Sustainable production of isocyanate compounds and downstream products thereof

Abstract

A process and a system to produce sustainable, especially renewable diisocyanates as well as downstream products 5 thereof are provided.

Description

240953W0011Sustainable Production of Isocyanate Compounds and Downstream Products ThereofField of the InventionThis invention relates to a process and a system to produce isocyanate compounds as well as downstream products thereof.Background of the InventionFor decades, fossil carbon resources like coal, oil, and gas have been extensively used as the predominant raw material for energy production and petrochemical processes. This has led to an enormous increase of the carbon dioxide (CO2) concentration in the atmosphere causing global warming and climate change. In view of the finite availability of fossil resources and the urgency to reduce CO2 emissions, there is a high need to replace fossil carbon resources by renewable and recycled carbon resources and to use intermediates and products derived therefrom as efficiently as possible. Therefore, chemical production pathways with reduced carbon intensities are highly desirable, especially for chemical compounds manufactured in large volumes. In particular, chemical starting materials made from waste and biomass as well as chemical processes using sustainable energy sources and efficient recycling steps are becoming increasingly important for the transition to a more sustainable use of resources in the (petro-)chemical industry.Aromatic and aliphatic diisocyanates are key raw materials to produce commercially important polymers like polyurethanes and polyureas. Said polymers are formed by the addition polymerization of diisocyanates with polyols and polyamines, respectively. Polyurethanes are often used in the form of flexible or rigid foams, thermoplastic or thermoset elastomers, spandex-type elastomeric fibers, or in the formulation of coatings. Hence, routes to diisocyanates with a lower carbon footprint, in particular to aromatic diisocyanates, starting from sustainable C1 feedstocks like syngas or methanol are a highly attractive alternative to traditional processes, which rely predominantly on crude oil fractions as feeds.Summary of the InventionIn a first aspect, the present disclosure relates to a process to produce a diisocyanate, the process comprising the steps51) providing syngas;52) providing phosgene;53) providing methanol, preferably by converting at least a portion of said syngas to methanol, and converting at least a portion of said methanol to an unsaturated hydrocarbon, preferably selected from the group consisting of benzene, toluene, and propylene, more preferably to an aromatic hydrocarbon selected from the group consisting of benzene and toluene;54) converting at least a portion of said unsaturated hydrocarbon to a diamine; and55) reacting at least a portion of said diamine with at least a portion of said phosgene to obtain the diisocyanate; wherein optionally at least a portion of the phosgene of step S2) is provided from syngas of step S1).240953W0012In a second aspect, the present disclosure relates to a process to produce a diisocyanate, the process comprising the steps51) providing syngas;52) providing phosgene;S3*) converting at least a portion of said syngas to an unsaturated hydrocarbon, preferably selected from the group consisting of benzene, toluene, and propylene, more preferably to an aromatic hydrocarbon selected from the group consisting of benzene and toluene;54) converting at least a portion of said unsaturated hydrocarbon to a diamine; and55) reacting at least a portion of said diamine with at least a portion of said phosgene to obtain the diisocyanate; wherein optionally at least a portion of the phosgene of step S2) is provided from syngas of step S1).In a third aspect, the present disclosure relates to a system for producing an isocyanate compound, the system comprising the unitsU1) syngas providing unit;U2) phosgene providing unit;U3) unsaturated, preferably aromatic, hydrocarbon production unit;U4) diamine production unit; andU5) diisocyanate production unit.In another aspect, the present disclosure relates to the products manufactured by the processes or with the systems described herein, in particular to diisocyanates and downstream products derived therefrom with favorable and improved sustainability attributes, more specifically to such products with low carbon footprints, with net-zero or even net- negative carbon dioxide emissions.Further aspects of the present disclosure will become apparent to the person skilled in the art directly from the foregoing and following description.The sets of preferred embodiments described in the following for the different aspects of the invention are intended to further illustrate, but in no way to restrict the present invention as described herein. They represent a suitably structured part of the description and thus support, but do not represent the claims of the present invention.The sequence of process steps described herein does not require adherence to the specified order unless technical requirements dictate otherwise. Generally, the outlined process steps can be performed independently from one another, in any technically feasible sequence, or concurrently. Furthermore, intermediate steps may be integrated before, between, or after the indicated process steps, provided they do not disrupt the overall technical procedure or impede subsequent steps.240953W0013General Terms and DefinitionsThe term “sustainable”, as used herein, mainly refers to environmental sustainability. It relates to practices, actions, and attributes suited to maintain and preserve the health and balance of natural ecosystems and resources over the long term such that their capacities to regenerate are not exceeded, e.g., by minimizing resource depletion, pollution, waste production, and greenhouse gas emissions. When referring to resources and energy sources, the term “sustainable” includes, but is not limited to the terms renewable (e.g., derived from biomass, “bio-based”), recycled (e.g., derived from waste, “recycling-based”), and non-fossil (e.g., not derived from natural gas, oil, coal etc.).“Net-zero carbon dioxide emissions” refers to a situation in which anthropogenic carbon dioxide emissions (i.e., carbon dioxide emissions caused by human activities) are balanced by anthropogenic carbon dioxide removals (i.e., carbon dioxide withdrawals from the atmosphere as a result of deliberate human activities, e.g., using biological, technological, or geochemical methods, like enhancing biological sinks and using chemical engineering to achieve long-term removal and storage) over a specified period. “Net-negative carbon dioxide emissions” refers to a situation in which anthropogenic carbon dioxide removals exceed anthropogenic carbon dioxide emissions.The term “equipped to”, as used herein, means that a device, unit, or system has the necessary components, tools, mechanisms, features, or capabilities that enable it to carry out the specified operations, tasks, or functions and that it may be configured to do so.The term “fluidically connected to” in respect to at least two units means that a fluid can flow from one unit to the other, e.g., through a system of one or more pipes, e.g., driven by screw conveyors, extruders, or pumps.The terms “downstream of” and “upstream of”, respectively, refer to a relationship of at least two operations or units within a sequence of operations or units and designate a connection of said operations or units in or against the direction, respectively, of material streams passing said sequence.The terms “at least in part”, “at least a part of”, or “at least a portion of” refer to a fraction that is nonzero. It includes any fractions larger than 0 %, in particular it means a fraction of 10 %, preferably 20 %, more preferably 30 %, more preferably 40 %, more preferably 50 %, more preferably 60 %, more preferably 70 %, more preferably > 80 %, more preferably 90 %, most preferably 100 %.The terms “comprise(s)”, “comprising” etc. are inclusive of and may, in a preferred embodiment, be replaced by the terms “consist(s) of”, “consisting of” etc.The term “to provide” includes, but is not limited to the terms “to produce” and “to obtain”. Thus, e.g., steps of providing a substance or composition and units for providing a substance or composition are inclusive of and may, in a preferred embodiment, be replaced by steps of producing said substance or composition and units for producing said substance or composition.“Syngas” also known as “synthesis gas” refers to a mixture of predominantly CO and H2, which in addition may comprise minor amounts of CO2 and further components such as water and methane.“Biogas”, a mixture of mainly methane and carbon dioxide, may be obtained by anaerobic digestion of organic matter. As used herein, the term “biogas” includes pretreated and upgraded biogas. In the pretreatment step, water vapor as well as hydrogen sulfide, if present, are removed to obtain pretreated biogas. In the upgrading step, carbon dioxide is removed by absorption in water, by amines, by membranes, or the application of pressure swing adsorption to obtain240953W0014 upgraded biogas which is almost pure methane (bio-methane). Thus, “biogas” refers in particular to bio-methane. Details on said biogas-related processes are described for example in E.-J. Nyns et al., Ullmann's Encyclopedia of Industrial Chemistry, 2014, Chapter “Biogas”, and the references cited therein.“Biomass” is biological material derived from living or recently living organisms. In particular, the term “biomass” comprises plants or parts thereof like crops, energy crops, wood, wood waste, wood pellets, wood chips, forestry and agricultural residues, straw, lignocellulosic biomass, or residues thereof, marine organisms (like algae), biobased oils, biobased fats (preferably hydrated), and biowaste such as organic food waste.The term “waste” comprises fossil-based waste, biobased waste, and mixtures thereof. Examples for waste are agri- cultural / farming residues such as wood processing residues, waste wood, logging residues, switch grass, discarded seed corn, corn stover and other crop residues, municipal solid waste (MSW), industrial waste, hazardous waste, textiles, industrial waste, sewage sludge, (mixed) plastic waste, packaging waste, end-of-life tires, shredder residues such as automotive shredder residues, pyrolysis oils, and mixtures thereof.“Plastic waste” comprises polyalkenes, polystyrene, and copolymers thereof, polyvinylchloride (PVC), polyvinylidene chloride (PVDC), polyamides (PA), polyurethanes (PU), acrylonitrile butadiene styrene (ABS), polyesters, polycarbonate (PC), rubbers, caprolactam-based waste and mixtures thereof, preferably polyalkenes. Polyalkenes comprise polyethylene (LDPE, HDPE) and polypropylene. Plastic waste can be for example derived from automotive shredder residue, and / or mixed plastic waste. Also rubber waste is considered “plastic waste” in the sense of the present invention.The terms “fossil feedstock”, “fossil origin”, “fossil source” and the like include, but are not limited to coal, oil, natural gas, petcoke, carbonaceous products from crude oil refining, extra heavy crude oil, tar sand, bitumen, coke, high vacuum residues (HVRs), methane and mixtures thereof.“Sustainable energy” or “sustainable electrical power” comprises wind energy, solar energy (thermal, photovoltaic, and concentrated solar energy), hydropower (tidal power, wave power, hydroelectric dams, in-river-hydrokinetics), geothermal energy, ambient or industrial heat captured by heat pumps, bioenergy (biofuel, biomass), the renewable part of waste energy sources, and nuclear energy (fission), as well as combinations thereof.Brief Description of the DrawingsFIG 1 : Flow diagram showing a process to produce diisocyanate according to the first aspect of the invention.FIG 2: Flow diagram showing a process to produce diisocyanate according to the second aspect of the invention.FIG 3: Flow diagram showing a process to produce diisocyanate including the use of hydrogen from syngas.FIG 4: Flow diagram showing a process to produce diisocyanate including the use of chlorine from chlor-alkali electrolysis.FIG 5: Flow diagram showing a circular process including the production and recycling of diisocyanate-derived polymers.FIG 6: System for performing the processes according to FIGs 1-2FIG 7: System for performing the process according to FIG 3240953W0015Detailed Description of the InventionThe present invention provides a process and a system to produce isocyanate compounds as well as downstream products thereof.In particular, processes are disclosed that are suitable, even at large scale, for the formation of aromatic and aliphatic diisocyanates from C1 sources only. The processes allow for lower carbon footprints by incorporating non-fossil C1 sources, e.g., based on renewable and recycled feedstocks. Also, they may support the rise of a circular economy by facilitating the use of waste materials as feedstocks.Also, pathways are described that lead from one single C1 source like syngas to diisocyanates. Thus, logistics networks and supply chains are simplified since fewer different starting materials are required for the production network. This may not only provide economic advantages (e.g., fewer dependencies of different suppliers, more favorable contract terms, lower costs for storage and handling of different starting materials), but also facilitates the minimization or adjustment of the ecologic impact (e.g., the product carbon footprint contribution) of a product brought about by its starting materials. Further, insofar as the disclosure relates to processes involving direct syngas-to-aromatics conversions, energy consumption is expected to be reduced since fewer separation and / or purification steps of intermediate products are required; in addition, the overall production facility may be composed of fewer units such that investment costs, construction complexity, and maintenance efforts are reduced.The processes according to this disclosure are preferably carried out in a fashion that process steps are chosen which may be run with electrical energy, preferably of sustainable origin.The processes according to this disclosure start with the provision of syngas that preferably exhibits favorable sustainability attributes. In particular, favorable sustainability refers to limited net CO2 emissions, which can be achieved, e.g., by employing sustainable feedstocks, sustainable process schemes, sustainable energy sources, and / or by capturing and storing or utilizing CO2 formed in the course of the syngas production.From said syngas, carbon monoxide is separated that may be used to form phosgene in the presence of chlorine. On the other hand, said syngas (or alternatively methanol) may be converted to unsaturated (aromatic or olefinic) hydrocarbons, optionally via methanol as an intermediate, through syngas-to-aromatics, methanol-to-aromatics, methanol- to-olefins, and related processes. Said hydrocarbons are further transformed to diamines and reacted with phosgene to diisocyanates. Thus, all of the carbon atoms of the diisocyanate may originate from the syngas originally provided and may thus bear the favorable sustainability attributes.Said syngas may furthermore act as a source of hydrogen which may be employed in the formation of the above- mentioned diamines.It is also contemplated within the scope of this disclosure that the diisocyanates may be used as monomers in the formation of polymers like polyurethanes and polyureas. After the end of their lifespan such materials may be recycled and be a source of syngas, e.g., via gasification or pyrolysis processes.Thus, the present disclosure also provides diisocyanates and downstream products derived therefrom with favorable and improved sustain ability attributes, e.g., they are characterized by a low carbon footprint, in the case of bio-based feedstocks and long-lived products even by net-negative CO2 emissions.240953W0016Thus, in a first aspect, the present disclosure provides a process to produce a diisocyanate, the process comprising the steps51) providing syngas;52) providing phosgene;53) providing methanol, preferably by converting at least a portion of said syngas to methanol, and converting at least a portion of said methanol to an unsaturated hydrocarbon, preferably selected from the group consisting of benzene, toluene, and propylene, more preferably to an aromatic hydrocarbon selected from the group consisting of benzene and toluene;54) converting at least a portion of said unsaturated hydrocarbon to a diamine; and55) reacting at least a portion of said diamine with at least a portion of said phosgene to obtain the diisocyanate; wherein optionally at least a portion of the phosgene of step S2) is provided from syngas of step S1).Likewise, in the first aspect, the present disclosure relates to a process to produce a diisocyanate, the process comprising step S5)S5) reacting a diamine with phosgene to obtain the diisocyanate, whereby at least a portion of said diamine is provided from step S4)S4) converting an unsaturated hydrocarbon to a diamine; whereby at least a portion of said unsaturated hydrocarbon is provided from step S3)S3) providing methanol, preferably by converting at least a portion of said syngas to methanol, and converting at least a portion of said methanol to an unsaturated hydrocarbon, preferably selected from the group consisting of benzene, toluene, and propylene, more preferably to an aromatic hydrocarbon selected from the group consisting of benzene and toluene; and whereby at least a portion of said phosgene is provided from step S2)S2) providing phosgene; wherein optionally at least a portion of the phosgene of step S2) is provided from syngas of step S 1 )S1) providing syngas.In a second aspect, the present disclosure provides a process to produce a diisocyanate, the process comprising the steps51) providing syngas;52) providing phosgene;S3*) converting at least a portion of said syngas to an unsaturated hydrocarbon, preferably selected from the group consisting of benzene, toluene, and propylene, more preferably to an aromatic hydrocarbon selected from the group consisting of benzene and toluene;54) converting at least a portion of said unsaturated hydrocarbon to a diamine; and55) reacting at least a portion of said diamine with at least a portion of said phosgene to obtain the diisocyanate; wherein optionally at least a portion of the phosgene of step S2) is provided from syngas of step S1 ).240953W0017Likewise, in the second aspect, the present disclosure relates to a process to produce a diisocyanate, the process comprising step S5)S5) reacting a diamine with phosgene to obtain the diisocyanate, whereby at least a portion of said diamine is provided from step S4)S4) converting an unsaturated hydrocarbon to a diamine; whereby at least a portion of said unsaturated hydrocarbon is provided from step S3*)S3*) converting syngas to an unsaturated hydrocarbon, preferably selected from the group consisting of benzene, toluene, and propylene, more preferably to an aromatic hydrocarbon selected from the group consisting of benzene and toluene; whereby at least a portion of said syngas is provided from step S 1 )S1) providing syngas and whereby at least a portion of said phosgene is provided from step S2)S2) providing phosgene; whereby optionally at least a portion of said phosgene is provided from syngas of step S1 ).Preferred Embodiments1.1) The process according to the first aspect of the invention or according to the second aspect of the invention.Step S1)In step S1), syngas is provided in appropriate amounts, quality (e.g., purity), and H2-to-CO and H2-to-CO2 ratios, respectively, (together: H2-to-COx ratio) to facilitate the later further process steps, in particular steps S2), S3), and S3*).Providing syngas may include the substeps of producing syngas from a feedstock, purifying the raw syngas, and adjusting the H2-to-COx ratio in the (optionally purified) syngas. As a part of the last-mentioned substep, the coproduced CO2 may be captured from the resulting gas stream and preferably stored (carbon capture and storage, CCS) or utilized as a chemical feedstock (carbon capture and utilization, CCU) to avoid CO2 emissions to the atmosphere. Sustainable production pathways for syngas start, for instance, from waste or biomass and may include hydrogen and carbon oxides of sustainable origin.Producing Syngas from FeedstockSyngas may be produced from a plethora of carbon-containing feedstocks, virtually from any hydrocarbon feedstock, using a variety of technological approaches. In particular, syngas production may be accomplished by reaction of gaseous and liquid feedstocks with steam (steam reforming), CO2 (dry reforming), or 02 (partial oxidation) or by reaction of solid feedstocks with oxidants like 02 and / or steam (partial oxidation: gasification). Syngas may also be obtained from 002 and H2 as input materials via reverse water gas shift (reverse WGS, rWGS) reaction, in which CO and H20 are formed from 002 and H2. Furthermore, syngas mixtures in various compositions are accessible by co-electrolysis240953W0018 of CO2 and water. Syngas components H2 and CO may also be obtained by water electrolysis, chlor-alkali electrolysis, methane pyrolysis, or decomposition of ammonia and CO2 electrolysis, respectively.Traditionally, mainly fossil feedstocks like natural gas, naphtha, heavy vacuum residues, and coal have been used for the generation of syngas. Syngas production processes based on fossil feedstocks may be made more sustainable by capturing and storing the formed CO2 (e.g., as a by-product of complete oxidation and / or the WGS reaction) such that greenhouse gas emissions are limited. Nowadays, in view of the finite availability of fossil resources and the urgency to reduce net CO2 emissions, there is a high need to replace fossil carbon resources by sustainable, preferably renewable, carbon resources. Thus, non-fossil, sustainable sources of syngas have been attracting increasing interest. Thus, preferably, the provided syngas originates from bio-based or recycling-based carbon-containing feedstocks like biomass or waste that may be converted to syngas through processes like gasification, pyrolysis, and partial oxidation, or fermentation followed by steam reforming. Also, syngas may be obtained from CO2 and H2 through (partial) rWGS reaction, wherein, preferably, said CO2 had been captured from biomass or waste incineration, from other industrial processes, or from the atmosphere and said H2 had been produced sustainably, e.g., as described below, in particular by processes driven by renewable energy like water electrolysis. Further, syngas with reduced 002 emissions and thus a reduced carbon intensity may be generated by reforming of natural gas or gasification of coal wherein the formed 002 is captured and stored or used as a feedstock in the chemical industry. In particular, steam reforming, autothermal reforming, or dry reforming of biogas, gasification of biomass or waste, and rWGS reaction of 002 and H2 are contemplated within the scope of this disclosure as sustainable syngas sources.Reforming of Gaseous or Liquid FeedstocksReforming of hydrocarbons is a mature process to produce syngas. The main hydrocarbon reforming technologies are steam (methane) reforming (SMR), partial oxidation, and autothermal reforming (ATR) (the last-mentioned