Purified products and process therefore

Abstract

The disclosure is directed to an apparatus and method for recovering ethanol from a fermentation broth. The fermentation broth may comprise a fermentation product such as ethanol, microbial biomass, and at least one impurity. The method comprises separating at least microbial biomass from the fermentation broth to generate a process stream and removing at least one of the impurities from the process stream. The at least one impurity is removed from the microbial biomass depleted process stream by (1) contacting with at least one carbon bed, copper-containing adsorbent bed, silver-containing adsorbent bed, metal copper, and or metal silver; (2) distilling with a basic or acidic chemical compound; and or (3) adding a chemical compound to react with sulfur-containing compounds followed by distilling. The purified fermentation product is recovered.

Description

PURIFIED PRODUCTS AND PROCESS THEREFORE CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 654,472 filed May 31, 2024, the entirety of which is incorporated herein by reference. FIELD

[0002] This disclosure relates to a composition comprising a purified product from a fermentation broth and a method for recovering the at least one purified fermentation product from a fermentation broth. In particular, the disclosure relates to a composition comprising the purified fermentation product and at least one fragrance component. The disclosure further relates to the a) use of an adsorbent and or b) distillation with a basic or acidic chemical compound, and or c) chemical addition prior to or during distillation to purify and recover at least one product from a fermentation broth, where the fermentation broth contains microbial biomass, a fermentation product such as ethanol, and impurities. BACKGROUND

[0003] Mitigation of impending climate change requires drastic changes in manufacturing and greater reliance on biotechnology. Sustainable sources of fuels and chemicals are currently insufficient to significantly displace dependence on fossil carbon. Biotechnology harnesses the power of biology to create new products in a way that improves the quality of life and the environment, Gas fermentation is emerging as a powerful biotechnological advancement as an alternative platform for the biological fixation of such gases such as CH4, CO, CO2, and / or H2into sustainable fuels and chemicals. In particular, gas fermentation technology can utilize a wide range of feedstocks including gasified carbon-containing matter such as municipal solid waste or agricultural waste, or industrial waste gases such as off-gases from steel manufacturing, petroleum refineries, and petrochemical processes to produce ethanol, aviation fuel, chemicals, and a variety of other products. Gas fermentation alone could displace 30% of crude oil use and reduce global CO2emissions by 10%. As with any disruptive technology, many technical challenges must be overcome before this potential is fully achieved. The science of scale-up production and the reduction of obstacles for continued commercialization of gas fermentation are advanced by this disclosure.

[0004] Carbon dioxide (CO2) accounts for about 76% of global greenhouse gas emissions from human activities, with methane (16%), nitrous oxide (6%), and fluorinated gases (2%) accounting for the balance (the United States Environmental Protection Agency). The majorityof CO2 comes from the burning of fossil fuels to produce energy, although industrial and forestry practices also emit CO2into the atmosphere. Reduction of greenhouse gas emissions, particularly CO2, is critical to halting the progression of global warming and the accompanying shifts in climate and weather.

[0005] It has long been recognized that catalytic processes, such as the Fischer-Tropsch process, may be used to convert gases containing carbon dioxide (CO2), carbon monoxide (CO), and / or hydrogen (H2), such as industrial waste gas or syngas, into a variety of fuels and chemicals. Recently, however, gas fermentation has emerged as an alternative platform for the biological fixation of such gases. In particular, C1-fixing microorganisms have been demonstrated to convert gases containing CO2, CO, and / or H2into products such as ethanol and isopropanol.

[0006] Typically, products produced through either Fischer-Tropsch and / or gas fermentation are separated through conventional distillation. The distillation process is based on the difference in the volatility, i.e., the difference in boiling point, of the components to be separated. By products produced and therefore present must also be separated from the product(s). However, for some end uses, simple conventional distillation without more has been shown to be unable to effectively separate the desired product from the solution at a high enough purity level.

[0007] For example, in gas fermentation using C1-fixing microorganisms, when ethanol is the desired products, by-products comprise methanol, acetal, ethyl acetate, acetaldehyde, diethoxyethers, organic sulfides, and possibly some sulfur containing compounds such as mercaptans, thioesters, thioacids, C2 to C12 esters, and aromatics such as toluene, xylenes, and ethylbenzene and any combination thereof. Further Depending upon the end use of the ethanol, one or more of these by-products or impurities may need to be removed to be below specified levels. To achieve a high purity product ethanol particular separation steps are desirable.

[0008] Accordingly, there remains a need for a system that is effective at separating impurities, which may be byproduct compounds, from a fermentation broth or fermentation product such as ethanol to achieve a high purity fermentation product. The fermentation process may be a gas fermentation process.

[0009] The discussion herein is provided to aid in understanding the disclosure and is not admitted to describe or constitute prior art thereto.BRIEF SUMMARY Described herein are systems and methods for purifying fermentation broth. In a first aspect, the present disclosure relates to methods for purifying a fermentation product from a fermentation broth comprising microbial biomass, at least one fermentation product, and at least one impurity, the method comprising: (a) separating at least microbial biomass from the fermentation broth to generate a microbial biomass depleted process stream; (b) removing, at least one impurity from the microbial biomass depleted process stream by passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, silver-containing adsorbent bed, copper metal, and or silver metal; distilling with a basic or acidic chemical compound; and or adding a chemical compound to react with sulfur- containing compounds followed by distilling; and (c) recovering a purified fermentation product.

[0010] In some embodiments, the distilling is conducted with a basic or acidic chemical compound and comprises adding the basic or acidic chemical compound at an upper one-third of a distillation column, into a reflux line, and or into a reflux pot.

[0011] In some embodiments, the at least one carbon bed comprises a graphite carbon, a non- graphite carbon, or any combination thereof.

[0012] In some embodiments, the at least one carbon bed comprises activated carbon or activated charcoal.

[0013] In some embodiments, the fermentation product is generated by gas fermentation of a C1 containing substrate.

[0014] In some embodiments, the fermentation product is generated by gas fermentation of a substrate comprising carbon monoxide or carbon dioxide or hydrogen or any combination thereof using a C1-fixing microorganism.

[0015] In some embodiments, the C1-fixing microorganism is an aerobic bacterium or an anerobic bacterium.

[0016] In some embodiments, both the passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, and or silver-containing adsorbent bed and the distilling with a basic or acidic chemical compound are conducted.

[0017] In some embodiments, the passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, and or silver-containing adsorbent bed is conducted prior to the distilling with a basic or acidic chemical compound.

[0018] In some embodiments, the method further comprises dehydrating the purified fermentation product.

[0019] In some embodiments, the fermentation product is selected from ethylene, ethanol, propane, acetate, 1-butanol, butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), acetone, isopropanol, a lipid, 3-hydroxypropionate (3-HP), a terpene, isoprene, a fatty acid, 2-butanol, 1,2-propanediol, 1propanol, 1hexanol, 1octanol, chorismate- derived products, 3hydroxybutyrate, 1,3butanediol, 2-hydroxyisobutyrate or 2- hydroxyisobutyric acid, isobutylene, adipic acid, 1,3hexanediol, 3-methyl-2-butanol, 2-buten- 1-ol, isovalerate, isoamyl alcohol, and monoethylene glycol, or any combination thereof. Another aspect of the disclosure is a composition comprising: a purified fermentation product; and a fragrance component selected from agrumen, aliphatic aldehydes, amber, ambergris, ambrette, amyris, benzoin, bergamot, black pepper, calone, cashmeran, castoreum, citron, civet, clary sage, coumarin, frangipani, frankincense, galbanum, guaiac wood, hedione, heliotrope, indole, iso e super, jasmone, labdanum, lavender, lily of the valley, magnolia, mandarin, monoi, muguet, musk, myrrh, narcissus, neroli, oakmoss, opopanax, orris, osmanthus, oud, patchouli, rose, rose de mai, sandalwood, tonka bean, vanilla, vetiver, ylang-ylang, and any combination thereof; wherein the purified fermentation product is recovered from a fermentation broth comprising microbial biomass, at least one fermentation product, and at least one impurity, by separating at least microbial biomass from the fermentation broth to generate a microbial biomass-depleted process stream and removing the at least one impurity from the microbial biomass-depleted process stream by passing the microbial biomass-depleted stream over carbon bed, copper-containing adsorbent bed, silver- containing adsorbent bed, copper metal, and or silver metal; distillation with a basic or acidic chemical compound; and or adding a chemical compound to react with sulfur-containing compounds followed by distilling.

[0020] In some embodiments, the fermentation broth is generated in a gas fermentation process.

[0021] In some embodiments, the distilling with a basic or acidic chemical compound comprises adding the basic or acidic chemical compound at an upper one-third of a distillation column, into a reflux line, and or into a reflux pot.

[0022] In some embodiments, the at least one carbon bed comprises a graphite carbon, a non- graphite carbon, or any combination thereof.

[0023] In some embodiments, the at least one carbon bed comprises activated carbon or activated charcoal.

[0024] In some embodiments, the fermentation product is generated by gas fermentation of a C1 containing substrate.

[0025] In some embodiments, the fermentation product is generated by gas fermentation of a substrate comprising carbon monoxide or carbon dioxide or hydrogen or any combination thereof using a C1-fixing microorganism.

[0026] In some embodiments, the C1-fixing microorganism is an aerobic bacterium or an anerobic bacterium.

[0027] In some embodiments, both the passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, and or silver-containing adsorbent bed, and the distilling with a basic or acidic chemical compound are conducted.

[0028] In some embodiments, the passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, and or silver-containing adsorbent bed is conducted prior to the distilling with a basic or acidic chemical compound.

[0029] In some embodiments, the purified fermentation product is a dehydrated purified fermentation product.

[0030] In some embodiments, the purified fermentation product is selected from ethylene, ethanol, propane, acetate, 1-butanol, butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), acetone, isopropanol, a lipid, 3-hydroxypropionate (3-HP), a terpene, isoprene, a fatty acid, 2-butanol, 1,2-propanediol, 1propanol, 1hexanol, 1octanol, chorismate-derived products, 3hydroxybutyrate, 1,3butanediol, 2-hydroxyisobutyrate or 2- hydroxyisobutyric acid, isobutylene, adipic acid, 1,3hexanediol, 3-methyl-2-butanol, 2-buten- 1-ol, isovalerate, isoamyl alcohol, and monoethylene glycol, or any combination thereof.

[0031] In some embodiments, the composition is selected from fragrances, personal care products, cosmetics, and home care products.

[0032] In some embodiments, the composition is selected from perfume, cologne, eau de Toilette, Eau de Parfum, aftershave, hair care products, hair dye, hair shampoo, hair conditioner, hair spray, shower gel, soap, body lotion, body spray, mouth wash, deodorants, antiperspirants, laundry detergents, fabric softeners, fabric dye, dryer sheets, room fresheners, air fresheners, carpet fresheners, essential oils, cleaning products, polishing products, scouring or abrasive products, toiletries, sanitary preparations, tissue, nail products, diapers, bandages, sunscreen, nourishing cream, hand cream, lipstick, lip gloss, sun oil, massage cream, cleansingcream, facial pack, serums for cosmetic purposes, cocoa butter, skin care product, retinol cream, muscle gel, body paint, cooling spray, cold cream, pomade, cleaning products, dishwashing liquid, hand sanitizers, sanitizing gels, sanitizing wipes, shampoos other than hair shampoo household products, pet care products, pet shampoo, pet cleaning, animal deterrents, candles, car care products, industrial fragrances, and fragrance oils.

[0033] In another aspect the disclosure relates to an apparatus for separating ethanol from a fermentation broth comprising microbial biomass, ethanol, at least one hydrocarbon and at least one ester, the apparatus comprising: (a) a first separation unit, in fluid communication with a bioreactor, configured to separate at least microbial biomass from the fermentation broth and generate a process stream comprising ethanol, at least one impurity; (b) at least one second separation unit, in fluid communication with the first separation unit, selected from: an adsorptive separation unit comparing a carbon adsorbent, a copper containing adsorbent, and or a silver containing adsorbent; a distillation separation unit equipped to add a basic or acidic chemical to the distillation; and a chemical addition unit followed by at least two distillation columns; and (c) a purified ethanol conduit in fluid communication with the second separation unit.

[0034] It is an object of the present invention to provide one or more process which goes at least some way towards overcoming or ameliorating at least one of the disadvantages of the prior art. This object, and any other objectives or advantages or the like referred to herein or taken from this description, are to be read disjunctively and with the alternative object of to at least provide the public with a useful choice. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following detailed description is merely exemplary in nature and is not intended to limit the various embodiments or the application and uses thereof. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. The Figures have been simplified by the deletion of a large number of apparatuses customarily employed in a process of this nature which are not specifically required to illustrate the performance of the invention. Furthermore, the illustration of the process of this disclosure in the embodiment of a specific drawing is not intended to limit the invention to specific embodiments. Some embodiments may be described by reference to the process configuration shown in the figures, which relate to both apparatus and methods to carry out the disclosure. Any reference to method includes reference to an apparatus unit or equipment that is suitable to carry out the step, and vice versa.

[0036] FIG. 1 shows a simplified diagram of alternative embodiments of the disclosure employing separation steps, and particularly shows different separation techniques and different applications of the separation techniques and different orders of the separation techniques.

[0037] FIG.2A and FIG.2B are schematic process flow diagrams showing two embodiments of the disclosure.

[0038] FIG.3 is a schematic process flow diagram showing an embodiment of the disclosure employing two separation techniques in series in accordance with one embodiment of the disclosure.

[0039] FIG.4 is a schematic process flow diagram showing an embodiment of the disclosure employing two separation techniques in series in accordance with one embodiment of the disclosure. The order of the two separation techniques is reversed as compared to FIG.3.

[0040] FIG 5. is a schematic process flow diagram corresponding to an embodiment of the invention. DETAILED DESCRIPTION

[0041] The disclosure relates to a method for recovering product from a fermentation broth comprising microbial biomass, product, by-products, and impurities. The method allows for purification of the product for uses that require high purity product. For ease of understanding, the product will be described herein as ethanol. The disclosure relates to a composition comprising the purified fermentation product and another component. The disclosure also relates to a composition comprising the purified fermentation product and a fragrance component. The composition may be, for example, a personal care product, a fragrance, a cosmetic, and or a home care product. Examples of products include, among others, perfume, cologne, eau de Toilette, Eau de Parfum, aftershave, hair care products, hair dye, hair shampoo, hair conditioner, hair spray, shower gel, soap, body lotion, body spray, mouth wash, deodorants, antiperspirants, laundry detergents, fabric softeners, fabric dye, dryer sheets, room fresheners, air fresheners, carpet fresheners, essential oils, cleaning products, polishing products, scouring or abrasive products, toiletries, sanitary preparations, tissue, nail products, diapers, bandages, sunscreen, nourishing cream, hand cream, lipstick, lip gloss, sun oil, massage cream, cleansing cream, facial pack, serums for cosmetic purposes, cocoa butter, skin care product, retinol cream, muscle gel, body paint, cooling spray, cold cream, pomade, cleaning products, dishwashing liquid, hand sanitizers, sanitizing gels, sanitizing wipes, shampoos other than hair shampoo, household products, pet care products, pet shampoo, petcleaning, animal deterrents, candles, car care products, industrial fragrances, and fragrance oils. Air fresheners may include, among others, scented disks, powders, liquid sprays and odor neutralizers.

[0042] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0043] Technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art, unless otherwise defined. Unless otherwise specified, materials and / or methodologies known to those of ordinary skill in the art can be utilized in carrying out the methods described herein, based on the guidance provided herein.

[0044] As used herein, the singular terms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Reference to an object in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.”

[0045] As used herein, the terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to”) unless otherwise noted.

[0046] As used herein, “about” when used with a numerical value means the numerical value stated as well as plus or minus 10% of the numerical value. For example, “about 10” should be understood as both “10” and “9-11.”

[0047] Also as used herein, “and / or” refers to and encompasses any and all possible combinations of one or more of the associated listed items, as well as the lack of combinations when interpreted in the alternative (“or”).

[0048] The term “acid” as used herein includes both carboxylic acids and the associated carboxylate anion, such as the mixture of free acetic acid and acetate present in a fermentation broth as described herein. The ratio of molecular acid to carboxylate in the fermentation broth is dependent upon the pH of the system. In addition, the term “acetate” includes both acetate salt alone and a mixture of molecular or free acetic acid and acetate salt, such as the mixture of acetate salt and free acetic acid present in a fermentation broth as described herein.

[0049] The term “carbon capture” as used herein refers to the fixation and utilization of carbon including carbon from CO2, CO, and / or CH4from a stream comprising CO2, CO, and / or CH4and converting the CO2, CO, and / or CH4 into useful products.

[0050] The term “substrate comprising carbon monoxide” and like terms should be understood to include any substrate in which carbon monoxide is available to one or more strains of bacteria for growth and / or fermentation, for example.

[0051] The term “gaseous substrates comprising carbon monoxide” includes any gas which contains carbon monoxide. The gaseous substrate will typically contain a significant proportion of CO, preferably at least about 5% to about 100% CO by volume.

