Synthetic methanol with low deuterium content from non-fossil resources

Abstract

A process for manufacturing methanol having a deuterium content of less than 90 ppm based on the total hydrogen content, the process comprising the steps of: (a) providing hydrogen having a deuterium content of less than 90 ppm based on the total hydrogen content by water electrolysis using power generated at least in part from non-fossil renewable resources; (b) providing carbon dioxide; (c) reacting hydrogen and carbon dioxide in the presence of a catalyst to form methanol.

Description

[0001] The present invention relates to a process for producing methanol having a deuterium content of less than 90 ppm based on the total hydrogen content, the methanol obtained therefrom and the use thereof.

[0002] In the chemical industry, methanol serves as a feedstock for the production of olefins, formaldehyde, acetaldehyde, acetic acid, methyl acetate, acetic anhydride, and vinyl acetate. Conventional production methods involve catalytic processes using fossil feedstocks such as natural gas or coal.

[0003] Synthesis gas (syngas) used to produce methanol can be produced from many sources including natural gas, coal, biomass or nearly any hydrocarbon feedstock by reaction with steam (steam reforming), carbon dioxide (dry reforming) or oxygen (partial oxidation).

[0004] Synthesis gas is produced, for example, from solid raw materials by coal gasification. Coal is thus reacted in a mixture that is partially oxidized with air or pure oxygen and gasified with water vapor to give a mixture of carbon monoxide and hydrogen. Carbon monoxide is in equilibrium with carbon and carbon dioxide by the Boudouard equilibrium.

[0005] 2C+O2→2CO,

[0006] C+H2O2CO+H2,

[0007]

[0008] In addition, the water-gas shift reaction must also be considered.

[0009]

[0010] The exothermic reaction with oxygen provides the necessary energy to achieve the high reaction temperatures for the endothermic gasification reaction of the carbon with water vapor.

[0011] In principle, in addition to coal, other solid raw materials (wood, straw) can be used instead.

[0012] The most important gaseous product for the production of synthesis gas is natural gas, which is reacted with water vapor by steam reforming. Natural gas provides the highest hydrogen to carbon monoxide ratio

[0013] CH4+H2O→CO+3H2,

[0014] In addition, liquid educts (such as light naphtha fractions) can be reacted with water vapor by steam reforming after desulfurization.

[0015] To produce methanol, the ratio of carbon monoxide to hydrogen in the syngas is adjusted to satisfy the following reaction equation

[0016] CO + 2H2 → CH3OH,

[0017] Synthesis gas is mainly produced by steam reforming or partial oxidation of natural gas or by coal gasification. Although in North America and Europe, natural gas is used for methanol production, in China and South Africa, synthesis gas production is mainly based on coal. According to the ratio of carbon monoxide to hydrogen, the product gas is referred to as water gas (CO+H2), synthesis gas (CO+2H2) or cracking gas (spaltgas) (CO+3H2). The cracking gas can be made hydrogen-poor or carbon monoxide-rich (for example, by adding carbon dioxide and removing water via water-gas shift reaction), and water gas can be made hydrogen-rich or carbon monoxide-poor, so as to obtain synthesis gas.

[0018] The synthesis of methanol from CO2 is less exothermic than starting with syngas, and it also involves the reverse water gas shift (RWGS) as a secondary reaction. To facilitate methanol synthesis, the CO in the syngas is converted to CO2 via the water gas shift (WGS) reaction.

[0019] CO2+3H2→CH3OH+H2O ΔH298K=-49.5 kJ mol-1

[0020] CO2+H2→CO+H2O ΔH298K=41.2 kJ mol-1

[0021] If the CO2 comes from a suitable direct or indirect biogenic source, the above water-gas equilibrium provides the basis for the production of CO2-neutral methanol. According to the reverse water-gas shift (RWGS) reaction, there is an opportunity to directly include biogenic CO2 in a suitable synthesis gas-methanol-process. The synthesis gas is then converted into methanol using a CuO / ZnO / Al2O3 catalyst, for example at a temperature of 250°C-300°C and a pressure range of 5-10 MPa.

[0022] In this sense, CO2 from different biological carbon sources can be included in the synthesis gas to form methanol. The biological source of CO2 can come from a fermentation process of biological materials, a combustion process of waste of biomass or bio-based materials, or from an extraction process of atmospheric CO2, for example by an extractive regeneration process step (such as amino CO2 scrubbing).

[0023] Of course, mixtures of CO2 from biogenic and fossil carbon sources can also be mixed for the production of methanol.

