New coolant compositions

Abstract

The present invention relates to new coolant compositions for cooling systems, which compositions are based on renewable raw materials.

Description

[0001] New coolant compositions

[0002] Description

[0003] The present invention describes novel coolant compositions for cooling systems based on renewable raw materials.

[0004] Coolants for use in mobile or stationary combustion engines, but also in cooling circuits of electric vehicles or combinations of vehicles with electric and combustion engines, are generally liquid mixtures of water, glycols, corrosion inhibitors and other components.

[0005] The freezing point-depressing glycol component is usually monoethylene glycol and / or monopropylene glycol, predominantly monoethylene glycol.

[0006] Industrially, monoethylene glycol is usually produced by opening ethylene oxide with water, whereby the ethylene oxide is produced from ethylene, which in turn is obtained by cracking fossil naphtha in steamer fields.

[0007] This production method has at least the following disadvantages:

[0008] - Fossil raw materials are a finite resource

[0009] - The use of fossil raw materials increases the carbon footprint and leads to a poor ecological balance of the resulting products

[0010] - Ethylene oxide (oxirane) as a carcinogenic substance can only be manufactured and handled under strict safety measures due to its high toxicity and safety properties (flash point, ignition temperature, explosion limits)

[0011] - The reaction of ethylene oxide with water produces not only the desired monoethylene glycol, but also, in varying proportions, the higher oligomers, especially diethylene glycol, triethylene glycol, etc.

[0012] These higher oligomers must be laboriously separated from the monoethylene glycol, usually by distillation, but they remain in the monoethylene glycol in small amounts. The presence of higher oligomers results in a non-uniform boiling point of the product. Higher alkylene glycols often act as emulsifiers or foaming agents, so that a high proportion of higher alkylene glycols causes foaming when mixed with water in the end user.

[0013] Due to the high boiling point of monoethylene glycol of approximately 197 °C at ambient pressure, the distillative separation from the higher oligomers requires a great deal of energy through the addition of heat and the creation of a vacuum, and the separation from the higher oligomers is not complete. In practice, monopropylene glycol (1,2-propylene glycol) is used less frequently instead of monoethylene glycol as a freezing-point-depressant. However, the problem is essentially the same, since 1,2-propylene glycol is produced analogously from propylene oxide, which in turn is produced from propene, which is also derived from naphtha.

[0014] The object of the present invention was to provide coolants that reduce the above disadvantages, in particular the high carbon footprint.

[0015] The object was achieved by coolants which contain monoethylene glycol and / or monopropylene glycol as freezing point lowering glycol component, preferably monoethylene glycol which has been obtained at least partially from renewable raw materials.

[0016] The production of glycols, especially monoethylene glycol, from renewable raw materials is well known. As a C2 substance, monoethylene glycol is available in a variety of ways, for example:

[0017] - From Ci compounds by C2 construction and CC linkage

[0018] - From C2 compounds, mostly by oxidation or reduction

[0019] - From compounds with at least 3 carbon atoms by degradation and / or cleavage of the carbon skeleton

[0020] These manufacturing variants are briefly described below:

[0021] From Ci compounds

[0022] The production of ethylene glycol from Ci compounds can preferably be carried out from a CO2- and / or CO-containing gas or gas mixture in the presence of reducing equivalents, for example hydrogen, particularly preferably in a biological process.

[0023] A preferred process is described in WO 2019 / 126400 A1. In this process, a gas mixture containing hydrogen (H2) and carbon dioxide (CO2) and / or carbon monoxide (CO) is converted by genetically modified microorganisms into monoethylene glycol or possible precursors of monoethylene glycol (see below for C2 compounds).

[0024] The genetic modification may involve the development of foreign, heterologous enzymes for the conversion of oxaloacetate to citrate, the conversion of glycine to glyoxylate, the conversion of isocitrate to glyoxylate, and the conversion of glycolate to glycoaldehyde. These enzymes may be the following:

[0025] For the conversion of oxaloacetate to citrate: citrate [Si]-synthase [2.3.3.1], ATP citrate synthase [2.3.3.8]; or citrate (Re)-synthase [2.3.3.3],

[0026] For the conversion of glycine into glyoxylate alanine-glyoxylate transaminase [2.6.1.44], serineglyoxylate transaminase [2.6.1.45], serine-pyruvate transaminase [2.6.1.51 ], glycineoxaloacetate transaminase [2.6.1.35], glycine transaminase [2.6.1.4], glycine dehydrogenase [1.4.1.10], alanine dehydrogenase [1.4.1.1], or glycine dehydrogenase [1.4.2.1],

[0027] For the conversion of isocitrate to glyoxylate isocitrate lyase [ 4.1.3 .1],

[0028] For the conversion of glycolates into glycoaldehyde glycolaldehyde dehydrogenase [1.2.1.21], lactaldehyde dehydrogenase [1.2.1.22], succinate-semialdehyde dehydrogenase [1.2.1.24], 2,5-dioxovalerate dehydrogenase [1.2.1.26], aldehyde dehydrogenase [1.2.1.3 / 4 / 5], betaine-aldehyde dehydrogenase [1.2.1.8] or aldehyde ferredoxin oxidoreductase [1.2.7.5],

[0029] Such enzymes can be obtained from microorganisms selected from the group consisting of the genera Bacillus, Clostridium, Escherichia, Gluconobacter, Hyphomicrobium, Lysinibacillus, Paenibacillus, Pseudomonas, Sedimenticola, Sporosarcina, Streptomyces, Thermithiobacillus, Thermotoga, and Zea.

[0030] Also possible are microorganisms containing enzymes selected from the group consisting of isocitrate dehydrogenase, glycerate dehydrogenase, glycolate dehydrogenase, glycerate dehydrogenase, glycolate dehydrogenase, aldehyde ferredoxin oxidoreductase and aldehyde dehydrogenase.

[0031] In a preferred embodiment, the microorganisms are selected from the group consisting of Acetobacterium, Alkalibaculum, Blautia, Butyribacterium, Clostridium, Eubacterium, Moorella, Oxobacter, Sporomusa and Thermoanaerobacter. They are very particularly preferably selected from the group consisting of Acetobacterium woodii, Alkalibaculum bacchii, Blautia producta, Butyribacterium methylotrophicum, Clostridium aceticum, Clostridium autoethanogenum, Clostridium carboxidivorans, Clostridium coskatii, Clostridium drakei, Clostridium formicoaceticum, Clostridium ljungdahlii, Clostridium magnum, Clostridium ragsdalei, Clostridium scatologenes, Eubacterium limosum, Moorella thermautotrophica, Moorella thermoacetica, Oxobacter pfennigii, Sporomusa ovata, Sporomusa silvacetica, Sporomusa sphaeroides, and Thermoanaerobacter kiuvi, in particular selected from the group consisting of Clostridium autoethanogenum, Clostridium ljungdahlii and Clostridium ragsdalei

[0032] The above-mentioned enzymes or nucleic acids encoding them are preferably expressed in microorganisms selected from the group consisting of the genera Bacillus, Clostridium, Escherichia, Gluconobacter, Hyphomicrobium, Lysinibacillus, Paenibacillus, Pseudomonas, Sedimenticola, Sporosarcina, Streptomyces, Thermithiobacillus, Thermotoga, Zea, Klebsiella, Mycobacterium, Salmonella, Mycobacteroides, Staphylococcus, Burkholderia, Listeria, Acinetobacter, Shigella, Neisseria, Bordetella, Streptococcus, Enterobacter, Vibrio, Legionella, Xanthomonas, Serratia, Cronobacter, Cupriavidus, Helicobacter, Yersinia, Cutibacterium, Francisella, Pectobacterium, Arcobacter, Lactobacillus, Shewanella, Erwinia, Sulf urospirillum, Peptococcaceae, Thermococcus, Saccharomyces, Pyrococcus, Glycine, Homo, Ralstonia, Brevibacterium, Methylobacterium, Geobacillus, bos, gallus, Anaerococcus, Xenopus, Amblyrhynchus, rattus, mus, sus, Rhodococcus, Rhizobium, Afegasphaera, Mesorhizobium, Peptococcus,Agrobacterium, Campylobacter, Acetobacterium, Alkalibaculum, Blautia, Butyribacterium, Eubacterium, Moorella, Oxobacter, Sporomusa, Thermoanaerobacter, Schizosaccharomyces, Paenibacillus, Fictibacillus, Lysinibacillus, Ornithinibacillus, Halobacillus, Kurthia, Lentibacillus, Anoxybacillus, Solibacillus, Virgibacillus, Alicyclobacillus, Spo- rosarcina, Salimicrobium, Sporosarcina, Pianococcus, Corynebacterium, Thermaerobacter, Sulfobacillus und Symbi- obacterium,

[0033] Preferably, genetically modified microorganisms selected from the group consisting of Clostridium acetobutylicum, Clostridium beijerinckii, Escherichia coli, Saccharomyces cerevisiae, Acetobacterium woodii, Alkalibaculum bacchii, Blautia product, Butyribacterium methylotrophicum, Clostridium aceticum, Clostridium autoethanogenum, Clostridium carboxidivorans, Clostridium coskatii, Clostridium drakei, Clostridium formicoaceticum, Clostridium ljungdahlii, Clostridium magnum, Clostridium ragsdalei, Clostridium scatologenes, Eubacterium limosum, Moorella thermautotrophica, Moorella thermoacetica, Oxobacter pfennigii, Sporomusa ovata, Sporomusa silvacetica, Sporomusa sphaeroides and Thermoanaerobacter kiuvi, particularly preferably selected from the group consisting of Clostridium autoethanogenum, Clostridium ljungdahlii, and Clostridium ragsdalei, in particular Clostridium autoethanogenum LZ1561,as described in WO 2012 / 015317.,

[0034] The carbon dioxide (CO2) and / or carbon monoxide (CO) used can come from any source, for example from exhaust gases, combustion gases, fermentation gases, synthesis gas or from capture from the air (also known as carbon capture (CO) or carbon capture and utilisation (CCU)).

