH) to NAD (or NADP) is relatively high. In some embodiments, ATP levels are increased and / or optimized in the oxyhydrogen microorganisms by means including, but not limited to, one or more of the following: cellular reduction of oxygen and / or other electron acceptors of sufficient oxidative strength for ATP production via oxidative phosphorylation, direct introduction of ATP into the culture medium, and / or direct introduction of a chemical analog of ATP into the culture medium.

[0063] The reduction of oxygen by hydrogen in the oxyhydrogen reaction is generally enzymatically related to the production of ATP via oxidative phosphorylation in oxyhydrogen microorganisms. The oxyhydrogen reaction can act as a substitute for the light reaction of photosynthesis in that it produces both NADPH and ATP. Generally, in oxyhydrogen microorganisms, hydrogenase catalyzes the reduction of NAD to NADH by hydrogen (or alternatively, in some photosynthetic organisms that can perform the oxyhydrogen reaction, hydrogenase catalyzes the reduction of ferredoxin by H2, which in turn reduces NADP to NADPH) [Chen, Gibbs, Plant Physiol. (1992) 100, 1361-1365]. NADH and / or NADPH can then be used as reducing agents in anabolic reactions or to produce ATP by reducing oxygen via oxidative phosphorylation [Bongers, J. Bacteriology, (Oct 1970) 145-151]. Thus, the following light-dependent photosynthetic reactions: 2H2O+2NADP ++2ADP+2Pi+light →2NADPH+2H + +2ATP+O2 Instead of, 1 / 2O2+2NADP + +2ADP+2Pi+3H2→2NADPH+2H + +2ATP+2H2O It is possible to carry out the acid-hydrogen reaction in the dark (i.e., in the virtual absence of visible electromagnetic radiation) and assume that 2 ATP is produced per H consumed, with the hydrogen acting as a substitute for a photon [Bongers, J. Bacteriology, (Oct 1970) 145-151].

[0064] In certain embodiments of the present invention, the goal is to maintain high intracellular concentrations of ATP as well as NADH and / or NADPH to promote carbon fixation and drive anabolic and / or solvent-producing pathways that consume reducing equivalents and also consume ATP and / or reduce the net ATP yield of chemosynthetic carbon fixation. Such biochemical pathways include, but are not limited to, fatty acid synthesis, mevalonate pathway and terpenoid synthesis, butanol pathway and 1-butanol synthesis, acetolactate / α-ketovalerate pathway and 2-butanol synthesis, and ethanol pathway. In some embodiments of the present invention, it is possible to determine a preferred oxygen level. That is, too low an oxygen level may reduce intracellular ATP in oxyhydrogen microorganism below a desired level, while too high an oxygen level may reduce the NADH (or NADPH) to NAD (or NADP) ratio below a desired level.

[0065] In certain embodiments of the invention, the application of oxyhydrogen reactions to generate ATP and NADH and / or NADPH for use in carbon fixation and synthesis of organic compounds may provide advantages over alternative approaches that use anaerobic biochemical pathways for carbon fixation, such as the Wood-Ljungdahl pathway or the methanogenic pathway, which generally produce C1 or C2 organic compounds and it may be difficult to produce compounds above C4 via these pathways.

[0066] The Wood-Ljungdahl pathway can essentially produce acetate, ethanol, butyrate, and butanol, although butyrate and butanol are generally minor products of H2 and CO2 gas fermentation, and chain lengths greater than C4 typically do not occur [Lynd, Zeikus, J. of Bacteriology (1983) 1415-1423; Eichler, Schink, Archives of Microbiology (1984) 140, 147-152]. The acetogenic pathway leading to acetate and butyrate produces net ATP, whereas the solventogenic pathway leading to ethanol and butanol does not [Papoutsakis, Biotechnology & Bioengineering (1984) 26, 174-187; Heise, Muller, Gottschalk, J. of Bacteriology (1989) 5473-5478; Lee, Park, Jang, Nielsen, Kim, Jung, Biotechnology & Bioengineering (2008) 101, 2, 209-228]. Since ATP is required for cell maintenance, there will generally be a certain amount of relatively undesirable non-biofuel co-products (i.e., organic acids) from acetogenic bacteria that fix carbon via the Wood-Ljungdahl pathway, and reducing equivalents and carbon will be wasted.

[0067] The production of hydrocarbons with chain lengths longer than C4 is most commonly achieved biologically through fatty acid biosynthesis [Fischer, Klein-Marcuschamer, Stephanolpoulos, Metabolic Engineering (2008) 10, 295-304]. Unlike the solvent-producing pathways derived from the Wood-Ljungdahl pathway, fatty acid synthesis involves a net consumption of ATP. For example, the net reaction for the synthesis of palmitic acid (C16), starting in this example from acetyl-CoA, is given as follows: 8 Acetyl-CoA + 7 ATP + H2O + 14 NADPH + 14 H + → Palmitic acid + 8 CoA + 14 NADP + +7ADP+7Pi

[0068] One of the challenges in using anaerobic pathways such as methanogenesis or Wood-Ljungdahl for ATP generation to drive fatty acid synthesis is the relatively low amount of ATP produced per H2 consumed, with only 1 ATP per 4 H2 for methane [Thauer, RK, Kaster, AK, Seedorf, H., Buckel, W. & Hedderich, R Methanogenic archaea: ecologically relevant differences in energy conservation. Nat Rev Microbiol 6, 579-591, doi:nrmicro1931[pii]] or acetate production, and 1 ATP per 10 H2 for butyrate production [Papoutsakis, Biotechnology & Bioengineering (1984) 26, 174-187; Heise, Muller, Gottschalk, J. of Bacteriology (1989) 5473-5478; Lee, Park, Jang, Nielsen, Kim, Jung, Biotechnology & Bioengineering (2008) 101, 2, 209-228]. In contrast, in the oxyhydrogen reaction, hydrogen-utilizing oxyhydrogen microorganisms can generate up to 2 ATP per H2 consumed [Bongers, J. Bacteriology, (Oct 1970) 145-151]. In other words, oxyhydrogen microorganisms can generate up to 8 times more ATP per H2 consumed than methanogenic or acetogenic microorganisms. Furthermore, the pathway of ATP production via the oxyhydrogen reaction produces water that can be easily incorporated into the process stream, rather than the relatively undesirable acetate or butyrate products of acidogenesis, which can disrupt the pH of the system and rise to concentrations toxic to organisms.

[0069] The highest energy density fuel that can actually be naturally achieved via the Wood-Ljungdahl pathway with inorganic carbon input is typically ethanol at 30 MJ / kg, but butanol at 36.1 MJ / kg is also possible. The production of diesel fuel (46.2 MJ / kg) or JP-8 aviation fuel (43.15 MJ / kg) can typically be difficult and generally less efficient when utilizing anaerobic pathways such as Wood-Ljungdahl, due to the increased amount of H2 that needs to be consumed in the obligate anaerobic pathway per ATP generated that is required for fatty acid synthesis. However, these high-density infrastructure-compatible liquid fuels can be readily produced via fat synthesis pathways driven by ATP, NADH, or NADPH generated by the oxyhydrogen reaction.

[0070] The lipid content of the biomass and the efficiency of the lipid biosynthesis pathway are two factors that can affect the overall efficiency of certain embodiments of the present invention in converting CO2 and other C1 compounds to long-chain compounds (e.g., infrastructure-compatible fuels). The lipid content of the biomass can determine the proportion of carbon and reducing equivalents that direct the synthesis of fuel products, as opposed to other components of the biomass. The lipid content can determine the amount of energy input from the reducing equivalents that can be recovered in the final fuel product. Similarly, the efficiency of the metabolic pathway can determine the amount of reducing equivalents that must be consumed in converting CO2 and hydrogen to lipids along the lipid biosynthesis pathway. Many oxyhydrogen microorganisms include species that are high in lipid content and contain efficient pathways from H2 and CO2 to lipids. In certain embodiments of the present invention, high lipid content species such as, but not limited to, Rhodococcus opacus, which may have a lipid content of more than 70% [Gouda, MK, Omar, SH, Chekroud, ZA & Nour Eldin, HMBioremediation of kerosene I: A case study in liquid media. Chemosphere 69, 1807-1814, doi:S0045- 6535(07)00738-2; Waltermann, M., Luftmann, H., Baumeister, D., Kalscheuer, R. & Steinbuchel, A. Rhodococcus opacus strain PD630 as a new source of high-value single-cell oil? Isolation and characterization of triacylglycerols and other storage lipids. Microbiology 146(Pt 5), 1143-1149(2000).] and / or species that utilize highly efficient metabolic pathways such as (but not limited to) the reverse tricarboxylic acid cycle [i.e., the reverse citric acid cycle] for carbon fixation [Miura, A., Kameya, M., Arai, H., Ishii, M. & Igarashi, Y.A soluble NADH-dependent fumarate reductase in the reductive tricarboxylic acid cycle of Hydrogenobacter thermophilus TK-6. J Bacteriol 190, 7170-7177, doi:JB.00747-08[pii]10.1128 / JB.00747-08(2008)., Shively, JM, van Keulen, G. & Meijer, WG Something from almost nothing: carbon dioxide fixation in chemoautotrophs. Annu Rev Microbiol 52, 191-230, doi:10.1146 / annurev.micro.52.1.191(1998).] is used. In terms of energy efficiency, the reverse tricarboxylic acid pathway may be a relatively advantageous pathway. Palmitate synthesis from H2 and CO2 is generally about 15% more efficient in terms of reducing equivalents consumed than palmitate synthesis in acetogens, because acidohydrogen microorganisms produce increased ATP per reducing equivalent consumed in the acidohydrogen reaction.

