Process for the production of ammonia and urea from bioethanol

Abstract

A process for the production of ammonia and urea, characterized in that bioethanol or aqueous solutions of bioethanol 2, obtained by alcoholic fermentation, are subjected to an auto- or endothermic steam reforming and a subsequent CO conversion 3, hydrogen 8 and CO2 7, which are produced in this process, are obtained from the raw synthesis gas in a gas separation plant 5, from the hydrogen 8, together with a stoichiometric amount of nitrogen 10 from an air separation plant 9, ammonia 12 is then formed in a synthesis cycle system 11 and separated by cooling and condensation, and finally this ammonia 12 is converted together with the previously separated CO2 7 in a downstream urea plant 13 to urea 14, wherein the CO2 15, which is produced during the bioethanol production, is separated and used for the production of further urea 17 becomes.

Description

[0001] The invention relates to a process for the production of ammonia and urea, in which both reactants required for urea synthesis, namely ammonia and carbon dioxide, are produced in an ammonia plant exclusively from bioethanol. State of the art

[0002] Given the dramatic climate changes caused by the emission of large amounts of carbon dioxide (CO2) from the use of fossil fuels, it is necessary to find the fastest possible ways to prevent further increases in the CO2 content in the atmosphere, not only in the energy and heat sectors, the largest emitters, but also in the materials sector. The framework for this is the global goal of gradually phasing out the use of coal, oil, and gas over the next decades. For Germany, a climate protection law was passed in 2021, which stipulates that greenhouse gas neutrality must be achieved by 2045.

[0003] While it appears fundamentally possible to achieve this goal in the energy sector through the use of renewable electricity or hydrogen derived from it, it is a major challenge for the production of organic products in the materials industry to find alternatives to the absolutely necessary carbon or its oxides CO and CO2, which have so far been available almost exclusively from fossil raw materials.

[0004] Among industrial-scale organic products, urea, the production of which is the subject of this invention, occupies a special position. Its annual global production is approximately 200 million tons, for which demand will continue unabated or even increase. Doing without these plants in the long term is not an option, if only because of urea's immense importance as a nitrogen fertilizer. Supplying agriculture exclusively with carbon-free nitrogen fertilizers, i.e., nitrates, ammonium sulfates, or ammonium phosphates, is unthinkable. Urea has dominated nitrogen fertilizers for decades, accounting for approximately 60%, primarily because it has the highest nitrogen content and the lowest production costs.

[0005] The raw materials for its production, ammonia and CO2, are provided by ammonia plants, which are therefore essential to the following considerations. The global annual production of these plants is also considerable, at approximately 170 million tons.

[0006] Ammonia, a synthesis product of hydrogen and nitrogen, is currently produced exclusively from fossil, carbon-containing raw materials. Regardless of whether coal, oil, or gas, the synthesis gas production process always produces both hydrogen and CO2. To this day, the production of urea, which is synthesized from it together with ammonia, is based exclusively on this inevitable production. Therefore, all existing urea plants are generally coupled with ammonia plants.

[0007] The following statements are based on the typical specific consumption figures of modern ammonia-urea complexes: 2050 Nm 3 H2 / t ammonia 0.57 t ammonia / t urea and thus 1169 Nm 3 H2 / t urea 375 Nm 3 CO2 / t urea

[0008] This results in the optimal H2 / CO2 ratio in the synthesis gas of ammonia plants for downstream urea plants: 1169 / 375 = 3.1. Any deviation, whether upward or downward, inevitably leads to a larger amount of the raw material used for synthesis gas production.

[0009] Most ammonia plants are currently based on natural gas due to their significant cost advantage. However, compared to coal- or oil-based plants, they have one somewhat undesirable characteristic: During the chemical conversion of natural gas, essentially methane, stoichiometric constraints always produce more ammonia than the CO2 required for its complete conversion into urea. The H2 / CO2 ratio is approximately 3.6 in most plants using secondary reformers and 4.0 in plants with separate nitrogen feed. As a result, these ammonia-urea complexes always have an ammonia surplus of 10 to 20%, which must either be continuously sold to third parties or processed in further processing plants, for example, into nitric acid.

