Use of oxyhydrogen microorganisms for non-photosynthetic carbon capture and conversion of inorganic and/or C1 carbon sources into useful organic compounds
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 CI carbon sources including but not limited to carbon monoxide, methane, methanol, formate, or formic acid, and/or mixtures containing CI chemicals including but not limited to various syngas compositions, into organic chemicals including biofuels or other valuable biomass, chemical, industrial, or pharmaceutical products are provided. The present invention, in certain embodiments, fixes inorganic carbon or CI carbon sources into longer carbon chain organic chemicals by utilizing microorganisms capable of performing the oxyhydrogen reaction and the autotrophic fixation of CO 2 in one or more steps of the process.
1. A biological and chemical method to form an organic chemical product, comprising:
introducing an inorganic carbon compound and/or an organic compound containing only one carbon atom into a bioreactor comprising an environment suitable for maintaining oxyhydrogen microorganisms from genus Xanthobacter , wherein the environment comprises the oxyhydrogen microorganisms in a liquid culture medium; and
converting the inorganic carbon compound and/or the organic compound containing only one carbon atom into biomass and/or an organic chemical product comprising a lipid, an amino acid, a peptide, and/or a protein within the environment via a carbon-fixing step that carries out at least one chemosynthetic carbon-fixing reaction utilizing the oxyhydrogen microorganisms;
wherein the at least one chemosynthetic carbon-fixing reaction is at least partially driven by chemical and/or electrochemical energy provided by electron donors comprising gaseous H 2 and electron acceptors comprising gaseous O 2 ,
wherein O 2 gas is introduced into a first column comprising the oxyhydrogen microorganisms and liquid culture medium within the environment by sparging, bubbling, and/or diffusion of said O 2 gas, and H 2 gas and/or syngas containing the H 2 gas is introduced into a second column comprising the oxyhydrogen microorganisms and liquid culture medium within the environment by sparging, bubbling, and/or diffusion of said H 2 gas and/or syngas, wherein the first and second columns are separated from each other, a headspace of the first column and a headspace of the second column are isolated from each other by the liquid culture medium, and there is a liquid connection between the first and second columns comprising the liquid culture medium, and wherein the liquid culture medium circulates between the first and second columns,
wherein the carbon-fixing reaction is maintained using a continuous influx and removal of the liquid culture medium and/or biomass from the environment,
wherein surplus biomass is removed from the environment in order to maintain a constant population and cell density of said oxyhydrogen microorganisms in the liquid culture medium, and
wherein the biomass and/or the organic chemical product is separated from the liquid culture medium and processed into a fuel product, a nutritional product, an animal feed, a fertilizer, a soil additive, a soil stabilizer, a carbon source for fermentations, and/or a nutrient source for growth of other microbes or organisms.
2. The method of claim 1 , wherein the inorganic carbon compound is carbon dioxide.
3. The method of claim 2 , wherein the carbon dioxide is in a form of carbon dioxide gas and/or in a form of carbonate ion and/or bicarbonate ion dissolved in the liquid culture medium.
4. The method of claim 1 , wherein concentrations of the electron donors and the electron acceptors are targeted at constant levels over time in a steady state maintained for maximum uptake and fixation of the inorganic carbon compound and/or the organic compound containing only one carbon atom, and/or for maximum production of the organic chemical product.
5. The method of claim 1 , wherein gas phase mixtures of said gas H 2 gas and said O 2 gas with a H 2 concentration in a range from 4% to 74.5% are avoided in the environment.
6. The method of claim 1 , wherein the organic compound containing only one carbon atom is carbon monoxide, methane, methanol, formate, or formic acid.
7. The method of claim 1 , wherein the electron donors and/or the organic compound containing only one carbon atom are generated through electrolysis of water, gasification and/or pyrolysis of organic matter, or methane steam reforming, which is provided as the syngas to the oxyhydrogen microorganisms.
8. The method of claim 7 , wherein a ratio of hydrogen to carbon monoxide in the syngas is adjusted via a water gas shift reaction prior to the syngas being delivered to the oxyhydrogen microorganisms.
9. The method of claim 1 , wherein the method further comprises generating or recycling the H 2 gas using renewable, alternative, or conventional sources of power that are low in greenhouse gas emissions, wherein the sources of power are selected from photovoltaics, solar thermal power, wind power, hydroelectric power, nuclear power, geothermal power, enhanced geothermal power, ocean thermal power, ocean wave power, and tidal power.
10. The method of claim 1 , wherein the bioreactor does not comprise transparent materials that expose the oxyhydrogen microorganisms to light.
11. The method of claim 1 , wherein a feed gas comprising the O 2 gas at a concentration from 2% to 12% is introduced into the first column in the environment.
12. The method of claim 1 , wherein the H 2 gas and/or syngas that is not utilized by the oxyhydrogen microorganisms in the at least one chemosynthetic carbon-fixing reaction passes through the liquid culture medium into the gas headspace of the second column and is recirculated by pumping the unutilized H 2 gas and/or syngas out of the headspace, compressing it, and pumping it back into the liquid culture medium.
13. The method of claim 12 , wherein the unutilized H 2 gas and/or syngas is pumped back into the liquid culture medium at the bottom of the second column.
14. The method of claim 1 , wherein the converting step is preceded by one or more chemical processing steps in which the electron donors and/or the electron acceptors are generated and/or refined from at least one input chemical and/or recycled from chemicals produced during the carbon-fixing step and/or chemicals derived from waste streams from other industrial, mining, agricultural, sewage or waste generating processes.
15. The method of claim 1 , wherein the converting step is followed by one or more process steps in which any unused nutrients and/or process water left after removal of the biomass and/or the organic chemical product are recycled back into the environment to support further chemosynthesis.
16. The method of claim 11 , wherein said O 2 gas is delivered to the first column in the environment at a concentration in a range of 2% to 6%.
17. The method of claim 1 , wherein generation of said H 2 gas comprises one or more of the following: electrolysis of water; thermochemical splitting of water through one or more cycles selected from an 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 splitting of hydrogen sulfide; the Kvaerner-process; and gasification or pyrolysis of biomass.
18. The method of claim 1 , wherein the oxyhydrogen microorganisms freely circulate along with the liquid culture medium between the first and second columns.