EA043304B1 - INTEGRATED PROCESS FOR FILTERING COMPONENTS FROM GAS FLOW - Google Patents

Description

Cross reference to related application

The application claims benefit to U.S. Provisional Application Nos. 62/629,160 and 62/656,813, filed February 12, 2018 and April 12, 2018, respectively, the contents of which are incorporated herein by reference.

Field of technology

The present invention relates to systems and methods for removing components from a gas stream. In particular, the invention relates to the removal of components from a gas stream that may have a detrimental effect on subsequent purification modules and/or gas fermenting microorganisms in subsequent process steps.

State of the art

There is an urgent need to significantly reduce emissions associated with global fossil fuel consumption to reduce the impact on climate change. However, carbon-based materials, chemicals and transportation fuels are primarily produced from fossil sources and there is currently no alternative source to adequately replace them.

Gas-fermenting microorganisms that bind carbon dioxide (CO ₂ ) and carbon monoxide (CO) can reduce this dependence because they can convert carbon gas into useful fuels and chemicals.

Gas fermenting microorganisms can utilize a wide range of feedstocks, including gasified organic matter of any kind (eg, municipal solid waste, industrial waste, biomass, and agricultural residues) or industrial waste gases (eg, from steel mills or other processing plants).

The wide range of industries that produce these gas streams invariably introduce impurities due to the nature of the process and elements contained in trace amounts in the process feedstock. These impurities can influence the conversion efficiency of gas-fermenting microorganisms in subsequent stages. For example, mononitrogenous substances may be present such as hydrogen cyanide (HCN), ammonia (NH ₃ ), nitric oxide (NO _x ) and other known enzyme inhibitory gases such as acetylene (C ₂ H ₂ ), ethylene (C ₂ H ₄ ), ethane (C2H6), BTEX (benzene, toluene, ethylbenzene, xylene) and oxygen ( _O2 ). Sulfur compounds in the gas such as hydrogen sulfide (H2S), carbonyl sulfide (COS), carbon disulfide (CS2) can, in turn, negatively affect catalyst-based purification systems.

For many of the above compounds, there are commercially available removal systems; however, these systems have not been used for microbial gas fermentation. Microbial gas fermentation, as a downstream process, is a relatively new alternative to traditional catalytic conversion technologies and requires relatively specific impurity restrictions. To ensure efficient uninhibited fermentation of gases, purification of these gases must be completed.

There are three major problems associated with gas purification for gas fermentation, including (1) excessive consumption of required microbial fermentation reagents; (2) reaction to form other undesirable compounds that will act as microbial inhibitors; and (3) reducing the amount of inhibitory compounds in the feed stream to levels low enough to allow efficient uninhibited gas fermentation.

Accordingly, there remains a need for an invention that strategically purifies gas streams obtained from industrial or other processes to provide gas suitable for a subsequent fermentation process while avoiding the above-mentioned problems.

Brief description of the invention

The invention provides a method for producing a fermentable gas stream from an incoming gas stream containing CO, CO2 or H2, or a combination thereof, comprising supplying the incoming gas stream to a hydrolysis module, in which at least one component of the gas stream is removed and/or converted to produce gas stream after hydrolysis, passing the gas stream obtained after hydrolysis through an acid gas removal module, where at least one additional component of the gas stream is removed and/or converted to produce a gas stream with a low acid gas content, passing the gas stream with a low acid gas content through a deoxygenation module, where at least one additional component is removed and/or converted to produce a fermentable gas stream. The order of these removal processes is critical to the successful production of a gas stream suitable for fermentation.

In at least one embodiment of the invention, at least one removed component is a microbial inhibitor and/or a catalyst inhibitor.

In specific embodiments of the invention, at least one or more of the components removed and/or converted by the hydrolysis module is carbonyl sulfide (COS) and/or hydrogen cyanide (HCN).

The components removed and/or converted by the acid gas removal module may be selected from the group consisting of carbon dioxide (CO ₂ ), hydrogen sulfide (H ₂ S) and hydrogen cyanide

- 1 043304 (HCN).

In specific embodiments of the invention, at least one or more of the components removed and/or converted by the deoxygenation module is oxygen (O2) and/or acetylene (C2H2).

In certain cases, the incoming gas stream is supplied to the acid gas removal module without passing through the hydrolysis module.

The process may further include a catalytic hydrogenation module. In embodiments of the invention using a catalytic hydrogenation module, the low acid gas gas stream is passed through the catalytic hydrogenation module before being sent to the deoxygenation module, where at least one component from the low acid gas gas stream is removed and/or converted before how to direct the gas flow to the deoxygenation module. At least one component removed and/or converted by the catalytic hydrogenation module is acetylene (C2H2).

The process may include at least one additional module selected from the group consisting of: a solids removal module, a chloride removal module, a tar removal module, a hydrogen cyanide removal module, an additional acid gas removal module, a temperature module, and a pressure module. .

In specific cases, the optional acid gas removal module is a pressure swing adsorption (PSA) module.

In specific embodiments of the invention, the method includes monitoring devices for measuring the level of components present in the gas stream. One or more control devices may be placed before and/or after one or more modules. In certain cases, one or more modules may be bypassed depending on the level of one or more components in the gas stream.

The method may include a hydrogen cyanide removal module into which a gas stream is supplied after deoxygenation. The hydrogen cyanide removal module may remove at least a portion of the hydrogen cyanide from the gas stream before supplying the gas stream to the bioreactor.

Preferably, before entering the bioreactor, the levels of the components are reduced to predetermined levels, which ensures the ability of the gas stream to ferment. In specific embodiments, the predetermined component level includes no more than one hundred parts per million (100 ppm) oxygen (O2), one part per million (1 ppm) hydrogen cyanide (HCN), and one part per million ( 1 ppm) acetylene (C2H2). In certain cases, the specified constituent level includes no more than one hundred parts per billion (100 ppb) of hydrogen cyanide (HCN).

The bioreactor may contain a culture that includes a fermentation broth and one or more microorganisms. In specific embodiments of the invention, one or more microorganisms is a carboxydotrophic bacterium.

The method may allow the purified gas stream to be supplied to the carbon capture device instead of or before the purified gas stream is supplied to the bioreactor.

In specific embodiments of the invention, the method allows for obtaining gas streams from one or more sources. At least a portion of the gas stream may be obtained from a commercial source. In addition, at least a portion of the gas stream may be synthetic gas. In addition, at least a portion of the gas stream may be producer gas.

In specific embodiments, the invention provides a method of producing a fermentable gas stream, comprising purifying a gas stream containing CO, CO2 or H2 by treating the gas to remove one or more undesirable components from the gas stream, wherein the step of treating the gas stream includes passing the gas stream through a module hydrolysis, wherein at least one component of the gas stream is converted to produce a post-hydrolysis stream, passing the stream obtained from hydrolysis through an acid gas removal module, wherein at least one additional component of the stream is removed to produce a stream with low acid gas content, and passing the stream low acid gas content through a deoxygenation module in which at least one additional component is converted to produce a fermentable gas stream.

Preferably, the fermentation gas stream contains negligible levels of oxygen (O ₂ ), hydrogen cyanide (HCN) and acetylene (C ₂ H ₂ ) compared to the incoming gas stream before passing through the treatment process.

In one embodiment of the invention, the fermentable gaseous substrate contains less than one hundred parts per million (100 ppm) of oxygen (O2).

In one embodiment of the invention, the fermentable gaseous substrate contains less than one part per million (1 ppm) of hydrogen cyanide (HCN). Preferably, the fermentable gaseous substrate contains less than one hundred parts per billion (100 ppb) of hydrogen cyanide (HCN).

In one embodiment of the invention, the fermentable gaseous substrate contains less than one part per million (1 ppm) of acetylene (C2H2).

- 2 043304

In various embodiments of the invention, the method uses one or more special catalysts to produce a fermentable gas stream from the incoming gas stream. Preferably, a special catalyst is used to reduce oxygen to less than 100 ppm, acetylene to less than 1 ppm, and hydrogen cyanide to less than 1 ppm. In certain cases, the specialty catalyst comprises reduced copper metal on a high surface area catalyst such as silica, alumina, titanium dioxide, cerium oxide, lanthanum oxide, aluminosilicate, carbon, or many other materials known to those skilled in the art. In some cases, copper (I) supported on alumina is used as a special catalyst. In some cases, the special catalyst contains sulfided copper (I) supported on aluminum oxide, which provides resistance to sulfur. In some cases, the specialized catalyst contains copper(II) supported on alumina. In some cases, the special catalyst contains sulfided copper (II) supported on aluminum oxide, which provides resistance to sulfur. Preferably, the special catalyst contains sulfided copper supported on alumina when treating the high sulfur content of the incoming gas stream.

In various embodiments of the invention, the method receives an input stream containing varying levels of various components. In some cases, the incoming gas stream contains no more than 7000 ppm oxygen, no more than 700 ppm acetylene, and no more than 60 ppm hydrogen cyanide, which may be gas derived from steel mills. plant In some cases, the influent contains up to 10,000 ppm oxygen, up to 1,500 ppm acetylene, and up to 500 ppm hydrogen cyanide, which may represent a gas stream from a gasification (biomass) process. or municipal solid waste), or purified coke oven gas. Preferably, the process consumes less than 10% of the carbon monoxide contained in the incoming gas stream. In some cases, the process may be carried out under pressure. For example, the process may be carried out at a pressure of at least 138 kPa(g).

At least a portion of the fermentation gas stream may be directed to a bioreactor containing a culture of O-fixing microorganisms. Preferably, the O-fixing microorganism is a carboxydotrophic bacterium. The carboxydotrophic bacterium may be selected from the group consisting of Moorella, Clostridium, Ruminococcus, Acetobacterium, Eubacterium, Butyribacterium, Oxobacter, Methanosarcina, and Desulfotomaculum.

Preferably the carboxydotrophic bacterium is Clostridium autoethanogenum.

In some cases, the industrial source is selected from the group consisting of: ferrous metal production, such as steel production, non-ferrous metal production, petroleum refining, coal gasification, power generation, pure carbon production, ammonia production, methanol production, and coke production .

In some cases, the source of synthesis gas is selected from the group consisting of: gasification of coal or refinery residues, gasification of biomass or lignocellulosic material, reformation of natural gas, and gasification of municipal solid waste or industrial solid waste.

Brief description of the figures

In fig. Figure 1 is a process integration flow diagram showing the integration of the hydrolysis module, acid gas removal module, and deoxygenation module.