[0010] Urea's impact on atmospheric CO2 pollution is very direct: Due to its primary use as a nitrogen fertilizer, but also as a denitrification agent for diesel engine exhaust, the CO2 is released into the atmosphere very quickly after hydrolytic decomposition. Its annual production therefore conceals both the material demand and the considerable emission of approximately 150 million tons of CO2, without taking into account the precursors.

[0011] If the sole purpose is to produce the raw material ammonia for urea synthesis, technologies that do not emit CO2 are now available. One study (1, p. 10), for example, sees good long-term prospects for coal-based plants in which the resulting CO2 is separated and stored using CCS (Carbon Capture Storage). A similar approach is presented in (2) for natural gas as a basis. However, the prerequisites for such plants would be the unlikely continued long-term extraction of fossil fuels and, last but not least, the availability of extremely large, reliable CO2 storage facilities.

[0012] It has also been described several times that the hydrogen required for ammonia synthesis can be produced by electrolysis and the necessary nitrogen by air separation. (e.g., CN 000115259178A, WO 002010128682A1, WO 0002013156842A1, WO 002017149718A1) However, according to the current state of the art, summarized in a comprehensive VCI study (3, p. 31), the electricity requirement for hydrogen is 4.4 kWh / Nm 3 and can be reduced to 3.6 kWh / Nm 3 This would correspond to 7.38 MWh / t of ammonia. With a hydrogen demand for a currently quite common 3000 t / d plant of around 260,000 Nm 3 / h, an electrical output of about 920 MW would still be required. For comparison: a currently common natural gas-based ammonia plant consumes about 600 Nm 3 Methane / t ammonia, which corresponds to 5.98 MWh / t ammonia (H u of methane = 9.97 kWh / Nm 3This means that even if electricity consumption can be minimized as described, the energy consumption of a future plant based on electrolysis hydrogen will still be 23% higher than that of natural gas. If one also considers that the price of electricity is two to three times higher than that of natural gas, this disadvantage is significantly increased.

[0013] In contrast, the power requirement of an air separation plant for the stoichiometric amount of nitrogen, namely about 85,000 Nm 3 / h, already according to the current state of the art only about 13 MW (0.15 kWh / Nm 3 ). A separate, cost-effective nitrogen supply for future ammonia plants is thus relatively easy.

[0014] The above VCI study (3, p. 33) expects, given the high electricity demand for hydrogen, that future ammonia plants will be more than ten times smaller in capacity than current ones. This would not only significantly increase the specific investment and operating costs of new plants, but also leave the question completely open as to what would happen to the large number of existing large-scale plants. Therefore, this scenario is likely to be a rather unrealistic one.

[0015] According to another study (4), it will be extremely difficult for Germany to meet its immense fossil-free hydrogen demand in the future. Demand is estimated at 2.7 to 3.3 million tonnes of hydrogen in 2030, of which domestic production of only 0.4 million tonnes is expected. This is considerably lower than the current demand-supply capacity of approximately 1.65 to 1.8 million tonnes based on fossil fuels (5) and corresponds to only about 4.5 billion Nm³. 3 / a. Germany will therefore be dependent on imports for 85 to 88% of its hydrogen needs in the future. An ammonia plant of the above-mentioned capacity alone would require 2 billion Nm 3 / a require about 45% of the own production.

[0016] Given the difficulties in providing fossil-free hydrogen, several ammonia production processes have been proposed in which only a portion of the hydrogen is produced electrolytically and the remainder is produced, as is the case today, using fossil hydrocarbons (e.g., EP 000003658489B1, EP 000003658492B1, DE 102021213799A1). While this reduces CO2 emissions, it does not achieve the goal of complete elimination.

