Process for methanol production

Abstract

The invention relates to a process for methanol production, wherein the process comprises the steps of: a) supplying one or more gaseous input streams to a plasma reactor, wherein the one or more gaseous input streams comprise at least CO2 and CH4; b) igniting a plasma in the plasma reactor, thereby dry reforming the CH4 to form a synthesis gas comprising CO and H2; c) supplying the synthesis gas to a methanol reactor, wherein the CO and H2 in the synthesis gas are at least partially converted to a liquid phase comprising at least methanol, wherein the plasma reactor and the methanol reactor are fluidly connected, and the gaseous input streams comprise a volume ratio of the total amount of CH4 to the total amount of CO2 of at least 2.

Description

Technical Field

[0001] This invention relates to a method for optimizing syngas for methanol production. Background Technology

[0002] Methanol, also known as methyl alcohol (CH3OH or MeOH), is a widely used bulk chemical with diverse applications across various industries. Its light weight and flammability make it suitable for a range of applications, from industrial processes to serving as an alternative fuel for internal combustion engines.

[0003] In recent years, the rising levels of greenhouse gases such as carbon dioxide (CO2) and hydrogen carriers (methane) have become a major environmental problem. Growing awareness of climate change and the potential release of hydrogen carriers from frozen deposits in the Arctic highlights the need for innovative solutions to mitigate the environmental impacts of these potent greenhouse gases. Notably, methane is approximately ten times more potent as a greenhouse gas than carbon dioxide.

[0004] Traditional approaches to addressing greenhouse gas emissions typically involve separate capture and conversion processes, leading to increased complexity, energy consumption, and costs. Therefore, there is a need for an integrated and efficient system capable of simultaneously capturing, separating, and converting a mixture of CO2 and hydrogen carriers into a valuable and environmentally friendly end product.

[0005] The present invention aims to solve at least one of the above-mentioned disadvantages. Summary of the Invention

[0006] The present invention and its embodiments are intended to provide solutions to one or more of the aforementioned disadvantages. Therefore, the present invention relates to the method according to claim 1. Preferred embodiments of the method are shown in any one of claims 2 to 11.

[0007] In a second aspect, the present invention relates to the system according to claim 12. Preferred embodiments of the system are shown in any one of claims 11 to 15.

[0008] In this system, a direct fluid connection is established between the plasma reactor outlet and the methanol reactor inlet, providing significant benefits for the conversion of greenhouse gases into methanol. This configuration ensures that the synthesis gas (syngas) from the plasma reactor (a mixture of CO2 and hydrogen carrier converted to H2 and CO) flows seamlessly and continuously directly into the methanol reactor for immediate conversion into methanol. This direct connection minimizes the exposure of the synthesis gas to atmospheric pollutants and reduces the risk of gas composition changes that may occur between stages due to cooling or interaction with the external environment. It improves the efficiency of the entire process by maintaining suitable temperature and pressure conditions favorable to the chemical reactions involved, thereby increasing the yield and purity of the produced methanol. Furthermore, it simplifies system design, reducing the need for additional piping, valves, and intermediate storage, which in turn reduces capital and operating costs. Integrating these reactors into a streamlined process fully utilizes the high reactivity and energy efficiency of plasma-assisted conversion, resulting in a more compact, efficient, and environmentally friendly methanol production system.

[0009] In a third aspect, the present invention relates to the use as described in claim 15. Detailed Implementation

[0010] Unless otherwise defined, all terms used in disclosing this invention (including technical and scientific terms) have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains. Definitions of terms are incorporated to provide further guidance and to better understand the teachings of this invention.

[0011] As used herein, the following terms have the following meanings: As used herein, “a,” “an,” and “the / said” refer to both singular and plural entities, unless the context clearly indicates otherwise. For example, “a compartment” refers to one or more compartments.

[0012] As used herein, the term "about" refers to measurable values ​​(e.g., parameters, quantities, durations of time, etc.) and is intended to cover variations of up to + / -20%, preferably up to + / -10%, more preferably up to + / -5%, even more preferably up to + / -1%, and still more preferably up to + / -0.1%, provided that such variations are suitable for carrying out the disclosed invention. However, it should be understood that the value modified by "about" is itself specifically disclosed.

[0013] As used herein, “comprise”, “comprising”, “comprises” and “comprised of” are synonymous with “include”, “including”, “includes” or “contain”, and are inclusive or open-ended terms that indicate the presence of the following content (e.g., components) but do not exclude or preclude the presence of other parts, features, elements, members or steps known in the art or disclosed herein that are not mentioned.

[0014] Furthermore, the terms first, second, third, etc., in the specification and claims are used to distinguish similar elements and are not necessarily used to describe order or chronological sequence, unless otherwise stated. It should be understood that such terms are interchangeable where appropriate, and the embodiments of the invention described herein can operate in a sequence different from that described or shown herein.

[0015] The range of values ​​expressed in terms of endpoints includes all numbers and fractions contained within that range, as well as the endpoints themselves.

[0016] Unless otherwise defined, the expressions “% by weight,” “percentage by weight,” “%wt” or “wt%” used throughout the instructions refer to the relative weight of each component with respect to the total weight of the formulation.

[0017] The meaning of the terms “one or more” or “at least one” (e.g., one or more or at least one member of a group of members) is clear in itself; as a further example, the term specifically includes referring to any one of the members, or referring to any two or more of the members, such as any ≥3, ≥4, ≥5, ≥6 or ≥7 of the members, or even all of the members.

[0018] Unless otherwise defined, all terms used in disclosing this invention (including technical and scientific terms) have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains. Definitions of terms used in this specification are incorporated to provide further guidance and to better understand the teachings of this invention. The terms or definitions used herein are for illustrative purposes only.

[0019] Throughout this specification, the terms "one embodiment" or "an embodiment" refer to a specific feature, structure, or characteristic described in connection with that embodiment being included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment, but may refer to the same one. Furthermore, as will be apparent to those skilled in the art from this disclosure, specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Moreover, while some embodiments described herein include features not included in other embodiments, combinations of features from different embodiments are intended to fall within the scope of the invention and form different embodiments, as understood by those skilled in the art. For example, in the appended claims, any claimed embodiments can be used in any combination.

[0020] In a first aspect, the present invention relates to a method for hydrocarbon production, preferably methanol production.

[0021] The method includes the following steps: a. Supplying one or more gaseous input streams to the plasma reactor, wherein the one or more gaseous input streams contain at least a CO2 and a hydrogen source; and b. Ignite the plasma in the plasma reactor, thereby causing the CO2 and the hydrogen source to react and form a synthesis gas containing CO and H2.

[0022] In the plasma reactor, plasma is ignited, causing CO2 and a hydrogen source to react and form syngas. The conversion of CO2 and hydrogen in the plasma reactor produces syngas containing CO and H2 according to reaction (A).

