patent claims

1. Method (100) for preparing a target compound, in which a first

Gas mixture is provided, the at least one olefin with a first

contains carbon number and carbon monoxide, wherein a second gaseous mixture formed using at least a portion of the first gaseous mixture and at least the olefin having the first carbon number, hydrogen and

Contains carbon monoxide to obtain a third gas mixture, the one

Compound having a second carbon number and containing at least carbon monoxide, is subjected to one or more reaction steps, wherein the one or more reaction steps comprises or comprise a hydroformylation (2), and wherein the second carbon number is one greater than the first carbon number, characterized in that that using at least part of the third gas mixture compared to the third gas mixture depleted in the compound with the second carbon number and on

carbon monoxide-enriched fourth gas mixture is formed, that the carbon monoxide in at least part of the fourth gas mixture is subjected to a water gas shift (3) with the formation of hydrogen and carbon dioxide, and that the hydrogen formed in the water gas shift is used at least in part to form the second gas mixture.

2. The method according to claim 1, in which the first gas mixture is provided using an oxidative coupling of methane (1) and contains at least ethylene as the olefin with the first carbon number and additionally at least methane, ethane and carbon dioxide, the carbon dioxide leaving behind the second gas mixture is at least partially separated from the first gas mixture or a part thereof.

3. The method as claimed in claim 1, in which the fourth gas mixture contains one or more paraffins, with a fifth gas mixture being formed in a separation (1 16) using at least part of the fourth gas mixture which, compared to the fourth gas mixture, has one or the several paraffins depleted and carbon monoxide enriched, the fifth

Gas mixture is supplied at least in part to the water-gas shift (3).

4. The method of claim 3, wherein in the separation (1-16) in which the fifth gaseous mixture is formed, a sixth gaseous mixture is further formed which is enriched in the one or more paraffins and depleted in carbon monoxide relative to the fourth gaseous mixture, wherein at least part of the sixth gas mixture is used in providing the first gas mixture.

5. The method (100) according to any one of the preceding claims, wherein the

Reaction steps in addition to the hydroformylation (2) comprise one or more further reaction steps, in which the one or more compounds having the second number of carbons form an aldehyde in the hydroformylation (2) and one or more further, in the one or more further subsequent steps compounds formed include.

6. The method (100) according to claim 5, in which the formation of the fourth gas mixture is carried out downstream of the one or more further subsequent steps.

7. The method (100) according to claim 5 or 6, in which the one or more further subsequent steps comprises or comprise a hydrogenation in which the aldehyde is reacted with hydrogen to form an alcohol.

8. The method (100) according to claim 7, in which the first gas mixture contains hydrogen and in which at least part of this hydrogen is used in the hydrogenation.

9. The method (100) according to any one of claims 5 to 8, wherein the one or the

several subsequent steps include or include a dehydration in which the alcohol is converted into an olefin.

10. The method (100) according to any one of claims 5 to 9, wherein a in the

Water gas shift (3) amount of hydrogen formed is adapted to a hydrogen requirement in the hydroformylation and/or hydrogenation.

1 1. The method (100) according to any one of the preceding claims, in which the olefin having the first carbon number and the carbon monoxide from the first gas mixture are fed at least partially unseparated from one another in the second gas mixture of the hydroformylation (2).

12. The method (100) according to any one of the preceding claims, wherein the first

Gas mixture is compressed to a first pressure level at which the

Hydroformylation (2) is carried out at a second pressure level, and in which the water-gas shift (3) is carried out at a third pressure level, the second pressure level being the highest of the pressure levels.

13. The method (100) according to any one of the preceding claims, downstream of the

Provision of the starting gas mixture and the water gas shift (3) is carried out completely non-cryogenically.