In fig. 2 is a process integration flow diagram illustrating bypass of a hydrolysis module in accordance with one aspect of the invention.

In fig. 3 shows a process integration flowchart further including a catalytic hydrogenation module and bypass functions, in accordance with one aspect of the invention.

In fig. 4 illustrates a process integration flowchart further including one or more additional modules and bypass functions, in accordance with one aspect of the invention.

Detailed Description of the Invention

The inventors have determined that by integrating a number of purification modules, certain components can be removed from the gas that would inhibit the operation of downstream purification modules and/or the subsequent fermentation process. In particular, the inventors have determined the critical order of arrangement of the purification modules to ensure successful production of a gas stream suitable for fermentation. In addition, the inventors found that these modules were effective in removing inhibitory components without consuming significant amounts of the desired compounds or producing undesired compounds.

Definitions

Unless otherwise specified, the following terms as used in this specification have the meanings given below.

The term gasification and the like should be interpreted as a process that converts organic or fossil fuels based on carbonaceous materials into carbon monoxide (CO), hydrogen ( _H2 )

- 3 043304 and carbon dioxide (CO2).

The term synthesis gas should be interpreted to mean a gas stream commonly used in the synthetic production of chemicals.

The term generator gas should be interpreted to mean a gas stream typically used as an energy source for the generation of heat and/or power.

The terms increased efficiency, increased efficiency, and the like, when used in relation to a fermentation process, include, but are not limited to, an increase in one or more of the growth rates of microorganisms catalyzing the fermentation, the growth and/or rate of product production at increased product concentrations, the volume required product produced per volume of substrate consumed, production rate or level of production of the desired product, and the relative content of the desired product produced compared to other fermentation by-products.

Gaseous substrates containing carbon monoxide, a gas stream containing carbon monoxide and the like, as used herein, include any gas that contains carbon monoxide. The gas stream typically contains a significant proportion of CO, preferably at least about 5% to about 100% CO by volume. Although the substrate does not necessarily contain hydrogen, the presence of H2 should not adversely affect product formation in accordance with the methods of the present invention. In certain embodiments of the invention, the presence of hydrogen leads to an improvement in the overall efficiency of alcohol production. For example, in certain embodiments of the invention, the gas stream may contain H ₂ and CO in a ratio of about 2:1, or 1:1, or 1:2. In one embodiment, the gas stream contains about 30% or less H2 by volume, about 20% or less H2 by volume, about 15% or less H2 by volume, or about 10% or less H2 by volume. In other embodiments, the gas stream contains low concentrations of H2, such as less than 5%, or less than 4%, or less than 3%, or less than 2%, or less than 1%, or substantially no hydrogen. The gas stream may also contain some CO2, such as about 1% to about 80% CO2 by volume or from 1% to about 30% _CO2 by volume. In one embodiment of the invention, the gas stream contains less than or about 20% CO ₂ by volume. In specific embodiments, the gas stream contains less than or about 15% CO2 by volume, less than or about 10% CO2 by volume, less than or about 5% CO2 by volume, or substantially no _CO2 .

A gas stream refers to any substrate stream that can be supplied, for example, from one module to another, from one module to a bioreactor, and/or from one module to a carbon capture device.

A reactant in this context refers to a substance that takes part and undergoes change during a chemical reaction. In specific embodiments, the reactants include, but are not limited to, CO and/or H2.

Microbial inhibitors as used herein refer to one or more components that slow down or interfere with a specific chemical reaction or other process, including microbial fermentation. In specific embodiments, microbial inhibitors include, but are not limited to, oxygen (O2), hydrogen cyanide (HCN), acetylene (C2H2), and BTEX (benzene, toluene, ethylbenzene, xylene).

Catalyst inhibitor, adsorbent inhibitor, etc. in this context, refer to one or more substances that reduce the rate or interfere with a desired chemical reaction. In specific embodiments, catalyst and/or adsorbent inhibitors may include, but are not limited to, hydrogen sulfide (H2S) and carbonyl sulfide (COS).

A removal module, a purification module, a processing module, and the like include technologies that are capable of converting and/or removing microbial inhibitors and/or catalyst inhibitors from a gas stream.

Terms components, impurities, etc. in this context refer to microbial inhibitors and/or catalyst inhibitors that may be present in the gas stream.

The term purified gas refers to a gas stream passed through at least one purification module and from which one or more components have been removed and/or converted.

The terms target level, target component level, and the like, as used herein, refer to the amount of one or more components that are considered acceptable in the gas stream. The predefined levels reported here were identified through microbial tolerance experiments.

The terms fermentable gaseous substrate, fermentable gas stream, and the like as used herein refer to a gas stream that contains a predetermined level of components and can be used as a carbon source by O-fixing microorganisms.

The term carbon capture in this context refers to the capture of carbon compounds, including CO ₂ and/or CO, from a stream containing CO ₂ and/or CO, and either:

- 4 043304 conversion of CO2 and/or CO into products; or converting CO2 and/or CO into substances suitable for long-term storage; or capture of CO ₂ and/or CO in substances suitable for long-term storage;

or a combination of these processes.

The term bioreactor includes a fermentation apparatus consisting of one or more vessels and/or towers or pipelines that include a continuous stirring reactor (CSTR), an immobilized cell reactor (ICR), a trickle bed reactor (TBR), a bubble column, a gas lift fermenter, a static mixer, a loop reactor, a membrane reactor such as a hollow fiber membrane bioreactor (HFM BR), or other vessel or other device suitable for contacting gas with liquid. The reactor is preferably adapted to produce a fermentable gas stream containing CO or CO2 or H2 or mixtures thereof. The reactor may contain several reactors (stages) located in parallel or in series. For example, the reactor may comprise a first growth reactor in which bacteria are grown, and a second fermentation reactor in which fermentation broth from the growth reactor can be fed and in which the bulk of the fermentation products can be produced.

Culture media or growth medium is used to describe the bacterial growth medium. Generally, the term refers to a medium containing nutrients and other components suitable for the growth of a culture of microorganisms. The term nutrient includes any substance that can be used in the metabolic pathway of a microorganism. Typical nutrients include potassium, B vitamins, trace metals and amino acids.

The term fermentation broth or broth covers a mixture of components including a culture medium and a culture or one or more microorganisms. It should be noted that the term microorganism and the term bacteria are used interchangeably throughout this document.

The term acid as used herein includes both carboxylic acids and their associated carboxylate anion, such as the mixture of free acetic acid and acetate present in the fermentation broth as described herein. The ratio of molecular acid to carboxylate in the fermentation broth depends on the pH of the system. In addition, the term acetate includes both an acetic acid salt and a mixture of molecular or free acetic acid and an acetic acid salt, such as the mixture of an acetic acid salt and a free acetic acid present in a fermentation broth as described herein.

The term acid gas in this context is a classification of gas that contains mixtures of components in quantities that make the gas acidic. Acid gas may contain large proportions of hydrogen sulfide (H2S) and/or carbon dioxide (CO2). In addition, the acid gas may contain some carbonyl sulfide (COS), hydrogen chloride (HCl), hydrogen fluoride (HF) and/or hydrogen cyanide (HCN).

The term required composition is used to indicate the required level and type of components in a substance, such as, for example, a gas stream. In particular, a gas is considered to have the required composition if it contains a certain component (for example, CO and/or CO2) and/or contains a certain component in a certain amount, and/or does not contain a certain component (for example, an impurity harmful to microorganisms ), and/or does not contain a certain component in a certain amount. More than one component may be considered when determining whether a gas stream has the desired composition. Preferably, the gas stream sent to the bioreactor is fermentable, i.e. has the required composition.

Unless the context otherwise requires, the expressions fermentation, fermentation process or fermentation reaction, etc. in this context include both the growth phase and the biosynthesis phase of the gaseous substrate.

A microorganism is a microscopic organism, such as a bacterium, archaea, virus or fungus. The microorganism of the present invention is usually a bacterium. In the context of this invention, the term microorganism should be considered to include the term bacterium.

The parent microorganism is the microorganism used to obtain the microorganism according to the present invention. The parent microorganism may be a naturally occurring microorganism (ie, a wild-type microorganism) or a microorganism that has been previously modified (ie, a mutant or recombinant microorganism). The microorganism of the present invention may be modified to express or overexpress one or more enzymes not expressed or overexpressed in the parent microorganism. Likewise, a microorganism of the invention may be modified to contain one or more genes that were not contained in the parent microorganism. The microorganism of the invention may also be modified not to express or to express lower amounts of one or more enzymes that were expressed in the parent microorganism. In one embodiment of the invention, the parent microorganism is Clostridium autoethanogenum,

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Clostridium ljungdahlii or Clostridium ragsdalei. In a preferred embodiment, the parent microorganism is Clostridium autoethanogenum LZ1561, deposited on June 7, 2010 in the German Bank for Microorganisms and Cell Cultures (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, DSMZ), located at Inoffenstrasse 7B, D-38124 Braunschweig, Germany , in accordance with the terms of the Budapest Treaty and with the assignment of registration number DSM23693. This strain is described in international patent application No. PCT/NZ 2011/000144, published as WO 2012/015317.

The term is derived from meaning that a nucleic acid, protein or microorganism is modified or adapted from another (i.e. parent or wild type) nucleic acid, protein or microorganism to form a new nucleic acid, protein or microorganism. Such modifications or adaptations typically include insertion, deletion, mutation or substitution of nucleic acids or genes. Typically, the microorganism of the present invention is derived from a parent microorganism. In one embodiment, the microorganism of the present invention is derived from Clostridium autoethanogenum, Clostridium ljungdahlii, or Clostridium ragsdalei. In a preferred embodiment, the microorganism of the present invention is derived from Clostridium autoethanogenum LZ1561, which is deposited under DSMZ accession number DSM23693.

Wood-Ljungdahl refers to the described Wood-Ljungdahl carbon fixation pathway, such as Ragsdale, Biochim Biophys Acta, 1784: 1873-1898, 2008. Wood-Ljungdahl microorganisms, as expected, refer to microorganisms containing the Wood-Ljungdahl pathway. Typically, the microorganism of the present invention contains the native Wood-Ljungdahl pathway. In this context, the Wood-Ljungdahl cascade may be the native, unmodified Wood-Ljungdahl cascade, or it may be the Wood-Ljungdahl cascade with some degree of genetic modification (i.e. overexpression, heterologous expression, knockout, etc.), provided that it still functions to convert CO, CO ₂ and/or H ₂ to acetyl-CoA. Ш refers to a molecule containing one carbon atom, such as CO, CO ₂ , CH4 or CH3OH. d-oxygenate refers to a one-carbon molecule that also contains at least one oxygen atom, such as CO, CO2 or CH3OH. A C1 carbon source refers to a one-carbon molecule that serves as a partial or sole carbon source for the microorganism of the present invention. For example, the d-carbon source may contain one or more compounds selected from: CO, CO ₂ , CH ₄ , CH3OH or CH2O2. The d-carbon source preferably contains one or more compounds selected from: CO and CO ₂ . A d-fixing microorganism is a microorganism capable of producing one or more products from a d-carbon source. Typically, the microorganism of the present invention is a d-fixing bacterium.

