Production of carbon material from low concentration co2 via microbial co2 reduction and pyrolysis

Abstract

A system and method for sequestration and reduction of carbon dioxide (CO2) to a carbon material via an integrated microbial and chemical catalytic processes are described. The system and method comprise a bioreactor in gas communication with a pyrolysis reactor, wherein the microbes of the bioreactor uptake CO2 dissolved in aqueous solution and convert it to a volatile organic carbon compound, such as, for example, methane, which, in turn is fed into the pyrolysis reactor for catalytic conversion to a carbon material, wherein the carbon material may include crystalline carbon. The thus obtained carbon material is easily collectable for various high end uses or for CO2 storage.

Description

PRODUCTION OF CARBON MATERIAL FROM LOW CONCENTRATION CO2 VIA MICROBIAL CO2 REDUCTION AND PYROLYSISCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The current application claims the benefit of and priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 63 / 693, 101 , entitled “Production of Crystalline Carbon Material from Low Concentration CO2 via Microbial Methanogenesis and Methane Pyrolysis”, filed September 10, 2024, the disclosure of which is incorporated herein by reference in its entirety for all purposes.FIELD OF THE INVENTION

[0002] The current disclosure is generally directed to a system and method for sequestration of carbon dioxide (CO2) to carbon at the oxidation state of zero via an integration of microbial and chemical catalytic processes.BACKGROUND OF THE INVENTION

[0003] The escalating levels of atmospheric carbon dioxide (CO2) represent a critical challenge in the global effort to mitigate climate change. Furthermore, capture and removal of low concentration CO2, e.g., from the atmosphere or CO2 emissions sources, is thermodynamically expensive because the gas is diluted, e.g., in air at 420 ppm. Therefore, there exists a dire and urgent need for efficient, scalable, and cost-effective technology platforms for CO2 capture, utilization, and sequestration.SUMMARY OF THE INVENTION

[0004] Various embodiments are directed to a system for reduction of CO2 to a carbon material including: a bioreactor at least including a CO2-reducing compartment, characterized by a compartment temperature and a compartment pressure, wherein the CO2- reducing compartment further includes one or more CO2-reducing microbial cultures;a pyrolysis reactor, characterized by a pyrolysis temperature and a pyrolysis pressure; and a CO2 capture unit including an alkaline aqueous solution; and a supply of metabolizable electrons; wherein the bioreactor is in fluid communication, direct or indirect, with the CO2 capture unit and, separately, in direct fluid communication with the supply of metabolizable electrons; and in gas communication, direct or indirect with the pyrolysis reactor.

[0005] In various such embodiments, the one or more CO2-reducing microbial cultures are methanogenic microbial cultures.

[0006] In still various such embodiments, the bioreactor includes at least one additional compartment, wherein the at least one additional compartment is a pretreatment compartment in fluid communication with the CO2-reducing compartment and either the CO2 capture unit or the supply of metabolizable electrons or both, such that the pre-treatment compartment is situated between the CO2-reducing compartment and either the CO2 capture unit or the supply of metabolizable electrons or all three; and wherein the pre-treatment compartment includes at least one microbial culture capable of consuming or neutralizing contaminants harmful to the one or more CO2-reducing microbial cultures.

[0007] In still yet various embodiments, the pre-treatment compartment includes at least one 02-consuming microbial culture.

[0008] In yet still various such embodiments, the at least one 02-consuming microbial culture is a microbe selected from the group consisting of: a hydrogen oxidizing bacterium, a yeast, and any combination thereof.

[0009] In yet various such embodiments, the one or more CO2-reducing microbial cultures are immobilized or retained on a support.

[0010] In various such embodiments, the support includes a high surface area material selected from the group consisting of: polyurethane foam, clay and clay-like pellets, carbon, metal, molecular sieve and any combination thereof.

[0011] In still various such embodiments, the supply of metabolizable electrons is a supply of H2.

[0012] In yet still various such embodiments, the compartment pressure is 1 — 10 atm.

[0013] In still yet various such embodiments, the compartment temperature is room temperature or higher temperature compatible with the one or more CO2-reducing microbial cultures and their activity.

[0014] In yet various such embodiments, the compartment temperature is a temperature suitable for growth of psychrophilic, mesophilic, thermophilic or hyperthermophilic microorganisms.

[0015] In various such embodiments, the pyrolysis reactor includes a pyrolysis catalyst.

[0016] In still various such embodiments, the pyrolysis catalyst includes a transition metal from the first series supported on a metal oxide support.

[0017] In yet still various such embodiments, the transition metal is an element selected from the group consisting of: Ni, Co, Fe, and any combination thereof.

[0018] In still yet various such embodiments, the pyrolysis temperature is 400 — 1 ,500 °C.

[0019] In yet various such embodiments, the system further includes a liquid reservoir situated between and in fluid communication with the CO2 capture unit and the bioreactor.

[0020] In various such embodiments, the system further includes a gas reservoir situated between and in gas communication the bioreactor and the pyrolysis reactor.

[0021] In still various such embodiments, the system further inlcudes a gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit.

[0022] In still yet various embodiments, the system further includes: a liquid reservoir situated between and in fluid communication with the CO2 capture unit and the bioreactor; a gas reservoir situated between and in gas communication the bioreactor and the pyrolysis reactor; anda gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit, or any combination thereof.

[0023] Various other embodiments are directed to a method for reduction of CO2 to a carbon material including: providing a system including: a bioreactor at least including a CO2-reducing compartment, characterized by a compartment temperature and a compartment pressure, wherein the CO2- reducing compartment further includes one or more CO2-reducing microbial cultures; a pyrolysis reactor, characterized by a pyrolysis temperature and a pyrolysis pressure; and a CO2 capture unit including an alkaline aqueous solution; and a supply of metabolizable electrons; wherein the bioreactor is in fluid communication, direct or indirect, with the CO2 capture unit and, separately, in direct fluid communication with the supply of metabolizable electrons; and in gas communication, direct or indirect with the pyrolysis reactor; flowing a gaseous stream including CO2 in a CO2 concentration through the CO2 capture unit to dissolve and capture CO2, thus affording a DIC-enriched solution; flowing the DIC-enriched solution into the bioreactor, while also flowing the supply of metabolizable electrons into bioreactor; allowing the one or more CO2-reducing microbial cultures to consume CO2 from the DIC-enriched solution such as to produce a volatile bioreactor product; collecting the volatile bioreactor product as a gas; flowing the volatile bioreactor product into the pyrolysis reactor; and allowing the volatile bioreactor product to undergo pyrolysis to obtain the carbon material and additional gaseous co-products.

[0024] In various such embodiments, the bioreactor includes at least one additional compartment, wherein the at least one additional compartment is a pre-treatment compartment in fluid communication with the CCh-reducing compartment and either the CO2 capture unit or the supply of metabolizable electrons or both, such that the pretreatment compartment is situated between the CO2-reducing compartment and either the CO2 capture unit or the supply of metabolizable electrons or all three; and wherein the pre-treatment compartment includes at least one microbial culture capable of consuming or neutralizing contaminants harmful to the one or more CO2-reducing microbial cultures.

[0025] In still various such embodiments, the pre-treatment compartment includes at least one 02-consuming microbial culture.

[0026] In various such embodiments, the volatile bioreactor product is a molecule, volatile at the compartment temperature and the compartment pressure, selected from the group including: CH4 or another hydrocarbon, methanol or another alcohol, and an acid.

[0027] In still yet various embodiments, the volatile bioreactor product is CH4.

[0028] In yet still various such embodiments, the supply of metabolizable electrons is a supply of H2.

[0029] In yet various such embodiments, the supply of H2 is characterized by an H2 concentration of 0 to 100 %.

[0030] In various such embodiments, the carbon material is any allotrope of crystalline carbon.

[0031] In still various such embodiments, the carbon material includes any form of carbon nanotubes.

[0032] In yet still various such embodiments, the gaseous stream is an industrial plant emissions stream.

[0033] In still yet various such embodiments, the CO2 concentration is 0.04 to 9 %.

[0034] In yet various such embodiments, the CO2 concentration is 5 %.

[0035] In various such embodiments, the system further includes a liquid reservoir for collecting the DIC-enriched solution prior to its introduction to the bioreactor, wherein theliquid reservoir is situated between and in fluid communication with the CO2 capture unit and the bioreactor; and further wherein the liquid reservoir is used to control the flowing the DIC-enriched solution into the bioreactor.

[0036] In still various such embodiments, the system further includes a gas reservoir for collecting the volatile bioreactor product prior to its introduction to the pyrolysis reactor, wherein the gas reservoir is situated between and in gas communication with the bioreactor and the pyrolysis reactor; and further wherein the gas reservoir is used to control the flowing the volatile bioreactor product into the pyrolysis reactor.

[0037] In yet still various such embodiments, the system further includes a gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit.

[0038] In still yet various such embodiments, the system further includes: a liquid reservoir situated between and in fluid communication with the CO2 capture unit and the bioreactor; a gas reservoir situated between and in gas communication the bioreactor and the pyrolysis reactor; and a gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit, or any combination thereof; and further wherein the liquid reservoir, the gas reservoir, and the gas-liquid separation unit are used to control the system’s processes.