[0052] The term “C1 carbon” and like terms should be understood to refer to carbon sources that are suitable for use by a microorganism, particularly those of the gas fermentation process disclosed herein. C1 carbon may include, but should not be limited to, carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4), methanol (CH3OH), and formate (HCOOH).

[0053] The term “substrate comprising carbon dioxide” and like terms should be understood to include any substrate in which carbon dioxide is available to one or more strains of bacteria for growth and / or fermentation, for example.

[0054] The term “gaseous substrates comprising carbon dioxide” includes any gas which contains carbon dioxide. The gaseous substrate will typically contain a significant proportion of CO2, preferably at least about 5% to about 100% CO2 by volume.

[0055] The term “bioreactor” includes a fermentation device consisting of one or more vessels and / or towers or piping arrangements, which includes the continuous stirred tank reactor (CSTR), immobilized cell reactor (ICR), trickle bed reactor (TBR), bubble column, gas lift fermenter, membrane reactor such as hollow fiber membrane bioreactor (HFMBR), static mixer, or other vessel or other device suitable for gas-liquid contact.

[0056] The term “co-substrate” refers to a substance that, while not necessarily being the primary energy and material source for product synthesis, can be utilized for product synthesis when added to another substrate, such as the primary substrate.

[0057] The term “directly”, as used in relation to the passing of industrial off or gases to a bioreactor, is used to mean that no or minimal processing or treatment steps, such as cooling and particulate removal are performed on the gases prior to them entering the bioreactor (note: an oxygen removal step may be required for anaerobic fermentation).

[0058] The terms “fermenting,” “fermentation process,” “fermentation reaction,” and like terms as used herein, are intended to encompass both the growth phase and product biosynthesis phase of the process. As is described further herein, in some embodiments the bioreactor may comprise a primary bioreactor and a secondary bioreactor.

[0059] The term “nutrient medium” as used herein should be understood as the solution added to the fermentation broth containing nutrients and other components appropriate for the growth of the microorganism culture.

[0060] The terms “primary bioreactor” or “first reactor” as used herein this term is intended to encompass one or more reactors that may be connected in series or parallel with a secondary bioreactor. The primary bioreactors generally use anaerobic or aerobic fermentation to produce a product (e.g., ethylene, ethanol, acetate, etc.) from a gaseous substrate.

[0061] The terms “secondary bioreactor” or “second reactor” as used herein are intended to encompass any number of further bioreactors that may be connected in series or in parallel with the primary bioreactors. Any one or more of these further bioreactors may also be connected to a further separator.

[0062] The term “stream” is used to refer to a flow of material into, through and away from one or more stages of a process, for example, the material that is fed to a bioreactor. The composition of the stream may vary as it passes through particular stages. For example, as a stream passes through the bioreactor.

[0063] The terms “feedstock” when used in the context of the stream flowing into a gas fermentation bioreactor (i.e., gas fermenter) or “gas fermentation feedstock” should be understood to encompass any material (solid, liquid, or gas) or stream that can provide a substrate and / or C1-carbon source to a gas fermenter or bioreactor either directly or after processing of the feedstock.

[0064] The term “waste gas” or “waste gas stream” may be used to refer to any gas stream that is either emitted directly, flared with no additional value capture, or combusted for energy recovery purposes.

[0065] The terms “synthesis gas” or “syngas” refers to a gaseous mixture that contains at least one carbon source, such as carbon monoxide (CO), carbon dioxide (CO2), or any combination thereof, and, optionally, hydrogen (H2) that can used as a feedstock for the disclosed gas fermentation processes and can be produced from a wide range of carbonaceous material, both solid and liquid.

[0066] The term “ethanol” is meant to include ethanol as a defined chemical with a known formula (CH3CH2OH) and an ethanol solution containing ethanol and impurities. Similarly, the term “fermentation product” or “product”, is meant to include the specific chemical compound and a solution containing the specific chemical compound which also contains impurities.

[0067] The fermentation product, exemplified herein as ethanol, is produced in a gas fermentation system using a biological catalyst and exits one or more bioreactors in series or in parallel as part of a fermentation broth. The fermentation broth comprises microbial biomass,ethanol, and impurities which may be by-products such as methanol, ethyl acetate, at least one thiol, at least one compound having 3 or more carbon atoms, blackberry thiophene, esters, sulfides, disulfides, trisulfides, aromatics, and or 1,4-dioxane. The fermentation broth may further comprise acetaldehyde. The fermentation broth may further comprise at least one aldehyde. The fermentation broth may additionally comprise other impurities.

[0068] The substrate and / or C1-carbon source for the gas fermentation process may be a waste gas obtained as a byproduct of an industrial process or from another source, such as automobile exhaust fumes, biogas, or landfill gas or from electrolysis. The substrate and / or C1-carbon source may be syngas generated by pyrolysis, torrefaction, or gasification. In other words, waste material may be recycled by pyrolysis, torrefaction, or gasification to generate syngas which is used as the substrate and / or C1-carbon source. In other embodiments, the substrate and / or C1 carbon source may be CO2from, for example, direct air capture. In addition to the substrate and or C1 carbon source, hydrogen may be supplied to the gas fermentation.

[0069] Hydrogen may be from any source, although green hydrogen from electrolysis is a desirable embodiment. In some embodiments, the hydrogen in the stream comprises hydrogen selected from green hydrogen, blue hydrogen, grey hydrogen, pink hydrogen, red hydrogen, turquoise hydrogen, yellow hydrogen, white hydrogen, brown hydrogen, black hydrogen, or any combination thereof. The term “green hydrogen” refers to hydrogen generated from electrolysis using electricity from renewable sources to split water into hydrogen and oxygen without generating CO2. The term “blue hydrogen” refers to hydrogen primarily generated from steam reforming of natural gas thereby producing hydrogen and carbon dioxide. Blue hydrogen refers to hydrogen that combines grey hydrogen production with CO2 capture technology to minimize emissions. The term “grey hydrogen” refers to hydrogen derived from natural gas and is primarily generated from steam reforming of natural gas to generate hydrogen and carbon dioxide. The carbon dioxide is not captured and stored / sequestered. The terms “pink hydrogen” and “red hydrogen” refer to hydrogen generated through electrolysis where the electricity is from nuclear energy. The term “turquoise hydrogen” refers to hydrogen generated by methane pyrolysis producing solid carbon and hydrogen with no CO2 production. The term “yellow hydrogen” refers to hydrogen generated by electrolysis where the electricity is from solar power. The term “white hydrogen” refers to hydrogen that is naturally occurring hydrogen such as that found in underground deposits. The terms “brown hydrogen” or “black hydrogen” refer to hydrogen that is produced from black or brown coal. This process releases high amounts of CO2.

[0070] In certain embodiments, substrate and / or C1-carbon source is a waste or underutilized gas from an industrial process, which, for example, may be selected from ferrous metal products manufacturing, such as a steel mill manufacturing, non-ferrous products manufacturing, petroleum refining, electric power production, carbon black production, paper and pulp manufacturing, ammonia production, methanol production, coke manufacturing, or any combination thereof. In these embodiments, the substrate and / or C1-carbon source may be captured from the industrial process before it is emitted into the atmosphere, using any known method.

[0071] As stated, the substrate and or C1 carbon source may be already in the form of a gas (e.g., a waste gas or underutilized gas), or a solid or liquid material may be first processed in a preliminary step of the overall gas fermentation process to generate synthesis gas known as syngas which in turn is provided to the bioreactor of the gas fermentation system. The preliminary step to generate syngas may involve reforming, partial oxidation, plasma, and or gasification processes. Examples of gasification processes include gasification of coal, gasification of refinery residues, gasification of petroleum coke, gasification of biomass, gasification of lignocellulosic material, gasification of waste wood, gasification of black liquor, gasification of municipal solid waste, gasification of municipal liquid waste, gasification of industrial solid waste, gasification of industrial liquid waste, gasification of refuse derived fuel, gasification of sewerage, gasification of sewerage sludge, gasification of sludge from wastewater treatment, gasification of landfill gas, gasification of biogas such as when biogas is added to enhance gasification of another material, gasification of tires, pieces of tires, and or components of tires, and gasification of tires, pieces of tires, and or components of tires combined with an organic material. Examples of reforming processes include, steam methane reforming, steam naphtha reforming, reforming of natural gas, reforming of biogas, reforming of landfill gas, reforming of coke oven gas, reforming of pyrolysis off-gas, reforming of ethylene production off-gas, naphtha reforming, and dry methane reforming. Examples of partial oxidation processes include thermal and catalytic partial oxidation processes, catalytic partial oxidation of natural gas, partial oxidation of hydrocarbons, partial oxidation of biogas, partial oxidation of landfill gas, or partial oxidation of pyrolysis off-gas. Examples of municipal solid waste include tires, plastics, refuse derived fuel, and fibers such as in shoes, apparel, and textiles. Municipal solid waste may be simply landfill-type waste and may be sorted or unsorted. Examples of tires include end of life tires, defective tires, surplus tires, and tire scraps. Examples of biomass may include lignocellulosic material and microbial biomass.Lignocellulosic material may include agriculture waste and forest waste. In another embodiment, the substrate and / or C1 carbon source is derived from the gasification of tires, pieces of tires, and or components of tires, optionally in combination with organic material, followed by gas fermentation may be employed to convert end of life tires, defective tires, and or tire scraps into valuable products. The gasification and gas fermentation process may be co- located with and integrated with chemical production processes used to generate chemicals and intermediates for use in the generation of new tires.

[0072] The substrate and / or C1 carbon source may be a gas stream comprising methane. Such a methane containing gas may be obtained from fossil methane emissions such as during fracking or other hydrocarbon well stimulation processes or from coalbeds, or may be obtained from wastewater treatment, livestock, agriculture, and municipal solid waste landfills. It is also envisioned that the methane may be burned or employed as a feed in a fuel cell to produce electricity or heat, and the C1 by-products may be used as the substrate or carbon source.

[0073] Fermentation product may be one or more products. For instance, the product(s) may include, among others, ethanol, isopropanol, monoethylene glycol, sulfuric acid, propylene, sodium hydroxide, sodium carbonate, ammonia, benzene, acetic acid, ethylene, ethylene oxide, formaldehyde, methanol, acetate, 1-butanol, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), ethylene, acetone, lipids, isopropanol, lipids, 3-hydroxypropionate (3-HP), terpenes, including isoprene, fatty acids, 2-butanol, 1,2-propanediol, 1 propanol, 1 hexanol, 1 octanol, chorismate-derived products, 3 hydroxybutyrate, 1,3 butanediol, 2- hydroxyisobutyrate, 2-hydroxyisobutyric acid, isobutylene, adipic acid, keto-adipic acid, 1,3 hexanediol, 3-methyl-2-butanol, 2-buten-1-ol, isovalerate, isoamyl alcohol, monoethylene glycol, or any combination thereof. In another embodiment, the fermentation product is incorporated into one or more articles, converted into one or more second products, or any combination thereof.

[0074] The gas fermentation process of the substrate and / or C1-carbon source using a biocatalyst provides a fermentation broth containing the product and microbial biomass. Microbial biomass is separated from the fermentation broth to generate a process stream depleted in microbial biomass. Generally, the process stream will comprise the product and some concentration of by-products and possibly impurities. For example, the process stream may comprise product ethanol as well as by products such as methanol, ethyl acetate, at least one thiol, and at least one compound having 3 or more carbon atoms. The process stream may also comprise acetaldehyde, and / or at least one aldehyde, and / or other impurities.

[0075] The remainder of the fermentation broth comprises the microbial biomass which can be recycled to the bioreactors. The fermentation broth is typically an aqueous solution. The microbial biomass comprises at least one suitable microorganism used as the biocatalyst of the fermentation process. For example, the microorganism may be selected from Escherichia coli, Saccharomyces cerevisiae, Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium saccharbutyricum, Clostridium saccharoperbutylacetonicum, Clostridium butyricum, Clostridium diolis, Clostridium kluyveri, Clostridium pasterianium, Clostridium novyi, Clostridium difficile, Clostridium thermocellum, Clostridium cellulolyticum, Clostridium cellulovorans, Clostridium phytofermentans, Lactococcus lactis, Bacillus subtilis, Bacillus licheniformis, Zymomonas mobilis, Klebsiella oxytoca, Klebsiella pneumonia, Corynebacterium glutamicum, Trichoderma reesei, Cupriavidus necator, Pseudomonas putida, Lactobacillus plantarum, and Methylobacterium extorquens. In certain instances, the microorganism may be a C1-fixing bacterium selected from Acetobacterium woodii, Alkalibaculum bacchii, Blautia producta, Butyribacterium methylotrophicum, Clostridium aceticum, Clostridium autoethanogenum, Clostridium carboxidivorans, Clostridium coskatii, Clostridium drakei, Clostridium formicoaceticum, Clostridium ljungdahlii, Clostridium magnum, Clostridium ragsdalei, Clostridium scatologenes, Eubacterium limosum, Moorella thermautotrophica, Moorella thermoacetica, Oxobacter pfennigii, Sporomusa ovata, Sporomusa silvacetica, Sporomusa sphaeroides, and Thermoanaerobacter kiuvi. In a specific embodiment, the microorganism is a member of the genus Clostridium. In certain instances, the microorganism is Clostridium autoethanogenum.

[0076] The microorganisms may be capable of producing a variety of different products. One or more products produced by the microorganisms may be a low boiling fermentation product. In certain instances, the product is ethanol, acetone, isopropanol, butanol, ketones, methyl ethyl ketone, acetone, 2-butanol, 1-propanol, methyl acetate, ethyl acetate, butanone, 1,3-butadiene, isoprene, isobutene, or any combination thereof. In certain embodiments, the method is optimized based upon the product being produced. In some embodiments, the product produced in the bioreactor is ethanol and isopropanol. The method may be optimized such that ethanol and isopropanol can be effectively removed from the fermentation broth. In some embodiments, the microorganism produces at least one by-product. In one embodiment the at least one by-product is acetic acid, lactic acid, acetone, 3-hydroxybutyrate, isobutanol, n- propanol, n-butanol, and / or 2,3-butanediol.

[0077] Known techniques for separating microbial biomass to generate the process stream comprising at least the product. For example, the fermentation broth may be passed from a bioreactor to a vacuum distillation vessel where the fermentation broth is partially vaporized to produce a product enriched stream comprising ethanol, and a product depleted stream comprising microbial biomass. Vacuum distillation is described in detail in, for example, US 10,620,802 and US 11,471,786, hereby incorporated by reference.

[0078] Extractive distillation, either alone, or in combination with vacuum distillation is another known technique that may be used to separate a process stream depleted in microbial biomass from the fermentation broth. An extractive distillation agent works by interacting with a product to increase the relative volatility between the desired product and other components. For example, an extractive distillation agent has a high affinity for the desired product and a low affinity for the by-products. A proper extractive distillation agent should not form an azeotrope with components and should be capable of being separated from the product by a subsequent separation technique such as distillation. Suitable potential extractive distillation agents are listed, for example, in US 11,807,592, hereby incorporated by reference.

[0079] Another technique involves the use of a separator module adapted to receive fermentation broth from a bioreactor and to pass the broth through a filter to yield a retentate and a permeate. Often the permeate comprises at least the product and the retentate comprises the at least the microbial biomass of the fermentation broth, which may be recycled to the bioreactor. The filter may be a membrane, such as a cross-flow membrane or a hollow fiber membrane.

[0080] The process stream, separated from the fermentation broth and depleted in microbial biomass, comprises the desired fermentation product such as ethanol, and at least one undesired byproduct or impurity. The remainder of the fermentation broth may be recycled to the bioreactor, or maybe further treated and then recycled to the bioreactor. Ethanol for use in fuel applications may require one level of purity, but other applications of ethanol may require a higher degree of purity to avoid unpleasant odor or flavors or concerns to human health. To produce the highest value ethanol, impurities or by products commonly generated and found with the ethanol in the process stream may need to be removed. Distillation is a primary technique to separate the desired ethanol. In some applications, distillation alone may be sufficient to achieve desired levels of purity. Various different distillation columns in various different configurations may be assembled to address separation needs of different applications.

[0081] In other applications standard distillation alone may not be sufficient to achieve the necessary purity levels due to the similar temperature-vapor pressure profiles of the desired ethanol and the undesired impurities or by-products. Furthermore, in some situations, azeotropes may form making distillation challenging. Enhanced distillation and or adsorptive separation removes byproduct or impurities that may affect the desired composition of which the fermentation product is a part. Multiple separation techniques in multiple separation steps may be combined to achieve the desired level of purity of the product ethanol. It is advantageous for specific separation steps to be conducted in a particular order to achieve the desired result.