An anaerobe is a microorganism that does not require oxygen to grow. An anaerobe can react negatively or even die in the presence of oxygen above a certain threshold. However, some anaerobes are able to tolerate low levels of oxygen (eg, 0.000001-5% oxygen). Typically, the microorganism of the present invention is an anaerobic.

Acetogens are obligate anaerobic bacteria using the Wood-Ljungdahl pathway as their main mechanism for energy conservation and the synthesis of acetyl-CoA and acetyl-CoA-derived products such as acetate (Ragsdale, Biochim Biophys Acta, 1784: 1873-1898, 2008 ). Specifically, acetogens use the Wood-Ljungdahl pathway as (1) a mechanism for the reductive synthesis of acetyl-CoA from CO2, (2) a terminal electron-withdrawing, energy-saving process, (3) a mechanism for fixing (assimilation) CO2 during cellular carbon synthesis (Drake, Acetogenic Prokaryotes, In: The Prokaryotes, ^3rd edition, p. 354, New York, NY, 2006). All naturally occurring acetogens are d-fixing, anaerobic, autotrophic, and non-methanotrophic organisms. Typically, the microorganism of the present invention is an acetogen.

An ethanologen is a microorganism that produces or is capable of producing ethanol. Typically, the microorganism of the present invention is an ethanologen.

An autotroph is a microorganism that can grow in the absence of organic carbon. Instead, autotrophs use inorganic carbon sources such as CO and/or CO ₂ . Generally, the microorganism of the present invention is an autotroph.

A carboxydotroph is a microorganism capable of using CO as its sole source of carbon and energy. Typically, the microorganism of the present invention is a carboxydotroph.

A methanotroph is a microorganism capable of using methane as its sole source of carbon and energy. In certain embodiments, the microorganism of the invention is a methanotroph, or is derived from a methanotroph. In other embodiments, the microorganism of the invention is not a methanotroph or is not derived from a methanotroph.

Substrate refers to a source of carbon and/or energy for a microorganism according to this

- 6 043304 invention. Typically the substrate is gaseous and contains a source of Cl-carbon, such as CO,

CO2 and/or CH4. The substrate preferably contains a source of O-carbon in the form of CO or CO + CO2. The substrate may additionally contain other non-carbon components, such as H2, N2 or electrons.

The term co-substrate refers to a substance that, although not necessarily the primary source of energy and material for the synthesis of a product, can be used to synthesize a product when added to another substrate, such as a primary substrate.

The substrate and/or source of O-carbon may be a waste gas obtained as a by-product of an industrial process or from some other source such as automobile exhaust or biomass gasification. In certain embodiments, the industrial process is selected from the group consisting of: ferrous metal product manufacturing, such as steel production, non-ferrous metal product manufacturing, petroleum refining, coal gasification, power generation, carbon black production, ammonia production, methanol production, and coke production . In such embodiments, the substrate and/or source of O-carbon can be recovered from the industrial process before being released into the atmosphere using any convenient method.

The substrate and/or source of O-carbon can be obtained from several sources, for example from industrial processes, including gas released from carbohydrate fermentation, gas fermentation, gas released from cement production, pulp and paper production, steel production, petroleum refining and related processes, petrochemical production, coke production, anaerobic or aerobic digestion, synthesis gas (derived from sources including, but not limited to, biomass, liquid waste streams, solid waste streams, municipal streams, fossil resources including natural gas, coal and petroleum), natural gas extraction, petroleum extraction, metallurgical processes, production and/or refining of aluminum, copper and/or ferroalloys, from geological reservoirs and catalytic processes (derived from steam sources, including, but not limited to, steam methane reforming, steam reforming of oil, gasification of petroleum coke, catalyst regeneration - liquid cracking, catalyst regeneration - oil reforming, and dry methane reforming). In certain cases, the substrate and/or source of d-carbon can be obtained from a combination of two or more sources.

Substrate composition can have a significant impact on the efficiency and/or cost of the reaction. For example, the presence of oxygen (O2) can reduce the efficiency of the anaerobic fermentation process. Depending on the composition of the substrate, it may be desirable to treat, purify, or filter the substrate to remove any undesirable contaminants, such as toxins, unwanted components, microbial inhibitors, or dust particles, and/or to increase the concentration of desired components.

In some embodiments, the fermentation is performed in the absence of carbohydrate substrates, such as sugar, starch, lignin, cellulose, or hemicellulose.

The microorganism of the present invention can be cultured with a gas flow to obtain one or more products. Thus, for example, the microorganism according to this invention can produce or can be genetically engineered to produce ethanol (WO 2007/117157), acetate (WO 2007/117157), butanol (WO 2008/115080 and WO 2012/053905), butyrate (WO 2008 /115080), 2,3-butanediol (WO 2009/151342 and WO 2016/094334), lactate (WO 2011/112103), butene (WO 2012/024522), butadiene (WO 2012/024522), methyl ethyl ketone (2-butanone ) (WO 2012/024522 and WO 2013/185123), ethylene (WO 2012/026833), acetone (WO 2012/115527), isopropanol (WO 2012/115527), lipids (WO 2013/036147), 3-hydroxypropionate (3 -HP) (WO 2013/180581), isoprene (WO 2013/180584), fatty acids (WO 2013/191567), 2-butanol (WO 2013/185123), 1,2-propanediol (WO 2014/036152), 1 -propanol (WO 2014/0369152), products derived from chorismate (WO 2016/191625), 3-hydroxybutyrate (WO 2017/066498) and 1,3-butanediol (WO 2017/0066498). In addition to one or more target products, the microorganism of the present invention can also produce ethanol, acetate and/or 2,3-butanediol. In some embodiments of the invention, the microbial biomass itself can be considered a product. The one or more products may be further converted to produce at least one component of diesel fuel, jet fuel and/or gasoline.

A native product is a product produced by a non-genetically modified microorganism. For example, ethanol, acetate and 2,3-butanediol are native products of Clostridium autoethanogenum, Clostridium ljungdahlii and Clostridium ragsdalei. A non-native product is a product produced by a genetically modified microorganism, but not produced by the non-genetically modified microorganism from which the genetically modified microorganism is derived.

Selectivity refers to the ratio of the production of the target product to the production of all fermentation products produced by the microorganism. The microorganism of the invention can be engineered to produce products with a certain selectivity or with minimal selectivity. In one embodiment of the invention, the target product is at least

- 7 043304 about 5%, 10%, 15%, 20%, 30%, 50% or 75% of all fermentation products produced by the microorganism according to the present invention. In one embodiment, the target product constitutes at least 10% of the total fermentation products produced by the microorganism of the present invention, such that the microorganism of the present invention has a selectivity for the target product of at least 10%. In yet another embodiment, the target product constitutes at least 30% of the total fermentation products produced by the microorganism of the present invention, such that the microorganism of the present invention has at least 30% selectivity for the target product.

Typically, cultivation is carried out in a bioreactor. The term bioreactor includes a culture/fermentation apparatus consisting of one or more vessels, columns or piping, e.g. continuous stirred tank reactor (CSTR), immobilized cell reactor (ICR), trickled bed reactor (TBR). ), bubble column, gas lift fermenter, static mixer, or other vessel or other device suitable for bringing gas into contact with liquid. In some embodiments, the bioreactor may comprise a first growth reactor and a second culture/fermentation reactor. The substrate can be fed into one or both of these reactors. Throughout this document, the terms cultivation and fermentation are used interchangeably. These terms cover both the growth phase and the biosynthesis phase of the product during the cultivation/fermentation process.

Cultivation is typically maintained in an aqueous culture medium containing nutrients, vitamins and/or minerals sufficient to support growth of the microorganism. The aqueous culture medium is preferably an anaerobic microbial growth medium, such as a minimal anaerobic microbial growth medium. Suitable media are well known in the art.

To obtain the target product, cultivation/fermentation is preferably carried out under appropriate conditions. Typically, cultivation/fermentation is performed under anaerobic conditions. Reaction conditions to consider include pressure (or partial pressure), temperature, gas flow rate, liquid flow rate, pH of the medium, redox potential of the medium, stirring speed (if using a continuous mechanically stirred reactor), inoculum level, maximum gaseous substrate concentrations so that the gas content in the liquid phase does not become limiting, and maximum product concentrations to avoid production inhibition. In particular, the rate of substrate introduction can be controlled to ensure that the gas concentration in the liquid phase does not become a limiting factor, since under gas-limited conditions the crop can consume products.

Operating a bioreactor at elevated pressures makes it possible to increase the rate of gas mass transfer from the gas phase to the liquid phase. Accordingly, it is generally preferable to carry out the cultivation/fermentation at a pressure above atmospheric pressure. Additionally, since a given gas conversion rate is dependent in part on substrate retention time, and retention time determines the required bioreactor volume, the use of pressurized systems can significantly reduce the required bioreactor volume and therefore the capital cost of culture/fermentation equipment. This in turn means that residence time, defined as the volume of liquid in the bioreactor divided by the gas flow rate, can be reduced if bioreactors are maintained at elevated pressure rather than atmospheric pressure. Optimal reaction conditions will depend in part on the specific microorganism used. However, in general it is preferable to carry out fermentation at pressures above atmospheric pressure. Additionally, since the target gas conversion rate depends in part on the substrate retention time, and achieving the desired retention time in turn dictates the required bioreactor volume, the use of pressurized systems can significantly reduce the required bioreactor volume and therefore the capital cost of culture equipment /fermentation.

The target products can be separated or purified from the fermentation medium by any method or combination of methods known in the art, including, for example, fractional distillation, evaporation, permeable membrane evaporation, gas stripping, phase separation and extractive fermentation, including, for example, liquid-liquid fermentation. liquid extraction. In some embodiments, the target products are isolated from the fermentation medium by continuously partially removing the medium from the bioreactor, separating microbial cells from the medium (typically by filtration), and recovering one or more target products from the medium. Alcohols and/or acetone can be isolated, for example, by distillation. Acids can be isolated, for example, by adsorption on activated charcoal. The separated microbial cells are preferably returned to the bioreactor. The cell-free permeate remaining after removal of the target products is also preferably returned to the bioreactor. Additional nutrients (such as B vitamins) can be added to the cell-free filtrate to replenish the media before it is returned to the bioreactor.