[0024] 12 The natural isotopic abundance of C is about 98.9%. 13 The natural isotopic abundance of C is about 1.1%. 13 C / 12C isotope ratios are given relative to the international standard Vienna-Pee-Dee-Belemnite standard (V-PDB). 13 C / 12 C isotope ratios are expressed in δ 13 C values ​​are given in ‰. By definition, a standard has a δ 13 C value. Higher than the standard 13 The C content of the material has a positive ‰ value and is lower than the standard 13 C-content materials have negative ‰ values.

[0025] In physical organic chemistry, the kinetic isotope effect is the change in the reaction rate of a chemical reaction when one of the atoms in the reactants is replaced by one of its isotopes. Formally, it involves the L ) and weight (k H ) isotope substitution reaction rate constant ratio k L / k H This change in reaction rate is a quantum mechanical effect that is primarily caused by the fact that heavier isotopologues have lower vibrational frequencies than their lighter counterparts. In most cases, this means that a greater energy input is required for the heavier isotopologue to reach the transition state, and therefore the reaction rate is slower.

[0026] Isotope rate changes are most pronounced when the relative mass change is greatest, since the effect is related to the vibrational frequency of the bonds affected. For example, changing a hydrogen atom (H) to its isotope deuterium (D) represents a 100% increase in mass, whereas changing 13 C Replacement 12 C, the mass increases by only 8%. The reaction rates involving C-H bonds are typically 6-10 times faster than those involving the corresponding CD bonds, while 12 C reaction is only slightly higher than the corresponding 13 C reacts 4% faster.

[0027] A primary kinetic isotope effect may be found when bonds to isotopic atoms are formed or broken. A secondary kinetic isotope effect is observed when bonds to isotopic atoms in the reactants are not broken or formed. The secondary kinetic isotope effect tends to be much smaller than the primary kinetic isotope effect; however, the secondary deuterium isotope effect can be as large as 1.4 / deuterium atom.

[0028] The object of the present invention is to provide an environmentally friendly method for producing methanol. Another object of the present invention is to provide methanol with a low deuterium content. The favorable kinetic isotope effect caused by the low deuterium content of methanol can be cumulative because it is also present in subsequent production steps further downstream in the value chain.

[0029] This object is solved by a process for producing methanol having a deuterium content of less than 90 ppm based on the total hydrogen content, comprising the following steps:

[0030] (a) providing hydrogen having a deuterium content of less than 90 ppm by water electrolysis using electricity generated at least in part from non-fossil renewable resources;

[0031] (b) providing carbon dioxide;

[0032] (c) reacting hydrogen and carbon dioxide in the presence of a catalyst to form methanol.

[0033] Fossil-based methanol from syngas typically has a δ in the range of -50‰ to -25‰ 13 C value, which depends on the fossil feedstock. Methanol based on CO2 captured from ambient air typically has a δ in the range of -10‰ to -2.5‰ 13 C value, which corresponds to the delta of carbon dioxide captured from ambient air 13 C value.

[0034] In a preferred embodiment of the method of the present invention, the carbon dioxide provided in step (b) has a δ corresponding to > -20‰ 13 C value 13 In particular, the carbon dioxide provided in step (b) has a δ 13 C value 13 C content.

[0035] Therefore, if CO2 is captured from ambient air, the 13 The C content corresponds to a δ of typically > -20‰ 13 C values, more specifically corresponding to δ between -10‰ and -2.5‰ 13 C value.

[0036] The invention also relates to methanol having a deuterium content of less than 90 ppm based on the total hydrogen content. Preferably, the deuterium content is from 30 to 75 ppm based on the total hydrogen content.

[0037] The deuterium content of hydrogen and hydrogen-containing compounds is herein expressed as the total hydrogen content (protium 1 H and deuterium 2 The atomic ppm of the total atoms of H) is given.

[0038] Methanol with a deuterium content of less than 90 ppm, preferably 30 to 75 ppm, based on the total hydrogen content can be used to produce ethylene. Typically, the ethylene obtained also has a low deuterium content of less than 90 ppm, preferably 30 to 75 ppm. If carbon dioxide is captured from ambient air, the ethylene obtained is 13The C content also corresponds to a δ of typically >-20‰ 13 C values, more specifically corresponding to δ between -10‰ and -2.5‰ 13 C value.

[0039] Water electrolysis is an environmentally friendly method for producing hydrogen because it uses renewable H2O and produces only pure oxygen as a byproduct. In addition, water electrolysis utilizes direct current (DC) from sustainable energy sources such as solar, wind, hydro, and biomass.