[0035] A carbon footprint advantage arises when the carbon dioxide (CO2) and / or carbon monoxide (CO) used in the process is not produced specifically for the process from fossil sources. However, the use of carbon dioxide (CO2) and / or carbon monoxide (CO) from exhaust gases or combustion gases, which would otherwise be released into the atmosphere without their use in this process, is advantageous.

[0036] The carbon dioxide (CO2) and / or carbon monoxide (CO) used in the process preferably comes from renewable raw materials, for example from combustion processes or fermentation.

[0037] It is also advantageous if the carbon dioxide (CO2) used is captured from the air and used in the process (carbon capture and utilization (CCU)). In this case, the monoethylene glycol obtained from the process represents a carbon sink.

[0038] The product mixture obtained from this process can contain not only monoethylene glycol but also its biosynthetic precursors, such as glycolic acid, glyoxylic acid, and / or glycolaldehyde. To convert these precursors into the desired product, monoethylene glycol, the reaction mixture can therefore preferably be subjected to hydrogenation. The reaction mixture is usually obtained as an aqueous solution, from which monoethylene glycol can be separated, preferably by distillation, rectification, or stripping (collected here for simplicity under the term distillation). Since the byproducts of the reaction tend to be low-boiling, the energy required for distillation is lower than that required for separating monoethylene glycol from higher oligomers in the reaction of ethylene oxide with water.

[0039] Furthermore, the separation of monoethylene glycol can also be achieved using non-distillation methods, such as membrane filtration or reverse osmosis. A combination of distillation and non-distillation methods is also conceivable.

[0040] An example of a process for the production of monoethylene glycol precursors starting from a Ci source other than CO or CO2 is the production of oxalic acid or its salts from formic acid or its salts. This is usually done in the form of an alkali metal formate, for example, sodium or potassium formate, by reaction with a strong base, such as metal hydrides or alkali metal hydroxides, especially sodium hydroxide. However, this process is less preferred.

[0041] Glycolaldehyde can also be produced by reacting formaldehyde with carbon monoxide and hydrogen in a hydroformylation reaction. The resulting glycolaldehyde is then hydrogenated to monoethylene glycol, as described in US 4496781 B1.

[0042] In a further embodiment, CO2 and / or CO can be hydrogenated with hydrogen to methanol, this methanol can be converted to ethene in a methanol to olefin (MTO) process, ethene can be oxidized to ethylene oxide and then ethylene oxide can be converted with water to monoethylene glycol.

[0043] The production of methanol by hydrogenation of carbon oxides, especially carbon dioxide, is well known:

[0044] An overview of suitable catalyst systems is provided by Kristian Stangeland, Hailong Li, and Zhixin Yu, Energy, Ecology and Environment, Volume 5, pages 272–285 (2020). Multicomponent catalyst systems are required for this process. The interaction between the components is crucial for high activity and selectivity of CO2-to-methanol catalysts. This has been demonstrated for numerous catalyst systems consisting of various metals (e.g., Cu, Pd, Ni) and metal oxides (e.g., ZnO, ZrO2, I^Oa). These complex systems can contain a mixture of metal, alloy, and metal oxide phases. Currently, the most promising catalyst systems for large-scale processes are Cu- and In-based catalysts due to their superior catalytic performance.

[0045] A process for CO2-to-methanol synthesis can be carried out, for example, using the method known from DE-A-42 20 865, in which methanol is produced under the influence of silent electrical discharges. Alternatively and preferably, the methanol synthesis can also be carried out in a thermal reactor under pressure and elevated temperature and in the presence of a copper-based catalyst (DE 43 32 789 A1; DE 19739773 A1).

[0046] Typical catalysts are described, for example, in the publication by N. Kanoun et al., "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-AfeOs are also described by R.M. Navarro et al., "Methanol Synthesis from CO2: A Review of the Latest Developments in Heterogeneous Catalysis," Materials (2019), 12, 3902, and in "Catalytic carbon dioxide hydrogenation to methanol: A review of recent studies" in Chemical Engineering Research and Design 92 (2014) 2557-2567.

[0047] Recently, a highly selective catalyst, ln2O3 / ZrO2, was described for industrially relevant conditions. Typical industrially relevant conditions for the hydrogenation of CO2 to methanol are T=200–300°C, p=10–50 MPa, and a gas hourly space velocity (GHSV) of 16,000–48,000 h 1(Angew. Chem. Int. Ed. 2016, 55, 6261 - 6265).

[0048] This step can be carried out in the presence of a copper-zinc-alumina catalyst. When copper-zinc-alumina catalysts are used, the preferred temperature is in the range of 150 to 300 °C, preferably 175 to 300 °C, and the preferred pressure is in the range of 10 to 150 bar (abs).

[0049] The conversion of methanol via ethene to ethylene oxide is described, for example, in US 2002 / 132864 A1; the subsequent conversion of ethylene oxide with water to monoethylene glycol is an industrial standard.

[0050] In a preferred embodiment, hydrogen obtained not from fossil sources but from the electrolysis of water is used for this hydrogenation. The electrical current for the electrolysis is particularly preferably sourced from renewable energy sources. Hydrogen obtained by the electrolysis of water is characterized by a deuterium content below the natural level, preferably below 90 ppm. This low deuterium content is then found in the corresponding subsequent products. Such a process for the production of methanol from CO2 is described in WO 2023 / 213583; the production of monoethylene glycol is described in the unpublished European patent application with the file number 23206933.6 and the filing date of October 31, 2023.According to this latter application, particularly preferred monoethylene glycol has a deuterium content of no more than 117, preferably no more than 115, more preferably no more than 113, and most preferably no more than 110 ppm. From C2 compounds.

[0051] In this production variant, an existing C2 carbon skeleton is usually modified by oxidation or reduction, whereby the underlying C2 body originates at least partially, preferably entirely, from natural sources or has been obtained from renewable raw materials.

[0052] For example, the production of monoethylene glycol by reducing glycolic acid (HO-CH2-COOH), glyoxylic acid (OHC-COOH), oxalic acid (HOOC-COOH), glyoxal (OHC-CHO), and / or glycolaldehyde (HO-CH2-CHO), or mixtures thereof, derived from natural sources or from renewable raw materials, is conceivable. These compounds, individually or in any mixture, are referred to herein as "precursors" of monoethylene glycol.

[0053] The reduction can be achieved biochemically or by conventional chemical hydrogenation. Electrochemical reduction to monoethylene glycol is also conceivable.

[0054] The use of ethanol, acetaldehyde, or acetic acid, or mixtures thereof, derived from natural sources or renewable raw materials, is also welcome. These are first oxidized to one of the above components and then reduced. The oxidation can be carried out biochemically or by conventional chemical means.

[0055] In a particular embodiment, ethylene or propene can be produced partially or entirely from renewable raw materials. This can be achieved, for example, by partially or completely replacing or supplementing naphtha with a renewable raw material in a steam cracker or other cracking process. The resulting ethylene or propene is then converted in a conventional manner to ethylene oxide or propylene oxide, respectively, and subsequently to monoethylene glycol or monopropylene glycol, respectively.

[0056] In one embodiment, the renewable raw material is biogas, i.e., a gas mixture produced by the fermentation of biomass, which predominantly contains methane as a hydrocarbon. Other components of biogas are typically carbon dioxide (CO2), and often also nitrogen (N2), oxygen (O2), hydrogen sulfide (H2S), hydrogen (H2), and / or ammonia (NH3). However, these other components are preferably separated before utilization.

[0057] Biomass used for fermentation can include:

[0058] - fermentable, biomass-containing residues such as sewage sludge, organic waste or food waste,

[0059] - farmyard manure (liquid manure, dung),

[0060] - plants or parts of plants not used for any other purpose (catch crops or plant residues) and

[0061] - Purposefully cultivated energy crops. Examples include silage from corn, grass, rye, and sugar beets, fodder beets, organic waste, sugar cane, and manure or slurry from chicken, pig, and cattle farming.

[0062] In a further preferred embodiment, fats and oils are preferred as renewable raw materials for this case, particularly preferably triglycerides containing stearic acid, palmitic acid, lauric acid, oleic acid, linoleic acid and / or linolenic acid.

[0063] Particularly preferred are industrially common fats and oils such as tallow, coconut oil, cod liver oil, coconut palm kernel oil, rapeseed oil, soybean oil, rapeseed oil, peanut oil, macauba oil and palm oil, which contain oleic acid and palmitic acid as main components.