[0082] Undesired byproducts and or impurities in the fermentation broth may include, among others, fusel alcohols, fusel oils, methanol, ethyl acetate, acetaldehyde, diethoxyethers, mercaptans and or organic sulfides. At times, undesired byproducts and or impurities in the fermentation broth may include esters having from 2 to about 12 carbon atoms, ethyl thioacetate, and or aromatic hydrocarbons such as toluene, xylenes, and ethylbenzene. Other undesired byproducts and or impurities in the fermentation broth may include acetic acid, 1,4 dioxane, methyl thioacetate, and or thioacetic acid. These byproducts and or impurities may have an odor that, if not removed to a suitable level, would affect the odor of a composition in which the fermentation product is used as an ingredient. It is particularly important for the fermentation product to be lacking odor from undesired byproducts and or ingredients in order for the fermentation product to be suitable for perfumes and fragrances, and for personal care products.

[0083] Hydrocarbons, such as alkanes may not have an odor, but others and particularly unsaturated, cyclic, and aromatic hydrocarbons may have an odor. Alkenes generally have a stronger smell than their corresponding alkanes. Strained alkenes have a strong unpleasant odor. Aromatic hydrocarbons often have a distinct aroma. Some hydrocarbons have a gasoline or lighter fluid-type odor. Some hydrocarbons such as esters may have a sweet smell. When producing compositions intended to have a particular smell, one approach is to use ingredients, other than the intended fragrance component, that do not have an odor of their own. That way the smell of the final article is carefully controlled using the fragrance component without interference from an order of another component ingredient. In the case of ethanol, for example, hydrocarbon impurities in gas-fermentation derived ethanol may result in the ethanol having an odor. For gas-fermentation derived ethanol to be used as one component in a compositiontargeted to have a specific smell, odor originating from the gas-fermentation derived impurities or byproducts in the ethanol can be removed prior to use.

[0084] In one embodiment, an adsorption technique is used to remove hydrocarbon impurities from fermentation derived ethanol, and particularly gas-fermentation derived ethanol. In an embodiment the adsorbent is a carbon adsorbent. As gas-fermentation derived ethanol solution is contacted with the carbon adsorbent, hydrocarbons are adsorbed onto the carbon adsorbent and removed from the ethanol. Should the carbon adsorbent become saturated and no longer have capacity to adsorb additional hydrocarbon, the carbon adsorbent may be replaced with fresh carbon adsorbent. Depending upon the type of carbon adsorbent selected, the carbon adsorbent may or may not be regenerated. For example, powdered activated carbon is not regenerated, while granular activated carbon is regenerated, typically referred to as reactivated. The fermentation derived ethanol may be contacted with any of the adsorbents described herein where the fermentation derived ethanol is in the gas state, in the liquid state, or in a mixed phase state. Many methods exist for reactivation including thermal, biological, wet oxidation, solvent, electrochemical, and catalytic wet oxidation.

[0085] A commonly used adsorbent is activated carbon which has fairly unspecific adsorptive properties and therefore is the most widely used carbon adsorbent. Activated carbon is generally obtained by carbonization, also referred to by the synonyms of smoldering, pyrolysis, burn-out, and subsequent activation of carbonaceous compounds. The constitution of the activated carbon produced, such as whether the carbon is finely or coarsely porous, firm or brittle, and the like, depends on the starting material. Customary starting materials are coconut shells, charcoal and wood including wood wastes, peat, bituminous coal, pitches, lignite coal, and also particular plastics which may play a part in the production of woven activated carbon fabrics for example. Activated carbon can be made by placing carbon containing material in a tank without oxygen and subjecting it to extremely high temperatures, 600-900 degrees Celsius. Afterwards, the carbon is exposed to different chemicals, commonly argon and nitrogen, and again placed in a tank and superheated from 600-1200 degrees Celsius. The second time the carbon is placed in the heat tank, it is exposed to steam and oxygen. Through this process, a pore structure is created, and the usable surface area of the carbon greatly increases Activated carbon is used in various forms: pulverized carbon, splint coal carbon, granulocarbon, molded carbon and also, since the end of the 1970s, spherical activated carbon “spherocarbon”. Spherical activated carbon has a number of advantages over other forms of activated carbon such as pulverized carbon, splint coal carbon, granulocarbon, molded carbonand the like that make it useful or even indispensable for certain applications: it is free flowing, abrasion resistant or to be more precise dustless, and hard. Spherocarbon is in great demand for particular applications, for example, because of its specific form, but also because of its high abrasion resistance.

[0086] Activated carbon will be discussed as the exemplary adsorbent, however activated carbon is only one selection from many different suitable adsorbents. The adsorbent is placed in a bed such as a fixed bed which may be housed in a vessel. A gas-fermentation derived ethanol stream may be contacted with the activated carbon adsorbent by passing the ethanol stream through the fixed bed. Upon contact with activated carbon, hydrocarbons that may be present in the ethanol stream are adsorbed by the activated carbon and removed from the ethanol containing stream. The adsorption technique removes hydrocarbons that may have an odor from an ethanol containing solution so that the ethanol containing solution is suitable for use in compositions where odor is important. The treatment of the process stream with activated carbon may be operated in a continuous fashion, in a batch fashion, in a swing bed fashion, or in any other suitable mode of operation. The activated carbon may be arranged in a fixed bed, a moving bed, a fluidized, a simulated moving bed or in any other suitable arrangement. The order of the separation operations as discussed here is optional, and any ordering of the separation operations may be employed.

[0087] Other odor producing impurities may be present in the ethanol solution beyond hydrocarbons including esters having from 2 to about 12 carbon atoms, and ethyl thioacetate, and methyl thioacetate. For purposes of discussion and ease of understanding, the class of ester impurities, including carboxylate esters and thiocarboxylic esters will be presented below in terms of an exemplary ester, ethyl acetate.

[0088] Ethyl acetate may be present as a by-product in the ethanol process stream, and it is desirable to remove ethyl acetate from the process stream to generate a high purity ethanol product. Ethyl acetate, and esters in general, are difficult to separate from ethanol. For example, ethyl acetate is difficult to separate from ethanol by distillation or rectification because of the closeness of their boiling points. However, the present disclosure may employ alkaline hydrolysis of esters, or more specifically, the technique of hydrolysing the ethyl acetate with a base, such as sodium hydroxide or potassium hydroxide, to form ethanol and acetic acid which is neutralized to an acetate, such as sodium acetate or potassium acetate. In an embodiment, the base is added at a location near to the feed of the process stream to the separation step. In an embodiment, the base may be added above the location of the feed of the process streaminto a column, such as for example, at a top or near to the top of the column, or in the upper one-third of the column. In an embodiment, the base may be added to the reflux return line and or the reflux pot. In an embodiment, the base may be added to a reboiler feed, especially in batch operation. In the embodiment where an acid chemical is being added, the introduction points described above would be the same. In an embodiment, the distillation column is a rectifier. In embodiments, the base may be added to a tank, to a line, and or to a distillation column. The resulting acetate is unreactive with ethanol, and the acetate is readily separated from ethanol by distillation. Exemplary suitable bases include potassium hydroxide, calcium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, barium hydroxide, ammonium hydroxide, magnesium hydroxide, and combinations thereof. In this separation step, ethyl acetate is removed from the process stream and hence from the product ethanol thus purifying the ethanol.

[0089] When the impurity is methyl thioacetate, also known as s-methyl thioacetate, the addition of a basic chemical (also generally termed as “caustic” meaning basic and not acidic) such as sodium hydroxide or potassium hydroxide results in decomposition product methane thiol and salts. In an embodiment, methane thiol may be removed from distillation in the same stream as the product ethanol. In such an embodiment, the product stream comprising both ethanol and methane thiol may be contacted with an adsorbent to adsorb and remove the methane thiol, thus purifying the ethanol. The adsorbent may be a copper-containing adsorbent, or a zeolitic adsorbent, or a silver-containing adsorbent, or another molecular sieve adsorbent. Suitable examples include copper deposited on a high surface area support (such as silica, alumina, silica-alumina, titania, zirconia, or carbon), copper metal mesh, shavings, or formed shapes, 3Å-, 4Å-, and or 5-Å molecular sieve zeolites. Copper metal and or silver metal are also suitable. The mode of operation of the contacting may be pressure swing adsorption, temperature swing adsorption, fixed bed operation, simulated moving bed operation, moving bed operation, or fluidized bed operation. If a dehydration unit employing a zeolitic adsorbent is present in the overall separation and purification process for drying the product ethanol, the dehydration unit may also be employed to remove any methane thiol. Typical dehydration units employ PSA using zeolite adsorbents. When copper metal and or silver metal are employed, and known contacting technique may be employed. As discussed above, the addition point of a basic chemical or an acidic chemical may be to a tank, to a line, or to a distillation column. The addition may be continuous or may be intermittent such as corresponding to time when a specific impurity is observed. Example 2 demonstrates the significant reduction in methylthioacetate in the distillate containing product ethanol when the technique of basic chemical addition is used. Example 3 also demonstrates the significant reduction in methyl thioacetate in the distillate containing product ethanol when the technique of basic chemical addition is used. Example 3 shows the generation of methane thiol with the basic chemical addition and the successful adsorption of methane thiol when the ethanol distillate of Run C is passed through a dehydration unit.

[0090] When the impurity is 2-methyltetrahydrothiophen-3-one (MTTO), the MTTO may be removed using distillation, such as a side draw on a distillation column. In an embodiment, the MTTO is removed, thus purifying the ethanol, using a side draw on a rectification column.

[0091] Optionally, the process stream, before or after depletion of any ethyl acetate, may be treated with an adsorbent material to remove compounds containing sulfur such as thiols. The order of the separation operations as discussed here is optional, and any ordering of the separation operations may be employed. Sulfur containing compounds are known for imparting an unpleasant odor which results in ethanol being unsuitable for some high purity applications where odor is important. Unpleasant odors in the ethanol may result from low levels of sulfur compounds, such as concentrations in the parts per billion range. Contacting the process stream comprising the at least one thiol with an adsorbent capable of adsorbing and thereby removing the thiol from the process stream will thereby remove the unpleasant odor from the stream as well. Suitable adsorbents include, for example, strongly acidic cation exchange resins. An example is a silver treated or impregnated neutralized strongly acidic ion exchange resin catalyst adsorbent. The resin may be a sulfonated styrene-divinyl benzene resin. Such synthetic resins are marketed under the name Amberlyst 15 from Rohm & Haas and LEWATIT SPC 118 from Bayer AG. A suitable adsorbent is marketed under the name Ag / Amberlyst-15 from Rohm & Haas. A suitable adsorbent is described in detail in US 4,760,204. The treatment of the process stream may be operated in a continuous fashion, in a batch fashion, in a swing bed fashion, or in any other suitable mode of operation. The adsorbent may be arranged in a fixed bed, a moving bed, a fluidized, a simulated moving bed or in any other suitable arrangement.

[0092] Optionally, in another embodiment, any mercaptans present could be oxidized using carbon or another catalyst to form disulfides in order to chemically convert the odorous mercaptans to non-odorous disulfides. Mercaptans can be challenging to remove by distillation and a catalytic process may be engaged to oxidize the mercaptans to form disulfides. Optionally, the disulfides may be extracted by dissolved in caustic for removal. Thus mercaptans may be converted into disulfides, and the disulfides may or may not be removedby extraction. Alternatively or additionally, this technique may be applied to other oxidizable impurities beyond mercaptans.

[0093] Treatment to remove sulfur compounds may be conducted in air or may be conducted in an inert atmosphere. Non limiting examples of inert atmosphere include a nitrogen atmosphere and a helium atmosphere. An advantage of using an inert atmosphere is the avoidance of producing undesired acetaldehyde. The adsorbent vessels may be purged with inert gas such as nitrogen and may be continuously purged with nitrogen.

[0094] The process stream, which may or may not be depleted in both ethyl acetate and thiol, may be distilled to separate ethanol, methanol, and at least one compound having 3 or more carbon atoms. The distillation may be accomplished in one, two, or more distillation columns. For example, a single distillation column may be used to separate the at least one compound having 3 or more carbon atoms as a bottoms stream from a methanol overhead stream and high purity ethanol side cut stream. In another embodiment, a first column may separate methanol as an overhead and a bottoms column with ethanol and at least one compound having 3 or more carbon atoms. In a second column, high purity ethanol is separated from the at least one compound having three or more carbon atoms.

[0095] One or more of the distillations may be conducted in an inert atmosphere. One or more of the distillation columns may be an extractive distillation column and employing an extractive distillation agent.

[0096] The fermentation process may produce fusel alcohols and or fusel oils as a byproduct. The fermentation broth and the process stream depleted in microbial biomass may therefore further comprise fusel alcohols and or fusel oils. fusel alcohols and or fusel oils may be removed from the process stream in the distillation step. In one embodiment, the fusel alcohols and or fusel oils are removed as a side-draw from at least one of the distillation columns. As part of the same side-draw from at least one of the distillation columns, along with fusel alcohols and or fusel oils, sulfur species may also be removed. Sulfur containing compounds that were not removed elsewhere in the process could be removed here.

[0097] The fermentation broth and the process stream may further comprise acetaldehyde. The acetaldehyde is an undesired component of the process stream and may be removed so as not to contaminate the product ethanol and reduce the purity of the product ethanol. This separation step is optional and may depend upon the amount of acetaldehyde, if any, present in the process stream. Acetaldehyde may be removed from the process stream using a metal to oxidize the acetaldehyde to an acetate followed by distillation to remove the acetate. The acetate formedmay be ethyl acetate. Therefore, in an embodiment, the acetaldehyde may be removed in the same step as the removal of ethyl acetate.

[0098] The fermentation broth and the process stream may further comprise an aldehyde. The aldehyde is an undesired component of the process stream and should be removed so as not to contaminate the product ethanol and reduce the purity of the product ethanol. The aldehyde may be chemically reduced to an alcohol and then removed from the process stream. The chemical reduction of the aldehyde may be accomplished using a reactive metal, amalgam or a compound comprising a reactive metal, or other reducing agent(s). Suitable metals, amalgams and compounds may comprise zinc or aluminium. Mixtures of different metals, amalgams and compounds may be used. Ascorbic acid may be added to the ethanol to react with some impurities and generate a reduced form of the impurities. The reduced form of the impurities may make for easier adsorption by an adsorbent. Sulfur containing compounds may be reduced into reduced forms for better absorption by an adsorbent. Similarly, sodium borohydride may be added to the ethanol to react with some impurities and generate a reduced form of the impurities. The reduced form of the impurities may make for easier adsorption by an adsorbent. Sulfur containing compounds may be reduced into reduced forms for better absorption by an adsorbent. In another embodiment, the process stream may be treated with hydrazine to react with the aldehyde and form an alkane. The alcohol produced or the alkane produced may be removed in the distillation step(s) so that the ethanol is recovered at a high purity.

[0099] The fermentation broth and the process stream may further comprise undesirable impurities. The process stream may be treated using an adsorbent to remove impurities. Suitable adsorbents are discussed above and may be selected based on the impurities present. Examples of adsorbents include activated carbon (discussed above), activated charcoal (discussed above), and silver treated or impregnated neutralized strongly acidic ion exchange resin catalyst adsorbent such as that marketed under the name Ag / Amberlyst-15. The process stream may be treated to remove impurities at any point in the process. In one embodiment, the process stream is treated to remove impurities before other separation steps. In another embodiment, the process stream is treated to remove impurities in the same step as the distillation or the removing of at least one thiol. The adsorbent may comprise any soft metal on any neutral, acidic, or basic resin or other suitable support such as silica, alumina, silica aluminates, carbon, zirconia, heteropoly acids and the like. Soft metals include, among others, lead, gold, silver, tin, zinc, aluminum, thorium, and or copper. Acidic chemicals, basic chemicals, acidic resins, basic resins and or metal oxides in general may be used to removebasic impurities such as potassium hydroxide and or sodium hydroxide. In an embodiment, a basic chemical or an acidic chemical is added to the process stream. The addition point of an acidic chemical or a basic chemical may be to a tank, to a line, or to a distillation column. Employing a resin or a metal oxide may involve an adsorbent bed where the process stream is contacted with the resin or metal oxide. The distillation column may be a rectification column. The addition may be continuous or may be intermittent such as corresponding to time when a specific impurity is observed.

[0100] In an embodiment, copper metal, a copper-containing compound, a copper additive, is contacted with or added to the process stream. The copper additive may form copper sulfides when the copper ions in solution react with sulfur-containing compounds. In an embodiment, the copper additive is a copper salt such as copper acetate. Additionally or alternatively, other copper salts may be employed. In an embodiment, copper acetate may be dissolved in water and then added to the process stream. Copper metal may also be used. The copper metal may be contacted with the process stream in known ways. Resulting copper sulfides are readily removed from the process stream. Alternatively or additionally, silver metal, a silver- containing compound, a silver additive, is contacted with or added to the process stream. The silver additive may form silver sulfides when the silver ions in solution react with sulfur- containing compounds. In an embodiment, the silver additive is a silver salt such as a silver halide such as silver chloride. The silver metal may be contacted with the process stream in known ways.