[0040] It is observed that the deuterium atom content of hydrogen produced by electrolysis of water is lower than that of hydrogen produced by petrochemical means (e.g., hydrogen contained in synthesis gas), typically lower than 90 ppm, preferably 30 to 75 ppm. The deuterium atom content of hydrogen produced by electrolysis can be as low as 15 ppm. Deuterium exists mainly in the form of DH rather than D2.

[0041] One suitable water electrolysis method is alkaline water electrolysis. Hydrogen production by alkaline water electrolysis is a mature technology with commercial levels up to the megawatt range. In alkaline water electrolysis, initially on the cathode side, two water molecules of an alkaline solution (KOH / NaOH) are reduced to one hydrogen molecule (H2) and two hydroxide ions (OH - The generated H2 is emitted from the cathode surface in gaseous form, and hydroxide ions (OH - ) migrates through the porous diaphragm to the anode under the influence of the electric field between the anode and the cathode, where the hydroxide ions are discharged into half molecular oxygen (O2) and one molecule of water (H2O). Alkaline electrolysis operates at a relatively low temperature (such as 30°C-80°C), with an alkaline aqueous solution (KOH / NaOH) as the electrolyte, and the concentration of the electrolyte is about 20% to 30%. The diaphragm in the middle of the electrolytic cell separates the cathode and the anode and also separates the generated gases from their corresponding electrodes, thereby avoiding mixing of the generated gases. However, alkaline electrolysis has negative aspects, such as limited current density (less than 400mA / cm 2 ), low operating pressure and low energy efficiency.

[0042] In a preferred embodiment of the process of the invention, the hydrogen is provided by polymer electrolyte membrane water electrolysis. Variants of polymer electrolyte membrane water electrolysis are proton exchange membrane water electrolysis (PEMWE) and anion exchange membrane water electrolysis (AEMWE).

[0043] PEM water electrolysis was developed to overcome the shortcomings of alkaline water electrolysis. PEM water electrolysis technology is similar to PEM fuel cell technology (which uses a solid polysulfonated membrane As electrolyte (proton conductor). These proton exchange membranes have many advantages, such as low gas permeability and high proton conductivity (0.1 ± 0.02 S cm -1 ), low thickness (20-300 μm), and allows high-voltage operation. From the perspective of sustainability and environmental impact, PEM water electrolysis is one of the most advantageous methods for converting renewable energy into high-purity hydrogen. PEM water electrolysis has great advantages, such as compact design, high current density (above 2A cm -2 ), high efficiency, fast response, operation at low temperature (20℃-80℃) and production of ultrapure hydrogen. The state-of-the-art electrocatalysts for PEM water electrolysis are highly active precious metals such as Pt / Pd for the cathode hydrogen evolution reaction (HER) and IrO2 / RuO2 for the anode oxygen evolution reaction (OER).

[0044] One of the biggest advantages of PEM water electrolysis is its ability to operate at high current densities. This can lead to reduced operating costs, especially for systems coupled to very dynamic energy sources such as wind and solar, where sudden peaks in energy output would otherwise result in uncaptured energy. Polymer electrolytes allow PEM water electrolyzers to operate with very thin membranes (approximately 100-200 μm) while still allowing high operating pressures, resulting in low ohmic losses (which are primarily caused by the conduction of protons across the membrane (0.1 S / cm)) and compressed hydrogen output.

[0045] The PEM water electrolyzer utilizes a solid polymer electrolyte (SPE) to conduct protons from the anode to the cathode while electrically insulating the electrodes. Under standard conditions, the enthalpy required to form water is 285.9 kJ / mol. Part of the energy required for the ongoing electrolysis reaction is supplied by thermal energy, and the remainder is supplied by electrical energy.

[0046] The half-reaction occurring on the anode side of a PEM water electrolyzer is generally referred to as the oxygen evolution reaction (OER). Here, liquid water reactant is supplied to a catalyst where it is oxidized into oxygen, protons, and electrons.

[0047] The half-reaction that occurs on the cathode side of a PEM water electrolyzer is often referred to as the hydrogen evolution reaction (HER). Here, protons that have moved across the membrane are reduced to gaseous hydrogen.

[0048] PEMs can be made of pure polymer membranes or composite membranes in which other materials are embedded in the polymer matrix. One of the most common and commercially available PEM materials is the fluoropolymer PFSA or (a product of DuPont). Although is an ionomer with a fully fluorinated backbone like Teflon, but there are many other structural motifs used to make ionomers for proton exchange membranes. Many use polyaromatic polymers, while others use partially fluorinated polymers.