[0071] Inorganic carbon sources used in the chemical synthesis reaction process steps according to certain embodiments of the invention include, but are not limited to, one or more of the following: carbon dioxide-containing gas streams, which may be pure or mixtures; liquefied CO2; dry ice; carbon dioxide dissolved in solutions, including aqueous solutions such as seawater; carbonate or bicarbonate ions; inorganic carbon in solid forms, such as carbonate or bicarbonate minerals. Carbon dioxide and / or other forms of inorganic carbon can be introduced to the process steps where carbon fixation occurs, either as a bolus addition, periodically, or continuously to a nutrient medium contained in a reaction vessel. Organic compounds containing only one carbon atom that can be used in the synthesis reaction process steps according to certain embodiments of the invention include, but are not limited to, one or more of the following: carbon monoxide, methane, methanol, formate, formic acid, and / or mixtures containing C1 chemicals, including, but not limited to, various syngas compositions produced from various fixed carbon feedstocks that have been gasified or steam reformed.

[0072] In certain embodiments, organic compounds and / or electron donors containing only one carbon atom are produced via gasification and / or pyrolysis of biomass and / or other organic matter (e.g., biomass and / or other organic matter from waste or low-value sources) and provided as syngas to a culture of oxyhydrogen microorganisms. In this case, the ratio of hydrogen to carbon monoxide in the syngas may or may not be adjusted via a means such as a water-gas shift reaction before the syngas is delivered to the microbial culture. In certain embodiments, organic compounds and / or electron donors containing only one carbon atom are produced via methane steam reforming from methane or natural gas (e.g., stranded natural gas or natural gas otherwise combusted or released to the atmosphere) or biogas or landfill gas and provided as syngas to a culture of oxyhydrogen microorganisms. In this case, the ratio of hydrogen to carbon monoxide in the syngas may or may not be adjusted via a means such as a water-gas shift reaction before the syngas is delivered to the microbial culture.

[0073] In certain embodiments of the invention, carbon dioxide-containing flue gas is collected from the chimney at temperatures, pressures, and gas compositions characteristic of raw exhaust and directed, with minimal modification, into the reactor where carbon fixation occurs. In some embodiments where impurities harmful to chemoautotrophic organisms are not present in the flue gas, modification of the flue gas upon entering the reactor can be limited to compression required to pump the gas into the reactor system and / or heat exchange required to reduce the gas temperature to a temperature suitable for the microorganisms.

[0074] Oxyhydrogen microorganisms generally have advantages over strictly anaerobic acetogens or methanogens in carbon capture applications due to the higher oxygen tolerance of the oxyhydrogen microorganisms. Since industrial flue gas is one of the contemplated CO2 sources for certain embodiments of the present invention, the relatively higher oxygen tolerance of the oxyhydrogen microorganisms compared to the obligately anaerobic methanogens or acetogens allows them to tolerate the 2-6% O2 content found in typical flue gas.

[0075] In some embodiments where carbon dioxide-containing flue gas is transported into the system to dissolve the carbon dioxide into solution (e.g., as is well known in the carbon capture art), the scrubbed flue gas (which typically contains primarily inert gases such as nitrogen) can be released into the atmosphere.

[0076] The gas that is dissolved in solution and fed to the culture broth or dissolved directly in the culture broth in certain embodiments of the invention includes a gaseous electron donor (e.g., hydrogen gas) in addition to carbon dioxide, but may include other electron donors such as, but not limited to, carbon monoxide and other components of syngas, hydrogen sulfide, and / or other sour gases in certain embodiments of the invention. It is also possible to maintain a controlled amount of oxygen in the culture broth according to some embodiments of the invention, and in certain embodiments, the oxygen will be effectively dissolved in the solution fed to the culture broth and / or will be dissolved directly in the culture broth.

[0077] Dissolution of oxygen, carbon dioxide, and / or electron donor gases (e.g., but not limited to, hydrogen and / or carbon monoxide) can be accomplished in some embodiments of the invention using compressor, flow meter, and / or flow valve mechanisms known to those skilled in the art of bioreactor-scale microbial cultivation and can be fed into one or more of the following mechanisms commonly used to pump gases into solution: sparging devices, diffusers (e.g., but not limited to, dome-shaped, tube-shaped, disk-shaped, or doughnut-shaped geometries), coarse or fine bubble aerators, and / or Venturi devices (but not limited to). In certain embodiments of the invention, surface aeration can also be achieved using paddle aerators and the like. In certain embodiments of the invention, mechanical mixing is used with impellers and / or turbines to enhance gas dissolution. In some embodiments, a hydraulic shear device can be used to reduce bubble size.

[0078] In certain embodiments of the invention where air or oxygen needs to be effectively pumped into the culture broth to maintain favorable (e.g., optimal) oxygen loading levels, oxygen bubbles are injected into the broth at a desired (e.g., optimal) diameter for mixing and oxygen transfer. This has been found to be 2 mm in certain embodiments [Environment Research Journal May / June 1999 pgs.307-315]. In certain aerobic embodiments of the invention, a process of shearing the oxygen bubbles is used to achieve this bubble diameter, as described in U.S. Pat. No. 7,332,077. In some embodiments, the bubbles have an average diameter of 7.5 mm or less, and slugging is avoided.

[0079] In certain embodiments of the invention utilizing hydrogen as the electron donor, hydrogen gas is supplied to the chemoautotrophic culture vessel by bubbling it into the culture medium and / or by diffusing it through a membrane that contacts and is impermeable to the culture medium. The latter method is considered safer in many embodiments and may be preferred, since hydrogen accumulating in the gas phase can create explosive conditions (explosive hydrogen concentrations in air range from 4-74.5%, which are avoidable in certain embodiments of the invention). In some embodiments, the membrane is coated with a biofilm of oxyhydrogen microorganisms, so that hydrogen must diffuse into the microorganisms after passing through the membrane.

[0080] Additional chemicals known in the art necessary or useful for the maintenance and growth of acid-hydrogen microorganisms can be added to the culture broth according to certain embodiments of the present invention. These chemicals may include nitrogen sources such as ammonia, ammonium (e.g., ammonium chloride (NH4Cl), ammonium sulfate ((NH4)2SO4)), nitrates (e.g., potassium nitrate (KNO3)), urea, or organic nitrogen sources, phosphates (e.g., disodium phosphate (Na2HPO4), potassium phosphate (KH2PO4), phosphoric acid (H3PO4), potassium dithiophosphate (K3PS2O2), potassium orthophosphate (K3PO4), dipotassium phosphate (K2HPO4)), sulfates, yeast extract, chelated iron, potassium (e.g., potassium phosphate (KH2PO4), potassium nitrate (KNO3), potassium iodide (KI), potassium bromide (KBr)), and other inorganic salts, minerals, and micronutrients (e.g., sodium chloride (NaCl), magnesium sulfate (MgSO47H2O) or magnesium chloride (MgCl2), calcium chloride (CaCl2) or calcium carbonate (CaCO3), manganese sulfate, potassium phosphate (KH2PO4), potassium nitrate (KNO3), potassium iodide (KI), potassium bromide (KBr)). (MnSO47H2O) or manganese chloride (MnCl2), ferric chloride (FeCl3), ferrous sulfate (FeSO47H2O) or ferrous chloride (FeCl24H2O), sodium bicarbonate (NaHCO3) or sodium carbonate (Na2CO3), zinc sulfate (ZnSO4) or zinc chloride (ZnCl2), ammonium molybdate (NH4MoO4) or sodium molybdate (Na2MoO42H2O), cuprous sulfate (CuSO4) or copper chloride (CuCl 22H2O), cobalt chloride (CoCl26H2O), aluminum chloride (AlCl3.6H2O), lithium chloride (LiCl), boric acid (H3BO3), nickel chloride (NiCl26H2O), tin chloride (SnCl2H2O), barium chloride (BaCl22H2O), copper selenate (CuSeO45H2O) or sodium selenite (Na2SeO3), sodium metavanadate (NaVO3), chromium salts).In certain embodiments, mineral salts medium (MSM) as formulated by Schlegel et al. may be used [Thermophilic bacteria, Jakob Kristjansson, Chapter 5, Section III, CRC Press, (1992)].

[0081] In certain embodiments, the concentrations of nutritional chemicals (e.g., electron donors and electron acceptors) are maintained at levels that favor enhanced (e.g., maximal) carbon uptake and fixation and / or production of organic compounds (e.g., as close as possible to their respective optimal levels), which will vary depending on the oxyhydrogen species utilized, but which are known or can be determined without undue experimentation by one of ordinary skill in the art of oxyhydrogen microbial cultivation.

[0082] In certain embodiments of the invention, nutrient levels are controlled along with waste product levels, pH, temperature, salinity, dissolved oxygen and carbon dioxide, gas and liquid flow rates, agitation speed, and pressure in the microbial culture environment. Operating parameters that affect carbon fixation can be monitored using sensors (e.g., using dissolved oxygen and / or redox probes to measure the concentration of electron donors / electron acceptors) and controlled manually or automatically based on feedback from the sensors by using devices including, but not limited to, actuated valves, pumps, and agitators. The temperature of the inlet broth as well as the inlet gas can be adjusted by means such as, but not limited to, heat exchangers.