- 8 043304

Description

The inventors have discovered that by combining different modules together in a specific order, the various gas components can be gradually converted and/or removed from the gas stream, whereby if components may have a detrimental effect on subsequent modules, they are removed and/or converted upstream. stream from these modules, allowing subsequent steps to remove other components of the gas and then provide the fermentable gas stream to a bioreactor where the gas can be processed by gas-fermenting microorganisms to create useful products. The conversion and/or removal of these components is achieved without consuming the required compounds and without creating other unwanted compounds. In certain embodiments of the invention, the fermentable gas stream may be supplied to a carbon capture device for storage.

In specific embodiments of the invention, the gas stream is sequentially supplied to the following processing modules: (1) hydrolysis; (2) acid gas removal; (3) catalytic hydrogenation; and (4) deoxygenation. The order of gas passage is critical to the successful production of a fermentable gas stream. Each module is used to remove and/or convert one or more components in a gas stream.

Hydrolysis module

Hydrogen cyanide (HCN) and carbonyl sulfide (COS) are two putative components that must first be brought into contact with water before they can be effectively removed from the gas stream. The inventors have discovered that in applications where a high sulfur content gas stream is used, conversion of COS to hydrogen sulfide (H ₂ S) may be necessary because many commercial processes cannot effectively remove sulfur in the form of COS. This transformation occurs according to the following reaction:

COS + H ₂ O ~ H ₂ S + CO ₂

This conversion can be achieved using any technology capable of converting COS to H ₂ S. In various embodiments of the invention, a metal oxide catalyst is used in the hydrolysis module to perform the conversion. In particular embodiments of the invention, alumina is used to perform the conversion.

In certain embodiments, the hydrolysis step may include a multilayer approach to convert COS and remove H ₂ S. In certain embodiments, the first layer is a conversion layer whereby COS is converted to H ₂ S. An example of such a conversion layer is BASF SELEXSORB™ COS . In certain embodiments, the second layer is an iron-based adsorbent, such as a non-hazardous high-area granular material sold under the trade name AxTrap 4001, which removes H2S.

In specific embodiments of the invention, the gas stream is supplied to a hydrolysis module to convert and/or remove one or more components from the gas stream. In some cases, the gas stream after hydrolysis significantly reduces the content of at least one component selected from the group consisting of: COS and/or HCN.

Acid gas removal module

Acid gas removal refers to the process by which hydrogen sulfide (H2S) and/or carbon dioxide (CO ₂ ), as well as other acid gases, are separated from a gas stream.

In some cases, the acid gas removal module uses a zinc oxide (ZnO) catalyst to remove hydrogen sulfide (H2S) from the gas stream.

In particular embodiments of the invention, pressure swing adsorption (PSA) is used as the acid gas removal module. In certain embodiments of the invention, pressure swing adsorption will not reduce the level of each component to the required levels, and therefore subsequent steps may be required. In particular embodiments of the invention, a hydrocarbon removal layer is used prior to pressure swing adsorption to remove one or more components, including BTEX.

Pressure swing adsorption is an adiabatic process that can be used to purify gases of associated impurities by adsorption onto suitable adsorbents in fixed beds contained in high-pressure vessels. Regeneration of adsorbents is carried out by countercurrent depressurization and purging at low pressure with previously restored purified gas. To obtain a continuous flow of product, preferably at least two adsorbers are provided, wherein at least one adsorber receives, purifies and directs the stream of purified gas to additional purification modules and at least one adsorber is used to perform regeneration of one or several adsorbers that direct the flow of purified gas to additional purification modules. Conventional adsorbents can be easily selected by one skilled in the art depending on the type of impurity that needs to be adsorbed and removed. Suitable adsorbents include zeolite molecular sieves, activated carbon, silica gel or activated alumina. Combinations of absorbent layers can be used on top of each other, thereby dividing the contents of the adsorber into several separate zones.

- 9 043304

Pressure swing adsorption involves oscillatory changes in parameters such as pressure, temperature, flow and composition of the gaseous and adsorbed phases. Gas purification or separation using PSA typically occurs at temperatures close to the ambient temperature of the feed gas, causing the components to be removed to be selectively adsorbed. Adsorption should ideally be sufficiently reversible to allow regeneration of adsorbents at similar ambient temperatures. In addition, adsorption should preferably be carried out in such a way as to prevent or at least minimize the formation of undesired compounds.

In embodiments of the invention in which subsequent steps are used for acid gas removal, a carbon dioxide adsorption module or an additional acid gas removal module may be used after the PSA module. A carbon dioxide adsorption module is used to remove carbon dioxide (CO2) from a purified gas stream to bring carbon dioxide levels within the required range. In these embodiments, the purified gas from the PSA module can be sent to the carbon dioxide adsorption module before being supplied to the catalytic hydrogenation module. In embodiments that bypass the catalytic hydrogenation module, or in embodiments that do not include a catalytic hydrogenation module, purified gas from the PSA module can be sent directly to the deoxygenation module.

In particular embodiments of the invention, the gas stream is supplied to an acid gas removal module to convert and/or remove one or more components from the gas stream. In some cases, at least one component selected from the group consisting of carbon dioxide (CO2), hydrogen sulfide (H2S) and hydrogen cyanide (HCN) is removed from the low acid gas stream.

Catalytic hydrogenation module

Acetylene (C2H2) acts as an inhibitor of microorganisms. A catalytic hydrogenation module can be used to remove acetylene. Catalytic hydrogenation is the treatment with hydrogen in the presence of a catalyst such as, but not limited to, nickel, palladium or platinum. There is no single universal catalyst suitable for acetylene hydrogenation. The choice of catalyst largely depends on the gas composition and operating conditions. In particular embodiments of the invention, palladium is used as a catalyst. In specific embodiments of the invention, palladium on alumina (Pd/Al2O ₃ ) is used as a catalyst. An example of such catalysts is BASF™ R 0-20/47.

Inhibitors reduce the activity of palladium. Sulfur compounds are potential palladium inhibitors. Compounds such as hydrogen sulfide (H ₂ S) or carbonyl sulfide (COS) adsorb to palladium and can change reaction sites. In specific embodiments, known palladium inhibitors are removed and/or converted prior to the catalytic hydrogenation step.

In certain embodiments of the invention, a catalytic hydrogenation module may not be required for acetylene removal. In addition to removal by the catalytic hydrogenation module, acetylene can be removed from the gas stream by some deoxygenation modules. In particular embodiments of the invention in which the catalytic hydrogenation module is unnecessary, the catalytic hydrogenation module can be bypassed and/or not included in the process. An example of when a catalytic hydrogenation module is not required if acetylene levels are low enough that it can be effectively removed by other modules. In particular embodiments of the invention, where acetylene levels are sufficiently low, the gas stream can be passed from the acid gas removal module to the deoxygenation module, bypassing the catalytic hydrogenation module.

In specific embodiments of the invention, the gas stream is supplied to a catalytic hydrogenation module to convert and/or remove one or more components from the gas stream. In some cases, the hydrogenation stream has a low content of at least acetylene (C2H2).

Deoxygenation module

Oxygen (O2) is an inhibitor of microorganisms. Consequently, oxygen in the gas stream must be reduced to acceptable levels. A deoxygenation module can be used to reduce the oxygen level in the gas stream. Reducing oxygen levels can be achieved by any suitable means. In particular embodiments of the invention, the deoxygenation module uses a catalytic process whereby oxygen (O ₂ ) is reduced to either carbon dioxide (CO ₂ ) or water (H ₂ O). In certain embodiments of the invention, the catalyst used in the deoxygenation module contains copper. An example of such a catalyst is BASF PURISTAR™ R 3.15 or BASF CU 0226S.

In specific embodiments of the invention, the deoxygenation module can be used to effectively reduce the level of acetylene in the gas stream, thereby bypassing the catalytic hydrogenation step. One significant difference between acetylene removal by the catalytic hydrogenation module and the deoxygenation module is the production of ethane (C2H6). When removing acetyl

- 10 043304 lena, the deoxygenation module produces more ethane than when acetylene is removed by the catalytic hydrogenation module. However, due to the strong natural resistance of the microorganism used in the gas fermentation process, the inventors discovered that the level of ethane produced in the deoxygenation module did not have a detrimental effect on the microorganism, and thus, in certain embodiments of the invention, the catalytic hydrogenation module could be bypassed .

Another significant difference between the catalytic hydrogenation module and the deoxygenation module is the production of methanol (CH ₃ OH). Methanol can be produced using any copper-based deoxygenation module. When a copper deoxygenation module is used to remove acetylene, the purification process produces more methanol compared to a purification process using a catalytic hydrogenation module. However, due to the strong natural resistance of the microorganism used in the subsequent gas fermentation process, the inventors discovered that the level of methanol formed in the deoxygenation module did not have a detrimental effect on the microorganism, and thus, in certain embodiments of the invention, the catalytic hydrogenation module could be bypassed .

In addition to the above components, some deoxygenation modules can be used to effectively remove mercury (Hg). Not all gas streams will contain mercury (Hg). However, the purification process is designed to effectively treat gas streams from a range of sources, some of which may contain mercury (Hg). Therefore, in some cases where the gas stream contains mercury (Hg), a deoxygenation module can be used to effectively remove mercury (Hg) from the gas stream. If mercury (Hg) is removed from a gas stream using a deoxygenation module, the deoxygenation stream may not contain mercury (Hg).

In specific embodiments of the invention, the gas stream is supplied to a deoxygenation module to convert and/or remove one or more components from the gas stream. In some cases, the deoxygenation stream has a low content of at least oxygen (O2) and/or acetylene (C2H2). In various cases, the deoxygenation stream has a low content of mercury (Hg) in addition to oxygen (O2) and/or acetylene (C2H2).

Gas sampling and analysis system

Reliable analytical monitoring and control technology may be required to control, maintain and optimize the process. Such tools may include, but are not limited to, a gas sampling system and logging/reporting software.

Analysis of the composition of the gas stream is the most important element of gas preparation.