[0049] An overview of hydrogen production by PEM water electrolysis is given by S. Kumar and V. Himabindu in Material Science for Energy Technologies 2 (2019), pp. 4442-4454.

[0050] An overview of hydrogen production by anion exchange membrane water electrolysis is given by HAMiller et al. in Sustainable Energy Fuels, 2020, 4, pp. 2114-2133.

[0051] K. Harada et al., International Journal of Hydrogen Energy 45 (2020), pp. 31389-31395, reported a 2- to 3-fold deuterium depletion in polymer electrolyte membrane water electrolysis. Corresponding to a stoichiometric number λ between 4 and 9 for a given water mass flow rate in the anode, it was found that at current densities of 1.0 to 2.0 A cm -2 In the case of

[0052] β=([H] / [D]) 气体 / ([H] / [D]) 液体

[0053] Between 2 and 3, where "gas" is the evolved gas and "liquid" is the water before electrolysis. The stoichiometric number λ is defined as follows:

[0054] λ=V xρ / (J / 2F x 60x M H2O )

[0055] Where V (mL min -1 ) is the water mass flow rate in the anode, F is the Faraday constant, J is the electrolysis current (A), and ρ is the density of water (g mL -1 ) and M H2O (g mol -1 ) is the molar weight of water. A stoichiometric number λ of 10 means that at a given electrolysis current, the amount of fresh water supplied to the anode can be 10 times the amount theoretically consumed by electrolysis.

[0056] H. Sato et al., International Journal of Hydrogen Energy 46 (2021), pp. 33 689-33 695, reported that for anion exchange membrane water electrolysis, at λ = 4, the deuterium concentration in the escaping hydrogen was diluted by about 1 / 5 relative to the feed water.

[0057] Therefore, with respect to the feed water in the polymer electrolyte membrane water electrolysis, the deuterium in the hydrogen that escapes can be easily depleted by a factor of 2 to 5. Depending on the electrolysis conditions (water flow, current density), even higher depletion factors are possible. Since the average deuterium content of water is about 150 ppm based on the total hydrogen content, the hydrogen provided in step (a) of the method of the present invention can have a deuterium content of 30 to 75 ppm, or even lower, based on the total hydrogen content.

[0058] The electricity is at least partially generated from non-fossil renewable resources. In other words, part of the electricity can still be generated from fossil fuels, preferably from natural gas, because the combustion of natural gas leads to much lower carbon dioxide emissions per megajoule of electrical energy than the combustion of coal. However, the portion of electrical energy generated from fossil fuels should be as low as possible, preferably ≤50%, preferably ≤30%, most preferably ≤20%.

[0059] The electricity from non-fossil resources used in the water electrolysis according to the invention can be generated by nuclear energy. The European Commission considers nuclear energy to be renewable as long as certain preconditions are met (ie safe long-term storage of nuclear waste).

[0060] The electricity from non-fossil resources used in the water electrolysis according to the present invention is preferably generated by wind, solar, biomass, hydro and geothermal energy.

[0061] In a preferred embodiment of the method of the present invention, the electricity used in the electrolysis of water is generated by hydropower. There are many forms of hydropower. Traditionally, hydropower comes from building large hydroelectric dams and reservoirs. Small hydropower systems are hydroelectric facilities that typically produce up to 50MW of power. They are usually used for small rivers, or as low-impact development for larger rivers. Run-of-the-river hydropower plants obtain energy from rivers without creating large reservoirs. Water is typically transported along the side of a river valley (using channels, pipes and / or tunnels) until it is above the valley floor, and then it can be allowed to fall through a channel to drive a turbine.

[0062] Wave power, which captures the energy of ocean surface waves, and tidal power, which converts tidal energy, are two forms of hydropower with future potential.

[0063] In a further preferred embodiment of the method of the present invention, the electricity used in the electrolysis of water is generated by wind power. Wind power can be used to operate wind turbines. Modern utility-scale wind turbines have power ratings ranging from about 600kW to 9MW. The power available from the wind is a function of the cube of the wind speed, so as wind speed increases, the power output increases until the maximum output of a particular turbine. Areas with stronger and more constant winds, such as offshore and high-altitude sites, are preferred locations for wind farms.