[0023] (A)

[0024] As used in this article, the term "hydrogen source" refers to any molecule that, under specific conditions (in this case, a plasma reactor), can release hydrogen atoms to participate in chemical reactions, particularly for the production of syngas from CO2.

[0025] In a preferred embodiment, the hydrogen source is a hydrocarbon selected from the following list: methane, ethane, propane, butane, etc., preferably methane (CH4). If the hydrogen source is methane, then methane dry reforming (B) is performed in a plasma reactor.

[0026] In a particularly preferred embodiment, the method includes the following steps: a. Supplying one or more gaseous input streams to the plasma reactor, wherein the one or more gaseous input streams contain at least CO2 and CH4; and b. Ignite the plasma in the plasma reactor to dry reform the CH4 and form a synthesis gas containing CO and H2.

[0027] The syngas obtained by this method has been proven to be highly suitable for hydrocarbon production, preferably methanol production. Therefore, in another preferred embodiment, the method includes step c): supplying the syngas to a Fischer-Tropsch reactor, preferably a methanol reactor.

[0028] In a particularly preferred embodiment, the method includes the following steps: a. Supplying one or more gaseous input streams to the plasma reactor, wherein the one or more gaseous input streams contain at least CO2 and a hydrogen source, preferably CH4; b. Ignite the plasma in the plasma reactor, thereby causing the CO2 and hydrogen source (preferably CH4) to react and form a synthesis gas containing CO and H2; c. The syngas is supplied to a Fischer-Tropsch reactor, preferably a methanol reactor.

[0029] In the plasma reactor, plasma is ignited, causing CO2 and CH4 to react and form syngas. The conversion of CO2 and CH4 in the plasma reactor (dry reforming of methane) produces syngas containing CO and H2 according to reaction (B).

[0030] (B)

[0031] When the resulting syngas is preferably used to produce methanol according to reaction (C), the optimal molar ratio of CO to H2 in the syngas is 1:2.

[0032] (C)

[0033] Reaction (C) shows that a molar ratio of 1:2 for CO and H2 is the optimal mixture for methanol synthesis.

[0034] The inventors have discovered that the volume ratio of the total amount of CH4 to the total amount of CO2 contained in the one or more gaseous input streams is advantageously at least 2.

[0035] Controlling the input hydrogen source fraction provides highly sensitive, coarse control.

[0036] This specific ratio is important because it optimizes syngas formation, thereby facilitating subsequent methanol production. In this case, the syngas is a favorable mixture for methanol synthesis due to the H2 to CO volume ratio being close to 2 and the absence of soot generation (ideal conditions for methanol production). Therefore, the method provides an innovative approach to methanol production that utilizes a plasma reactor and a specific gas input ratio to optimize the process.

[0037] This system facilitates the direct and immediate conversion of the main inputs (i.e., CO2 and CH4) into syngas. This eliminates the need for any preparatory steps or temporary storage, improves process efficiency, and ensures continuous flow throughout the process. Its performance advantages have been observed to exceed those achieved by operating at stoichiometric ratios, making it an enhanced, flexible, and environmentally friendly alternative to traditional gas reforming methods.

[0038] In a preferred embodiment, the one or more gaseous input streams contain a total amount of at least 20% by volume, preferably at least 30% by volume, more preferably at least 40% by volume, even more preferably at least 50% by volume, even more preferably at least 60% by volume, even more preferably at least 65% by volume of CH4.

[0039] In a preferred embodiment, the one or more gaseous input streams contain a total amount of CH4 ranging from 20% to 80% by volume, preferably 30% to 80% by volume, more preferably 40% to 80% by volume, even more preferably 50% to 80% by volume, even more preferably 60% to 80% by volume, even more preferably 65% ​​to 80% by volume.

[0040] In a preferred embodiment, the one or more gaseous input streams contain a total amount of CO2 of up to 60% by volume, preferably up to 50% by volume, more preferably up to 40% by volume, and even more preferably up to 35% by volume.

[0041] In a preferred embodiment, the one or more gaseous input streams contain a total amount of 20% to 60% by volume, preferably 20% to 50% by volume, more preferably 20% to 40% by volume, even more preferably 20% to 35% by volume, and even more preferably 20% to 35% by volume of CO2.

[0042] In a preferred embodiment, the one or more gaseous input streams contain a total of up to 20% by volume, preferably up to 10% by volume, more preferably up to 5% by volume, even more preferably up to 2% by volume, even more preferably up to 1% by volume, even more preferably up to 0.5% by volume of water. Most preferably, the gaseous input streams are substantially free of water. In the case of dry methane reforming (DRM), controlling the water content in the gaseous input streams is particularly advantageous because excessive water can interfere with reaction kinetics, promote undesirable side reactions, and alter the desired H2 to CO ratio. Maintaining a low water content ensures efficient DRM reaction, improves syngas quality, and optimizes downstream methanol or other hydrocarbon production. Furthermore, a lower water content reduces the risk of catalyst deactivation and minimizes the need for additional separation steps, thereby improving overall process efficiency.

[0043] In an alternative embodiment, the one or more gaseous input streams may contain a controlled amount of water, preferably at least 0.01% by volume, more preferably at least 0.05% by volume, even more preferably at least 0.1% by volume, even more preferably at least 1% by volume, and most preferably from 0.1% to 10% by volume. The presence of a controlled amount of water in the gaseous input stream can help mitigate the formation of solid carbon (soot), a known challenge in dry methane reforming. Water in the input stream promotes the oxidation pathway, helping to suppress carbon deposition on the reactor surface and within the plasma zone, preventing catalyst deactivation and reactor fouling. Even trace amounts of solid carbon can have a disproportionately negative impact on plasma stability, as carbon particles can accumulate within the plasma reactor, altering the conductivity of the discharge and causing localized disturbances in the plasma field. This instability reduces conversion efficiency, increases energy consumption, and ultimately requires more frequent reactor maintenance.

[0044] In a preferred embodiment, the one or more gaseous input streams contain a total amount of water of at most 1% by volume, preferably at most 0.5% by volume, more preferably at most 0.1% by volume, even more preferably at most 1000 ppm, even more preferably at most 500 ppm, and most preferably at most 100 ppm. In the case of direct plasma methane reforming (including dry methane reforming (DRM)), keeping the water content in the gaseous input streams extremely low is particularly advantageous, as even trace amounts of water can significantly affect the reaction pathway.

[0045] Increased water content leads to a higher concentration of OH radicals in the plasma, which promotes H2O formation while inhibiting H2 generation, and also promotes OH radical recombination with CO, thereby reducing CO yield. Therefore, increased OH radical concentration directly reduces syngas production efficiency and decreases the yields of both H2 and CO during plasma-driven reforming. While these effects can be mitigated by using catalysts that selectively drive the desired reaction pathways, the catalytic system presents additional challenges, including coking, sintering, and deactivation over time. By ensuring an ultra-low water content in the gaseous input stream, the method of this invention advantageously maximizes syngas yield, maintains long-term reactor stability, and reduces the need for complex catalyst regeneration or additional purification steps.