[0083] Dissolution of gases and nutrients required to sustain the oxyhydrogen culture and promote carbon fixation, as well as removal of inhibitory waste products, can be facilitated by agitation of the culture broth. Oxyhydrogen microorganisms are capable of carrying out carbon fixation reactions throughout the volume of the reactor, providing an advantage over other approaches, including those that utilize photosynthetic organisms (which are limited to surface area because photosynthesis requires light). The use of agitation can further increase this advantage by distributing the microorganisms, nutrients, optimal growth environment, and / or CO2 as widely and uniformly as possible throughout the reactor volume to promote production (e.g., maximizing the reactor volume in which the carbon fixation reaction will occur at an optimal rate).

[0084] Agitation of the culture broth in certain embodiments of the invention can be accomplished by recirculation of the broth from the bottom to the top of the vessel through a recirculation conduit, sparging with carbon dioxide, an electron donor gas (e.g., H), oxygen, and / or air, and / or by devices including, but not limited to, mechanical mixers such as, but not limited to, impellers (100-1000 rpm) and turbines.

[0085] In certain embodiments of the invention, the chemical environment, oxyhydrogen microorganisms, electron donors, electron acceptors, oxygen, pH, and / or temperature levels are varied, either spatially and / or temporally, across a series of fluidly connected bioreactors such that a wide variety of carbon fixation reactions and / or biochemical pathways leading to organic compounds are carried out in sequential or parallel fashion.

[0086] The nutrient medium containing the oxyhydrogen microorganisms can, in certain embodiments of the invention, be partially or completely removed from the bioreactor periodically or continuously and replaced with fresh cell-free medium, e.g., to maintain the cell culture in exponential growth phase, to maintain the cell culture in growth phase (exponential or stationary) with an increased (e.g., optimal) carbon fixation rate, to replenish depleted nutrients in the growth medium, and / or to remove inhibitory waste products.

[0087] The high growth rates achievable by oxyhydrogen species can match or exceed the maximum rates of carbon fixation and / or biomass production per unit of biomass left achievable by photosynthetic microorganisms. As a result, in certain embodiments, excess biomass can be produced. Excessive growth of cell mass can be removed from the system to produce biomass products. In some embodiments, excess growth of cell mass can be removed from the system to maintain a desired (e.g., optimal) microbial population and cell density in the microbial culture to achieve a continuous high carbon recovery fixation rate.

[0088] Another advantage of certain embodiments of the present invention relates to the vessels used to contain the carbon fixation reaction environment and to carry out the cultivation in the carbon capture and fixation process. Exemplary cultivation vessels that can be used in some embodiments of the present invention to cultivate and grow oxyhydrogen microorganisms for carbon dioxide capture and fixation include those known to those skilled in the art of large-scale microbial cultivation. Such vessels, which may be of natural or artificial origin, include, but are not limited to, airlift reactors, biological scrubber columns, bioreactors, bubble columns, caverns, caves, cisterns, continuous stirred tank reactors, countercurrent upward expansion bed reactors, digesters, particularly digester systems known in the prior art of sewage and wastewater treatment or bioremediation, filters, such as, but not limited to, trickle filters, rotating biological contactor filters, rotating disks, soil filters, fluidized bed reactors, gas lift fermenters, immobilized cell reactors, lagoons, membrane biofilm reactors, microbial fuel cells, ore shafts, pachuca tanks, packed bed reactors, plug flow reactors, ponds, pools, quarries, storage tanks, static mixers, tanks, towers, trickle bed reactors, vats, vertical shaft bioreactors, and wells. The vessel bottom, siding, walls, lining, and / or top can be constructed from one or more materials including, but not limited to, bitumen, cement, ceramics, clay, concrete, epoxy, fiberglass, glass, macadam, plastic, sand, sealant, soil, steel or other metals and their alloys, stone, tar, wood, and any combination thereof. In certain embodiments of the invention where the oxyhydrogen microorganisms require a corrosive growth environment and / or produce corrosive chemicals via carbon fixation reactions, a corrosion resistant material can be used to line the interior of the vessel that contacts the growth medium.

[0089] Because oxyhydrogen microbes do not require sunlight to fix CO2, they can be used in carbon capture and fixation processes that avoid many of the drawbacks that can accompany photosynthesis-based carbon capture and conversion technologies. For example, shallow, large ponds are not required to support chemical synthesis, nor are bioreactors with high surface area to volume ratios and special features or transparent materials, such as solar collectors. Technologies such as certain embodiments of the invention using oxyhydrogen microbes are not subject to the diurnal, geographic, meteorological, and seasonal constraints that are typically associated with photosynthesis-based systems.

[0090] In certain embodiments of the invention, material costs are minimized by using chemical synthesis vessel geometries with low surface area to volume ratios, such as, but not limited to, cubic, medium aspect ratio cylindrical, ellipsoidal or "ovoid", hemispherical or spherical geometries, unless other design considerations (e.g., land footprint) override material costs. The ability to use small reactor geometries can be attributed to the absence of light requirements for chemical synthesis reactions, in contrast to photosynthetic techniques, which require large surface area to volume ratios to provide sufficient light exposure.

[0091] Also, the lack of light dependency of oxyhydrogen microorganisms allows for plant designs with a much smaller footprint than those traditionally associated with photosynthetic approaches. For example, where land availability constraints necessitate a need to minimize plant footprints, long vertical shaft bioreactor systems can be used for chemosynthetic carbon capture. Long vertical shaft bioreactors are described, for example, in U.S. Pat. Nos. 4,279,754, 5,645,726, 5,650,070, and 7,332,077.

[0092] Unless other requirements prevail, in certain embodiments of the invention, the introduction of erosive matter into the vessel surface and / or reactor that causes high losses of water, nutrients, and / or heat is minimized. Such surfaces can be minimized due to the absence of light requirements for chemical synthesis. Surfaces that cause high losses of water, nutrients, and / or heat and are lost through erosion are generally the same surfaces that transmit the light energy required for photosynthesis, so such surfaces cannot generally be minimized in photosynthesis-based technologies.

[0093] Fermentors of the present invention may, in some embodiments, utilize reactor designs known to those skilled in the art of large-scale microbial cultivation to maintain aerobic, microaerobic, anaerobic, anaerobic, or facultative environments depending on the embodiment of the invention. For example, similar to the design of many wastewater treatment plants, in certain embodiments of the present invention, tanks are arranged in serial forward fluid communication one after the other, with certain tanks maintained under aerobic conditions and others maintained under anaerobic conditions, to perform multiple chemosynthetic, and in certain embodiments, heterotrophic, process steps on a carbon dioxide waste stream.

[0094] In a particular embodiment of the present invention, the oxyhydrogen microorganism is immobilized in its growth environment. The immobilization of the microorganism can be achieved using any medium known in the art of microbial culture that supports colonization by the microorganism, for example, but not limited to, a medium that allows the microorganism to grow on a matrix, mesh, or membrane made from any of a wide range of natural and synthetic materials and polymers, including, but not limited to, one or more of the following: glass wool, clay, concrete, wood fiber, inorganic oxides (e.g., ZrO2, Sb2O3, or Al2O3), organic polymer polysulfone, or open-pore polyurethane foam with high specific surface area. Additionally, the microorganisms in certain embodiments of the present invention may be grown on the surfaces of unbound objects distributed throughout the growth vessel as known in the art of microbial culture, including, but not limited to, one or more of the following objects, including, but not limited to, beads, sand, silicates, meerschaum, glass, ceramics, small diameter plastic disks, spheres, tubes, particles, or other shapes known in the art, shredded coconut husks, ground corn cobs, activated charcoal, granular coal, crushed coral, sponge balls, suspension media, small pieces of small diameter elastomeric polyethylene tubing, porous fabric, Berl saddles, and hanging strings from Raschig rings. Materials used in microbial support media may include hydrogen storage materials and / or electrode materials to increase the transfer of reducing equivalents to the oxyhydrogen microorganisms. Electrode materials that can be used include, but are not limited to, one or more of the following: graphite, activated carbon, carbon nanofibers, conductive polymers, steel, iron, copper, titanium, lead, tin, palladium, platinum, transition metals, transition metal alloys, transition metal sulfides, oxides, chalcogenides, halides, hydroxides, oxyhydroxides, phosphates, sulfates, or carbonates.Hydrogen storage materials that can be used in this application include, but are not limited to, titanium, graphite, activated carbon, carbon nanofibers, iron, copper, lead, tin, metal hydrides (e.g., including but not limited to, TiFeH2, TiH2, VH2, ZrH2, NiH, NbH2, PdH), polymers known in the art for hydrogen storage (e.g., including but not limited to, metal organic frameworks (MOFs)), and nanoporous polymeric materials. In certain embodiments, the hydrogen storage material does not react strongly with water and does not strongly or rapidly affect the pH of the culture medium.

[0095] Inoculation of the oxyhydrogen culture into the fermenter can be accomplished by methods including, but not limited to, transferring the culture from an existing oxyhydrogen culture residing in another carbon capture fixation system according to certain embodiments of the present invention and / or transferring the culture from an incubation of a seed stock that occurs in an incubator. The seed stock of the oxyhydrogen strain can be transported and stored in a form including, but not limited to, powder, liquid, frozen or lyophilized form, or any other suitable form that would be readily apparent to one of skill in the art. In certain embodiments where the culture is established in a very large reactor, the culture can be grown and established in successively larger intermediate scale vessels prior to inoculation of the phenyl scale tank.