[0064] Also conceivable as substrates are fatty acids obtained by saponification of fats and oils, for example, stearic acid, palmitic acid, lauric acid, oleic acid, linoleic acid, and / or linolenic acid. Industrially common fatty acid mixtures are preferably tallow fatty acid, coconut oil fatty acid, cod liver oil fatty acid, coconut palm kernel oil fatty acid, soybean oil fatty acid, rapeseed oil fatty acid, peanut oil fatty acid, or palm oil fatty acid, which contain oleic acid and palmitic acid as their main components.

[0065] When using an oil obtained from palm trees, in a particular embodiment the oil is extracted from a palm tree, preferably a palm tree of the genus Acrocomia, particularly preferably a Macaüba palm, and in particular Acrocomia aculeata, and the oil is extracted from the palm fruit pulp and / or the palm kernel, wherein the plant is preferably a Macaüba palm and the oil is extracted from the Macaüba kernel, and in particular wherein the plant is Acrocomia aculeata and the oil is extracted from the Acrocomia aculeata kernel.

[0066] The term "Macaüba palm," as used here, refers to a palm species. Examples include "Acrocomia aculeata" (also known as "Macaiba," "Boicaiuva," "Macaüva," "Coco-de-Catarro," "Coco-Baboso," and "Coco-de-Espinho"), "Acrocomia hassleri," and "Acrocomia totei." Macaüba palms, for example, can grow up to about 15 meters tall. The Macaüba fruit consists of pulp and a kernel. The term "pulp," as used here, refers to the inner pulp. The term "kernel," as used here, is interchangeable with "seed" or "almond kernel."

[0067] The Macauba palm has a high oil yield in tons per hectare per year. The term "oil yield in tons per hectare per year," as used here, refers to the oil obtained from the plant's fruit, for example, by extraction, where the fruit includes the pulp and kernel. It refers to the oil produced per hectare. It is understood that this value refers to the oil yield obtained from a monoculture, with the plants cultivated under standard conditions that depend on the specific plant and are known to the person skilled in the art. Therefore, if the plant is not grown in a monoculture (e.g., on a pasture), the respective value for that specific crop may be reduced.Typically, oil palm has an oil yield in tonnes per hectare per year of about 3.8 t / ha / year, rapeseed has an oil yield in tonnes per hectare per year of about 0.8 t / ha / year, sunflower has an oil yield in tonnes per hectare per year of about 0.7 t / ha / year and soy has an oil yield in tonnes per hectare per year of about 0.6 t / ha / year.

[0068] The term "monoculture," as used here, refers to the practice of cultivating one plant at a time, such as the Macauba palm, in a field. Using the Macauba palm as an example, approximately 500 to 600 palm trees can be planted per hectare. It is preferable that the minimum distance between trees be approximately 3.5 to 4.5 meters. This number varies depending on the soil, for example.

[0069] While this process does not mitigate the disadvantages resulting from the handling of ethylene oxide and / or ethylene glycols, it does reduce the carbon footprint by partially or completely replacing fossil fuels with renewable raw material sources. One advantage of this production variant is that existing production facilities for ethylene oxide or ethylene glycols require essentially no modification, allowing the established and optimized processes to continue operating largely unchanged when ethylene based on renewable raw materials becomes available.

[0070] From C>3 compounds

[0071] In a preferred embodiment, monoethylene glycol and / or monopropylene glycol, preferably monoethylene glycol, is obtained from at least three carbon atoms, optionally repeating organic compounds of a renewable raw material. These compounds preferably have 3 to 20, preferably 4 to 18, particularly preferably 5 to 16, most particularly preferably 6 to 14, and especially 6 carbon atoms. These compounds can be present, for example, in monomeric form or in the form of a biopolymer.

[0072] The compounds can be of plant or animal origin, preferably plant.

[0073] Carbohydrate substrates are preferred, with particular preference given to sugars in the monomeric form, and to starch, fibers, lignin, cellulose, and hemicellulose in the biopolymeric form. Sugars are preferably selected from the group consisting of arabinose, fructose, galactose, glucose, lactose, mannose, maltose, sucrose, and xylose. The carbohydrates can preferably be biopolymers based on one or more of these sugars.

[0074] Also conceivable as substrates, although less preferred, are fats and oils, for example triglycerides containing stearic acid, palmitic acid, lauric acid, oleic acid, linoleic acid and / or linolenic acid.

[0075] Technically common fats and oils are tallow, coconut oil, cod liver oil, coconut palm kernel oil, rapeseed oil, soybean oil, rapeseed oil, peanut oil and palm oil, which contain oleic acid and palmitic acid as main components

[0076] Also conceivable as substrates are fatty acids obtained by saponification of fats and oils, for example, stearic acid, palmitic acid, lauric acid, oleic acid, linoleic acid, and / or linolenic acid. Industrially common fatty acid mixtures are preferably tallow fatty acid, coconut oil fatty acid, cod liver oil fatty acid, coconut palm kernel oil fatty acid, soybean oil fatty acid, rapeseed oil fatty acid, peanut oil fatty acid, or palm oil fatty acid, which contain oleic acid and palmitic acid as their main components.

[0077] In a preferred embodiment, monoethylene glycol is obtained from carbohydrate substrates. Monoethylene glycol can be obtained from the main product from the conversion of the carbohydrate substrates, as a byproduct, or in the form of its precursors, from which the monoethylene glycol can then be produced, preferably by hydrogenation.

[0078] The conversion of carbohydrate substrates can preferably involve the following reactions:

[0079] - Hydrolysis

[0080] - Fermentation

[0081] - Pyrolysis

[0082] - Hydrogenolysis

[0083] hydrolysis

[0084] For this purpose, the carbohydrate substrate is reacted in one or more stages with water and optionally additionally with at least one acid and / or at least one enzyme (see below under "Fermentation").

[0085] Biopolymers such as cellulose, hemicellulose, or lignin are often cleaved into oligomeric or monomeric sugars using water and optionally at least one acid at high temperatures. These are then subsequently cleaved into monoethylene glycol and / or its precursors using water and optionally at least one acid or at least one enzyme.

[0086] Precursors can be glycolic acid (HO-CH2-COOH), glyoxylic acid (OHC-COOH), oxalic acid (HOOC-COOH), glyoxal (OHC-CHO) and / or glycolaldehyde (HO-CH2-CHO) or mixtures thereof.

[0087] fermentation

[0088] During fermentation, the carbohydrate substrate is incubated in the presence of at least one microorganism or at least one enzyme and monoethylene glycol and / or its precursors (see above) are obtained.

[0089] This may require prior pretreatment of the carbohydrate substrate, for example, by acidic and / or alkaline cleavage or hydrolysis at high temperatures. This is particularly useful for polymeric carbohydrate substrates to cleave them into oligomeric or monomeric carbohydrates. For acidic cleavage, the carbohydrate substrate is treated with at least one acid, preferably hydrochloric acid, phosphoric acid, sulfuric acid, sulfurous acid, carbonic acid, formic acid, acetic acid, citric acid, tartaric acid, glucuronic acid, galacturonic acid, or succinic acid. Their precursors, such as hydrogen chloride, phosphorus oxide, disulfuric acid, sulfur dioxide, sulfur trioxide, or carbon dioxide, are also conceivable.

[0090] The temperature of the acid treatment is from 100 to 270 °C, preferably 120 to 230, particularly preferably 130 to 200 °C for a duration of 1 to 300 minutes, preferably 30 to 250 and particularly preferably 60 to 150 minutes.

[0091] For alkaline cleavage, the carbohydrate substrate is treated with at least one base, preferably calcium hydroxide (Ca(OH)2), calcium oxide (CaO), ammonia, sodium hydroxide (NaOH), sodium carbonate (Na2CO3), sodium bicarbonate (NaHCOa), potassium hydroxide (KOH), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3) or mixtures thereof.

[0092] The temperature of the alkaline treatment is from 50 to 150 °C, preferably 70 to 120, particularly preferably 80 to 100 °C for a duration of 1 to 300 minutes, preferably 30 to 250 and particularly preferably 60 to 150 minutes.

[0093] Carbohydrate substrates are preferred, with sugars being particularly preferred in the monomeric form, and starch, fibers, lignin, cellulose, and hemicellulose being particularly preferred in the biopolymeric form. Sugars are preferably selected from the group consisting of arabinose, fructose, galactose, glucose, lactose, mannose, maltose, sucrose, and xylose. The carbohydrates can preferably be biopolymers based on one or more of these sugars, with starch, lignin, cellulose, and hemicellulose being preferred.

[0094] The microorganism can be bacteria, fungi or yeast, which may be genetically modified.