[0046] Clearly, there is a trade-off between adding water to the gaseous input stream in direct plasma methane reforming (DRM). On the one hand, water plays a beneficial role in suppressing solid carbon formation, thereby mitigating problems such as plasma instability, reactor fouling, and electrode degradation. Furthermore, the presence of water increases the H2 / CO ratio, which can be advantageous for downstream applications such as methanol synthesis, where higher hydrogen content is typically preferred. However, these benefits come at a significant cost. Increased water content leads to a higher concentration of OH radicals in the plasma, promoting a combined pathway that reduces the yields of both H2 and CO. This shift in reaction pathways reduces overall syngas production efficiency because more energy is consumed in forming H2O rather than driving the necessary dissociation of CH4 and CO2. Therefore, while water can improve process stability and selectivity under certain conditions, excessive water can severely impair yield and energy efficiency. Achieving an optimal balance between these competing effects is crucial for optimizing direct plasma DRM, ensuring that the benefits of carbon suppression are realized without sacrificing overall process performance.

[0047] In an alternative embodiment, the one or more gaseous input streams may further contain oxygen, preferably at least 0.01% by volume, more preferably at least 0.1% by volume, even more preferably at least 1% by volume, more preferably at least 3% by volume, more preferably at least 5% by volume, more preferably at least 7% by volume, more preferably at least 10% by volume, and most preferably at least 0.1% by volume and 10.0% by volume. In another embodiment, the one or more gaseous input streams may further contain up to 30% by volume, preferably up to 20% by volume, more preferably up to 15% by volume, even more preferably up to 10% by volume, even more preferably up to 7% by volume, and most preferably up to 5% by volume of oxygen. This controlled addition of oxygen promotes oxy-reforming of methane, a process that integrates dry reforming (DRM) and partial oxidation (POM), improving syngas production efficiency while reducing carbon deposition. Oxy-reforming of methane involves the reaction of methane with both CO2 and O2 to form CO and H2 through complementary reaction pathways. The presence of oxygen promotes the partial oxidation of methane, which provides additional heat to sustain the endothermic dry reforming reaction, thereby improving overall energy efficiency. Furthermore, oxygen plays a crucial role in limiting solid carbon (soot) formation because it enables oxidation reactions to convert carbon deposits into CO and CO2, reducing reactor fouling and plasma instability. However, excessive oxygen can lead to the undesirable complete oxidation of methane, producing CO2 and H2O instead of the desired syngas components.

[0048] In a preferred embodiment, CO2 is captured by adsorption, cryogenic distillation, membrane, or chemical looping.

[0049] Utilizing CO2 captured from these sources (adsorption, cryogenic distillation, membrane, or chemical looping) in methanol production offers a dual synergy of environmental and economic benefits. This method uses the potent greenhouse gas CO2 as a feedstock, effectively transforming an environmental burden into a valuable input. By directly integrating CO2 capture and utilization into methanol production, this strategy not only reduces the carbon footprint of industrial and agricultural processes but also improves the overall efficiency and sustainability of methanol manufacturing. It aligns with circular economy principles by recycling carbon emissions into useful products, thereby mitigating the impacts of climate change while meeting the growing demand for methanol as a fuel and industrial chemical. This integration also opens pathways for industry to achieve carbon neutrality or carbon-negative emissions, as it value-added emissions that would otherwise exacerbate atmospheric CO2 levels, making it a valuable complement to existing methanol production methods.

[0050] In a preferred embodiment, the hydrogen source is selected from the following list: fossil fuels, biogas, syngas, or a mixture of gases obtained by hydrogenation of CO2.

[0051] Choosing hydrogen sources for methanol production from fossil fuels, biogas, syngas, or mixtures of gases derived from CO2 hydrogenation significantly improves the environmental profile of the process. By introducing renewable and low-carbon hydrogen sources such as biogas and syngas, this approach reduces dependence on fossil fuels and lowers greenhouse gas emissions. For example, biogas utilizes organic waste, converting it into a valuable resource, thus contributing to waste reduction and promoting sustainability. Syngas can be produced from renewable energy sources, further reducing the carbon footprint of the methanol production process. Furthermore, using mixtures of gases derived from CO2 hydrogenation not only uses CO2 as a feedstock, preventing its release into the atmosphere, but also promotes carbon recycling. This approach directly aligns with global environmental goals by providing a cleaner and more sustainable pathway to methanol production, highlighting the importance of reducing carbon emissions and efficiently utilizing resources in industrial processes.

[0052] In a particularly preferred embodiment, a gaseous input stream, wherein the gaseous input stream is biogas, is supplied to the plasma reactor. In this embodiment, methane and carbon dioxide are entirely present in the biogas and are supplied to the plasma reactor.

[0053] The biogas input stream is a renewable energy source, typically produced from raw materials such as biological waste, feces, municipal solid waste, sewage, and green waste. This biogas is generated through an anaerobic digestion process by microorganisms within a biochamber or bioreactor. The resulting gas composition is primarily a mixture of CH4, CO2, and trace amounts of H2O, H2S, and H2. In this preferred embodiment, the composition of the biogas used can vary, but it typically consists mainly of CH4, CO2, and trace amounts of H2O.

[0054] Typically, gas mixtures are purified through separation stages (such as distillation or pressure swing adsorption). This removes undesirable products such as CO2 and H2O. This approach increases costs because the separation process can be energy-intensive. Furthermore, CO2 gas is emitted, which is undesirable. While CO2 gas can be captured, this further increases the price of the CH4 product.

[0055] The inventors have now discovered a method to solve this problem by skipping the separation stage and replacing it with a specific plasma reactor that facilitates dry reforming.

[0056] Therefore, in this preferred embodiment, the method is characterized by supplying a single gaseous input stream, specifically biogas, in step a. This embodiment is particularly advantageous in terms of efficiency and resource optimization. The present invention allows for the direct use of biogas, thereby improving overall process efficiency. It eliminates the need for biogas purification steps, which typically require significant energy input and increase production costs. By eliminating these steps, the present invention not only saves energy but also reduces the overall cost of methanol production.

[0057] Furthermore, this invention converts waste biogas into valuable methanol, thereby achieving greater resource optimization. Biogas, typically composed of methane, carbon dioxide, and trace amounts of water, hydrogen sulfide, and hydrogen, is generally considered a waste product. However, using this invention, this waste product is converted into a valuable compound—methanol—which has numerous industrial applications. This not only increases the value of biogas but also helps reduce waste and promote a circular economy.

[0058] It should be understood that, in this particular embodiment, when a single gaseous input stream (specifically biogas) is supplied to the plasma reactor in step a, the above-described proportions and compositions of one or more gaseous input streams also apply. For example, "the volume ratio of the total amount of CH4 contained in the gaseous input stream to the total amount of CO2 is at least 2" is equivalent to "the volume ratio of the total amount of CH4 contained in the biogas to the total amount of CO2 is at least 2".