14. Plant for the production of a target compound, which is set up to provide a first gas mixture containing at least one olefin with a first

contains carbon number and carbon monoxide, a second gaseous mixture formed using at least a portion of the first gaseous mixture and at least the olefin having the first carbon number, hydrogen and

Contains carbon monoxide to obtain a third gas mixture, the one

Compound having a second carbon number and containing at least carbon monoxide, subjecting it to one or more reaction steps, wherein the one or more reaction steps comprises or comprise hydroformylation (2), and wherein the second carbon number is one greater than the first carbon number, characterized by means which are set up to use at least part of the third gas mixture to form a fourth gas mixture that is depleted in the compound with the second carbon number and enriched in carbon monoxide compared to the third gas mixture, the carbon monoxide in at least part of the fourth gas mixture to form hydrogen and to subject carbon dioxide to a water gas shift (3),and to use at least part of the hydrogen formed in the water gas shift in the formation of the second gas mixture.

15. Plant according to claim 14, which has a reactor arrangement for

is set up, the first gas mixture using an oxidative

Provide coupling of methane (1).

description

Process and plant for the production of a target compound

The present invention relates to a method for producing a target compound, in particular propylene, and a corresponding plant according to the preambles of the independent patent claims.

The project that led to the present patent application was funded under grant agreement No. 814557 of the European Union's Horizon 2020 research and innovation programme.

State of the art

The preparation of propylene (propene) is described in the specialist literature, for example in the article "Propylene" in Ullmann's Encyclopedia of Industrial Chemistry, 2012 edition. Propylene is conventionally produced by steam cracking (Steam

Cracking) of hydrocarbon feeds and conversion processes in the course of refinery processes. In the latter process, propylene will not

necessarily in the desired quantity and only as one of several

Components formed in a mixture with other compounds. Other

Processes for the production of propylene are also known, but they are not always satisfactory, for example in terms of efficiency and yield.

An increasing demand for propylene ("propylene gap") is forecast for the future, which requires the provision of corresponding selective processes. At the same time, it is important to reduce or even prevent carbon dioxide emissions. As a potential

On the other hand, large quantities of methane are available as feedstocks, which are currently only recycled to a very limited extent and are mostly burned.

The present invention has as its object a process for the production of propylene which is improved in particular in view of these aspects, but also for the production of other organic target compounds, in particular of

Oxo compounds such as aldehydes and alcohols with a corresponding

Carbon backbone to provide.

Disclosure of Invention

Against this background, the present invention proposes a method

Preparation of a target compound, in particular propylene, and a corresponding system with the respective features of the independent claims.

Preferred configurations of the present invention are the subject matter of the dependent patent claims and the following description.

Basically, in addition to the above-mentioned steam cracking processes, there are a large number of different processes for converting hydrocarbons and related compounds into one another, some of which will be mentioned below as examples.

For example, the conversion of paraffins to olefins of the same chain length by oxidative dehydrogenation (ODH, also referred to as ODHE in the case of ethane) is known. The production of propylene from propane by dehydrogenation (PDH) is also known and is a commercially available and established process. The same applies to the production of propylene from ethylene by olefin metathesis. This process requires 2-butene as an additional starting material.

Finally, there are so-called methane-to-olefin or methane-to-propylene processes (MTO, MTP) in which synthesis gas is first produced from methane and the synthesis gas is then converted into olefins such as ethylene and propylene. Corresponding methods can be based on methane, but also based on other hydrocarbons or carbonaceous

Starting materials such as coal or biomass are operated.

However, ethylene can also be produced by the oxidative coupling of methane (OCM). Because the oxidative coupling of methane is in a preferred

Embodiment of the present invention is used, it will first be explained in more detail below. The oxidative coupling of methane is described in the literature, for example by JD Idol et al., "Natural Gas", in: JA Kent (ed.), "Handbook of Industrial Chemistry and Biotechnology", Vol. 2, 12th edition, Springer , New York 2012. Basically within the scope of the present invention

processing of other gas mixtures, ie those not provided by the oxidative coupling, is possible and advantageous if these gas mixtures contain one or more olefins in a significant content, for example more than 10, 20, 30, 40 or 50 mole percent and up to 80 mole percent ( as an individual or cumulative value) and carbon monoxide in the same quantity ranges. When the present invention is described below with specific reference to the oxidative coupling of methane and ethylene formed in the oxidative coupling, this is not intended to be limiting.