[0039] Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification or may be learned by the practice of the disclosed subject matter. A further understanding of the nature and advantages of the present disclosure may be realized by reference to the remaining portions of the specification and the drawings, which forms a part of this disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0040] These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in conjunction with the accompanying data and figures, wherein:

[0041] FIGs. 1A through 1K illustrate, schematically and with photographs, various aspects and configurations of the system for carbon dioxide (CO2) reduction from a gaseous stream comprising CO2 to a carbon material via combined CO2 capture afforded by a CO2 capture unit, microbial catalytic reduction afforded by a bioreactor supplied with metabolizable electrons, and pyrolysis afforded by a pyrolysis reactor, wherein FIGs. 1A through 1G illustrate various aspects and configurations related to the bioreactor of the system, while FIGs. 1H through 1K illustrate various aspects and configurations related to the pyrolysis reactor of the system; and further wherein, more specifically, FIG. 1A illustrates schematically a configuration of the system wherein a single CO2-reducing compartment of the bioreactor supplied with metabolizable electrons is connected directly to the CO2 capture unit comprising an alkaline aqueous solution used to capture and dissolve CO2 (as DIC) from the gaseous stream, a gas-liquid separation chamber / unit, positioned between the bioreactor and the pyrolysis reactor and in fluid communication with both, and various other auxiliary components of the system; FIG. 1 B illustrates schematically a configuration of the system of FIG. 1A that further includes one pretreatment compartment for removal of contaminants harmful to CO2-reducing microbial cultures from the metabolizable electrons and the DIC-enriched solution; and the gas reservoir; FIG. 1C illustrates schematically a configuration of the system of FIG. 1A that further includes two distinct sources of metabolizable electrons and two pre-treatment compartments, connected in series, for removal of contaminants harmful to CO2-reducing microbial cultures from the two sources of metabolizable electrons ; FIG. 1D illustrates schematically a configuration of the system shown in FIG. 1A, wherein the system further includes a liquid reservoir situated between and in fluid communication with the CO2 capture unit and the CO2-reducing compartment of the bioreactor; and a gas reservoir situated between and in fluid communication with the gas-liquid separation unit and thepyrolysis reactor; FIG. 1 E illustrates schematically a configuration of the system of FIG. 1 D that further includes a support for cell retention within the C02-reducing compartment; and a membrane filter for biomass removal from the bioreactor’s effluent for recycling into the CO2 capture unit; FIG. 1 F illustrates schematically a configuration of the system of FIG. 1 E that further includes a heat recovery unit to recover heat produced by the bioreactor and a membrane for cell retention in the CO2 reduction compartment; FIG. 1G provides a photographic image illustrating a laboratory-scale production setup of the bioreactor, wherein the bioreactor is set-up for an alkaline CO2 capture, microbial O2 removal, and microbial methane production in two trickle bed reactors supplied with metabolizable electrons via H2 produced from water electrolysis; FIG 1 H schematically illustrates a configuration of the system wherein the pyrolysis reactor relies only on heat and no pyrolysis catalyst to afford the carbon material, and also integrates heat recovery from the pyrolysis process and by-products; FIG 11 illustrates schematically a configuration of the system wherein the pyrolysis reactor utilizes plasma generated via electricity to afford the carbon material, and temporarily stores effluent gas or gases in an effluent gas reservoir for later use in the bioreactor; FIG. 1 J illustrates schematically a configuration of the system wherein the pyrolysis reactor relies on a recycled pyrolysis catalyst to afford the carbon material; while FIG, 1 K provides a photographic image illustrating a laboratory-scale production setup of the pyrolysis reactor, wherein the pyrolysis reactor is set up for catalytic pyrolysis of 20 vol. % microbially produced methane and H2 fed from a reservoir to a reactor inside a furnace, followed by gaseous co-product and remaining feedstock collection in another reservoir, in accordance with embodiments of the application.

[0042] FIGs. 2A through 2C schematically illustrate various aspects and configurations of the system and method for CO2 reduction from a gaseous stream comprising CO2 to a carbon material via combined CO2 capture afforded by a CO2 capture unit, microbial catalytic reduction afforded by a bioreactor supplied with metabolizable electrons, and pyrolysis afforded by a pyrolysis reactor, wherein FIG. 2A generally illustrates the system and method; FIG. 2B illustrates schematically the system and method wherein the gaseous stream also contains O2 contamination; and FIG. 2Cillustrates schematically the system and method wherein the system comprises more than one bioreactor to produce a volatile bioreactor product, which is collected in a gas collection reservoir prior to being flown into the pyrolysis reactor, in accordance with embodiments of the application.

[0043] FIGs. 3A and 3B provide microscopy images of the carbon material produced from CO2 via the combined microbial and chemical catalyzed process, wherein FIG. 3A shows SEM (Scanning Electron Microscopy) micrometer scale images of carbon nanotubes produced by CO2 reduction to carbon via combined microbial and chemical catalyzed process; while FIG. 3B shows three TEM (Transmission Electron Microscopy) micrometer scale images of carbon nanotubes produced by combined microbial and thermochemical CO2 reduction to carbon, in accordance with embodiments of the application.

[0044] FIGs. 4A through 4D provide results from characterization of the CO2-derived carbon material, wherein FIG. 4A shows thermogravimetric analysis results from heating the CO2-derived carbon material sample under air, wherein the carbon material had been produced via CO2-derived Ch pyrolysis at 700°C, 800°C, and 900°C (from top to bottom data points); FIG. 4B shows results from Raman spectroscopy, wherein the intensity ratio of the G peak (-1580 cm"1, graphitic carbon) to the D peak (-1350 cm"1, defective / disordered carbon) is highlighted to reflect the degree of graphitic ordering (top data points), while the 2D (-2700 cm"1) to G peak ratio is highlighted to provide insight into the number of stacked graphene layers (bottom data points); FIG. 4C shows the pronounced 002 peak at 26.35°, characteristic of graphitic carbon; and FIG. 4D shows the results from Bragg’s law calculations to define the degree of graphitic ordering of the CO2-derived carbon material to be within the observed range for synthetic graphite, in accordance with embodiments of the application.

[0045] FIG. 5 provides a comparison of the carbon material obtained in accordance with embodiments of the application to commercially available carbon nanomaterials and amorphous carbon.DETAILED DISCLOSURE

[0046] Turning to the schemes, images, and data, embodiments of a system and a method for carbon dioxide (CO2) reduction to a carbon material via a combined microbial and chemical catalytic processes is described. In many embodiments, the system comprises an integrated microbial and catalytic chemistry system comprising a bioreactor, in gas communication with a pyrolysis reactor; while the method comprises flowing a gaseous stream comprising CO2 into the system and using the system to capture CO2 from the gaseous stream and to convert the captured CO2 to a carbon material comprising reduced carbon at the oxidation state of zero. In many embodiments, the bioreactor further comprises one or more compartments, each characterized by a compartment temperature and a compartment pressure, in fluid communication with each other, wherein each compartment is designed to facilitate a specific step or a bioconversion of the method and or comprising a single or a mixture of microorganisms. In some embodiments, the compartments are fed in series. In many embodiments, the bioreactor comprises at least one CO2-reducing compartment designed to reduce CO2 (from the gaseous stream) to a volatile bioreactor product, wherein the CO2-reducing compartment comprises one or more CO2-reducing microbial cultures, altogether capable of reducing CO2 to the volatile bioreactor product. For example, in some embodiments, the one or more CO2-reducing microbial cultures comprise one type of a microbe that reduces CO2 to the volatile bioreactor product. However, in some other embodiments, the one or more CO2-reducing microbial cultures comprise two different types of microbes, wherein each type simultaneously reduces CO2 to the volatile bioreactor product. In yet some other embodiments, the one or more CO2-reducing microbial cultures comprise one type of a microbe that partially converts CO2 to an intermediate to the volatile bioreactor product, and another type of a microbe that uptakes the intermediate to the volatile bioreactor product and converts it to the volatile bioreactor product. In still yet some other embodiments, the one or more CO2-reducing microbial cultures comprise additional microbes that do not directly participate in the reduction of CO2 to the volatile bioreactor product, yet are active in another biological process that benefits the activity of the directly CO2-reducing microbial cultures. For example, in somesuch embodiments, the additional microbes are capable of converting sulfates to sulfides, wherein sulfides react with and, as such, remove, contaminant O2 from the microbial medium, thus improving the activity of the directly CCh-reducing microbial cultures. In many embodiments, the one or more CC>2-reducing microbial cultures comprise methanogenic microbial cultures. In many embodiments, the methanogenic microbial cultures comprise a single pure culture or mixed cultures of methanogenic archaea. In some embodiments, the bioreactor comprises one or multiple compartments for chemical processing or filtering steps of the method, wherein such compartments are in fluid communication with and situated before and or after any of the compartments of the bioreactor comprising microbial cultures.

[0047] In addition, in some embodiments, the bioreactor further comprises one or more pre-treatment compartments connected in series and preceding the CO2-reducing compartment, wherein the one or more pre-treatment compartments are designed to remove contaminants that might inhibit or in any other way affect the activity of the CO2- reducing microbial cultures (e.g., CN, CI2, and or O2) from the gaseous stream. In many such embodiments, the one or more pre-treatment compartments comprise a single or a mixture of organisms capable of consuming or neutralizing the contaminants. In some embodiments, the contaminants is O2 and the bioreactor comprises an 02-removing pretreatment compartment comprising one or more 02-consuming microbial cultures, such as, for example, hydrogen oxidizing bacteria or yeast. In some other embodiments, the one or more pre-treatment compartments are utilized to hydrate the metabolizable electrons to prevent water loss. In some embodiments, the one or more pre-treatment compartments are utilized to treat the bioreactor’s effluent by, for example, passing ozone through the effluent’s liquid to kill microbes, prior to recirculating the effluent to a CO2 capture unit.