being basically a combination of the former two processes), all of which are well-known to the one of skill in the art. Said processes to produce syngas are described for example in H. Hiller et al., Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Gas Production, 1. Introduction”, R. Reimert et al., Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Gas Production, 2. Processes”, and the references cited therein.The most Important gaseous feedstock for reforming processes is methane, e.g., provided as natural gas, synthetic natural gas (SNG), or biogas. Also other low-boiling gaseous hydrocarbons like ethane or propane and liquid hydrocarbons, such as light naphtha cuts, can be reacted, e.g., after optional sulfur removal with water vapor via steam reforming.For instance, in steam reforming, methane (or other low-boiling hydrocarbons) is reacted with steam in the presence of a catalyst under high temperature and high-pressure conditions, whereas in partial oxidation, methane is reacted with sub-stoichiometric amounts of oxygen.Partial oxidation of hydrocarbons, in particular of natural gas, SNG, biogas, ethane and the like, may be carried out according to various routes. Among them is the partial combustion with oxygen or air to obtain acetylene along with a relatively carbon-rich syngas (e.g., Sachsse-Bartholome process). Said process is, for example, described in P. Passler et al., Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Acetylene”, and the references cited therein.240953W0019Another reforming approach uses CO2 as an oxidant (dry reforming), wherein methane and CO2 are converted in an endothermic reaction in the presence of a catalyst. Dry reforming is reviewed for example by D. Pakhare et al., Chem. Soc. Rev. 2014, 43, 7813-7837, Z. Alipour et al. Chem. Eng. J. 2023, 452, 139416, and the references cited therein.Gasification of Solid or Liquid FeedstocksGasification of solid or liquid feedstocks like fossil feedstocks (such as coal), biomass, waste, or mixtures thereof involves heating the feedstock to high temperatures in the presence of limited supplies of oxygen or steam. The conversion proceeds via thermal decomposition and subsequent heterogeneous reaction of the solid residue with reactive gases like 02, steam, CO2, or H2. Solid biomass feedstocks suitable for gasification include wood or residues thereof, (energy) crops or residues thereof, agricultural waste, and sewage sludge. Solid waste feedstocks suitable for gasification include municipal waste, hazardous waste, industrial waste, mixed plastic waste, caprolactam-based waste, or end-of-life tires. In particular, plastic waste comprising diisocyanate-derived polymers like polyurethanes, polyureas, polyamides, and polyimides are contemplated as a suitable feedstock within this disclosure.Syngas is for example produced from solid feedstocks via coal gasification. Coal is reacted thereby in a mixture of partial oxidation with air or pure 02 and gasification with water vapor to give a mixture of CO and H2. Via the Boudouard equilibrium carbon monoxide is in equilibrium with carbon and carbon dioxide.Furthermore, the WGS reaction must be taken into account. co + H2O co2+ H2,The exothermic reaction with oxygen provides the necessary energy to achieve the high reaction temperatures for the endothermic gasification reaction of carbon with water vapor.Also, more sustainable solid feedstocks like biomass (e.g., wood or straw) or waste may be converted to syngas through gasification techniques. These feedstocks may need to be pre-treated according to a suitable pre-treatment method or a suitable combination of pre-treatment methods with the aim to homogenize the physical and chemical properties of the feedstock, to meet certain requirements for a specific type of gasifier, and / or to meet certain requirements for further downstream process steps to produce chemical compounds.Suitable pre-treatment methods for a given feedstock are preferably selected from the group comprising drying, comminution, classification, sorting, agglomeration, chemical methods, and biological methods.Drying methods comprise belt drying, fluidized bed drying, drum drying, spray drying, hearth drying, rotary tray drying, and radiation drying.Comminution methods comprise pressure, impact, shearing, grinding, milling, shredding, crushing, and cutting. Grinding a feedstock may be carried out, e.g., in rod mills and ball mills, closed circuited with classification. Milling is preferably performed in a wet state. Accordingly, a grinding pre-treatment is preferably combined with a drying method in a single pre-treatment unit. Crushing may be performed in jaw-crushers, gyratory crushers, and cone crushers. Crushing is preferably performed in a dry state. Accordingly, a crushing pre-treatment is preferably combined with a drying method prior to crushing in a single pre-treatment unit.240953W00110Classification methods comprise screening (e.g., with revolving drum screens, surface screens, fixed and movable gratings), winnowing, flotation, zigzag classification, and air table classification. Screening systems preferably comprise one or more of bar screens, wedge wire screens, radial sieves, banana screens, multi-deck screens, vibratory screens, fine screens, flip flop screens, and wire mesh screens. Screens can be static, or they can incorporate mechanisms to shake or vibrate the screen(s).Sorting methods comprise manual sorting, pneumatic sorting, sensor-based sorting (e.g., NIR-assisted sorting, induc- tive-assisted sorting, and X-ray-assisted sorting), and metal separation (e.g., magnetic separation, eddy current separation).Agglomeration methods comprise pelletizing, briquetting, and extrusion. Such methods usually comprise a means for compressing the feedstock and optionally a further means for heating (“baking”) the compressed feedstock. Such pretreatment methods often provide better physical characteristics than the initial feedstock, improve the transportability of the feedstock, e.g., to another location, and improve the thermochemical behavior.Thermochemical methods comprise pyrolysis, converting the feedstock into char, and torrefaction. Thermochemical pre-treatment may be carried out in pyrolysis reactors in which the feedstock is heated to e.g., 500 °C in an inert atmosphere to obtain a pyrolysis oil having an improved calorific value compared to the untreated feedstock and a reduced volume which improves the transportability of the feedstock, e.g., to another facility.In particular, biomass is preferably torrefied or converted by pyrolysis into a pyrolysis oil prior to gasification.Municipal solid waste (MSW) is optionally pre-treated by methods such as drying, shredding, sorting, inert removal and may be used in the form of refuse-derived fuel (RDF).Biological methods comprise fermentation such as anaerobic fermentation.The gasification step is performed in a gasifier to produce raw syngas from the (optionally pre-treated) feedstock.The selection of reactor type and size depends on several parameters, including the composition of the carbonaceous feedstock, physical and / or chemical properties of the feedstock like water content, ash content, elemental composition, size, and calorific value, the demand of products, and the availability of the carbonaceous feedstock. It also depends on the pre-treatment method applied to the feedstock. An overview of gasifier types is for example provided in J. G. Speight, Handbook of Gasification Technology, Scrivener Publishing and Wiley, 2020, ch. 8.4.2, pp. 259-262. Preferably, the gasifier is selected from the group comprising counter-current fixed bed reactors, co-current-fixed bed reactors, bubbling fluidized bed reactors, circulating fluidized bed reactors, dual fluidized bed reactors, downdraft entrained flow reactors, updraft entrained flow reactors, and plasma gasifiers like fixed-bed plasma gasifiers, more preferably from the group comprising bubbling fluidized bed reactors, circulating fluidized bed reactors, dual fluidized bed reactors, downdraft entrained flow reactors, updraft entrained flow reactors, and fixed-bed plasma gasifiers.While gasifiers typically rely on heat generation by (partial) oxidation, in particular plasma gasifiers, e.g., their plasma torches, may be operated with electrical power, preferably sustainable electrical power.Preferred combinations of pre-treatment methods and gasifier types comprise:- screening and / or agglomeration with counter-current or co-current-fixed bed reactors;- crushing and / or shredding with bubbling, circulating, or dual fluidized bed reactors;- grinding with downdraft or updraft entrained flow reactors.240953W00111The gasification reaction in a gasifier is typically carried out at a temperature > 700 °C in the presence of a sub- stoichiometric amount of an oxidant such as 02, air, steam, supercritical water, CO2, or a mixture of the aforementioned. Oxygen is the most common oxidant used for gasification because of its easy availability and low cost. Preferably, the gasifier is an “oxygen blown" gasifier, i.e., 02 is preferably used as the oxidant in suitable gasifiers listed above. For example, the molar ratio “oxygen: oxygen required for a total oxidation of the feedstock” can range from 0.3 to less than 1 . It is particularly advantageous for any of the oxygen-consuming process steps described herein in terms of sustainability if as much of the needed 02 as possible is supplied with the help of renewable energy sources, e.g., via water electrolysis driven by renewable energy as described below. If steam acts as an oxidant, the raw syngas has a higher molar ratio H2-to-CO in comparison to the use of air as an oxidant. Gasification yields a raw syngas which has a i when leaving the gasifier which ranges from about 0.1 :1 to about 3:1 and depends on the type of solid and / or liquid feedstock used, the oxidant and other reaction conditions applied such as temperature and / or residence time of the reactants in the gasifier. A gasification reaction usually results in further reaction products such as solid and / or highly viscous carbonaceous residues (e.g., ash, char, and / or tar).Pyrolysis of Solid FeedstocksBiomass and waste, in particular plastic waste, may also be used to produce syngas via a pyrolysis reaction to obtain a pyrolysis oil and subsequent partial oxidation and / or gasification of said oil. Pyrolysis processes as such are known. They are described, e.g. for plastics, in EP 0713906 A1 , WO 95 / 03375 A1, and J. Woidasky, Ullmann’s Encyclopedia of Industrial Chemistry, 2020, Chapter “Plastics Recycling”, pp. 15-17, and e.g. for biomass in G. Wang et al., Energy Fuels 2020, 34, 12, 15557-15578. Pyrolysis oils are also commercially available.Typically, plastic waste comprises additives, such as processing aids, plasticizers, flame retardants, pigments, light stabilizers, lubricants, impact modifiers, antistatic agents, antioxidants, etc. These additives may comprise elements other than carbon and hydrogen. For example, bromine is mainly found in connection to flame retardants. Heavy metal compounds may be used as lightfast pigments and / or stabilizers in plastics. Cadmium, zinc, and lead may be present in heat stabilizers and slip agents used in plastics manufacturing. The plastic waste can also contain residues. Residues in the sense of the invention are contaminants adhering to the plastic waste. The additives and residues are usually present in an amount of less than 50 wt.-%, preferably less than 30 wt.-%, more preferably less than 20 wt.-%, even more preferably less than 10 wt.-%, based on the total weight of the dry weight plastic.Examples of rubber waste include end-of-life tires, rubber waste produced during manufacturing processes and discarded rubber containing products such as latex examining gloves and gaskets. End-of-life tires comprise further ingredients such as textiles and organic and inorganic additives which may be separated from the rubber portion of end- of-life tires prior to pyrolysis. Pyrolysis oils obtained by pyrolysis of (predominantly) end-of-life tires are also known as tire pyrolysis oils (TPO).Biomass waste like green waste, food waste, human waste, manure, sewage, sewage sludge and slaughterhouse waste may also be comprised and pyrolyzed.To obtain a plastic waste pyrolysis oil, the plastic waste is inserted into a pyrolysis reactor using a dosing unit such as a screw or an extruder or a rotary valve or a pneumatic conveyor or a liquid injector. The plastic waste is optionally pre-heated in e.g., a heat exchanger prior to insertion into the pyrolysis reactor and / or subjected to a pre-pyrolysis at240953W00112 a temperature in the range of, for example, from about 200 to about 360 °C. Next, the plastic waste is heated in the pyrolysis reactor to a temperature in the range of from about 350 to about 900 °C, more preferably in the range of from 400 to about 600 °C, and a pressure in the range of from about 0.5 to about 2 bar(abs), more preferably in the range of from 0.9 to about 1 .5 bar(abs). The pyrolysis reactor is preferably selected from the group comprising fluidized bed reactors, moving bed reactors, entrained flow reactors, screw reactors, extruders, stirred tank reactors and rotary kiln reactor. Preferably, the pyrolysis is performed in the pyrolysis reactor under an inert atmosphere exempt of 02 or air. Optionally, pyrolysis oils are subjected to an upgrading process. Said upgrading process is preferably selected from the group comprising washing, extraction, absorption, adsorption, distillation, hydrotreatment, catalytic cracking, catalytic aromatization, and combinations thereof. Such optional upgrading processes are for example described in WO 2021 / 224287 A1, WO 2023 / 061834 A1 , EP 0713906 A1, and WO 95 / 03375 A1 which are incorporated herein by reference. A skilled person knows how and in which cases to use upgrading processes disclosed in said documents and comparable upgrading processes disclosed elsewhere.Pyrolysis oils may be converted in a gasifier and / or partial oxidation reaction unit into syngas. Such gasifiers and partial oxidation reactions are known in the art and are for example disclosed in R. Reimert et al., Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter: “Gas Production, 2. Processes”, pp. 443-455, and J. G. Speight, Handbook of Gasification Technology, Scrivener Publishing and Wiley, 2020, and the references cited therein. The skilled person can select suitable reactors and reaction conditions to convert the pyrolysis oil into syngas by a partial oxidation reaction and / or gasification. Preferably, the pyrolysis oil is converted in an entrained-flow gasifier into syngas. rWGS of CO2 and H2CO2 may form the basis of syngas either by being used itself as the carbon-containing component of syngas (i.e., syngas consisting essentially of CO2 and H2) or by being converted with H2 to syngas consisting essentially of CO and H2 (e.g., through the rWGS reaction) or with CH4 of fossil or biobased origin (e.g., through dry reforming). rWGS reactions are described in Y. A. Daza et al., RSC Adv. 2016, 6, 49675-49691, E. Rezaei et al., Chemical Engineering Research and Design, 2019, 144, 354-369, EP2175986, CN103183346, US8946308, and the references cited therein. Preferably the CO2 and the H2 for said processes are of sustainable origin, more preferably the CO2 is captured from flue gases (most preferably derived from biomass) or the atmosphere and H2 is obtained with reduced or without CO2 emissions.- CO2 CaptureCO2 may be captured from the atmosphere (direct air capture, DAC), from the ocean (direct ocean capture, DOC; indirect ocean capture, IOC), or from industrial point sources of CO2 emissions (via pre-combustion capture, oxyfuel combustion, or post-combustion capture routes). Such industrial point sources include power plants based on combustion of organic material like coal, natural gas, biogas, oil, waste, or biomass (wood or residues thereof, (energy) crops or residues thereof, agricultural waste, sewage sludge) and industrial facilities like plants for cement production, steel manufacturing, chemical manufacturing, biogas production and processing, and refineries. In the area of chemical manufacturing, steam crackers, steam reformers (especially to produce hydrogen), partial oxidation plants (e.g., to obtain ethylene oxide, acetylene, or syngas), and facilities for the hydrotreatment of bio-oils or waste-derived pyrolysis240953W00113 oils are among the main facilities that emit significant amounts of CO2. Capturing CO2 is most cost-effective at point sources, such as large carbon-based energy facilities, industries with major CO2 emissions (e.g., cement production, steelmaking), natural gas processing, synthetic fuel plants, and fossil fuel-based hydrogen production plants. Extracting CO2 from air is possible, although the lower concentration of CO2 in air compared to combustion sources complicates the engineering and makes the process therefore more expensive. Thus, preferably, the CO2 is captured from industrial flue gases.Processes for capturing CO2 are described for examples in S. Topham et al., Ullmann's Encyclopedia of Industrial Chemistry, 2014, Chapter “Carbon dioxide”, and the references cited therein.In post combustion capture, the CO2is removed after combustion of the fossil fuel - this is the scheme that would apply to fossil-fuel power plants. CO2 is captured from flue gases at power stations or other point sources. Absorption or carbon scrubbing with amines is the dominant capture technology. It is the only carbon capture technology so far that has been used industrially. CO2 adsorbs to a MOF (metal-organic framework) through physisorption or chemisorption based on the porosity and selectivity of the MOF leaving behind a CO2 poor gas stream. The CO2 is then stripped off the MOF using temperature swing adsorption (TSA) or pressure swing adsorption (PSA) so the MOF can be reused. Similar processes may be applied to zeolites and other micro-porous materials.DAC is a process of capturing CO2 directly from the ambient air and generating a concentrated stream of CO2 for sequestration or utilization or production of carbon-neutral fuel. 002 removal is achieved when ambient air contact chemical media, typically an aqueous alkaline solvent or sorbents. These chemical media are subsequently stripped of 002 through the application of energy (namely heat), resulting in a 002 stream that can undergo dehydration and compression, while simultaneously regenerating the chemical media for reuse.Dilute 002 can be efficiently separated using an anionic exchange polymer resin called Marathon MSA, which absorbs air 002 when dry, and releases it when exposed to moisture. A large part of the energy for the process is supplied by the latent heat of phase change of water. Other substances which can be used are metal-organic frameworks (or MOF’s). Membrane separation of 002 rely on semi-permeable membranes.- H2 ProductionHydrogen, e.g., for use in the rWGS reaction or to adjust the H2-to-COx ratio of syngas as described below, may be obtained according to processes known in the art. Production process are for example described in P. Haussinger et al., Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Hydrogen, 2. Production” and the references cited therein. In particular, starting from natural gas, biogas, or other light hydrocarbons, steam reforming, autothermal reforming, or other syngas-producing processes (especially if followed by a WGS reaction and hydrogen separation) and pyrolysis of hydrocarbons provide substantial amounts of H2. Further important H2 production technologies comprise water electrolysis and chlor-alkali electrolysis as well as H2 generation by decomposition of H2 carriers like ammonia. H2 with favorable sustainability attributes may be obtained by separation from syngas with favorable sustainability attributes according to gas separation processes known in the art, e.g., as described in P. Haussinger et al., Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Hydrogen, 2. Production”, Chapter “Hydrogen, 3. Purification”, and the references cited therein, in particular by pressure-swing adsorption. Said syngas may be produced according to any of the above-mentioned syngas-producing processes starting from sustainable, i.e., renewable or recycled,240953W00114 feedstocks. H2 with favorable sustainability attributes may be produced also from fossil sources, e.g., via steam reforming or autothermal reforming of natural gas, when the formed CO2 is captured and stored. Alternatively, it may be obtained through methane pyrolysis of natural gas, synthetic natural gas, or biogas, wherein solid carbon, but no CO2 is formed as a by-product. Sustainable H2 may also be manufactured by electrolysis of water and chlor-alkali electrolysis in which at least a part of the needed electrical power is generated from non-fossil, renewable sources.In methane pyrolysis (also referred to as “methane decomposition”), light hydrocarbons, in particular methane, e.g., in the form of natural gas or biogas, is decomposed without the involvement of oxygen into H2 and solid, high-purity carbon (e.g., as carbon black, carbon powder, or granular carbon). In contrast to reforming, however, no gaseous CO2 is produced, but solid carbon is formed as a by-product, which has a positive effect on economic efficiency and ecologic impact. Further, compared to water electrolysis, methane pyrolysis requires significantly less energy. Therefore, methane pyrolysis is considered a promising sustainable technology for future hydrogen production.Methane pyrolysis may be carried out in different ways known to the one skilled in the art (Muradov et al., International Journal Hydrogen Energy 2008, 33, 6804-6839; Abbas et al., International Journal Hydrogen Energy 2010, 35, 1160- 1190); Dagle et al.: An Overview of Natural Gas Conversion Technologies for Co-Production of Hydrogen and Value- Added Solid Carbon Products, Report by Argonne National Laboratory and Pacific Northwest National Laboratory (ANL-17 / 11 , PNNL-26726, November 2017): catalytically or thermally, and with heat input via plasma, microwave, heated carrier gas, resistance heating, induction, liquid metal processes, or autothermally, in particular via plasma pyrolysis (WO 2015 / 116797, WO 2015 / 116800), metal melting / metal salt melting (WO 2020 / 161192, WO 2021 / 183959), moving bed process (US 2982622, WO 2019 / 145279, WO 2020 / 200522, WO 2023 / 057242), (fluidized bed) catalytic process (WO 2011 / 029144, WO 2016 / 154666), or partial / pulsed combustion (WO 2020 / 118417 and US 2022 / 0185664), the moving bed process being particularly advantageous due to its high efficiency, heat integration, flexibility, and favorable product carbon footprint. These processes differ i.a. in the form of the energy used (thermal, electrical, etc.), the process conditions (temperature, pressure, etc.), the catalysts, and / or auxiliary materials used. The pyrolysis process is preferably heated electrically, even more preferably by resistive heating (Joule heating) of the substrate material (US 2982622, WO 2019 / 145279, and WO 2020 / 200522).The solid carbon type generated in the methane decomposition depends on the reaction conditions, reactor, and heating technology. Examples are carbon black from plasma processes carbon powder from liquid metal processes granular carbon from thermal decomposition in fixed, moving, or fluidized bed reactors.The processing and separation of solid carbon depends on the chosen