[0059] In a particularly preferred embodiment, the method includes the following steps: a. Supplying a gaseous input stream to the plasma reactor, wherein the gaseous input stream is biogas, and wherein the gaseous input stream contains at least CO2 and CH4; b. Ignite the plasma in the plasma reactor to dry reform the CH4 to form a syngas containing CO and H2; c. The syngas is supplied to a Fischer-Tropsch reactor, preferably a methanol reactor. The volume ratio of the total amount of CH4 to the total amount of CO2 contained in the biogas is at least 2.

[0060] In a preferred embodiment, the biogas is produced from food waste, sewage sludge, agricultural waste, animal manure, or aquatic biomass.

[0061] - Food waste: Food scraps and waste from households, restaurants, and the food processing industry typically have a high moisture content. After anaerobic digestion, the resulting biogas can contain a significant amount of water vapor.

[0062] - Sewage sludge: Anaerobic digestion of sewage sludge (the semi-solid material left after sewage treatment) can also produce biogas with high water content. This is because sewage sludge usually contains a high percentage of water.

[0063] - Agricultural waste: Certain types of agricultural waste (such as vegetable waste, green plant material, and fruit waste) have a high moisture content. When these materials undergo anaerobic digestion, the resulting biogas often has a high water vapor content.

[0064] - Animal manure: Manure from livestock such as cattle, pigs, and poultry contains a large amount of water. Anaerobic digestion of these materials not only produces biogas rich in methane, but also biogas containing a large amount of water vapor due to the initial moisture in the manure.

[0065] - Aquatic biomass: Materials such as algae and aquatic plants have high water content. When these biomass materials are used as feedstock for biogas production, the resulting gas can have a high water vapor content.

[0066] If the biogas source contains too much CH4, which is not conducive to efficient operation, additional CO2 can be introduced during the capture phase.

[0067] Various types of plasma reactors exist in the art for plasma-based gas conversion. The plasma reactor according to this disclosure is designed for efficient and stable operation in glow discharge mode, which is typically characterized by a lower plasma temperature compared to arc discharge mode. More specifically, the plasma reactor according to this disclosure is designed to generate stable glow discharge plasma to achieve high gas conversion performance, such as for the conversion of greenhouse gases. As mentioned above, reactions of particular interest are the DRM process for the simultaneous conversion of carbon dioxide and methane. While the plasma reactor according to this disclosure is particularly well-suited for operation in glow discharge mode, it may also operate in spark, arc, or transition discharge modes depending on specific operating settings (e.g., the power supply used) and gas flow patterns.

[0068] The plasma reactor used in this invention is preferably an atmospheric pressure plasma reactor, because they typically operate at atmospheric pressure.

[0069] In a preferred embodiment, the plasma reactor operates at atmospheric pressure.

[0070] In another or other embodiment, the plasma reactor is operated at a temperature of 2500K to 5000K, more preferably 3000K to 4500K, and most preferably about 3500K. This high temperature is preferably used to promote the reaction that leads to the formation of syngas.

[0071] In a preferred embodiment, the plasma reactor includes a plasma generating device selected from the following list: - Glide arc (GA) - Glow discharge - Radio frequency plasma (RF) - Microwave Plasma (MW) - Inductively Coupled Plasma (ICP) - Capacitively Coupled Plasma (CCP) - Dielectric barrier discharge (DBD).

[0072] In a more preferred embodiment, the plasma reactor includes a plasma generating device selected from the following list: - Glide arc (GA) - Glow discharge - Radio frequency plasma (RF) - Microwave Plasma (MW) - Dielectric barrier discharge (DBD).

[0073] Each of these reactor types possesses unique characteristics that can be used to improve the efficiency and effectiveness of the methane double reforming (BRM) process. In even more preferred embodiments, the plasma reactor includes a plasma generation device, which is a sliding arc (GA). Sliding arc reactors maintain stable discharge even at high flow rates. This characteristic is particularly advantageous in the case of BRM, where the flow rate of the gas mixture can be adjusted to optimize syngas production.

[0074] In another preferred embodiment, the plasma reactor includes a plasma generation device selected from sliding arc (GA) or glow discharge (GD) plasmas. These plasma types are particularly well-suited for direct plasma-driven gas reforming processes, including dry methane reforming (DRM), oxygen methane reforming, and bi-reforming methane (BRM). They can operate efficiently at atmospheric pressure while maintaining stable plasma conditions, enabling the high-conversion conversion of methane and carbon dioxide into syngas. Sliding arc and glow discharge plasmas promote efficient electron-driven dissociation of CH4 and CO2, facilitating the production of syngas in various reforming pathways without the need for catalysts. These plasma systems provide a versatile approach to reforming reactions, allowing optimization of the syngas composition by adjusting the CO2, O2, or H2O content in the input stream while maintaining high process efficiency and scalability.

[0075] Preferably, the plasma reactor is a closed-loop plasma reactor. A closed-loop plasma reactor ensures that the plasma discharge is confined to a controlled reaction environment, preventing undesirable interactions with external surfaces and maintaining consistent reaction conditions. More preferably, the plasma reactor is a closed-loop atmospheric pressure sliding arc or closed-loop atmospheric pressure glow discharge reactor. Compared to other types of plasma reactors, these reactor configurations have shown significantly higher conversion rates under direct plasma, non-catalytic conditions. Atmospheric pressure operation eliminates the need for a vacuum system, simplifies reactor design, and reduces energy consumption and maintenance requirements.

[0076] Furthermore, sliding arc and glow discharge plasma reactors offer several advantages over radio frequency (RF) and microwave (MW) plasma reactors. Specifically, GA and GD reactors exhibit simpler operating setups and require fewer specialized components (such as the complex impedance matching networks or waveguides necessary for RF and MW plasma systems). This simplicity translates into lower capital costs, easier scalability, and greater robustness for continuous operation. Additionally, GA and GD plasmas inherently generate moderate electron temperatures, which can efficiently drive DRM reactions without excessive energy loss, improving process sustainability.

[0077] By utilizing closed-loop atmospheric pressure sliding arc or glow discharge plasma reactors, this invention achieves an optimal balance between conversion efficiency, process stability, and system simplicity. These reactors enable a robust and scalable approach to direct plasma DRM, mitigating known challenges associated with plasma-catalyzed systems and maximizing the advantages of non-catalytic syngas production.

[0078] In a preferred embodiment, the plasma reactor is a closed-type atmospheric pressure glow discharge or sliding arc reactor, wherein the cathode-anode distance (defined as the shortest distance between the cathode and anode) is at least 10 mm, more preferably at least 20 mm, even more preferably at least 30 mm, even more preferably at least 40 mm, even more preferably at least 50 mm, even more preferably at least 60 mm, and most preferably at least 80 mm. In another preferred embodiment, the cathode-anode distance is at most 100 mm, more preferably at most 90 mm, even more preferably at most 80 mm, even more preferably at most 70 mm, even more preferably at most 60 mm, and most preferably at most 50 mm.