According to the current state of knowledge, the oxidative coupling of methane comprises a catalyzed gas-phase reaction of methane with oxygen, in which two

One hydrogen atom is split off from each methane molecule. Oxygen and methane are activated on the catalyst surface. The emerging

Methyl radicals initially react to form an ethane molecule. A water molecule is also formed in the reaction. With suitable methane to oxygen ratios, suitable reaction temperatures and the choice of suitable ones

Under catalytic conditions, ethane is then oxydehydrogenated to ethylene, a target compound in the oxidative coupling of methane. Another water molecule is formed. The oxygen used is typically completely converted in the reactions mentioned.

The reaction conditions in the oxidative coupling of methane classically involve a temperature of 500 to 900 °C, a pressure of 5 to 10 bar and high space velocities. More recent developments are also moving in the direction of using lower temperatures. The reaction can take place with homogeneous or heterogeneous catalysis in a fixed bed or in a fluidized bed. During the oxidative coupling of methane, higher hydrocarbons with up to six or eight carbon atoms can also be formed, but the focus is on ethane or ethylene and possibly also propane or propylene.

In particular, due to the high binding energy between carbon and

With hydrogen in the methane molecule, the yields in the oxidative coupling of methane are comparatively low. Typically, no more than 10 to 15% of the methane used is converted. In addition, the comparatively harsh reaction conditions and temperatures favor the cleavage of these

Bonds are required, as well as further oxidation of the methyl radicals and other intermediates to carbon monoxide and carbon dioxide. In particular, the use of oxygen plays a dual role here. So is the methane conversion from the

oxygen concentration in the mixture. The formation of by-products is coupled with the reaction temperature, since the total oxidation of methane, ethane, and ethylene occurs preferentially at high temperatures.

Although the low yields and the formation of carbon monoxide and

Carbon dioxide can be partially counteracted by the choice of optimized catalysts and adapted reaction conditions, a gas mixture formed in the oxidative coupling of methane contains, in addition to the target compounds such as ethylene and possibly propylene, predominantly unreacted methane as well as carbon dioxide, carbon monoxide and water. Considerable amounts of hydrogen can also be present as a result of non-catalytic cleavage reactions that may take place. In the language used here, such a gas mixture is also referred to as a "product mixture" of the oxidative coupling of methane, although it predominantly does not contain the desired products, but also the unreacted starting material methane and the by-products just explained.

In the case of the oxidative coupling of methane, reactors can be used in which a catalytic zone is followed by a non-catalytic zone. The gas mixture flowing out of the catalytic zone is transferred to the non-catalytic zone, where it is initially still at the comparatively high temperatures used in the catalytic zone. In particular due to the presence of the water formed during the oxidative coupling of methane, the reaction conditions here are similar to those of conventional steam cracking processes. Therefore, ethane and higher paraffins can be converted to olefins here. Further paraffins can also be fed into the non-catalytic zone, so that the residual heat from the oxidative coupling of methane can be utilized in a particularly advantageous manner.

Such targeted steam cracking in one of the catalytic zones

downstream non-catalytic zone is also referred to as "post bed cracking". The term “post-catalytic steam cracking” is also used for this below. The following is the speech that a used according to the invention

If the starting gas mixture is formed or provided “using” or “using” an oxidative coupling of methane, this information should not be understood in such a way that only the oxidative coupling itself has to be used in the provision. Rather, from the provision of the starting gas mixture, further process steps, in particular

post-catalytic steam cracking.