pyrolysis technology and is known by the person skilled in the art. Thus, solid carbon may be separated by a cyclone or a filter and may be post-treated, e.g., to achieve agglomeration; further, the carbon may be purified by washing and / or evaporation techniques to remove, for instance, residual metal contamination. The resulting gas stream comprising hydrogen may be finally purified by a PSA process to remove remaining impurities like hydrogen sulfide, carbon oxides, hydrocarbons, and inert gases like nitrogen, to yield purified hydrogen.240953W00115Electrolysis of water is an environmentally friendly method to produce hydrogen because it may use H2O as a sustainable resource and produces only pure 02 as by-product. Within the present invention, said 02 may be used advantageously in oxygen-consuming processes like partial oxidation, autothermal reforming, gasification, ammonia oxidation, or methanol oxidation as described herein. Additionally, water electrolysis utilizes direct current (DC), preferably from sustainable energy sources, for example solar, wind, hydropower, and biomass.One suitable water electrolysis process is alkaline water electrolysis. Hydrogen production by alkaline water electrolysis is a well-established technology up to the megawatt range for a commercial level. Alkaline electrolysis operates at lower temperatures such as 30-80°C with alkaline aqueous solution (KOH / NaOH) as the electrolyte, the concentration of the electrolyte being about 20% to 30 %. However, alkaline electrolysis has negative aspects such as limited current densities (below 400 mA / cm2), low operating pressure and low energy efficiency.Polymer electrolyte membrane (PEM) water electrolysis was developed to overcome the drawbacks of alkaline water electrolysis. Variants of PEM water electrolysis are proton exchange membrane water electrolysis (PEMWE) and anion exchange membrane water electrolysis (AEMWE). PEM water electrolysis technology is similar to the PEM fuel cell technology, where solid polysulfonated membranes (Nation®, fumapem®) are used as an electrolyte (proton conductor). These proton exchange membranes have many advantages such as low gas permeability, high proton conductivity (0.1 ± 0.02 S cm-1), low thickness (20-300 pm), and allow high-pressure operation. In terms of sustainability and environmental impact, PEM water electrolysis is one of the most favorable methods for conversion of sustainable energy to highly pure hydrogen. PEM water electrolysis has great advantages such as compact design, high current density (above 2 A cm-2), high efficiency, fast response, operation at low temperatures (20-80°C) and production of ultrapure hydrogen. The state-of-the-art electrocatalysts for PEM water electrolysis are highly active noble metals such as Pt / Pd for the hydrogen evolution reaction (HER) at the cathode and I1O2 / RUO2 for the oxygen evolution reaction (OER) at the anode.One of the largest advantages of PEM water electrolysis is its ability to operate at high current densities. This can result in reduced operational costs, especially for systems coupled with very dynamic energy sources such as wind and solar power, where sudden spikes in energy output would otherwise result in uncaptured energy. The polymer electrolyte allows the PEM water electrolyzer to operate with a very thin membrane (ca. 100-200 pm) while still allowing high operation pressure, resulting in low ohmic losses, primarily caused by the conduction of protons across the membrane (0.1 S / cm), and a compressed hydrogen output.An overview of hydrogen production by PEM water electrolysis is given in S. Kumar and V. Himabindu, Material Science for Energy Technologies 2 (2019), pp. 4442 - 4454. An overview of hydrogen production by anion exchange membrane water electrolysis is given in H. A. Miller et al., Sustainable Energy Fuels, 2020, 4, pp. 2114 - 2133.Hydrogen may be furthermore obtained by the chlor-alkali electrolysis process which is known to the one of skill in the art. The process is for example described in P. Schmittinger et al., Ullmann's Encyclopedia of Industrial Chemistry, 2011 , Chapter “Chlorine”, pp. 538-595, and the references cited therein.240953W00116Also, generation of H2 by decomposition of ammonia is contemplated within the scope of this invention. Such processes are known to the one of skill in the art and have been reviewed, e.g., by I. Lucentini et al., Ind. Eng. Chem. Res. 2021, 60, 51 , 18560-18611.Within the present disclosure, the production of hydrogen is preferably not associated with CO2 emissions from fossil sources. Thus, preferred processes are steam reforming, autothermal reforming, and other syngas-producing processes in which the formed by-product carbon dioxide is captured and sequestered or used as a chemical raw material and is thus not released to the atmosphere. Further preferred processes are steam reforming, autothermal reforming, and other syngas-producing processes based on renewable resources like biogas or other biomass-derived light hydrocarbons. Even more preferred processes are those with net-negative CO2 emissions, e.g., steam reforming, autothermal reforming, and other syngas-producing processes based on renewable resources and combined with CCS or CCU, or methane pyrolysis based on renewable resources like biogas or other biomass-derived light hydrocarbons. Other preferred processes to produce H2 are electrolysis of water and chlor-alkali electrolysis in which at least a part of the needed electrical power is generated from non-fossil, renewable sources. The term “at least in part” means that another part of the electrical power can still be produced from fossil fuels (preferably from natural gas, since combustion of natural gas causes much lower carbon dioxide emission per Megajoule of electrical energy produced than combustion of coal). However, the portion of electrical energy produced from fossil fuels should be as low as possible, preferably s 50%, more preferably s 30%, most preferably s 20%, further most preferably s 10%, ideally < 1 %. Preferably, the electrical power is at least in part, preferably exclusively, sustainable energy, as defined hereinbefore.Various methods for certification and tracking of the “energy source mix” have been set up based on local legislations, e.g., Guarantees of Origin (Gos: Europe), Renewable Electricity Cerficates (RECs: USA, Canada), or international RECs (l-RECs: China, India, Brazil, Mexico, Indonesia, South Africa, etc). Certificates such as “Non-Fossil Certificate Contracts” are common practice for tracking the ratio of non-fossil energy used in industrial processes and related products (e.g., https: / / www.ekoenergy.org / ecolabel / criteria / tracking / ).Co-electrolysis of CO2 and waterReversible solid oxide cells (rSOCs) working in solid oxide electrolysis cell (SOEC) modality can provide syngas from CO2 and water. Such processes are, e.g., reviewed in A. Hauch et al., Science 2020, 370, eaba6118.The SOEC technology is a promising method for syngas generation due to its high efficiency and flexibility. SOECs operate at elevated temperatures, which enhances the thermodynamics and kinetics of the electrolysis process, allowing for the direct conversion of water (in the form of steam) and CO2 into syngas. Significant advancements have been made in the performance and durability of SOECs, making them more viable for industrial applications. Additionally, SOECs use abundant raw materials and scalable production methods, which contribute to their potential for large- scale deployment and cost-effectiveness.The SOEC technology can be thermally integrated with various chemical synthesis processes. Advantageously, the composition of the syngas produced by SOECs can be adjusted by varying the input ratios of steam and CO2: By increasing the proportion of steam relative to CO2, the hydrogen content in the syngas increases, and vice versa. Additionally, operating conditions such as temperature and current density can also influence the syngas composition.240953W00117CO2 electrolysisCO for use as a syngas component, e.g., in admixture with syngas from any of the above-mentioned processes or in admixture with hydrogen from any of the above-mentioned processes, may be obtained from CO2 by electrochemical reduction. In particular, CO may be produced, optionally along with oxygen, by electrolysis of CO2 or CO2-enriched air, especially using SOECs, e.g., as described by A. Hauch et al., Science 2020, 370, eaba6118. Said CO2 electrolysis may be carried out as a high-temperature electrolysis at more than 600 °C. Such processes are known in the art, e.g., the commercially available Haldor Topsoe process (C. Mittal et al., Chemical Engineering World 2017, 44-46). For low- temperature CO2 electrolysis at below 150 °C, gas diffusion electrodes (e.g., as described by T. Haas et. al., Nature Catalysis 2018, 1 , 32-39) or membrane-electrode-assemblies (e.g., as described by L. Ge et al., Chem 2022, 8, 663— 692) may be employed.Purification of SyngasThe raw syngas obtained by any one or more of the processes described hereinbefore may be further treated to obtain purified syngas.In such purification steps, impurities and other undesired components are removed. Typical impurities in the raw syngas, e.g., as obtained from gasification processes, comprise acid gases, halogen, e.g., chlorides, sulfur-containing organic compounds such as sulfur dioxide, ammonia, amines, trace heavy metals like mercury (e.g., as respective salts), tars / condensable hydrocarbons, and particulate residues like dust. Various chemical and / or physical methods for removal of such impurities from said raw syngas such as filtration, scrubbing, condensation and ab- / adsorption are known and can be chosen and adapted according to the type and respective concentration of the impurities in said raw syngas and the tolerance to such impurities in the successive process steps. E.g., bulk particulate impurities can be removed from the raw syngas by a cyclone and / or filters, fine particles, ammonia, and chlorides by wet scrubbing, trace heavy metals by solid absorbents, and sulfur-containing organic compounds (e.g., COS) by catalytic hydrolysis to H2S and acid gas removal. Bulky and fine particles such as dust in the syngas may also be removed with a quench in a soot water washing unit.Purification of raw syngas is preferred to improve the lifetimes and to maintain the activities of catalysts utilized in successive process steps and to meet environmental emission regulations.Adjusting the H2-to-COx ratioTo facilitate the further syngas use, it will be typically necessary to adjust the H2-to-COx ratio in the obtained syngas to fulfill the stoichiometric requirements for the subsequent CO- and syngas-utilizing processes like S2), S3), and S3*). These are typically described by the stoichiometric number S, defines as S = ([H2]-[CO2]) / ([CO2]+[CO]). For instance, SMR may provide a stoichiometric number of approximately 2.8 while biomass gasification may deliver syngas with a stoichiometric number of only slightly above 1. To produce methanol, the ratio of carbon oxides to hydrogen in the synthesis gas is adjusted to meet the reaction equationsCO + 2 H2 — > CH3OHCO2 + 3 H2 ^ CH3OH + H2O240953W00118Thus, a H2-to-CO molar ratio of approximately 2 will be needed for methanol production and even higher values in case the syngas comprises substantial amounts of CO2 that have to be converted. A stoichiometric number of slightly above 2 has been proven to be optimal. Such adjustment may be achieved, for instance, by carrying out the WGS reaction or by admixing H2 and CO2, respectively, from external sources, i.e., from processes other than those to produce said syngas, e.g., from water electrolysis or carbon capture.The WGS equilibrium allows to adjust the stoichiometric number according to the following reaction equation:CO + H2O H2 + CO2Thus, the H2 content in the syngas is increased by reacting at least a portion of the CO comprised in the raw syngas with water to form additional H2 and CO2 and thereby a H2-enriched syngas stream is generated. Hence, CO-rich syngas can be H2-enriched or CO-depleted via the WGS reaction by adding water and removing CO2. I.e., syngas having a first molar ratio H2-to-CO is converted in the WGS reaction to a H2-enriched syngas having a second molar ratio H2-to-CO, wherein said second molar ratio is larger than said first molar ratio.The WGS reaction is an exothermic reaction. It is preferably performed according to processes known in the art, such as those defined in W.-H. Chen, et al, Applied energy 2020, 258, 114078. It can be conducted with a variety of catalysts (such as copper-zinc-aluminum catalysts and chromium or copper promoted iron-based catalysts) in the temperature range between about 200 °C and about 480 °C. The type of WGS reaction can be adapted to the general conditions and requirements of the process, e.g., how much additional H2 obtained by the WGS reaction is desired.Vice versa, the rWGS reaction, starting from H2-rich syngas, yields H2-depleted or CO-enriched syngas by adding CO2 and removing water.Details on the WGS equilibrium are described, e.g., in H. Hiller et al., Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Gas Production, 1. Introduction” and R. Reimert et al., Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Gas Production, 2. Processes”, and the references cited therein.CO2 formed in step S1), during the syngas production process and / or the WGS reaction, may be removed at least in part from syngas. A variety of processes to capture CO2 is available to the one of skill in the art; suitable methods for CO2removal from syngas include membrane separation, cryogenic separation, absorption, adsorption, e.g., with PSA or MOFs, and combinations thereof. In particular, CO2 may be removed from the syngas by absorption. The syngas is contacted with an aqueous solution of alkylamines such as monoethanolamine, diethanolamine, methyldiethanolamine and the like or methanol (“amine wash” or “methanol wash”). CO2 is captured in such solutions / liquids in a chemical reaction and then directed to a “regenerator” (e.g., a stripper with a boiler) where the absorption reaction is reversed such that CO2 and the recovered alkylamine are obtained.Processes for the separation and storage of carbon dioxide are described, e.g., in Topham et al., Ullmann's Encyclopedia of Industrial Chemistry, 2014, Chapter “Carbon Dioxide”, pp. 1-43, and the references cited therein.As an alternative or addition to the WGS reaction, H2 and CO2, respectively, from external, preferably non-fossil sources may be admixed to the syngas to adjust the H2-to-COx ratio according to the needs of the overall process and to allow for a maximum conversion of carbon oxides to downstream chemicals. Said external sources of H2 and CO2 are described above and include water electrolysis and methane pyrolysis to produce H2 and carbon capture to produce CO2.240953W00119In that sense CO2 from different bio-based sources can be included into the syngas. The biogenic source of CO2 could be from fermentation processes of biomass, combustion processes of biomass or waste of biobased materials, or from extractive processes of atmospheric CO2. Of course, mixtures of CO2 from biogenic and fossil carbon sources can be used, too.Preferred Embodiments1 .2) The process according to any of the preceding embodiments, wherein in step S 1 ), said syngas comprises CO and H2.1 .3) The process according to any of the preceding embodiments, wherein in step S 1 ), said syngas comprises CO2 and H2.1 .4) The process according to any of the preceding embodiments, wherein in step S 1 ), said syngas comprises CO, CO2, and H2.1.5) The process according to any of the preceding embodiments, wherein step S1) comprises producing syngas comprising CO and / or CO2 and comprising H2 and wherein step S1) preferably comprises purifying said syngas.1.6) The process according to embodiment 1.5, wherein step S1) further comprises adjusting the stoichiometric number by carrying out the WGS reaction and / or by addition of H2, and optionally of CO2, from external sources.1 .7) The process according to any of the preceding embodiments, wherein in step S 1 ), said syngas has a stoichiometric number in the range from 1 .9 to 3.0, preferably in the range from 2.0 to 2.5, more preferably in the range from 2.0 to 2.2, most preferably of approximately 2.1 or approximately 2.2.1 .8) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from a sustainable production process, preferably comprising carbon capture and / or using renewable energies.1 .9) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said CO and / or of said CO2 originates from sustainable sources, preferably from bio-based or recycling-based carbon-containing feedstocks.1.10) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said H2 originates from sustainable sources, preferably from water electrolysis, chlor-alkali electrolysis, methane pyrolysis, or decomposition of ammonia.1.11) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from steam reforming or autothermal reforming of at least one gaseous and / or liquid feedstock, preferably selected from the group consisting of methane, biogas, ethane, propane, light naphtha cuts, and biomass-derived light hydrocarbons, more preferably at least a portion of said syngas originates from steam reforming or autothermal reforming of methane, optionally followed by water-gas shift reaction, wherein CO2 that is formed in the steam reforming or autothermal reforming process and / or in the water-gas shift reaction is captured and optionally stored and / or utilized.240953W001201.12) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from partial oxidation or autothermal reforming of at least one gaseous and / or liquid feedstock, preferably selected from the group consisting of methane, biogas, ethane, propane, light naphtha cuts, and biomass-derived light hydrocarbons, wherein preferably said partial oxidation or autothermal reforming is carried out in the presence of oxygen at least a portion of which is provided from water electrolysis, more preferably from water electrolysis driven by renewable energies.1.13) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from dry reforming of at least one gaseous feedstock, preferably of methane or biogas, and CO2, wherein preferably at least a portion of said CO2 is obtained via DAC, DOC, and / or IOC or is obtained via carbon capture from industrial point sources.1.14) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from gasification, optionally after a pre-treatment step, of at least one solid and / or liquid feedstock, preferably comprising biomass and / or waste, preferably of plastic waste comprising diisocyanate-derived polymers, e.g., as obtained by step S6), like polyurethanes, polyureas, polyamides, or polyimides, in particular polyurethanes, wherein preferably said gasification is carried out in the presence of oxygen at least a portion of which is provided from water electrolysis, more preferably from water electrolysis driven by renewable energies.1.15) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from pyrolysis of at least one solid feedstock, preferably comprising biomass, more preferably selected from the group consisting of wood or residues thereof, crops or residues thereof, agricultural waste, and sewage sludge, and / or waste, more preferably selected from the group consisting of municipal waste, hazardous waste, industrial waste, mixed plastic waste, caprolactam- based waste, and end-of-life tires, most preferably plastic waste comprising diisocyanate-derived polymers, e.g., as obtained by step S6), like polyurethanes, polyureas, polyamides, or polyimides, in particular polyurethanes, to obtain a pyrolysis oil, and subsequent partial oxidation and / or gasification of said pyrolysis oil, wherein preferably said partial oxidation and / or gasification is carried out in the presence of oxygen at least a portion of which is provided from water electrolysis, more preferably from water electrolysis driven by renewable energies.1.16) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from rWGS reaction of CO2 and H2, wherein preferably at least a portion of said CO2 originates from biomass and / or is obtained via DAC, DOC, and / or IOC or is obtained via carbon capture from industrial point sources and / or wherein preferably at least a portion of said H2 originates from water electrolysis, chlor-alkali electrolysis, methane pyrolysis, decomposition of ammonia, or syngas production processes the CO2 emissions of which are captured and optionally stored and / or utilized.1.17) The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from co-electrolysis of CO2 and water or from CO2 electrolysis, e.g.,240953W00121 using a SOEC, wherein preferably at least a portion of said CO2 originates from biomass and / or is obtained via DAC, DOC, and / or IOC or is obtained via carbon capture from industrial point sources.1.18) The process according to any of embodiments 1.10 and 1.16 to 1.17, wherein in step S1), electrical power is used for said water electrolysis, chlor-alkali electrolysis, methane pyrolysis, co-electrolysis of CO2 and water, and / or CO2 electrolysis and the fraction of said electrical power that originates from fossil energy sources is < 50%, preferably s 30%, more preferably s 20%, even more preferably s 10%, most preferably < 1 %.1.19) The process according to any of embodiments 1.10 and 1.16 to 1.18, wherein in step S1), electrical power is used for said water electrolysis, chlor-alkali electrolysis, methane pyrolysis, co-electrolysis of CO2 and water, and / or CO2 electrolysis and at least a part, preferably all, of said electrical power originates from non-fossil energy sources, preferably selected from the group consisting of wind energy, solar energy, hydropower, geothermal energy, ambient or industrial heat captured by heat pumps, bioenergy (biofuel, biomass), the renewable part of waste energy sources, or nuclear energy.Step S2)In step S2), phosgene is provided in sufficient amounts and quality (e.g., purity) for further use as described below, in particular for step S5). While said phosgene may in principle originate from any conceivable source that is known to the one of skill in the art, phosgene is preferably produced from carbon monoxide and chlorine, wherein more preferably said carbon monoxide originates at least in part from syngas, e.g., as provided in step S1 ), preferably as described hereinafter. Thus, at least a portion of said phosgene preferably exhibits favorable sustainability properties, for instance, it originates from sustainable, e.g., bio-based or recycling-based sources or it has a reduced product carbon footprint.In particular, phosgene may be obtained by separating carbon monoxide from the syngas provided in step S1) followed by reacting said carbon monoxide with chlorine.Separation of Carbon Monoxide from SyngasCarbon monoxide may be obtained from syngas, e.g., as provided in step S1 ), by subjecting the (optionally purified) syngas stream to cryogenic separation, e.g., in a cold box to obtain at least one gas stream consisting essentially of carbon monoxide. Alternatively, pressure swing adsorption techniques may be applied. In particular, carbon monoxide for phosgene production should be substantially free of hydrogen, water, methane, and sulfur compounds. Such carbon monoxide separation techniques are known in the art and are disclosed , e.g., in J. Bierhals, Ullmann’s