[0017] An alternative to electrolysis could be offered by various works (e.g. 4, 6, 7, 8, 9, 10) dealing with the production of hydrogen from bio-raw materials, whereby the focus is on its production for energetic purposes, e.g. biofuels, but not for material applications.

[0018] If it were actually possible to make the immense quantities of hydrogen required for ammonia production available at one location without CO2 pollution of the atmosphere using one of the methods described, then the supply of ammonia for downstream urea plants would be secured, but a way for the climate-neutral provision of the required CO2 would still have to be found.

[0019] This challenge is by no means solved according to the current state of technology, primarily due to the extremely large quantities of CO2 required. A perfectly normal 3000 t / d urea complex, for example, requires approximately 47,000 Nm3, or 94 tons of CO2, per hour. The findings of the aforementioned fundamental study on a greenhouse gas-neutral future by 2050 (3, p. 36) are correspondingly vague. It merely assumes that, in addition to green ammonia, the required CO2 for the urea process will be "imported," without specifying the sources. The use of CO2 from chemical processes or other industrial sources as a form of reuse, discussed there as an example, is unfortunately not effective, since the CO2 then enters the atmosphere not directly, but after its reuse, via the detour of urea.

[0020] This CO2 problem also applies to the economically significant global production of approximately 100 million t / a of methanol, and is therefore included in the analysis. While urea requires a precursor, ammonia, in addition to CO2, for its production, methanol is produced directly from hydrogen and carbon monoxide (CO), or carbon dioxide (CO2). Existing methanol plants are therefore based on the same fossil carbon carriers as ammonia plants.

[0021] Whether it is methanol, urea or other carbon-containing chemical products such as ethylene, propylene or aromatics, the only thing that is clear is that for a future without fossil feedstocks, the extraction of the carbon required for them will be reduced to just two sources: the air and biological raw materials.

[0022] Various studies are addressing the former approach. However, extracting CO2 economically from the air using so-called direct air capture (DAC) is not yet very promising, given the low concentration of approximately 0.04% on the one hand and the extremely high CO2 demand on the other. To illustrate: The urea plant described above requires approximately as much CO2 per hour as about 120 million Nm3 3of air, i.e. an air cube with an edge length of approximately 490 m! Initial semi-technical plants (11) using various technologies require 1000 kWh of electricity per t CO2 alone. But even extensive long-term forecasts, e.g. for the removal of 20 Mt CO2 / a from the atmosphere using DAC in Germany in 2045 (12), are not particularly encouraging: According to these figures, 620 kWh of electricity and 945 kWh of heat are to be expected per ton of CO2. In addition, there is an extremely large area and investment requirement. For the 3000 t / d urea plant described above, 5.3 to 6.4 km 2 area to be developed is required, which is solely due to the DAC.

[0023] Since relevant process improvements in both DAC and the electrolytic production of hydrogen do not necessarily lead to an economic solution in the near future, it is interesting to monitor the extent to which progress has been made in the alternative, the material use of biomass, in which it is in principle possible to simultaneously produce hydrogen and CO or CO2, i.e. the components required both for methanol production directly and for urea production indirectly via ammonia production.

[0024] There are several studies on ammonia production. Examples: In CN 000115385300A, biowaste is pyrolytically processed to produce bio-oil, which is then reformed. In US 020220340419A1 and US 000010995009B2, biomass is gasified with oxygen from water electrolysis, so that the hydrogen comes proportionally from the gasification and electrolysis. A similar approach is described in US 020100040527A1. In US 020110144389A1, pelleted biomass is gasified to produce hydrogen. In all cases, the nitrogen for ammonia synthesis is provided separately, either through air separation or by separation from flue gases.

[0025] All of these processes have the major disadvantage that only relatively small amounts of hydrogen and carbon can be extracted from the biomass, so that the annual demand for the corresponding raw material in large-scale plants would be in the millions of tons range. Unfortunately, there are no corresponding examples of implementation for the processes proposed so far for urea plants. However, such data are available for the production of methanol. (3, pp. 39 / 40, 13) This can be easily applied to ammonia, since the specific hydrogen demand for both is approximately 2050 (ammonia) and 2150 Nm³, respectively. 3 / t (methanol) is almost identical.