According to particularly preferred embodiments of the present invention, paraffins, in particular ethane, which are separated off from any material streams at a suitable point or can be contained in corresponding material streams, can be recycled alone or together with other components for the post-catalytic steam cracking. The separation, if undertaken, takes place at a point that is suitable from a technical separation point of view, that is to say at a position at which the separation is particularly inexpensive and, in particular, non-cryogenically possible. If in the following it is mentioned that ethane or another paraffin besides methane is "returned to the process", this can in particular mean a return to the post-catalytic steam cracking. methane that is "recycled to the process"

However, recycling can also take place together and in particular together with carbon monoxide in the overall oxidative coupling.

Hydroformylation represents a further technology which is used in particular for the production of oxo compounds of the type mentioned at the outset.

Propylene is typically reacted in the hydroformylation, but higher hydrocarbons, in particular hydrocarbons having six to eleven carbon atoms, can also be used. In principle, the reaction of hydrocarbons with four and five carbon atoms is also possible, but of less practical importance. Hydroformylation, in which aldehydes can initially be formed, can be followed by hydrogenation. Alcohols formed by such a hydrogenation can then be dehydrated to the respective olefins.

In Green et al., Catal. Latvia 1992, 13, 341 describes a process for the production of propanal from methane and air. In principle, low yields based on methane are recorded in the process presented. In which

Methods involve oxidative coupling of methane (OCM) and partial oxidation of methane (POX) to hydrogen and carbon monoxide, followed by hydroformylation. The target product is the propanal mentioned, which has to be isolated as such. A limitation results from the oxidative coupling of methane to ethylene, for which currently only lower conversions and limited selectivities are typically achieved. Differences in Green et al. described methods of the present invention are explained below with reference to the advantages attainable according to the invention.

The hydroformylation reaction in the process just mentioned is carried out over a typical catalyst at 1×15° and 1 bar in an organic solvent. The selectivity to the (undesirable) by-product ethane is in the range of about 1% to 4%, whereas the selectivity to propanal should reach more than 95%, typically more than 98%. Extensive integration of

Process steps or the use of the carbon dioxide formed in large quantities as a by-product, in particular in the oxidative coupling of methane, is not described further here, so that there are disadvantages compared to conventional processes. Because the partial oxidation is used as a downstream step for the oxidative coupling in the process, i.e. there is a sequential connection, large amounts of unreacted methane from the oxidative coupling have to be dealt with in the partial oxidation or separated at great expense.

In US Pat. No. 6,049,011 A is a process for the hydroformylation of ethylene

described. The ethylene can be formed in particular from ethane. as

In addition to propanal, the target product can also be produced with propionic acid. Dehydration is also possible. However, this publication also does not disclose any further integration and does not disclose any meaningful use of the carbon dioxide formed.

In the water gas shift reaction (WGSR), carbon monoxide is reacted with water vapor to form carbon dioxide and hydrogen. It is an exothermic equilibrium reaction, with

In the opposite direction, hydrogen can also be converted with carbon dioxide to form carbon monoxide and water (Reversed Water Gas Shift, RWGS). Details can be found, for example, in the articles "Hydrogen, 2nd Production" and "Synthesis Gas" in Ullmann's Encyclopedia of Industrial Chemistry. In the water gas shift, a distinction is made between low and high temperature processes (Low Temperature Shift, LTS, and High Temperature Shift, HTS).

For high-temperature processes can in particular iron or

Chromium oxide catalysts are used, which are charged with an input gas at approx. 350 °C. The temperature rises to 400 to 450 °C due to the exothermic nature of the shift reaction. In order to avoid excessively high outlet temperatures, the inlet temperature is limited accordingly. at

In low temperature processes, the feed gas temperature is around 220°C and carbon dioxide removal is typically envisaged. For

Low-temperature processes typically use copper, zinc and aluminum mixed oxides with promoters (eg with traces of potassium).

A commercial catalyst for a high temperature process comprises

for example, about 74.2% diiron trioxide, 10.0% dichromium trioxide, 0.2% magnesium oxide and volatile components in the remainder. The chromium oxide acts to

Stabilization of the iron oxide and prevents sintering. High-temperature reactors used on an industrial scale operate in a range of

Atmospheric pressure up to approx. 8 MPa.