[0048] In many embodiments, the compartment pressure is 1 — 10 atm. However, in some embodiments, the compartment pressure is a moderate pressure of 1 — 1 .5 atm. In many embodiments, the compartment temperature is room temperature or higher temperature compatible with the microorganisms comprised within a compartment and their activities. More specifically, in some such embodiments, the compartmenttemperature is a temperature suitable for psychrophilic, mesophilic, thermophilic, or hyperthermophilic microbes. In some embodiments, the compartment temperature is a temperature in the range of 20 — 80 °C. In some embodiments, the compartment temperature is 30°C. In some embodiments, the compartment’s temperature is 37°C. In some embodiments, the compartment temperature is 65°C.

[0049] In many embodiments, the microorganisms of the bioreactor are immobilized on a support, while in some other embodiments, the microorganisms are in solution, while in yet other embodiments, the microorganisms are immobilized on the support and in solution. In many embodiments, the support is a nonbiodegradable support, such as, for example, a material selected from the group consisting of, but not limited to: a high surface area plastic, such as, for example, a polyurethane foam; clay and clay-like pellets; molecular sieve; porous carbon and porous carbon pellets; corrosive-resistant metal, and any combination thereof. In some embodiments, microorganisms are retained via membrane separations.

[0050] In many embodiments the bioreactor is also in fluid communication, directly or indirectly, with a CO2 capture unit comprising an alkaline aqueous solution used to capture and dissolve CO2 (as DIC) from the gaseous stream, and, separately, a supply of microbially metabolizable electrons. In many embodiments, the alkaline aqueous solution further comprises trace minerals and mineral salts to enable microbial growth in the bioreactor, including but not limited to: chlorides, sodium, sulfates, phosphates, ammonium, nitrates, iron, calcium, magnesium, potassium, cobalt, zinc, selenium, tungsten, and any combination thereof. In some embodiments, the supply of microbially metabolizable electrons is selected from the group comprising, but not limited to: a supply of H2; a supply of CO; a supply of other reduced compounds; a supply of biological cofactors, such as, for example, ferredoxin; and any combination thereof. In some embodiments, the supply of metabolizable electrons is provided via electrolysis in situ within the bioreactor. However, it should be noted that, in many embodiments, the supply of metabolizable electrons is delivered from any convenient source. For example, in the embodiments wherein the supply of metabolizable electrons is the supply of H2, H2 is sourced from any convenient H2 source, including, but not limited to: electrolysis, CH4pyrolysis, geological H2, H2 evolved as a product from another chemical or biochemical process, and any combination thereof. In some such embodiments, the supply of H2 comprises 100 % H2. However, in some embodiments, the supply of H2 is diluted or contaminated with other gaseous compounds, including, but not limited to: CH4, O2, H2O, CO, H2S, CO2, NH3, N2, HCN, or CI2. As such, in some embodiments, wherein the supply of metabolizable electrons comprises contaminants that might inhibit or otherwise affect activity of the one or more CO2-reducing microbial cultures, additional pre-treatment compartment or compartments are utilized to remove the contaminants from the supply of metabolizable electrons prior to the supply of metabolizable electrons contacting the one or more CO2-reducing microbial cultures. For example, in some embodiments, wherein the supply of metabolizable electrons also comprises an O2 contamination, the additional pre-treatment compartment or compartments are utilized, wherein the additional compartment or compartments comprise one or more 02-consuming microbial cultures, such as, for example, hydrogen oxidizing bacteria or yeast. As another example, in some embodiments, wherein the supply of metabolizable electrons comprises a CO contamination, the additional pre-treatment compartment or compartments are utilized, wherein the additional compartment or compartments comprise a CO-consuming microbial cultures. In some embodiments, wherein the supply of metabolizable electrons comprises multiple undesirable contaminants, a plurality of additional pre-treatment compartments connected in series and preceding the CO2-reducing compartment are utilized as described herein to remove the multiple undesirable contaminants prior to the supply of metabolizable electrons contacting the CO2-reducing microbial cultures.

[0051] In some embodiments, the bioreactor is also in fluid and gas communication with a gas-liquid separation unit, wherein the gas-liquid separation unit is also in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit. In many such embodiments, the gas-liquid separation unit aids in separation and purification of the gaseous and liquid products and by-products of the bioreactor, as well as biomass and other unwanted volatile contaminants (e.g., H2O, N2, H2S, biomass, and other precipitates), and allows for recirculation of the bioreactor liquids. In many embodiments, the gas-liquid separation unit is an implement selected from the groupscomprising: a distillation column, a centrifuge, a membrane-based filtration system, and any combination thereof.

[0052] In many embodiments, the pyrolysis reactor is characterized by a pyrolysis temperature and a pyrolysis pressure. In some embodiments, the pyrolysis reactor comprises plasma. In many embodiments, the pyrolysis reactor comprises a pyrolysis catalyst that can afford a conversion of a hydrocarbon or alcohol to a carbon and molecular hydrogen. In many such embodiments, the pyrolysis catalyst comprises a transition metal from the first series supported on a metal oxide support. In many embodiments, the transition metal is an element selected from the group comprising: Ni, Co, Fe, and any combination thereof. In many embodiments, the pyrolysis temperature is 400 — 1 ,500 °C. Notably, in many embodiments, the pyrolysis temperature is a temperature sufficient to break C-H and or C-0 bonds of compounds within a feedstock to the pyrolysis reactor in the absence of O2, with or without the help of the pyrolysis catalyst, and to maintain dynamic fluid properties necessary for successful conversion of the feedstock to the carbon material. In some embodiments, utilizing the pyrolysis reactor without the pyrolysis catalyst to obtain the carbon material requires higher temperatures, as compared to the temperatures required for a pyrolysis with the pyrolysis catalyst. In some embodiments, a combination of plasma and high temperature are utilized within the pyrolysis reactor in the absence of the pyrolysis catalyst. It should also be noted here that it is critically important to maintain an 02-free environment within the pyrolysis reactor to avoid the formation of CC from the feedstock wherein the feedstock comprises CO, hydrocarbon or alcohol. In many embodiments, the pyrolysis pressure is 0 to 30 bar.

[0053] Accordingly, in many embodiments, the gaseous stream comprising CO2 in a CO2 concentration is flown (fed) into the system described herein to produce the carbon material for various applications or CO2 storage. In many such embodiments, the gaseous stream comprising CO2 is first contacted by the alkaline aqueous solution within the CO2 capture unit to selectively dissolve and capture CO2, affording a DIC-enriched solution comprising CO2 in the form of dissolved inorganic carbon (DIC). In many embodiments, the alkalinity of the alkaline aqueous solution is above pH 7 prior to contact with the gaseous stream, however, in some embodiments the alkalinity of the alkalineaqueous solution drops to approach or reach the solution's maximum buffer capacity upon enrichment with CO2. As such, in many embodiments, the pH of the alkaline aqueous solution at any given time during the operation of the system depends on the salinity of the alkaline aqueous solution and the CO2 concentration of the gas stream, as well as relative flow rates of liquids and the gases through the system of many embodiments. Nevertheless, in many embodiments, the pH of the DIC-enriched solution is suitable for microbial activity to occur in the bioreactor. In many embodiments, the pH and or alkalinity of the alkaline aqueous solution and or DIC-enriched solution are monitored during the operation of the system and adjusted as needed to improve performance of the bioreactor.

[0054] In many embodiments, the DIC-enriched solution is next passed into the bioreactor, along with the supply of microbially metabolizable electrons (e.g., H2), such as to feed CO2 to the one or more CO2-reducing microbial cultures of the CO2-reducing compartment. In many embodiments, prior to reaching and contacting the CO2-reducing microbial cultures, the DIC-enriched solution and or the supply of microbially metabolizable electrons are passed through the one or more pre-treatment compartments and or the additional pre-treatment compartment or compartments to remove contaminants potentially harmful to the CO2-reducing microbial cultures (e.g., dissolved O2). In many embodiments, the one or more CO2-reducing microbial cultures within the CO2-reducing compartment then consume the supplied DIC and the microbially metabolizable electrons to produce a volatile bioreactor product, wherein the volatile bioreactor product is a small molecule that is a gas at the compartment temperature and the compartment pressure of the CO2-reducing compartment of the bioreactor. In many embodiments, the volatile bioreactor product is an organic carbon compound selected from the group comprising (but not limited to): CH4 or another hydrocarbon, methanol or another alcohol, and an acid.

[0055] In some embodiments, the bioreactor-afforded effluent comprising the volatile bioreactor product is next passed into the gas-liquid separation unit, in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit, to separate and purify the volatilebioreactor product prior to flowing to the pyrolysis reactor. In many such embodiments, passing the effluent of the bioreactor through the gas-liquid separation unit allows to remove any unwanted volatile contaminants, such as, for example, gaseous H2O, N2, or H2S from the pyrolysis reactor feed, as well as to remove any remaining volatile bioreactor product from the CO2 capture unit liquids and recycle the bioreactor and CO2 capture unit liquids, which, in turn, allows to operate the system at higher flow rates, thus improving efficiency and minimizing the system’s environmental footprint. In some embodiments, the gas-liquid separation unit separates liquids and gases via pressure and temperature adjustments, or via membranes, and or molecular sieve; or any combination thereof. In some embodiments, the volatile bioreactor product is only dehydrated (e.g., by a molecular sieve) after leaving the bioreactor and prior to entering the pyrolysis reactor.