[0096] The location of one or more process steps that separate cell mass from a process stream in the general process flow of certain embodiments of the present invention is illustrated by Box 5 in FIG. 1, labeled "Cell Separation."

[0097] Separation of the cell clumps from the liquid suspension can be accomplished by methods known in the art of microbial culture, including, but not limited to, one or more of the following: centrifugation, flocculation, floatation, filtration using membrane, hollow fiber, spiral wound, or ceramic filter systems, vacuum filtration, tangential flow filtration, clarification, sedimentation, or hydrocyclone. (Examples of cell clump harvesting techniques are provided in WO 08 / 00558, published Jan. 8, 1998; U.S. Pat. Nos. 5,807,722, 5,593,886, and 5,821,111.) In certain embodiments where the cell clumps are fixed onto a matrix, they can be harvested by methods including, but not limited to, gravity settling or filtration, and separated from the growth substrate by liquid shear forces.

[0098] In certain embodiments of the invention, when excess cell mass is removed from the culture, it can be combined with fresh broth so that sufficient biomass is retained for one or more chemosynthetic reaction steps and recycled back into the cell culture as shown by the process arrow marked "Recycled Cell Mass" in FIG. 1. This allows for continued enhanced (e.g., optimal) autotrophic carbon fixation production of organic compounds. The cell mass collected by the harvesting system can be recycled back to the fermenter, for example, using an airlift pump or an intermittent pump. In certain embodiments, the cell mass recycled back to the fermenter is not exposed to a flocculant unless the flocculant is non-toxic to the microorganism.

[0099] In certain embodiments of the invention, the microbial culture and carbon fixation reaction are maintained at steady state with cell population and environmental parameters (e.g., cell density, chemical concentrations) targeted at constant (e.g., optimal) levels over time using continuous inflow removal of nutrient medium and / or biomass. Cell density can be monitored in certain embodiments of the invention by direct sampling, by correlation of optical density with cell density, and / or by particle size analyzer. Hydraulic retention time and biomass retention time can be separated to allow independent control of both broth chemistry and cell density. The hydraulic retention time can be relatively short compared to the biomass retention time, and the dilution rate can be kept high enough to allow for high replenishment of broth for cell growth. The dilution rate is set to an optimal tradeoff between replenishment of culture broth and increased process costs from pumping, increased inputs, and other requirements that come with the dilution rate.

[0100] To aid in the processing of the biomass products into biofuels or other useful products, after the cell recycling step, the excess microbial cells in certain embodiments of the invention can be disrupted using methods including, but not limited to, ball milling, cavitation pressure, ultrasonic treatment, or mechanical shear.

[0101] In some embodiments, harvested biomass can be dried in one or more process steps in Box 7, labeled "Dryer" in the general process flow of certain embodiments of the invention illustrated in FIG.

[0102] In certain embodiments of the invention, drying of the excess biomass can be accomplished using techniques including, but not limited to, centrifugation, drum drying, evaporation, freeze drying, heating, spray drying, vacuum drying, and / or vacuum filtration. Waste heat from industrial sources of flue gas can be used in certain embodiments to dry the biomass. In addition, chemical synthesis oxidation of electron donors is typically exothermic and typically produces waste heat. In certain embodiments of the invention, the waste heat can be used to dry the biomass.

[0103] In certain embodiments of the invention, the biomass is further processed after drying to aid in the production of biofuels or other useful chemicals by separating lipid contents or other target biochemicals from the microbial biomass. Lipid separation can be performed using non-polar solvents that extract lipids, such as, but not limited to, hexane, cyclohexane, ethyl ether, alcohols (such as isopropanol, ethanol), tributyl phosphate, supercritical carbon dioxide, trioctylphosphine oxide, secondary and tertiary amines, or propane. Other useful biochemicals can be extracted using solvents including, but not limited to, chloroform, acetone, ethyl acetate, and tetrachloroethylene.

[0104] The extracted lipid content of the biomass can be processed using methods known in the science and art of biomass refining, including, but not limited to, one or more of the following: catalytic cracking and reforming, decarboxylation, hydrotreating, isomerization, to produce petroleum and petrochemical substitutes, including, but not limited to, JP-8 jet fuel, diesel, gasoline, and one or more of other alkanes, olefins, and aromatics. In some embodiments, the extracted lipid content of the biomass can be converted to ester-based fuels such as biodiesel (fatty acid methyl esters or fatty acid ethyl esters) via processes known in the science and art of biomass refining, including, but not limited to, transesterification and esterification.

[0105] The broth remaining after removal of the cell mass can be pumped into a system for removal of chemical products of the chemical synthesis and / or spent nutrients which can be recycled or recovered and / or disposed of.

[0106] The location of one or more process steps for recovering chemicals from a process stream in the general process flow of certain embodiments of the present invention is illustrated in FIG. 1 by Box 8, labeled "Separation of Chemical Co-Products."

[0107] Recovery and / or recycling of chemical synthesis chemical products and / or spent nutrients from the aqueous broth solution can be achieved in certain embodiments of the present invention using equipment and techniques known in the art of process industry and targeted to obtain the chemical products of certain embodiments of the present invention, for example, but not limited to, solvent extraction, aqueous extraction, distillation, fractional distillation, cementation, chemical precipitation, alkaline solution absorption, absorption or adsorption on activated carbon, ion exchange resins, or molecular sieves, modification of solution pH and / or redox potential, evaporators, fractional crystallizers, solid / liquid separators, nanofiltration, and all combinations thereof.

[0108] In certain embodiments of the invention, long chain organic compounds suitable for refining into biofuel products produced via free fatty acids, lipids, or other media, or chemical synthesis, can be recovered from the process stream in the step of Box 8 of FIG. 1. These free organic molecules can be released from the oxyhydrogen microorganism into the process stream solution via means including, but not limited to, cell excretion or secretion or cell lysis. In certain embodiments of the invention, the recovered organic compounds are processed using methods known in the science and art of biomass refining, including, but not limited to, one or more of the following: catalytic cracking and reforming, decarboxylation, hydrotreating, isomerization. Such processes can be used to produce petroleum and petrochemical substitutes, including, but not limited to, one or more of the following: JP-8 jet fuel, diesel, gasoline, and other alkanes, olefins, and aromatics. The recovered fatty acids can be converted into ester-based fuels such as biodiesel (fatty acid methyl esters or fatty acid ethyl esters) via processes known in the science and art of biomass refining, including, but not limited to, transesterification and esterification.

[0109] In some embodiments, after recovery of chemicals from the process stream, removal of waste products occurs as shown by box 9 marked "Waste Removal" in Figure 1. The residual broth can be returned to the culture vessel along with replacement water and / or replacement nutrients.

[0110] In certain embodiments of the invention involving the chemoautotrophic oxidation of electron donors extracted from mineral ores, a solution of oxidized metal cations may remain after the chemosynthesis reaction step. Also, solutions rich in dissolved metal cations may result from the input of dirty flue gases into the process, particularly from coal burning plants. In some such embodiments of the invention, metal cations may be stripped from the process stream by methods including, but not limited to, cementation of scrap iron, steel wool, copper, or zinc dust, chemical precipitation as sulphide or hydroxide precipitation, electrowinning to plate out certain metals, absorption onto activated carbon or ion exchange resins, modification of solution pH and / or redox potential, and solvent extraction. In certain embodiments of the invention, the recovered metals may be sold for additional revenue streams.

[0111] In certain embodiments, the chemicals used in the processes for chemical product recovery, nutrient and water recycling, and waste removal have low toxicity to humans and low toxicity to the oxyhydrogen microorganisms used when exposed to the process streams that are recycled back into the growth vessel.

[0112] In certain embodiments of the present invention, the pH of the microbial culture is controlled. To address the drop in pH, a neutralization step can be performed to maintain the pH within an optimal range for the maintenance and growth of the microorganisms before recycling the broth back into the culture tank. Neutralization of the acid in the broth can be achieved by adding a base, including but not limited to limestone, lime, sodium hydroxide, ammonia, caustic potash, magnesium oxide, and iron oxide. In certain embodiments, the base is generated from a carbon dioxide-free source such as naturally occurring basic minerals, including but not limited to calcium oxide, magnesium oxide, iron oxide, iron ore, metal oxide-containing olivine, metal oxide-containing serpentine, metal oxide-containing ultrabasic deposits, and underground basic saline aquifers. When limestone is used for neutralization, carbon dioxide will generally be released. This carbon dioxide can be directed back into the growth vessel for uptake by chemical synthesis and / or sequestered in some other way rather than being released into the atmosphere.