[0026] In one specific process (3, pp. 39 / 40), wood or sugar beets are gasified with the aim of producing the synthesis gas required for a conventional methanol plant. According to experience with this 300 t / d ThyssenKrupp plant, either 2.56 t of wood or 8 t of sugar beets are needed as raw material for one metric ton of methanol. Even this pilot plant has an annual consumption of approximately 260,000 t of wood or 800,000 t of sugar beets. The reason for this: The water content of fresh wood is approximately 50%, and that of sugar beets as high as 75%. Both the provision and processing of the quantities required for large-scale plants with typical capacities of 3,000 t / d and more at a single location would likely be an almost insurmountable challenge.

[0027] Since, as previously explained, ammonia and methanol have almost the same specific hydrogen requirements for their production, these statements apply equally to both products.

[0028] While there is already a specific process plant for the CO2-neutral production of methanol from biological raw materials—as described above—this is not the case for urea. This may be due to the fact that its production consists of two separate processes: the ammonia process and the urea process. For the ammonia process, the primary concern is the most cost-effective supply of hydrogen, while for the urea process, the primary concern is the supply of CO2. After all, there are now a number of patents dealing with ammonia-urea complexes based on various biomasses, for example, CA 000002789554A1, US 020180065923A1, JP 002013170086A, ES 000002573717A1, EP 000003321251A2, and US 000009738598B2. The latter invention also attempts to address the above-mentioned fact that it is logistically difficult to manage the installation of large capacities at one location.Therefore, the individual process stages take place in mobile, low-capacity modules, making it possible to have the biomass processing or even the entire process take place at different biomass generation sites. However, it is difficult to imagine that this would be economically feasible.

[0029] Given the current state of knowledge regarding the fossil-free production of ammonia and urea, it is surprising that no proposals have been made for the material use of the largest bio-based non-food products in terms of volume and the most concentrated in terms of hydrocarbon content, namely bioethanol and vegetable oils for biodiesel. After all, in Germany alone, annual consumption of the former amounts to 1.19 million tons and the latter to 3.9 million tons.

[0030] Bioethanol is produced through alcoholic fermentation and is currently used as a fuel or fuel additive for vehicles with gasoline-based combustion engines, primarily cars. This application requires a purity of over 99%, so dehydrating the alcohol-water mixture produced after the fermentation process in bioethanol plants requires three energy-intensive steps: distillation, rectification to near the azeotropic point, and finally molecular sieve drying.

[0031] Biodiesel, i.e., esterified vegetable oil, is also used as a fuel blend, but for vehicles with diesel engines. The process from vegetable oil to fuel-grade end product is very complex, similar to that for bioethanol. Among other things, each ton of product requires approximately 0.1 tons of methanol, previously produced using fossil fuels, and approximately 1 ton of steam for energy. At the same time, 0.13 tons of glycerol are inevitably produced, which must be marketed.

[0032] With the gradual replacement of all combustion engines with alternative drive systems, the current use of these fuel additives will be completely eliminated in the medium term. However, an EU directive (REDII, 2018 / 2001 / EU) will come into force much earlier, namely in 2030, revising the existing Renewable Energy Directive (RED 2009 / 28 / EU). According to this directive, biofuels may no longer be placed on the market if they originate from raw materials that can be used as food or animal feed, which has largely been the case so far (potatoes, corn, sugar beets, rapeseed, etc.). To ensure that biofuels remain available after 2030, they must be produced exclusively from organic waste.