[0056] In many embodiments, the thus microbially produced, volatile bioreactor product is, next, flown into the pyrolysis reactor (optionally, via the gas-liquid separation unit and or via a dehydration unit) as a pyrolysis reactor feed characterized by a bioreactor product concentration. In many embodiments, the bioreactor product concentration is 0.1 to 100 %. In many embodiments, next, the volatile bioreactor product is pyrolyzed in the pyrolysis reactor with or without the help of the pyrolysis catalyst to undergo a pyrolysis to produce the carbon material. In some embodiments, the pyrolysis of the volatile bioreactor product affords additional useful pyrolysis by-products that can be re-cycled or otherwise used in the system and method of many embodiments to improve efficiency and energy balance of the system and method. For example, in many embodiments, especially wherein the volatile bioreactor product is a hydrocarbon, such as, for example, methane, the additional pyrolysis by-product is H2, which can be re-cycled in the system in addition to the supply of metabolizable electrons. In some embodiments, especially wherein the pyrolysis reactor feed also comprises H2O, the additional pyrolysis product is CO, which can also be used within the bioreactor to improve overall yields. In some embodiments, the metabolic heat generated from the bioreactor is recovered and used for another process, such as, for example, electricity generation. In many embodiments, the carbon material obtained via the system and method described herein is amenable to facile extraction from the pyrolysis reactor.

[0057] In many embodiments, the carbon material is any allotrope of crystalline carbon. In many embodiments, the carbon material is a non-biodegradable, crystalline carbon material wherein the carbon material contains homogeneously hybridized carbon at the average oxidation state of around zero, and is mostly devoid of H, 0, N, S or other elements. In many embodiments, the carbon material is fibrous and or fibrous crystalline carbon. In many embodiments, the carbon material is a crystalline carbon material, such as, for example, any form of carbon nanotubes (CNTs). In many embodiments, the carbon material is a valuable carbonaceous matter selected from the group consisting of: single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) with dimensions in the range of 1 -5 nm diameter; multi-walled carbon nanotubes (MWCNTs) with dimensions in the range of 2-50 nm diameter; and carbon fibers with tube diameters larger than 50 nm, but still possessing an aspect ratio of length to diameter of greater than 25; and any combination thereof. In many embodiments, the carbon material is a mixture of carbon nanotubes (CNTs) and or carbon fibers (CFs). In many embodiments, the carbon material is characterized as carbon black, graphitic carbon in the form of sheets.

[0058] In many embodiments, the system also comprises: a liquid reservoir situated between and in fluid communication with the CO2 capture unit and the bioreactor; a gas reservoir situated between and in gas communication the bioreactor and the pyrolysis reactor; and a gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit, or any combination thereof. In many such embodiments, such implements are used to control the system’s processes.

[0059] In many embodiments, the gaseous stream comprising CO2 is an industrial plant emissions stream.

[0060] Currently, the annual rate of anthropogenic CO2 release is between 30-36 Gt / year (see, for example, www.iea.org / reports / global-energy-review-2020 / global- energy-and-co2-emissions-in-2020, the disclosure of which is incorporated herein by reference). Thus, to have any significant impact on the urgently needed climatemitigation, CO2 needs to be captured and stored annually at a Gt scale from existing CO2 sources, such as air and industrial flue gases. Many approaches based on chemical or biological sciences have been proposed in the past and are currently actively pursued as single disciplinary research at different levels within the context of local resources, regulatory settings, and expertise. For example, catalytic conversions by chemical sciences take advantage of high rates, moderate catalytic specificity, and scalable processes at the trade-off of often high (fossil) energy requirements for both catalysis and product separation. On the other hand, life sciences take advantage of high catalytic selectivity and low operating energy requirements, at the trade-off of modest rate and modest scalability. However, to date, the enormous potential of combining and integrating the best of chemical and the best of life sciences for CO2 capture and conversion has not been explored.

[0061] Furthermore, the increased awareness of the need for alternative carbon feedstocks and waste management practices in the chemical industry has led to intensified research for identifying new uses for CO2 sources in industry. CO2 is a potential chemical feedstock if it can be captured and concentrated from the atmosphere or other sources and converted into desired products in a cost-effective manner. Although the thermodynamic stability of CO2 is high, recent developments in chemical synthesis methodologies and naturally occurring or engineered microbial factories have demonstrated the viability of CO2 conversion under mild reaction conditions, including low pressure and low reaction temperatures (< 100 °C). Most importantly, CO2 capture and utilization can lead to a fully sustainable chemical industry with a neutral or possibly even negative carbon footprint. Furthermore, technologies that convert waste CO2 into higher value compounds, such as, for example, carbon nanotubes (CNTs), create financial incentives to reduce CO2 emissions into the atmosphere.

[0062] More specifically, for example, a number of processes reported to date use biologically formed organic carbon compounds as intermediates to form carbon-based polymers from CO2, such as, most notably, photosynthetic processes to convert dilute CO2 to reduced carbon compounds for further processing. However, such processes typically suffer from slow reaction rates, heterogeneous feedstocks, low product yields,and titers; and they produce amorphous “bio-oils,” biofuels, or bioplastics mixed in with biomass, wherein further, often expensive, processing is required to upgrade these products or extract them from the plant / microbial broth to create a value-added product. Nevertheless, examples of producing carbon-based materials from CO2 via biological routes include: pyrolyzing biomass (such as, for example, waste crops or bioreactor waste), biogas pyrolysis to make amorphous or crystalline carbon; and growing algae from CO2, or bacteria from CO2, CH4, CO, CH3OH, or other C1 compounds, wherein the algae or bacteria are engineered to anabolically produce biofuels or bioplastics.

[0063] On the other hand, known processes to produce valuable carbon materials, such as CNTs, typically use fossil feedstocks, such as volatile, short chain hydrocarbons. For example, tested and demonstrated feedstocks for carbon synthesis include methane, ethylene, acetylene, propane, 1 ,3-butadiene, and ethanol (see, for example, Li, A. et al., Proceedings of the Combustion Institute, Volume 33, Issue 2, 2011 , 1843-1850, DOI: https: / / doi.Org / 10.1016 / j.proci.2010.06.037, the disclosure of which is incorporated herein by reference). However, deriving high value or crystalline carbon from CO2, rather than fossil carbon feedstocks or deposits, could mitigate CO2 emissions from critical mineral sourcing. Taking graphite as an example, natural graphite production emits 2-8 kg CO2 / kg graphite, while synthetic graphite production from crude oil emits up to 20 kg CO2 / kg graphite (see, for example, Zhang et al. 2023; Environ. Sci. Technol. 2023, 57, 3402-3414, https: / / doi.org / 10.1021 / acs.est.2c08655, the disclosure of which is incorporated herein by reference). Specific examples of producing carbon-based materials from fossil carbon feedstocks include: graphitization of crude oil, natural gas pyrolysis, and pyrolysis of petroleum byproducts. It should be noted here, that the term “pyrolysis” is used, here and throughout the instant disclosure, as an overarching term to include chemical vapor deposition and chemical vapor infiltration, wherein the fossil carbon compound feedstock is chemically decomposed in the absence of O2 with or without a catalyst into a solid carbon product.

[0064] Furthermore, as another, more specific example, Xie, Z., et al. in CO2 fixation into carbon nanofibres using electrochemical — thermochemical tandem catalysis. Nat Catal 7, 98-109 (2024), the disclosure of which is incorporated herein by reference,describe an electrocatalytic-thermocatalytic tandem process for CO2 conversion to carbon, wherein carbon is carbon nanofiber (CNF). However, Xie’s process relies on a concentrated (100 %) CC feed, while CO2 sources that are emitted at scale and relevant to global warming mitigation typically contain CO2 diluted to concentrations less than 100 % CO2, while the atmospheric concentration of CO2 is 0.04 %. As such, considerable energy is required to concentrate CO2 from typical dilute sources to a pure stream needed for Xie et al.’s or similar methods. In addition, Xie et al. in another work, also considers indirectly sourcing CO2 via anaerobically digester produced biogas, followed by plasma- thermochemically decomposing the biogas into CO and H2, to be next combined with a similar pyrolysis method (Xie, Z., et al. Biogas sequestration to carbon nanofibers via tandem catalytic strategies. Nat. Chem. Eng. 2, 118-129 (2025), https: / / doi.org / 10.1038 / s44286-025-00182-1 , the disclosure of which is incorporated herein by reference). However, such approach is limited and differentiated by reliance on inconsistent biogas production rates and volumes, as well as the need for an additional conversion step prior to pyrolysis.

[0065] In addition, direct biomass or ‘bioresidue’ pyrolysis has also been demonstrated, such as, for example, in Zhang, J., et al. Anaerobic fermentation integrated with pyrolysis for carbon resource recovery from food waste and biogas sludge: Effects of inoculation ratio and pyrolysis temperature, Journal of Environmental Management, Volume 379, 2025, 124879, https: / / doi.Org / 10.1016 / j.jenvman.2025.124879, the disclosure of which is incorporated herein by reference). Still, the yield of carbon material for such demonstrated approaches is inherently below that of the process described in the work, due to the inherent heterogeneity of the hydrocarbon feedstock, previously produced from photosynthesis and / or anaerobic digestion. Moreover, the carbon product of such processes may also be contaminated with other elements, such that it does not achieve a consistent, graphitic structure at comparable temperatures. As a result, the carbon material produced via direct biomass or bioresidue pyrolysis thermally degrades in the presence of air at 300-400°C (rather than 580-600°C). However, ease of degradation reduces such products’ feasibility to serve as a CO2 storage compound, as well as their value as graphitic carbon materials.