[0101] In an embodiment, a reducing agent may be added along with the copper additive. An example of a suitable reducing agent is ascorbic acid. The reducing agent may reduce some of the sulfur compounds in the process stream and make them more reactive toward the copper additive. For example, the reducing agent may cause disulfides to reduce to their mercaptan analogs, which may be more reactive with copper ions. The reducing agent, such as ascorbic acid, may also reduce the copper ions which may improve ability to react with odor causing sulfur compounds in the process stream. In an embodiment, the chemical additive, such as the copper additive, is added to the process stream before distillation such as a rectification column, a lights removal column, and or a heavies column. The benefit of added the chemical additive before distillation that the chemical additive, or the resulting compounds from reaction with the chemical additive, are less likely to pass into the final ethanol product. Other reducing agents include zinc metal and tin (II) chloride, oxalic acid. Example 4 demonstrates treatment of the process stream before distillation with a reduced copper component, copper (II) acetate.Lights removal and heavies removal were then conducted to round out the purification process. It is also envisioned that an oxidizing agent may be used to aid in the removal of one or more impurities. Oxidizing agents include hydrogen peroxide, sodium hypochlorite, calcium hypochlorite, nitric acid, and potassium perchlorate.

[0102] In the embodiment where triethyl borate is to be removed from the fermentation broth and or the process stream, a method of using a combination of sorbitol and sodium hydroxide may be employed. The method involves adding sorbitol to the fermentation broth and or the process stream, thereby forming a complex with the triethyl borate. Subsequently, sodium hydroxide is introduced to the mixture, which facilitates the hydrolysis of the triethyl borate- sorbitol complex into boric acid which is readily separated from the fermentation broth and or process steam. The resulting fermentation broth and or process steam is then in a purer form, free from triethyl borate impurity. This method provides effective and economical purification by leveraging the synergistic effects of sorbitol and sodium hydroxide under controlled conditions, thereby enhancing the overall quality of the gas fermentation broth and or process stream for further applications.

[0103] Another embodiment involves a method for purifying the process stream or fermentation broth through high pressure distillation to effectively remove impurities. High pressure distillation involves subjecting the fermentation broth or process stream to elevated pressures during distillation, which enhances the separation efficiency of volatile components. Different pressures may be used for different types of impurity profiles. For example, operation at a pressure ranging from about 50 psig (3.44 barg) to 500 psig (34.47 barg) or about 200 psig (13.79 barg) to 500 psig (34.47 barg), provides moderate higher pressure conditions suitable for removing light impurities. Operation at a pressure ranging from about 500 psig (34.47 barg), to 1000 psig (68.95 barg), may be suitable for more challenging separations, such as those involving medium volatility contaminants. Operation at a pressure ranging, from about 1001 psig (69.02 barg)to 1500 psig (103.42 barg), may be employed in applications cases where the impurities present close boiling points to the desired product, requiring more stringent separation conditions. Pressures may be adjusted within specific ranges, or different applications may call for different pressure ranges to provide efficient purification of the process stream or fermentation broth, resulting in a high-purity end product. T-butyl alcohol was tested and shown to be successfully removed using this embodiment. In another embodiment, water extractive distillation may be used in combination with the high pressure distillation.

[0104] In another embodiment, the process stream and or the fermentation broth may be dried using monoethylene glycol (MEG) extractive distillation.

[0105] In any embodiments using any type of distillation, adding anti-foam to the stream(s) fed to the distillation unit may be employed to reduce foaming and facilitate efficient distillation operation.

[0106] In another embodiment, heating, such as to a boiling point, the permeation broth, a permeate, and or feed to a distillation unit, such as a vacuum distillation unit, may be employed to denature proteins that may be present. The denatured proteins may be filtered out and the remainder of the stream introduced to any type of distillation unit.

[0107] Should heavy metals be present in the process stream, treatment though contact with an adsorbent effective for the adsorption of heavy metals may be employed.

[0108] The separation steps may be performed in any order, but there are advantages to performing the steps in a certain order. It is advantageous to remove hydrocarbons by adsorption using a carbon adsorbent prior to distillation. The advantage achieved by this particular order of the separation steps is that should any carbon fines be swept from the adsorbent bed and carried with the fluid flow of the process stream, such fines would be removed in the distillation step and prevented from inclusion in the final purified ethanol solution product. Further, separation steps described above may be omitted if not needed to remove an impurity or by product. The need may be dependent on the intended use of the ethanol, and or the presence of an impurity.

[0109] Optionally, the purified ethanol stream may be dried or dehydrated. Because ethanol forms azeotropes with water, simple distillation can dehydrate ethanol up to about 90 wt%, but removing the remaining water requires another technique. Such techniques are known, and suitable techniques include the use of membrane dehydration and adsorbent dehydration. Example membranes techniques include membrane vapor permeation or pervaporation modes. Multiple different membrane are commercially available for the dehydration of ethanol. Adsorption, and pressure swing absorption (PSA), are techniques known to produce anhydrous ethanol. Many zeolitic adsorbents are commercially available for use in PSA systems.

[0110] An exemplary 3-step purification process includes the step of treating the process stream with extractive distillation using water, followed by ethanol rectification distillation and followed by lights removal distillation. It is expected that any acetaldehyde, acetal, and other fusels are removed from the ethanol solution using extractive distillation with water as the extractant solvent. Then water and most of the fusels are removed from the bottoms product ofthe extractive distillation step in an ethanol rectification column, Side draws are placed just above the feed entrance location to remove addition fusels from the distillate product. Then acetaldehyde, methanol, acetonitrile, and other light (low boiling) components are removed in a lights distillation column.

[0111] An exemplary 5-step purification process includes the step of treating the process stream with extractive distillation using water, followed by ethanol rectification distillation and followed by lights removal distillation. Next heavies are removal by distillation which is followed by drying over a molecular sieve. It is expected that any acetaldehyde, acetal, and other fusels are removed from the ethanol solution using extractive distillation with water as the extractant solvent. Then water and most of the fusels are removed from the bottoms product of the extractive distillation step in an ethanol rectification column, Side draws are placed just above the feed entrance location to remove addition fusels from the distillate product. Then acetaldehyde, methanol, acetonitrile, and other light components are removed in a lights distillation column. In a heavies removal column, remaining fusel and other high boiling components are removed from the bottoms stream from the lights removal distillation column. Optionally, the distillate from the heavies column may be passed to a dehydration vessel containing molecular sieve o remove water and possibly sulfur components.

[0112] FIG. 5 shows an enlarged exemplary gas fermentation process including an optional gasification zone 502, a gas fermentation zone 528, a product recovery zone 544, and an optional wastewater treatment zone 534. Optional gasification process 502 receives a gasification feed 500, which may be any suitable material capable of being gasified to produce syngas stream 502. In various instances, gasification feed 500 may be comprised at least partially of sorted and / or unsorted industrial or municipal solid waste. In other instances, the gasification feed 500 is comprised at least partially of forest and / or agricultural waste. In particular embodiments, the gasification feed 500 is comprised of any combination of two or more of the following: sorted municipal or industrial solid waste, unsorted municipal or industrial solid waste, forest waste, agricultural waste, or other solid or liquid waste from the refining or chemical process integrated with the enlarged gas fermentation process. In another embodiment, gasification feed 500 comprises tire, pieces of tires, and or components of tires. In another embodiment gasification feed 500 comprises tires, pieces of tires, and or components of tires, in combination with an organic-based feed material. Integration internal to the enlarged fermentation process would also provide for at least one effluent from the fermentation process528, at least one effluent from the product recovery process 544, and or at least one effluent from the wastewater treatment process 534 being used as gasification feed.

[0113] Gasification zone 502 is to produce syngas as substrate for gas fermentation zone 528. If a gas feedstock is already present for use as substrate for gas fermentation zone, such as from the refining or chemical process integrated with the enlarged gas fermentation process, gasification zone 502 may not be required. In some embodiments, syngas 518 produced by the gasification process 502, or gas obtained from another source contains one or more constituent that needs to be removed and / or converted. Typical constituents found in the syngas stream 518 that may need to be removed and / or converted include, but are not limited to, sulfur compounds, aromatic compounds, alkynes, alkenes, alkanes, olefins, nitrogen compounds, phosphorous-containing compounds, particulate matter, solids, oxygen, halogenated compounds, silicon-containing compounds, carbonyls, metals, alcohols, esters, ketones, peroxides, aldehydes, ethers, and tars. These constituents may be removed by one or more removal zones 522 positioned between gasification zone 302 and gas fermentation zone 328. Removal zone 322 may comprise one or more of the following modules: hydrolysis module, acid gas removal module, deoxygenation module, catalytic hydrogenation module, particulate removal module, chloride removal module, tar removal module, and hydrogen cyanide polishing module. Two or more modules may be combined into a single module performing the same functions. For instance, the hydrolysis module, acid gas removal module, deoxygenation module, and catalytic hydrogenation module may be combined into a single module. When incorporating removal process 522, at least a portion of the syngas 518 from gasification zone 502 is passed to removal process 522 to remove and / or convert at least a portion of at least one constituent found in syngas stream 518. Removal zone 522 may operate to bring the constituent(s) within allowable levels to produce a treated stream 524 suitable for fermentation in gas fermentation zone 528.

[0114] Gas fermentation process 528 employs at least one C1-fixing microorganism in a liquid nutrient media to ferment a feedstock, gas, or syngas stream 518 and produce one or more product. The C1-fixing microorganism in the gas fermentation process 528 may be a carboxydotrophic bacterium. In particular embodiments, the carboxydotrophic bacterium is selected from the group comprising Moorella, Clostridium, Ruminococcus, Acetobacterium, Eubacterium, Butyribacterium, Oxobacter, Methanosarcina, Methanosarcina, Cupriavidus and Desulfotomaculum. In various embodiments, the carboxydotrophic bacterium isClostridium. In various embodiments, the carboxydotrophic bacterium is Clostridium autoethanogenum.

[0115] The one or more products produced in gas fermentation zone 528 are removed and / or separated from the fermentation broth in product recovery zone 544. Product recovery zone 544 separates and removes one or more product(s) 532 and produces at least one effluent 542, 530, 512, which comprise reduced amounts of at least one product. Product depleted effluent 542 may be passed to wastewater treatment zone 534 to produce at least one wastewater treatment zone effluent 536, which may be recycled to the gasification process 502 in line 508 and / or the fermentation process 528 in line 526.

[0116] In at least one embodiment, tail-gas effluent 514 from fermentation zone 528 is tail- gas containing gas generated by the fermentation, inert gas, and or unmetabolized substrate. At least a portion 504 of tail gas 514 may be passed to the gasification zone 502 to be used as part of the gasification feed 500. At least a portion 516 of the tail gas 514 may be passed to quench the syngas stream 518. At least a portion of the tail gas may be passed to the refinery or chemical manufacture process integrated with the enlarged gas fermentation process (not shown).

[0117] In at least one embodiment, the effluent from the fermentation zone 528 is fermentation broth 546. At least a portion of the fermentation broth 546 may be passed to product recovery zone 544. In at least one embodiment, product recovery zone 544 separates at least a portion of the microbial biomass from the fermentation broth. In various instances, at least a portion of the microbial biomass that is separated from the fermentation broth is recycled to the fermentation zone 528 via a conduit 530. In various instances, at least a portion 510 of microbial biomass-depleted water 512 that is separated from the fermentation broth 546 is recycled to the fermentation zone 528. In various instances, at least a portion 506 of the microbial biomass-depleted water 512 separated from the fermentation broth 546 is passed to optional gasification zone 502 for use as part of gasification feed 500. In certain instances, fermentation zone 528 produces fusel oil (not shown) which may also be recovered in product recovery zone 544 through any suitable means such as within the rectification column of a distillation system. In at least one embodiment, at least a portion of the fusel oil from the product recovery zone 544 is used as a heating source for one or more zones or elsewhere in the refinery or chemical process.

[0118] In various instances, at least a portion of fermentation broth 546 containing microbial biomass from fermentation zone 528 may be passed to optional gasification zone 502, withoutbeing passed to product recovery zone 544 (not shown). In various instances, at least a portion of wastewater stream 540 may be passed to optional gasification zone 502 without being passed to wastewater treatment zone 534 (not shown).

[0119] In instances where the fermentation broth is processed by the product recovery process 544, at least a portion of the microbial biomass depleted water, produced through the removal of microbial biomass from the fermentation broth, may be returned to fermentation zone 528 via a conduits 512 and 510 and / or sent via a conduits 512 and 506 to gasification zone 502. At least a portion 506 of the microbial biomass depleted water 512 may be passed to gasification zone 502 to be used as part of gasification feed 500. At least a portion 510 of the microbial biomass depleted water 512 may be passed to quench syngas stream 518. At least a portion of the effluent from product recovery zone 544 may be passed via a conduit 542 to wastewater treatment zone 534. The effluents from product recovery zone 544 may comprise reduced amounts of product and / or microbial biomass.

[0120] Wastewater treatment zone 534 receives and treats effluent from one or more zones to produce clarified water. The clarified water may be passed or recycled via a conduit 536 to one or more zones. For example, at least a portion 526 of the clarified water 536 may be passed to the fermentation zone 528, at least a portion 508 of the clarified water 536 may be passed to gasification zone 502 to be used as part of the gasification feed 500 and at least a portion 520 of the clarified water 536 may be passed to quench syngas stream 518. In certain instances, the wastewater treatment process 534 generates biomass as part of the treatment process. At least a portion of this biomass may be passed via conduit 508 to the gasification zone 502 for use as part of gasification feed 500. Wastewater treatment zone 534, as a by-product of treating microbial biomass, may produce biogas. At least a portion of the biogas may be passed via conduit 508 to gasification zone 502 to be used as part of gasification feed 500 and or via a conduit 520 to quench syngas stream 518.

[0121] Optional wastewater treatment effluent removal unit 538 is positioned downstream of wastewater treatment zone 534. At least a portion of biogas from wastewater treatment zone 534 is passed to removal unit 538 to remove and / or convert at least a portion of at least one constituent found in the biogas stream. Removal unit 538 operates to lower the concentration of constituents to within preterminal allowable levels and produce a treated stream 542, 526, 520, and / or 508 suitable to be used by the subsequent one or more zones 544, 528, 522, and / or 502, respectively. Microorganisms and Fermentation

[0122] The disclosed systems and methods integrate microbial fermentation into existing or newly built infrastructure of, for example, a gas (e.g., natural gas) transportation pipeline, oil well, or the like to convert various feedstocks, gas, or other by-products into useful products such as ethylene. As disclosed herein, the systems allow for feedstocks, gas, or other by- products to be directly provided to a bioreactor, and the bioreactor is directly connected to a system for facilitating transport of a desirable product of fermentation to an end point (e.g., a chemical plant or refinery). In particular, the disclosed systems and methods are applicable for producing useful products (e.g., ethylene, ethanol, acetate, etc.) from gaseous substrates, such as gases that may optionally contain H2, that are utilized as a carbon source by microbial cultures. Such microorganisms may include bacteria, archaea, algae, or fungi (e.g., yeast), and these classes of microorganism may be suitable for the disclosed systems and methods. In general, the selection of the microorganism(s) is not particularly limited so long as the microorganism is C1-fixing, carboxydotrophic, acetogenic, methanogenic, capable of Wood- Ljungdahl synthesis, a hydrogen oxidizer, autotrophic, chemolithoautotrophic, or any combination thereof. Among the various suitable classes of microorganisms, bacteria are particularly well suited for integration in the disclosed systems and methods.

[0123] When bacteria are utilized in the disclosed systems and methods, the bacteria may be aerobic or anaerobic, depending on the nature of the carbon source and other inputs being fed into the bioreactor or fermentation unit. Further, the bacteria utilized in the disclosed systems and methods can include one of more strains of carboxydotrophic bacteria. In particular embodiments, the carboxydotrophic bacterium can be selected from a genus including, but not limited to, Cupriavidus, Clostridium, Moorella, Carboxydothermus, Ruminococcus, Acetobacterium, Eubacterium, Butyribacterium, Oxobacter, Methanosarcina, Methanosarcina, and Desulfotomaculum. In particular embodiments, the carboxydotrophic bacterium is Clostridium. In particular embodiments, the carboxydotrophic bacterium is Clostridium autoethanogenum. In particular embodiments, the carboxydotrophic bacterium is Cupriavidus. In other particular embodiments, the carboxydotrophic bacterium is Cupriavidus necator.

[0124] A number of anaerobic bacteria are known to be capable of carrying out fermentation for the disclosed methods and system. Examples of such bacteria that are suitable for use in the invention include bacteria of the genus Clostridium, such as strains of Clostridium ljungdahlii (including those described in WO 00 / 68407, EP 117309, U.S. Pat. Nos.5,173,429, 5,593,886, and 6,368,819, WO 98 / 00558 and WO 02 / 08438), Clostridium carboxydivorans (Liou et al.,International Journal of Systematic and Evolutionary Microbiology 33: pp 2085-2091) and Clostridium autoethanogenum (Abrini et al., Archives of Microbiology 161: pp 345-351). Other suitable bacteria include those of the genus Moorella, including Moorella sp HUC22-1 (Sakai et al., (2004) Biotechnology Letters 26: pp 1607-1612), and those of the genus Carboxydothermus (Svetlichny, V. A., et al. (1991), Systematic and Applied Microbiology 14: 254-260). The disclosures of each of these publications are incorporated herein by reference. In addition, other carboxydotrophic anaerobic bacteria can be used in the disclosed systems and methods by a person of skill in the art. It will also be appreciated upon consideration of the instant disclosure that a mixed culture of two or more bacteria may be used in in the disclosed systems and methods. All of the foregoing patents, patent applications, and non-patent literature are incorporated herein by reference in their entirety.