[0064] In a further preferred embodiment of the method of the invention, the electricity used in the water electrolysis is generated by solar energy, particularly preferably by a photovoltaic system. Photovoltaic systems convert light into direct current (DC) by utilizing the photoelectric effect. Concentrated solar power (CSP) systems use lenses or mirrors and tracking systems to focus sunlight from a large area into a small beam. CSP-Stirling currently has the highest efficiency of all solar technologies.

[0065] In another preferred embodiment of the method of the present invention, the electricity used in the water electrolysis is produced by biomass. Biomass is a biological material derived from a living or recently living organism. It most commonly refers to a material of plant or plant origin (which is specifically referred to as lignocellulosic biomass). As an energy source, biomass can be used to generate heat or electricity directly by burning, or indirectly after it is converted into various forms of biofuels. The conversion of biomass into biofuels can be achieved by different methods, which are roughly divided into: thermal, chemical and biochemical methods. As of 2012, wood is the largest biomass energy source; examples include forest residues (such as dead trees, branches and stumps), yard prunings, wood chips and even municipal solid waste. Industrial biomass can be grown from various types of plants, including miscanthus, switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane, bamboo and various tree species ranging from eucalyptus to oil palm (palm oil).

[0066] Plant energy is produced from crops grown specifically for use as fuel, which provide high biomass output per hectare for low energy input. Grains can be used for liquid transport fuels, while straw can be burned to produce heat or electricity. Biomass can be converted into other usable forms of energy (such as methane gas) or transport fuels (such as ethanol and biodiesel). Rotting garbage and waste from agriculture and humans release methane gas - also known as landfill gas or biogas. Crops (such as corn and sugar cane) can be fermented to produce the transport fuel ethanol. Biodiesel (another transport fuel) can be produced from surplus food products (such as vegetable oils and animal fats).

[0067] In step (b) of the process of the invention, carbon dioxide is provided. In a preferred embodiment, the carbon dioxide provided in step (b) is captured from industrial flue gases or from ambient air. All available capture technologies can be used.

[0068] CO2 is most cost-effective to capture at point sources such as large carbon-based energy facilities, industries with large CO2 emissions (e.g. cement production, steelmaking), natural gas processing, synthetic fuel plants, and fossil fuel-based hydrogen production plants. Extracting CO2 from air is possible, although the lower concentration of CO2 in air compared to combustion sources complicates the engineering and therefore makes the process more expensive.

[0069] In some preferred embodiments, the carbon dioxide provided in step (b) is captured from industrial flue gas.

[0070] In post-combustion capture, CO2 is removed after fossil fuels are burned - this is the approach used for fossil fuel power plants. CO2 is captured from flue gases at power stations or other point sources. Absorption or carbon scrubbing using amines is the main capture technology. It is the only carbon capture technology that has been used industrially to date.

[0071] Based on the porosity and selectivity of the MOF (metal-organic framework), CO2 is adsorbed onto the MOF by physical or chemical adsorption, leaving a gas stream depleted in CO2. The CO2 is then stripped from the MOF using temperature swing adsorption (TSA) or pressure swing adsorption (PSA), so the MOF can be reused.

[0072] In some other preferred embodiments, the carbon dioxide provided in step (b) is captured from ambient air.

[0073] Direct air capture (DAC) is the process of capturing carbon dioxide (CO2) directly from ambient air and producing a concentrated CO2 stream for sequestration or utilization or the production of carbon-neutral fuels. The removal of carbon dioxide is achieved when ambient air is brought into contact with a chemical medium (typically an aqueous alkaline solvent or adsorbent). Subsequently, the CO2 in these chemical media is stripped by applying energy (i.e., heat), producing a CO2 stream that can undergo dehydration and compression, while simultaneously regenerating the chemical medium for reuse.

[0074] Dilute CO2 can be separated efficiently using an anion exchange polymer resin called Marathon MSA, which absorbs CO2 from the air when dry and releases CO2 when exposed to moisture. Most of the energy for the process is supplied by the latent heat of phase change of water. Other materials that can be used are metal organic frameworks (or MOFs). Membrane separation of CO2 relies on semipermeable membranes.

[0075] In step (c), hydrogen and carbon dioxide react in the presence of a catalyst to form methanol.

[0076] Kristian Stangeland, Hailong Li and Zhixin Yu give an overview of suitable catalyst systems in Energy, Ecology and Environment, Volume 5, Pages 272-285 (2020). The process requires a multicomponent catalyst system. The interaction between the components is crucial for the high activity and selectivity of CO2 to methanol catalysts. This has been demonstrated by a variety of catalyst systems composed of various metals (i.e., Cu, Pd, Ni) and metal oxides (i.e., ZnO, ZrO2, In2O3). These complex systems can contain mixtures of metal phases, alloy phases and metal oxide phases. The most promising catalyst systems for large-scale industrial processes are currently Cu-based and In-based catalysts due to their excellent catalytic properties.