Encyclopedia of Industrial Chemistry (2012), Chapter “Carbon Monoxide”, pp. 685-687, and the references cited therein.Also, said carbon monoxide for phosgene production may be blended or used interchangeably with carbon monoxide from other, preferably sustainable sources.Providing ChlorineChlorine for the production of phosgene may be obtained by electrochemical processes like chlor-alkali electrolysis or hydrochloric acid electrolysis as well as by catalytic oxidation of hydrogen chloride. These processes are for example240953W00122 described in P. Schmittinger et al., Ullmann's Encyclopedia of Industrial Chemistry, 2011 , Chapter “Chlorine”, pp. 538-595, and the references cited therein.The chlor-alkali electrolysis process which is a well-established industrial process is known to the one of skill in the art: An aqueous solution of sodium chloride is decomposed by using direct current to deliver chlorine, hydrogen, and sodium hydroxide solution. The so-called diaphragm cell process, the mercury cell process, and the membrane cell process may be used.The electrolytic decomposition of aqueous hydrochloric acid, e.g., in a diaphragm cell process or a membrane cell process, yields chlorine and hydrogen. Also, electrolytic processes using gas diffusion electrodes, e.g., oxygen-consuming gas diffusion electrodes, e.g., oxygen depolarized cathodes (ODC), may be used (see, for instance, US 6,022,634, WO 2003 / 031690).Alternatively, chlorine may be generated by the catalytic oxidation of hydrogen chloride with air or oxygen (known as Deacon process, see, e.g., WO 2012 / 025483). Said oxygen originates preferably from water electrolysis. Suitable catalysts are mainly metal oxides and / or metal chlorides, e.g., based on copper, chromium, or ruthenium, on various substrates. Commercial processes are known as KEL chlorine process (using cone, sulfuric acid with nitrosylsulfuric acid as a catalyst), Shell chlorine process (using a mixture of copper(ll) chloride and other metallic chlorides on a silicate carrier as a catalyst), and Mitsui MT-Chlorine process (using a chromium(lll) oxide catalyst on a silicate carrier). Preferably, at least a portion of the hydrogen chloride and hydrochloric acid, respectively, needed for the chlorine production, is generated from the hydrogen chloride which is obtained as a side product of the isocyanate production described hereinafter in step S5). Also, hydrogen chloride may be obtained from recycling of chlorine-containing polymers, e.g., by pyrolysis or other chemical degradation processes. Preferably, at least a part of the electrical power needed for the above-mentioned electrolysis steps, e.g., the chlor-alkali electrolysis or the hydrochloric acid electrolysis, is generated from non-fossil, renewable sources.Phosgene ProductionPhosgene is produced from carbon monoxide and gaseous chlorine. Said process is known to the one of skill in the art and described, for example, in L. Cotarca et al., Ullmann's Encyclopedia of Industrial Chemistry, 2019, Chapter “Phosgene”, and the references cited therein.Phosgene synthesis is typically carried out at elevated temperatures and pressures up to 10 bar using activated carbon as a catalyst. Multitubular reactors made of carbon steel or stainless steel are employed which are filled with the catalyst.Preferred Embodiments1 .20) The process according to any of the preceding embodiments, wherein in step S2), at least a portion of said phosgene is provided by reaction of carbon monoxide with chlorine.1.21) The process according to the preceding embodiment, wherein in step S2), at least a portion of said carbon monoxide is provided by separation from syngas, preferably from syngas of step S1 ).1 .22) The process according to the preceding embodiment, wherein in step S2), said separation is carried out by cryogenic separation or by pressure swing adsorption, preferably by cryogenic separation.240953W001231 .23) The process according to any of embodiments 1.20 to 1.22, wherein in step S2), at least a portion of said chlorine is obtained by chlor-alkali electrolysis, preferably according to a diaphragm cell process, to a mercury cell process, or to a membrane cell process.1 .24) The process according to any of embodiments 1.20 to 1.23, wherein in step S2), at least a portion of said chlorine is obtained by hydrochloric acid electrolysis, preferably according to a diaphragm cell process, to a membrane cell process, or to electrolytic processes using gas diffusion electrodes.1 .25) The process according to any of embodiments 1.20 to 1.24, wherein in step S2), at least a portion of said chlorine is obtained by catalytic oxidation of hydrogen chloride with air or oxygen, said oxygen being obtained preferably by water electrolysis.1 .26) The process according to any of embodiments 1 .24 to 1 .25, wherein in step S2), at least a portion of said hydrochloric acid and hydrogen chloride, respectively, is provided from an isocyanate production step, preferably from step S5).1 .27) The process according to any of embodiments 1 .24 to 1 .26, wherein in step S2), at least a portion of said hydrochloric acid and hydrogen chloride, respectively, is provided from a recycling process of a chlorine-containing polymer, the recycling process preferably comprising a pyrolysis step.1 .28) The process according to any of embodiments 1.23 to 1 .25, wherein in step S2), at least one of said electrolysis steps is driven at least in part by renewable energy.Step S3)In step S3), methanol is provided in sufficient amounts and quality (e.g., purity) for further use in chemical processes, in particular for the conversion to unsaturated hydrocarbons or formaldehyde. While said methanol may in principle originate from any conceivable source that is known to the one of skill in the art, methanol may in particular be produced from syngas, e.g., as provided in step S1), preferably as described hereinafter for substep S3b). Preferably, at least a portion of said methanol exhibits favorable sustainability properties, for instance, it originates from sustainable, in particular bio-based or recycling-based sources or it has a reduced product carbon footprint.Of note, methanol may also be provided in its dehydrated form as dimethyl ether (DME). Thus, whenever methanol is mentioned in the following as a material to be provided or to be produced, the term methanol is meant to include DME.Substep S3a)In substep S3a), syngas is provided in appropriate amounts, quality (e.g., purity), and H2-to-CO and H2-to-CO2 ratios, respectively, (together: H2-to-COx ratio) to facilitate substep S3b).The above description of step S 1 ), including all of its embodiments, shall apply equally to substep S3a).Of note, S1) and S3a) may be identical or independent of each other, i.e., S1 ) and S3a) may be carried out as one single process or as separate, independent processes. Hence, S 1 ) and S3a) refer to the same process or to different processes. Preferably, S1) and S3a) are carried out as one single process starting from the same feedstock, i.e., substep S3b) is carried out with syngas provided according to step S 1 ).240953W00124Substep S3b)The conversion of syngas to methanol, as described by substep S3b), is well-known in the art. Details on the methanol synthesis and various options thereof suitable to be combined with the processes described herein are disclosed, e.g., in Ott et al., Ullmann's Encyclopedia of Industrial Chemistry (2012), Chapter “Methanol”, p. 3 to 13, and the references cited therein.In particular, methanol may be produced from syngas by a catalytic gas phase reaction in a low-pressure process at about 5-10 MPa and about 200-300 °C, e.g., in adiabatic reactors or quasi-isothermal reactors. The catalyst is for example a mixture of copper and zinc oxides on alumina support or an indium-based catalyst. Typically, a stoichiometric number of slightly above 2 has proven beneficial to achieve high conversion rates.Alternatively, methanol may be formed directly by reaction of CO2 and H2 in the presence of a catalyst. Overviews on the reaction and suitable catalyst systems are given, e.g., by M. Ren et al., Catalysts 2022, 12, 403 and K. Stangeland et al., Energ. Ecol. Environ. 2020, 5, 272-285.Also, a process for the CO2-to-methanol synthesis can be carried out, for example, by the method known from DE-A- 42 20 865, which produces methanol under the influence of silent electrical discharges. Alternatively, 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).Typical catalysts are described, for example, by N. Kanoun et al., Catalysis Letters 1992, 15, 231-235. Potential catalysts like CuO / ZnO and Cu-ZnO-AI2O3 are also described by R. M. Navarro et al., Materials 2019, 12, 3902 and by S. G. Jadhav et al., Chem. Eng. Res. Des. 2014, 92 2557-2567.Promising catalyst systems for large-scale industrial processes are Cu-based and In-based due to their superior catalytic performance. Recently a high selective catalysts ln2O3 / ZrO2 was described for industrial relevant conditions. A typical range of industrially relevant conditions for the hydrogenation of CO2 to methanol are T = 200-300°C, p = IQ- 50 MPa, and gas hourly space velocity (GHSV) of 16000-48000 h-1 (O. Martin et al., Angew. Chem. Int. Ed. 2016, 55, 6261 -6265).The conversion can be carried out in the presence of a copper-zinc-alumina catalyst. If copper-zinc-alumina catalysts are employed, the preferred temperature is in the range of from 150 to 300°C, preferably 175 to 300°C, and the preferred pressure is in the range of from 10 to 150 bar (abs).The synthesis of methanol from CO2 is less exothermic than that starting from syngas, and it also involves as a secondary reaction the rWGS reaction. To facilitate methanol synthesis, the CO in syngas is converted to CO2 through the WGS reaction:CO2 + 3 H2 CH3OH + H2O AH(298K) = -49.5 kJ mol-1CO2 + H2 CO + H2O AH(298K) = 41 .2 kJ mol-1The water-gas equilibrium mentioned above provides the basis to produce CO2-neutral methanol if the CO2 originates from appropriate direct or indirect biogenic sources. According to the rWGS reaction, there is the opportunity of including biogenic CO2 directly to an adapted syngas-to-methanol process. Syngas is then converted to methanol, e.g., in the ranges of temperature of 250-300°C and pressure of 5-10 MPa, using CuO / ZnO / AI2O3 catalyst.240953W00125Substep S3c)Step S3) further comprises the conversion of at least a portion of the provided methanol to an unsaturated hydrocarbon (substep S3c)), preferably selected from benzene, toluene, and propylene. This may be achieved by processes known as methanol-to-aromatics (MTA) and methanol-to-olefins (MTO), respectively.Methanol-to-AromaticsThe conversion of methanol to aromatics, particularly to benzene or toluene, can follow several routes that will be discussed below. The most prominent option to convert methanol into aromatics is through the so-called MTA process, which applies shape-selective zeolites as typical catalysts.The reaction of converting methanol to aromatics takes place through a hydrocarbon pool type of mechanism (ACS Catal. 2021 , 11 , 13, 7780-7819), This mechanism involves an indirect C-C bond formation. Both methanol and the dehydrated version, dimethyl ether (DME), can be used as starting materials for this process. Thus, whenever methanol is mentioned in the following as a starting material for the conversion to aromatics, the term methanol is meant to include DME.The catalyst used for this reaction is a shape-selective zeolite-based catalyst. Various types of zeolitic materials can be employed for this transformation, but the most commonly used catalysts are based on zeolites with pore size geometries between 9 and 12 membered-rings (MRs) (molecular sieves). Specifically, zeolites with 10 MR pores, such as MFI zeolites (also known as ZSM-5 type catalysts) or MEL zeolites, are widely used. Other relevant 9 to 12 MR pore zeolites are AEL.AFI, AFO, AFR, AFS, AFY, BEC, BOG, BPH, CAN, CON, EMT, EON, EOS, FAU, FER, GME, IFW, IMF, ITH, ITR, STT, IWR, LTL, MAZ, MOR, MSE, MWW, BEA, OFF, SAF, SVR, TON and intergrowth structures. The zeolite catalyst can be modified in several ways. One approach is to control the Si / AI ratio, which refers to the chemical composition of the zeolite framework. The number and strength of acid sites can also be controlled. Additionally, other elements, such as alkaline earth metals or lanthanides, can be added to modify the acidic properties of the catalyst. Furthermore, metals like zinc (Zn) and gallium (Ga) can be introduced to provide a dehydrogenating function. The zeolite catalyst is typically used in the form of shaped catalytic bodies or formulated powders, depending on the specific process employed.The MTA process produces mainly polyalkylated products, but also relevant amounts of monoaromatics such as benzene and toluene. The yields of these products may be increased by post-treatment processes. The main MTA processes are described hereinafter in more detail.• Fluidized bed MTATo address the issue of fast catalyst deactivation, a fluidized bed type reactor is employed for the aromatization of methanol or DME. This reactor configuration offers several advantages in terms of catalyst performance and product selectivity. It is thus preferred compared to the fixed bed process described below. The setup can consist of a single reactor, although it is preferred to have additional reactors to allow for partial conversions per reactor step or upgrading of the by-products, i.e., increasing the yield of the desired main product by converting or suppressing the formation of by-products. This approach helps in maintaining a higher selectivity towards aromatic products.240953W00126To further optimize the process, an intermediate product separation step can be optionally conducted. This allows for the separation of desired aromatic compounds from other non-aromatic by-products, such as linear alkenes and alkanes. Additionally, the recycling of MeOH / DME can be performed, which not only helps in increasing the overall yields of aromatics but also minimizes the consumption of these valuable feedstocks.Periodic catalyst regeneration is preferably a part of the process to maintain the desired performance. This involves the removal of deactivated catalyst and the introduction of fresh catalyst. The frequency of catalyst regeneration depends on various factors, including the specific catalyst used and the operating conditions.The reaction is carried out at elevated temperatures, typically above 350°C, with a preferred range between 400°C and 550°C. The pressure during the process typically ranges from 0.05 MPa to 3 MPa.To optimize product separation, several concepts can be employed. It should be noted that the aromatic product mainly consists of polyalkylated aromatics, particularly xylenes and methylated benzenes. Since current MTA processes primarily focus on p-xylene production, modifications of this MTA process are advantageous to increase the benzene yield. Such a process involves separating the benzene and toluene from the product stream, instead of recycling them in the process. Additionally, a hydrodealkylation unit should be considered to further enhance the benzene yield.The methanol feedstock is introduced into the first reactor, R1 , which is the methanol aromatization reactor. The effluent mixture from R1 is sent to a first separation unit: Unconverted methanol and recovered light fractions from R1 may be forwarded into a second aromatization reactor, R2, which operates under similar conditions as R1 in terms of temperature (400-650°C) and pressure. In some instances, the temperature in R2 may be higher than in R1. However, the catalyst used in R2 may differ from the catalyst used in R1 , e.g., in terms of metal content or metal type, and may have slightly different properties, such as an increased dehydrogenation functionality, e.g., brought about by the presence of transition metals with increased dehydrogenation activity. Thus, the second reactor R2 may also be used for the aromatization of light paraffins.The effluent stream from R2 is mixed with the converted fractions of the effluent stream of R1 and the combined stream is sent to a second separation unit. It is generally preferred to cool down the feed and allow the stream to separate into three phases: water, organic, and gas. The water phase is removed at the bottoms and discharged from the system. The organic phase is sent to an aromatics separation unit, while the gas phase is liquefied for further separation. The separated light fraction (e.g., C1-4 alkanes) is then recycled back into the process (either in R1 or R2, both are possible).The hydrogen produced during the process can be further separated and purified for external use, or burned in the process for energy recovery to supply the energy needed for the aromatization reactions.In the aromatics separation section, the non-aromatic compounds are separated and recycled back to at least one of the aromatization reactors for further conversion. The benzene and toluene components are separated and purified, while the xylenes and other polyalkylated aromatics are directed to a hydrodealkylation unit.In the hydrodealkylation reactor, the polyalkylated aromatics undergo a process known as hydrodealkylation, which involves the removal of alkyl groups from the aromatic compounds. After this step, the benzene is separated from the process stream, while the lights (light fractions) are recycled back into the aromatization process.240953W00127This process may operate with methanol conversions above 99%, indicating that the vast majority of methanol is converted into aromatic compounds. The yield of benzene could range between 13-20%. The exact yield would depend on various factors, including the catalyst used, operating conditions, and the specific design of the process.• Fixed bed MTAThe fixed bed MTA process can be considered as an alternative for directly converting methanol to aromatics.To address the challenge of catalyst deactivation in a fixed bed process, several approaches can be implemented. One option is to use a series of fixed bed reactors, where each reactor allows for partial conversion of methanol. By having multiple reactors in series, the conversion can be distributed among them, thereby reducing the overall deactivation rate and extending the catalyst lifespan.Another approach is the use of a moving bed reactor. In this configuration, fresh catalyst is continuously dosed into the reactor, while the deactivated catalyst is simultaneously removed and sent for regeneration. The moving bed reactor allows for a continuous supply of active catalyst, mitigating the issue of catalyst deactivation and enabling sustained performance.Both the series of fixed bed reactors and the moving bed reactor offer potential solutions to overcome the catalyst deactivation observed in fixed bed MTA processes. The choice between these options would depend on various factors, including the specific requirements of the process, the availability of catalyst regeneration facilities, and the desired level of conversion and selectivity.The catalyst is based on a zeolite, preferably similar to the fluidized bed MFI or MEL material, but other 9-12 MR pore zeolite can be used as well. In the fixed bed MTA process, the catalyst takes on a different form compared to the fluidized bed process. In this case, the catalyst is shaped into extrudates, spheres, or tablets using an inorganic binder, e.g., based on AI2O3, SiO2, TiO2, or ZrO2. This shaping process helps to create a more structured catalyst bed, allowing for better control and optimization of the reaction conditions. The acidity, hydrophobicity and dehydrogenation functions are designed specifically for this application: control of Si / AI composition, the dopants type (e.g., transition metals, alkali metals, or alkaline earth metals), possibility of surface modification (e.g., silylation), and addition of transitional metals (like zinc, gallium).The work-up section in the fixed bed MTA process is similar to that of the fluidized bed process, including the recycling concept for light by-products like C1-4 alkanes. The light hydrocarbons are directed to a separate unit, where an aromatization reactor for light hydrocarbons is built and operated.This separate unit operates using an aromatization catalyst based on a zeolitic material, preferably an MFI aluminosilicate doped with Ga. Also, other metals like Zn and Mo as well as mixtures, especially binary mixtures, of the aforementioned metals can be employed as dopants. Further, promoters such as alkali metals, alkaline earth metals, or lanthanides may comprised in the catalytic system. This catalyst system is specifically designed to promote the aromatization of light hydrocarbons into aromatic products. By using a separate reactor for light aromatization, it is possible to optimize the process conditions and enhance the selectivity towards desired aromatic products.The work-up section in the fixed bed MTA process may be advantageous for the overall efficiency of the process. By effectively separating and recycling the light fractions, it is possible to minimize waste and enhance the overall yield of240953W00128 desired aromatic products. The use of a separate unit for light aromatization helps to further optimize the process and improve its overall performance.• Other routes for MTAMethanol may also be converted to aromatics following a catalyst relay concept (T. Li et al., https: / / doi.org / 10.21203 / rs.3.rs-2827106 / v1 ), i.e., a reaction sequence in which two or more distinct catalysts or multifunctional catalysts are employed to facilitate a series of bond-forming transformations. Here, a bifunctional catalytic system (mix of a dehydrogenation catalyst (mixed metal oxide) with an aromatization catalyst based on zeolitic material, e.g., ZnO and ZnZSM-5) enables the conversion of methanol to formaldehyde and light olefins which subsequently undergo Prins- and Diels-Alder reactions to produce monoaromatics. Thus, the above-mentioned hydrocarbon pool is circumvented. This process may provide increased yields and selectivities towards monoaromatics, in particular to BTX while reducing catalyst deactivation.Since the catalyst deactivation is significantly lower, a fixed bed process can be used with a reduced amount of reactors and lower recycling streams. Recycling of the light hydrocarbons (mainly ethylene and propylene) into the aromatization reactor may further enhance the performance. The work-up section otherwise is similar in terms of unit operations as for the fluidized bed MTA process• Indirect methanol-to-hydrocarbons processesBTX (Benzene, Toluene, Xylene) fractions can indeed be obtained as side products in certain methanol-to-hydrocar- bons (MTH) reactions. Two well-known commercial examples of these processes are Methanol-to-Olefins (MTO) and Methanol-to-Propylene (MTP). Both MTO and MTP processes convert methanol, DME, and mixtures thereof into olefins, mainly ethylene and propylene, respectively, and as by-products, they can also generate BTX fractions.MTO and MTP processes are known in the art and described, e.g., in P. Tian et al., ACS Catal. 2015, 5, 1922-1938; M. Khanmohammadi et al., Chin. J. Catal. 