[0079] Increasing the distance between the anode and cathode raises the breakdown voltage in the plasma reactor, resulting in higher energy consumption per molecule of reformed gas. This increased energy input enhances the dissociation of CH4 and CO2, thereby improving conversion efficiency and syngas yield. A longer cathode-anode distance also prolongs the interaction time of the gases within the plasma region, which positively impacts the formation of CO and H2. However, excessive distance can lead to plasma discharge instability and increased electrode wear. Maintaining the cathode-anode distance within an optimized range of 50 mm to 80 mm allows for a balance between energy consumption, conversion efficiency, and plasma reactor stability, contributing to a robust and scalable reforming process.

[0080] In a preferred embodiment, the method involves causing the plasma reactor to operate at a rate of 1 L / min to 10 L / min. 6 Running at a flow rate of L / min.

[0081] In this embodiment, the plasma reactor is designed to handle a wide range of gas flow rates, thus making the system adaptable. Flow rate is a parameter in the operation of the plasma reactor that directly affects the residence time of the gas in the reactor, and consequently, the efficiency of the reforming reaction. The ability to operate at low flow rates (e.g., 1 L / min) makes this method suitable for small-scale operations where the amount of influent gas (e.g., biogas) produced is limited. Conversely, flow rates up to 10 L / min... 6 The ability to operate at high flow rates of L / min makes this method suitable for large-scale operations that generate large amounts of inlet gas (e.g., biogas).

[0082] In a more preferred embodiment, the plasma reactor is at 10 3 L / min to 10 5 Operating at a flow rate of L / min provides a balance between the residence time of the gas in the reactor and the efficiency of the reforming reaction.

[0083] The ability to operate the plasma reactor at varying flow rates allows this method to adapt to variable compositions of the influent gas stream (e.g., biogas). The composition of the biogas can vary depending on its source and the anaerobic digestion process. By adjusting the flow rate, this method can accommodate these variations while still producing syngas with the desired composition. This adaptability makes this method a versatile approach for producing methanol from biogas.

[0084] In a preferred embodiment, the specific energy input of the plasma reactor is at least 150 kJ / mol, preferably at least 200 kJ / mol.

[0085] In a preferred embodiment of the invention, the method is optimized by ensuring that the volume ratio of H2 to CO in the syngas obtained from the dry reforming process is 1.5 to 2.5, preferably 1.9 to 2.1. This optimal ratio is beneficial not only to the efficiency of methanol synthesis but also to the overall process efficiency and environmental impact. In a preferred embodiment of the invention, the method is optimized by ensuring that the volume ratio of H2 to CO in the syngas obtained from the dry reforming process is 1.0 to 3.0, preferably 1.2 to 2.8, more preferably 1.5 to 2.5, even more preferably 1.7 to 2.3, even more preferably 1.8 to 2.2, even more preferably 1.85 to 2.15, and most preferably 1.9 to 2.1. This optimal range is crucial for ensuring the efficiency of methanol synthesis and other hydrocarbon conversion processes, and is also crucial for optimizing the overall energy balance and environmental impact of the reforming process.

[0086] At the wider end of the range, when the H2 / CO ratio is 2.5 to 3.0, the syngas contains excess hydrogen, which can lead to poor carbon utilization and promote side reactions, such as the formation of methane via the Sabatier reaction. While higher hydrogen content can be advantageous for hydrogenation, additional CO supplementation or recycling is typically required to achieve the stoichiometric ratio needed for methanol production.

[0087] Conversely, when the H2 / CO ratio drops below 1.5, the syngas becomes hydrogen-poor, which can lead to incomplete methanol synthesis and increase the proportion of unreacted CO in the output stream.

[0088] As previously mentioned, the dry reforming process involves the reaction of methane and carbon dioxide in a plasma reactor. The resulting syngas is a mixture of carbon monoxide and hydrogen, which is subsequently preferably used for methanol production. Due to reaction (C), the optimal ratio for methanol synthesis is generally considered to be approximately 2:1.

[0089] Dry reforming of methane (DRM) can be enhanced by using catalysts that promote the conversion of methane and carbon dioxide into syngas (H2 and CO). Catalysts suitable for DRM typically include transition metal-based catalysts such as nickel (Ni), cobalt (Co), and iron (Fe), as well as noble metals such as platinum (Pt), palladium (Pd), rhodium (Rh), and ruthenium (Ru), often supported on materials such as alumina (Al2O3), cerium oxide (CeO2), zirconium oxide (ZrO2), or magnesium oxide (MgO). These catalysts help lower the activation energy of the reaction, increase conversion efficiency, and enhance selectivity for syngas formation. While noble metals generally offer greater stability and resistance to carbon deposition, their high cost makes nickel-based catalysts a more common choice due to their cost-effectiveness, despite their susceptibility to deactivation.

[0090] Preferably, the plasma reactor itself does not contain a catalyst. In a particularly preferred embodiment, the plasma reactor does not contain a fixed-bed catalyst. In another preferred embodiment, the plasma reactor does not contain a catalyst.

[0091] Plasma-based DRM operates under high-energy conditions that promote the dissociation of methane and carbon dioxide without the need for a catalyst.

[0092] A known limitation of catalytic DRM is catalyst deactivation, which can occur due to carbon deposition (coking), sintering of active metal sites, or poisoning by sulfur or other contaminants. Catalyst deactivation leads to persistent fluctuations in the H2 / CO ratio of the resulting syngas, which has profound implications for downstream processes, particularly in methanol synthesis, where precise control of the syngas composition is crucial. Furthermore, while plasma-catalytic reactors show significant potential for reaction enhancement, they are extremely difficult to operate in a continuous, stable, controlled, and scalable manner due to the complex interactions between the plasma-generated material and the catalyst surface.

[0093] More preferably, if a catalyst is used, it is placed downstream of the plasma reactor to optimize the composition of the syngas after plasma conversion. Even more preferably, the plasma and catalyst are contained separately to ensure a stable and controlled process, minimizing the risk of catalyst degradation caused by direct plasma exposure. This application aims to overcome the known problems of catalytic DRM by focusing on direct plasma DRM. This method eliminates the limitations associated with catalyst deactivation in the main conversion step, providing a more robust and stable approach for syngas production. The challenges associated with plasma-catalytic reactors can be partially mitigated by employing a two-stage system in which a catalytic reactor is connected in series after direct plasma DRM. In this configuration, the catalytic DRM reactor is primarily used to refine conversion efficiency and improve selectivity for the desired syngas composition. Furthermore, more preferably, a liquid trap is included between the plasma reactor and the catalytic reactor. This feature helps reduce catalyst deactivation by trapping condensate, heavy hydrocarbons, or other contaminants that could poison the catalyst. Advantageously, most of the DRM is carried out in a non-catalytic environment, which significantly extends catalyst lifetime and ensures a more stable and predictable syngas output.