[0077] The process for CO2 to methanol synthesis can be carried out, for example, by the process known from DE-A-42 20 865, which produces methanol under the influence of silent electrical discharges.

[0078] Alternatively, the methanol synthesis can also be carried out under pressure and elevated temperature and in the presence of copper-based catalysts in thermal reactors (DE 43 32 789 A1; DE 19739773 A1).

[0079] Typical catalysts are described, for example, by N. Kanoun et al. in the publication "Catalytic properties of Cu based catalysts containing Zr and / or V for methanol synthesis from a carbon dioxide and hydrogen mixture" in CATALYSIS LETTERS 15, (1992) 231-235. Potential catalysts such as CuO / ZnO and Cu-ZnO-Al2O3 are also described by RM Navarro et al. in "Methanol Synthesis from CO2: A Review of the Latest Developments in Heterogeneous Catalysis" Materials (2019), 12, 3902 and "Catalytic carbon dioxide hydrogenation to methanol: A review of recent studies" chemical engineering research and design 92 (2014) 2557-2567.

[0080] Recently, a highly selective catalyst In2O3 / ZrO2 has been described for industrially relevant conditions. Typical industrially relevant conditions for CO2 hydrogenation to methanol are in the range of T = 200°C-300°C, P = 10-50 MPa, and a gas hourly space velocity (GHSV) of 16000-48000 h -1 (Angew. Chem. Int. Ed. [German Angewandte Chemie International Edition] 2016, 55, 6261-6265).

[0081] Step (c) may be carried out in the presence of a copper-zinc-alumina catalyst. If a copper-zinc-alumina catalyst is employed, the preferred temperature is in the range of 150°C to 300°C, preferably 175°C to 300°C, and the preferred pressure is in the range of 10 to 150 bar (abs).

[0082] Typically, ethylene is produced from methanol in a methanol to olefins process (MTO process). Since the process involves the cleavage of C-H bonds and CD bonds, respectively, the associated primary isotope effects will be significant. In the MTO process, a mixture of ethylene and propylene is produced from methanol over a highly selective silica aluminophosphate zeolite catalyst in a fluidized bed operation. The ratio of propylene to ethylene can be adjusted by selecting appropriate process conditions and can vary from 0.77 in ethylene production mode to 1.33 in propylene production mode.

[0083] The overall kinetic isotope effect is cumulative, as it will also be present in all subsequent production steps downstream in the value chain.

[0084] The deuterium content of the hydrogen produced by electrolysis and the deuterium content of the methanol obtained according to the invention can be determined by mass spectrometry. If the hydrogen is produced by electrolysis according to the invention, its deuterium content is below 90 ppm. Thus, it can be determined by the deuterium content of the methanol whether the methanol was produced using hydrogen from water electrolysis or conventionally (e.g. via synthesis gas from natural gas).

[0085] The methanol obtainable according to the invention having a deuterium content of less than 90 ppm based on the total hydrogen content can be used in fuel applications such as the production of MTBE / TAME, gasoline blending, the production of dimethyl ether and the production of biodiesel, for the production of formaldehyde, acetic acid, olefins, sodium methoxide, methylation products such as dimethylphenol, for the production of dimethyl terephthalate and methyl mercaptan.

[0086] The formaldehyde obtained from the methanol of the present invention can be further used, for example, for the production of polyoxymethylene, butanediol, methylene diphenyl diisocyanate, neopentyl glycol, methacrylic acid, phenol formaldehyde resins, urea condensation resins, melamine resins and acetone resins.

[0087] The acetic acid obtained from the methanol of the present invention can be further used, for example, for the production of chloroacetic acid, acetic esters, methyl isopropyl ketone and acetic anhydride.

[0088] The methyl mercaptan obtained from the methanol of the present invention can be further used, for example, for the production of methylmercaptopropionaldehyde, dimethyl disulfide and methanesulfonic acid.

[0089] In particular, the present invention also relates to the use of methanol obtainable by the process according to the invention and having a deuterium content of less than 90 ppm, based on the total hydrogen content, for the production of formaldehyde, acetic acid, methylamine, methyl tert-butyl ether, methyl methacrylate, trimethylolpropane, methyl chloride, methylchlorosilane and silicones.