[0113] A further feature of certain embodiments of the present invention relates to uses of organic compounds and / or biomass produced via one or more chemical synthesis process steps according to certain embodiments of the present invention. Uses of the produced organic compounds and / or biomass include the production of liquid fuels including, but not limited to, JP-8 jet fuel, diesel, gasoline, octane, biodiesel, butanol, ethanol, propanol, isopropanol, propane, alkanes, olefins, aromatics, fatty alcohols, fatty acid esters, alcohols, 1,3-propanediol, 1,3-butadiene, 1,4-Butanediol, 3-Hydroxypropionate, 7-ADCA / Cephalosporin, ε-Caprolactone, γ-Valerolactone, Acrylates, Acrylic Acid, Adipic Acid, Ascorbate, Aspartate, Ascorbic Acid, Aspartic Acid, Caprolactam, Carotenoids, Citrate, Citric Acid, DHA, Docetaxel, Erythromycin, Ethylene, Gamma Butyrolactone, Glutamate, Glutamic Acid, HPA, Hydroxybutyrate, Isopentenol, Isoprene, Isoprenoids, Itaconate, Itaconic Acid, Lactate, Lactic Acid, Lanosterol, Levulinic Acid, Lycopene, Lysine, Malate, Malonic Acid, Peptides, ω-3DHA, ω Fatty Acids, Paclitaxel, PHA , PHB, polyketides, polyols, propylene, pyrrolidones, serine, sorbitol, statins, steroids, succinates, terephthalates, terpenes, THF, rubbers, wax esters, polymers, commodity chemicals, industrial chemicals, specialty chemicals, paraffin substitutes, additives, nutritional supplements, nutraceuticals, pharmaceuticals, pharmaceutical intermediates, personal care products; as raw materials and / or feedstocks for organic chemical production, manufacturing processes or chemical processes, including, but not limited to, alcohol fermentation or other biofuel fermentation and / or gasification and liquefaction processes and / or other biofuel production processes (e.g., catalytic cracking, direct liquefaction, Fisher Scientific); as a feedstock for processes such as, but not limited to, the Tropsch process, hydrogenation, methanol synthesis, pyrolysis, transesterification, or microbial syngas conversion; as a biomass fuel for combustion, particularly as a fuel to be co-combusted with fossil fuels; as a source of pharmaceutical, medicinal, or nutritional substances, such as commercial enzymes, antibiotics, amino acids, vitamins, bioplastics, glycerol, or 1,Uses include, but are not limited to, as a carbon source for large-scale fermentation to produce a variety of chemicals, including, but not limited to, 3-propanediol; as a nutrient source for the growth of other microorganisms or organisms; as feed for animals, including, but not limited to, cattle, sheep, chickens, pigs, or fish; as a feedstock for the production of methane or biogas; as a fertilizer, soil additive, and soil stabilizer.

[0114] A further feature of certain embodiments of the present invention relates to the optimization of oxyhydrogen microorganisms for carbon dioxide capture, carbon fixation to organic compounds, and production of other valuable chemical co-products. This optimization can be performed through methods known in the art of accelerated mutagenesis (e.g., using ultraviolet light or chemical treatments), genetic engineering or genetic modification, hybridization, synthetic biology, or artificial breeding, including, but not limited to, traditional selective breeding. In certain embodiments of the present invention that utilize a consortium of microorganisms, the community can be enriched with the desired oxyhydrogen microorganisms using methods known in the art of microbiology through growth in the presence of targeted electron donors, including, but not limited to, hydrogen, acceptors, including, but not limited to, oxygen, and environmental conditions.

[0115] A further feature of certain embodiments of the present invention relates to the modification of the biochemical pathways of oxyhydrogen microorganisms to produce target organic compounds. This modification can be achieved by manipulating the growth environment and / or through methods known in the art of accelerated mutagenesis (e.g., using ultraviolet light treatment or chemical treatment), genetic engineering or genetic modification, hybridization, synthetic biology, or artificial breeding, including, but not limited to, traditional selective breeding. Organic compounds produced through modification include, but are not limited to, one or more of the following: biofuels, including, but not limited to, JP-8 jet fuel, diesel, gasoline, biodiesel, butanol, ethanol, long chain hydrocarbons, lipids, fatty acids, simulated vegetable oils, and methane produced from biological reactions in vivo, or organic compounds and / or biomass optimized as feedstocks to produce biofuels and / or liquid fuels through chemical post-processing. These forms of fuel can be used as renewable / alternative energy sources with low greenhouse gas emissions.

[0116] To provide a specific example of an overall biochemical process for capturing CO2 using oxyhydrogen microorganisms and producing biomass and other useful co-products, a process flow diagram describing a specific embodiment of the invention is provided and explained below. This specific example should not be construed as limiting the invention in any way, but is provided for illustrative purposes only.

[0117] 2 includes an exemplary process flow diagram illustrating one embodiment of the present invention for oxyhydrogen microbial CO capture and lipid-rich biomass production that is converted into JP-8 jet fuel. In this group of embodiments, carbon dioxide-rich flue gas is captured from an emission source such as a power plant, refinery, or cement manufacturer. The flue gas can then be compressed and pumped into a cylindrical anaerobic digester containing one or more acidohydrogen microorganisms, such as, but not limited to, purple non-sulfur photosynthetic bacteria, including, but not limited to, Rhodopseudomonas palustris, Rhodopseudomonas capsulata, Rhodopseudomonas viridis, Rhodopseudomonas sulfoviridis, Rhodopseudomonas blastica, and other Rhodopseudomonas species.

[0118] In some embodiments, Rhodopseudomonas capsulata can be used as the acidohydrogen microorganism, and in some cases, doubling times of 6 hours can be achieved with chemoautotrophic growth using hydrogen. See, e.g., Madigan, Gest, J. Bacteriology (1979) 524-530, which is incorporated herein by reference. In some embodiments, the doubling time of the microorganism can be 6 hours or less. In some embodiments, the dry biomass concentration can be at least about 3 g / l, at least about 4 g / l, or at least 5 g / l at steady state. In some embodiments, the lipid content of the biomass in the acidohydrogen microorganism can be at least about 10%, at least about 20%, at least about 30%, at least about 35%, or at least about 40%. For example, in some embodiments, Rhodopseudomonas palustris can be used as the acidohydrogen microorganism. See, for example, Carlozzi, Pintucci, Piccardi, Buccioni, Minieri, Lambardi, Biotechnol. Lett., (2009) DOI 10.1007 / s10529-009-0183-2, which is incorporated herein by reference. In certain embodiments, the lipid content of the acidohydrogen microbial biomass is at least 40%, there is a steady-state bioreactor cell density of at least 5 g / liter in a continuous process, the doubling time of the microbial organism is at most 6 hours, the process achieves an energy efficiency of at least 40% in the conversion of hydrogen to biomass, and / or at least 60% of the biomass energy content is stored as lipid (which corresponds to a lipid content of the biomass of about 40% by weight).

[0119] In one group of embodiments shown in FIG. 2, the hydrogen electron donor and oxygen and carbon dioxide electron acceptors are continuously added to the growth broth along with other nutrients required for chemical synthesis and culture maintenance and growth that are pumped into the digester. In certain embodiments, the hydrogen source is a carbon dioxide emission-free process. Exemplary carbon dioxide emission-free processes include electrolysis or thermochemical processes powered by energy technologies including, but not limited to, photovoltaic, solar, wind, hydroelectric, nuclear, geothermal, enhanced geothermal, ocean thermal, wave, and tidal. In one group of embodiments shown in FIG. 2, oxygen serves as an electron acceptor in the chemical synthesis reaction for the intracellular production of ATP via the oxyhydrogen reaction associated with oxidative phosphorylation. Oxygen can be generated from flue gas, which can be produced from a water splitting reaction used to make hydrogen, and / or it can be harvested from air. In FIG. 2, carbon dioxide from the flue gas is used to convert ATP, which is generated via the oxyhydrogen reaction, to NAD by H2. + or NADPH +The cell mass serves as an electron acceptor for the synthesis of organic compounds via biochemical pathways utilizing NADH and / or NADPH produced from the intracellular enzyme-catalyzed reduction of β-lactamase and β-lactamase. The culture broth can be continuously removed from the digester and flowed through a membrane filter to separate the cell mass from the broth. The cell mass can then be recycled back to the digester and / or pumped downstream for lipid extraction according to methods known to those skilled in the art. The lipids can then be converted to JP-8 jet fuel using methods known to those skilled in the art of biomass refining (see, for example, USDOE Energy Efficiency & Renewable Energy Biomass Program, "National Algal Biofuels Technology Roadmap", May 2010, which is incorporated herein by reference in its entirety). The cell-free broth that has been passed through the cell mass removal filter can then be subjected to any necessary additional waste removal treatments depending on the flue gas source. The remaining water and nutrients can then be pumped back into the digester.

[0120] Some species of Rhodopseudomonas have a highly versatile metabolism, capable of photoautotrophic, photoheterotrophic, heterotrophic and even chemoautotrophic growth, and can survive in both aerobic and anaerobic environments [Madigan, Gest, J. Bacteriology (1979) 524-530]. In certain embodiments of the present invention, the heterotrophic capabilities of Rhodopseudomonas species are exploited to further improve the efficiency of carbon conversion to energy and lipid products. The non-lipid biomass residue after lipid extraction is primarily composed of proteins and carbohydrates. In a particular embodiment of the invention, as shown in FIG. 2, a portion of the carbohydrate and / or protein residues following lipid extraction are acid hydrolyzed to monosaccharides and / or amino acids, the acid is neutralized, and the solution of monosaccharides and / or amino acids is fed to a second heterotrophic bioreactor containing a species of Rhodopseudomonas that consumes the biomass input and produces additional lipid products.