Gas stream analysis is required to measure the content and determine the components that must be converted and/or removed from the gas stream. To ensure that the gas stream has the desired composition, it may be necessary to measure components in the gas stream at numerous points. These measurements can be carried out using any suitable means, which may include an automatic online monitoring system, and can be carried out in a continuous and/or periodic manner. In specific embodiments of the invention, measurement of the gas flow may be performed before and/or after it is supplied to the various purification modules.

In specific embodiments of the invention, the gas flow is measured before it is supplied to one or more purification modules. In some cases, measuring the components present in the gas stream before it enters one or more treatment modules determines which treatment modules will be used. In particular embodiments of the invention, determining whether or not to use a hydrolysis module depends, at least in part, on measuring the carbonyl sulfide (COS) content present in the gas stream. In particular embodiments of the invention, determining whether or not to use a catalytic hydrogenation module depends, at least in part, on measuring the acetylene (C2H2) content of the gas stream. In particular embodiments of the invention, determining whether a hydrogen cyanide removal module should be used depends, at least in part, on measuring the amount of hydrogen cyanide (HCN) present in the gas stream.

The content of components in the gas stream can vary depending on many factors. In some embodiments of the invention, the content of components in the gas stream varies depending on the source from which the gas stream is obtained. For example, gas streams obtained from a gasification process may have different levels of components depending on the material fed to the gasifier. In certain embodiments of the invention, the content of components in the gas stream varies depending on the technological operations in the gasifier. For example, gas streams obtained from gasification processes may have different levels of components if a blockage occurs in the gasifier.

In specific cases, a gas stream is obtained by mixing streams from two or more sources. In various embodiments of the invention, the composition of the gas stream can be measured before, during and/or after mixing the source streams.

In specific cases, the gas stream may be purified before, during and/or after mixing according to

- 11 043304 currents from sources. In certain cases, the composition of the gas stream is measured in order to analyze and determine which cleaning modules are needed. This determination may be based, at least in part, on one or more components present in the gas stream. In at least one case, the composition of these gases may change over time, resulting in different component contents. These fluctuations can affect the performance of the cleaning process. Thus, adjustments to the purification process may be necessary in response to changes in composition. In various cases, this cleaning process adjustment involves removing, bypassing, and/or adding one or more cleaning modules. The choice of which cleaning module to remove, bypass, and/or add may be determined, at least in part, by the presence of a particular component. In certain cases, one or more components, not previously present or present but in quantities below detection levels, may be measured later, which may then require the addition of one or more purification modules. In some cases, increasing the carbonyl sulfide (COS) and/or hydrogen cyanide (HCN) content may require the addition of a hydrolysis module, while decreasing the carbonyl sulfide (COS) and/or hydrogen cyanide (HCN) content may require the removal of the hydrolysis module. In some cases, increasing levels of carbon dioxide (CO2), hydrogen sulfide (H2S) and/or hydrogen cyanide (HCN) may require the addition of an acid gas removal module, while decreasing carbon dioxide ( _CO2 ), hydrogen sulfide ( _H2) S) and/or hydrogen cyanide (HCN) can be removed from the acid gas removal module. In some cases, increasing the acetylene (C ₂ H ₂ ) content may require the addition of a catalytic hydrogenation module, while decreasing the acetylene (C2H2) content may require the removal of the catalytic hydrogenation module. In some cases, increasing oxygen (O2) and/or acetylene (C2H2) may require adding a deoxygenation module, while decreasing oxygen (O2) and/or acetylene (C2H2) may require removing the deoxygenation module.

For on-line measurement, each measuring point can be connected to a steel pipe to facilitate the transmission of gas flow through the control device. In specific embodiments of the invention, the gas flow is controlled by a pumping device to supply the pressurized gas flow to the measuring device. In particular embodiments of the invention, the gas stream is at a pressure of from twenty to thirty pounds per square inch (138-207 kPa). In specific embodiments of the invention, different measuring devices are used to measure the content of different components.

In specific embodiments of the invention, the levels of C2H2 and HCN in the gas stream are monitored by a spectrometer. In some cases, the spectrometer will monitor the level of one or more components (NH ₃ , CO ₂ and/or H ₂ S) in addition to C ₂ H ₂ and/or HCN. In specific embodiments of the invention, the spectrometer is configured to measure at various sampling points in periodic increments.

In specific embodiments of the invention, the content of hydrocarbons, BTEX, naphthalene and oxygenates of dimethyl ether, diethyl ether, acetaldehyde, tetrahydrofuran, methyl ethyl ketone, acetone, methanol and ethanol is measured by a gas chromatograph. In specific embodiments of the invention, the chromatograph is configured to measure at various sampling points in periodic increments.

In particular embodiments of the invention, the nitrogen and sulfur content of the gas stream is measured by a device that includes ultraviolet fluorescence (UVF) oxidative pyrolysis technology and chemiluminescence technology. In specific embodiments of the invention, the device is configured to measure at various sampling points in periodic increments.

In particular embodiments of the invention, large and/or trace amounts of components in the gas stream are measured by a gas chromatograph. Components contained in large and/or trace amounts include, but are not limited to, hydrogen, nitrogen, oxygen, methane, carbon monoxide, carbon dioxide and hydrogen sulfide. In specific embodiments of the invention, the device is configured to measure at various sampling points in periodic increments.

In specific embodiments of the invention, various measurement devices may be connected to a software application through which data collected by the measurement devices is interpreted and stored in a database. In certain embodiments of the invention, the data is converted into an easily interpretable format, such as a spreadsheet.

Special catalyst

The inventors have discovered that by using only a specialized catalyst containing copper supported on alumina, a fermentable gas stream can be successfully produced from a variety of gas sources. Such gas may be produced in whole or in part from a combination of gas from one or more industrial processes, synthesis gas and/or producer gas. In particular, this special catalyst was found to be capable of reducing oxygen, acetylene and hydrogen cyanide with less than 100 ppm oxygen, less than 1 ppm acetylene and less than 1 ppm hydrogen cyanide. ppm in the fermentable gas stream. In various cases, copper (I) is used as a catalyst. In various cases, the copper used for this catalyst was reduced copper.

While purifying a high sulfur feed gas, the inventors discovered that a fermentable gas stream was successfully produced using a sulfided version of the custom catalyst. This sulfidation was accomplished by passing a gas containing a sulfidation reagent through a reduced version of the catalyst. Such reduction and sulfidation can be carried out in accordance with the prior art. In one embodiment of the invention, sulfidation results in the formation of sulfided copper(I) on an alumina supported catalyst. In one embodiment of the invention, sulfidation results in the formation of sulfided copper(II) on an alumina supported catalyst. A sulfided copper catalyst may be particularly useful in reducing mercury (Hg) levels if present in a gas stream, as copper sulfide is known to be an effective mercury adsorbent.

General information

In specific embodiments of the invention, the fermentable gas stream is supplied to a bioreactor containing d-fixing microorganisms. These d-fixing microorganisms are capable of converting the d-containing gas stream into useful chemicals and products through gaseous fermentation. To provide a non-inhibitory fermentation gas stream into the bioreactor, the gas stream must contain a predetermined level of components. In specific embodiments, the components of interest include oxygen (O2), hydrogen cyanide (HCN), acetylene (C ₂ H ₂ ), BTEX (benzene, toluene, ethylbenzene, xylene) and sulfur compounds (H2S and COS). In various embodiments, the oxygen (O2) level must be less than one hundred parts per million (100 ppm) to be at the desired level. In various embodiments of the invention, the level of hydrogen cyanide (HCN) must be less than one part per million (1 ppm) to be at a specified level. Preferably, the hydrogen cyanide (HCN) level must be less than one hundred parts per billion (100 ppb) to be at the specified level. In various embodiments, the level of acetylene (C ₂ H ₂ ) must be less than one part per million (1 ppm) to be at the desired level. In various embodiments of the invention, the BTEX level must be less than thirty parts per million (30 ppm) to be at the target level. In various embodiments of the invention, the level of sulfur compounds (H ₂ S and COS) must be less than one part per million (1 ppm) to be at a given level. In particular embodiments of the invention, the amounts of all components must be at their predetermined levels to constitute the predetermined level of components.

The system can include additional modules both before the hydrolysis module and after the deoxygenation module. These optional modules may include, but are not limited to, a solids removal module, a chloride removal module, a tar removal module, a hydrogen cyanide removal module, and an optional acid gas removal module that can remove organic compounds. In certain cases, a module containing activated carbon is used to remove unwanted organic compounds. These organic compounds may, in certain cases, be produced by one or more purification modules. In specific embodiments of the invention, gas is supplied to the system to modules in the following sequence: (1) solids removal module, (2) chloride removal module, (3) tar removal module, (4) hydrolysis module, (5) acid gas removal module , (5) catalytic hydrogenation module, (6) deoxygenation module, (7) hydrogen cyanide removal module, and (8) optional acid gas removal module.

The solids removal module may comprise any suitable module capable of removing solids from a gas stream. Particulate matter is usually associated with line blockage. To prevent line clogging, a solids removal module can be used. In specific embodiments of the invention, the particulate removal module is a bag filter. The bag filter may be of any suitable type, including, but not limited to, mechanical agitation, pulse purge, and backflush. In certain embodiments of the invention, a solids removal module is used before other modules.

The chloride removal module may comprise any suitable module capable of removing chlorides from a gas stream. Chlorides are commonly associated with corrosion in gas purification processes. To prevent corrosion, a chloride removal module can be used. In specific embodiments of the invention, the chloride removal module is an alkaline scrubber capable of removing hydrogen chloride (HCl). In specific embodiments of the invention, the chloride removal module is a cyclone capable of removing ammonium chloride (NH ₄ Cl).

The tar removal module may comprise any suitable module capable of removing tar from a gas stream. Resins may include, but are not limited to, a heavy hydrocarbon such as naphthalene, which is commonly associated with line plugging. To avoid line blockage, a resin removal module can be used. In specific embodiments of the invention, the removal module

- 13 043304 resins is an adsorption device. In certain cases, the adsorption device contains activated carbon.

The hydrogen cyanide removal module may comprise any suitable module capable of removing hydrogen cyanide from a gas stream. Hydrogen cyanide is generally related to the inhibition of microorganisms. To prevent inhibition of microorganisms, a hydrogen cyanide removal module can be used. In specific embodiments of the invention, the hydrogen cyanide removal module is a copper-treated activated carbon device.

The optional acid gas removal module may comprise any suitable module capable of removing carbon dioxide from the gas stream. High levels of carbon dioxide can dilute the gas stream, requiring large bioreactors and/or additional fermentation lines. To prevent carbon dioxide from diluting the gas stream, an optional acid gas removal module can be used. In specific embodiments of the invention, the optional acid gas removal module is a PSA module, which may use calcium hydroxide.