[0033] A single – albeit only energetic – alternative to the current use of bioethanol and vegetable oil is discussed in a comprehensive study (13). These, along with various other energy sources, are compared with regard to their suitability for the production of hydrogen for stationary CHP plants based on fuel cells. Of fundamental importance is the realization that vegetable oils are the least suitable for this purpose, since the amount of hydrogen produced, relative to the yield of oilseed per hectare of cultivated land, is only 1 / 3 to 2 / 3 of what is achieved with bioethanol. This has to do with both their chemical composition (molecular formula C 77 H 12 O 11), as well as the disadvantage that hydrogen can only be obtained through autothermal reforming, compared to the more effective steam reforming of ethanol. From the data in this study, it can also be deduced through conversions that not only is the hydrogen production comparatively low in vegetable oils, but also that the H2 / CO2 ratio of approximately 1.7 is extremely unfavorable for optimal urea production.

[0034] Further detailed studies (14, 15) deal exclusively with the use of bioethanol for hydrogen production for fuel cells.

[0035] A specific application of bioethanol-based fuel cells is described in (16). It involves their use in electric vehicles, which obtain their power in this way. By producing hydrogen through reforming and then converting it into electricity, the efficiency of ethanol utilization is increased compared to its direct combustion in an internal combustion engine. The large-scale introduction of such a solution faces at least two significant challenges: the considerable technical and technological effort required for each vehicle, and the availability of the required quantities of bioethanol given EU restrictions on its production for energy use. Description of the invention

[0036] The aim of the present invention is to completely eliminate the use of fossil raw materials for the production of ammonia and urea without having to accept the disadvantages associated with the state of the art. In particular, the extremely high expenditure for producing hydrogen by electrolysis and CO2 by enriching it from the air is to be avoided. Furthermore, the aim of the remaining alternative, namely the use of bio-based materials, is to use a raw material that, unlike previously, allows the continued operation of existing plants with large capacities and the construction of corresponding new plants due to its specifically low quantity requirements and the best possible material properties.

[0037] According to the invention, this problem is solved by using bioethanol as the raw material for the production of ammonia synthesis gas. It is homogeneous, has a high hydrocarbon content, can be easily stored at atmospheric pressure and ambient temperature, and allows for energy-efficient pressure increase using pumps. Production can take place at various locations, as transportation is straightforward.

[0038] The bioethanol is first compressed to a liquid state, evaporated, and then, in a mixture with water and steam, subjected to steam reforming and subsequent CO conversion. The resulting raw synthesis gas is first subjected to water removal by cooling and condensation in the usual way, and then the two reactants, CO2 and hydrogen, are separated from the residual gas. In a similarly conventional manner, the hydrogen thus obtained and the nitrogen stoichiometrically required for ammonia, preferably from an air separation plant, are then compressed to the pressure required for ammonia synthesis and converted there into ammonia.

[0039] Steam reforming of bioethanol can be carried out either autothermally or endothermally. In autothermal reforming, a portion of the bioethanol is combusted with the addition of air or oxygen, thus converting it into heat. However, this results in a lower specific hydrogen production than with endothermic reforming. Furthermore, a lower and therefore disadvantageous H2 / CO2 ratio is achieved. As a result, more specific bioethanol is produced than with endothermic reforming, and ultimately, more agricultural land is required to grow the bioproducts used for ethanol production. Therefore, endothermic reforming is preferred.

[0040] The thermodynamic conditions for synthesis gas production remain comparable to those currently used for natural gas, i.e., approximately 2 to 5 MPa pressure and temperatures between 500 and 1000 °C during reforming. Likewise, ammonia synthesis can continue in the usual way.

[0041] The ammonia is then combined with the previously separated CO2 in the downstream urea plant, which requires no modification, to produce the target product urea.

[0042] When using the process according to the invention in existing natural gas-fired plants, it is advisable to review the primary reformers for their continued usability. With the same plant capacity, as can be converted stoichiometrically, they would only be loaded with 70% of the previous volume flow and would also require less heat for the endothermic reforming. (Ethanol cracking enthalpy to methane cracking enthalpy = 28.9 / 41.2 kJ / mol H2). For gas separation, it should be considered that, due to the process and expressly desired, the amount of CO2 would be approximately 15% higher than before, with a higher concentration and a lower volume flow.