[0066] Moreover, Clark, D. S. et al. in U.S. patent application No. 18 / 482,871 (the disclosure of which is incorporated herein by reference) describes a dual bioreactor system for direct capture and bioelectrochemical conversion of CO2 to generate value added molecular carbon products. Here, CO2 is first selectively captured by a specialty solid adsorbent, such as MOF or COF materials, zeolites, amine-functionalized silica, functionalized cellulose, or porous polymers, prior to being released into an enriched CO2- containing gaseous stream that is fed into the dual bioreactor system. However, Clark, D. S. et al. provide no clear instruction for separation of target compounds (including fuel, biopolymer, pharmaceutical, industrial enzyme, commodity chemical or biomass) afforded by the described approach to isolate final, value-added product from the reactor’s microbial broth.

[0067] In addition, Reed, J., et al. in U.S. patent application No. 18 / 560,290 (the disclosure of which is incorporated herein by reference) describes bioreactor designs for high productivity growth of microorganism cultures to produce protein directly from gaseous CO2, as well as to other valuable products such as nutritionals, oils, chemicals, and fuels. Here, again, the disclosure focuses on optimization of the CO2 conversion, without any clear way forward for final product extraction, nor even particular product identity. Moreover, the end product is not a carbon material, but organic carbon compounds that may contain O, N, P, S, and have C / H ratios of < 1 .

[0068] Furthermore, Mets, L. in international patent application No. PCT / US2007 / 071138 (the disclosure of which is incorporated herein by reference) describes a bioreactor for contacting methanogenic archaea culture with gaseous CO2 output of an industrial process, along with H2 gas, to produce methane gas. However, such gas bioprocesses are associated with a number of limitations highlighted in Reed (discussed above), such as, for example, requirement for energy-intensive mixing to achieve high mass transfer rates, excess waste of gaseous feedstocks, and safe handling of potentially flammable or explosive gas mixes.

[0069] Accordingly, this application is directed to embodiments of a system and method relying on a synergistic life science and inorganic chemistry approach for capturing dilute CO2 from waste streams and converting it to a robust and easy to isolateand handle carbon material. In many embodiments, the carbon material is designed to be a practically useful material, while, simultaneously, serving as a semi-permanent CO2 storage approach to avoid CO2 emissions into the atmosphere. More specifically, in many embodiments, the system and method rely on use of energy in the form of electricity or heat, a bioreactor supplied with a gaseous stream comprising waste or atmospheric CO2 via a CO2 capture unit comprising an alkaline aqueous solution for capture of CO2 as DIC, and, separately, supplied with microbially metabolizable electrons, and a pyrolysis reactor, in gas communication, direct or indirect, with the bioreactor, to make the carbon material. In many embodiments, the bioreactor is a microbial bioreactor. In many embodiments, the pyrolysis reactor is a reactor utilizing energy to break molecular bonds with or without help of a pyrolysis catalyst in an 02-free reactor environment. In many embodiments, the carbon material is any allotrope of a crystalline carbon. In many such embodiments, the carbon material comprises carbon nanotubes (CNTs).

[0070] To this end, FIGs. 1A through 1G illustrate the bioreactor and its connectivity with the system of many embodiments. More specifically, in many embodiments, the bioreactor comprises one or more compartments, each characterized by a compartment temperature and a compartment pressure, in fluid communication with each other, wherein each compartment is designed to facilitate a specific step or a bio-conversion of the method and or comprising a single or a mixture of microorganisms. In many embodiments, illustrated for example by FIG. 1A, the bioreactor comprises at least one CO2-reducing compartment designed to reduce CO2 (from the gaseous stream) to a volatile bioreactor product, wherein the CO2-reducing compartment comprises one or more CO2-reducing microbial cultures, altogether capable of reducing CO2 to the volatile bioreactor product.

[0071] For example, in some embodiments, the one or more CO2-reducing microbial cultures comprise one type of a microbe that reduces CO2 to the volatile bioreactor product. However, in some other embodiments, the one or more CO2-reducing microbial cultures comprise two different types of microbes, wherein each type simultaneously reduces CO2 to the volatile bioreactor product. In yet some other embodiments, the one or more CO2-reducing microbial cultures comprise one type of a microbe that partiallyconverts CO2 to an intermediate to the volatile bioreactor product, and another type of a microbe that uptakes the intermediate to the volatile bioreactor product and converts it to the volatile bioreactor product. In still yet some other embodiments, the one or more CO2- reducing microbial cultures comprise additional microbes that do not directly participate in the reduction of CO2 to the volatile bioreactor product, yet are active in another biological process that benefits the activity of the directly CO2-reducing microbial cultures. For example, in some such embodiments, the additional microbes are capable of converting sulfates to sulfides, wherein sulfides react with and, as such, remove contaminant O2 from the microbial medium (wherein, if present even in trace concentrations, O2 can cause oxidative stress to the CO2-reducing microbes), thus improving the activity of the directly CO2-reducing microbial cultures. In many embodiments, the one or more CO2-reducing microbial cultures comprise methanogenic microbial cultures. More specifically, in many embodiments the microbial culture or cultures that enable CO2 reduction to the volatile bioreactor product comprise methanogenic microorganisms that can grow with only CO2 as carbon source. In many such embodiments, the methanogenic microorganisms comprise a single strain or a combination of strains of methanogenic archaea. In some embodiments, the bioreactor comprises one or multiple compartments for chemical processing or filtering steps of the method, wherein such compartments are in fluid communication with and situated before and or after any of the compartments of the bioreactor comprising microbial cultures.

[0072] In addition, in some embodiments, illustrated, for example, in FIGs. 1B and 1C, the bioreactor further comprises one or more pre-treatment compartments connected in series and preceding the CO2-reducing compartment, wherein the one or more pretreatment compartments are designed to remove contaminants that might inhibit or in any other way affect the activity of the CO2-reducing microbial cultures (e.g., CN, CI2, and or O2) from any of the feedstocks entering the bioreactor. In many such embodiments, the one or more pre-treatment compartments comprise a single or a mixture of organisms capable of consuming or neutralizing the contaminants. In some embodiments, the contaminants is O2 and the bioreactor comprises an 02-removing pre-treatment compartment comprising one or more 02-consuming microbial cultures, such as, forexample, hydrogen oxidizing bacteria or yeast. In some other embodiments, the one or more pre-treatment compartments are utilized to hydrate the metabolizable electrons to prevent water loss. In some embodiments, the one or more pre-treatment compartments are utilized to treat the bioreactor’s effluent by, for example, passing ozone through the effluent’s liquid to kill microbes, prior to recirculating the effluent to a CO2 capture unit.

[0073] In many embodiments, the compartment pressure is 1 — 10 atm. However, in some embodiments, the compartment pressure is a moderate pressure of 1 — 1 .5 atm. In many embodiments, the compartment temperature is room temperature or higher temperature compatible with the microorganisms comprised within a compartment and their activities. More specifically, in some such embodiments, the compartment temperature is a temperature suitable for psychrophilic, mesophilic, thermophilic, or hyperthermophilic microbes. In some embodiments, the compartment temperature is a temperature in the range of 20 — 80 °C. In some embodiments, the compartment temperatures is 30°C. In some embodiments, the compartment’s temperatures is 37°C. In some embodiments, the compartment temperature is 65°C.

[0074] In many embodiments, the microorganisms within the compartments of the bioreactor are immobilized on a support, while in some other embodiments, the microorganisms are in solution, while in yet other embodiments, the microorganisms are immobilized on the support and in solution. However, it should be noted here that, in many embodiments, immobilization or another form of cell retention allows for higher chemical turnover by increasing cell density. Accordingly, in many embodiments, the support is a high surface area, hydrophilic, nonbiodegradable solid material that retains microbial cells when a fluid flows over the solid material, while creating conditions for a reaction of interest to occur. In many embodiments, the support comprises a nonbiodegradable material, such as, for example, a material selected from the group consisting of, but not limited to: a high surface area plastic, such as, for example, a polyurethane foam; clay and clay-like pellets; molecular sieve; porous carbon and porous carbon pellets; corrosive-resistant metal, and any combination thereof. In some embodiments, microorganisms are retained via membrane separations.