The system may include one or more temperature modules to increase or decrease the temperature of the gas stream. These temperature modules can be placed before and/or after other modules to increase or decrease the temperature of the gas stream between the modules. The temperature modules may comprise any suitable module capable of increasing or decreasing the temperature of the gas stream. In specific embodiments of the invention, the temperature modules are shell-and-tube heat exchangers. A shell-and-tube heat exchanger consists of a chamber with a bundle of tubes inside a shell. A shell-and-tube heat exchanger is capable of controlling the temperature of a gas stream by passing a liquid, such as water, through a chamber while simultaneously passing the gas stream through a bundle of tubes. Heat from the gas flow to the liquid is transferred through the walls of the tubes.

The system may include pressure modules to increase or decrease the pressure of the gas stream. These pressure modules can be placed before and/or after other modules. The pressure modules may comprise any suitable module capable of increasing or decreasing the pressure of the gas stream. In specific embodiments of the invention, the pressure module is a compressor. The compressor is capable of increasing the pressure of the gas stream to a value that is suitable for transferring the gas stream. In specific embodiments of the invention, the pressure module is a valve. The valve is capable of reducing the pressure of the gas stream to a value that is suitable for transfer of the gas stream.

In fig. 1 shows a system for selectively filtering components from a gas stream, the system comprising a hydrolysis module 120, an acid gas removal module 130, a deoxygenation module 140, and a bioreactor 150. The gas stream can be obtained from any source of industrial, reactor and/or synthesis gas 110 A gas stream is supplied from the industrial, reactor and/or synthesis gas source 110 through conduit 112 to a hydrolysis module 120 to convert at least one component in the gas stream to produce a post-hydrolysis gas stream. The hydrolysis gas stream passes through conduit 122 to an acid gas removal module 130. The acid gas removal module 130 removes at least one component 134 from the hydrolysis gas stream to produce a low acid gas content gas stream. The low acid gas stream passes through conduit 132 to a deoxygenation module 140. The deoxygenation module 140 removes at least one component 144 from the low acid gas gas stream to produce a deoxygenation gas stream. At least a portion of the gas stream after deoxygenation can be supplied through line 142 to bioreactor 150 for fermentation. Preferably, the bioreactor contains C1-fixing microorganisms capable of producing products 154 and a gaseous substrate from the gas stream after fermentation.

At least a portion of the gaseous substrate after fermentation can be returned to one or more purification modules. In some cases, the post-fermentation substrate gas is supplied through conduit 152 to a hydrolysis module 120 to convert one or more components in the post-fermentation substrate gas. In some cases, the gaseous substrate after fermentation can be stored in a carbon capture device.

The inventors have discovered that by configuring the various modules in a specific sequence, the gas stream supplied to the bioreactor 150 contains a predetermined level of components to be fermented by O-fixing microorganisms, without significant consumption of the desired compounds and without producing additional inhibitory compounds. It has been found that the hydrolysis module 120 is capable of converting at least a portion of the carbonyl sulfide (COS) present in the gas stream into hydrogen sulfide (H ₂ S). It has also been discovered that at least one or more of the components removed by the acid gas removal module 130 include carbon dioxide (CO2) and hydrogen sulfide (H2S). By installing the hydrolysis module 120 upstream of the acid gas removal module 130, at least a portion of the carbonyl sulfide (COS) converted to hydrogen sulfide (H2S) can be removed from the gas stream by the acid gas removal module 130.

In addition, it was discovered that various modules may not be needed due to the level of components present in the gas stream. In fig. 2 illustrates a system for selectively filtering components from a gas stream, wherein the gas stream can be directed to bypass the hydrolysis module 220. In particular embodiments of the invention, the level of components can be effectively reduced without passing through specific modules. In some cases, the hydrolysis module 220 is eliminated from the process. By bypassing the hydrolysis module 220, the gas stream from the industrial, generator and/or synthetic gas source 210 is supplied via conduit 212 to the acid gas removal module 230. The acid gas removal module 230 removes at least one component 234 from the gas stream to produce flow with low acid gas content. The low acid gas stream passes through conduit 232 to a deoxygenation module 240. The deoxygenation module 240 removes at least one component 244 from the low acid gas stream to produce a deoxygenation gas stream. At least a portion of the gas stream after deoxygenation can be supplied through line 242 to bioreactor 250 for fermentation. Preferably, the bioreactor contains C1-fixing microorganisms capable of producing products 254 and a gaseous substrate from the gas stream after fermentation.

At least a portion of the gaseous substrate after fermentation can be returned to one or more purification modules. In some cases, the post-fermentation substrate gas is supplied through conduit 252 to a hydrolysis module 220 to convert one or more components in the post-fermentation substrate gas. In embodiments of the invention that bypass the hydrolysis module 220, the post-fermentation substrate gas may be supplied via conduit 252 to the acid gas removal module 230 to remove at least one component 234 from the post-fermentation substrate gas. In some cases, the gaseous substrate after fermentation can be stored in a carbon capture device.

Certain gas streams have component levels that may require additional modules. In fig. 3 illustrates a system for selectively filtering components from a gas stream, further including a catalytic hydrogenation module 360 before a deoxygenation module 340. If the system includes a catalytic hydrogenation module 360, the gas stream from the industrial, reactor and/or synthesis gas source 310 is supplied at conduit 312 to hydrolysis module 320 for converting at least one component in the gas stream to produce a post-hydrolysis gas stream. The hydrolysis gas stream passes through conduit 322 to an acid gas removal module 330. The acid gas removal module 330 removes at least one component 334 from the hydrolysis stream to produce a low acid gas content stream. The low acid gas stream passes through conduit 332 to catalytic hydrogenation module 360. Catalytic hydrogenation module 360 removes at least one component 364 from the low acid gas stream. The low acid gas stream is supplied from the catalytic hydrogenation module 360 to the deoxygenation module 340 via line 362. The deoxygenation module removes 340 at least one component 344 from the gas stream to produce a post-hydrogenation gas stream. At least a portion of the gas stream after hydrogenation can be supplied through line 342 to bioreactor 350 for fermentation. Preferably, the bioreactor contains N-fixing microorganisms capable of producing products 354 and a gaseous substrate from the gas stream after fermentation.

In specific embodiments of the invention, the hydrolysis module 320, the catalytic hydrogenation module 360, or both may be bypassed. By bypassing the hydrolysis module 320 and the catalytic hydrogenation module 360, the gas stream from the industrial, generator and/or synthesis gas source 310 is supplied through conduit 312 to the acid gas removal module 330. The acid gas removal module 330 removes at least one component 334 from a gas stream to produce a low acid gas stream. The low acid gas stream passes through conduit 332 to a deoxygenation module 340. The deoxygenation module 340 removes at least one component 344 from the low acid gas stream to produce a deoxygenation gas stream. At least a portion of the gas stream after deoxygenation can be supplied through line 342 to bioreactor 350 for fermentation. In specific embodiments of the invention, the catalytic hydrogenation module 360 is bypassed while the hydrolysis module 320 is used. In certain cases, the catalytic hydrogenation module 360 is used while the hydrolysis module 320 is bypassed.

At least a portion of the gaseous substrate after fermentation can be returned to one or more purification modules. In certain cases, the post-fermentation substrate gas is supplied through conduit 352 to a hydrolysis module 320 to convert one or more components in the post-fermentation substrate gas. In embodiments of the invention that bypass the hydrolysis module 320, the post-fermentation substrate gas may be supplied via conduit 352 to the acid gas removal module 330 to remove at least one component 334 from the post-fermentation substrate gas. In some cases, the gaseous substrate after fermentation can be stored in a carbon capture device.

The system may have additional modules selected from the group consisting of: solids removal module, chloride removal module, resin removal module, cyanide removal module

- 15 043304 hydrogen, additional acid gas removal module, temperature module and pressure module. These modules may be necessary to condition the gas flow between modules and/or effectively reduce component levels to acceptable levels.

In fig. 4 shows a system for selectively filtering components from a gas stream, including additional modules in the system. In specific embodiments of the invention, one or more modules may be installed after the deoxygenation module 440. If the system includes one or more modules after the deoxygenation module 440, the gas stream is supplied from the industrial, reactor and/or synthesis gas source 410 through conduit 412 to a hydrolysis module 420 for converting at least one component in the gas stream to produce a gas stream after hydrolysis. The hydrolysis gas stream is supplied through conduit 422 to an acid gas removal module 430. The acid gas removal module 430 removes at least one component 434 from the hydrolysis gas stream to produce a low acid gas content stream. The low acid gas stream is supplied through line 432 to catalytic hydrogenation module 460 to remove at least one component 464 from the gas stream. The gas stream is then passed through conduit 462 from the catalytic hydrogenation module 460 to the deoxygenation module 440. The deoxygenation module 440 removes at least one component 444 from the gas stream. The gas stream is supplied through conduit 442 from the deoxygenation module 440 to one or more additional modules 470. The one or more additional modules 470 remove and/or convert at least one component 474 in the gas stream. At least a portion of the gas stream from one or more additional modules 470 can be supplied through conduit 472 to the bioreactor 450 for fermentation. Preferably, the bioreactor contains III-fixing microorganisms capable of producing products 454 and a gaseous substrate from the gas stream after fermentation. In specific embodiments of the invention, one or more additional modules 470 are a hydrogen cyanide removal module and/or an additional acid gas removal module.

In specific embodiments, one or more additional modules 480 may be installed upstream of the hydrolysis module 420. If the system includes one or more modules upstream of the hydrolysis module 420, the gas stream is supplied from the industrial, reactor and/or synthesis gas source 410 through a pipeline 412 into one or more additional modules 480. The one or more additional modules 480 remove and/or convert at least one component 484 in the gas stream. The gas stream is then passed through line 482 to hydrolysis module 420 for further processing. In embodiments of the invention that bypass the hydrolysis module 420, the gas stream can be supplied through conduit 482 to the acid gas removal module 430. In particular embodiments of the invention, the system may include one or more additional modules 480 upstream of the hydrolysis module 420 and one or more additional 470 modules after 440 deoxygenation module.