[0090] The present invention also relates to a method for producing formaldehyde, which comprises steps (a) to (c) as described above and the following additional step:

[0091] (d) dehydrogenating or oxidizing the methanol obtained in step (c) to obtain formaldehyde.

[0092] Formaldehyde is produced industrially by catalytic oxidation of methanol. The most common catalysts are metallic silver, iron (III) oxide, iron molybdenum oxide or vanadium oxide. In the commonly used formox process, methanol and oxygen react in the presence of iron oxide combined with molybdenum and / or vanadium at about 250°C-400°C to produce formaldehyde according to the following chemical equation:

[0093] 2CH3OH+O2→2CH2O+2H2O

[0094] Silver-based catalysts usually operate at higher temperatures (about 650°C). Two chemical reactions simultaneously produce formaldehyde: the above and the following dehydrogenation reaction:

[0095] CH3OH→CH2O+H2

[0096] The formaldehyde obtained in step (d) can be used to produce trimethylolpropane. In another aspect, the present invention also relates to a method for producing trimethylolpropane, which comprises steps (a) to (d) and the following additional steps:

[0097] (e) reacting the formaldehyde obtained in step (d) with butyraldehyde to obtain trimethylolpropane.

[0098] Trimethylolpropane is produced via a two-step process, starting with the condensation of butyraldehyde with formaldehyde:

[0099] CH3CH2CH2CHO+2CH2O→CH3CH2C(CH2OH)2CHO

[0100] The second step requires the Cannizzaro reaction:

[0101] CH3CH2C(CH2OH)2CHO+CH2O+NaOH→

[0102] CH3CH2C(CH2OH)3+NaO2CH

[0103] The present invention also relates to a method for producing acetic acid, comprising steps (a) to (c) as described above and the following additional step:

[0104] (d) reacting the methanol obtained in step (c) with carbon monoxide to obtain acetic acid.

[0105] Acetic acid can be produced by the carbonylation of methanol in step (d). The process involves methyl iodide as an intermediate and is carried out in three steps. The carbonylation (step 2) requires a metal carbonyl catalyst.

[0106] 1.CH3OH+HI→CH3I+H2O

[0107] 2. CH3I+CO→CH3COI

[0108] 3.CH3COI+H2O→CH3COOH+HI

[0109] There are two related processes for the carbonylation of methanol: the rhodium-catalyzed Monsanto process, and the iridium-catalyzed Cativa process.

[0110] The Monsanto process operates at a pressure of 30-60 atm and a temperature of 150°C-200°C and gives a selectivity of greater than 99%. The catalytically active species is the anion cis-[Rh(CO)2I2] - The first organometallic step is the oxidative addition of iodomethane to cis-[Rh(CO)2I2] - To form a hexacoordinated substance [(CH3)Rh(CO)2I3] - This anion is rapidly transformed by migration of the methyl group to the adjacent carbonyl ligand to give the pentacoordinated acetyl complex [(CH3CO)Rh(CO)I3] - The pentacoordinate complex then reacts with carbon monoxide to form a hexacoordinate dicarbonyl complex that undergoes reductive elimination to release acetyl iodide (CH3C(O)I). The catalytic cycle involves two non-organometallic steps: conversion of methanol to methyl iodide and hydrolysis of acetyl iodide to acetic acid and hydrogen iodide.

[0111] The Cativa process is another process for producing acetic acid by carbonylation of methanol. The technology is similar to the Monsanto process. The process is based on an iridium-containing catalyst, such as the complex [Ir(CO)2I2] - The catalytic cycle of the Cativa process begins with the reaction of methyl iodide with a square planar active catalyst species to form an octahedral iridium(III) species [Ir(CO)2(CH3)I3] - The oxidative addition reaction involves the insertion of an iridium (I) central form into the carbon-iodine bond of methyl iodide. After ligand exchange of the iodide with carbon monoxide, the carbon monoxide migrates into the iridium-carbon bond resulting in the formation of a species with a bound acetyl ligand. The active catalyst species is regenerated by elimination of acetyl iodide by reduction. In the process of generating hydroiodic acid, acetyl iodide is hydrolyzed to produce acetic acid product, which in turn is used to convert the starting material methanol into methyl iodide used in the first step.

[0112] The present invention also relates to a method for producing methylamine, which comprises steps (a) to (c) as described above and the following additional step:

[0113] (d) reacting the methanol obtained in step (c) with ammonia to obtain methylamine.

[0114] Step (d) may be carried out at 350° C. to 450° C. and 15 to 25 bar in the presence of a catalyst comprising Al 2 O 3 and SiO 2 .