[0075] In many embodiments the bioreactor is also in fluid communication, directly or indirectly, with a CO2 capture unit comprising an alkaline aqueous solution used to capture and dissolve CO2 (as DIC) from the gaseous stream, and, separately, a supply of microbially metabolizable electrons (FIGs. 1 A through 1G). In many embodiments, the alkaline aqueous solution further comprises trace minerals and salts to enable microbial activity in the bioreactor. In many such embodiments, the trace minerals and mineral salts are selected from the group comprising, but not limited to: chlorides, sodium, sulfates, phosphates, ammonium, nitrates, iron, calcium, magnesium, potassium, cobalt, zinc, selenium, tungsten, and any combination thereof. In some embodiments, the supply of microbially metabolizable electrons is selected from the group comprising, but not limited to: a supply of H2; a supply of CO; a supply of other reduced compounds; a supply of biological cofactors, such as, for example, ferredoxin; and any combination thereof. In some embodiments, the supply of metabolizable electrons is provided via electrolysis in situ within the bioreactor. However, it should be noted that, in many embodiments, the supply of metabolizable electrons is delivered from any convenient source. For example, in the embodiments wherein the supply of metabolizable electrons is the supply of H2, H2 is sourced from any convenient H2 source, including, but not limited to: electrolysis, CH4 pyrolysis, geological H2, H2 evolved as a product from another chemical or biochemical process, and any combination thereof. In some such embodiments, the supply of H2 comprises 100 % H2. However, in some embodiments, the supply of H2 is diluted or contaminated with other gaseous compounds, including, but not limited to: CH4, O2, H2O, CO, H2S, CO2, NH3, N2, HCN, or CI2. As such, in some embodiments, wherein the supply of metabolizable electrons comprises contaminants that might inhibit or otherwise affect activity of the one or more CO2-reducing microbial cultures, additional pre-treatment compartment or compartments are utilized to remove the contaminants from the supply of metabolizable electrons prior to the supply of metabolizable electrons contacting the one or more CO2-reducing microbial cultures. For example, in some embodiments, wherein the supply of metabolizable electrons also comprises an O2 contamination, the additional pre-treatment compartment or compartments are utilized, wherein the additional compartment or compartments comprise one or more 02-consuming microbialcultures, such as, for example, hydrogen oxidizing bacteria or yeast. As another example, in some embodiments, wherein the supply of metabolizable electrons comprises a CO contamination, the additional pre-treatment compartment or compartments are utilized, wherein the additional compartment or compartments comprise a CO-consuming microbial cultures. In some embodiments, wherein the supply of metabolizable electrons comprises multiple undesirable contaminants, a plurality of additional pre-treatment compartments connected in series and preceding the CO2-reducing compartment are utilized as described herein to remove the multiple undesirable contaminants prior to the supply of metabolizable electrons contacting the CO2-reducing microbial cultures.

[0076] In some embodiments, illustrated by FIGs. 1B and 1C, the bioreactor is also in fluid and gas communication with a gas-liquid separation unit, wherein the gas-liquid separation unit is also in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit. In many such embodiments, the gas-liquid separation unit aids in separation and purification of the gaseous and liquid products and by-products of the bioreactor, as well as biomass and other unwanted volatile contaminants (e.g., H2O, N2, H2S, biomass, and other precipitates), and allows for recirculation of the bioreactor liquids. In many embodiments, the gas-liquid separation unit is an implement selected from the groups comprising: a distillation column, a centrifuge, a membrane-based filtration system, and any combination thereof.

[0077] In many embodiments, the system also comprises a liquid reservoir for collection of the DIC-enriched aqueous solution prior to its introduction to the bioreactor, wherein the liquid reservoir is situated between and in fluid communication with the CO2 capture unit and the bioreactor to allow for enhanced control of the CO2-enriched feed, including CO2 solution concentration, to the bioreactor (FIGs. 1D through 1F). In many embodiments, the system also comprises a gas reservoir situated between and in gas communication with the gas-liquid separation unit (or directly bioreactor) and the pyrolysis reactor to allow for enhanced control of the pyrolysis reactor feed from the bioreactor (FIGs. 1D through 1F). In many such embodiments, the addition of such control reservoirs allows for enhanced integration and precise control of the system’s components, such as to enhance the overall performance and efficiency for the instantsystem and method for conversion of CO2 to the carbon material. For example, the addition of the gas reservoir allows for enhanced control over the concentration and flow rate of the volatile bioreactor product in the pyrolysis reactor feed, leading to better control over the carbon material’s morphology. In many embodiments, other parameters allowing to control the system and method described herein include the flow rates of the gaseous stream, the alkaline aqueous solution, the DIC-enriched solution, and the supply of metabolizable electrons. Accordingly, in some embodiments, the solution flow rates for the CO2 capture unit and the bioreactor are the same, while in some other embodiments, the solution flow rates for different components and compartments of the system are separately controlled via, for example, pressure-independent pumps.

[0078] In many embodiments, various other implements, such as, for example, a support or a membrane for cell retention within the CO2-reducing compartment (FIGs. 1E and 1 F); a membrane filter for biomass removal from the bioreactor’s effluent for recycling into the CO2 capture unit (FIGs. 1E and 1F), and or a unit to recover and recycle the bioreactor’s waste heat (FIG. 1F) are added to the system as needed to improve the performance of the system and method. In some embodiments, the bioreactor is set up and used to leverage the metabolic process described in, for example, U.S. Application No. 18 / 990,766 the disclosure of which is incorporated herein by reference.

[0079] Furthermore, FIGs. 1H through 1K illustrate the pyrolysis reactor and its connectivity with the system of many embodiments. More specifically, in many embodiments, the pyrolysis reactor is characterized by a pyrolysis temperature and a pyrolysis pressure. In some embodiments, the pyrolysis reactor comprises plasma (FIG. 11). In many embodiments, the pyrolysis reactor comprises a pyrolysis catalyst that can afford a conversion of a hydrocarbon or alcohol to a carbon and molecular hydrogen (FIG. 1 J). In many such embodiments, the pyrolysis catalyst comprises a transition metal from the first series supported on a metal oxide support. In many embodiments, the transition metal is an element selected from the group comprising: Ni, Co, Fe, and any combination thereof. In many embodiments, the pyrolysis catalyst is an iron-based catalyst. In many embodiments, the pyrolysis temperature is 400 — 1 ,500 °C. In some embodiments, thepyrolysis reactor is set up and operated as described in International Application No. PCT / US2024 / 012455, the disclosure of which is incorporated herein by reference.

[0080] Notably, in many embodiments, the pyrolysis temperature is a temperature sufficient to break C-H and or C-0 bonds of compounds within a feedstock to the pyrolysis reactor in the absence of O2, with or without the help of the pyrolysis catalyst, and to maintain dynamic fluid properties necessary for successful conversion of the feedstock to the carbon material. Accordingly, in some embodiments, utilizing the pyrolysis reactor without the pyrolysis catalyst to obtain the carbon material, such as, for example illustrated in FIG. 1H, requires higher temperatures, as compared to the temperatures required for a pyrolysis with the pyrolysis catalyst. In some embodiments, a combination of plasma and high temperature are utilized within the pyrolysis reactor in the absence of the pyrolysis catalyst. It should also be noted here that it is critically important to maintain an 02-free environment within the pyrolysis reactor to avoid the formation of CC from the feedstock wherein the feedstock comprises CO, hydrocarbon or alcohol. In many embodiments, the pyrolysis pressure is 0 to 30 bar.

[0081] Next, FIGs. 2A through 2C schematically illustrates the system and method for converting low concentrations of CO2 to the carbon material via integrating biological and chemical processes according to many embodiments. Accordingly, in many embodiments, the gaseous stream comprising CO2 (such, for example, emitted CO2 or CO2 from another source) in a CO2 concentration is flown (fed) into the system of many embodiments described herein to produce the carbon material for various applications or CO2 storage. In many embodiments, the CO2 concentration is less than 100 %. In many embodiments, the CO2 concentration is 0.04 to 20 vol. %. In many such embodiments, the CO2 concentration is 5 vol. %. In some embodiments, the gaseous stream also comprises O2 in a O2 concentration. In some such embodiments, the O2 concentration is 0 to 30 %.

[0082] In many embodiments, the gaseous stream comprising CO2 is first contacted by the alkaline aqueous solution within the CO2 capture unit at an ambient temperature and pressure to selectively dissolve and capture CO2, affording a DIC-enriched solution comprising CO2 in the form of dissolved inorganic carbon (DIC). In many embodiments,the alkaline aqueous solution is characterized by a pH in the range of pH 7 to 13. However, in some embodiments, the pH of the alkaline aqueous solution is pH 9-11. In some embodiments, the alkaline aqueous solution is supplemented with non-mineral compounds, such as, for example, aminated organic compounds or carbonic anhydrase, to improve the total CO2 concentration in the solution. It should be noted here that DIC comprises dissolved CO2 in the form of carbonic acid, bicarbonate, or carbonate. As such, in many embodiments, the DIC-enriched solution comprises CO2-derived DIC and is enriched relative to an un-buffered aqueous solution at neutral pH, as well as relative to the CO2 concentration of the gaseous stream. However, it should also be noted, that such concentration enrichment via an alkaline aqueous solution contacting does not necessarily affect (or affects to a lesser extent) other gases that may be present in the gaseous stream along with CO2, such as, for example, O2, wherein dissolution properties of such gases are independent of pH. Further notably, similar selective enrichment will occur for other gaseous components of the gaseous stream that have pH independent dissolution in aqueous solutions. In many embodiments, the alkalinity of the alkaline aqueous solution is above pH 7 prior to contact with the gaseous stream, however, in some embodiments the alkalinity of the alkaline aqueous solution drops to approach or reach the solution's maximum buffer capacity upon enrichment with CO2. As such, in many embodiments, the pH of the alkaline aqueous solution at any given time during the operation of the system depends on the salinity of the alkaline aqueous solution and the CO2 concentration of the gas stream, as well as relative flow rates of liquids and the gases through the system of many embodiments. Nevertheless, in many embodiments, the pH of the DIC-enriched solution is suitable for microbial activity to occur in the bioreactor. In many embodiments, the pH and or alkalinity of the alkaline aqueous solution and or DIC- enriched solution are monitored during the operation of the system and adjusted as needed to improve performance of the bioreactor.