[0125] One exemplary anaerobic bacteria that is suitable for use in the disclosed systems and methods is Clostridium. One exemplary anaerobic bacteria that is suitable for use in the disclosed systems and methods is Clostridium autoethanogenum. In some embodiments, the Clostridium autoethanogenum is a Clostridium autoethanogenum having the identifying characteristics of the strain deposited at the German Resource Centre for Biological Material (DSMZ) under the identifying deposit number 19630. In some embodiments, the Clostridium autoethanogenum is a Clostridium autoethanogenum having the identifying characteristics of DSMZ deposit number DSMZ 10061. In some embodiments, the Clostridium autoethanogenum is a Clostridium autoethanogenum having the identifying characteristics of DSMZ deposit number DSMZ 23693.

[0126] In some embodiments, the anaerobic bacteria is Clostridium carboxidivorans having the identifying characteristics of deposit number DSM15243. In some embodiments, the anaerobic bacteria is Clostridium drakei having the identifying characteristics of deposit number DSM12750. In some embodiments, the anaerobic bacteria is Clostridium ljungdahlii having the identifying characteristics of deposit number DSM13528. Other suitable Clostridium ljungdahlii strains may include those described in WO 00 / 68407, EP 117309, U.S. Pat. Nos.5,173,429, 5,593,886, and 6,368,819, WO 98 / 00558 and WO 02 / 08438, all of which are incorporated herein by reference. In some embodiments, the anaerobic bacteria is Clostridium scatologenes having the identifying characteristics of deposit number DSM757. In some embodiments, the anaerobic bacteria is Clostridium ragsdalei having the identifying characteristics of deposit number ATCC BAA-622.

[0127] In some embodiments, the anaerobic bacteria is Acetobacterium woodii. In some embodiments, the anaerobic bacteria is from the genus Moorella, such as Moorella sp HUC22-1, (Sakai et al, (2004) Biotechnology Letters, 26: pp 1607-1612). Further examples of suitable anaerobic bacteria include, but are not limited to, Morella thermoacetica, Moorella thermoautotrophica, Ruminococcus productus, Acetobacterium woodii, Eubacterium limosum, Butyribacterium methylotrophicum, Oxobacter pfennigii, Methanosarcina barkeri, Methanosarcina acetivorans, Desulfotomaculum kuznetsovii (Simpa et. al. Critical Reviews in Biotechnology, 2006 Vol.26. Pp41-65). In addition, it should be understood that other C1-fixing, carboxydotrophic anaerobes may be suitable for the disclosed systems and methods. It will also be appreciated that a mixed culture of two or more bacteria may be utilized as well.

[0128] A number of aerobic bacteria are known to be capable of carrying out fermentation for the disclosed methods and system. Examples of such bacteria that are suitable for use in the invention include bacteria of the genus Cupriavidus and Ralstonia. In some embodiments, the aerobic bacteria is Cupriavidus necator or Ralstonia eutropha. In some embodiments, the aerobic bacteria is Cupriavidus alkaliphilus. In some embodiments, the aerobic bacteria is Cupriavidus basilensis. In some embodiments, the aerobic bacteria is Cupriavidus campinensis. In some embodiments, the aerobic bacteria is Cupriavidus gilardii. In some embodiments, the aerobic bacteria is Cupriavidus laharis. In some embodiments, the aerobic bacteria is Cupriavidus metallidurans. In some embodiments, the aerobic bacteria is Cupriavidus nantongensis. In some embodiments, the aerobic bacteria is Cupriavidus numazuensis. In some embodiments, the aerobic bacteria is Cupriavidus oxalaticus. In some embodiments, the aerobic bacteria is Cupriavidus pampae. In some embodiments, the aerobic bacteria is Cupriavidus pauculus. In some embodiments, the aerobic bacteria is Cupriavidus pinatubonensis. In some embodiments, the aerobic bacteria is Cupriavidus plantarum. In some embodiments, the aerobic bacteria is Cupriavidus respiraculi. In some embodiments, the aerobic bacteria is Cupriavidus taiwanensis. In some embodiments, the aerobic bacteria is Cupriavidus yeoncheonensis.

[0129] The fermentation may be carried out in any suitable bioreactor. In some embodiments, the bioreactor may comprise a first, growth reactor in which the microorganisms (e.g., bacteria) are cultured, and a second, fermentation reactor, to which fermentation broth from the growth reactor is fed and in which most of the fermentation product (e.g. ethylene, ethanol, acetate, etc.) is produced.

[0130] It will be appreciated that for growth of the bacteria and fermentation to occur, in addition to a carbon-containing substrate gas, a suitable liquid nutrient medium will need to be fed to the bioreactor. A nutrient medium will contain vitamins and minerals sufficient to permit growth of the micro-organism used. Aerobic and anaerobic media suitable for the fermentation using carbon-containing substrate gases as the sole carbon source are known in the art. For example, suitable media are described in U.S. Pat. Nos.5,173,429, 5,593,886, WO 02 / 08438, WO2007 / 115157, and WO2008 / 115080, referred to above and all of which are incorporated herein by reference. Further, the fermentation can be carried out under appropriate conditions for the desired fermentation to occur. Reaction conditions that should be considered include pressure, temperature, gas flow rate, liquid flow rate, media pH, media redox potential, agitation rate (if using a continuous stirred tank reactor), inoculum level, maximum gas substrate concentrations, and maximum product concentrations to avoid product inhibition.

[0131] The optimum reaction conditions will depend partly on the particular micro-organism used. However, in general, it may be preferable that the fermentation be performed at a pressure higher than ambient pressure. Operating at increased pressures may allow for, for example, a significant increase in the rate of CO transfer from the gas phase to the liquid phase where it can be taken up by the micro-organism as a carbon source. This, in turn, means that the retention time (defined as the liquid volume in the bioreactor divided by the input gas flow rate) can be reduced when bioreactors are maintained at elevated pressure rather than atmospheric pressure. Also, since a given CO, or CO2and H2conversion rate is in part a function of the substrate retention time, and achieving a desired retention time in turn dictates the required volume of a bioreactor, the use of pressurized systems can greatly reduce the volume of the bioreactor required, and consequently the capital cost of the fermentation equipment.

[0132] Similarly, the temperature of the culture may vary as needed. For example, in some embodiments, the fermentation is carried out at a temperature of about 34°C to about 37° C. In some embodiments, the fermentation is carried out at a temperature of about 34°C. This temperature range may assist in supporting or increasing the efficiency of fermentation including, for example, maintaining or increasing the growth rate of bacteria, extending the period of growth of bacteria, maintaining or increasing production of the desired product (e.g., ethylene, ethanol, acetate, etc.), or maintaining or increasing CO or CO2 uptake or consumption.

[0133] Culturing of the bacteria used in in the disclosed systems and methods may be conducted using any number of processes known in the art for culturing and fermenting substrates. In some embodiments a culture of a bacterium can be maintained in an aqueous culture medium. For example, the aqueous culture medium may be a minimal anaerobic microbial growth medium. Suitable media are known in the art and described for example in U.S. Pat. Nos.5,173,429 and 5,593,886; WO 02 / 08438, and in Klasson et al (1992), Bioconversion of Synthesis Gas into Liquid or Gaseous Fuels, Enz. Microb. Technol.14:602- 608; Najafpour and Younesi (2006) Ethanol and acetate synthesis from waste gas using batch culture of Clostridium ljungdahlii. Enzyme and Microbial Technology, 38(1-2):223-228; and Lewis et al., (2002), Making the connection: conversion of biomass-generated producer gas to ethanol, Proceedings Bioenergy 2002 Conference, p.1-8.

[0134] Further general processes for using gaseous substrates for fermentation that may be utilized for the disclosed systems and methods are described in the following disclosures: WO98 / 00558, M. Demler and D. Weuster-Botz (2010), Reaction Engineering Analysis of Hydrogenotrophic Production of Acetic Acid by Acetobacterium woodii, Biotechnology and Bioengineering; D. R. Martin, A. Misra and H. L. Drake (1985), Dissimilation of Carbon Monoxide to Acetic Acid by Glucose-Limited Cultures of Clostridium thermoaceticum, Applied and Environmental Microbiology, 49(6):1412-1417. Further processes generally described in the following articles using gaseous substrates for fermentation may also be utilized: (i) K. T. Klasson, et al. (1991), Bioreactors for synthesis gas fermentations resources, Conservation and Recycling, 5:145-165; (ii) K. T. Klasson, et al. (1991), Bioreactor design for synthesis gas fermentations, Fuel, 70:605-614; (iii) K. T. Klasson, et al. (1992), Bioconversion of synthesis gas into liquid or gaseous fuels, Enzyme and Microbial Technology, 14:602-608; (iv) J. L. Vega, et al. (1989), Study of Gaseous Substrate Fermentation: Carbon Monoxide Conversion to Acetate.2. Continuous Culture, Biotech. Bioeng., 34(6):785-793; (vi) J. L. Vega, et al. (1989), Study of gaseous substrate fermentations: Carbon monoxide conversion to acetate.1. Batch culture, Biotech. Bioeng., 34(6):774-784; (vii) J. L. Vega, et al. (1990), Design of Bioreactors for Coal Synthesis Gas Fermentations, Resources, Conservation and Recycling, 3:149-160; all of which are incorporated herein by reference.

[0135] As noted above, while bacteria may be preferred microorganisms for the disclosed systems and methods, other microorganisms like yeast may also be suitable. For example, yeast that may be used in the disclosed systems and methods include genus Cryptococcus,such as strains of Cryptococcus curvatus (also known as Candida curvatus) (see Chi et al. (2011), Oleaginous yeast Cryptococcus curvatus culture with dark fermentation hydrogen production effluent as feedstock for microbial lipid production, International Journal of Hydrogen Energy, 36:9542-9550, which is incorporated herein by reference). Other suitable yeasts include those of the genera Candida, Lipomyces, Rhodosporidium, Rhodotorula, Saccharomyces, and Yarrowia. In addition, it should be understood that the disclosed systems and methods may utilize a mixed culture of two or more yeasts. Additional fungi that may be suitable for the disclosed systems and methods include, but are not limited to, fungi selected from Blakeslea, Cryptococcus, Cunninghamella, Mortierella, Mucor, Phycomyces, Pythium, Thraustochytrium and Trichosporon. Culturing of yeast or other fungi may be conducted using any number of processes known in the art for culturing and fermenting substrates using yeasts or fungi.

[0136] Typically, fermentation is carried out in any suitable bioreactor, such as a continuous stirred tank reactor (CTSR), a bubble column reactor (BCR) or a trickle bed reactor (TBR). Also, in some embodiments, the bioreactor may comprise a first, growth reactor in which the micro-organisms are cultured, and a second, fermentation reactor, to which fermentation broth from the growth reactor is fed and in which most of the fermentation product (e.g., ethylene, ethanol, acetate, etc.) is produced.

[0137] The disclosed systems and method may comprise a primary bioreactor and a secondary bioreactor. The efficiency of the fermentation processes may be further improved by a further process of recycling a stream exiting the secondary bioreactor to at least one primary reactor. The stream exiting the secondary bioreactor may contain unused substrates, salts, and other nutrient components. By recycling the exit stream to a primary reactor, the cost of providing a continuous nutrient media to the primary reactor can be reduced. This recycling step has the further benefit of potentially reducing the water requirements of the continuous fermentation process. The stream exiting the bioreactor can optionally be treated before being passed back to a primary reactor. For example, because yeasts generally require oxygen for growth, any media recycled from a secondary bioreactor to a primary bioreactor may need to have all oxygen substantially removed, as any oxygen present in the primary bioreactor will be harmful to an anaerobic culture in the primary bioreactor. Therefore, the broth stream exiting the secondary bioreactor may be passed through an oxygen scrubber to remove substantially all of the oxygen prior to being passed to the primary reactor. In someembodiments, biomass from a bioreactor (e.g., a primary bioreactor, secondary bioreactor, or any combination thereof) may be separated and processed to recover one or more products.

[0138] In some embodiments, both anaerobic and aerobic gases can be used to feed separate cultures (e.g., an anaerobic culture and an aerobic culture) in two or more different bioreactors that are both integrated into the same process stream.

[0139] As disclosed herein, the feedstock gas stream providing a carbon source for the disclosed cultures is not particularly limited, so long as it contains a carbon source. C1 feedstocks comprising methane, carbon monoxide, carbon dioxide, or any combination thereof may be preferred. Optionally, H2 may also be present in the feedstock. In some embodiments, the feedstock may comprise a gaseous substrates comprising substrate comprising carbon monoxide. In some embodiments, the feedstock may comprise a gaseous substrates comprising substrate comprising carbon dioxide. In some embodiments, the feedstock may comprise a gaseous substrates comprising substrate comprising both carbon monoxide and carbon dioxide. In some embodiments, the feedstock may comprise a gaseous substrates comprising carbon monoxide. In some embodiments, the feedstock may comprise a gaseous substrates comprising carbon dioxide. In some embodiments, the feedstock may comprise a gaseous substrates comprising carbon monoxide, carbon dioxide, or any combination thereof.

[0140] Regardless of the source or precise content of the gas used as a feedstock, the feedstock may be metered (e.g., for carbon credit calculations or mass balancing of sustainable carbon with overall products) into a bioreactor in order to maintain control of the follow rate and amount of carbon provided to the culture. Similarly, the output of the bioreactor may be metered (e.g., for carbon credit calculations or mass balancing of sustainable carbon with overall products) or comprise a valved connection that can control the flow of the output and products (e.g., ethylene, ethanol, acetate, 1-butanol, etc.) produced via fermentation. Such a valve or metering mechanism can be useful for a variety of purposes including, but not limited to, slugging of product through a connected pipeline and measuring the amount of output from a given bioreactor such that if the product is mixed with other gases or liquids the resulting mixture can later be mass balanced to determine the percentage of the product that was produced from the bioreactor.

[0141] The microorganisms of the disclosure may be cultured with the gaseous substrate to produce one or more gas fermentation products. For instance, products of interest for the disclosed systems and methods can include, but are not limited to, alcohols, acids, diacids,alkanes, alkenes, alkynes, and the like. For instance, a product of interest for the disclosed systems and method can include alcohols such as ethanol. More specifically, the microorganisms of the present disclosure may produce or may be engineered to produce ethanol (US 7,972,824), acetate (US 7,972,824), 1-butanol (US 8,293,509, US 9,359,611 and US 9,738,875), butyrate (US 8,293,509), 2,3-butanediol (US 8,658,408 and US 10,590,406), lactate (US 8,900,836), butene (US2012 / 045807), butadiene (US 2012 / 045807), methyl ethyl ketone (2-butanone) (US 2012 / 045807 and US 9,890,384), ethanol which is then converted to ethylene (US 2013 / 157,322), acetone (US 9,410, 130), isopropanol (US 9,410,130), lipids (US 9,068,202), 3-hydroxypropionate (3-HP) (US 9,994,878), terpenes, including isoprene (US 10,913,958), fatty acids (US 9,347,076), 2-butanol (US 9,890,384), 1,2-propanediol (US 9,284,564), 1-propanol (US 9,284,564), 1 hexanol (US 9,738,875), 1-octanol (US 9,738,875), chorismate-derived products (US 10,174,303), 3-hydroxybutyrate (US 9,738,875), 1,3- butanediol (US 9,738,875), 2-hydroxyisobutyrate or 2-hydroxyisobutyric acid (US 9,738,875), isobutylene (US 9,738,875), adipic acid (US 9,738,875), 1,3-hexanediol (US 9,738,875), 3-methyl-2-butanol (US 9,738,875), 2-buten-1-ol (US 9,738,875), isovalerate (US 9,738,875), isoamyl alcohol (US 9,738,875), monoethylene glycol (US 11,555,209), 2- phenylethanol (US 2021 / 0292732), ethylene (US 2023 / 407,271), proteins (US 2023 / 407,362 and US 2023 / 407,271), or any combination thereof.

[0142] The present disclosure may be in addition to the gas fermentation process shown in FIG.5 and may operate on product stream 532. Additionally or alternatively, the present disclosure may alter the streams to and or from product recovery zone 544. For example, product recovery zone 544 may be replaced with distillation zone 106, 106a, 106b 206, 306, or 406, and adsorption zone 116, 116a, 116b, 216, 316 or 416 may be added before or after distillation zone 306.