2016, 37, 325-39; and M. A. Ali et al., Catalysis Letters 2019, 149, 3395- 3424.The MTO process is predominantly carried out in fluidized bed reactors, while the MTP process is typically conducted in fixed bed reactors. Both processes utilize zeolite catalysts, which play a crucial role in the conversion of methanol or DME into olefins. These catalysts are designed to selectively promote the desired reactions, leading to the production of olefins as the main product. However, as a side effect of these reactions, BTX fractions can also be formed. Another process that can generate BTX as a by-product is the Synthetic Alcohols to Fuels (SAF) process. In the SAF process, methanol or DME is converted into longer hydrocarbon chains, known as oligomers, which can be used as fuels or aviation fuels. Similar to MTO and MTP, zeolite catalysts are used in the SAF process, and modified versions of the MTO / MTP processes are often employed.Preferred Embodiments1 .29) The process according to any of the preceding embodiments, wherein in step S3) at least a portion of said methanol originates from bio-based or recycling-based sources.240953W001291 .30) The process according to any of the preceding embodiments, wherein step S3) comprises producing methanol, preferably wherein at least a portion of said methanol is provided from syngas of step S1 ).1.31) The process according to any of the preceding embodiments, wherein in step S3), providing methanol comprises the substepsS3a) providing syngas; andS3b) converting at least a portion of said syngas to methanol.1 .32) The process according to any of the preceding embodiments, wherein in step S3), providing methanol comprises the substepsS 1 ) providing syngas; andS3b) converting at least a portion of said syngas to methanol.1 .33) The process according to any of embodiments 1 .31 to 1 .32, wherein in substep S3b), said conversion is carried out in the presence of a copper-zinc-alumina-based catalyst, e.g., CuO / ZnO / AI2O3.1 .34) The process according to any of embodiments 1.31 to 1 .32, wherein in substep S3b), said conversion is carried out in the presence of an indium-based catalyst, e.g., I n2O3 / ZrO2.1 .35) The process according to any of the preceding embodiments, wherein in step S3), said methanol comprises dimethyl ether and / or said methanol is provided in admixture with dimethyl ether.1 .36) The process according to any of the preceding embodiments, wherein in step S3), said conversion to an unsaturated hydrocarbon comprises a methanol-to-aromatics step.1 .37) The process according to embodiment 1.36, wherein in step S3), said methanol-to-aromatics step is a fluidized bed process step, preferably using a zeolite catalyst in the form of shaped catalytic bodies or formulated powders.1 .38) The process according to embodiment 1.36, wherein in step S3), said methanol-to-aromatics step is a fixed bed process step, e.g., carried out in a moving bed reactor, preferably using a zeolite catalyst shaped into extrudates, spheres, or tablets using an inorganic binder.1 .39) The process according to any of embodiments 1.36 to 1.38, wherein in step S3), said conversion comprises the separation of light by-products and their aromatization, preferably using a zeolitic catalyst, more preferably an MFI aluminosilicate doped with Ga, Zn, Mo, or binary mixtures thereof, optionally further comprising a promoter.1 .40) The process according to any of embodiments 1 .36 to 1 .39, wherein in step S3), said methanol-to-aromatics step is carried out in the presence of a shape-selective zeolite-based catalyst, preferably of a shape-selective zeolite catalyst with 9 to 12 MR pores such as MFI or MEL zeolites.1 .41) The process according to embodiment 1 .36, wherein in step S3), said methanol-to-aromatics step is a catalytic process, preferably in a fixed bed, to form formaldehyde and light olefins as intermediates and to convert these intermediates into aromatics, using a bifunctional catalytic system comprising dehydrogenation and aromatization catalysts.1.42) The process according to embodiment 1.36, wherein in step S3), said methanol-to-aromatics step is part of a methanol-to-olefins process step or a methanol-to-propylene process step or an alcohols-to-fuels process step, e.g., carried out in a fluidized bed reactor, preferably using zeolite catalysts.240953W001301 .43) The process according to any of embodiments 1 .36 to 1 .42, wherein in step S3), said methanol-to-aromatics process step comprises partial conversions in more than one reactor.1 .44) The process according to any of embodiments 1 .36 to 1 .43, wherein in step S3), said methanol-to-aromatics process step is carried out at a temperature above 350 °C and a pressure of 0.05 MPa to 3 MPa.1 .45) The process according to any of embodiments 1 .36 to 1 .44, wherein in step S3), said conversion comprises a post-treatment process step and / or an aromatics separation step.1 .46) The process according to any of embodiments 1 .36 to 1 .45, wherein in step S3), said conversion comprises at least one process step selected from the group consisting of upgrading of by-products, intermediate product separation, methanol recycling, hydrogen recovery, catalyst regeneration, and hydrodealkylation of alkylated aromatics.1 .47) The process according to any of the preceding embodiments, preferably according to any of embodiments 1.36 to 1 .46, wherein in step S3), said unsaturated hydrocarbon is an aromatic hydrocarbon, preferably selected from the group consisting of benzene and toluene.1 .48) The process according to any of the preceding embodiments, wherein in step S3), said conversion to an unsaturated hydrocarbon comprises a methanol-to-olefins process step or a methanol-to-propylene process step.1 .49) The process according to embodiment 1 .48, wherein in step S3), said methanol-to-olefins process is a fluidized bed process step, preferably using a zeolite catalyst.1 .50) The process according to embodiment 1 .48, wherein in step S3), said methanol-to-propylene process is a fixed bed process step, preferably using a zeolite catalyst.1.51) The process according to any of the preceding embodiments, preferably according to any of embodiments 1.48 to 1.50, wherein in step S3), said unsaturated hydrocarbon is an olefinic hydrocarbon, preferably it is propylene.Step S3*)Syngas, as a starting raw material, is an attractive feedstock due to its ability to be produced from various, preferably sustainable sources as described hereinbefore for step S1). The process of converting syngas into aromatics is known to the one of skill in the art (e.g., from C. D. Chang, A. J. Silvestri, Journal of Catalysis 1977, 47, 249_259; EP20141 A1 (1980)).The syngas-to-aromatics process generally involves the combination of mixed metal oxide catalysts responsible for activating the syngas, e.g., modified methanol catalysts like ZnCrOx-type or ZnGaOx-type catalysts, mixtures of copper and zinc oxides on alumina support or indium-based catalysts, and a zeolite material that converts the formed intermediate into aromatics. Both catalysts are used in the same chemical reactor without any intermediate separation or purification of the chemical species. By properly controlling the active catalytic site distances and reactivity, key reaction intermediates are formed on the mixed metal oxide catalyst and then transferred to the aromatization catalytic function. The main advantages of this process are that, through proper design, side reactions can be avoided by directly converting the key intermediates into aromatics, resulting in higher yields of aromatic products. Additionally, milder conditions can be achieved, and there is a saving in terms of intermediate separation (capital expenditure and energy). Moreover, CO2 can be used as a co-reactant, and CO2 / H2 raw materials can be used as a starting feedstock.The main concepts for the syngas to aromatics process are described hereinafter:240953W00131• OxZeo conceptIn this concept (Jiao et al., Science, 2016, 351 , 1066 - 1068; Jiao et al., Angew. Chem. Int. Ed., 2018, 57, 4692; Yang et al., Chem. Commun, 2017, 53, 11146), a mixed metal oxide catalyst is obtained through the modification of a methanol type catalyst (ZnCrOx-type or ZnGaOx-type catalysts, mixtures of copper and zinc oxides on alumina support or indium-based catalysts, as well as different spinel-type materials) and is combined with a zeolitic material. If a 10 MR pore zeolite is used, aromatics can be formed. To enhance the yield of aromatics, plate-type MFI zeolites are utilized, which suppress the directional growth over the b-direction, resulting in short length straight channels.This design choice leads to aromatics selectivities close to 70% (based on non-CO2 hydrocarbon products), although primarily trimethylbenzenes are formed. To increase the production of benzene and toluene, a hydrodealkylation process step is advantageous, as discussed in the process concept from MTA reaction.The OxZeo process employs a fixed bed reactor with a mixed catalyst bed. The syngas used in this process has compositions of CO:H2 ranging from 1 :1 to 1 :2, and the reaction temperature is around 380 °C. Additionally, CO2 can be co-dosed during the process.Since CO2 is co-formed in the process, the first step of product separation requires the separation of CO2 from the lights / hydrocarbon products and recycling of this CO2.• Fischer-Tropsch-to-aromaticsAnother version of the syngas to aromatics process involves the combination of a modified Fischer-Tropsch catalyst, which has reduced activity and suppresses chain growth, and a zeolite catalyst. It is described, e.g., in J. L. Weber et al., Catal. Sci. Technol. 2024, 14, 4799. Similar to the OxZeo process, this reaction takes place in the same reactor, with proper control of the spacing between the two catalytic functions.In this process, the syngas activation occurs on the mixed metal oxide catalyst, which is typically a modified Co-Fischer Tropsch type catalyst or an Fe-type catalyst. This leads to the formation of CxHy intermediates, which are then converted into hydrocarbons by the zeolite catalysts. The selectivity towards aromatics is approximately 60% in terms of non-CO2 products, and polyalkylated aromatics are the main products. To increase the yield of benzene / toluene, post hydrodealkylation is advantageous.• Methanol intermediate routesAnother version of the syngas to aromatics process involves the mixing of a methanol (ZnZr or CuZn MMO's) type catalyst with a zeolite material. It is described, e.g., in P. Zhang et al., Chem. Sci. 2017, 8, 7941 and X. Yang et al., Chin. J. Catal. 2020, 41(4), 561-573. In this process, methanol is formed as an intermediate and immediately converted by the zeolite function. This process is similar to the MTA route, with the exception that a stand-alone methanol plant is skipped. Furthermore, the thermodynamics of methanol synthesis can be enhanced by continuous conversion to hydrocarbons, resulting in a higher syngas per pass conversion compared to methanol synthesis alone.Similar to the MTA process, a work-up section is envisaged, while the reaction takes place in a fixed-bed type reactor. Advantageously, CO2can be dosed into the reactor feed. To increase the benzene / toluene selectivity, the incorporation of a hydrodealkylation step is preferred.240953W00132Preferred Embodiments1 .52) The process according to any of the preceding embodiments, wherein in step S3*), said conversion to an unsaturated hydrocarbon comprises a syngas-to-aromatics step.1 .53) The process according to any of the preceding embodiments, wherein in step S3*), said conversion is carried out in the presence of a bifunctional catalytic system comprising a syngas activating catalyst, preferably selected from mixed metal oxides, and an aromatization catalyst, preferably selected from zeolites.1 .54) The process according to any of the preceding embodiments, wherein in step S3*), said conversion is carried out in a fixed bed reactor.1 .55) The process according to any of the preceding embodiments, wherein in step S3*), said conversion is carried out in the presence of a bifunctional catalytic system comprising a mixed metal oxide catalyst, e.g., a zinc- chromium-oxide based catalyst, and a zeolite-based catalyst, preferably a 10 MR pore zeolite, more preferably a plate-type MFI zeolite.1 .56) The process according to any of the preceding embodiments, wherein in step S3*), said syngas has a molar ratio H2-to-CO in the range from 1 :1 to 2:1 , and optionally comprises carbon dioxide.1 .57) The process according to any of the preceding embodiments, wherein step S3*) is carried out at a temperature of 350 °C to 420 °C, preferably at around 380 °C.1 .58) The process according to any of the preceding embodiments, wherein in step S3*), during said conversion Fischer-Tropsch-type hydrocarbons are formed as intermediates.1 .59) The process according to embodiment 1.58, wherein in step S3*), said conversion is carried out in the presence of a bifunctional catalytic system comprising a cobalt- or iron-based catalyst and a zeolite-based catalyst.1 .60) The process according to any of the preceding embodiments, wherein in step S3*), during said conversion methanol is formed as an intermediate.1.61) The process according to embodiment 1.60, wherein in step S3*), said conversion is carried out in the presence of a bifunctional catalytic system comprising a zinc-zirconium-oxide- or copper-zinc-oxide-based catalyst and a zeolite-based catalyst.1 .62) The process according to any of the preceding embodiments, wherein in step S3*), said conversion comprises a hydrodealkylation of alkylated aromatics.1 .63) The process according to any of the preceding embodiments, wherein in step S3*), said conversion comprises the separation of carbon dioxide from the product stream and its recycling to the syngas.1 .64) The process according to any of the preceding embodiments, preferably according to any of embodiments 1.52 to 1.63, wherein in step S3*), said unsaturated hydrocarbon is an aromatic hydrocarbon, preferably selected from the group consisting of benzene and toluene.In step S4), the unsaturated hydrocarbon obtained in step S3) is converted into a diamine compound according to processes known to the one of skill in the art, e.g., as described in C. Six, F. Richter, Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Isocyanates, Organic”, and the references cited therein.240953W00133In case the unsaturated hydrocarbon is an aromatic compound, such conversion is typically achieved by a sequence of nitration and subsequent hydrogenation of the nitro group(s): For instance, toluene may be dinitrated to dinitrotoluene and hydrogenated to the diamine compound toluenediamine (TDA; in particular, 2,4-TDA and 2,6-TDA). Starting from benzene, aniline is obtained by mononitration to nitrobenzene and subsequent hydrogenation of the nitro group. Condensation of aniline with formaldehyde in the presence of hydrochloric acid yields - after neutralization with sodium hydroxide - the diamine compound 4,4'-methylenedianiline (MDA).Nitration is achieved by contacting the aromatic compound with nitric acid under additional acid-catalysis (e.g., in the presence of sulfuric acid). Nitric acid is typically obtained according to the Ostwald process by catalytic oxidation of ammonia. Ammonia may be produced from nitrogen and hydrogen via the Haber-Bosch process.Preferably, said starting materials and intermediates are characterized by advantageous sustainability attributes: Nitrogen is preferably obtained by cryogenic air separation run at least in part by renewable energies.Preferred ways to produce H2 sustainably are already described above for step S1); thus, the respective embodiments mentioned for step S1) apply equally to step S4), in particular methane pyrolysis, water electrolysis, chlor-alkali electrolysis, and ammonia decomposition, as well as their embodiments and features described above. Also, sustainable hydrogen may be obtained by separation from the syngas provided in step S1) and substep S3a), respectively, and as a by-product of substep S3c). Said sustainable hydrogen may be employed both for the formation of ammonia as well as for the hydrogenation of aromatic nitro compounds to anilines.The oxygen needed for the Ostwald process is preferably as well obtained from cryogenic air separation or from water electrolysis driven at least in part by renewable energiesThe formaldehyde needed for the synthesis of MDA is preferably produced from the methanol provided in step S3). Formaldehyde is produced industrially from methanol via catalytic oxidation and / or dehydrogenation processes. Details on the formaldehyde production routes are described, e.g., in A. W. Franz et al., Ullmann's Encyclopedia of Industrial Chemistry (2016), Chapter “Formaldehyde”, in H. I. Mahdi et al., Mol. Catalysis 2023, 537, 112944, and the references cited therein. In the so-called FORMOX process, oxidation of methanol is effected with excess air in the presence of an iron molybdenum oxide catalyst at 250-400°C. Other processes use air as an oxidant, silver catalysts, and an excess of methanol at temperatures of 600-720 °C and atmospheric pressure.Also, hydrochloric acid and sodium hydroxide for the MDA synthesis are preferably obtained from other process steps: Hydrochloric acid may be recovered from step S5) and sodium hydroxide may be obtained from chlor-alkali electrolysis as described for step S 1 ) and carried out in step S2).In case the unsaturated hydrocarbon is an olefinic compound, the conversion to a diamine compound may be achieved by ammoxidation of the olefin to the corresponding vinylic nitrile compound, dimerization to the dinitrile (e.g., via electrolytic coupling), and subsequent hydrogenation to the diamine compound: For instance, hexamethylenediamine (HDA) is obtained by the catalytic reaction of propylene with ammonia and oxygen to acrylonitrile (so-called SOHIO process, as described, e.g., in J. F. Brazdil, Ullmann's Encyclopedia of Industrial Chemistry (2012), Chapter “Acrylonitrile” and the references cited therein), hydrodimerization to adiponitrile (see, e.g., M. M. Baizer, D. E. Danly, Chem. Technol. 1980, 10, 161 - 164, 302 - 311 ; US 3193480; US 3529011; and EP 0314383), and hydrogenation of the dinitrile to the diamine compound HDA.240953W00134Preferably, the employed ammonia, hydrogen, and oxygen originate from sustainable sources, as mentioned above, and renewable electrical energy is used where needed.Preferred Embodiments1 .65) The process according to any of the preceding embodiments, wherein step S4) comprises the nitration, in particular the mononitration or dinitration, of an aromatic compound and the hydrogenation of the nitro group(s).1 .66) The process according to embodiment 1.65, wherein step S4) further comprises the condensation of an anilinic compound, preferably of aniline, with formaldehyde, more preferably the condensation of two equivalents of aniline with one equivalent of formaldehyde, in the presence of hydrochloric acid and optionally the neutralization using sodium hydroxide.1 .67) The process according to embodiment 1 .66, wherein in step S4), at least a portion of said formaldehyde is provided from the oxidation of methanol of step S3).1 .68) The process according to any of embodiments 1 .66 to 1 .67, wherein in step S4), at least a portion of said hydrochloric acid is provided from hydrogen chloride recovered from step S5).1 .69) The process according to any of embodiments 1 .66 to 1.68, wherein in step S4), at least a portion of said sodium hydroxide is provided from chlor-alkali electrolysis, preferably carried out in step S2).1 .70) The process according to any of embodiments 1 .65 to 1 .69, wherein in step S4), said nitration is carried out with nitric acid obtained by oxidation of ammonia with oxygen, wherein said ammonia is preferably obtained by reaction of nitrogen with hydrogen.1.71) The process according to any of embodiments 1.1 to 1.64, wherein step S4) comprises the ammoxidation of an olefinic compound to obtain an a,|3-unsaturated nitrile, the dimerization of the nitrile, in particular its hydrodimerization, to obtain a dinitrile, and hydrogenation of the dinitrile.1 .72) The process according to embodiment 1.71, wherein in step S4) , said ammoxidation is carried out using oxygen and ammonia, wherein said ammonia is preferably obtained by reaction of nitrogen with hydrogen.1 .73) The process according to any of embodiments 1 .65 to 1 .72, wherein in step S4), at least a portion of the needed hydrogen is provided by separation from syngas of step S1 ) and S3a), respectively, or is recovered from substep S3c) or is provided from sustainable sources, preferably from water electrolysis, in particular as carried out in step S1 ), chlor-alkali electrolysis, in particular as carried out in step S2), methane pyrolysis, or decomposition of ammonia.1 .74) The process according to any of embodiments 1 .70 to 1 .73, wherein in step S4), at least a portion of the needed nitrogen is obtained by cryogenic air separation, preferably driven by renewable energies.1 .75) The process according to any of embodiments 1 .70 to 1 .74, wherein in step S4), at least a portion of the needed oxygen is obtained by cryogenic air separation, preferably driven by renewable energies, or from water electrolysis, in particular as carried out in step S 1 ).1 .76) The process according to any of the preceding embodiments, wherein in step S4), the obtained diamine compound is selected from the group consisting of MDA, TDA, and HDA, preferably from the group consisting of MDA and TDA.240953W00135Step S5)In step S5), the diamine compound obtained in step S4) is transformed into a diisocyanate compound by reaction with phosgene as provided in step S2) according to processes known to the one of skill in the art, e.g., as described in C. Six, F. Richter, Ullmann's Encyclopedia of Industrial Chemistry, 2012, Chapter “Isocyanates, Organic”, and the references cited therein.For instance, TDA is thus converted to toluene diisocyanate (TDI), MDA to methylene diphenyl diisocyanate (MDI), and HDA to hexamethylene diisocyanate (HDI).As a side product of the phosgenation of amines, hydrogen chloride is formed which is preferably recovered and used as a feedstock for the production of chlorine, e.g., as described for step S2), or in the synthesis of MDA, as described in step S4).Preferred Embodiments1 .77) The process according to any of the preceding embodiments, wherein step S5) comprises the recovery of hydrogen chloride.1 .78) The process according to any of the preceding embodiments, wherein in step S4), the obtained diisocyanate is selected from the group consisting of TDI, MDI, and HDI, preferably from the group consisting of TDI and MDI.Further process stepsThe process according to the invention may comprise further optional steps where needed or advisable to improve the overall performance of the process. In particular, purification steps may be applied to the streams obtained in the process steps described hereinbefore to improve their properties or to meet certain specifications for further process steps. Also, separation steps may be carried out on intermediate or product streams to improve the purity of the reaction products.Also, step S6), described hereinafter, may be comprised by the process of the invention.Step S6)Within the scope of this invention, the diisocyanates obtained in step S5) may be converted further to downstream products, especially to diisocyanate-derived polymers. In particular, the diisocyanates may be used along with polyols to synthesize polyurethanes and along with polyamines to synthesize polyureas. Also, polyamides may be obtained with dicarboxylic acids and polyimides with carboxylic acid dianhydrides.The publication Prior Art Disclosure; Issue 684; paragraphs