[0094] In a preferred embodiment, the syngas generated in the plasma reforming step preferably contains at least 90% by volume, more preferably at least 95% by volume, even more preferably at least 98% by volume, even more preferably at least 99.0% by volume, even more preferably at least 99.5% by volume, and most preferably up to 99.9% by volume of CH4, CO2, CO, H2, and H2O. In another preferred embodiment, the syngas preferably contains at least 90% by volume, more preferably at least 95% by volume, even more preferably at least 98% by volume, even more preferably at least 99.0% by volume, even more preferably at least 99.5% by volume, and most preferably up to 99.9% by volume of CH4, CO2, CO, H2, and H2O. More preferably, the syngas is substantially composed of CH4, CO2, CO, H2, and H2O; even more preferably, it is substantially composed of CH4, CO2, CO, and H2, thereby minimizing the presence of foreign substances. In another preferred embodiment, the amount of byproducts (including heavier hydrocarbons and oxygenated compounds) is at most 2% by weight, more preferably at most 1% by weight, even more preferably at most 0.5% by weight, even more preferably at most 0.2% by weight, even more preferably at most 0.1% by weight, and most preferably at most 0.05% by weight.

[0095] Reformer reactors typically produce water, C 2+ Hydrocarbons and oxygenated hydrocarbons are byproducts. In the two-stage reactor setup of this invention, these byproducts should be minimized as much as possible to prevent operational problems in downstream processing. In particular, the formation of hydrocarbons such as acetylene (C2H2) and ethylene (C2H4) should be avoided, as these compounds significantly promote coking and reactor fouling, leading to instability in the plasma reactor and subsequent Fischer-Tropsch (FT) or methanol reactors.

[0096] Advantageously, the inventors have discovered that direct plasma DRM in sliding arc and glow discharge reactors can maintain the total amount of hydrocarbons and liquid fractions below 1%, significantly reducing the risk of carbon deposition and improving reactor life. This low byproduct formation allows for seamless coupling with downstream FT reactors or methanol reactors, ensuring stable operation and high syngas conversion efficiency. By carefully controlling plasma conditions, the present invention enables the production of clean, high-purity syngas compositions optimized for further processing, while minimizing process inefficiencies associated with undesirable side reactions.

[0097] In step c) of the method, the resulting syngas is supplied to a Fischer-Tropsch reactor (FT reactor).

[0098] A Fischer-Tropsch reactor, or FT reactor, is a chemical reactor used for Fischer-Tropsch synthesis, the process of converting syngas (a mixture of carbon monoxide (CO) and hydrogen (H2)) into liquid hydrocarbons, ranging from light fuels such as gasoline to heavier waxy substances. This reactor is designed to promote catalytic reactions under controlled temperature and pressure conditions, optimizing the conversion of syngas into hydrocarbons.

[0099] This invention specifically relates to a two-step process for methanol production, wherein the first step comprises plasma reforming of methane to produce syngas containing CO and H2; and the second step comprises feeding the syngas into a separate Fischer-Tropsch reactor (preferably a methanol reactor) to convert the syngas into methanol. This dual-reactor setup offers significant advantages over a single-reactor configuration, particularly in terms of process flexibility, efficiency, and product separation.

[0100] A key advantage of this two-step approach is the ability to independently optimize the operating conditions of each reactor. Plasma reforming of methane is most efficient at or near atmospheric pressure, as higher pressures disrupt plasma formation and reduce conversion efficiency. In contrast, the methanol reactor operates optimally at elevated pressures (preferably above 50 bar) to enhance methanol synthesis kinetics and increase single-pass conversion. By maintaining separate reactors, each stage can be individually fine-tuned for maximum efficiency without compromising the conditions required for the other step.

[0101] Another key benefit is the improved ability to separate and recycle unreacted gases. Methanol reactors produce both liquid methanol and a gaseous fraction containing unreacted CO, H2, and byproducts such as CO2. In this invention, the methanol reactor output can be effectively separated into liquid and gas phases, allowing the gaseous fraction to be recycled back to the methanol reactor for further improved conversion efficiency. This gas recirculation is not feasible in single-reactor setups because plasma reforming and methanol synthesis would occur in the same environment, leading to low reactant utilization and product dilution.

[0102] Furthermore, separating the plasma reforming step from the methanol synthesis step provides greater operational stability and scalability. The dual-reactor system allows for better control of the syngas composition and reduces H2 / CO ratio fluctuations that can negatively impact methanol yield. Moreover, by decoupling the two stages, each reactor can be designed with materials and configurations best suited to its respective reaction conditions, thereby increasing reactor life and reducing maintenance requirements. This modular approach ultimately improves process efficiency, enhances methanol yield, and provides a more robust and scalable pathway to sustainable methanol production.

[0103] In a particularly preferred embodiment, the FT reactor is a methanol reactor, such that the resulting syngas is supplied to the methanol reactor in step b), wherein the CO and H2 in the syngas are at least partially converted into methanol in the methanol reactor.

[0104] In a particularly preferred embodiment, the method includes the following steps: a. Supplying one or more gaseous input streams to the plasma reactor, wherein the one or more gaseous input streams contain at least CO2 and CH4; b. Ignite the plasma in the plasma reactor, thereby causing CO2, H2O, and CH4 to react and form a syngas containing CO and H2; and c. The syngas is supplied to a methanol reactor, wherein the CO and H2 in the syngas are at least partially converted into methanol in the methanol reactor.

[0105] The FT reactor is designed to operate under conditions favorable to the conversion of syngas into desired fuel products, such as methanol. The temperature in the FT reactor is preferably from 150°C to 350°C, more preferably from 200°C to 300°C, and most preferably from 220°C to 300°C. The pressure in the methanol reactor can be from 20 to 200 bar, more preferably from 50 to 100 bar.

[0106] The output stream of an FT reactor contains liquid fuel products and optional unreacted gaseous products. In the case of a methanol reactor, the output of the methanol reactor contains at least methanol and optional unreacted gaseous products such as CO, CO2, and H2.

[0107] In a preferred embodiment, an output stream containing the methanol is extracted from the methanol reactor, wherein the output stream is supplied to a separation tank in which unreacted gaseous products such as CO2, CO and H2 are separated from the liquid phase.

[0108] Separators utilize the differences in physical properties (such as boiling point and density) between these components to separate the gas and liquid phases. The reactor effluent is preferably fed into the separator via a fluid connection. The separator is a vessel designed to allow the mixed flow to settle and separate into two different phases. • Top layer (gas phase): This layer contains unreacted gases and may contain some vapors of products (methanol) and byproducts (such as water).