At least a portion of the gaseous substrate after fermentation can be returned to one or more purification modules. In some cases, the post-fermentation substrate gas is supplied via conduit 452 to a hydrolysis module 420 to convert one or more components in the post-fermentation substrate gas. In embodiments of the invention that bypass the hydrolysis module 420, the post-fermentation substrate gas may be supplied via conduit 452 to the acid gas removal module 430 to remove at least one component 434 from the post-fermentation substrate gas. In embodiments of the invention that include one or more modules upstream of the hydrolysis module 420, the post-fermentation substrate gas may be supplied through conduit 452 to one or more additional modules 480. In some cases, the post-fermentation substrate gas may be stored in a carbon capture device.

Preferably, the gas stream is capable of being fermented by one or more C1-fixing microorganisms. The III-fixing microorganism in the bioreactor is usually a carboxydotrophic bacterium. In specific embodiments, the carboxydotrophic bacteria are selected from the group consisting of Moorella, Clostridium, Ruminococcus, Acetobacterium, Eubacterium, Butyribacterium, Oxobacter, Methanosarcina, Methanosarcina, and Desulfotomaculum. In various embodiments of the invention, the carboxydotrophic bacteria are Clostridium autoethanogenum.

The following examples are set forth as representative of the present invention. These examples should not be construed as limiting the scope of the invention, since these and other equivalent embodiments of the invention will be obvious in view of the present disclosure and the accompanying claims.

Example 1.

The gas purification system was configured to receive a mixed gas stream. The mixed gas stream is intended to represent the stream obtained from a steel mill. The gas purification system includes the following modules in the following order: (i) hydrolysis module, (ii) acid gas removal module, (iii) catalytic hydrogenation module and (iv) deoxygenation module. The hydrolysis module contains a layer of gamma alumina adsorbent (BASF F-200). Acid removal module

- 16 043304 gas contains a layer of zinc oxide adsorbent (RCI ZOP-116). The catalytic hydrogenation module contains palladium on alumina (BASF R0-20/47). The deoxygenation module contains a copper catalyst (BASF CU0226S).

Before testing the substrate, the hydrogenation catalyst was reduced in 1% _H2 in _N2 at 120°C for at least 12 hours. The deoxygenation catalyst was reduced in 1% _H2 in N2 at 250°C for at least 12 hours.

The composition of the mixed gas stream supplied to the gas purification system is illustrated in the table below.

Compound Hydrogen 6.8% Carbon monoxide 30.6% Carbon dioxide 18.4% Nitrogen 43.0% Water 4500 ppm Oxygen 6700 ppm Acetylene 500 ppm Hydrogen cyanide 60 ppm

In addition to the above compounds, trace amounts of methane and dimethyl ether were detected in the mixed stream. These compounds are impurities in the supplied gas.

The rates at which the gas flow was supplied and the inlet temperature of each module are illustrated in the table below. The pressure of each layer was 345 kPa (g).

Module Gas hourly volumetric velocity (GHSV), hour' ¹ Temperature at the module inlet, °C Guide roll from 2000 200 Acid gas removal 370 20 Catalytic hydrogenation 5500 120 Deoxygenation 4000 200

In this configuration, a fermentable gas stream was successfully obtained. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below.

Compound Oxygen 0.50 ppm Acetylene 0.062 ppm Hydrogen cyanide <0.010 ppm

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane found in the influent stream, thus no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are acetylene removal products and are not microbial inhibitors. No other contaminants were detected in the effluent stream using this configuration. No microbial inhibitors were formed using this configuration.

The CO concentration at the outlet was 30.1%. This output concentration corresponds to a consumption of 2.6% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

Example 2.

A gas purification system similar to Example 1 was configured to receive a mixed gas stream. The mixed gas stream is intended to represent the stream obtained from a steel mill. The gas purification system includes the following modules in the following order: (i) hydrolysis module, (ii) acid gas removal module and (iii) deoxygenation module. The hydrolysis module contains a layer of gamma alumina adsorbent (BASF F-200). The acid gas removal module contains a layer of zinc oxide adsorbent (RCI ZOP-116). The deoxygenation module contains a copper catalyst (BASF CU0226S).

The composition of the mixed gas stream supplied to the gas purification system is illustrated in the table below.

Compound Hydrogen 6.8% Carbon monoxide 30.6% Carbon dioxide 18.4% Nitrogen 43.0% Water 4500 ppm Oxygen 6700 ppm Acetylene 500 ppm Hydrogen cyanide 60 ppm

In addition to the above compounds, trace amounts of methane were detected in the mixed stream. These compounds are impurities in the supplied gas.

The gas flow rates and inlet temperatures of each module are illustrated in the table below. The pressure of each layer was 345 kPa (g).

Module Gas hourly volumetric velocity (GHSV), hour' ¹ Temperature at the module inlet, °C Hydrolysis 2000 200 Acid gas removal 370 20 Deoxygenation 4000 200

In this configuration, a fermentable gas stream was successfully obtained. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below. ______________________________________________

Compound Oxygen 0.45 ppm Acetylene 0.065 ppm Hydrogen cyanide <0.010 ppm

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane found in the influent stream, thus no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are products of acetylene removal. Trace amounts of dimethyl ether and acetaldehyde were detected. Dimethyl ether and acetaldehyde are not inhibitors of microorganisms. No microbial inhibitors were formed using this configuration.

Trace amounts of dimethyl ether and acetaldehyde were removed by passing the fermentation gas stream through an organic removal module. The gas flow rate into the organic compound removal module was such that the hourly space velocity of the gas was 370 h' ¹ .

The output CO concentration was 29.8%. This output concentration corresponds to a consumption of 4.0% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

In addition to operating the gas purification system at 345 kPa(g), using this configuration and this gas composition, the inventors increased the pressure so that the pressure of each layer was 690 kPa(g) to evaluate how the pressure might affect the system.

It was found that at elevated pressure (690 kPa(g) for each layer), a fermentable gas stream was successfully produced in this configuration. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below.

- 18043304

Compound Oxygen 0.41 ppm Acetylene 0.076 ppm Hydrogen cyanide <0.010 ppm

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane found in the influent stream, thus no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are acetylene removal products and are not microbial inhibitors. Trace amounts of dimethyl ether and acetaldehyde were detected. Dimethyl ether and acetaldehyde are not inhibitors of microorganisms. Using this configuration, no impurities were detected in the effluent.

Trace amounts of dimethyl ether and acetaldehyde were removed by passing the fermentation gas stream through an organic removal module. The gas flow rate into the organic compound removal module was such that the hourly gas space velocity was 370 h ^-1 .

The output CO concentration was 29.8%. This output concentration corresponds to a consumption of 3.3% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

Example 3.

The gas purification system was configured to receive a mixed gas stream. The mixed gas stream is intended to represent the stream obtained from a steel mill. The gas purification system includes the following modules in the following order: (i) hydrolysis module, (ii) acid gas removal module, (iii) catalytic hydrogenation module, (iv) deoxygenation module and (v) organic removal module. The hydrolysis module contains a layer of gamma alumina adsorbent (BASF F-200). The acid gas removal module contains a layer of zinc oxide adsorbent (RCI ZOP-116). The catalytic hydrogenation module contains palladium on alumina (BASF R020/47). The deoxygenation module contains a copper catalyst (BASF Cu0226S).

Before testing the substrate, the hydrogenation catalyst was reduced in 1% H2 in N2 at 120°C for at least 12 hours. The deoxygenation catalyst was reduced to 1% _H2 in N2 at 250°C for at least 12 hours

The composition of the mixed gas stream supplied to the gas purification system is illustrated in the table below.

Compound Hydrogen 6.2% Carbon monoxide 27.6% Carbon dioxide 16.2% Nitrogen 49.1% Water 2400 ppm Hydrogen sulfide 40.0 ppm Carbonyl sulfide 4.0 ppm Oxygen 6000 ppm Acetylene 550 ppm Hydrogen cyanide 20 ppm

In addition to the above compounds, trace amounts of methane were detected in the mixed stream. These compounds are impurities in the supplied gas.

The gas flow rates and inlet temperatures of each module are illustrated in the table below. The pressure of each layer was 690 kPa(g).

- 19 043304

Module Gas hourly volumetric velocity (GHSV), hour' ¹ Temperature at the module inlet, °C Hydrolysis 2000 200 Acid gas removal 370 20 Catalytic hydrogenation 5500 120 Deoxygenation 4000 200 Removal of organic compounds 370 20

In this configuration, a fermentable gas stream was successfully obtained. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below.

Compound Oxygen 0.38 ppm Acetylene 0.168 ppm Hydrogen cyanide <0.030 ppm

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane detected as an impurity in the influent stream, so no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are acetylene removal products and are not microbial inhibitors. No other contaminants were detected in the effluent stream using this configuration. No microbial inhibitors were generated using this module configuration.

The output CO concentration was 26.6%. This output concentration corresponds to a consumption of 3.8% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

Example 4.

The gas purification system was configured similarly to Example 3 to produce a mixed gas stream. The mixed gas stream is intended to represent the stream obtained from a steel mill. The gas purification system includes the following modules in the following order: (i) hydrolysis module, (ii) acid gas removal module, (iii) deoxygenation module and (iv) organic removal module. The hydrolysis module contains a layer of gamma alumina adsorbent (BASF F-200). The acid gas removal module contains a layer of zinc oxide adsorbent (RCI ZOP-116). The deoxygenation module contains a copper catalyst (BASF Cu0226S).

The composition of the mixed gas stream supplied to the gas purification system is illustrated in the table below.

In addition to the above compounds, trace amounts of methane were detected in the mixed stream. These compounds are impurities in the supplied gas.

- 20 043304

The gas flow rates and inlet temperatures of each module are illustrated in the table below. The pressure of each layer was 690 kPa(g).

Module Gas hourly volumetric velocity (GHSV), hour' ¹ Temperature at the module inlet, °C Guide role 2000 200 Acid gas removal 370 20 Deoxygenation 4000 200 Removal of organic compounds 370 20

In this configuration, a fermentable gas stream was successfully obtained. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below.

Compound Oxygen 0.34 ppm Acetylene 0.073 ppm Hydrogen cyanide <0.010 ppm

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane detected as an impurity in the influent stream, so no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are acetylene removal products and are not microbial inhibitors. No other contaminants were detected in the effluent stream using this configuration. No microbial inhibitors were produced when using this module configuration.

The output CO concentration was 26.2%. This output concentration corresponds to a consumption of 4.9% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

Example 5.