[0095] Als Bakterien bevorzugt sind solche der Gattung Thermoanaerobacterium, Thermoanaerobacter, Clostridium, Geobacillus, Saccharococcus, Paenibacillus, Bacillus oder Anoxybacillus, besonders bevorzugt ausgewählt aus der Gruppe bestehend aus Thermoanaerobacterium thermosulfurigenes, Thermoanaerobacterium aotearoense, Thermoanaerobacterium polysaccharolyticum, Thermoanaerobacterium zeae, Thermoanaerobacterium xylanolyticum, Thermoanaerobacterium saccharolyticum, Thermoanaerobium brockii, Thermoanaerobacterium thermosaccharolyti- cum, Thermoanaerobacter thermohydrosulfuricus, Thermoanaerobacter ethanolicus, Thermoanaerobacter brocki, Clostridium thermocellum, Geobacillus thermoglucosidasius, Geobacillus stearothermophilus, Saccharococcus cal- doxylosilyticus, Saccharoccus thermophilics, Paenibacillus campinasensis, Bacillus flavothermus, Anoxybacillus kamchatkensis undAnoxybacillus gonensis.As fungi, those are preferably selected from the group consisting of Chytridiomycota, Blastocladiomycota, Neocallimastigomycota, Zygomycota, Glomeromycota, Ascomycota, Basidiomycota, and T. reesei Rut 30.

[0096] Preferred yeasts are those selected from the group consisting of Ascomycota, Basidiomycota and Saccharomycetales.

[0097] Enzymes used for hydrolyzing a carbohydrate substrate, preferably a carbohydrate substrate previously cleaved under acid and / or basic conditions, are preferably cellulolytic enzymes or cellulases, particularly preferably endoglucanases, cellobiohydrolases, or beta-glucosidases; polypeptides with a cellulolytic enzyme-enhancing effect, particularly preferably GH61 polypeptides; hemicellulolytic enzymes or hemicellulase; xylanase, beta-xylosidase, acetylxylan esterase, feruloyl esterase, alpha-glucuronidase, or alpha-L-arabinofuranosidase. These enzymes and the fermentation conditions are known, for example, from WO 2012 / 075963 or WO 2015 / 17869.

[0098] The fermentation preferably takes place at a temperature of 20 to 60°C, particularly preferably 25 to 50°C, most preferably 32 to 50°C. The pH during fermentation is preferably 3 to 7, particularly preferably 4 to 6, and most preferably 4 to 5.

[0099] Monoethylene glycol and / or its precursors are often obtained as a by-product, for example in the fermentative production of ethanol from carbohydrate substrates, from which they can be separated by distillation or non-distillation methods.

[0100] Traditionally, glucose is fermented to ethanol, from which ethylene can be obtained by dehydration, which can be used as a bio-based ethylene in the conventional production process for monoethylene glycol via ethylene oxide. The disadvantage of this approach is that the fermentation of glucose to ethanol produces 2 mol of CO2 per mol of glucose, so this approach only has an atom economy of 67%.

[0101] Pyrolysis

[0102] In a pyrolysis process, a sugar, preferably a mono- or disaccharide, particularly preferably a monosaccharide, particularly preferably a monomeric hexose, is heated to a high temperature and thermally cleaved. The reaction mixture obtained from the pyrolysis consists predominantly of monoethylene glycol precursors and C1, C3, and / or C4 bodies as byproducts.

[0103] Preferred monosaccharides are arabinose, fructose, galactose, glucose, lactose, mannose, maltose, sucrose, and xylose; glucose is particularly preferred. The sugar can be pyrolyzed in aqueous or alcoholic solution, preferably in aqueous alcoholic solution and particularly preferably in aqueous solution. Methanol, ethanol, ethylene glycol, or propylene glycol, or mixtures thereof, can be used as alcohols.

[0104] One process for pyrolysis is described, for example, in WO 2002 / 40436 A1. In this process, an aqueous solution of a sugar, preferably glucose, is subjected to thermolysis as a fine mist at 500 - 600 °C, preferably 520 - 560 °C, with a residence time of 0.1 - 5, preferably 0.5 - 2 seconds. The resulting reaction mixture is condensed and contains glycolaldehyde as the main product. The C1, C2, C3 and / or C4 bodies formed as by-products are predominantly so-called oxygenates, i.e. C1, C2, C3 and / or C4 bodies with different oxidation states at the respective carbon atoms. These C1, C2, C3 and / or C4 bodies generally contain hydroxyl, aldehyde, keto and / or carboxylic acid groups. Common byproducts are formaldehyde, glyoxal, acetol, pyruvaldehyde.

[0105] For reasons of stability of the glycolaldehyde, it may be useful to first oxidize the glycolaldehyde in the presence of oxygen and metals, preferably noble metals, particularly preferably palladium or platinum, to glycolic acid and then to hydrogenate the reaction mixture thus obtained.

[0106] The resulting reaction mixture is then hydrogenated to a monoethylene glycol-containing product mixture and purified by distillation and / or non-distillation.

[0107] The hydrogenation can be carried out in the presence of hydrogen at a hydrogen pressure of 30 to 150 bar, preferably 40 to 140 and particularly preferably 50 to 120 bar at a temperature of 40 to 160 °C, preferably 50 to 150, particularly preferably 60 to 130 and very particularly preferably 80 to 120 °C.

[0108] Supported copper, cobalt, ruthenium, palladium, platinum, or nickel are typically used as hydrogenation catalysts. Suitable supports include carbon, aluminum oxides, silicates, titanium dioxide, zinc oxide, zirconium, or mixtures thereof; activated carbon is preferred. Copper, cobalt, and nickel can also be used in the form of Raney copper, Raney cobalt, or Raney nickel, respectively.

[0109] Hydrogenation can take place in gas or liquid phase, preferably in liquid phase.

[0110] It is also possible, although less preferred, to first purify the pyrolysis reaction mixture and then hydrogenate it.

[0111] Hydrogenolysis: In one embodiment of hydrogenolysis, glucose is reduced to sorbitol and then converted into ethylene glycol by hydrogenolysis. Exemplary processes are described in US 6297409 B1 or US 2008 / 0228014 A1. Propylene glycol and butanediols are usually formed as byproducts. However, their presence in monoethylene glycol is acceptable for coolants within certain limits due to their freezing-point-lowering effect (see below).

[0112] In another embodiment, a carbohydrate substrate is reacted in a reactor under hydrogen with a tungsten compound and a metal capable of hydrogenolysis from groups 8, 9, or 10 of the Periodic Table of Elements. Such a process is preferably carried out as described in WO 2016 / 114661 A1.

[0113] Possible carbohydrate substrates include poly-, oligo-, di-, and / or monosaccharides of arabinose, fructose, galactose, glucose, lactose, mannose, maltose, sucrose, and / or xylose. Possible sources include starch, fiber, lignin, cellulose, hemicellulose, and sugar.

[0114] The tungsten compound preferably has an oxidation state of at least +2, more preferably an oxidation state of +5 or +6. The tungsten compound is then suitably selected from the group consisting of tungstic acid (H2WO4), ammonium tungstate, ammonium metatungstate, ammonium paratungstate, tungstate compounds comprising at least one element of group 1 or 2, metatungstate compounds comprising at least one element of group 1 or 2, paratungsten compounds comprising at least one element of group 1 or 2, tungsten oxide (WO3), heteropolycompounds of tungsten and combinations thereof.

[0115] The metals capable of hydrogenolysis from groups 8, 9 or 10 of the Periodic Table of the Elements are preferably selected from the group consisting of Cu, Fe, Ni, Co, Pt, Pd, Ru, Rh, Ir, Os and combinations thereof.

[0116] Preferably, the hydrogenolysis metal is selected from the noble metals Pd, Pt, Ru, Rh, Ir, and combinations thereof. These metals have been found to provide good yields. The metal may suitably be present in its metallic form or as its hydride or oxide. It is expected that the metal oxide will be reduced in the presence of hydrogen during the reaction.

[0117] The metal is usually applied to a carrier; suitable carriers include carbon, aluminum oxides, silicates, titanium dioxide, zinc oxide, zirconium or mixtures thereof.

[0118] The reaction takes place, for example, at a temperature of 120 to 280 °C, preferably 140 to 270 °C, particularly preferably 150 to 250 °C, and most preferably 160 to 200 °C, at a hydrogen pressure of 1 to 16 MPa, preferably 2 to 12 MPa, and particularly preferably 3 to 10 MPa. The residence time is generally 5 minutes to 6 hours, preferably 5 minutes to 2 hours. Bio-based monoethylene glycol

[0119] The monoethylene glycol obtained from renewable raw materials, preferably obtainable by one of the methods described above, can be characterized in that the 14 C / 12 C isotope ratio is determined, preferably according to ASTM D 6866 ("Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis").

[0120] According to this test method, the 14 C / 12 C isotope ratio of a sample measured and compared with the 14 C / 12C isotope ratio in a standardized 100% bio-based material. The result is the bio-based content in the sample.

[0121] The application of ASTM-D6866 to derive the "biobased content" is based on the same concepts as radiocarbon dating, but without the use of age equations. The analysis is performed by determining a ratio of the amount of radiocarbon ( 14 C) is determined in an unknown sample compared to that of a modern reference standard. This value is expressed as a percentage using the unit "pMC" (percent modern carbon). If the material being analyzed is a mixture of present-day radiocarbon and fossil carbon (with very low radiocarbon content), the resulting pMC value correlates directly with the amount of biomass material present in the sample.

[0122] "Bio-based materials" are organic materials made from carbon derived from CO2 recently (on a human timescale) fixed from the atmosphere through solar energy (photosynthesis). On land, this CO2 is absorbed or fixed by plants (e.g., agricultural crops or forest plantations). In the oceans, the CO2 is captured or fixed through photosynthesis by and in bacteria or phytoplankton. Thus, a bio-based material has an isotope ratio of 14 C / 12 C greater than 0. In contrast, a fossil material has a 14 C / 12 CI isotope ratio of about 0.