[1000] to

[8005] ; ISSN: 2198-4786; published: February 12, 2024, will be regarded as Reference RF1 , which is incorporated herein by reference in its entirety. Preferably, the downstream product PRF1 is a product as described in Reference RF1; paragraphs

[1000] to

[8005] , Preferably, the process described herein is further a process for the production of a downstream product, preferably product PRF1. The converting step to obtain the product PRF1 preferably comprises one or more step(s) as described below and can be performed by conventional methods well known to a person skilled in the art. The converting step preferably comprises one or more step(s) selected from: recycling, preferably depolymerizing, gasifying, pyrolyzing, and / or steam cracking; and / or240953W00136 purifying, preferably crystallizing, (solvent) extracting, distilling, evaporating, hydrotreating, absorbing, adsorbing and / or subjecting to ion exchanger; and / or assembling, preferably foaming, synthesizing, chemical conversion, chemically transforming, polymerizing and / or compounding; and / or forming, preferably foaming, extruding and / or molding; and / or finishing, preferably coating and / or smoothing.In addition, the one or more step(s) are described in detail in Reference RF1 ; paragraphs

[1000] to

[8005] ,The term “building block”, as used herein, comprises compounds, which are in a gaseous or liquid state under standard conditions of 0 °C and 0.1 MPa. Building blocks are typically used in chemical industry to form secondary products, which provide a higher structural complexity and / or higher molecular weight than the building block on which the secondary product is based. The building block is preferably selected from the group consisting of hydrogen, carbon monoxide, carbon dioxide, ethylene oxide, ethylene glycols, syngas comprising a mixture of hydrogen and carbon monoxide, alkanes, alkenes, alkynes and aromatic compounds. The alkanes, alkenes, alkynes and aromatic compounds comprise in particular 1 to 12 carbon atoms, respectively.The term “monomer”, as used herein, comprises molecules, which can react with each other to form polymer chains by polymerization. The monomer is preferably selected from the group consisting of (meth)acrylic acid, salts of (meth)acry I ic acid; in particular sodium, potassium and zinc salts; (meth)acrolein and (meth)acrylates. (Meth)acrylates comprising 1 to 22 carbon atoms are preferred, in particular comprising 1 to 8 carbon atoms. The terms (meth)acrylic acid, (meth)acrolein or (meth)acrylate relate to acrylic acid, acrolein or acrylate and also to methacrylic acid, methacrolein or methacrylate, where applicable. Further, the monomer can be selected from hexamethylenediamine (HMD) and adipic acid.The building block can further be an intermediate compound. The term “intermediate compound”, as used herein, comprises organic reagents, which are applied for formation of compounds with higher molecular complexity. The intermediate compound can be selected for example from the group consisting of phosgene, polyisocyanates and propylene oxide. The polyisocyanates are in particular aromatic di- and polyisocyanates, preferably toluene diisocyanate (TDI) and / or diphenylmethane diisocyanate (methylene diphenyl diisocyanate; MDI).The building block and the monomer and typical converting step(s) to obtain the building block or monomer are described in more detail in paragraphs

[1000] to

[1012] of Reference RF1.The term “polymer A”, as used herein, comprises thermoplastic, e.g., polyamide or thermoplastic polyurethane, thermoset, e.g., polyurethane, elastomer, e.g., polybutadiene, or a copolymer or a mixture thereof and is defined in more detail in paragraphs

[2001] to

[2007] of Reference RF1.The term “polymer composition A”, as used herein, comprises all compositions comprising a polymer as described above and one or more additive(s), e.g. reinforcement, colorant, modifier and / orflame retardant, and is defined in more detail in paragraph

[2008] of Reference RF1.The term “polymer product A”, as used herein, comprises any product comprising the polymer A and / or polymer composition A as described above and is defined in more detail in paragraphs

[2009] and

[2010] of Reference RF1 .The step(s) to obtain the polymer, preferably polymer A, polymer composition, preferably polymer composition A or polymer product, preferably polymer product A is / are described in more detail in paragraph

[2011] of Reference RF1.240953W00137The term “industrial use polymer'1, as used herein, comprises rheology, polycarboxylate, alkoxylated polyalkylenamine, alkoxylated polyalkylenimine, polyether-based, dye inhibition and soil release cleaning polymers defined in more detail in paragraphs

[3035] to

[3044] of Reference RF1. The term “industrial use surfactant”, as used herein, comprises nonionic, anionic and amphoteric industrial use surfactants defined in more detail in paragraphs

[3008] to

[3034] of Reference RF1. The term “industrial use descaling compound”, as used herein, comprises non-phosphate based builders (NPB) and phosphonates (CoP) described in more detail in paragraphs

[3001] to

[3005] of Reference RF1. The term “industrial use biocide”, as used herein, refers to a chemical compound that kills microorganisms or inhibits their growth or reproduction defined in more detail in paragraphs

[3006] to

[3007] of Reference RF1. The term “industrial use solvent”, as used herein, comprises alkyl amides, alkyl lactamides, alkyl esters, lactate esters, alkyl diester, cyclic alkyl diester, cyclic carbonates, aromatic aldehydes and aromatic esters defined in more detail in paragraphs

[3045] to

[3055] of Reference RF1 . The term “industrial use dispersant”, as used herein, comprises anionic and non-ionic industrial use dispersants defined in more detail in paragraphs

[3056] to

[3058] of Reference RF1. The term “composition and / or formulation thereof” with reference to the industrial use polymers, industrial use surfactants, descaling compounds and / or industrial use biocides refers to industrial use compositions and / or institutional use products and / or fabric and home care products and / or personal care products defined in more detail in paragraph

[3059] of Reference RF1 . The converting step(s) to obtain the industrial use polymer, industrial use surfactant, descaling compound and / or industrial use biocide are defined in more detail in paragraph

[3060] of Reference RF1. The converting steps to obtain the industrial use composition or formulation of the industrial use polymer, industrial use surfactant, descaling compound and / or industrial use biocide are defined in more detail in paragraph

[3061] of Reference RF1.The term “agrochemical composition”, as used herein, typically relates to a composition comprising an agrochemically active ingredient and at least one agrochemical formulation auxiliary. Examples of agrochemical compositions, active ingredients and auxiliaries are described in more detail in Reference RF1, paragraph

[4001] ,The agrochemical composition may take the form of any customary formulation. The agrochemical compositions are prepared in a known manner, e.g. described by Mollet and Grubemann, Formulation technology, Wiley VCH, Weinheim, 2001 ; or Knowles, New developments in crop protection product formulation, Agrow Reports DS243, T&F Informa, London, 2005. The converting step(s) to obtain the agrochemically active ingredients and auxiliaries may be conducted in analogy to the production step(s) of their analogues that are based on petrochemicals or other precursors that are not gained by recycling processes. In addition, conversion to compounds mentioned in sections “Polymer” and “Cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter, further cosmetic ingredient or compositions or formulations thereof” may be performed as described in these sections as well as the respective paragraphs in Reference RF1.The term active pharmaceutical ingredients and / or intermediates thereof, as used herein, comprises substances that provide pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body. Intermediates thereof are isolated products that are generated during a multi-step route of synthesis of an active pharmaceutical ingredient. The term pharmaceutical excipients, as used herein, comprises compounds or compound mixtures used in compositions for various pharmaceutical applications, which are not substantially pharmaceutically active on itself. Active pharmaceutical ingredients and / or intermediates thereof and pharmaceutical excipients are defined in more detail in paragraph

[5001] of Reference RF1 .240953W00138The converting step(s) to obtain the active pharmaceutical ingredients and / or intermediates thereof and pharmaceutical excipients may comprise one or more synthesis steps and can be performed by conventional synthesis and techniques well known to a person skilled in the art.The terms animal feed additives, human food additives, dietary supplements, as used herein, comprises Vitamins, Pro- Vitamins and active metabolites thereof including intermediates and precursors, especially Vitamin A, B, E, D, K and esters thereof, like acetate, propionate, palmitate esters or alcohols thereof like retinol or salts thereof and any combinations thereof; Tetraterpenes, especially isoprenoids like carotenoids and xanthophylls including their intermediates and precursors as well as mixtures and derivates thereof, especially beta carotene, Canthaxanthin, Citranaxanthin, Astaxanthin, Zeaxanthin, Lutein, Lycopene, Apo-carotenoids, and any combinations thereof; organic acids, especially formic acid, propionic acid and salts thereof, such as sodium, calcium or ammonium salts, and any combinations thereof, such as but not limited to mixtures of formic acid and sodium formiate, propionic acid and ammonium propionate, formic acid and propionic acid, formic acid and sodium formiate and propionic acid, propionic acid and sodium propionate and formic acid and sodium formiate; glycerides of carboxylic acids and short and medium chain fatty acids, conjugated linoleic acids, such as omega-6 fatty acid (C18:2) methyl ester and 1 ,2-propandiol and beverage stabilizers, such as polyvinyl pyrrolidone-polymer or polyvi nylimid azole / polyvinylpyrrolidone-copolymer. Animal feed additives, human food additives and dietary supplements are defined in more detail in paragraph

[5002] of Reference RF1 .The converting step(s) to obtain the animal feed additives, human food additives, dietary supplements may comprise one or more synthesis steps and can be performed by conventional synthesis and techniques well known to a person skilled in the art.The terms aroma chemical and aroma composition as used herein, comprise a volatile organic substance with a molecular weight between 70-250 g / mol comprising a functional group with a carbon skeleton of C5-C16 carbon atoms comprising linear, branched, cyclic, for example with a ring size of C5-C18, bicyclic or tricyclic aliphatic chains and but not necessarily one or more unsaturated structural elements like double bonds, triple bonds, aromatics or heteroaromatics and preferably the one or more additional functional groups are selected from alcohol, ether, ester, ketone, aldehyde, acetal, carboxylic acid, nitrile, thiol, amine. In one aspect, the aroma chemical is a terpene-based aroma chemical, for example selected from monoterpenes and monoterpenoids, sesquiterpenes and sesquiterpenoids, diterpenes, triterpenes or tetraterpenes. Aroma chemicals can be combined with further aroma chemicals to give an aroma composition. Aroma chemicals and aroma compositions are defined in more detail in paragraph

[5003] of Reference RF1.The converting step(s) to obtain the aroma chemical and aroma composition may comprise one or more synthesis steps and can be performed by conventional synthesis and techniques well known to a person skilled in the art.The term “aqueous polymer dispersion”, as used herein, comprises aqueous composition(s) comprising dispersed polymer(s) and is defined in more detail in the section

[6001] entitled “aqueous polymer dispersion” of Reference RF1 . The dispersed polymer(s) may be selected from acrylic emulsion polymer(s), styrene acrylic emulsion polymer(s), styrene butadiene dispersion(s), aqueous dispersion(s) comprising composite particles, acrylate alkyd hybrid dispersions), polyurethane(s) (including UV-curable polyurethanes) and polyurethane - poly(meth)acrylate hybrid poly- mer(s). The term “emulsion polymer”, as used herein, comprises polymer(s) made by free-radical emulsion polymerization. Aqueous polyurethane dispersion(s) are defined in more detail in the section