[0083] In many embodiments, the DIC-enriched solution is next passed into the bioreactor, along with the supply of microbially metabolizable electrons (e.g., H2), such as to feed CO2 to the one or more CO2-reducing microbial cultures of the CO2-reducing compartment at the CO2-reducing compartment pressure, such as, for example, 1 — 10atm, and the C02-reducing compartment temperature, such as, for example 20 — 80 °C to enable microbial activity. However, in many embodiments, prior to reaching and contacting the CO2-reducing microbial cultures, the DIC-enriched solution and or the supply of microbially metabolizable electrons are passed through the one or more pretreatment compartments and or the additional pre-treatment compartment or compartments to remove contaminants potentially harmful to the CO2-reducing microbial cultures (e.g., traces of dissolved O2, SOx, NOx, CO, and N2), for example, as shown in FIG. 2B. In many embodiments, the one or more CO2-reducing microbial cultures within the CO2-reducing compartment then consume the supplied DIC and the microbially metabolizable electrons to produce a volatile bioreactor product, wherein the volatile bioreactor product is a small molecule that is a gas at the compartment temperature and the compartment pressure of the CO2-reducing compartment of the bioreactor. In many embodiments, the volatile bioreactor product is an organic carbon compound selected from the group comprising (but not limited to): CH4 or another hydrocarbon, methanol or another alcohol, and an acid. It should be noted here, that the volatility property of the volatile bioreactor product allows for advantageously simpler product separation (as the product evolves from the cell envelope and from the bioreactor’s medium solution) prior to directing the volatile bioreactor product to the pyrolysis reactor.

[0084] In some embodiments, the bioreactor-afforded effluent comprising the volatile bioreactor product is next passed into the gas-liquid separation unit, in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit, to separate and purify the volatile bioreactor product prior to flowing it to the pyrolysis reactor. In many such embodiments, passing the effluent of the bioreactor through the gas-liquid separation unit allows to remove any unwanted volatile contaminants, such as, for example, gaseous H2O, N2, or H2S from the pyrolysis reactor feed, as well as to recycle the bioreactor and CO2 capture unit liquids, which, in turn, allows to operate the system at higher flow rates, thus improving efficiency and minimizing the system’s environmental footprint. In some embodiments, the gas-liquid separation unit separates liquids and gases via pressure and temperature adjustments, or via membranes, and or molecular sieve; or any combinationthereof. In some embodiments, the volatile bioreactor product is only dehydrated (e.g., by a molecular sieve) after leaving the bioreactor and prior to entering the pyrolysis reactor. In many such embodiments, at least the dehydration of the volatile bioreactor product prior to pyrolysis improves the overall yield of carbon production by avoiding competing reactions, such as, for example, steam methane reforming in the case of CH4 pyrolysis.

[0085] In many embodiments, the thus microbially produced, volatile bioreactor product is, next, flown into the pyrolysis reactor (optionally, via the gas-liquid separation unit and or via a dehydration unit) as a pyrolysis reactor feed characterized by a bioreactor product concentration, wherein, in many embodiments, the pyrolysis reactor maintained at the pyrolysis temperature of 400 — 1 ,500 °C and the pyrolysis pressure of 1-30 atmospheres. In many embodiments, the bioreactor product concentration is 0.1 to 100 %. In some embodiments, the pyrolysis reactor is thus supplied with the volatile bioreactor product by more than one bioreactor described herein, as illustrated, for example, by FIG. 2C. In many such embodiments, utilizing a plurality of bioreactors to produce the pyrolysis reactor feed allows for various operational advantages, including a straightforward scale-up of the overall system operation, wherein the individual bioreactors are operated at a smaller scale than the pyrolysis reactor they feed into.

[0086] In many embodiments, next, the volatile bioreactor product is pyrolyzed in the pyrolysis reactor with or without the help of the pyrolysis catalyst to undergo a pyrolysis to produce the carbon material. In some embodiments, the pyrolysis of the volatile bioreactor product affords additional useful pyrolysis by-products that can be re-cycled or otherwise used in the system and method of many embodiments to improve efficiency and energy balance of the system and method. For example, in many embodiments, especially wherein the volatile bioreactor product is a hydrocarbon, such as, for example, methane, the additional pyrolysis by-product is H2, which can be re-cycled in the system in addition to the supply of metabolizable electrons. In some embodiments, especially wherein the pyrolysis reactor feed also comprises H2O, the additional pyrolysis product is CO, which can also be used within the system to improve overall yields. In some embodiments, the metabolic heat generated from the bioreactor is recovered and usedfor another process (e.g., electricity generation). In many such embodiments, recovering the waste heat from the bioreactor improves the energy efficiency of the system, wherein, for example, the recovered heat is used in other parts of the system; and or, as another example, for electricity production. In many embodiments, the carbon material obtained via the system and method described herein is amenable to facile extraction from the pyrolysis reactor. For example, in many embodiments, especially wherein the pyrolysis reactor comprises the pyrolysis catalyst, and the afforded carbon material is crystalline carbon, the carbon material is isolated from the pyrolysis catalyst using known methods for catalyst removal, such as, for example, acid washing, or, as another example, physical dislocation, such as in a fluidized bed set up (as described, for example, in: Behabtu, Natnael, Micah J. Green, and Matteo Pasquali. "Carbon nanotube-based neat fibers." Nano today 3.5-6 (2008): 24-34.; and E. Sun, et al. 2023 DOI: 10.1016 / j.xcrp.2023.101338, the disclosures of which are incorporated herein by reference).

[0087] Accordingly, in many embodiments, especially wherein the pyrolysis reactor comprises the pyrolysis catalyst, the afforded carbon material is a crystalline carbon material such as, for example, shown, along with various characterizations, in FIGs. 3A though 5, wherein the carbon material was obtained according to the instant method from a catalytic pyrolysis of CP as the volatile bioreactor product. In these examples, the crystalline carbon material was easily dislodged from the pyrolysis catalyst (e.g., via acidwashing of the pyrolysis catalyst or physical removal of the carbon material from the pyrolysis catalyst) and collected for storage or further use.

[0088] However, in many embodiments, the carbon material is any allotrope of crystalline carbon. In many embodiments, the carbon material is a non-biodegradable, crystalline carbon material wherein the carbon material contains homogeneously hybridized carbon at the average oxidation state of around zero, and is mostly devoid of H, O, N, S or other elements. In many embodiments, the carbon material is fibrous and or fibrous crystalline carbon. In many embodiments, the carbon material is a crystalline carbon material, such as, for example, any form of carbon nanotubes (CNTs). In many embodiments, the carbon material is a valuable carbonaceous matter selected from thegroup consisting of: single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) with dimensions in the range of 1-5 nm diameter; multiwalled carbon nanotubes (MWCNTs) with dimensions in the range of 2-50 nm diameter; and carbon fibers with tube diameters larger than 50 nm, but still possessing an aspect ratio of length to diameter of greater than 25; and any combination thereof. In many embodiments, the carbon material is a mixture of carbon nanotubes (CNTs) and or carbon fibers (CFs). In many embodiments, the carbon material is characterized as carbon black, graphitic carbon in the form of sheets.

[0089] In addition, notably, in many embodiments, the gaseous stream comprising CO2 is an industrial plant emissions stream. In many embodiments, the CO2 gas in the gaseous stream fed into the system and process described herein is dilute. In some such embodiments, the gaseous stream comprises as little as 5 % CO2, wherein such low CO2 concentration is representative of emissions from natural gas power plants. In some embodiments, the gaseous stream comprises as little as 35 % CO2, wherein such CO2 concentration is representative of emissions from steel manufacturing. In some embodiments, the CO2 concentration in the gaseous stream fed into the system is as low as 0.04 %, representative of the atmosphere’s CO2 concentration. Therefore, the system and method of many embodiments may be used for direct from air CO2 capture and conversion into the carbon material.

[0090] In many embodiments, the pyrolysis catalyst amount and regeneration, the biogas production, and the gas transfer rates between the bioreactor and the pyrolysis reactor are optimized for increasing the production rates and commercial viability of producing the carbon material from dilute CO2 source via the system and method of many embodiments powered by electricity, while also achieving net negative CO2 emissions. More specifically, for example, in many embodiments, the flow rate and concentration of methane produced by the methanogenic microbes within the bioreactor for feeding to the pyrolysis reactor are optimized for carbon production and overall energy efficiency of CO2 conversion to the carbon material.