[0123] A small part of the carbon atoms of carbon dioxide in the atmosphere is the radioactive isotope 14C, which is formed when atmospheric nitrogen is hit by a neutron produced by cosmic radiation, causing the nitrogen to lose a proton and form carbon of atomic mass 14 ( 14 C), which is then immediately oxidized to carbon dioxide. A small but measurable portion of atmospheric carbon is in the form of 14 CO2. Atmospheric carbon dioxide is assimilated by green plants to produce organic molecules during the process known as photosynthesis. Virtually all life forms on Earth depend on the production of organic molecules by green plants to generate the chemical energy that enables growth and reproduction. Therefore, the 14 C, which forms in the atmosphere, ultimately part of all life forms and their biological products, which accumulate biomass and organisms that feed on biomass with 14C. In contrast, carbon from fossil sources, especially fuels, does not have the characteristic 14 C: 12 C ratio of renewable organic molecules derived from atmospheric carbon dioxide. The monoethylene glycol used in the coolants according to the invention has a bio-based content, measured as 14 C: 12 C ratio ASTM-D6866 of more than 0%, preferably at least 1%, more preferably at least 5%, most preferably at least 10%, in particular at least 20% and especially at least 25%.

[0124] Advantageously, this bio-based proportion can be at least 30%, preferably at least 40%, particularly preferably at least 50%, most particularly preferably at least 66%, in particular at least 75% and especially at least 85%.

[0125] If the content is at least 90%, preferably at least 95%, particularly preferably at least 98% and even 100%, this can be described as predominantly or completely bio-based monoethylene glycol.

[0126] The C-14 content of a material can be determined by determining the C-14 decays in that material using liquid scintillation. Such raw materials are preferably considered to be derived from renewable resources if they have a C-14 content that exhibits a radioactive decay of not less than 1.5 dpm / gC (decays per minute per gram of carbon), preferably 2 dpm / gC, more preferably 2.5 dpm / gC, and even more preferably 5 dpm / gC.

[0127] The monoethylene glycol used in the coolants can be obtained entirely from renewable raw materials or consist of blends of monoethylene glycol from renewable and fossil sources.

[0128] It should be emphasized that especially when monoethylene glycol is produced from Ci sources (see above), 14 C: 12 C ratio in monoethylene glycol by the 14 C: 12C ratio in the Ci source, i.e. CO and / or CO2, particularly in the CO2. If the Ci source comes partly from fossil and partly from renewable sources, the proportion of bio-based material in the product is still less than 100%. In extreme cases, if the CO2 used comes entirely from fossil material but is captured and used to produce monoethylene glycol, i.e. comes from a carbon capture and utilisation (CCU) process, the proportion of fossil carbon can be 100% and the proportion of bio-based carbon 0%. Nevertheless, monoethylene glycol obtained in this way is also inventive in that it binds CO2 and reduces the carbon footprint of the monoethylene glycol, since the product acts as a carbon sink by removing fossil-formed CO2 from the atmosphere or preventing it from entering the atmosphere, but instead utilising it.

[0129] By-product spectrum

[0130] An advantage of monoethylene glycol or monopropylene glycol obtained from renewable raw materials is that it has a lower content of their higher oligomers than products obtained from the hydrolysis of ethylene oxide or propylene oxide. As a rule, the proportion of higher oligomers, i.e., preferably di-, tri-, and tetraethylene or propylene glycol (in total), in the resulting monoethylene glycol or monopropylene glycol is less than 5 wt.%, preferably less than 3 wt.%, particularly preferably less than 2 wt.%, most preferably less than 1 wt.%, and especially less than 0.5 wt.%.

[0131] Preferably, the proportion of these higher oligomers, in particular diethylene glycol, is not more than 0.4% by weight, particularly preferably not more than 0.2% by weight, very particularly preferably not more than 0.15% by weight, in particular not more than 0.1% by weight and especially not more than 0.05% by weight.

[0132] Since these oligomers, as explained above, have a surfactant effect, monoethylene glycol or monopropylene glycol from renewable raw materials show a lower tendency to foam formation.

[0133] Depending on the manufacturing processes described from renewable raw materials, the resulting monoethylene glycol or monopropylene glycol may contain other by-products.

[0134] For example, monoethylene glycol obtained in this way can contain at least one of the specified components:

[0135] - diethylene glycol in amounts of 0.01 to 0.25% by weight, preferably 0.02 to 0.2% by weight, particularly preferably 0.03 to 0.15% by weight and very particularly preferably 0.03 to 0.1% by weight,

[0136] - 1,2-propylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight,

[0137] - 1,3-propylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight,

[0138] - 1,2-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, very particularly preferably 0.25 to 1 wt% and / or

[0139] - 2,3-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, most preferably 0.25 to 1 wt%.

[0140] A low content of diethylene glycol leads to less foaming of the coolant.

[0141] Accordingly, monopropylene glycol thus obtained may, for example, contain at least one of the specified components:

[0142] - 1,2-ethylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight,

[0143] - 1,3-propylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight,

[0144] - 1,2-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, very particularly preferably 0.25 to 1 wt% and / or - 2,3-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, very particularly preferably 0.25 to 1 wt%.

[0145] These glycols, which may be present as byproducts, also act as freezing-point-depressing components and can therefore be left in the specified amounts of monoethylene glycol or monopropylene glycol without significantly compromising their freezing-point-depressing effect. In some cases, these glycols even possess higher thermal resilience, heat capacity, or thermal conductivity than monoethylene glycol or monopropylene glycol, thus offering an advantage under the conditions of the cooling circuit.

[0146] Furthermore, glycols that contain a secondary hydroxyl group, i.e., 1,2-propylene glycol, 1,2-butylene glycol, and 2,3-butylene glycol, are more oxidation-stable than 1,2-ethylene glycol. Oxidation of 1,2-ethylene glycol produces glycolic acid, which is corrosive in the cooling system. The analogous formation of acids is more difficult with 1,2-propylene glycol and 1,2-butylene glycol, and is not significant with 2,3-butylene glycol under the conditions found in the cooling circuit.

[0147] Furthermore, they may also contain the alkanols ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol and / or iso-butanol in amounts of not more than 1% by weight each, preferably not more than 0.75% by weight, particularly preferably not more than 0.5% by weight, very particularly preferably not more than 0.25% by weight and especially not more than 0.15% by weight.

[0148] Furthermore, they may also contain the oxidation products, i.e. in the case of monoethylene glycol glycolic acid (HO-CH2-COOH), glyoxylic acid (OHC-COOH), oxalic acid (HOOC-COOH), glyoxal (OHG-CHO) and / or glycolaldehyde (HO-CH2-CHO) or the analogous products in the case of monopropylene glycol in amounts of in each case not more than 2% by weight, preferably not more than 1.5% by weight, particularly preferably not more than 1% by weight, very particularly preferably not more than 0.75% by weight and especially not more than 0.5% by weight.

[0149] An advantage of the above production processes from renewable raw materials is that the mentioned by-products have lower boiling points than the oligomers, which leads to a lower energy requirement for this production process.

[0150] coolant

[0151] The present invention therefore relates to coolants which contain monoethylene glycol and / or monopropylene glycol as freezing point lowering glycol component, preferably monoethylene glycol which has been obtained at least partly from renewable raw materials.

[0152] In particular, these are coolants containing

[0153] - at least 40% water by weight (A)

[0154] - at least 30% by weight of alkylene glycol, alkylene glycol monoalkyl ether and glycerol (B), as inhibitors (C)

[0155] - (01) optionally at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates

[0156] - (C2a) optionally benzoic acid as aromatic monocarboxylic acid

[0157] - (C2b) optionally at least one aliphatic monocarboxylic acid,

[0158] - (C3) optionally at least one organic dicarboxylic acid having 4 to 20 carbon atoms

[0159] - (04) at least one azole compound, preferably at least one triazole compound

[0160] - (D) optionally at least one inorganic base

[0161] - (E) at least one other ingredient selected from the group consisting of hard water stabilizers,

[0162] Defoamers, dyes and bittering agents, characterized in that component (B) contains at least partially monoethylene glycol and / or monopropylene glycol, preferably monoethylene glycol, which has been obtained at least partially from renewable raw materials.

[0163] (A) Water

[0164] The water used in the present invention should be neutral with a pH of around 7. This can be demineralized or distilled water, although this is not mandatory. To enable use in hard water, the composition according to the invention generally contains at least one hard water stabilizer (see below).

[0165] (B) Alkylene glycol, alkylene glycol monoalkyl ether and glycerin

[0166] Component (B) causes the main freezing point depression in the coolants.

[0167] According to the invention, component (B) contains at least partially monoethylene glycol and / or monopropylene glycol, preferably monoethylene glycol, which has been obtained at least partially from renewable raw materials.

[0168] In addition to this monoethylene glycol and / or monopropylene glycol obtained from renewable raw materials, component (B) may also contain other alkylene glycols, alkylene glycol monoalkyl ethers or glycerol which are not monoethylene glycol and / or monopropylene glycol obtained from renewable raw materials.