[0109] • Bottom layer (liquid phase): This layer consists primarily of liquid methanol and optionally water and any heavier compounds present in the mixture.

[0110] In another preferred embodiment, the gas phase rich in unreacted hydrogen, carbon monoxide, and carbon dioxide is recycled back to the methanol reactor for further conversion. This recycling process helps improve overall conversion efficiency by giving the unreacted gases another chance to react.

[0111] In another preferred embodiment, the liquid phase is supplied to a separation tower, wherein the methanol is separated from the liquid phase. The methanol is also separated from other liquid products in the liquid phase.

[0112] The liquid phase, which contains at least methanol, is preferably sent to a distillation column or another separation unit. Here, the methanol is separated from water and any other impurities to produce a high-purity methanol product.

[0113] In another or another preferred embodiment, the liquid phase further comprises water, wherein the liquid phase is supplied to the separation unit, and wherein at least the water and the methanol are separated.

[0114] In another aspect, the present invention can be described as a method for optimizing syngas. In this document, the embodiments of steps a) and b) described above correspond to embodiments of this method.

[0115] The method includes the following steps: a. Supplying one or more gaseous input streams to the plasma reactor, wherein the one or more gaseous input streams contain at least CO2, H2O, and CH4; and b. Ignite the plasma in the plasma reactor, thereby causing the CO2, H2O and CH4 to react and form a synthesis gas containing CO and H2.

[0116] In a particularly preferred embodiment, the volume ratio of the total amount of CH4 to the total amount of CO2 contained in the one or more gaseous input streams is at least 2.

[0117] The volume ratio of H2 to CO in the synthesis gas is preferably 1.5 to 2.5.

[0118] In a second aspect, the present invention relates to a system for hydrocarbon production, preferably methanol production.

[0119] The system preferably includes: - A plasma reactor comprising a plasma reactor chamber having a plasma region, the plasma reactor being configured to ignite plasma in the plasma region, the plasma reactor further comprising a plasma inlet for a gaseous input stream and a plasma outlet for a gaseous output stream; and - A methanol reactor comprising a reactor chamber, the methanol reactor further comprising a methanol reactor inlet for a gaseous input flow and a methanol reactor outlet for a liquid output flow.

[0120] In a particularly preferred embodiment, the plasma outlet is fluidly connected to the inlet of the methanol reactor.

[0121] In this system, a direct fluid connection is established between the plasma reactor outlet and the methanol reactor inlet, providing significant benefits for the conversion of greenhouse gases into methanol. This configuration ensures that the synthesis gas (syngas) from the plasma reactor (a mixture of CO2 and hydrogen carrier converted to H2 and CO) flows seamlessly and continuously directly into the methanol reactor for immediate conversion into methanol. This direct connection minimizes the exposure of the synthesis gas to atmospheric pollutants and reduces the risk of gas composition changes that may occur between stages due to cooling or interaction with the external environment. It improves the efficiency of the entire process by maintaining suitable temperature and pressure conditions favorable to the chemical reactions involved, thereby increasing the yield and purity of the produced methanol. Furthermore, it simplifies system design, reducing the need for additional piping, valves, and intermediate storage, which in turn reduces capital and operating costs. Integrating these reactors into a streamlined process fully utilizes the high reactivity and energy efficiency of plasma-assisted conversion, resulting in a more compact, efficient, and environmentally friendly methanol production system.

[0122] In another preferred embodiment, the system optionally includes a liquid trap or separator fluidly connected between the plasma reactor and the methanol reactor. More preferably, syngas is passed from the plasma reactor to the methanol reactor; however, a small amount of liquid fraction is separated. This separation stage is included to remove liquid components and solid impurities before introducing the syngas into the methanol reactor. Preferably, the liquid trap or separator is configured to separate condensate, unreacted hydrocarbons, and any entrained particles that may form during plasma reforming. More preferably, the separator is designed to operate passively, relying on phase behavior differences rather than requiring additional energy-consuming separation processes.

[0123] Advantageously, this intermediate separation step reduces the accumulation of liquid and solid impurities within the methanol production loop, thereby limiting the buildup of undesirable byproducts that might otherwise require complex downstream purification. By removing contaminants before the syngas enters the methanol reactor, this implementation significantly reduces reactor fouling, extends catalyst lifetime, and minimizes the risk of deactivation associated with coke or heavy hydrocarbon deposition. Furthermore, removing excess water before methanol synthesis ensures the H2 / CO ratio remains within a preferred range, optimizing methanol yield and selectivity. These benefits are achieved without a comprehensive gas purification stage, thus avoiding the high energy costs typically associated with conventional gas-liquid separation units. Therefore, introducing a liquid trap or separator provides an efficient, low-energy solution for maintaining reactor performance, ensuring process stability, and improving overall methanol production efficiency.

[0124] In a preferred embodiment, the methanol reactor is a fixed-bed catalytic reactor configured to hydrogenate carbon monoxide and carbon dioxide into methanol. The reactor preferably includes a reaction chamber containing a heterogeneous catalyst, wherein the catalyst is preferably selected from copper-based catalysts, more preferably Cu / ZnO / Al₂O₃, and even more preferably modified Cu / ZnO-based catalysts with enhanced thermal stability and resistance to deactivation. The methanol reactor is preferably designed to operate at elevated pressures to optimize conversion efficiency and maintain catalyst performance over extended operating periods.

[0125] In a preferred embodiment, the methanol reactor is operated at a pressure of at least 50 bar, more preferably at least 70 bar, even more preferably at least 80 bar, even more preferably at least 90 bar, and most preferably 90 to 100 bar. Operating at high pressure increases the conversion of syngas to methanol by shifting the reaction equilibrium towards methanol synthesis, thereby improving single-pass efficiency. In another preferred embodiment, the methanol reactor is operated at a temperature of at least 150°C, more preferably at least 180°C, even more preferably at least 200°C, even more preferably at least 220°C, and most preferably 220 to 280°C. These temperatures ensure optimal catalytic activity while minimizing undesirable side reactions (e.g., excess water formation or catalyst sintering).

[0126] In a preferred embodiment, the system further includes a separation tank fluidly connected to the reactor outlet, wherein the tank separation stage includes a tank outlet for a gas output stream and a tank outlet for a liquid output stream.

[0127] The system includes a separator tank fluidly connected to the reactor outlet, introducing an intermediate step that enhances the separation of the gas and liquid phases generated during methanol synthesis. This separator tank is equipped with outlets for both the gas and liquid output streams, allowing for the efficient separation of unreacted gases from the resulting methanol and water mixture. This separation is crucial for recycling the gases back to the methanol reactor, thereby improving the overall efficiency and yield of the methanol production process by ensuring that as much of the reactant gas as possible is converted into methanol.