[0143] FIG.1 shows a process flow where microbial biomass is removed from fermentation broth 138 in microbial biomass removal zone 140 to form a microbial biomass-depleted process stream. The microbial biomass-depleted process stream is passed through at least one of line 142, 144, 146, or 148 to one or more separation techniques. When more than one separation technique is employed, any order may be used. Benefits are achieved in the embodiment when an adsorption technique is conducted prior to a distillation technique.

[0144] When passed though line 142, the microbial biomass-depleted process stream is passed to distillation zone 106. In distillation zone 106, certain impurities of the microbial biomass- depleted process stream are reacted with a basic chemical compound 150 that is also introducedto the distillation zone. The resulting reaction product between the impurity and the basic chemical compound, such as a salt, is readily distilled from the fermentation product. By way of example, when the fermentation product is ethanol and when an impurity is an ester, the ester and the basic chemical compound react to form a salt which is easily and readily distilled from ethanol. Purified fermentation product 152 is recovered.

[0145] When the microbial biomass-depleted process stream is passed through line 144, the microbial biomass-depleted process stream is passed to carbon bed 116 containing, for example, a fixed bed of activated carbon. In carbon bed 116, upon contacting the microbial biomass depleted process stream with the activated carbon, impurities such as hydrocarbons, including aromatics, are adsorbed by the activated carbon to provide purified fermentation product stream 152. In another embodiment, carbon bed 116 can be replaced with a high pressure distillation unit.

[0146] When the microbial biomass-depleted process stream is passed through line 146, the microbial biomass-depleted process stream is passed to a sequence of separations 106a and 116a. In this embodiment, the separation by distillation is conducted prior to the separation by adsorption. In distillation zone 106a, certain impurities of the microbial biomass-depleted process stream are reacted with a basic chemical compound 150a that is also introduced to distillation zone 106a. The resulting reaction between the impurity and the basic chemical compound generates a reaction product, such as a salt, which is readily distilled from the fermentation product. By way of example, when the fermentation product is ethanol and when an impurity is an ester, the ester and the basic chemical compound react to form a salt which is easily and readily distilled from ethanol. An intermediate purified fermentation product is passed from distillation zone 106a to adsorption zone 116a which contains a bed of adsorbent such as, for example, a fixed bed of carbon or activated carbon. In carbon bed 116a, upon contacting the microbial biomass depleted process stream with the activated carbon, impurities such as hydrocarbons, including aromatics, are adsorbed by the activated carbon to provide purified fermentation product stream 152. In another embodiment distillation zone 106a is a high pressure distillation unit, and adsorption zone 116a is replaced by a water extractive distillation unit.

[0147] When the microbial biomass-depleted process stream is passed through line 148, it is passed to a sequence of separations 116b and 106b. In this embodiment, the adsorption separation is conducted prior to the separation by distillation. The microbial biomass-depleted process stream is passed to carbon bed 116b containing, for example, a fixed bed of activatedcarbon. In carbon bed 116b, upon contacting the microbial biomass depleted process stream with the activated carbon, impurities such as hydrocarbons, including aromatics, are adsorbed by the activated carbon to provide an intermediate purified fermentation product stream. The intermediate purified product stream is passed to distillation zone 106b. In distillation zone 106b, certain impurities of the microbial biomass-depleted process stream are reacted with a basic chemical compound 150b that is also introduced to distillation zone 106b. The resulting reaction between the impurity and the basic chemical compound generates a reaction product, such as a salt, which is readily distilled from the fermentation product. By way of example, when the fermentation product is ethanol and when an impurity is an ester, the ester and the basic chemical compound react to form a salt which is easily and readily distilled from ethanol. A purified fermentation product is provided in 152. In this embodiment, when an adsorption separation is conducted prior to a distillation separation, advantages are achieved. Depending upon the impurities present, by contacting the microbial biomass depleted stream with adsorptive carbon or activated carbon prior to a distillation, a greater purity of product may be achieved. Should any fines of carbon be entrained by the fluid flow and carried into the intermediate purified fermentation product, the distillation separate operates to prevent such carbon fines from continuing into the final purified fermentation product.

[0148] Turning to FIG.2A, a flow scheme for distillation with the addition of a basic chemical compound to remove esters is shown. Gas fermentation derived ethanol solution 202 is introduced to distillation column 206. A basic chemical compound 204 is introduced to the distillation column at a location in the upper one third of distillation column 206. Base, such as sodium hydroxide, is introduced to vessel 206 in line 204. The base reacts with ethyl acetate to form sodium acetate which is removed in line 208. The ethyl acetate-depleted process stream is passed from vessel 206 in stream 210. Fusel alcohols and other intermediate boiling compounds, such as those with a lower boiling point than water and a higher boiling point than ethanol, are passed from vessel 206 in stream 212.

[0149] FIG. 2B shows a flow scheme with only the adsorptive separation. Adsorptive separation vessel 216 contains a fixed bed of activated carbon adsorbent. Microbial biomass depleted ethanol solution 214 from a gas fermentation process or partially purified ethanol solution 214 from a gas fermentation process is passed to separation vessel 216 and contacts the fixed bed of activated carbon adsorbent. Hydrocarbons including aromatic and cyclic hydrocarbons are adsorbed by the activated carbon adsorbent and removed from the ethanolsolution. At least partially purified ethanol is removed from adsorptive separation vessel 216 as stream 218.

[0150] FIG.3 shows one embodiment of the disclosure where the separation steps are arranged in a particular order. An ethanol process stream that has already been separated from fermentation broth and comprises impurities of at least one hydrocarbon and at least one ester, is conducted in line 302 and introduced to adsorption vessel 316. Adsorptive separation vessel 316 contains a fixed bed of activated carbon adsorbent. Microbial biomass depleted ethanol solution 302 from a gas fermentation process or partially purified ethanol solution 302 from a gas fermentation process is passed to separation vessel 316 and contacts the fixed bed of activated carbon adsorbent. Hydrocarbons including aromatic and cyclic hydrocarbons are adsorbed by the activated carbon adsorbent and removed from the ethanol solution. At least partially purified ethanol is removed from adsorptive separation vessel 316 as stream 318. Partially purified ethanol in stream 318 is introduced to distillation vessel 306 where esters such as ethyl acetate and ethyl thioacetate are removed. Base, such as sodium hydroxide, is introduced to vessel 306 in line 304. The base reacts with the esters such as ethyl acetate, ethyl thioacetate, and or methyl thioacetate to form a salt such as sodium acetate which are removed in line 308. The ethyl acetate-depleted process stream is passed from vessel 306 via line 320. Optional side-draw 312 is also shown where fusel alcohols, fusel oils, and / or sulfur containing compounds may be withdrawn. Purified ethanol is removed in overhead line 320. Optionally, purified ethanol in line 320 may be dried in ethanol dehydration unit (not shown) to provide purified dehydrated ethanol. Ethanol dehydration unit may be a membrane system or a PSA.

[0151] FIG.3 shows an order of separation steps that have particular benefits. Fines from the activated carbon adsorbent in adsorption vessel 316 which might be conducted by the fluid flow to exit vessel 316 in partial purified ethanol stream 318 will then be removed from the ethanol solutions by distillation in distillation column 306, and not pass into the purified ethanol stream 320.

[0152] FIG.4 shows one embodiment of the disclosure where the separation steps are arranged in a particular order. A process stream that has already been separated from fermentation broth and comprises at ethanol and least one ester and at least one hydrocarbon is conducted in line 402 and introduced to vessel 406 where ethyl acetate is removed. Base, such as sodium hydroxide, is introduced to vessel 406 in line 404. The base reacts with ethyl acetate to form sodium acetate which is removed in line 408. The ethyl acetate-depleted process stream 410 is passed from vessel 406 to adsorption vessel 416. Optional side-draw 412 is also shown wherefusel oils and / or sulfur containing compounds may be withdrawn. Adsorption vessel 416 houses an adsorbent capable of adsorbing at least one hydrocarbon. An exemplary adsorbent is activated carbon. The process stream depleted in at least one ester is passed from vessel 406 to vessel 416 in line 410. At least one hydrocarbon is adsorbed from the partially purified ethanol solution by the adsorbent in adsorption vessel 416. A purified ethanol product 422 is removed from vessel 416. Depending upon the adsorbent selected, and whether that adsorbent may be regenerated or reactivated, the hydrocarbon adsorbed by the adsorbent may be removed from the adsorbent using any number of known reactivation techniques. Optionally, purified ethanol product 422 may be dried in an ethanol dehydration unit (not shown) to provide purified dehydrated ethanol. The ethanol dehydration unit may be a membrane system or a PSA. Ethanol and Derivatives

[0153] In one embodiment, ethanol or ethyl alcohol produced according to the method of the disclosure may be used in numerous product applications, including antiseptic hand rubs (WO 2014 / 100851), therapeutic treatments for methylene glycol and methanol poisoning (WO 2006 / 088491), as a pharmaceutical solvent for applications such as pain medication (WO 2011 / 034887) and oral hygiene products (U.S. Patent No.6,811,769), as well as an antimicrobial preservative (U.S. Patent Application No.2013 / 0230609), engine fuel (US Patent No.1,128,549), rocket fuel (U.S. Patent No.3,020,708), plastics, fuel cells (U.S. Patent No.2,405,986), home fireplace fuels (U.S. Patent No.4,692,168), as an industrial chemical precursor (U.S. Patent No.3,102,875), cannabis solvent (WO 2015 / 073854), as a winterization extraction solvent (WO 2017 / 161387), as a paint masking product (WO 1992 / 008555), as a paint or tincture (U.S. Patent No.1,408,091), purification and extraction of DNA and RNA (WO 1997 / 010331), and as a cooling bath for various chemical reactions (U.S. Patent No.2,099,090). In addition to the foregoing, the ethanol generated by the disclosed method may be used in any other application for which ethanol might otherwise be applicable.

[0154] A further embodiment comprises converting the ethanol generated by the method into ethylene. This can be accomplished by way of an acid catalyzed dehydration of ethanol to give ethylene according to the following formula: CH3CH2OH → CH2=CH2 + H2O

[0155] The ethylene generated in this way may be used for a variety of applications on its own or can be used as a raw material for more refined chemical products. Specifically, ethylene alone may be used as an anesthetic, as part of a mixture with nitrogen to controlripening of fruit, as a fertilizer, as an element in the production of safety glass, as part of an oxy-fuel gas in metal cutting, welding and high velocity thermal spraying, and as a refrigerant.

[0156] As a raw material, ethylene can used in the manufacture of polymers such as polyethylene (PE), polyethylene terephthalate (PET) and polyvinyl chloride (PVC) as well as fibres and other organic chemicals. These products are used in a wide variety of industrial and consumer markets such as the packaging, transportation, electrical / electronic, textile and construction industries as well as consumer chemicals, coatings and adhesives.

[0157] Ethylene can be chlorinated to ethylene dichloride (EDC) and can then be cracked to make vinyl chloride monomer (VCM). Nearly all VCM is used to make polyvinyl chloride which has its main applications in the construction industry.

[0158] Other ethylene derivatives include alpha olefins which are used in Linear low-density polyethylene (LLDPE) production, detergent alcohols and plasticizer alcohols; vinyl acetate monomer (VAM) which is used in adhesives, paints, paper coatings and barrier resins; and industrial ethanol which is used as a solvent or in the manufacture of chemical intermediates such as ethyl acetate and ethyl acrylate.

[0159] Ethylene may further be used as a monomer base for the production of various polyethylene oligomers by way of coordination polymerization using metal chloride or metal oxide catalysts. The most common catalysts consist of titanium (III) chloride, the so-called Ziegler–Natta catalysts. Another common catalyst is the Phillips catalyst, prepared by depositing chromium (VI) oxide on silica.

[0160] Polyethylene oligomers so produced may be classified according to its density and branching. Further, mechanical properties depend significantly on variables such as the extent and type of branching, the crystal structure, and the molecular weight. There are several types of polyethylene which may be generated from ethylene, including, but not limited to: Ultra-high-molecular-weight polyethylene (UHMWPE); Ultra-low-molecular-weight polyethylene (ULMWPE or PE-WAX); High-molecular-weight polyethylene (HMWPE); High-density polyethylene (HDPE); High-density cross-linked polyethylene (HDXLPE); Cross-linked polyethylene (PEX or XLPE); Medium-density polyethylene (MDPE); Linear low-density polyethylene (LLDPE);Low-density polyethylene (LDPE); Very-low-density polyethylene (VLDPE); and Chlorinated polyethylene (CPE).

[0161] Low density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) mainly go into film applications such as food and non-food packaging, shrink and stretch film, and non-packaging uses. High density polyethylene (HDPE) is used primarily in blow molding and injection molding applications such as containers, drums, household goods, caps and pallets. HDPE can also be extruded into pipes for water, gas and irrigation, and film for refuse sacks, carrier bags and industrial lining.

[0162] According to one embodiment, the ethylene formed from the ethanol described above may be converted to ethylene oxide via direct oxidation according to the following formula: C2H4+ O2→ C2H4O

[0163] The ethylene oxide produced thereby is a key chemical intermediate in a number of commercially important processes including the manufacture of monoethylene glycol. Other EO derivatives include ethoxylates (for use in shampoo, kitchen cleaners, etc.), glycol ethers (solvents, fuels, etc.) and ethanolamines (surfactants, personal care products, etc.).

[0164] Monoethylene Glycol and Derivatives

[0165] According to one embodiment of the disclosure, the ethylene oxide produced as described above may be used to produce commercial quantities of monoethylene glycol by way of the formula: (CH2CH2)O + H2O → HOCH2CH2OH

[0166] According to another embodiment, the claimed microorganism can be modified in order to directly produce monoethylene glycol. As described in WO 2019 / 126400, the disclosure of which is incorporated by reference herein, the microorganism further comprises one or more of an enzymes capable of converting acetyl-CoA to pyruvate; an enzyme capable of converting pyruvate to oxaloacetate; an enzyme capable of converting pyruvate to malate; an enzyme capable of converting pyruvate to phosphoenolpyruvate; an enzyme capable of converting oxaloacetate to citryl-CoA; an enzyme capable of converting citryl-CoA to citrate; an enzyme capable of converting citrate to aconitate and aconitate to iso-citrate; an enzyme capable of converting phosphoenolpyruvate to oxaloacetate; an enzyme capable of converting phosphoenolpyruvate to 2-phospho-D-glycerate; an enzyme capable of converting 2- phospho-D-glycerate to 3-phospho-D-glycerate; an enzyme capable of converting 3-phospho- D-glycerate to 3-phosphonooxypyruvate; an enzyme capable of converting 3-phosphonooxypyruvate to 3-phospho-L-serine; an enzyme capable of converting 3-phospho- L-serine to serine; an enzyme capable of converting serine to glycine; an enzyme capable of converting 5,10-methylenetetrahydrofolate to glycine; an enzyme capable of converting serine to hydroxypyruvate; an enzyme capable of converting D-glycerate to hydroxypyruvate; an enzyme capable of converting malate to glyoxylate; an enzyme capable of converting glyoxylate to glycolate; an enzyme capable of converting hydroxypyruvate to glycolaldehyde; and / or an enzyme capable of converting glycolaldehyde to ethylene glycol.

[0167] Monoethylene glycol produced according to either of the described methods may be used as a component of a variety of products including as a raw material to make polyester fibers for textile applications, including nonwovens, cover stock for diapers, building materials, construction materials, road-building fabrics, filters, fiberfill, felts, transportation upholstery, paper and tape reinforcement, tents, rope and cordage, sails, fish netting, seatbelts, laundry bags, synthetic artery replacements, carpets, rugs, apparel, sheets and pillowcases, towels, curtains, draperies, bed ticking, and blankets.

[0168] MEG may be used on its own as a liquid coolant, antifreeze, preservative, dehydrating agent, drilling fluid or any combination thereof. The MEG produced may also be used to produce secondary products such as polyester resins for use in insulation materials, polyester film, de-icing fluids, heat transfer fluids, automotive antifreeze and other liquid coolants, preservatives, dehydrating agents, drilling fluids, water-based adhesives, latex paints and asphalt emulsions, electrolytic capacitors, paper, and synthetic leather.

[0169] Importantly, the monoethylene glycol produced may be converted to the polyester resin polyethylene terephthalate (“PET”) according to one of two major processes. The first process comprises transesterification of the monoethylene glycol utilizing dimethyl terephthalate, according to the following two-step process: First step C6H4(CO2CH3)2 + 2 HOCH2CH2OH → C6H4(CO2CH2CH2OH)2 + 2 CH3OH Second step n C6H4(CO2CH2CH2OH)2 → [(CO)C6H4(CO2CH2CH2O)]n + n HOCH2CH2OH

[0170] Alternatively, the monoethylene glycol can be the subject of an esterification reaction utilizing terephthalic acid according to the following reaction: n C6H4(CO2H)2+ n HOCH2CH2OH → [(CO)C6H4(CO2CH2CH2O)]n+ 2n H2O

[0171] The polyethylene terephthalate produced according to either the transesterification or esterification of monoethylene glycol has significant applicability to numerous packagingapplications such as jars and, in particular, in the production of bottles, including plastic bottles. It can also be used in the production of high-strength textile fibers such as Dacron, as part of durable-press blends with other fibers such as rayon, wool, and cotton, for fiber fillings used in insulated clothing, furniture, and pillows, in artificial silk, as carpet fiber, automobile tire yarns, conveyor belts and drive belts, reinforcement for fire and garden hoses, seat belts, nonwoven fabrics for stabilizing drainage ditches, culverts, and railroad beds, and nonwovens for use as diaper topsheets, and disposable medical garments.