[0043] In order to operate an ammonia-urea complex fossil-free, not only in terms of the material aspects relevant to the invention, but also in terms of energy, appropriate solutions must be provided for the drives of motors, pumps, compressors, fans, and other power consumers, as well as for calorific tasks. The current state of the art, using renewable electricity and fossil-free energy sources, already offers practical solutions for this.

[0044] The ethanol used according to the invention undergoes the following conversion, summarized from reforming and conversion: C2H5OH + 3 H2O → 2 CO2 + 6 H2

[0045] This conversion theoretically produces twice as much hydrogen as is contained in ethanol, a reaction that also occurs in natural gas: CH4 + 2 H2O → CO2 + 4 H2

[0046] While this only results in a H2 / CO2 ratio of 4.0 for natural gas, which brings with it the disadvantages discussed earlier, surprisingly, ethanol achieves almost exactly the desired ratio of 3.0. Therefore, only a very slight CO2 excess is to be expected. Stoichiometric conversion of the above ethanol equation theoretically results in the following amounts of CO2 and H2: 974 Nm 3 CO2 / tonne of ethanol, 2923 Nm 3 H2 / ton of ethanol

[0047] According to current findings (14, 15, 16), an efficiency of up to 85% for hydrogen recovery in reforming can be expected, so that after CO conversion, a total H2 conversion of more than 90% can be assumed, even more so if there are further catalyst developments and a corresponding optimization of the operating parameters. If we assume 90% for the H2 conversion, then the real 2631 Nm 3 H2 / ton of ethanol. The corresponding production of 1.28 t of ammonia from this hydrogen results in 2.25 t urea / ton ethanol.

[0048] A urea plant with a capacity of 3,000 t / d, as exemplified several times previously, would therefore require only 445,000 t / a of bioethanol. By comparison, the methanol plant mentioned in (3) requires 260,000 t of wood or 800,000 t of sugar beet per year for a daily capacity of 300 t. Based on the data for bioethanol in Germany (17), only about 200,000 ha of agricultural land are required to produce the 445,000 t / a and the resulting 1,000,000 t / a of urea, or about 1.2% of Germany's 16.7 million ha of agricultural land (18).

[0049] While these explanations alone demonstrate the excellent suitability of bioethanol for a fossil-free ammonia-urea complex, further advantages emerge upon closer examination: If bioethanol is subjected to steam reforming as described, this not only requires the use of steam as a reactant, but it should also participate in the reaction in a superstoichiometric ratio, if possible. The reason for this is – much like in the steam reforming of natural gas – to create the desired reaction conditions and avoid carbon deposits in the reformer. For natural gas, the steam / carbon ratio (moles of water vapor / mole of carbon) serves as a measure, usually between 2.5 and 3.5. In (14), (15), and (16), the related term steam / ethanol ratio (moles of water vapor / mole of ethanol) is used. According to the studies, an optimal range is between 3 and 4, which corresponds to an ethanol concentration of between 39 and 46% by weight.

[0050] Instead of evaporating pure ethanol, the relatively complex production of which was discussed above, prior to reforming and separately adding the required water in liquid and / or vapor form to the process, it is significantly more effective to directly use a bioethanol-water mixture, as it arises during production. This can potentially significantly reduce the effort required for the concentration steps of distillation, rectification, and adsorption.

[0051] How practical this is depends on the distance from the supply plants to an ammonia-urea complex. In any case, the final dewatering step, a molecular sieve adsorption to overcome the azeotropic point, can be avoided. This step previously required enriching the mixture from approximately 95% to at least 99.7%. A significant further reduction in concentration effort is possible if the 10 to 14% ethanol-water mixture resulting from fermentation only needs to be subjected to a simple distillation, thereby increasing the alcohol content to approximately 40% in accordance with phase equilibrium—a concentration at which the mixture can be fed directly into the ammonia plant.