[6002] entitled “Polyurethane240953W00139 dispersions” of Reference RF1. UV-curable polyurethane(s) is / are defined in more detail in the section

[6017] of Reference RF1. Polyurethane - poly(meth)acrylate hybrid polymer(s) is / are defined in more detail in the section

[6016] of Reference RF1.The term “polymeric dispersant”, as used herein, comprises preferably polymer(s) comprising polyether side chain, in particular polycarboxylate ether polymer(s) and polycondensation product(s) defined in more detail in paragraph

[6020] entitled “Polymeric dispersant” of Reference RF1.The converting (polymerization) step(s) to obtain the aqueous polymer dispersion(s) comprising emulsion polymer(s) is / are defined in more detail in the section

[6003] entitled “Emulsion polymerization” of Reference RF1.The converting (polymerization) step(s) to obtain the aqueous polyurethane dispersion(s) is / are defined in more detail in the section

[6014] entitled “Process for the preparation of aqueous polyurethane dispersions” and section

[6017] entitled “Aqueous UV-curable polyurethane dispersions, their preparation and use and compositions containing them” of Reference RF1.Composition(s) and uses of aqueous polymer dispersion(s) and of polymeric dispersant(s) are defined in more detail in the following sections of Reference RF1 : section

[6004] entitled “Uses of aqueous polymer dispersions”, section

[6005] entitled “Binders for architectural and construction coatings” section

[6006] entitled “Binders for paper coating” section

[6007] entitled “Binders for fiber bonding” section

[6008] entitled “Adhesive polymers and adhesive compositions” section

[6015] entitled “Aqueous polyurethane dispersions suitable for use in coating compositions” section

[6016] entitled “Aqueous polyurethane - poly(meth)acrylate hybride polymer dispersions suitable for use in coating compositions” section

[6017] entitled “Aqueous UV-curable polyurethane dispersions, their preparation and use and compositions containing them” section

[6018] entitled “Inorganic binder compositions comprising polymeric dispersants and their use”

[6019] 100% curable coating compositionsUV-crosslinkable poly(meth)acrylate(s) and its / their uses are defined in more detail in section

[6009] entitled “UV- crosslinkable poly(meth)acrylates for use in UV-curable solvent-free hotmelt adhesives and their use for making pressure-sensitive self-adhesive articles” of Reference RF1.Polyisocyanate(s), composition(s) comprising them and their uses are defined in more detail in section

[6010] entitled “Polyisocyanates” of Reference RF1.Hyperbranched polyester polyol(s) and its / their uses are defined in more detail in section

[6011] entitled “Organic solvent based hyperbranched polyester polyols suitable for use in coating compositions” of Reference RF1. The converting step(s) to obtain the hyperbranched polyester polyols is / are defined in more detail in the section

[6012] entitled “Preparation of organic solvent based hyperbranched polyester polyols” of Reference RF1. Coating composition(s) comprising hyperbranched polyester polyol(s), polyisocyanate(s) and additive(s) and substrate(s) coated therewith are defined in more detail in section

[6013] entitled “Organic solvent based two component coating compositions comprising hyperbranched polyester polyols and polyisocyanates” of Reference RF1.240953W00140Unsaturated polyester polyol(s), solvent-based coating composition(s) comprising said unsaturated polyester polyol(s) and substrate(s) for coating with said coating composition(s) are defined in more detail in section

[6018] entitled “Organic solvent based coating composition comprising unsaturated polyester polyols” of Reference RF1. 100% curable coating composition(s) is / are defined in more detail in section

[6019] of Reference RF1.Polymeric dispersant(s) for inorganic binder compositions is / are defined in more detail in section

[6020] of Reference RF1 . The inorganic binder composition(s) comprising the polymeric dispersants and their use are defined in more detail in section

[6021] of Reference RF1. The converting step(s) to obtain the polymeric dispersant(s) are defined in more detail in section

[6020] of Reference RF1. The term “inorganic binder composition” comprising the polymeric dispersants), as used herein, comprises preferably in particular hydraulically setting compositions and compositions comprising calcium sulfate and is defined in more detail in section

[6021] of Reference RF1 entitled “Inorganic binder compositions comprising the polymeric dispersant and their use”. Specific building material formulation(s) comprising polymeric dispersant(s) or building product(s) produced by a building material formulation comprising a polymeric dispersant are disclosed in more detail in section

[6021] of Reference RF1.The term “cosmetic surfactant”, as used herein, comprises non-ionic, anionic, cationic and amphoteric surfactants and is defined in more detail in paragraph

[7002] of Reference RF1. The term “emollient”, as used herein, refers to a chemical compound used for protecting, moisturizing, and / or lubricating the skin and is defined in more detail in paragraph

[7003] of Reference RF1 . The term “wax”, as used herein, comprises pearlizers and opacifiers and is defined in more detail in paragraph

[7004] of Reference RF1 . The term “cosmetic polymer”, as used herein, comprises any polymer that can be used as an ingredient in a cosmetic formulation and is defined in more detail in paragraph

[7005] of Reference RF1 . The term “UV filter”, as used herein, refers to a chemical compound that blocks or absorbs ultraviolet light and is defined in more detail in paragraph

[7006] of Reference RF1. The term “further cosmetic ingredient”, as used herein, comprises any ingredient suitable for making a cosmetic formulation. Several sources disclose cosmetically acceptable ingredients. E. g. the database Cosing on the internet pages of the European Commission discloses cosmetic ingredients and the International Cosmetic Ingredient Dictionary and Handbook, edited by the Personal Care Products Council (PCPC), discloses cosmetic ingredients. The term “composition and / or formulation thereof” with reference to the cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter and / or further cosmetic ingredient refers to personal care and / or cosmetic compositions or formulations defined in more detail in paragraph

[7007] of Reference RF1. The converting step(s) to obtain the cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter or further cosmetic ingredient is / are defined in more detail in paragraph

[7008] of Reference RF1.The terms “polymer B”, “polymer composition B”, “coating composition”, “other functional composition”, “foil”, “molded body”, “coating” and “coated substrate” are well known to the person skilled in the art and are defined in more detail from paragraph