[0172] At a higher molecular weight, PET can be made into a high-strength plastic that can be shaped by all the common methods employed with other thermoplastics. Magnetic recording tape and photographic film are produced by extrusion of PET film. Molten PET can be blow-molded into transparent containers of high strength and rigidity that are also virtually impermeable to gas and liquid. In this form, PET has become widely used in bottles, especially plastic bottles, and in jars. Isopropanol and Derivatives

[0173] In an additional embodiment, isopropanol or isopropyl alcohol (IPA) produced according to the method may be used in numerous product applications, including either in isolation or as a feedstock for the production for more complex products. Isopropanol may also be used in solvents for cosmetics and personal care products, de-icers, paints and resins, food, inks, adhesives, and pharmaceuticals, including products such as medicinal tablets as well as disinfectants, sterilizers, and skin creams.

[0174] The IPA produced may be used in the extraction and purification of natural products such as vegetable and animal oil and fats. Other applications include its use as a cleaning and drying agent in the manufacture of electronic parts and metals, and as an aerosol solvent in medical and veterinary products. It can also be used as a coolant in beer manufacture, a coupling agent, a polymerization modifier, a de-icing agent and a preservative.

[0175] Additionally or alternatively, the IPA produced according to the method of the disclosure may be used to manufacture additional useful compounds, including plastics, derivative ketones such as methyl isobutyl ketone (MIBK), isopropylamines and isopropyl esters. Still further, the IPA may be converted to propylene according to the following formula: CH3CH2CH2OH → CH3-CH=CH2

[0176] The propylene produced may be used as a monomer base for the production of various polypropylene oligomers by way of chain-growth polymerization via either gas-phaseor bulk reactor systems. The most common catalysts consist of titanium (III) chloride, the so- called Ziegler–Natta catalysts and metallocene catalysts.

[0177] Polypropylene oligomers so produced may be classified according to tacticity and can be formed into numerous products by either extrusion or molding of polypropylene pellets, including piping products, heat-resistant articles such as kettles and food containers, disposable bottles (including plastic bottles), clear bags, flooring such as rugs and mats, ropes, adhesive stickers, as well as foam polypropylene which can be used in building materials. Polypropylene may also be used for hydrophilic clothing and medical dressings. Commodity Chemicals and Articles

[0178] According to one embodiment, the gas fermentation product is a commodity chemical. In another embodiment, the gas fermentation product is a commodity chemical, where the commodity chemical is catalytically converted, for example, by catalytically upgrading, into molecules, or one or more second products, wherein the one or more second products are integrated into existing or newly built infrastructure or feedstock and product transportation networks. In one embodiment, wherein the commodity chemical is selected from ethanol, isopropanol, monoethylene glycol, sulfuric acid, propylene, sodium hydroxide, sodium carbonate, ammonia, benzene, acetic acid, ethylene, ethylene oxide, formaldehyde, methanol, or any combination thereof. In one embodiment, the commodity chemical is aluminum sulfate, ammonia, ammonium nitrate, ammonium sulfate, carbon black, chlorine, diammonium phosphate, monoammonium phosphate, hydrochloric acid, hydrogen fluoride, hydrogen peroxide, nitric acid, oxygen, phosphoric acid, sodium silicate, titanium dioxide, or any combination thereof. In another embodiment, the commodity chemical is acetic acid, acetone, acrylic acid, acrylonitrile, adipic acid, benzene, butadiene, butanol, caprolactam, cumene, cyclohexane, dioctyl phthalate, ethylene glycol, methanol, octanol, phenol, phthalic anhydride, polypropylene, polystyrene, polyvinyl chloride, polypropylene glycol, propylene oxide, styrene, terephthalic acid, toluene, toluene diisocyanate, urea, vinyl chloride, xylenes, or any combination thereof. Secondary Products

[0179] The disclosed systems and methods are also suitable for providing one or more secondary products that are independent of the gas fermentation product (e.g., ethylene, ethanol, acetate, etc.). For example, in certain embodiments, microbial biomass itself may be considered a secondary product. In such embodiments, biomass from a bioreactor, such as dead microorganisms, may be used as a carbon source for further fermentation by gasifyingthe biomass. Additionally or alternatively, microbial proteins or other biomass may be recovered from a bioreactor and sold / used separately from the primary product (e.g., ethylene, ethanol, acetate, 1-butanol, etc.) as a supplement, such as a nutritional supplement and / or an animal feed. Known methods for using such biomass as a nutritional supplement or animal feed are disclosed in U.S. Patent No.10,856,560, which is herein incorporated by reference.

[0180] Additionally or alternatively, biochar may be a secondary product. In embodiments that involve or comprise gasification of solid or liquid carbonaceous materials to produce a feedstock, biochar can be incidentally produced. Biochar is carbon rich and highly structured, and therefore it can be useful as, for example, fertilizer, among other applications.

[0181] Additionally or alternatively, unutilized carbon dioxide, which may be in the form of an off-gas from the gas fermentation, may be a secondary product. Such unutilized carbon dioxide will be in a stoichiometrically higher proportion in the off-gas compared to the feedstock, and this relative purity can make the carbon dioxide useful. For example, the unutilized carbon can be sequestered by an operator for the purposes of obtaining carbon credits, or it may be combined with hydrogen gas (H2), such as “green hydrogen” resulting from electrolysis, and recycled back into the gas fermenter or bioreactor as feedstock. EXAMPLE 1

[0182] A sample of gas fermentation derived ethanol solution was analyzed by GC-MS and compared to analyses, using the same analytical method, of multiple reference ethanol solutions typically used by the fragrance industry as an ingredient in products. Impurities differed between the reference ethanol solutions. With the identification of impurities in the gas fermentation derived ethanol solution as compared to the reference ethanol solutions, the most effective process for removing the identified impurities was developed. Comparative GC-MS data is shown in Table 2, with the gas fermentation derived ethanol solution shown as Sample 1.

[0183] The gas chromatograph used was an Agilent 889- gas chromatogrpah with an Agilent 5977B Mass Spec Detector. The gas chromatograph was equipped with a GERSTEL MPS Multi-Purpose Sampler, a GERSTEL TDU 2 Thermal Desorption Unit, a GERSTEL CIS 4 Cooled Injection System and aGERSTEL Twister® stir bar, 0.5 mm film thickness (PDMS phase) x 10 mm length. Samples for analysis were diluted 10:1 in reverse osmosis water and the Twister stir bar was immersed in solution and left to stir for 2 hours at 1000 rpm. Stir barwas then desorbed on the GC-MS. The GC-MS method parameters are shown in Table 1 below. TABLE 1 TDU Initial parameters 50°C, 0.60 min. delay Ramp parameters 100°C / min ramp to 250°C, 5.0 min. hold Transfer temperature 250°C Desorption mode Splitless CIS Initial parameters 45°C, 0.50 min. equilibrium Ramp parameters 12°C / s to 250°C, 2.0 min. hold Column Analytical column DB-624 UI, 60m x 0.32mm x 1.80µm TABLE 2 Reference Reference Reference Analyte Sample 1 1 2 3 Not Not Acetal Not Detected 17.35 Detected Detected Not Not Not n-Propyl Acetate Detected Detected Detected Detected Not Not Not Ethyl Isobutyrate Detected Detected Detected DetectedNot Not Not S-Ethyl Thioacetate Detected Detected Detected Detected Not Not Not Isobutyl Acetate Detected Detected Detected Detected Hexamethylcyclotrisiloxane Detected Detected Detected Detected Not Not Ethyl 2-Hydroxybutyrate Not Detected Detected Detected Detected Not Not Not Ethylbenzene Detected Detected Detected Detected Not Not Not o-Xylene Detected Detected Detected Detected Not Not Not m+p- Xylene Detected Detected Detected Detected Not Not Not Isovaleraldehyde Diethyl Acetal Detected Detected Detected Detected Octamethylcyclotetrasiloxane Detected Detected Detected Detected Not Not Decane Not Detected Detected Detected Detected Not Not Not 1,1-Diethoxy Pentane Detected Detected Detected Detected D-Limonene Not Detected Detected Detected Detected Not Undecane Not Detected Detected Detected Detected Not Not Not 1-Ethoxy Octane Detected Detected Detected Detected [(4-Hexylbenzene-1,3- Detected Detected Detected Detected diyl)bis(oxy)]bis(trimethylsilane) Not Nonanal Not Detected Detected Detected Detected Not Not 1-Nonanol Not Detected Detected Detected DetectedNot Dodecane Detected Detected Detected Detected Not Not Tetradecane Not Detected Detected Detected Detected Not Not Tridecane Not Detected Detected Detected Detected Not Not 1,1-Diethoxy Nonane Not Detected Detected Detected Detected Not Not Cyclotetradecane Not Detected Detected Detected Detected Not Not Cylcododecane Not Detected Detected Detected Detected Not Not Not 1-Dodecanol Detected Detected Detected Detected 2,4-Di-Tert-Butylphenol Not Detected Detected Detected Detected Not Not Not n-Octyl Ether Detected Detected Detected Detected Not Not Not Cyclododecane Detected Detected Detected Detected Not 2-(Dodecyloxy) Ethanol Not Detected Detected Detected Detected EXAMPLE 2

[0184] Fuel grade gas fermentation derived ethanol combined with 8 mg / kg of s-methyl thioacetate was used as feed to a distillation operation. The feed was introduced to tray 34 of a two inch diameter 52 tray distillation column. The amount of s-methyl thioacetate was measured in the product distillate. A solution of 0.1M sodium hydroxide was fed to the distillation column at tray 8, above the feed input. The sodium hydroxide reacted with s- methyl thioacetate to generate ethane thiol and sodium acetate. The sodium acetate traveled down the column and was removed as a heavy component, and little methyl thioacetate was observed in the overhead product distillate. Table 3 below shows the measured concentration of s-methyl thioacetate in the feed, in the overhead product distillate with sodium hydroxide addition, and in the overhead product distillate without sodium hydroxide addition. The datashows that methyl thioacetate concentration in the product distillate can be reduced by addition of a base, sodium hydroxide, during distillation. TABLE 3 Stream Analyzed S-Methyl Thioacetate (mg / kg) Feed stream 8.2 Product Distillate without addition of NaOH 8.7 Product Distillate with addition of NaOH 1.5 EXAMPLE 3

[0185] A gas fermentation product ethanol stream was distilled without and with basic chemical addition, and again with basic chemical addition under an inert gas blanket. Concentrations of different sulfur containing compounds were measured. Finally, the baseline distillate (without basic chemical addition) and the distillate with basic chemical addition and under an inert gas blanket were each passed though a dehydration column and the concentrations of different sulfur containing compounds were measured.

[0186] For each distillation run, the feed was introduced to tray 14 of a two inch diameter 52 tray distillation column. Distillation Run A was conducted without basic chemical addition. Distillation Run B was conducted with a 2-molar solution of potassium hydroxide introduced to the distillation column at the top of the column at tray 2. Distillation Run C was conducted with a 2-molar solution of potassium hydroxide introduced to the distillation column at the top of the column at tray 2 and with a nitrogen purge of the feed and an argon blanket at the top of the column, at the reflux, at the product, and at the feed. The amount of different sulfur containing compounds were measured in the feed and each product distillate. In Run B and Run C, the potassium hydroxide reacted with s-methyl thioacetate of the feed to generate ethane thiol and sodium acetate. The sodium acetate traveled down the column and was removed as a heavy component, and thus little methyl thioacetate was observed in the product distillates of Run B and Run C. Table 4 below shows the measured concentration of s-methyl thioacetate in the feed, in the overhead product distillate with sodium hydroxide addition, and in the overhead product distillate without sodium hydroxide addition. The data shows that methyl thioacetate concentration in the product distillate can be reduced by addition of a base, sodium hydroxide, during distillation.

[0187] An agon blanketing system was employed for Run C. A low-oxygen environment was created to minimize the formation of disulfides. Argon was flowed into the column at tray 2,and flowed into reflux, product, and feed vessels. The feed was also purged with nitrogen to remove as much oxygen as possible. The results in Table 4 show that with the inert gas in Run C, the formation of disulfides were less than in Run B which did not employ inert gas.

[0188] The distillate produced in Run C was further treated by passing through a dehydration vessel as Run D. The dehydration vessel contained 600g of 3A molecular sieve in a 2-inch diameter 18-inch length vessel. The vessel was wrapped in heating tape and skin temperature controlled to 180 C. A back pressure regulator on the outlet of the vessel was used to maintain the pressure at 75 psig (5.17 barg). Concentrations of sulfur containing compounds were measured in the outlet stream. Methane thiol, s-methyl thioacetate, and MTTO were removed by the molecular sieve in the dehydration vessel. TABLE 4 Component Run A Run B Run C Run D Total Sulfur 28.7 18.3 13.0 9.6 (mg / kg) Methane thiol 0 11.5 9.8 3.8 (mg / kg) Ethane thiol 0 0 0 0 (mg / kg) S-Methyl Thioacetate 41.2 2.0 0.78 0 (mg / kg) Dimethyl 1.3 10.3 1.9 8.4 Disulfide S-Ethyl 2.9 0 0 0 Thioacetate Ethyl Methyl 0 0.35 0 0.33 Disulfide (mg / kg) MTTO (mg / kg) 28.6 25.2 17.7 5.4 EXAMPLE 4

[0189] A solution of copper (II) acetate monohydrate and water was added to a fuel grade ethanol prior to distillation. The treatment with copper (II) acetate monohydrate was for odor treatment, to reduce the odor of the resulting purified ethanol. After treatment with copper(II) acetate monohydrate, the solution was distilled to remove light material and distilled to remove heavy material. Product purity was measured by GC and by odor analysis.

[0190] A starting material ethanol solution was analyzed by GC to determine concentrations of selected components. As Run E, to a first portion, 3,746 g of the starting material, 296.1 mg of copper (II) acetate monohydrate was dissolved in 220 g water and added to the ethanol solution, and the mixture was allowed to sit for 12 hours. Then the mixture was distilled to remove lights, and again distilled to remove heavies. The resulting final distillate was analyzed by GC to determine the concentration of selected component. As Run F, to a first portion, 2872 g, of the starting material, 371.7.1 mg of copper (II) acetate monohydrate dissolved in 247.2 g of water was added, and the mixture was allowed to sit for 12 hours. Then the mixture was distilled to remove lights, and again distilled to remove heavies. The resulting final distillate was analyzed by GC to determine the concentration of selected component. The experiments demonstrated that it is possible to produce ethanol with acceptable odor. Table 5 Component Starting Run E Run F (mg / kg) Material Acetaldehyde 4 0.9 0.5 Methanol 73 0.7 0.7 Acetone 1 0 0 2-Propanol 8 4 3.2 1-Propanol 15332 0 0 Ethyl acetate 323 0 0 Cyclohexane 0 0 0 Acetal 147 4 2.8 3-Methyl-1- 3 2.1 1.8 butanol 2-Methyl-1- 5 0.7 0.7 butanol Ethyl butyrate 22 6.9 6.3 Odor Sweet smell, Sweet smell, no n / a sulfur detected sulfur detected* * * * *

[0191] The present technology is not to be limited in terms of the particular embodiments described in this application, which are intended as single illustrations of individual aspects of the present technology. Many modifications and variations of this present technology can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the present technology, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the present technology.

[0192] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement that that prior art forms part of the common general knowledge in the field of endeavor in any country.

[0193] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. For example, any concentration range, percentage range, ratio range, integer range, size range, or thickness range is to be understood to include the value of any integer within the recited range and, when appropriate, fractions thereof (such as one tenth and one hundredth of an integer), unless otherwise indicated.

[0194] The claims are intended to cover the components and steps in any sequence which is effective to meet the intended objectives unless the context specifically indicates the contrary. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0195] Various embodiments of this invention are described herein. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. All pressures disclosed herein are absolute unless otherwise stated. All temperatures are Celsius unless otherwise stated. EMBODIMENTS OF THE DISCLOSURE

[0196] Embodiment 1. A method for purifying a fermentation product from a fermentation broth comprising microbial biomass, at least one fermentation product, and at least one impurity, the method comprising: (a) separating at least microbial biomass from the fermentation broth to generate a microbial biomass depleted process stream; (b) removing, at least one impurity from the microbial biomass depleted process stream by at least one of the following: contacting with at least one carbon bed, copper-containing adsorbent bed, silver- containing adsorbent bed, copper metal, and or silver metal; and or distilling with a basic or acidic chemical compound; and or adding a chemical compound to react with sulfur- containing compounds followed by distilling; and or high pressure distillation; and or water extractive distillation; and (c) recovering a purified fermentation product.