[0115] The present invention also relates to a method for producing methyl tert-butyl ether, which comprises steps (a) to (c) as described above and the following additional step:

[0116] (d) reacting the methanol obtained in step (c) with isobutylene to obtain methyl tert-butyl ether.

[0117] Step (d) can be carried out at 40 to 90° C. and 3 to 20 bar in the presence of an acidic ion exchanger.

[0118] The present invention also relates to a process for producing methyl methacrylate, comprising steps (a) to (c) as described above and the following additional step:

[0119] (d) reacting the methanol obtained in step (c) with methacrylic acid to obtain methyl methacrylate.

Claims

1. A method for producing methanol having a deuterium content of less than 90 ppm based on the total hydrogen content, the method comprising the steps of: (a) providing hydrogen having a deuterium content of less than 90 ppm based on the total hydrogen content by water electrolysis using electricity generated at least in part from non-fossil renewable resources; (b) providing carbon dioxide; (c) reacting hydrogen and carbon dioxide in the presence of a catalyst to form methanol.

2. The method according to claim 1, wherein: The electricity is generated by wind, solar, biomass, hydro and geothermal energy.

3. The method according to claim 1 or 2, wherein: Hydrogen is provided by water electrolysis using a polymer electrolyte membrane.

4. The method according to claim 3, wherein: Hydrogen is provided by proton exchange membrane water electrolysis (PEMWE) or anion exchange membrane water electrolysis (AEMWE).

5. The method according to any one of claims 1 to 4, wherein: The carbon dioxide provided in step (b) is captured from industrial flue gases.

6. The method according to any one of claims 1 to 4, wherein: The carbon dioxide provided in step (b) is captured from ambient air.

7. The method according to any one of claims 1 to 6, wherein: Step (c) is carried out in the presence of a copper-zinc-alumina catalyst.

8. The method according to any one of claims 1 to 7, wherein: The hydrogen provided in step (a) has a deuterium content of 30 to 75 ppm.

9. The method according to any one of claims 1 to 8, wherein: The carbon dioxide provided in step (b) has a δ corresponding to -10‰ to -2.5‰. 13 C value 13 C content.

10. Methanol having a deuterium content of less than 90 ppm based on the total hydrogen content, obtainable by the process according to any one of claims 1 to 9.

11. Methanol according to claim 10, having a deuterium content of 30 to 75 ppm based on the total hydrogen content.

12. Methanol according to claim 10 or 11, having a δ corresponding to -10‰ to -2.5‰ 13 C value 13 C content.

13. Use of methanol according to any one of claims 10 to 12 for producing ethylene.

14. Use of methanol according to any one of claims 10 to 12 for the production of formaldehyde, acetic acid, methylamine, methyl tert-butyl ether, methyl methacrylate, trimethylolpropane, methyl chloride, methylchlorosilane and silicone.

15. A process for producing formaldehyde, comprising steps (a) to (c) as defined in any one of claims 1 to 9 and the following additional step: (d) dehydrogenating or oxidizing the methanol obtained in step (c) to obtain formaldehyde.

16. A process for producing trimethylolpropane, comprising steps (a) to (d) as defined in claim 15 and the following additional step: (e) reacting the formaldehyde obtained in step (d) with butyraldehyde to obtain trimethylolpropane.

17. A process for producing acetic acid, the process comprising steps (a) to (c) as defined in any one of claims 1 to 9 and the following additional step: (d) reacting the methanol obtained in step (c) with carbon monoxide to obtain acetic acid.

18. A process for producing methylamine, comprising steps (a) to (c) as defined in any one of claims 1 to 9 and the following additional step: (d) reacting the methanol obtained in step (c) with ammonia to obtain methylamine.

19. The method according to claim 18, wherein: Step (d) is carried out at 350° C. to 450° C. and 15 to 25 bar in the presence of a catalyst comprising Al 2 O 3 and SiO 2 .

20. A process for producing methyl tert-butyl ether, comprising steps (a) to (c) as defined in any one of claims 1 to 9 and the following additional step: (d) reacting the methanol obtained in step (c) with isobutylene to obtain methyl tert-butyl ether.

21. The method according to claim 20, wherein: Step (d) is carried out at 40 to 90° C. and 3 to 20 bar in the presence of an acidic ion exchanger.

22. A process for producing methyl methacrylate, comprising steps (a) to (c) as defined in any one of claims 1 to 9 and the following additional step: (d) reacting the methanol obtained in step (c) with methacrylic acid to obtain methyl methacrylate.