[0052] Given the significant advantages associated with the use of such aqueous alcohol mixtures, it is worthwhile to consider the construction of the necessary bioethanol capacities at or near an ammonia-urea complex for long-term planning purposes. Existing bioethanol plants in Germany already have capacities of up to 284,000 t / a (Südzucker Bioethanol GmbH), and a plant with a capacity of 395,000 t / a is even being planned (Abengoa Bioethanol plant in Rostock).

[0053] Bioethanol and urea plants at one location can lead to another advantage: In addition to bioethanol, equimolar CO2 is produced during the fermentative splitting of the starting material sugar: C6H 12 O6 → 2 C2H5OH + 2 CO2

[0054] This means that per ton of ethanol, 487 Nm 3 CO2. Assuming a 90% CO2 recovery, then 438 Nm 3CO2 for an additional 1.17 t urea / t ethanol, provided that importing ammonia beyond domestic production is possible and corresponding urea production capacity is available. However, even with available urea capacity, the size of the required ethanol plant can be minimized using the following algorithm: E = K / (2.25 + 1.17 = K / 3.42 E = t / a required bioethanol capacity, K = t / a available urea capacity

[0055] If we assume, as before, a 3000 t / d urea plant, the following picture emerges: 293,000 t / a required in-house production of bioethanol, from which 658,000 t / a urea from 375,000 t / a of own ammonia and 342,000 t / a urea from 195,000 t / a ammonia import Example 1

[0056] The explanation is based on Fig.1. To produce 125 t / h of urea, 58.5 t / h of 95% ethanol 2 together with 84.1 t / h of steam 4 are fed into a reformer and CO conversion unit 3. There, reforming takes place at a molar steam / ethanol ratio of 4.0 at 4 MPa and 800°C. Following this, after gradual cooling, the residual CO is converted into CO2 and hydrogen. The raw gas is then further cooled, and the remaining process steam is condensed and separated. In a gas separation unit 5, 146,200 Nm 3 / h hydrogen 8 and 46,900 Nm 3 / h CO2 7 is separated from the resulting raw synthesis gas and the remaining residual gas 6 is discharged as fuel gas. The hydrogen 8 is used together with 48,700 Nm 3 / h of nitrogen 10 from an air separation plant 9 is compressed to 16 MPa and converted in a conventional circulation system for ammonia synthesis 11 to 71.3 t / h of ammonia 12, which is separated by cooling, condensation, and separation. This ammonia, like the previously separated CO2 7, is compressed to 15 MPa and used to produce 125 t / h of urea in the urea plant 13. Example 2

[0057] The explanation is based on Fig. 2. Again, 125 t / h of urea are produced, but this time in a split form. 82.3 t / h of urea 14 are produced from 46.9 t / h of ammonia 12. Its production is technologically identical to that described in Example 1. Only the quantities differ: 91.5 t / h of 40% ethanol 2 from a bioethanol plant 1, 2.4 t / h of steam 4, 32070 Nm 3 / h nitrogen 10, 30,900 Nm 3 / h CO2 emissions 7 and 96,200 Nm 3 / h hydrogen 8. From the bioethanol plant 1, 16,000 Nm 3 / h CO2 15 is obtained. Together with an ammonia import of 24.4 t / h 16, after appropriate compression in the urea plant 13, a further 42.7 t / h of urea 17 are produced, so that a total of 125 t / h of urea 18 is produced as a product.