[0121] The genome of Rhodopseudomonas palustris has been sequenced by the DOE Joint Genome Institute [Larimer et.al (2003) Nature Biotechnology 22,55-61]. Its genetic system has been reported to be particularly amenable to modification. In one group of embodiments of the invention, one or more carbon fixation reactions are performed by Rhodopseudomonas species that have been improved, optimized, or engineered for improved fixation of carbon dioxide and / or other forms of inorganic carbon and / or improved production of organic compounds through methods including, but not limited to, one or more of the following: accelerated mutagenesis, genetic engineering or modification, hybridization, synthetic biology, or traditional selective breeding.

[0122] FIG. 3 includes an exemplary schematic diagram of a bioreactor 300 that can be used in certain embodiments. The bioreactor 300 can be used, for example, as the reactor illustrated as box 4 in FIG. 1 labeled "BIOREACTOR-DETONATING AEROSOL MICROORGANISMS" and / or as the reactor illustrated as box 4 in FIG. 2 labeled "BIOREACTOR-Purple NON-SULFUR BACTERIA". The bioreactor 300 illustrated in FIG. 3 can be operated to take advantage of the low solubility of hydrogen and oxygen gases in water and avoid dangerous mixing of hydrogen and oxygen gases. In addition, the bioreactor can provide the oxygen and hydrogen required for cellular energy and carbon fixation to the oxyhydrogen microorganisms, for example, by sparging, bubbling, or diffusing oxygen or air upwards into a vertical liquid column filled with culture medium.

[0123] Bioreactor 300 includes a first column 302 and a second column 304. In one set of embodiments shown in FIG. 3, oxygen is introduced into first column 302 while hydrogen or syngas is introduced into second column 304, although in other embodiments, the order may be reversed. Oxygen and / or hydrogen and / or syngas can be introduced into each of the columns, for example, by sparging, bubbling, and / or diffusing them upwardly through the culture medium. Bioreactor 300 can include a horizontal liquid connection 312 at the top of the column and a horizontal liquid connection 314 at the bottom of the column.

[0124] In some embodiments, the level of liquid medium in tower 302 is maintained such that a gas headspace 316 forms above the liquid. In addition, in some cases, the level of liquid medium in tower 304 can be arranged such that a gas headspace 318 forms above the liquid medium. In some embodiments, headspace 316 and / or headspace 318 can occupy at least about 2%, at least about 10%, at least about 25%, between 2% and about 80%, between about 10% and about 80%, or between about 25% and about 80% of the total volume of the tower in which they are located. Headspaces 316 and 318 can be isolated from each other by liquid medium. In some embodiments, gases have low solubility in liquid medium, so gases can be bubbled or diffused upward through each of the towers and then collected at the top of the towers. Establishing isolated headspaces can prevent dangerous amounts of hydrogen gas and oxygen gas from mixing with each other. For example, hydrogen gas in one tower can be prevented from mixing with oxygen gas in the other tower (and vice versa). Preventing mixing of hydrogen gas and oxygen gas can be accomplished, for example, by maintaining a connection between the two towers so as to prevent gas transport from one tower to the other by filling with liquid. In some embodiments, the headspace 316 and / or 318 can be maintained substantially constant at the top of the first and second towers as the liquid medium is circulated between them.

[0125] 3, horizontal liquid connection 312 at the top of the towers and horizontal liquid connection 314 at the bottom of the towers are arranged such that with the horizontal liquid connections constantly filled, liquid medium flows upward in the direction of oxygen gas through one tower and countercurrent to hydrogen gas and / or syngas through the other tower. In other embodiments, liquid medium can flow upward through the tower containing hydrogen gas and / or syngas and downward (countercurrent to the gases) through the other tower containing oxygen gas.

[0126] In some embodiments, gas can be forced to bubble through one side or the other (but not both simultaneously) such that a particular tower acts as an airlift reactor to drive the circulation of culture medium between the two towers, and in some embodiments, the circulation of fluid can be assisted by impellers, turbines, and / or pumps.

[0127] In some such embodiments, any unused hydrogen gas and / or syngas (which may terminate in the headspace) that passes through the culture medium without being taken up by the microorganisms can be recirculated by pumping the gas out of the headspace, optionally compressing it, and returning it to the medium at the bottom of the liquid column on the hydrogen and / or syngas side. In some embodiments, oxygen and / or air can be similarly recirculated on its respective side, or alternatively vented after passing through the headspace.

[0128] The oxyhydrogen microorganisms are, in certain embodiments, freely circulated with the broth between the first and second columns, while in other embodiments the oxyhydrogen microorganisms are restricted to the hydrogen side, for example, by using a microfilter that allows the broth to pass but retains the microorganisms on the hydrogen side.

[0129] FIG. 4 includes an exemplary schematic diagram of another method of operation of the bioreactor 300 that can be used in certain embodiments. The bioreactor configuration of FIG. 4 can take advantage of the relatively high solubility of carbon dioxide and / or the ability of oxyhydrogen microorganisms to recover carbon dioxide from relatively dilute streams. The operation illustrated in FIG. 4 can exploit the carbon concentration mechanism inherent to oxyhydrogen microorganisms. Flue gas and / or air containing carbon dioxide can be transported through the oxygen side of the bioreactor. Carbon dioxide can be dissolved in solution and / or taken up by the oxyhydrogen microorganisms and then transported to the hydrogen side of the reactor, for example, via horizontal liquid connection 312 at the top of the column. The hydrogen side can provide reducing equivalents to drive carbon fixation. In some embodiments, other gases (e.g., oxygen, nitrogen, etc.) pumped into the oxygen side have low solubility relative to CO2 and are not carried into the hydrogen side. Rather than being sent from column 302 to column 304, low solubility gases can be transported to headspace 316. In some embodiments, after the gas is delivered to the headspace 316, it may be possible to vent it.

[0130] FIG. 5 includes an exemplary schematic diagram of an electrolysis device 500 that can be used in certain embodiments. The electrolysis device 500 can be used, for example, as the unit illustrated as box 3 in FIG. 1 labeled "electron donor generation" and / or as the unit illustrated as box 3 in FIG. 2 labeled "electrolysis". The electrolysis device 500 can be designed to take advantage of the tolerance and need of oxyhydrogen microorganisms for certain concentrations of oxygen by reducing or eliminating the complete separation of hydrogen and oxygen produced from the electrolysis process, as opposed to the separation schemes utilized in conventional electrolysis systems designed for the production of pure hydrogen. The device 500 includes an electrolysis unit 502 configured to generate H2 and O2 from water. Any suitable electrolysis unit 502 can be utilized to perform the electrolysis process. In some embodiments, it is possible to reduce the electrical resistance in the electrolysis unit 502 at the expense of complete separation of hydrogen and oxygen by means including, but not limited to, one or more of the following: eliminating the separators used to prevent gas crossover in standard electrolysis equipment and / or using a relatively short distance between the positive and negative electrodes.

[0131] The apparatus 500 may include an outlet 504 capable of transporting hydrogen and oxygen produced by the electrolysis unit 502. The outlet 504 may include a separator 506 operable to separate at least a portion of the hydrogen from at least a portion of the oxygen. In certain embodiments, a semi-permeable membrane, such as a polymeric membrane designed for H2 separation, may be utilized as the separator 506. In certain embodiments, the separator 506 may include a metal foil, including but not limited to foils made from palladium, palladium alloys, vanadium, niobium, tantalum, and alloys thereof, and / or other metals and / or alloys that are permeable to hydrogen but less permeable to other gases, such as oxygen. In some embodiments, a separator may be used to separate hydrogen from oxygen such that the hydrogen content of one gas product leaving the separator is enriched to a level desirable for the oxyhydrogen microorganism. The gas product may then be transported to a bioreactor to be used as a feedstock. In certain embodiments, the amount of hydrogen in one of the gas products exiting the separator can be set at a level that maximizes oxyhydrogen microbial activity and minimizes loss of hydrogen produced through the electrolyzer 500.

[0132] The following references are incorporated herein by reference in their entireties for all purposes: U.S. Provisional Patent Application No. 61 / 328,184, filed April 27, 2010, entitled "USE OF ACID-HYDROGEN MICROORGANISMS FOR THE RECOVERY AND CONVERSION OF NON-PHOTOSYNTHETIC CARBON FROM INORGANIC CARBON SOURCES TO USEFUL ORGANIC COMPOUNDS", International Application No. PCT / US2010 / 001402, filed May 12, 2010, entitled "BIOCHEMICAL PROCESS UTILIZING CHEMOAUTOTROPHIC MICROORGANISMS FOR THE CHEMOTIC FIXATION OF CARBON DIOXIDE AND / OR OTHER INORGANIC CARBON SOURCES TO ORGANIC COMPOUNDS AND THE PRODUCTION OF OTHER USEFUL PRODUCTS", and U.S. Publication No. 2010 / 0120104, filed November 6, 2009, entitled "BIOCHEMICAL PROCESS UTILIZING CHEMOAUTOTROPHIC MICROORGANISMS FOR THE CHEMOTIC FIXATION OF CARBON DIOXIDE AND / OR OTHER INORGANIC CARBON SOURCES TO ORGANIC COMPOUNDS AND THE PRODUCTION OF OTHER USEFUL PRODUCTS". EXAMPLES

[0133] The following examples are intended to illustrate certain embodiments of the present invention, but do not exemplify the full scope of the invention.