A gas purification system similar to Example 2 was configured to receive a mixed gas stream. The mixed gas stream has higher concentrations of microbial inhibitors. Concentrations are in the range expected from gasification of biomass or municipal solid waste or purified coke oven gas. The gas purification system includes the following modules in the following order: (i) hydrolysis module, (ii) acid gas removal module, (iii) deoxygenation module and (iv) organic removal module. The hydrolysis module contains a layer of gamma alumina adsorbent (BASF F-200). The acid gas removal module contains a layer of zinc oxide adsorbent (RCI ZOP-116). The deoxygenation module contains a copper catalyst (BASF Cu0226S).

Before substrate testing, the deoxygenation catalyst was reduced in 1% _H2 in N2 at 250°C for at least 12 h.

The composition of the mixed gas stream supplied to the gas purification system is illustrated in the table below. _____________________________________________________

Compound Hydrogen 4.1% Carbon monoxide 17.8% Carbon dioxide 10.7% Nitrogen 66.3% Water 2000 ppm Oxygen 7600 ppm Acetylene 860 ppm Hydrogen cyanide 280 ppm

In addition to the above compounds, trace amounts of methane were detected in the mixed stream. This compound is an impurity in the supply gas.

- 21 043304

The rates at which the gas flow was supplied and the inlet temperature of each module are illustrated in the table below. The pressure of each layer was 690 kPa(g).

Module Gas hourly volumetric velocity (GHSV), hour' ¹ Temperature at the module inlet, °C Hydrolysis 2000 200 Acid gas removal 370 20 Deoxygenation 4000 200 Removal of organic compounds 370 20

In this configuration, a fermentable gas stream was successfully obtained. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below.

Compound Oxygen 0.46 ppm Acetylene 0.040 ppm Hydrogen cyanide <0.010 ppm

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane detected as an impurity in the influent stream, so no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are acetylene removal products and are not microbial inhibitors. No other contaminants were detected in the effluent stream using this configuration. No microbial inhibitors were produced when using this module configuration.

The output CO concentration was 16.6%. This output concentration corresponds to a consumption of 6.8% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

Example 6.

The gas purification system was configured to receive a mixed gas stream. The mixed gas stream is intended to represent the stream obtained from a steel mill. The gas purification system includes only one module. The module contained a copper catalyst (BASF Cu0226S).

Before substrate testing, the deoxygenation catalyst was reduced in 1% H2 to N2 at 250°C for at least 12 h.

The composition of the mixed gas stream supplied to the gas purification system is illustrated in the table below.

Compound Hydrogen 7.0% Carbon monoxide 31.6% Carbon dioxide 18.5% Nitrogen 41.9% Water 4500 ppm Oxygen 5900 ppm Acetylene 490 ppm Hydrogen cyanide 20 ppm

In addition to the above compounds, trace amounts of methane were detected in the mixed stream. This compound is an impurity in the supply gas.

The gas flow rate corresponds to the hourly gas volumetric velocity of 4000 h ^-1 . The temperature at the module inlet was 200°C. The pressure in the module was 690 kPa(g).

A fermentable gas stream was successfully produced in this module. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below.

- 22 043304

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane detected as an impurity in the influent stream, so no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are acetylene removal products and are not microbial inhibitors. Methanol was detected in the fermentation gas stream. Methanol is not an inhibitor of microorganisms. No other contaminants were detected in the effluent stream using this configuration. No microbial inhibitors were formed using this module configuration.

The output CO concentration was 30.2%. This output concentration corresponds to a consumption of 4.2% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

Example 7.

The gas purification system was configured to receive a mixed gas stream. The mixed gas stream is intended to represent the stream obtained from a steel mill. The gas purification system includes only one module. The module contained a copper catalyst (BASF Cu0226S).

Before substrate testing, the catalyst was reduced in 1% H2 in N2 at 250°C for at least 12 hours. After reduction, the catalyst was sulfided using a gas stream containing 1% H2S, 5% H2 in N2. The catalyst was sulfided at 220°C for 18 hours.

The composition of the mixed gas stream supplied to the gas purification system is illustrated in the table below.

Compound Hydrogen Carbon monoxide Carbon dioxide Nitrogen Water Hydrogen sulfide 6.1% 27.2% 16.0% 49.8% 2400 ppm 39 ppm Carbonyl sulfide 4.0 ppm Oxygen 6200 ppm Acetylene 550 ppm Hydrogen cyanide 19 ppm

In addition to the above compounds, trace amounts of methane were detected in the mixed stream. This compound is an impurity in the supply gas.

The gas flow rate corresponds to the hourly gas volumetric velocity of 2000 h ^-1 . The temperature at the module inlet was 280°C. The pressure in the module was 690 kPa(g).

A fermentable gas stream was successfully produced in this module. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below.

Compound Oxygen 0.42 ppm Acetylene 0.581 ppm Hydrogen cyanide 0.011 ppm

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane detected as an impurity in the influent stream, so no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are acetylene removal products and are not microbial inhibitors. Acetaldehyde was detected in the fermentation gas stream. Acetaldehyde is not

- 23 043304 is an inhibitor of microorganisms. No other contaminants were detected in the effluent stream using this configuration. No microbial inhibitors were generated using this module configuration.

The output CO concentration was 26.9%. This output concentration corresponds to a consumption of 1.0% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

Example 8.

A gas purification system similar to Example 7 was configured to receive a mixed gas stream. The mixed gas stream contained higher concentrations of microbial inhibitors. Concentrations are in the range expected from gasification of biomass or municipal solid waste or purified coke oven gas. The gas purification system includes only one module. The module contained a copper catalyst (BASF Cu0226S).

The composition of the mixed gas stream supplied to the gas purification system is illustrated in the table below.

Compound Hydrogen 3.8% Carbon monoxide 16.4% Carbon dioxide 9.1% Nitrogen 69.6% Water 2200 ppm Hydrogen sulfide 40 ppm Carbonyl sulfide 4 ppm Oxygen 6600 ppm Acetylene 1060 ppm Hydrogen cyanide 400 ppm

In addition to the above compounds, trace amounts of methane were detected in the mixed stream. This compound is an impurity in the supply gas.

The gas flow rate corresponds to the hourly gas volumetric velocity of 1000 h ^-1 . The temperature at the module inlet was 300°C. The pressure in the module was 690 kPa(g).

A fermentable gas stream was successfully produced in this module. The target for removing contaminants has been achieved. The composition of the fermentation gas stream is illustrated in the table below.

Compound Oxygen 3.1 ppm Acetylene 0.960 ppm Hydrogen cyanide 0.280 ppm

Trace amounts of methane were detected in the fermentation gas stream. However, the amount of methane in the effluent stream was similar to the amount of methane detected as an impurity in the influent stream, so no methane formation was detected. Traces of ethane and ethylene were found. Ethane and ethylene are acetylene removal products and are not microbial inhibitors. Acetaldehyde was detected in the fermentation gas stream. Acetaldehyde is not an inhibitor of microorganisms. No other contaminants were detected in the effluent stream using this configuration. No microbial inhibitors were generated using this module configuration.

The output CO concentration was 15.9%. This output concentration corresponds to a consumption of 3.0% of incoming CO, which is significantly lower than the preferred maximum consumption of 10%.

All references, including publications, patent applications and patents cited herein, are incorporated herein by reference to the same extent as if each reference had been separately and specifically indicated for inclusion by reference and set forth herein in its entirety. volume. In this specification, reference to any prior art does not constitute, and should not be construed as, an admission that such prior art is part of the public knowledge of the art in any country.

The use of the singular terms and similar references in the context of the description of the present invention (especially in the context of the following claims) should be considered to include:

Claims (4)

is both singular and plural, unless otherwise stated herein or clearly inconsistent with the context. The terms containing, having, including, and encompassing are to be considered non-limiting terms (i.e., including, but not limited to), unless otherwise noted. The term essentially consisting of limits the scope of the composition, process or method to specified materials or steps, or that does not significantly affect the essential and novel characteristics of the composition, process or method. The use of an alternative (i.e. or) should be understood to mean one, both, or any combination of the options offered. As used herein, the term about means ±20% of the stated range, value, or structure unless otherwise noted. The listing of ranges of values in this document is simply intended to serve as a shorthand way of individually referring to each individual value falling within that range, unless otherwise noted herein, with each individual value included in the description as if it were separately listed in this document. For example, any concentration range, percentage range, ratio range, whole number range, size range, or thickness range should be understood to include the value of any whole number within the specified range and, if appropriate, fractions thereof (for example, one tenth and one hundredth of a whole number ), unless otherwise specified. All methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly inconsistent with the context. The use of any and all examples or illustrative language (i.e., such as) presented herein is intended only to better illuminate the present invention and is not intended to limit the scope of the present invention unless otherwise stated. Nothing contained in this specification should be construed as indicating any unclaimed element as being necessary for the practice of this invention. This document describes preferred embodiments of the present invention. Variations of these preferred embodiments of the invention will become apparent to those skilled in the art upon reading the above description. The inventors expect that those skilled in the art will use such variations when necessary, and the inventors expect that the present invention will be practiced differently than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter of the invention given in the accompanying claims, as established by applicable law. Moreover, any combination of the elements described above, in all possible variations thereof, is encompassed by this invention unless otherwise indicated herein or otherwise clearly contrary to the context. CLAIM 1. A method for producing a fermentable gas stream from an incoming gas stream, wherein the incoming gas stream contains CO, CO ₂ or H ₂ or a combination thereof, comprising the following steps: a) passing the incoming gas stream through a hydrolysis module in which at least one component of the gas stream is removed and/or converted to produce a hydrolysis gas stream; b) passing the gas stream obtained after hydrolysis through an acid gas removal module, in which at least one additional component of the gas stream is removed and/or converted to obtain a gas stream with a low acid gas content; c) passing the low acid gas stream, before being sent to the deoxygenation module, through a catalytic hydrogenation module, where at least one component of the low acid gas gas stream is removed and/or converted before being sent to the deoxygenation module; d) passing the low acid gas content gas stream through a deoxygenation module in which at least one additional component is removed and/or converted to produce a fermentable gas stream; And e) passing at least a portion of the fermentation gas stream through a bioreactor, where the bioreactor contains a culture including a fermentation broth and one or more microorganisms. 2. The method according to claim 1, characterized in that at least one removed and/or converted component is a microbial inhibitor and/or a catalyst inhibitor. 3. The method according to claim 1, characterized in that at least one or more components removed and/or converted by the hydrolysis module are carbonyl sulfide (COS) and/or hydrogen cyanide (HCN). 4. The method according to claim 1, characterized in that at least one or more components removed and/or converted by the acid gas removal module are selected from the group consisting of carbon dioxide (CO ₂ ), hydrogen sulfide (H ₂ S) and hydrogen cyanide (HCN). -