[0128] In a preferred embodiment, the tank outlet for the gas output stream is fluidly connected to the methanol reactor inlet of the methanol reactor. The gas output stream from the separator is fluidly connected back to the methanol reactor inlet. This configuration is advantageous because it allows unreacted gas to be directly recycled back into the reactor for further conversion. This recycling loop significantly improves process efficiency, minimizes waste, and reduces the need for fresh feedstock, thereby making the operation more sustainable and cost-effective.

[0129] In a preferred embodiment, the tank outlet for the liquid output stream is fluidly connected to the inlet of a separation column suitable for separating liquid synthesis products. Connecting the tank outlet for the liquid output stream to the inlet of a separation column specifically designed to separate methanol from the liquid phase expands the system's functionality. This arrangement ensures the efficient purification of the methanol-water mixture, with methanol separated to meet product quality standards. The direct connection between the tank and the separation column simplifies the process, reduces potential loss or contamination of the product stream, and ensures methanol is produced at the highest possible purity. This step is crucial for the production of commercial-grade methanol, suitable for a wide range of applications including fuels, solvents, and industrial chemicals, enhancing the system's versatility and the marketability of the produced methanol.

[0130] The invention will now be described in more detail with reference to non-limiting embodiments.

[0131] Embodiments and accompanying drawings

[0132] To better illustrate the features of the invention, several preferred applications based on the invention for inspecting the condition of slurry used in mechanical connections are described below by way of example (in no way limiting its potential applications), wherein: Figure 1 An embodiment of the present invention is illustrated herein.

[0133] Methane and carbon dioxide are supplied to plasma reactor 101, where methane is dry reformed according to reaction (B) to obtain syngas 102 containing CO and H2.

[0134] (B)

[0135] CO2 and hydrogen carriers can be captured from industrial and agricultural processes. Capture technologies are considered background technologies and may include the following methods: • Adsorption (chemisorption, physisorption) • Adsorption (Pressure Swing Adsorption (PSA), Metal-Organic Framework (MOF)) Low-temperature distillation ·membrane Chemical chain When the resulting syngas is preferably used to produce methanol according to reaction (D), the optimal molar ratio of CO to H2 in the syngas is 1:2.

[0136] (C)

[0137] Methanol production according to one embodiment of the present invention is shown in Figure 2In the plasma unit 201, a mixture of hydrogen source 204 and CO2 203 is fed. In this embodiment of the invention, the synthesis gas stream 202 can be directly converted into fuel or olefins 207 via a Fischer-Tropsch reactor 206. The production of methanol (MeOH) is particularly attractive to the chemical and maritime industries.

[0138] In a methanol reactor, the following reaction occurs under controlled pressure and temperature: CO2 + 3H2 → CH3OH + H2O ΔH = -50 kJ / mol CO + 2H2 → CH3OH ΔH = -91 kJ / mol CO2 + H2 → CO + H2O ΔH = 41 kJ / mol As can be seen, water is an undesirable product in the final stream. Furthermore, the feed gas does not completely convert to liquid, therefore a separator is used—all unreacted gases are returned to the reactor. The mixture of MeOH and water is then fed into a separation (distillation) column, which separates the final product into two streams: pure MeOH and excess water. This is illustrated in… Figure 3 middle.

[0139] In plasma unit 301, a mixture of hydrogen source 304 and CO2 303 is fed. In this embodiment of the invention, the synthesis gas stream 302 can be directly converted into fuel or olefins 307 via Fischer-Tropsch reactor 306. The product from Fischer-Tropsch reactor 306 is supplied to separator 308 to separate unreacted gas 309, which is then returned to Fischer-Tropsch reactor 306. The unreacted gas may, for example, contain CO2, CO, and / or H2. A mixture 313 of methanol and water is fed to separator 310, which separates the final product into a water stream 311 and a methanol stream 312.

[0140] Obviously, the methods and applications of the present invention are not limited to the embodiments presented.

Claims

1. A method for producing methanol, wherein the method comprises the following steps: a. Supplying one or more gaseous input streams to the plasma reactor, wherein the one or more gaseous input streams contain at least CO2 and CH4; b. Ignite the plasma in the plasma reactor to dry reform the CH4 to form a syngas containing CO and H2; c. The syngas is supplied to a methanol reactor, wherein the CO and H2 in the syngas are at least partially converted into a liquid phase containing at least methanol. The plasma reactor and the methanol reactor are fluidly connected, and the volume ratio of the total amount of CH4 to the total amount of CO2 contained in the gaseous input stream is at least 2.

2. The method of claim 1, wherein the methanol reactor is operated at a pressure of 50 bar to 100 bar.

3. The method as described in any of the preceding claims, wherein the methanol reactor is operated at a temperature of 220°C to 300°C.

4. The method of any of the preceding claims, wherein an output stream containing the methanol is extracted from the methanol reactor, and wherein the output stream is supplied to a separation tank, wherein unreacted gaseous products such as CO2, CO and H2 are separated from the liquid phase.

5. The method of claim 4, wherein the unreacted gaseous products are recycled to the plasma reactor.

6. The method of claim 4 or 5, wherein the liquid phase is supplied to a separation tower, wherein the methanol is separated from the liquid phase.

7. The method of any of the preceding claims, wherein the liquid phase further comprises water.

8. The method for methanol production as described in any of the preceding claims, wherein the volume ratio of H2 to CO in the synthesis gas is 1.5 to 2.

5.

9. The method of any of the preceding claims, wherein the liquid phase further comprises water, and wherein the liquid phase is supplied to a separation unit, wherein at least the water and the methanol are separated.

10. The method of any of the preceding claims, wherein the CO2 is captured by adsorption, cryogenic distillation, membrane or chemical chaining.

11. The method of any of the preceding claims, wherein the gaseous input stream comprises CH4 derived from the following list: fossil fuels, biogas, syngas, or a gas mixture obtained by hydrogenation of CO2.

12. A system for methanol production, comprising: - A plasma reactor comprising a plasma reactor chamber having a plasma zone, the plasma reactor being configured to ignite plasma in the plasma zone, the plasma reactor further comprising a plasma inlet for a gaseous input stream and a plasma outlet for a gaseous output stream; - A methanol reactor, comprising a reactor chamber, the methanol reactor further comprising a methanol reactor inlet for a gaseous input flow and a methanol reactor outlet for a liquid output flow. The plasma outlet is fluidly connected to the inlet of the methanol reactor.

13. The system of claim 12, wherein the system further comprises a separator in fluid connection with the outlet of the methanol reactor, wherein the separator comprises a tank outlet for a gas output stream and a tank outlet for a liquid output stream.

14. The system of claim 13, wherein the tank outlet for the gas output stream is fluidly connected to the methanol reactor inlet of the methanol reactor.

15. The system of claim 13 or 14, wherein the tank outlet for the liquid output stream is fluidly connected to the inlet of a separation tower adapted to separate methanol from the liquid phase.

16. Use of the system as described in any one of claims 12 to 15 for methanol production.

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