[0091] Accordingly, the integrated bio-chemical system and method of many embodiments described herein solve several existing challenges that have preventedcoupling of biological and chemical approaches for CO2 capture and storage. For example, as a representative chemical approach, hydrocarbon pyrolysis typically requires high purity feedstock steams at constant flow rates to minimize capital costs and improve overall yields. On the other hand, biological processes, including microbially-assisted CO2 reduction described herein, are typically more variable in turnover rate and product purity, and, therefore, require additional processing steps to be used as intermediates between CO2 reduction and pyrolysis to carbon material. However, the system and method of many embodiments described herein allow to simultaneously solve issues related to the heterogeneity and separation of the volatile bioreactor product. More specifically, due to the selectivity of CO2 conversion by the bioreactor of many embodiments to gaseous reduced carbon products, mere mixing of the gaseous reduced carbon products in an interim gas reservoir between the bioreactor and the pyrolysis reactor facilitates stable operating conditions for pyrolysis to produce the carbon material. Additionally, since the CO2 capture and microbial conversion system is well defined, in many embodiments, the control over the CO2 and metabolizable electron feed rates consistently produces the gaseous reduced carbon compound, such as, for example, CH4, at a predictable rate. Subsequently, in many embodiments, feeding the gaseous reduced carbon compound at the desired rate into the pyrolysis reactor also consistently produces the carbon material. Moreover, the system and method of many embodiments allow for a higher level of control relative to, for example, photosynthesis-mediated processes, wherein the instant system and method selectively absorb CO2 from the gaseous stream and selectively produce only (i.e., pure) the gaseous reduced carbon compound intermediate to feed to the pyrolysis reactor to produce the carbon material.

[0092] In many embodiments, the upcycling process described herein converts waste CO2 into a climate inert, semi-permanent storage carbon material, which could potentially enhance, or even replace, high net CO2 emissions materials across manufacturing and construction industries. In many embodiments, the carbon material, wherein the carbon material is CNTs, is used to make conductive wires, electrodes, and or fibers for implementation in a wide variety of industries, ranging from computer chip manufacturing to construction. It should be noted here, that the carbon of the carbon material is notmicrobially accessible and, therefore, represents a semi-permanent storage material for CO2 sequestration. Therefore, the method and process of many embodiments described herein has a unique potential to be a negative CO2 emissions process if the carbon material is not thermally, electrochemically, or chemically decomposed.DOCTRINE OF EQUIVALENTS

[0093] This description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications. This description will enable others skilled in the art to best utilize and practice the invention in various embodiments and with various modifications as are suited to a particular use. The scope of the invention is defined by the following claims.

Claims

CLAIMS:1 . A system for reduction of CO2 to a carbon material comprising: a bioreactor at least comprising a CCh-reducing compartment, characterized by a compartment temperature and a compartment pressure, wherein the CO2- reducing compartment further comprises one or more CO2-reducing microbial cultures; a pyrolysis reactor, characterized by a pyrolysis temperature and a pyrolysis pressure; and a CO2 capture unit comprising an alkaline aqueous solution; and a supply of metabolizable electrons; wherein the bioreactor is in fluid communication, direct or indirect, with the CO2 capture unit and, separately, in direct fluid communication with the supply of metabolizable electrons; and in gas communication, direct or indirect with the pyrolysis reactor.

2. The system of claim 1 , wherein the one or more CO2-reducing microbial cultures are methanogenic microbial cultures.

3. The system of claim 1 , wherein the bioreactor comprises at least one additional compartment, wherein the at least one additional compartment is a pre-treatment compartment in fluid communication with the CO2-reducing compartment and either the CO2 capture unit or the supply of metabolizable electrons or both, such that the pre-treatment compartment is situated between the CO2-reducing compartment and either the CO2 capture unit or the supply of metabolizable electrons or all three; and wherein the pre-treatment compartment comprises at least one microbial culture capable of consuming or neutralizing contaminants harmful to the one or more CO2- reducing microbial cultures.

4. The system of claim 3, wherein the pre-treatment compartment comprises at least one 02-consuming microbial culture.

5. The system of claim 4, wherein the at least one 02-consuming microbial culture is a microbe selected from the group consisting of: a hydrogen oxidizing bacterium, a yeast, and any combination thereof.

6. The system of claim 1 , wherein the one or more CO2-reducing microbial cultures are immobilized or retained on a support.

7. The system of claim 6, wherein the support comprises a high surface area material selected from the group consisting of: polyurethane foam, clay and clay-like pellets, carbon, metal, molecular sieve and any combination thereof.

8. The system of claim 1 , wherein the supply of metabolizable electrons is a supply of H2.

9. The system of claim 1 , wherein the compartment pressure is 1 — 10 atm.

10. The system of claim 1 , wherein the compartment temperature is room temperature or higher temperature compatible with the one or more CO2-reducing microbial cultures and their activity.

11. The system of claim 10, wherein the compartment temperature is a temperature suitable for growth of psychrophilic, mesophilic, thermophilic or hyperthermophilic microorganisms.

12. The system of claim 1 , wherein the pyrolysis reactor comprises a pyrolysis catalyst.

13. The system of claim 12, wherein the pyrolysis catalyst comprises a transition metal from the first series supported on a metal oxide support.

14. The system of claim 13, wherein, the transition metal is an element selected from the group consisting of: Ni, Co, Fe, and any combination thereof.

15. The system of claim 1 , wherein the pyrolysis temperature is 400 — 1 ,500 °C.

16. The system of claim 1 , wherein the system further comprises a liquid reservoir situated between and in fluid communication with the CO2 capture unit and the bioreactor.

17. The system of claim 1 , wherein the system further comprises a gas reservoir situated between and in gas communication the bioreactor and the pyrolysis reactor.

18. The system of claim 1 , wherein the system further comprises a gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit.

19. The system of claim 1 , wherein the system further comprises a liquid reservoir situated between and in fluid communication with the CO2 capture unit and the bioreactor; a gas reservoir situated between and in gas communication the bioreactor and the pyrolysis reactor; and a gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit, or any combination thereof.

20. A method for reduction of CO2 to a carbon material comprising: providing a system comprising: a bioreactor at least comprising a CO2-reducing compartment, characterized by a compartment temperature and a compartment pressure, wherein the CO2-reducing compartment further comprises one or more CO2-reducing microbial cultures; a pyrolysis reactor, characterized by a pyrolysis temperature and a pyrolysis pressure; and a CO2 capture unit comprising an alkaline aqueous solution; and a supply of metabolizable electrons; wherein the bioreactor is in fluid communication, direct or indirect, with the CO2 capture unit and, separately, in direct fluid communication with the supply of metabolizable electrons; and in gas communication, direct or indirect with the pyrolysis reactor; flowing a gaseous stream comprising CO2 in a CO2 concentration through the CO2 capture unit to dissolve and capture CO2, thus affording a DIC-enriched solution; flowing the DIC-enriched solution into the bioreactor, while also flowing the supply of metabolizable electrons into bioreactor; allowing the one or more CO2-reducing microbial cultures to consume CO2 from the DIC-enriched solution such as to produce a volatile bioreactor product; collecting the volatile bioreactor product as a gas; flowing the volatile bioreactor product into the pyrolysis reactor; and allowing the volatile bioreactor product to undergo pyrolysis to obtain the carbon material and additional gaseous co-products.

21. The method of claim 20, wherein the bioreactor comprises at least one additional compartment, wherein the at least one additional compartment is a pre-treatment compartment in fluid communication with the CO2-reducing compartment and either the CO2 capture unit or the supply of metabolizable electrons or both, such that the pre-treatment compartment is situated between the CO2-reducing compartment and either the CO2 capture unit or the supply of metabolizable electrons or all three; and wherein the pre-treatment compartment comprises at least one microbial culture capable of consuming or neutralizing contaminants harmful to the one or more CO2- reducing microbial cultures.

22. The method of claim 21 , wherein the pre-treatment compartment comprises at least one 02-consuming microbial culture.

23. The method of claim 20, wherein the volatile bioreactor product is a molecule, volatile at the compartment temperature and the compartment pressure, selected from the group comprising: CF or another hydrocarbon, methanol or another alcohol, and an acid.

24. The method of claim 23, wherein the volatile bioreactor product is CH4.

25. The method of claim 20, wherein the supply of metabolizable electrons is a supply of H2.

26. The method of claim 25, wherein the supply of H2 is characterized by an H2 concentration of 0 to 100 %.

27. The method of claim 20, wherein the carbon material is any allotrope of crystalline carbon.

28. The method of claim 27, wherein the carbon material comprises any form of carbon nanotubes.

29. The method of claim 20, wherein the gaseous stream is an industrial plant emissions stream.

30. The method of claim 20, wherein the CO2 concentration is 0.04 to 9 %.

31. The method of claim 20, wherein the CO2 concentration is 5 %.

32. The method of claim 20, wherein the system further comprises a liquid reservoir for collecting the DIC-enriched solution prior to its introduction to the bioreactor, wherein the liquid reservoir is situated between and in fluid communication with the CO2 capture unit and the bioreactor; and further wherein the liquid reservoir is used to control the flowing the DIC-enriched solution into the bioreactor.

33. The method of claim 20, wherein the system further comprises a gas reservoir for collecting the volatile bioreactor product prior to its introduction to the pyrolysis reactor, wherein the gas reservoir is situated between and in gas communication with the bioreactor and the pyrolysis reactor; and further wherein the gas reservoir is used to control the flowing the volatile bioreactor product into the pyrolysis reactor.

34. The method of claim 20, wherein the system further comprises a gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit.

35. The method of claim 20, wherein the system further comprises: a liquid reservoir situated between and in fluid communication with the CO2 capture unit and the bioreactor; a gas reservoir situated between and in gas communication the bioreactor and the pyrolysis reactor; and a gas-liquid separation unit capable of separating gases and liquids and situated so that it is in fluid and gas communication with the bioreactor, in gas communication with the pyrolysis reactor, and in liquid communication with the CO2 capture unit, or any combination thereof; and further wherein the liquid reservoir, the gas reservoir, and the gas-liquid separation unit are used to control the system’s processes.

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