[0134] Example 1 In this example, oxyhydrogen microorganisms that accumulate high lipid content and / or other valuable compounds such as polyhydroxybutyrate (PHB) were grown in a mineral medium with CO2 as the carbon source and hydrogen acting as the electron donor, with oxygen providing the electron acceptor. Such oxyhydrogen microorganisms can be used in certain embodiments of the invention to convert C1 chemicals, such as carbon dioxide, into long-chain organic chemicals.

[0135] Static anaerobic reactors were inoculated with Cupriavidus necator DSM531, which is capable of accumulating a high percentage of cell mass as PHB. The inoculum was obtained from a DSM medium no. 1 agar plate maintained under aerobic conditions at 28 degrees Celsius. Each anaerobic reactor had 10 ml of liquid medium DSM no. 81 with 80% H2, 10% CO2, and 10% O2 in the headspace. The cultures were incubated at 28 degrees Celsius. Cupriavidus necator had an optical density (OD) of 0.98 at 600 nm and 4.7 × 10 8 A cell density of 100 cells / ml was reached.

[0136] Other growth experiments were performed with Cupriavidus necator (DSM531). The medium used for growth was mineral salts medium (MSM) formulated by Schlegel et al. MSM medium was formed by mixing 1000 ml of medium A, 10 ml of medium B, and 10 ml of medium C. Medium A contained 9 g / l Na2HPO4.12H2O, 1.5 g / l KH2PO4, 1.0 g / l, 0.2 g / l MgSO4.7H2O, and 1.0 ml of trace element medium. Trace element medium contained 1000 ml distilled water, 100 mg / l ZnSO4.7H2O, 30 mg / l MnCl2.4 H2O, 300 mg / l H3BO3, 200 mg / l COCl2.6H2O, 10 mg / l CuCl2.2H2O, 20 mg / l NiCl2.6H2O, and 30 mg / l Na2MoO4.2H2O. Medium B contained 100 ml distilled water, 50 mg ammonium ferric citrate, and 100 mg CaCl2. Medium C contained 100 ml distilled water and 5 g NaHCO3.

[0137] Cultures were grown in 20 ml of MSM medium in 150 ml capped, sealed serum vials with the following gas mixture in the headspace: 71% hydrogen, 4% oxygen, 16% nitrogen, 9% carbon dioxide. Headspace pressure was 7 psi. Cultures were grown at 30 degrees Celsius for 8 days. Cupriavidus necator reached an OD of 0.86 at 600 nm.

[0138] It is known that faster growth rates and higher cell densities can be achieved in larger scale bioreactor devices. Therefore, it is believed that higher growth rates and cell densities can be achieved simply by scaling up the above-described system. For example, Alcaligenes eutrophus, Ralstonia eutropha, and Cupriavidus necator, also known as Hydrogenomona eutropha, have been grown in H2 / CO2 / O2-based bioreactors to cell densities of over 90 grams / liter [Tanaka, Ishizaki; Biotech.And Bioeng.,vol.45,268-275(1995)] with doubling times of less than 2 hours [Ammann,Reed,Durichek,Appl.Microbio.,(1968)822-826].

[0139] Certain preferred embodiments of the invention have been described herein in sufficient detail to enable one skilled in the art to practice the full scope of the invention. However, many possible variations of the invention not specifically described shall still be deemed to be encompassed within the scope of the invention and the appended claims. Thus, these descriptions provided herein are merely added as examples and are not intended to limit the scope of the invention in any way. More generally, one skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are to be considered exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the particular application or applications in which the teachings of the invention are used. One skilled in the art will recognize and be able to ascertain, without any more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Thus, the foregoing embodiments are provided merely by way of example, and it will be understood that, within the scope of the appended claims and their equivalents, the invention may be practiced otherwise than as specifically described and claimed. The present invention relates to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods is encompassed within the scope of the invention, provided that such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent.

[0140] As used in the specification and claims, the indefinite articles "a" and "an" shall be construed to mean "at least one," unless clearly specified to the contrary.

[0141] The term "and / or" as used herein and in the claims shall be construed to mean "either or both" of the elements so conjoined, i.e., elements that are present in some cases conjointly and in other cases disjointly. In some cases, unless clearly specified to the contrary, other elements may be present, whether associated with or not with the elements specifically identified. Thus, for example, a reference "A and / or B," when used in conjunction with open-ended language such as "comprising," may mean in one embodiment A but not B (optionally including elements other than B), in another embodiment B but not A (optionally including elements other than A), and in yet another embodiment both A and B (optionally including other elements), etc.

[0142] As used herein and in the claims, "or" shall have the same meaning as "and / or" specified above. For example, when separating listed items, "or" or "and / or" shall be inclusive, i.e., including not only at least one of the elements or listed elements, but also including more than one, and optionally including additional items not listed. Only terms that clearly indicate otherwise, such as "only one of" or "exactly one of" or "consisting of" as used in the claims, shall mean the inclusion of exactly one of the elements or listed elements. In general, the term "or" as used herein shall be considered as an exclusive option (i.e., "either," "one of," "only one of," or "exactly one of") only when preceded by an exclusive term, such as "either," "one of," "exactly one of," or "exactly one of,". "Consisting essentially of," as used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0143] In the claims, as in the foregoing specification, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," and the like, shall be intended to be open-ended, that is, to mean inclusive without limitation. Only the transitional phrases "consisting of" and "consisting essentially of" shall be intended to be closed or semi-closed transitional phrases, respectively.

Claims

1. 1. A biochemical process for the recovery and conversion of inorganic carbon compounds and / or organic compounds containing only one carbon atom into organic chemicals, comprising: Introducing inorganic carbon compounds and / or organic compounds containing only one carbon atom into an environment suitable for the maintenance of oxyhydrogen microorganisms and / or capable of maintaining an extract of oxyhydrogen microorganisms; converting said inorganic carbon compounds and / or said organic compounds containing only one carbon atom into said organic chemicals and / or precursors thereof via at least one chemosynthetic carbon fixation reaction utilizing said oxyhydrogen microorganism and / or a cell extract containing an enzyme from said oxyhydrogen microorganism in said environment; Including, The above method, wherein the chemical synthesis immobilization reaction is driven, at least in part, by chemical and / or electrochemical energy provided by electron donors and electron acceptors generated chemically and / or electrochemically and / or introduced into the environment from at least one external source outside the environment.

2. The method of claim 1 , wherein the inorganic carbon compound comprises carbon dioxide.

3. 3. The method of claim 1 or 2, wherein the carbon dioxide comprises carbon dioxide gas alone and / or dissolved in a mixture or solution further comprising carbonate ions and / or bicarbonate ions.

4. The method of any one of claims 1 to 3, wherein the inorganic carbon comprises inorganic carbon contained in a solid phase.

5. The method of any one of claims 1 to 4, wherein the organic compounds containing only one carbon atom comprise carbon monoxide, methane, methanol, formate salts, and / or formic acid.

6. 6. The method according to any one of claims 1 to 5, wherein the electron donor and / or organic compound containing only one carbon atom is produced via gasification and / or pyrolysis of organic matter and provided to the oxyhydrogen microorganism as syngas.

7. 6. The method according to any one of claims 1 to 5, wherein the electron donor and / or organic compound containing only one carbon atom is produced via methane steam reforming and provided to the oxyhydrogen microorganism as syngas.

8. 8. The method of claim 6 or 7, wherein the ratio of hydrogen to carbon monoxide in the syngas is adjusted via a water gas shift reaction prior to delivering the syngas to the oxyhydrogen microorganism.

9. 9. The method of any one of claims 1 to 8, wherein the acidohydrogen microorganism comprises an acidohydrogen microorganism selected from one or more of the following categories: purple non-sulfur photosynthetic bacteria, cyanobacteria, and / or green algae.

10. 10. The method of any one of claims 1 to 9, wherein the acidohydrogen microorganism comprises an acidohydrogen microorganism selected from cyanobacteria and / or green algae.

11. The acid hydrogen microorganisms are selected from the group consisting of the following genera: Rhodopseudomonas spp., Rhodospirillum spp., Rhodococcus spp., Rhizobium spp., Thiocapsa spp., Pseudomonas spp., nas species, Hydrogenomonas species, Hydrogenobacter species, Hydrogenovibrio species, Helicobacter species, Xanthobacter species, Hydrogenophaga species The method of any one of claims 1 to 9, comprising an acid hydrogen microorganism selected from one or more of the following: Hydrogenophaga species, Bradyrhizobium species, Ralstonia species, Alcaligenes species, Variovorax species, Acidovorax species, Anabaena species, Scenedesmus species, Chlamydomonas species, Ankistrodesmus species, and Rhaphidium species.

12. The acid hydrogen microorganisms are selected from the group consisting of the following genera: Rhodospirillum spp., Rhizobium spp., Thiocapsa spp., Hydrogenovibrio spp., Helicobacter spp., Xanthobacter spp., Hydrogenophaga spp., Bradyrhizobium spp., 10. The method of claim 1, comprising an acidohydrogen microorganism selected from one or more of the genera: Bacillus subtilis, Bacillus anguicus, Bacillus niger, Bacillus oryzae, Bacillus subtilis ...