[0058] Advantages of the inventive use of bioethanol - Production of ammonia and urea without the use of fossil raw materials that cause CO2 emissions - Avoiding extremely high energy consumption and investing in the alternative of electrolytic production of hydrogen and CO2 separation from air - low raw material requirements due to high content of carbon and hydrogen in an almost ideal ratio for urea - new and also material use instead of the previous, foreseeably expiring, energetic use as a fuel additive for vehicles with combustion engines - energy-saving, as only partially required dehydration of the bioethanol - Avoiding the processing of very large organic masses at one location - good material properties for storage, transport, printing (1) Study on the question “Where will hydrogen come from in Germany by 2050?” Commissioned by the Federal Ministry of Transport, Building and Urban Development (BMVBS) and in coordination with the National Organisation for Hydrogen and Fuel Cell Technology (NOW), 8 / 2009 (2) Air Liquide Autothermal Reforming technology selected for first low-carbon hydrogen and ammonia production in Japan 2023, Paris, lecture (3) Road Map Chemistry 2050, Towards a greenhouse gas-neutral chemical industry in Germany, A study by DECHEMA and FutureCamp for the VCl, FutureCamp Climate GmbH, September 2019 (4) Study IndWEDe Industrialization of Water Electrolysis in Germany: Opportunities and challenges for sustainable hydrogen for transport, electricity and heat, NOW GmbH 2018 (5) Hydrogen Compass, Electrolysis in Germany: Performance, Objectives and Requirements until 2030 Berlin, 28 June 2022 (6) JR Salge, BJ Dryer, PJ Dauenhauer, LD Schmidt, Science 314, 801, (2006). (7) Development of an autothermal biogas reformer for the production of hydrogen, Florian Rau et al. 14th Symposium on Energy Innovation, 10 to 12 February 2016 Graz / Austria (8) Sustainable hydrogen production from vegetable oil and biodiesel, Martin, Stefan et al., Chemical Engineering Technology (8) p.1248 (9) Hydrogen from biomass, short study commissioned by the Federal Ministry of Food and Agriculture, Niels Dögnitz et al., 03 / 2022 (10) European Patent Office, Patent Knowledge News, 2022 (11) How efficient is direct air capture?, SCINEXX the knowledge magazine, May 26, 2023 (12) Simon Block and Peter Viebahn, ENERGY ECONOMIC NEWS 72nd year 2022 issue 4 Study on DAC with a lot of data for perspective 2045 (12) (13) Fuel cell systems based on renewable energy sources, Faculty of Energy, Process and Bioengineering, University of Stuttgart, dissertation by Heike Grüner, 2010 (14) Development of a bioethanol steam reformer for the production of hydrogen for use in a PEM fuel cell CHP plant, Dr. Rampe, Thomas, Dissertation, University of Duisburg-Essen, 2004 (15) Steam reforming of ethanol to provide synthesis gas for a solid oxide fuel cell range extender system, Bernhard Maunz, Institute of Chemical Engineering and Environmental Technology, Graz, October 2016 (16) Ethanol reforming for hydrogen production for fuel cells DISSERTATION by Dipl.-Ing. Gerd Rabenstein, Graz University of Technology, March 2010 (17) Federal Association of the German Bioethanol Industry, German Bioethanol Market Data (18) Industrieverband Agrar eV, Key Figures Fertilizers • Production • Market • Agriculture 2020

Claims

[1] Process for the production of ammonia and urea, characterized by that bioethanol or aqueous solutions of bioethanol 2, obtained by alcoholic fermentation, are subjected to an auto- or endothermic steam reforming and a subsequent CO conversion 3, hydrogen 8 and CO2 7, which are produced in this process, are obtained from the raw synthesis gas in a gas separation plant 5, from the hydrogen 8, together with a stoichiometric amount of nitrogen 10 from an air separation plant 9, ammonia 12 is then formed in a synthesis cycle system 11 and separated by cooling and condensation and finally this ammonia 12 is converted into urea 14 together with the previously separated CO2 7 in a downstream urea plant 13, wherein the CO2 15, which is produced during the bioethanol production, is separated and used for the production of further urea 17. [2] Method according to claim 1, characterized bythat bioethanol with a content of about 95% ethanol, and thus below its azeotropic point, is used [3] Method according to claim 1, characterized by that a bioethanol-water mixture with about 40% ethanol is used, as it is obtained after the distillative dehydration of bioethanol [4] Method according to claim 1 characterized by that only ammonia is produced

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