The typical composition of a commercial catalyst for a

Low temperature process is 32 to 33% copper oxide, 34 to 53% zinc oxide, 15 to 33% diallumina trioxide. The active catalytic species is copper oxide and the function of the zinc oxide is to prevent copper from being poisoned by sulfur. The dialuminum trioxide prevents dispersion and pellet shrinkage. The upper temperature limit for low-temperature processes results from the susceptibility of copper to thermal sintering. These lower temperatures also reduce the occurrence of side reactions.

In principle, within the scope of the present invention, high and low-temperature processes can be used for the water-gas shift. These are based in particular on the available or usable amounts of heat.

For example, in the optionally used oxidative coupling, a large amount of heat of the product mixture formed at high temperatures

for example, to preheat the insert in a high-temperature process.

Advantages of the Invention

Against this background, the present invention proposes a method

Production of a target compound, in particular of propylene, in which a first gas mixture is provided, the at least one olefin with a first

contains carbon number and carbon monoxide. In the context of the present invention, it can be provided in particular that methane is subjected to an oxidative coupling with oxygen to obtain ethylene and other components, including the carbon monoxide mentioned, but also any unreacted methane and ethane and carbon dioxide. The first gas mixture represents a starting mixture which is further processed within the scope of the present invention to produce the target compound. Depending on how it is provided, the first gas mixture can also contain water. Hydrogen can also be contained in the first gas mixture. However, the presence of hydrogen and other components is not

A prerequisite, even if a corresponding first gas mixture is described below as containing hydrogen or containing other components. The oxidative coupling can also be carried out, for example, without the presence or formation of hydrogen. As mentioned several times, it is not

necessarily subject matter of the invention, but provided in an embodiment.

As already mentioned at the outset, the oxidative coupling of methane is a process which is fundamentally known from the prior art. In the context of the present invention, known for the oxidative coupling of methane

Process concepts are used.

In embodiments of the present invention, (substantially) pure methane or natural gas or

Associated gas fractions of different purification stages up to the corresponding raw gas can be used. For example, natural gas can also be fractionated, where if an oxidative coupling is used, methane in the oxidative

Coupling itself and higher hydrocarbons can preferably be performed in a post-catalytic steam cracking. Oxygen is particularly preferred as the oxidizing agent in a corresponding process. In principle, air or oxygen-enriched air can also be used, but lead to an

Nitrogen entry into the system. Separation at a suitable point in the process would in turn be comparatively expensive and would have to be carried out cryogenically.

In the embodiments of the present invention in which it is used, a dilution medium, preferably steam, but also, for example, carbon dioxide, can be used in the oxidative coupling, in particular to moderate the reaction temperatures. Carbon dioxide can also (partially) serve as an oxidizing agent. Compounds such as nitrogen, argon and helium, which are in principle also suitable as diluents, in turn require complex separation. With the current state of the technology, however, recirculated methane in particular serves as a diluent, of which only a comparatively small proportion is converted.

In configurations of the present invention, the oxidative coupling can be carried out in particular at an overpressure of 0 to 30 bar, preferably 0.5 to 5 bar, and a temperature of 500 to 1100° C., preferably 550 to 950° C. In principle, catalysts known from the technical literature can be used, see for example Keller and Bhasin, J. Catal. 1982, 73, 9, Hinsen and Baerns, Chem. Ztg. 1983, 107, 223, Kondratenko et al., Catal. May be. technol. 2017, 7, 366-381. Farrell et al., ACS Catalysis 6, 2016, 7, 4340, Labinger, Catal. Latvia 1 , 1988, 371, and Wang et al., Catalysis Today 2017, 285, 147.