[0169] In a preferred embodiment of the present invention, however, component (B) consists exclusively of monoethylene glycol and / or monopropylene glycol, preferably monoethylene glycol. In a particularly preferred embodiment, at least 10% of the monoethylene glycol and / or monopropylene glycol used, preferably monoethylene glycol, is obtained from renewable raw materials, preferably at least 20%, more preferably at least 30%, most preferably at least 40%, in particular at least 50%, and especially at least 66%.

[0170] Advantageously, this proportion can be at least 75%, preferably at least 85%, particularly preferably at least 90%, very particularly preferably at least 95%, in particular at least 98% and especially even 100%.

[0171] The individuals other than component (B), which are not monoethylene glycol and / or monopropylene glycol obtained from renewable raw materials, are monomeric to tetrameric 1,2-ethylene glycols, 1,2-propylene glycols or, more rarely, 1,3-propylene glycols, preferably monomeric to trimeric 1,2-ethylene glycols or 1,2-propylene glycols, particularly preferably monomeric or dimeric 1,2-ethylene glycols, very particularly preferably monomeric 1,2-ethylene glycol, and in each case mixtures thereof.

[0172] The alkylene glycol monoalkyl ethers are the mono-Ci-C4-alkyl ethers of the above-mentioned alkylene glycols, preferably the monomethyl, ethyl or n-butyl ethers, particularly preferably the monomethyl or n-butyl ethers and very particularly preferably the monomethyl ethers.

[0173] Furthermore, glycerol or glycerol oligomers are possible components (B).

[0174] Preferred alkylene glycol components or derivatives are in particular monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol and mixtures thereof, but also monopropylene glycol, dipropylene glycol and mixtures thereof, polyglycols, glycol ethers, for example monoethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, monoethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, monoethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether and tetraethylene glycol mono-n-butyl ether, or glycerol, each used alone or as mixtures thereof.

[0175] Particularly preferred are monoethylene glycol alone or mixtures of monoethylene glycol as the main component, ie with a content in the mixture of more than 50 wt.%, in particular more than 80 wt.%, especially more than 95 wt.%, with other alkylene glycols or derivatives of alkylene glycols.

[0176] Inhibitors (C)

[0177] The inhibitors (C) act as corrosion inhibitors against metal corrosion, for example of ferrous materials, aluminum, non-ferrous metals or solder.

[0178] The compositions according to the invention contain

[0179] - (C1 ) optionally at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates and organic silicic acid esters

[0180] - (C2a) optionally benzoic acid as aromatic monocarboxylic acid

[0181] - (C2b) optionally at least one aliphatic monocarboxylic acid

[0182] - (C3) optionally at least one organic dicarboxylic acid having 4 to 20 carbon atoms

[0183] - (C4) at least one azole, preferably at least one triazole compound.

[0184] Inorganic inhibitors (C1)

[0185] The inorganic inhibitors (C1) are silicates, borates, nitrates, molybdates, or phosphates, or mixtures thereof in the form of their free acids or their salts, especially their alkali metal salts, particularly preferably their sodium or potassium salts. The form (protonated or salt) in which they are present in the compositions, superconcentrates, concentrates, or coolants depends on the respective pK. s -value of the compound and the composition as well as the pH of the respective environment, which is adjusted by the amount of base (D).

[0186] The inorganic silicates act predominantly as inhibitors of aluminum corrosion and are mostly used as alkali metal salts or, less frequently, as magnesium, calcium or aluminum salts, preferably as sodium or potassium salts.

[0187] The silicates are preferably selected from the group consisting of orthosilicates (SiO / -), metasilicates (SiOa 2- ), and pyrosilicates (Si20z 6- ), particularly preferably metasilicates (SiOa 2- ), most preferably sodium metasilicate (Na2SIO3) or potassium metasilicate (SIOs), in particular sodium metasilicate (Na2SIO3).

[0188] If the solid composition according to the invention contains at least one inorganic silicate or one organic silicic acid ester, in a preferred embodiment at least one silicophosphonate is added in addition to the silicate, as described in EP 4015596 or in WO 2022 / 043303 for silicic acid esters.

[0189] Preferably, the silicophosphonate is a compound of the general formula wherein

[0190] REPLACEMENT BLADE (RULE 26) R 5 is a divalent organic radical, preferably a 1,oo-alkylene group having 1 to 6, preferably 1 to 4 carbon atoms, particularly preferably methylene, 1,2-ethylene, 1,2-propylene, 1,3-propylene or 1,4-butylene, very particularly preferably 1,2-ethylene or 1,3-propylene and in particular 1,2-ethylene,

[0191] R 6 independently of one another hydrogen, Ci- to C alkyl or hydroxy-O 2 - to C alkyl, preferably hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, 2-hydroxyethyl or 2-hydroxypropyl, particularly preferably hydrogen, methyl, ethyl or propyl, and R 7is Ci- to C alkyl, preferably methyl, ethyl, n-propyl or n-butyl, particularly preferably methyl, ethyl or n-butyl, very particularly preferably methyl or ethyl and in particular methyl.

[0192] The silicophosphonates can be used as free acid or as alkali metal salt, preferably as sodium or potassium salt and particularly preferably as sodium salt.

[0193] The borates are preferably used as sodium tetraborate (borax) or as potassium tetraborate, particularly preferably as sodium tetraborate.

[0194] The nitrates are used as alkali or alkaline earth metal nitrates, preferably as sodium nitrate, potassium nitrate or magnesium nitrate, preferably as sodium nitrate or potassium nitrate, particularly preferably as sodium nitrate.

[0195] The phosphates are used as free acid (H3PO4), as hydrogen phosphate, dihydrogen phosphate or phosphate, preferably as sodium or potassium salt.

[0196] The use of the corresponding diphosphates, triphosphates or oligophosphates is also conceivable, but they are preferably used as monomeric phosphates.

[0197] It is preferred to use it as free acid (H3PO4), disodium hydrogen phosphate or trisodium phosphate.

[0198] Esters of orthosilicic acid are compounds of the formula

[0199] Si(OR 1 )4wherein

[0200] R 1is an organic substituent having 1 to 6 carbon atoms, for example a linear or branched, preferably a linear alkyl substituent having 1 to 6 carbon atoms or an aromatic substituent having 6 carbon atoms, more preferably an alkyl substituent having 1 to 4 carbon atoms, and most preferably an alkyl substituent having 1 or 2 carbon atoms. Alkoxyalkylsilanes are less preferred, and both the alkoxy substituent and the alkyl group comprise a linear or branched, preferably a linear alkyl substituent having 1 to 6 carbon atoms, more preferably an alkyl substituent having 1 to 4 carbon atoms, and most preferably an alkyl substituent having 1 or 2 carbon atoms.

[0201] Typical examples of compounds (D) are tetraalkoxysilanes, preferably tetramethoxysilane and tetraethoxysilane, and alkoxyalkylsilanes, preferably triethoxymethylsilane, diethoxydimethylsilane, ethoxytrimethylsilane, trimethoxymethylsilane, dimethoxydimethylsilane, and methoxytrimethylsilane. Tetraalkoxysilanes are preferred, particularly tetramethoxysilane and tetraethoxysilane, with tetraethoxysilane being most preferred.

[0202] The components (C1) are preferably at least one compound selected from the group consisting of silicates, borates, nitrates or phosphates, particularly preferably at least one compound selected from the group consisting of silicates, nitrates or phosphates.

[0203] (C2a) Aromatic monocarboxylic acid

[0204] The optional aromatic monocarboxylic acid is preferably benzoic acid, which can be used as the free acid or particularly preferably in the form of its alkali metal salt, most preferably as sodium benzoate.

[0205] In a preferred embodiment of the present invention, no aromatic monocarboxylic acid is present.

[0206] (C2b) Aliphatic monocarboxylic acids

[0207] Aliphatic monocarboxylic acids are organic aliphatic alkane or alkenecarboxylic acids. Provided they are sufficiently water-soluble, they are frequently used in coolants as corrosion inhibitors against the corrosion of ferrous materials. These aliphatic monocarboxylic acids preferably have 5 to 12 carbon atoms, more preferably 6 to 10, and most preferably 8, 9, or 10.

[0208] Typical monocarboxylic acids of this type are pentanoic acid, 2,2-dimethylpropanoic acid, hexanoic acid, 2,2-dimethylbutanoic acid, octanoic acid, 2-ethylhexanoic acid, n-nonanoic acid, isononanoic acid, decanoic acid, undecanoic acid, and dodecanoic acid, as well as their isomer mixtures, in particular 2-ethylhexanoic acid, n-nonanoic acid, and isononanoic acid isomer mixtures. However, one possible embodiment is to use the aliphatic monocarboxylic acids in the form of their alkali metal salts, preferably in the form of their lithium, sodium, or potassium salts, particularly preferably in the form of their sodium or potassium salts, instead of the free acid.

[0209] (C3) Organic dicarboxylic acid containing 4 to 20 carbon atoms

[0210] The organic dicarboxylic acids having 4 to 20 carbon atoms are linear or branched alkanedicarboxylic acids, preferably linear alkane or alkenedicarboxylic acids, particularly preferably linear alkanedicarboxylic acids, particularly preferably having 5 to 14 and very particularly preferably having 6 to 12 carbon atoms.