[0197] Embodiment 2. The method of embodiment 1 wherein the distilling with a basic or acidic chemical compound comprises adding the basic chemical compound or an acidic chemical compound at an upper one-third of a distillation column, into a reflux line, and or into a reflux pot.

[0198] Embodiment 3. The method of embodiments 1 or 2 wherein the at least one carbon bed comprises a graphite carbon, a non-graphite carbon, or any combination thereof.

[0199] Embodiment 4. The method of any of embodiment 1 to 3, wherein the at least one carbon bed comprises activated carbon or activated charcoal.

[0200] Embodiment 5. The method of any of embodiments 1 to 4, wherein the fermentation product is generated by gas fermentation of a C1 containing substrate.

[0201] Embodiment 6. The method of any of embodiments 1 to 5, wherein the fermentation product is generated by gas fermentation of a substrate comprising carbon monoxide or carbon dioxide or hydrogen or any combination thereof using a C1-fixing microorganism.

[0202] Embodiment 7. The method of any of embodiments 1 to 6, wherein the C1-fixing microorganism is an aerobic bacterium or an anerobic bacterium.

[0203] Embodiment 8. The method of any of embodiments 1 to 7 wherein both the passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, and or silver-containing adsorbent bed and the distilling with a basic or acidic chemical compound are conducted.

[0204] Embodiment 9. The method of any of embodiments 1 to 8, wherein both the passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, and or silver-containing adsorbent bed and the distilling with a basic or acidic chemical compound are conducted prior to the distilling with a basic or acidic chemical compound.

[0205] Embodiment 10. The method of any of embodiments 1 to 9, further comprising dehydrating the purified fermentation product.

[0206] Embodiment 11. The method of any of embodiments 1 to 10, wherein the fermentation product is selected from ethylene, ethanol, propane, acetate, 1-butanol, butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), acetone, isopropanol, a lipid, 3-hydroxypropionate (3-HP), a terpene, isoprene, a fatty acid, 2-butanol, 1,2-propanediol, 1propanol, 1hexanol, 1octanol, chorismate-derived products, 3hydroxybutyrate, 1,3butanediol, 2-hydroxyisobutyrate or 2-hydroxyisobutyric acid, isobutylene, adipic acid, 1,3hexanediol, 3-methyl-2-butanol, 2-buten-1-ol, isovalerate, isoamyl alcohol, and monoethylene glycol, or any combination thereof.

[0207] Embodiment 12. A composition comprising: (a) a purified fermentation product; and (b) a fragrance component selected from agrumen, aliphatic aldehydes, amber, ambergris, ambrette, amyris, benzoin, bergamot, black pepper, calone, cashmeran, castoreum, citron, civet, clary sage, coumarin, frangipani, frankincense, galbanum, guaiac wood, hedione, heliotrope, indole, iso e super, jasmone, labdanum, lavender, lily of the valley, magnolia, mandarin, monoi, muguet, musk, myrrh, narcissus, neroli, oakmoss, opopanax, orris, osmanthus, oud, patchouli, rose, rose de mai, sandalwood, tonka bean, vanilla, vetiver, ylang- ylang, and any combination thereof; wherein the purified fermentation product is recovered from a fermentation broth comprising microbial biomass, at least one fermentation product, and at least one impurity, by separating at least microbial biomass from the fermentation broth to generate a microbial biomass-depleted process stream and removing the at least one impurity from the microbial biomass-depleted process stream by contacting with at least onecarbon bed, copper-containing adsorbent bed, silver-containing adsorbent bed, copper metal and or silver metal; distilling with a basic or acidic chemical compound; or adding a chemical compound to react with sulfur-containing compounds followed by with distilling.

[0208] Embodiment 13. The composition of any of embodiment 12 wherein the fermentation broth is generated in a gas fermentation process.

[0209] Embodiment 14. The composition of any of embodiments 12 or 13 wherein the distilling with a basic or acidic chemical compound comprises adding the basic chemical compound or the acidic chemical compound at an upper one-third of a distillation column, into a reflux line, and or into a reflux pot.

[0210] Embodiment 15. The composition of any of embodiment 12 to 14, wherein the at least one carbon bed comprises a graphite carbon, a non-graphite carbon, or any combination thereof.

[0211] Embodiment 16. The composition of any of embodiments 12 to 15, wherein the at least one carbon bed comprises activated carbon or activated charcoal.

[0212] Embodiment 17. The composition of any of embodiments 12 to 16, wherein the fermentation product is generated by gas fermentation of a C1 containing substrate.

[0213] Embodiment 18. The composition of any of embodiments 12 to 17, wherein the fermentation product is generated by gas fermentation of a substrate comprising carbon monoxide or carbon dioxide or hydrogen or any combination thereof using a C1-fixing microorganism.

[0214] Embodiment 19. The composition of any of embodiments 12 to 18, wherein the C1- fixing microorganism is an aerobic bacterium or an anerobic bacterium.

[0215] Embodiment 20. The composition of any of embodiments 12 to 19, wherein both the passing the microbial biomass-depleted stream over at least one carbon bed and the distilling with a basic chemical compound are conducted.

[0216] Embodiment 21. The composition of any of embodiments 12 to 20, wherein the passing the microbial biomass-depleted stream over at least one carbon bed, copper containing adsorbent bed, or silver containing adsorbent bed is conducted prior to the distilling with a basic or acidic chemical compound.

[0217] Embodiment 22. The composition of any of embodiments 12 to 21, wherein the purified fermentation product is a hydrated fermentation product.

[0218] Embodiment 23. The composition of any of embodiments 12 to 22, wherein the purified fermentation product is selected from ethylene, ethanol, propane, acetate, 1-butanol,butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), acetone, isopropanol, a lipid, 3-hydroxypropionate (3-HP), a terpene, isoprene, a fatty acid, 2- butanol, 1,2-propanediol, 1propanol, 1hexanol, 1octanol, chorismate-derived products, 3hydroxybutyrate, 1,3butanediol, 2-hydroxyisobutyrate or 2-hydroxyisobutyric acid, isobutylene, adipic acid, 1,3hexanediol, 3-methyl-2-butanol, 2-buten-1-ol, isovalerate, isoamyl alcohol, and monoethylene glycol, or any combination thereof.

[0219] Embodiment 24. The composition of any of embodiments 12 to 23, wherein the composition is selected from fragrances, personal care products, cosmetics, and home care products.

[0220] Embodiment 25. The composition of any of embodiments 12 to 14, wherein the composition is selected from perfume, cologne, eau de Toilette, Eau de Parfum, aftershave, hair care products, hair dye, hair shampoo, hair conditioner, hair spray, shower gel, soap, body lotion, body spray, mouth wash, deodorants, antiperspirants, laundry detergents, fabric softeners, fabric dye, dryer sheets, room fresheners, air fresheners, carpet fresheners, essential oils, cleaning products, polishing products, scouring or abrasive products, toiletries, sanitary preparations, tissue, nail products, diapers, bandages, sunscreen, nourishing cream, hand cream, lipstick, lip gloss, sun oil, massage cream, cleansing cream, facial pack, serums for cosmetic purposes, cocoa butter, skin care product, retinol cream, muscle gel, body paint, cooling spray, cold cream, pomade, cleaning products, dishwashing liquid, hand sanitizers, sanitizing gels, sanitizing wipes, shampoos other than hair shampoo household products, pet care products, pet shampoo, pet cleaning, animal deterrents, candles, car care products, industrial fragrances, and fragrance oils.

[0221] Embodiment 26. An apparatus for separating ethanol from a fermentation broth comprising microbial biomass, ethanol, at least one hydrocarbon and at least one ester, the apparatus comprising: (a) a first separation unit, in fluid communication with a bioreactor, configured to separate at least microbial biomass from the fermentation broth and generate a process stream comprising ethanol, at least one impurity; (b) at least one second separation unit, in fluid communication with the first separation unit, selected from: an adsorptive separation unit comparing a carbon adsorbent, a copper containing adsorbent, and or a silver containing adsorbent; a distillation separation unit equipped to add a basic or acidic chemical to the distillation; a chemical addition unit followed by at least two distillation columns; a high pressure distillation unit; and a high pressure distillation unit in combination with awater extractive distillation unit; and (c) a purified ethanol conduit in fluid communication with the at least one separation unit.

[0222] Embodiment 27. A composition comprising: (a) a purified fermentation product; and (b) a fragrance component selected from agrumen, aliphatic aldehydes, amber, ambergris, ambrette, amyris, benzoin, bergamot, black pepper, calone, cashmeran, castoreum, citron, civet, clary sage, coumarin, frangipani, frankincense, galbanum, guaiac wood, hedione, heliotrope, indole, iso e super, jasmone, labdanum, lavender, lily of the valley, magnolia, mandarin, monoi, muguet, musk, myrrh, narcissus, neroli, oakmoss, opopanax, orris, osmanthus, oud, patchouli, rose, rose de mai, sandalwood, tonka bean, vanilla, vetiver, ylang- ylang, and any combination thereof; wherein the purified fermentation product is recovered from a fermentation broth comprising microbial biomass, at least one fermentation product, and at least one impurity, by separating at least microbial biomass from the fermentation broth to generate a microbial biomass-depleted process stream and removing the at least one impurity from the microbial biomass-depleted process stream by: high pressure distillation and or water extractive distillation.

Claims

CLAIMS 1. A method for purifying a fermentation product from a fermentation broth comprising microbial biomass, at least one fermentation product, and at least one impurity, the method comprising: a) separating at least microbial biomass from the fermentation broth to generate a microbial biomass depleted process stream; b) removing, at least one impurity from the microbial biomass depleted process stream by at least one of the following: i) contacting with at least one carbon bed, copper-containing adsorbent bed, silver- containing adsorbent bed, copper metal, and or silver metal; ii) distilling with a basic or acidic chemical compound; iii) adding a chemical compound to react with sulfur-containing compounds followed by distilling; iv) high pressure distillation; or v) high pressure distillation and water extractive distillation; and c) recovering a purified fermentation product.

2. The method of claim 1 wherein the distilling with a basic or acidic chemical compound comprises adding the basic or acidic chemical compound at an upper one-third of a distillation column, into a reflux return line, into a reflux pot, or any combination thereof.

3. The method of claim 1 wherein the at least one carbon bed comprises a graphite carbon, a non-graphite carbon, activated carbon, activated charcoal or any combination thereof.

4. The method of claim 1 wherein the fermentation product is generated by gas fermentation of a substrate comprising carbon monoxide or carbon dioxide or hydrogen or any combination thereof using a C1-fixing microorganism.

5. The method of claim 4 wherein the C1-fixing microorganism is an aerobic bacterium or an anerobic bacterium.

6. The method of claim 1 wherein both the passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, and or silver-containing adsorbent bed and the distilling with a basic or acidic chemical compound are conducted.

7. The method of claim 6 wherein the passing the microbial biomass-depleted stream over at least one carbon bed, copper-containing adsorbent bed, and or silver-containing adsorbent bed is conducted prior to the distilling with a basic or acidic chemical compound.

8. The method of claim 1 further comprising dehydrating the purified fermentation product.

9. The method of claim 1 wherein the fermentation product is selected from ethylene, ethanol, propane, acetate, 1-butanol, butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), acetone, isopropanol, a lipid, 3-hydroxypropionate (3-HP), a terpene, isoprene, a fatty acid, 2-butanol, 1,2-propanediol, 1propanol, 1hexanol, 1octanol, chorismate-derived products, 3hydroxybutyrate, 1,3butanediol, 2-hydroxyisobutyrate or 2- hydroxyisobutyric acid, isobutylene, adipic acid, 1,3hexanediol, 3-methyl-2-butanol, 2- buten-1-ol, isovalerate, isoamyl alcohol, and monoethylene glycol, or any combination thereof.

10. A composition comprising: a) a purified fermentation product; and b) a fragrance component selected from agrumen, aliphatic aldehydes, amber, ambergris, ambrette, amyris, benzoin, bergamot, black pepper, calone, cashmeran, castoreum, citron, civet, clary sage, coumarin, frangipani, frankincense, galbanum, guaiac wood, hedione, heliotrope, indole, iso e super, jasmone, labdanum, lavender, lily of the valley, magnolia, mandarin, monoi, muguet, musk, myrrh, narcissus, neroli, oakmoss, opopanax, orris, osmanthus, oud, patchouli, rose, rose de mai, sandalwood, tonka bean, vanilla, vetiver, ylang-ylang, and any combination thereof; wherein the purified fermentation product is recovered from a fermentation broth comprising microbial biomass, at least one fermentation product, and at least one impurity, by separating at least microbial biomass from the fermentation broth to generate a microbial biomass-depleted process stream and removing the at least one impurity from the microbial biomass-depleted process stream by: contacting with at least one carbon bed, copper-containing adsorbent bed, silver-containing adsorbent bed, copper metal and or silver metal; distilling with a basic or acidic chemical compound; adding a chemical compound to react with sulfur-containing compounds followed by with distilling.

11. The composition of claim 10 wherein the fermentation broth is generated in a gas fermentation process.

12. The composition of claim 10 wherein the distilling with a basic or acidic chemical compound comprises adding the basic or acidic chemical compound at an upper one-third of a distillation column, into a reflux line, or into a reflux pot.

13. The composition of claim 10 wherein the at least one carbon bed comprises a graphite carbon, a non-graphite carbon, activated carbon, activated charcoal or any combination thereof.

14. The composition of claim 10 wherein the purified fermentation product is generated by gas fermentation of a substrate comprising carbon monoxide or carbon dioxide or hydrogen or any combination thereof using a C1-fixing microorganism.

15. The composition of claim 14, wherein the C1-fixing microorganism is an aerobic bacterium or an anerobic bacterium.

16. The composition of claim 10 wherein the purified fermentation product is generated using both the passing the microbial biomass-depleted stream over at least one carbon bed, copper containing adsorbent bed, and or silver containing adsorbent bed and the distilling with a basic or acidic chemical compound.

17. The composition of claim 10 wherein the purified fermentation product is generated using both the passing the microbial biomass-depleted stream over at least one carbon bed, copper containing adsorbent bed, and or silver containing adsorbent bed and the distilling with a basic or acidic chemical compound, and in that order.

18. The composition of claim 10 wherein the purified fermentation product is a dehydrated purified fermentation product.

19. The composition of claim 10 wherein the purified fermentation product is selected from ethylene, ethanol, propane, acetate, 1-butanol, butyrate, 2,3-butanediol, lactate, butene, butadiene, methyl ethyl ketone (2-butanone), acetone, isopropanol, a lipid, 3- hydroxypropionate (3-HP), a terpene, isoprene, a fatty acid, 2-butanol, 1,2-propanediol, 1propanol, 1hexanol, 1octanol, chorismate-derived products, 3hydroxybutyrate, 1,3butanediol, 2-hydroxyisobutyrate or 2-hydroxyisobutyric acid, isobutylene, adipic acid, 1,3hexanediol, 3-methyl-2-butanol, 2-buten-1-ol, isovalerate, isoamyl alcohol, and monoethylene glycol, or any combination thereof.

20. The composition of claim 10 wherein the composition is selected from fragrances, personal care products, cosmetics, and home care products.

21. The composition of claim 10 wherein the composition is selected from perfume, cologne, eau de Toilette, Eau de Parfum, aftershave, hair care products, hair dye, hair shampoo, hair conditioner, hair spray, shower gel, soap, body lotion, body spray, mouth wash, deodorants, antiperspirants, laundry detergents, fabric softeners, fabric dye, dryer sheets, room fresheners, air fresheners, carpet fresheners, essential oils, cleaning products, polishingproducts, scouring products, abrasive products, toiletries, sanitary preparations, tissue, nail products, diapers, bandages, sunscreen, nourishing cream, hand cream, lipstick, lip gloss, sun oil, massage cream, cleansing cream, facial pack, serums for cosmetic purposes, cocoa butter, skin care product, retinol cream, muscle gel, body paint, cooling spray, cold cream, pomade, cleaning products, dishwashing liquid, hand sanitizers, sanitizing gels, sanitizing wipes, shampoos other than hair shampoo, household products, pet care products, pet shampoo, pet cleaning, animal deterrents, candles, car care products, industrial fragrances, and or fragrance oils.

22. An apparatus for separating ethanol from a fermentation broth comprising microbial biomass, ethanol, at least one impurity, the apparatus comprising: a) a first separation unit, in fluid communication with a bioreactor, configured to separate at least microbial biomass from the fermentation broth and generate a process stream comprising ethanol, at least one impurity; b) at least one second separation unit, in fluid communication with the first separation unit, selected from: i) an adsorptive separation unit comparing a carbon adsorbent, a copper containing adsorbent, and or a silver containing adsorbent; ii) a distillation separation unit equipped to add a basic or acidic chemical to the distillation; iii) a chemical addition unit followed by at least two distillation columns; iv) a high pressure distillation unit; v) a high pressure distillation unit in combination with a water extractive distillation unit; and c) a purified ethanol conduit in fluid communication with the at least one separation unit.

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