In the context of the present invention, the conversion of methane in the oxidative coupling can in particular be more than 10%, preferably more than 20%, particularly preferably more than 30% and in particular up to 60% or 80%. The particular advantage of the embodiments of the present invention, in which an oxidative coupling is used, lies not primarily in the increased yield, but in the fact that, in addition to, in particular, a relatively high relative proportion of carbon monoxide in relation to ethylene in the product mixture of the oxidative coupling, i.e. the first gas mixture used in the context of the present invention, and that this can be operated in a yield-optimized manner through the use of a water-gas shift, as explained below.

Typical by-products of the oxidative coupling of methane are carbon monoxide and carbon dioxide, which are formed in the low to double-digit percentage range. A typical product mixture of the oxidative coupling of methane within the meaning of the invention has, for example, the following mixture proportions:

hydrogen 0.1 to 10 mole percent

Methane 20 to 90 mole percent

ethane 0.5 to 30 mole percent

ethylene 5 to 50 mole percent

Carbon monoxide 5 to 50 mole percent

Carbon dioxide 0.5 to 30 mole percent

This information relates to the dry portion of the product mixture, which can also contain water vapor in particular. Other components such as higher hydrocarbons and aromatics can typically be present in concentrations of less than 5 mole percent, in particular less than 1 mole percent. especially less than 0.1 mole percent, may be present in the oxidative coupling product mixture.

As already mentioned several times, the first gas mixture provided within the scope of the present invention can also be formed by other methods, or other methods can be involved in its formation. The composition of the gas mixture can in particular be as described above for the product mixture of the oxidative coupling, but can also deviate from this.

In the context of the present invention, a second gas mixture, which is formed using at least part of the first gas mixture and contains at least the olefin with the first carbon number, hydrogen and carbon monoxide, to obtain a third gas mixture which contains a compound with a second carbon number and at least contains carbon monoxide, one or more

Reaction steps, which or which includes or include a hydroformylation, subjected. Both the first and the second gas mixture can also

contain carbon dioxide. Carbon dioxide can be formed in particular in the case of an oxidative coupling of methane, but it can also originate from other processes and in this way get into the first and/or second gas mixture. For example, carbon dioxide is also formed in the water gas shift according to the invention. Forming the second gaseous mixture using at least a portion of the first

Gas mixture can in particular also include the separation of carbon dioxide from the first gas mixture or part thereof, with the remainder being used partially or completely to form the second gas mixture. Carbon dioxide can also be separated off at a suitable point further downstream. As explained below, the formation of the second gas mixture always also includes the addition of hydrogen from a water gas shift used according to the invention.

If the oxidative coupling is used, but also in other cases, the first gas mixture also contains unreacted methane and/or ethane and/or higher hydrocarbons, in particular paraffins. Hydrogen can also be included. In addition to the carbon monoxide, the third gas mixture can also have other components, in particular secondary compounds, in the one or more

Implementation steps are formed, included. Compounds, for example paraffins such as methane and/or ethane, can also get into the third gas mixture from the first gas mixture without being converted in the one or more conversion steps.

The second carbon number is one greater than the first due to the hydroformylation reaction that is part of the one or more reaction steps

carbon count. For example, when oxidative coupling is used, the first-carbon olefin is ethylene and the second-carbon compound is propanal, propanol, and/or propylene.

As explained below, a total of two, three (or more)

Implementation steps may be provided, comprising the hydroformylation and subsequently to a hydrogenation and optionally additionally a dehydration. In each of these steps, a compound with the second carbon number (e.g. three carbon atoms) is formed, in the form of an aldehyde (e.g. propanal) in hydroformylation, in the form of an alcohol in hydrogenation

(e.g. propanol) from the aldehyde, and in the dehydration in the form of an olefin (e.g. propylene) from the alcohol. When using several reaction steps, the third gas mixture can therefore be a product mixture of each of these

Be implementation steps, so a product mixture from the hydroformylation, a product mixture from the hydrogenation or a product mixture from the

dehydration. In each case, it cannot be ruled out that further reaction steps will follow the formation of the third product mixture

are made or that only the implementation steps mentioned and not further implementation steps or other processing steps such as a

cleaning, separation, drying or the like are carried out.