[0211] Preferably, the dicarboxylic acids (C3) are selected from the group consisting of succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid (heptanedioic acid), azelaic acid (nonanedioic acid), sebacic acid (decanedioic acid), undecanedioic acid, dodecanedioic acid, as well as alkyl and alkenyl succinic acids and glutaric acids such as 2-methylbutanedioic acid, 2-ethyl-3-methylbutanedioic acid, 2-ethylpentanedioic acid, 2-dodecylbutanedioic acid, 2-dodecenylbutanedioic acid, 2-phenylbutanedioic acid, 2-(p-methylphenyl)butanedioic acid, 2,2-dimethylbutanedioic acid, 2,3,4-trimethylpentanedioic acid, 2,2,3-trimethylpentanedioic acid, glutaconic acid (pent-2-enedioic acid), itaconic acid, hex-2- enedioic acid, hex-3-enedioic acid, 5-methyl-hex-2-enedioic acid and 2,3-dimethyl-pent-2-enedioic acid.

[0212] Among these, preferred are the dicarboxylic acids having 6 to 12 carbon atoms, particularly preferred among these are the alkanedicarboxylic acids having 6 to 12 carbon atoms, very particularly preferred are the linear alkanedicarboxylic acids having 6 to 12 carbon atoms.

[0213] Particularly preferred dicarboxylic acids (D3) are adipic acid, sebacic acid, azelaic acid and dodecanedicarboxylic acid.

[0214] (C4) Azole compound

[0215] In the context of this document, azole derivatives (C4) are defined as five-membered heterocyclic compounds with 2 or 3 heteroatoms from the group nitrogen and sulfur, which contain no or a maximum of one sulfur atom incorporated into the ring and which can optionally carry an aromatic or saturated six-membered anellant.

[0216] These five-membered heterocyclic compounds (azole derivatives) usually contain two N atoms and no S atom, three N atoms and no S atom, or one N atom and one S atom as heteroatoms. Preferred groups of the above-mentioned azole derivatives are fused imidazoles and fused 1,2,3-triazoles of the general formula or (IV) in which the variable

[0217] R is hydrogen or a C 1 -C 10 -alkyl radical, in particular methyl or ethyl, and the variable X is a nitrogen atom or the group CH.

[0218] Typical and preferred examples of azole derivatives of the general formula (III) are benzimidazole (X = CH, R = H), benzotriazole (X = N, R = H), and tolutriazole (tolyltriazole) (X = N, R = CH3). A typical example of an azole derivative of the general formula (IV) is hydrogenated 1,2,3-tolutriazole (tolyltriazole) (X = N, R = CH3).

[0219] Another preferred group of the azole derivatives mentioned are benzothiazoles of the general formula (V) in which the variable R has the meaning given above and the variable R' denotes hydrogen, a Ci- to Cw-alkyl radical, in particular methyl or ethyl, or in particular a mercapto group (-SH). Conceivably, although less preferably, R' can also be a carboxyalkyl radical of the formula -(C m H2m)-C00R", where m is a number from 1 to 4 and R" is hydrogen or C1- to C8-alkyl, in particular methyl or ethyl, or C9- to C12-aryl. Examples of these are (2-benzothiazolethio)-

[0220] REPLACEMENT SHEET (RULE 26) acetic acid, (2-benzothiazylthio)acetic acid ester, 3-(2-benzothiazylthio)propionic acid, or 3-(2-benzothiazylthio)propionic acid ester. If these compounds are used as acids, they are not among the carboxylic acids excluded according to the invention. A typical example of an azole derivative of the general formula (V) is 2-mercaptobenzothiazole.

[0221] Furthermore, non-fused azole derivatives of the general formula (VI) in which the variables

[0222] X and Y together denote two nitrogen atoms or one nitrogen atom and a group CH, for example 1 H-1,2,4-triazole (X = Y = N) or preferably imidazole (X = N, Y = CH).

[0223] Benzimidazole, benzotriazole, tolutriazole, hydrogenated tolutriazole or mixtures thereof, in particular benzotriazole or tolutriazole, especially tolutriazole, are very particularly preferred as azole derivatives for the present invention.

[0224] The azole derivatives mentioned are commercially available or can be prepared using conventional methods. Hydrogenated benzotriazoles such as hydrogenated tolutriazole are also accessible according to DE-A 1 948794 and are also commercially available.

[0225] Preferably, the azoles are selected from the group consisting of benzotriazole, tolutriazole, (2-benzothiazylthio)acetic acid, 3-(2-benzothiazylthio)propionic acid and 2-mercaptobenzothiazole.

[0226] (D) Inorganic base

[0227] The pH value of the antifreeze at the end user is usually in the range of 4 to 11.5, preferably 5 to 10, especially 6 to 9.

[0228] To adjust this pH value, at least one inorganic base (D) is added at any stage during the manufacturing process of the coolant from a concentrated precursor. The at least one inorganic base can be present in the composition according to the invention, in the superconcentrate or in the concentrate.

[0229] REPLACEMENT LEAF (RULE 26) or added in the preparation of the super concentrate from the composition according to the invention by mixing with component (A) and / or (B), in the preparation of the concentrate from the super concentrate by mixing with component (A) and / or (B) or in the preparation of the coolant from the concentrate by mixing with component (A) and / or (B).

[0230] Therefore, the compositions according to the invention optionally contain an amount of inorganic base which, when appropriately diluted in the coolant, establishes this desired pH value. For this purpose, the compositions according to the invention preferably contain alkali metal hydroxide, particularly preferably solid lithium, sodium, or potassium hydroxide, optionally also in the form of aqueous lithium, sodium, or potassium hydroxide solution.

[0231] Less preferred are carbonates or bicarbonates of lithium, sodium or potassium.

[0232] Preferred alkali metals are sodium and potassium.

[0233] In a preferred embodiment, at least part of the inorganic base, preferably the entire required inorganic base, is already contained in the composition according to the invention. This has the advantage, on the one hand, that the base no longer needs to be added at a later stage of production, thus eliminating the risk of incorrect dosing. On the other hand, the added acids are present in their alkali metal salt form, which is usually more easily crystallized, which facilitates the formulation of the solid composition according to the invention as a solid.

[0234] (E) Other ingredients selected from the group consisting of hard water stabilizers, defoamers, colorants and bittering agents

[0235] As further conventional auxiliaries, the compositions according to the invention may also contain, in the usual small amounts, defoamers (usually in amounts of 0.003 to 0.008% by weight in the ready-diluted coolant) as well as, for reasons of hygiene and safety in case of ingestion, bittering agents (e.g. of the denatonium benzoate type) and dyes.

[0236] The composition may also contain one or more hard water stabilizers based on polyacrylic acid, polymaleic acid, acrylic acid-maleic acid copolymers, polyvinylpyrrolidone, polyvinylimidazole, vinylpyrrolidone-vinylimidazole copolymers, and / or copolymers of unsaturated carboxylic acids and olefins. The proportion in the composition is selected so that, after appropriate dilution, the amount in the final diluted coolant is up to 1 wt.%.

[0237] Concentrates, Super Concentrates: To reduce the volumes to be transported, coolants with high water content are usually not sold, but rather concentrates in which the water content is omitted or significantly reduced. The coolants are produced by the end user from the concentrates by adding water.

[0238] To further reduce the volumes to be transported, so-called super concentrates are often produced centrally. These super concentrates omit or significantly reduce not only the water but also the glycol content. These super concentrates are then produced regionally by formulators by blending them with glycols.

[0239] According to the invention, it is essential that these glycols used for blending meet the inventive requirement of being obtained at least partially from renewable raw materials.

[0240] Another object of the present invention are coolant concentrates containing

[0241] - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A)

[0242] - at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B) as inhibitors (C)

[0243] - (C1) optionally at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates

[0244] - (C2a) optionally benzoic acid as aromatic monocarboxylic acid

[0245] - (C2b) optionally at least one aliphatic monocarboxylic acid,

[0246] - (C3) optionally at least one organic dicarboxylic acid having 4 to 20 carbon atoms

[0247] - (C4) at least one azole, preferably at least one triazole compound

[0248] - (D) optionally at least one inorganic base

[0249] - (E) at least one other component selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents in which component (B) at least partially contains monoethylene glycol and / or monopropylene glycol, preferably monoethylene glycol which has been obtained at least partially from renewable raw materials.

[0250] Another object of the present invention are coolant superconcentrates containing

[0251] - not more than 15, preferably not more than 10 and particularly preferably not more than 5 wt% water (A)

[0252] - at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B) as inhibitors (C)

[0253] - (C1) optionally at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as aromatic monocarboxylic acid

[0254] - (C2b) optionally at least one aliphatic monocarboxylic acid,

[0255] - (C3) optionally at least one organic dicarboxylic acid having 4 to 20 carbon atoms

[0256] - (C4) at least one azole, preferably at least one triazole compound

[0257] - (D) optionally at least one inorganic base

[0258] - (E) at least one other component selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents in which component (B) at least partially contains monoethylene glycol and / or monopropylene glycol, preferably monoethylene glycol which has been obtained at least partially from renewable raw materials.