13. The electron donor may be any of the following reducing agents: ammonia, ammonium, carbon monoxide, dithionite, elemental sulfur, hydrocarbons, hydrogen, metabisulfite, nitric oxide, nitrite, e.g., sodium thiosulfate (Na ２ S ２ O ３ ) or calcium thiosulfate (CaS ２ O ３ 13. The method of any one of claims 1 to 12, wherein the metals present in the electrolyte include, but are not limited to, one or more of sulfates such as thiosulfates, sulfides such as hydrogen sulfide, sulfites, thionates, thionites, transition metals or their sulfides, oxides, chalcogenides, halides, hydroxides, oxyhydroxides, phosphates, sulfates, or carbonates in the dissolved or solid phase, and conduction or valence band electrons in a solid electrode material.

14. 14. The method of any one of claims 1 to 13, wherein the electron acceptor comprises one or more of the following: carbon dioxide, oxygen, nitrite, nitrate, ferric or other transition metal ions, sulfate, or valence or conduction band holes in the solid electrode material.

15. 15. The method according to any one of claims 1 to 14, wherein the conversion step is preceded by one or more chemical pretreatment steps in which the electron donor and / or the electron acceptor are produced and / or purified from at least one input chemical and / or recycled from chemicals produced during the fixation step and / or from chemicals originating from waste streams from other industrial, mining, agricultural, sewerage or waste generation processes.

16. 16. The method according to any one of claims 1 to 15, wherein the conversion step is followed by one or more process steps in which organic and / or inorganic chemical products of the chemical synthesis are separated from the process stream produced during the conversion step and are treated to produce products in a form suitable for storage, transport and sale, and also one or more process steps in which the cell mass is separated from the process stream and recycled to the environment and / or collected and treated to produce biomass in a form suitable for storage, transport and sale.

17. 17. The method according to any one of the preceding claims, wherein the conversion step is followed by one or more process steps in which waste products and / or impurities and / or pollutants are removed from the process stream produced during the fixation step for disposal.

18. 20. The method of claim 17, wherein the waste products include waste products from a nutrient medium used to support the oxygen-hydrogen reaction.

19. The method according to any one of claims 1 to 18, wherein the conversion step is followed by one or more process steps of recycling any unused nutrients and / or process water remaining after removing the oxyhydrogen cell mass and / or chemical co-products of the chemosynthesis and / or waste products or pollutants of the process streams generated during the fixation step back into the environment to support further chemical synthesis.

20. 20. The method of any one of claims 1 to 19, wherein the electron donor and / or electron acceptor are generated or recycled using a renewable, alternative, or conventional power source with low greenhouse gas emissions, and the power source is selected from at least one of photovoltaic, solar, wind, hydroelectric, nuclear, geothermal, enhanced geothermal, ocean, wave, and tidal power.

21. The electron donor is the following: elemental Fe ０ , siderite (FeCO ３ ), magnetite (Fe ３ O ４ ), pyrite or marcasite (FeS ２ ), pyrrhotite (Fe （１－ｘ） S (x = 0 to 0.2)), iron ore (Fe, Ni) ９ S ８ , purple nickelite (Ni ２ FeS ４ ), Nickel pyrite (Ni,Fe)S ２ , arsenopyrite (FeAsS), or other iron sulfides, realgar (AsS), oroprite (As ２ S ３ ), cobaltite (CoAsS), rhodochrosite (MnCO ３ ), chalcopyrite (CuFeS ２ ), bornite (Cu ５ FeS ４ ), copper indigo (CuS), copperite (CuS), ８ Sb ２ S ７ ), arsenopyrite (Cu ３ A.S. ４ ), arsenic copperite (Cu １２ A.S. ４． S １３ ), chalcocite (Cu ２ S, or other copper sulfides, sphalerite (ZnS), ferroblende (ZnS), or other zinc sulfides, galena (PbS), benzophenone (Pb ５ (Sb, As ２ ) S ８ ), or other lead sulfides, argyrite or goethite (Ag ２ S), molybdenite (MoS ２ ), goethite (NiS), polydymite (Ni ３ S ４ ), or other nickel sulfides, stibnite (Sb ２ S ３ ), Ga ２ S ３ , CuSe, cooperite (PtS), laurite (RuS ２ ), Braggite (Pt, Pd, Ni)S, FeCl ２ The method according to any one of claims 1 to 20, wherein the mineral is produced from a mineral of natural origin selected from one or more of the following:

22. The electron donor is selected from the following: process gas, tail gas, enhanced oil recovery vent gas, biogas, acid mine drainage, landfill leachate, landfill gas, geothermal gas, geothermal sludge or brine, metal contaminants, gangue, tailings, sulfides, disulfides, mercaptans selected from one or more of methyl mercaptan, dimethyl mercaptan and ethyl mercaptan, carbonyl sulfide, carbon disulfide, alkanesulfonates, dialkyl sulfides, thiosulfates, thiofurans, thiocyanates, isothiocyanates, thioisopropyl ethers ...

22. The method of any one of claims 1 to 21, wherein the sour gas is produced from a pollutant or waste product selected from one or more of anates, thioureas, thiols, thiophenols, thioethers, thiophenes, dibenzothiophenes, tetrathionates, dithionites, thionates, dialkyl disulfides, sulfones, sulfoxides, sulfolane, sulfonic acid, dimethylsulfoniopropionate, sulfonate esters, hydrogen sulfide, sulfate esters, organic sulfur, sulfur dioxide, and all other sour gas pollutants or waste products.

23. Introducing hydrogen storage material into the environment in the form of a solid support medium for microbial growth that facilitates the delivery of reducing equivalents from the electron donor to the oxyhydrogen microorganism for one or more chemosynthetic reactions during the immobilization step, placing the absorbed or adsorbed hydrogen electron donor in close proximity to the chemoautotrophic organism; ２ 23. The method of any one of claims 1 to 22, which is kinetically and / or thermodynamically enhanced by one or more of: introducing an electron carrier that assists in transferring reducing power from a poorly soluble electron donor comprising electrons in a gas or solid electrode material to the chemoautotrophic culture medium; and introducing an electrode material in the form of a solid growth support medium directly into the environment, which facilitates placing solid electrons in close proximity to the chemoautotrophic organism.

24. 24. The method of any one of claims 1 to 23, wherein the organic chemicals comprise compounds with carbon chain lengths of from C5 to C30.

25. 25. The method according to any one of claims 1 to 24, wherein at least one chemical synthesis reaction is carried out by an improved, optimized or engineered oxyhydrogen microorganism, fixation of inorganic carbon compounds and / or organic compounds containing only one carbon atom and production of organic compounds through a method comprising one or more of the following: accelerated mutagenesis, genetic engineering or genetic modification, hybridization, synthetic biology, and traditional selective breeding.

26. a first tower including an upper section and a lower section; a second tower including an upper section and a lower section; an upper section of the second column fluidly connected to an upper section of the first column, and a lower section of the second column fluidly connected to a lower section of the first column, constructed and arranged so that when circulating liquid between said first and second columns, a volume of gas is substantially constant at the top of said first column and / or said second column; and A bioreactor, wherein the volume of gas occupies at least about 2% of the total volume of the column in which it is located.

27. 27. The bioreactor of claim 26, wherein the bioreactor contains a liquid medium.

28. 27. The bioreactor of claim 26, wherein the bioreactor contains an oxygen-hydrogen microorganism.

29. 1. A method of operating a bioreactor comprising circulating a liquid comprising a growth medium between a first column and a second column, wherein during operation a volume of gas is maintained substantially constant at the top of said first column and / or said second column, and wherein the volume of gas occupies at least about 2% of the total volume of the column in which it is located.

30. 30. The method of claim 29, wherein the volume of gas comprises hydrogen and / or oxygen.

31. 30. The method of claim 29, wherein the volume of gas comprises hydrogen.

32. 30. The method of claim 29, wherein the volume of gas occupies from about 2% to about 10% of the total volume of the column in which it is located.

33. 30. The method of claim 29, wherein the first and / or second column includes an inlet section, and at least a portion of the gas located at the top of the column is recirculated from the volume via the inlet section of the first and / or second column back to the first and / or second column.

34. 30. The method of claim 29, wherein the bioreactor contains an acid-hydrogen microorganism.

35. a chamber constructed and arranged to electrolyze water to produce oxygen and hydrogen; an outlet portion including a separator constructed and arranged to separate at least a portion of the oxygen in the stream from at least a portion of the hydrogen in the stream such that the hydrogen content of the fluid exiting the separator is suitable for use as a feed stream to a reactor containing a culture of oxyhydrogen microorganisms; 13. An electrolysis apparatus comprising:

36. 36. The electrolysis apparatus of claim 35, wherein an outlet of the electrolysis apparatus is coupled in fluid communication with a bioreactor.

37. 37. The electrolysis apparatus of claim 36, wherein the bioreactor is constructed and arranged for the recovery and conversion of inorganic carbon compounds and / or organic compounds containing only one carbon atom to organic chemicals by oxyhydrogen microorganisms.

38. A method of operating an electrolysis apparatus comprising electrolyzing water to produce a first stream containing oxygen and hydrogen; and separating at least a portion of the oxygen from at least a portion of the hydrogen to produce a second stream that is relatively hydrogen-rich compared to the first stream; The process wherein the second stream is suitable as a feed stream to a reactor containing a culture of an oxyhydrogen microorganism.

39. 40. The method of claim 38, comprising feeding the second stream to a bioreactor.

40. 40. The method of claim 39, wherein the bioreactor contains an acid-hydrogen microorganism.

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