[8000] to

[8005] of Reference RF1.Preferred embodiments1.79) A process to produce at least one downstream product, preferably at least one product PRF1, the process comprising the process according to any of the preceding embodiments and further comprising step S6) S6) converting at least a portion of the diisocyanate obtained in step S5) to obtain at least one downstream product.240953W001411.80) The process according to embodiment 1.79, wherein the product PRF1 is selected from: i) building block or monomer; or ii) polymer, preferably polymer A, polymer composition, preferably polymer composition A, or polymer product, preferably polymer product A; orHi) cleaning polymer, cleaning surfactant, descaling compound, cleaning biocide or composition or formulation thereof; or iv) agrochemical composition, agrochemical formulation auxiliary or agrochemically active ingredient; or v) active pharmaceutical ingredient or intermediate thereof, pharmaceutical excipient, animal feed additive, human food additive, dietary supplements, aroma chemical or aroma composition; or vi) aqueous polymer dispersion, preferably polyurethane or polyurethane - poly(meth)acrylate hybrid polymer dispersion, emulsion, binder for paper and fiber coatings, UV-curable acrylic polymer for hot melts and coatings polyisocyanates, hyperbranched polyester polyol, polymeric dispersant for inorganic binder compositions, unsaturated polyester polyol or 100% curable composition; or vii) cosmetic surfactant, emollient, wax, cosmetic polymer, UV filter, further cosmetic ingredient or composition or formulation thereof; or viii) polymer B, polymer composition B, coating composition, other functional composition, foil, molded body, coating or coated substrate.1.81) The process according to any one of embodiments 1.79 to 1 .80, wherein the content of said diisocyanate in the product PRF1 is 1 weight-% or more, preferably 2 weight-% or more, more preferably 5 weight-% or more, more preferably 15 weight-% or more, more preferably 30 weight-% or more, more preferably 40 weight-% or more, more preferably 60 weight-% or more, more preferably 80 weight-% or more, more preferably 90 weight-% or more, more preferably 95 weight-% or more; and / or wherein the content of said diisocyanate in the product PRF1 is 100 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 50 weight-% or less, more preferably 25 weight-% or less, more preferably 10 weight-% or less; and preferably wherein the content is determined based on identity preservation and / or segregation and / or mass balance and / or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.Further embodiments of the first and second aspect of the invention are described by the combination of any and each of the above definitions and embodiments with one another, in particular by way of FIGs 1-5:- FIG 1 depicts the production of diisocyanate from syngas, preferably from sustainable syngas:CO is separated from syngas and transformed to phosgene according to step S2). Syngas is also converted to methanol according to substep S3b), further to an unsaturated hydrocarbon according to substep S3c) and to a diamine according to step S4). Diamine and phosgene react to form the diisocyanate according to step S5).Of note, methanol or phosgene may be provided from sources other than said syngas.- FIG 2 depicts the production of diisocyanate from syngas, preferably from sustainable syngas, and phosgene:240953W00142Syngas is converted to unsaturated hydrocarbons according to step S3*), further to a diamine according to step S4). Diamine and phosgene react to form the diisocyanate according to step S5).Of note, phosgene may be obtained as described for FIG 1 .- FIG 3 depicts the diamine formation using hydrogen from syngas. FIG 3 is meant to include all the features and embodiments of FIG 1 or FIG 2, although not reproduced explicitly:Hydrogen is separated from syngas as described in step S1) and reacted with N2 to ammonia according to the Haber- Bosch process. As described in step S4), ammonia is either oxidized to nitric acid and used for nitration of aromatic compounds or it is used along with oxygen for the ammoxidation of olefins to form a nitrile. A part of the hydrogen is also employed to form the diamine by reducing the nitro and nitrile groups, respectively.- FIG 4 depicts the phosgene formation using carbon monoxide from syngas. FIG 4 is meant to include all the features and embodiments of FIG 1 or FIG 2 and of FIG 3, although not reproduced explicitly:Carbon monoxide is separated from syngas as described in step S2) and reacted with chlorine to phosgene. Said chlorine is obtained from chlor-alkali electrolysis of sodium chloride solution as described in step S2). Though not depicted explicitly, hydrogen which is a by-product of the chlor-alkali electrolysis may be used as described for FIG 3 for the syngas-derived hydrogen.- FIG 5 depicts a circular process including the production of diisocyanate from syngas which is obtained from diiso- cyanate-derived plastic waste. FIG 5 is meant to include all the features and embodiments of FIG 1 or FIG 2 and of FIG 3 and FIG 4, although not reproduced explicitly:Diisocyanate is used to produce polymers like polyurethanes or polyureas and polymer products derived therefrom, e.g., according to step S6). After the end of their lifetime, these polymer products become plastic waste that may be used as a feedstock for syngas by gasification or pyrolysis processes described for step S1).The different embodiments described herein for the first aspect of the invention apply analogously to the further aspects of the invention.In a third aspect, the present disclosure provides a system for producing a diisocyanate, the system comprising the unitsU1) syngas providing unit;U2) phosgene providing unit;U3) unsaturated, preferably aromatic, hydrocarbon production unit;U4) diamine production unit; andU5) diisocyanate production unit.As used herein, the term system refers to an arrangement of units that allows for the exchange of material and / or energy streams between the different units. Said exchange may be accomplished by fluid connections, by pipelines, or by other means of transportation. In particular, said system may be embodied by a production plant, more specifically by an integrated production plant.240953W00143Preferred Embodiments3.1) The system according to the third aspect of the invention.3.2) The system according to any of the preceding embodiments, wherein the system is a production plant, preferably an integrated production plant.Unit U1)The syngas providing unit U1) is equipped to perform process step S1) as well as syngas separation as described above for step S2), including its different embodiments.In particular, it is equipped to receive and store syngas and / or a feedstock to produce syngas and to provide syngas or components thereof to downstream units, e.g., syngas to unit U3), CO to unit U2), and H2 to unit U4). In addition, it may receive and store H2 (optionally also 02) from a H2 production unit, e.g., a water electrolysis unit. Similarly, it may receive and store 002 from a 002 production subunit, e.g., a carbon capture subunit, e.g., from unit U3).Unit U 1) may comprise a raw material pretreatment subunit that is fed with raw material and is equipped to process said raw material as described for step S1 ). Further, it may comprise a syngas production subunit, e.g., a reforming subunit, a gasification subunit, a pyrolysis subunit, a rWGS subunit, and / or a SOEC subunit. Preferably, said syngas production subunit is connected to a 002 production unit to capture 002 that is co-produced in the syngas production process. Also, unit U 1 ) may comprise a syngas purification subunit as well as a subunit for adjusting the stoichiometric number, e.g., a WGS subunit. In addition, unit U1) may comprise a syngas separation subunit for separating certain components from the syngas, in particular to obtain CO or hydrogen.Preferred Embodiments3.3) The system according to any of the preceding embodiments, wherein unit U1) is fluidly connected and arranged upstream to unit U2).3.4) The system according to any of the preceding embodiments, wherein unit U1) is fluidly connected and arranged upstream to unit U3).3.5) The system according to any of the preceding embodiments, wherein unit U1) is fluidly connected and arranged upstream to unit U4).3.6) The system according to any of the preceding embodiments, wherein unit U1) is fluidly connected and arranged downstream to a C02 production unit.3.7) The system according to any of the preceding embodiments, wherein unit U1) is fluidly connected and arranged downstream to a H2 production unit.3.8) The system according to any of the preceding embodiments, wherein unit U1) is fluidly connected and arranged downstream to unit U3).3.9) The system according to any of the preceding embodiments, wherein unit U1) comprises a raw material pretreatment subunit.3.10) The system according to any of the preceding embodiments, wherein unit U 1) comprises at least one syngas production subunit selected from the group consisting of a steam reforming subunit, a partial oxidation subunit,240953W00144 an autothermal reforming subunit, a dry reforming subunit, a gasification subunit, a pyrolysis subunit, a rWGS subunit, and a SOEC subunit.3.11) The system according to any of the preceding embodiments, wherein unit U1) comprises a syngas purification subunit.3.12) The system according to any of the preceding embodiments, wherein unit U1) comprises a subunit for adjusting the stoichiometric number.3.13) The system according to any of the preceding embodiments, wherein unit U 1 ) comprises a syngas separation subunit.Unit U2)The phosgene providing unit U2) is equipped to perform process step S2) as described above, including its different embodiments.In particular, it is equipped to receive and store carbon monoxide and / or chlorine and to provide phosgene to unit U5). In addition, it may receive and store hydrogen chloride from unit U5) and to produce chlorine therefrom.Unit U5) may comprise a phosgene production subunit that is equipped to produce phosgene according to step S2). Further, it may comprise a chlorine production subunit, e.g., a chlor-alkali electrolysis subunit, a hydrochloric acid electrolysis subunit or a hydrogen chloride oxidation subunit. Preferably, hydrogen chloride needed for the chlorine production is at least in part provided by unit U5).Preferred Embodiments3.14) The system according to any of the preceding embodiments, wherein unit U2) is fluidly connected and arranged upstream to unit U5).3.15) The system according to any of the preceding embodiments, wherein unit U2) is fluidly connected and arranged downstream to unit U1).3.16) The system according to any of the preceding embodiments, wherein unit U2) is fluidly connected and arranged downstream to unit U5).3.17) The system according to any of the preceding embodiments, wherein unit U2) is fluidly connected and arranged downstream to a chlorine production unit.3.18) The system according to any of the preceding embodiments, wherein unit U2) comprises a phosgene production subunit.3.19) The system according to any of the preceding embodiments, wherein unit U2) comprises a chlorine production subunit selected from the group consisting of a chlor-alkali electrolysis subunit, a hydrochloric acid electrolysis subunit and a hydrogen chloride oxidation subunit.Unit U3)Unit U3) for producing unsaturated hydrocarbons is equipped to perform step S3) and S3*), respectively, as described above, including their different embodiments.240953W00145In particular, it is equipped to receive a syngas stream, preferably from unit U 1), or to provide syngas according to substep S3a), optionally to store syngas, optionally to convert it to methanol (and / or dimethyl ether), and to produce unsaturated hydrocarbons from said syngas and / or from said methanol (and / or dimethyl ether). Also, unit U3) is equipped to perform post-treatment of said unsaturated hydrocarbons and / or the separation of aromatics. Preferably, unit U3) is equipped to carry out one or more of upgrading of by-products, intermediate product separation, methanol recycling, hydrogen recovery, catalyst regeneration, and hydrodealkylation of alkylated aromatics. Furthermore, unit U3) is equipped to provide unsaturated hydrocarbons to unit U4). Optionally, it is equipped to capture carbon dioxide that is formed in the course of its operation and to provide it to unit U 1 ). Similarly, it may recover co-produced hydrogen and provide it to unit U4).Unit U3) may comprise a methanol production subunit to carry out substep S3b). Further, it comprises a hydrocarbon production subunit, e.g., an MTA subunit, an MTO subunit, an MTP subunit, and / or a syngas-to-aromatics subunit, to carry out substep S3c) or step S3*). Unit U3) may also comprise a post-treatment subunit, an aromatics separation subunit, a by-product upgrading subunit, an intermediate product separation subunit, a methanol recycling subunit, a hydrogen recovery subunit, a catalyst regeneration subunit, and / or an aromatics hydrodealkylation subunit.Preferred Embodiments3.20) The system according to any of the preceding embodiments, wherein unit U3) is fluidly connected and arranged upstream to unit U4).3.21 ) The system according to any of the preceding embodiments, wherein unit U3) is fluidly connected and arranged upstream to unit U1).3.22) The system according to any of the preceding embodiments, wherein unit U3) is fluidly connected and arranged downstream to unit U1).3.23) The system according to any of the preceding embodiments, wherein unit U3) comprises a syngas providing subunit.3.24) The system according to any of the preceding embodiments, wherein unit U3) comprises a methanol production subunit.3.25) The system according to any of the preceding embodiments, wherein unit U3) comprises a hydrocarbon production subunit selected from the group consisting of an MTA subunit, an MTO subunit, an MTP subunit, and a syngas-to-aromatics subunit.3.26) The system according to any of the preceding embodiments, wherein unit U3) comprises a post-treatment subunit and / or an aromatics separation subunit.3.27) The system according to any of the preceding embodiments, wherein unit U3) comprises a by-product upgrading subunit, an intermediate product separation subunit, a methanol recycling subunit, a hydrogen recovery subunit, a catalyst regeneration subunit, and / or an aromatics hydrodealkylation subunit.Unit U4)The diamine production unit U4) is equipped to perform step S4) as described above, including its different embodiments.240953W00146In particular, it is equipped to receive unsaturated hydrocarbons from unit U3) and to provide diamines to unit U5). Also, unit U4) may receive, as needed for the particular diamine to be produced, nitric acid, formaldehyde (e.g., obtained by oxidation of methanol provided by unit U3)), ammonia, hydrogen (e.g., obtained from unit U1) and / or from unit U3)), oxygen, hydrochloric acid (e.g., obtained from unit U5)), and / or sodium hydroxide.Unit U4) may comprise an aromatics nitration subunit, an olefin ammoxidation subunit, and / or a hydrogenation subunit to hydrogenate nitro or nitrile compounds.Specifically, unit U4) may be an MDA production unit, a TDA production unit, or an HDA production unit, preferably an MDA or TDA production unit.Preferred Embodiments3.28) The system according to any of the preceding embodiments, wherein unit U4) is fluidly connected and arranged upstream to unit U5).3.29) The system according to any of the preceding embodiments, wherein unit U4) is fluidly connected and arranged downstream to unit U3).3.30) The system according to any of the preceding embodiments, wherein unit U4) is fluidly connected and arranged downstream to unit U1).3.31 ) The system according to any of the preceding embodiments, wherein unit U4) is fluidly connected and arranged downstream to unit U5).3.32) The system according to any of the preceding embodiments, wherein unit U4) comprises an aromatics nitration subunit.3.33) The system according to any of the preceding embodiments, wherein unit U4) comprises an olefin ammoxidation subunit.3.34) The system according to any of the preceding embodiments, wherein unit U4) comprises a hydrogenation subunit.3.35) The system according to any of the preceding embodiments, wherein unit U4) comprises a formaldehyde production subunit.3.36) The system according to any of the preceding embodiments, wherein unit U4) is selected from the group consisting of an MDA production unit, a TDA production unit, and an HDA production unit, preferably selected from the group consisting of an MDA production unit and a TDA production unit.Unit U5)The diisocyanate production unit U5) is equipped to perform step S5) as described above, including its different embodiments.In particular, it is equipped to receive phosgene from unit U2) and diamines from unit U4). Further, it may provide diisocyanates to unit U6). Also, unit U5) may be equipped to recover hydrogen chloride and hydrochloric acid, respectively, and to provide it to unit U2) (for the production of chlorine) and / or to unit U4).Unit U5) may comprise a hydrogen chloride recovery subunit.240953W00147Specifically, unit U5) may be an MDI production unit, a TDI production unit, or an HDI production unit, preferably an M DI production unit or a TDI production unit.Preferred Embodiments3.37) The system according to any of the preceding embodiments, wherein unit U5) is fluidly connected and arranged upstream to unit U6).3.38) The system according to any of the preceding embodiments, wherein unit U5) is fluidly connected and arranged downstream to unit U2).3.39) The system according to any of the preceding embodiments, wherein unit U5) is fluidly connected and arranged downstream to unit U4).3.40) The system according to any of the preceding embodiments, wherein unit U5) is fluidly connected and arranged upstream to unit U2).3.41 ) The system according to any of the preceding embodiments, wherein unit U5) is fluidly connected and arranged upstream to unit U4).3.42) The system according to any of the preceding embodiments, wherein unit U5) comprises a hydrogen chloride recovery subunit.3.43) The system according to any of the preceding embodiments, wherein unit U5) is selected from the group consisting of an MDI production unit, a TDI production unit, and an HDI production unit, preferably selected from the group consisting of an MDI production unit and a TDI production unit.Further unitsThe system according to the invention may comprise further units and subunits, e.g., for performing purification and separation steps where needed or advisable. Also, the system may comprise one or more downstream conversion units U6), as described below.Unit U6)The downstream conversion unit U6) is equipped to perform process step S6) as described above, including its different embodiments. In particular, it is equipped to receive and store diisocyanate as well as potential reaction partners like polyols, polyamines, dicarboxylic acids, and carboxylic acid dianhydrides and to produce downstream products thereof.Preferred Embodiments3.44) The system according to any of the preceding embodiments, the system further comprising at least one unit U6)U6) downstream conversion unit.3.45) The system according to any of the preceding embodiments, wherein unit U6) is fluidly connected and arranged downstream to unit U5).240953W001483.46) The system according to any of the preceding embodiments, wherein unit U6) is selected from the group consisting of a polyurethane production unit, a polyurea production unit, a polyamide production unit, and a polyimide production unit.Further embodiments of the third aspect of the invention are described by the combination of any and each of the above definitions and embodiments with one another, in particular by way of FIGs 6 and 7.FIG 6 depicts a system for performing the processes according to FIGs 1 to 2. Of note, unit U6) and the production of polymers from diisocyanates is an optional element of the system.FIG 7 depicts a system for performing the process according to FIG 3. U1) delivers hydrogen to unit U4) where it is employed for hydrogenation steps. Of note, unit U6) and the production of polymers from diisocyanates is an optional element of the system.In further aspects, the invention relates to the products obtained by carrying out the processes described herein, in particular to downstream products like monomers, polymers, or polymer products as well as to any fractions and downstream products thereof.Further embodiments of the different aspects of the invention are described by the combination of any and each of the above definitions and embodiments with one another.Preferred Embodiments1 . A process to produce a diisocyanate, preferably selected from the group consisting of methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI), the process comprising step S5) S5) reacting a diamine with phosgene to obtain the diisocyanate, whereby at least a portion of said diamine is provided from step S4)S4) converting an unsaturated hydrocarbon to a diamine; whereby at least a portion of said unsaturated hydrocarbon is provided from step S3)S3) providing methanol and converting at least a portion of said methanol to an unsaturated hydrocarbon, preferably selected from the group consisting of benzene, toluene, and propylene; and whereby at least a portion of said phosgene is provided from step S2)S2) providing phosgene; wherein at least a portion of the phosgene provided in step S2) and / or at least a portion of the methanol provided in step S3) is provided from syngas provided in step S1)S1) providing syngas.2. A process to produce a diisocyanate, preferably selected from the group consisting of methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI), the process comprising step S5)240953W0014955) reacting a diamine with phosgene to obtain the diisocyanate, whereby at least a portion of said diamine is provided from step S4)S4) converting an unsaturated hydrocarbon to a diamine; whereby at least a portion of said unsaturated hydrocarbon is provided from step S3*)S3*) converting syngas to an unsaturated hydrocarbon, preferably selected from the group consisting of benzene, toluene, and propylene; whereby at least a portion of said syngas is provided from step S 1 )S1) providing syngas; and whereby at least a portion of said phosgene is provided from step S2)S2) providing phosgene; whereby optionally at least a portion of said phosgene is provided from syngas provided in step S 1 ).3. A process to produce at least one downstream product, preferably at least one product PRF1, more preferably selected from the group consisting of diisocyanate-derived polymers, the process comprising the process according to any of the preceding embodiments and further comprising step S6)56) converting the diisocyanate obtained in step S5) to the at least one downstream product. . The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from bio-based or recycling-based carbon-containing feedstocks. . The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from steam reforming or autothermal reforming of methane, optionally followed by water-gas shift reaction, wherein CO2 that is formed in the steam reforming or autothermal reforming process and / or in the optional water-gas shift reaction is captured and optionally stored and / or utilized.6. The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from gasification of plastic waste comprising diisocyanate-derived polymers.7. The process according to any of the preceding embodiments, wherein in step S 1 ), at least a portion of said syngas originates from pyrolysis of plastic waste comprising diisocyanate-derived polymers to obtain a pyrolysis oil, and subsequent partial oxidation and / or gasification of said pyrolysis oil.8. The process according to any of the preceding embodiments, wherein in step S2), at least a portion of said phosgene is provided by reaction of carbon monoxide with chlorine, wherein at least a portion of said carbon monoxide is obtained by separation from syngas provided in step S 1 ) and / or240953W00150 wherein at least a portion of said chlorine is obtained by hydrochloric acid electrolysis or by thermocatalytic gas phase oxidation of hydrogen chloride with oxygen, wherein at least a portion of said hydrochloric acid and hydrogen chloride, respectively, is provided from step S5).9. The process according to any of embodiments 1 and 3 to 8, wherein in step S3), providing methanol comprises the substepsS1) providing syngas; andS3b) converting at least a portion of said syngas to methanol.10. The process according to any of embodiments 1 and 3 to 9, wherein in step S3), said conversion to an unsaturated hydrocarbon comprises a methanol-to-aromatics step.11. The process according to any of embodiments 1 and 3 to 10, wherein in step S3), said conversion to an unsaturated hydrocarbon comprises a methanol-to-olefins process step or a methanol-to-propylene process step.12. The process according to any of embodiments 2 to 8, wherein in step S3*), during said conversion Fischer-Tropsch- type hydrocarbons are formed as intermediates or methanol is formed as an intermediate.13. The process according to any of the preceding embodiments, wherein in step S3) and S3*), respectively, said conversion comprises a hydrodealkylation of alkylated aromatics.14. The process according to any of the preceding embodiments, wherein step S4) comprises the nitration of an aromatic compound and the hydrogenation of the nitro group(s) or step S4) comprises the ammoxidation of an olefinic compound to obtain an a,|3-unsaturated nitrile, the dimerization of the nitrile to obtain a dinitrile, and hydrogenation of the dinitrile, wherein preferably at least a portion of the needed hydrogen is obtained by separation from syngas as provided in step S1)15. A system for producing a diisocyanate, the system comprising the unitsU1) syngas providing unit;U2) phosgene providing unit;U3) unsaturated hydrocarbon production unit;U4) diamine production unit; andU5) diisocyanate production unit.ExamplesThe following examples are for the purpose of illustration of the invention only and are not intended in any way to limit the scope of the present invention.240953W001511) Production of MDIMethylene diphenyl diisocyanate (MDI) is industrially produced from the main raw material benzene in four steps.Nitration of benzene with nitric acid to mono nitrobenzene (MNB)Hydrogenation of MNB to anilineCondensation reaction of aniline and formaldehyde (FAH) to methylenedianiline (MDA) Phosgenation of MDA to MDI with HCI as byproductThe MDI production network based on syngas or MeOH instead of crude oil is described below:Synthesis gas (“syngas”) utilized for the MeOH production can be generated from many different feedstocks, e.g. natural gas, coal, biomass, polymer waste, hydrogen (H2) and carbon dioxide (CO2). H2 as feedstock can be generated from electrolysis (NaCI or water as feedstock), CO2 as feedstock can be extracted from offgas streams of industrial processes or from the air by direct air capture (DAC). The technology utilized to produce syngas depends on the feedstock applied. Typical technologies for the production of syngas are gasification, partial oxidation, pyrolysis, steam methane reforming, dry reforming. If needed the molar ratio of H2 to CO in the syngas can be increased by applying water gas shift reaction in the syngas plant. On the other hand, by reaction of H2 with CO2 (reverse water gas shift reaction) the share of CO can be increased.For the production of MeOH from H2 and CO a molar ratio H2 / CO of 2 in the synthesis gas is most favorable. MeOH can also be produced from H2 and CO2 with water as byproduct at a molar ratio of 3.A part of the syngas generated to serve as feedstock for MeOH can be purified and separated in H2 and CO for downstream plants. Alternatively, the syngas for H2 and CO production can be delivered from a different source. There is also the possibility that hydrogen can be produced separately, e.g. by water electrolysis, ammonia cracking or methanol cracking.After separation and purification, the hydrogen can be used to produce ammonia, which is the precursor for nitric acid, and aniline by hydrogenation of MNB. The CO can be utilized as raw material for the synthesis of phosgene.The MeOH produced from the syngas serves as feedstock to produce FAH. In addition, benzene is produced from MeOH in an MTA (methanol-to-aromatics) plant. Formaldehyde is produced from oxidation of methanol (MeOH) with oxygen in the gas phase at solid catalyst (e.g. iron oxide in combination with molybdenum and / or vanadium). Phosgene is produced from chlorine and carbon monoxide (CO) in the gas phase at activated carbon as catalyst.During the condensation reaction of aniline and FAH, a mixture of 2-ring MDA isomers (4,4’-MDA, 2,4’-MDA, 2,2’-MD A) and MDA oligomers (MDA chains consisting of 3 and more phenyl rings) is formed. After phosgenation of the MDA mixture, a mixture of different 2-ring MDI isomers (4,4’-MDI, 2,4’-MDI, 2,2’-MDI) and MDI oligomers (MDI chains consisting of 3 and more phenyl rings) is obtained. In industrial processes, the MDI mixture is often separated in monomer and oligomer fractions by distillation or crystallization or a combination of both. Typical monomer fractions are 4,4’-MDI or a mixture of 4,4’-MDI and 2,4’-MDI sometimes containing also 2,2’-MDI. The oligomer fraction of the separation process usually contains a mixture of MDI oligomers and MDI monomers.The byproduct HCI of the phosgenation reaction can be absorbed in water to yield muriatic acid. In addition, it can be utilized as a gaseous raw material for ethylene dichloride (EDC) or vinyl chloride monomer (VCM) and subsequent PVC production. Finally, it can also be recycled back to chlorine by oxidation, either in the gas phase (Deacon process) or in the aqueous phase (HCI electrolysis with or without oxygen depolarized cathode).240953W00152All production plants of the MDI production network based on MeOH can be either located and connected with each other at one location or scattered over several different locations. Often site selection for certain production units is based on availability and prices for raw materials or utilities and logistics cost. E.g. , MeOH could be produced at one location where biomass for syngas production is readily available and then transported to another site where it is converted in an MTA plant to benzene. Similar, ammonia could be produced at one site where syngas or hydrogen are readily available and then transported to another site to be converted there to nitric acid. However, usually hydrogen production will be located at one location together with aniline production and CO production will be located at one location together with phosgene production because transportation of those gaseous raw materials is difficult and expensive. In addition, for safety reasons chlorine and phosgene production will usually be located at one location together with the phosgenation and the HCI conversion.2) Production of TDIToluene diisocyanate (TDI) is industrially produced from the main raw material toluene in three steps:Nitration of toluene with nitric acid to dinitrotoluene (DNT) Hydrogenation of DNT to diaminotoluene (TDA) Phosgenation of TDA to TDI with HCI as byproductThe TDI production network based on syngas or MeOH instead of crude oil is described below:The production and use of syngas, MeOH, H2, CO, and HCI are described for Example 1 and apply equally to Example 2. Also, the above-mentioned considerations regarding an MDI production site apply equally to TDI.Toluene is produced from MeOH in an MTA (methanol-to-aromatics) plant.In the technical process all six possible TDI isomers are formed, however only two of them (2,4-TDI, 2,6-TDI) are of commercial relevance. The unwanted isomers are usually removed in the workup section of the TDA step.

Claims

240953W00153Claims1 . A process to produce a diisocyanate, selected from the group consisting of methylene diphenyl diisocyanate (M DI) and toluene diisocyanate (TDI), the process comprising the steps S1); S2); one of S3) and S3*); S4); and S5):51) providing syngas;52) providing phosgene;53) converting at least a portion of said syngas to methanol and converting at least a portion of said methanol to an aromatic hydrocarbon selected from the group consisting of benzene and toluene;S3*) converting at least a portion of said syngas to an aromatic hydrocarbon selected from the group consisting of benzene and toluene;54) converting at least a portion of said aromatic hydrocarbon to a diamine;55) reacting at least a portion of said diamine with at least a portion of said phosgene to obtain the diisocyanate.

2. A process to produce at least one downstream product, preferably at least one product PRF1, more preferably selected from the group consisting of diisocyanate-derived polymers, the process comprising the process according to any of the preceding claims and further comprising step S6)56) converting the diisocyanate obtained in step S5) to the at least one downstream product.

3. The process according to any of the preceding claims, wherein in step S 1 ), at least a portion of said syngas originates from bio-based or recycling-based carbon-containing feedstocks.

4. The process according to any of the preceding claims, wherein in step S 1 ), at least a portion of said syngas originates from steam reforming or autothermal reforming of methane, optionally followed by water-gas shift reaction, wherein CO2 that is formed in the steam reforming or autothermal reforming process and / or in the optional water-gas shift reaction is captured and optionally stored and / or utilized.

5. The process according to any of the preceding claims, wherein in step S1 ), at least a portion of said syngas originates from gasification of plastic waste comprising diisocyanate-derived polymers.

6. The process according to any of the preceding claims, wherein in step S 1 ), at least a portion of said syngas originates from pyrolysis of plastic waste comprising diisocyanate-derived polymers to obtain a pyrolysis oil, and subsequent partial oxidation and / or gasification of said pyrolysis oil.

7. The process according to any of the preceding claims, wherein in step S2), at least a portion of said phosgene is provided from syngas of step S 1 ).

8. The process according to any of the preceding claims, wherein in step S2), at least a portion of said phosgene is provided by reaction of carbon monoxide with chlorine,240953W00154 wherein at least a portion of said carbon monoxide is provided by separation from syngas of step S1) and / or wherein at least a portion of said chlorine is obtained by hydrochloric acid electrolysis or by thermocatalytic gas phase oxidation of hydrogen chloride with oxygen, wherein at least a portion of said hydrochloric acid and hydrogen chloride, respectively, is provided from step S5).

9. The process according to any of the preceding claims, wherein in step S3), said conversion to an aromatic hydrocarbon comprises a methanol-to-aromatics step, a methanol-to-olefins process step, or a methanol-to-propylene process step.

10. The process according to any of the preceding claims, wherein in step S3*), during said conversion Fischer-Trop- sch-type hydrocarbons are formed as intermediates or methanol is formed as an intermediate.

11. The process according to any of the preceding claims, wherein in step S3) and S3*), respectively, said conversion comprises a hydrodealkylation of alkylated aromatics.

12. The process according to any of the preceding claims, wherein step S4) comprises the nitration of benzene to nitrobenzene or of toluene to dinitrotoluene and the hydrogenation of the nitro group(s) to obtain aniline and toluenediamine, respectively, wherein preferably at least a portion of the needed hydrogen is provided by separation from syngas of step S1).

13. The process according to the preceding claim, wherein step S4) further comprises the condensation of aniline with formaldehyde in the presence of hydrochloric acid and optionally the neutralization using sodium hydroxide, wherein at least a portion of said formaldehyde is provided from the oxidation of methanol of step S3).

14. A diisocyanate, selected from the group consisting of methylene diphenyl diisocyanate (MDI) and toluene diisocyanate (TDI), or a downstream product thereof, preferably a product PRF1 , more preferably selected from the group consisting of diisocyanate-derived polymers, wherein said diisocyanate or downstream product is produced according to any of the processes of the preceding claims, and wherein said diisocyanate or downstream product is characterized by net-negative carbon dioxide emissions.

15. A system for producing a diisocyanate, the system comprising the unitsU1) syngas providing unit;U2) phosgene providing unit;U3) aromatic hydrocarbon production unit;U4) diamine production unit; andU5) diisocyanate production unit.

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