[0259] A further subject of the present invention is a process for producing the above-mentioned coolant concentrates from the above-mentioned coolant superconcentrates, in which a coolant superconcentrate is admixed with the appropriate amount of at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol (B), with the proviso that monoethylene glycol and / or monopropylene glycol is used as component (B), preferably monoethylene glycol which has been obtained at least partly from renewable raw materials.

[0260] Sustainability indicators

[0261] A further subject matter of the present invention is a process for reducing emissions during the production of alkylene glycol-containing coolants, for example nitrogen oxide and sulfur oxide emissions and in particular carbon dioxide emissions, preferably determined as a carbon footprint, life cycle assessment or in accordance with DIN EN ISO 14021, DIN EN ISO 14067, here in particular the 2019-02 edition, DIN EN ISO 14044, here in particular the 2006 +A1:2018 edition and / or DIN EN ISO 14040, here in particular the 2009-11 edition, in which monoethylene glycol and / or monopropylene glycol is used at least partially in the production of the coolant, preferably monoethylene glycol which has been obtained at least partially from renewable raw materials.

[0262] To determine the life cycle assessment, DIN EN ISO 14040, in particular the 2009-11 edition and / or DIN EN ISO 14044, in particular the 2006 + A1:2018 edition, are preferred.

[0263] To determine the carbon footprint, DIN EN ISO 14067, particularly the 2019-02 edition, is preferred. By producing monoethylene glycol and / or monopropylene glycol from renewable raw materials, the disadvantages listed above are avoided, so that the resulting monoethylene glycol and / or monopropylene glycol have a more favorable life cycle assessment and / or a lower carbon footprint. Even if the CO2 used comes entirely from fossil material but is captured and used to produce monoethylene glycol, i.e., from a carbon capture and utilization (CCU) process, the proportion of fossil carbon can be 100% and the proportion of bio-based carbon can be 0%.Nevertheless, a monoethylene glycol obtained in this way is also in accordance with the invention in that it binds CO2 and reduces the carbon footprint of the monoethylene glycol, since the product acts as a carbon sink by removing fossil-formed CO2 from the atmosphere or preventing it from entering the atmosphere, but rather utilizing it.

[0264] In the case described above, in which monoethylene glycol is produced entirely or partially from ethylene oxide or ethene from renewable raw materials, for example as described above from the dehydration of ethanol from glucose, the advantage of the process according to the invention does not lie in the avoidance of ethylene oxide handling, but in this approach at least partially renewable raw materials are used in the production of the monoethylene glycol, so that this production also has a more favorable ecological balance and / or a lower carbon footprint than production from entirely fossil raw materials.

Claims

Claims 1. Coolant containing - at least 40% water by weight (A) - at least 30% by weight of alkylene glycol, alkylene glycol monoalkyl ether and glycerol (B), as inhibitors (C) - (C1) optionally at least one inorganic compound selected from the group consisting of silicates, borates, nitrates, molybdates and phosphates - (C2a) optionally benzoic acid as aromatic monocarboxylic acid - (C2b) optionally at least one aliphatic monocarboxylic acid, - (C3) optionally at least one organic dicarboxylic acid having 4 to 20 carbon atoms - (C4) at least one azole compound, preferably at least one triazole compound - (D) optionally at least one inorganic base - (E) at least one other component selected from the group consisting of hard water stabilizers, defoamers, dyes and bittering agents, characterized in that component (B) at least partially contains monoethylene glycol and / or 1,2-propylene glycol, preferably monoethylene glycol, which has been obtained at least partially from renewable raw materials, wherein the bio-based content, measured as 14 C / 12 C isotope ratio according to ASTM D 6866 of the monoethylene glycol and / or 1,2-propylene glycol used, preferably monoethylene glycol, is more than 0%, preferably at least 1%, particularly preferably at least 5%, very particularly preferably at least 10%, in particular at least 20% and especially at least 25%.

2. Coolant according to claim 1, characterized in that the component (B) used contains monoethylene glycol and / or 1,2-propylene glycol, preferably monoethylene glycol, which is obtained at least partially by conversion of carbon dioxide (CO2) and / or carbon monoxide (CO) by genetically modified microorganisms and / or enzymes.

3. Coolant according to claim 1, characterized in that the component (B) used contains monoethylene glycol, which is obtained at least partially by reducing glycolic acid (HO-CH2-COOH), glyoxylic acid (OHC-COOH), oxalic acid (HOOC-COOH), glyoxal (OHC-CHO) and / or glycolaldehyde (HO-CH2-CHO) or mixtures thereof, originating from natural sources or obtained from renewable raw materials.

4. Coolant according to claim 1, characterized in that the component (B) used contains monoethylene glycol and / or 1,2-propylene glycol, preferably monoethylene glycol, which, at least partially from ethene or propene from the splitting of renewable raw materials, followed by its conversion to ethylene oxide or propylene oxide and subsequent conversion to monoethylene glycol or 1,2-propylene glycol.

5. Coolant according to claim 1, characterized in that the component (B) used contains monoethylene glycol and / or 1,2-propylene glycol, preferably monoethylene glycol, which is obtained by cleavage of optionally repeating organic compounds of a renewable raw material having at least three carbon atoms.

6. Coolant according to claim 5, characterized in that the organic compound of a renewable raw material is selected from the group consisting of sugar, starch, fibers, lignin, cellulose and hemicellulose.

7. Coolant according to claim 5, characterized in that the organic compound of a renewable raw material is a monomer or biopolymer based on arabinose, fructose, galactose, glucose, lactose, mannose, maltose, sucrose and / or xylose.

8. Coolant according to claim 5, characterized in that a carbohydrate substrate is converted by hydrolysis, fermentation, pyrolysis or hydrogenolysis to monoethylene glycol and / or their precursors selected from the group consisting of glycolic acid (HO-CH2-COOH), glyoxylic acid (OHC-COOH), oxalic acid (HOOC-COOH), glyoxal (OHC-CHO) and / or glycolaldehyde (HO-CH2-CHO) or mixtures thereof, and any precursors are converted into monoethylene glycol by reduction.

9. Coolant according to one of the preceding claims, characterized in that the bio-based content, measured as 14 C / 12 C isotope ratio according to ASTM D 6866 of the monoethylene glycol and / or 1,2-propylene glycol used, preferably monoethylene glycol, is at least 30%, preferably at least 40%, particularly preferably at least 50%, very particularly preferably at least 66%, in particular at least 75% and especially at least 85%.

10. Coolant according to one of the preceding claims, characterized in that the component (B) obtained from renewable raw materials is monoethylene glycol which contains at least one of the specified components: - diethylene glycol in amounts of 0.01 to 0.25% by weight, preferably 0.02 to 0.2% by weight, particularly preferably 0.03 to 0.15% by weight and very particularly preferably 0.03 to 0.1% by weight, - 1,2-propylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight, - 1,3-propylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 up to 2% by weight, most preferably 0.25 to 1% by weight, - 1,2-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, very particularly preferably 0.25 to 1 wt% and / or - 2,3-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, most preferably 0.25 to 1 wt%.

11. Coolant according to one of claims 1 to 9, characterized in that the component (B) obtained from renewable raw materials is 1,2-propylene glycol which contains at least one of the specified components: - 1,2-ethylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight, - 1,3-propylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight, - 1,2-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, very particularly preferably 0.25 to 1 wt% and / or - 2,3-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, most preferably 0.25 to 1 wt%.

12. Use of monoethylene glycol and / or 1,2-propylene glycol, preferably monoethylene glycol, which has been obtained at least partly from renewable raw materials, in coolants.

13. Use of a monoethylene glycol according to claim 12 containing diethylene glycol in amounts of 0.01 to 0.25% by weight for reducing foam formation in coolants.

14. Use of a monoethylene glycol according to claim 12 containing - diethylene glycol in amounts of 0.01 to 0.25% by weight, preferably 0.02 to 0.2% by weight, particularly preferably 0.03 to 0.15% by weight and very particularly preferably 0.03 to 0.1% by weight, - 1,2-propylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight, - 1,3-propylene glycol in amounts of 0.05 to 5% by weight, preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, very particularly preferably 0.25 to 1% by weight, - 1,2-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, very particularly preferably 0.25 to 1 wt% and / or - 2,3-butylene glycol in amounts of 0.05 to 5 wt%, preferably 0.1 to 3 wt%, particularly preferably 0.2 to 2 wt%, very particularly preferably 0.25 to 1 wt% to increase the thermal load capacity, heat capacity, thermal conductivity and / or oxidation stability. quality of the freezing point lowering component in a coolant.

15. A process for reducing emissions during the production of alkylene glycol-containing coolants, for example nitrogen oxide and sulfur oxide emissions and in particular carbon dioxide emissions, preferably determined as a carbon footprint, life cycle assessment or in accordance with DIN EN ISO 14021, DIN EN ISO 14067, here in particular the 2019-02 edition, DIN EN ISO 14044, here in particular the 2006 + A1:2018 edition and / or DIN EN ISO 14040, here in particular the 2009-11 edition, characterized in that monoethylene glycol and / or 1,2-propylene glycol is used at least partially in the production of the coolant, preferably monoethylene glycol which has been obtained at least partially from renewable raw materials.

Images