Hydroformylation processes are also known in principle from the prior art. Recently, Rh-based catalysts have typically been used in corresponding processes, as described in the literature cited below. Older processes also use Co-based catalysts.

For example, homogeneous, Rh(I)-based catalysts with phosphine and/or phosphite ligands can be used. These can be monodentate or bidentate complexes. Be used for the production of propanal

typically reaction temperatures of 80 to 150°C and corresponding

catalysts used. All methods known from the prior art can also be used within the scope of the present invention.

The hydroformylation typically operates with a 1:1 ratio of hydrogen to carbon monoxide. In principle, however, this ratio can be in the range from 0.5:1 to 10:1. The Rh-based catalysts used can have a Rh content of 0.01 to 1.00 percent by weight, the ligands in the

excess may be present. More details are in the article "Propanal" in

Ullmann's Encyclopedia of Industrial Chemistry, 2012 edition. The invention is not limited by the process conditions mentioned.

In another process, as described, for example, in the "Hydroformylation" chapter by Moulijn, Makee & van Diepen, Chemical Process Technology, 2012, 235, a pressure of 20 to 50 bar is used with a Rh-based catalyst and a pressure of 20 to 50 bar with a Co -based catalyst used a pressure of 70 to 200 bar. Co also appears to be relevant for hydroformylation in its metallic form. Other metals are more or less unimportant, especially Ru, Mn and Fe. The temperature range used in the process mentioned is between 370 K and 440 K.

In the process disclosed in the chapter "Synthesis involving carbon monoxide" in Weissermel & Arpe, Industrial Organic Chemistry 2003, 135, mainly Co and Rh phosphine complexes are used. With specific ligands, the

Hydroformylation can be carried out in the aqueous medium and the recovery of the catalyst is easily possible.

According to Navid et al., Appl. Catal. A 2014, 469, 357, everyone can in principle

Transition metals capable of forming carbonyls are used as potential hydroformulation catalysts, with activity observed according to this publication according to Rh>Co>Ir, Ru>Os>Pt>Pd>Fe>Ni.

By-products in the hydroformylation are formed in particular by the

Hydrogenation of the olefin to the corresponding paraffin, eg from ethylene to ethane, or the hydrogenation of the aldehyde to the alcohol, ie from propanal to propanol. According to the article "Propanols" in Ullmann's Encyclopedia of Industrial Chemistry, 2012 edition, propanal formed by hydroformylation can be used as the main source of 1-propanol in industry. In a second step, propanal can be hydrogenated to 1-propanol.

In general, regardless of the specific type, sequence and number of the reaction steps mentioned in the context of the present invention, a fourth gas mixture which is depleted in the compound with the second carbon number and enriched in carbon monoxide compared to the third gas mixture is formed, at least using at least part of the third gas mixture. This formation of the fourth gas mixture can in particular a non-cryogenic separation of

Include compound with the second carbon number, so that lower-boiling compounds remain in the fourth gas mixture. Such a separation is particularly simple in the case of the preparation of an aldehyde or alcohol as the compound with the second carbon number due to the comparatively high boiling point. The separation of a corresponding olefin with the second number of carbons, for example propylene, from lower-boiling compounds is also comparatively simple in terms of separation technology. Depending on the

Depending on the composition of the third gas mixture, the fourth gas mixture can therefore have, in particular, hydrogen, possibly carbon dioxide, methane, ethane and possibly residues of ethylene. Other lower-boiling compounds that are formed in the one or more reaction steps, for example as by-products, can also be present. In addition to connecting with the second

If necessary, other compounds with the second carbon number and higher-boiling compounds remain in a corresponding radical if they are formed.

If it is mentioned here that liquids or gases or corresponding mixtures are rich or poor in one or more components, "rich" should mean a content of at least 90%, 95%, 99%, 99.5%, 99.9 %, 99.99% or 99.999% and "poor" means a content of not more than 10%, 5%, 1%, 0.1%, 0.01% or 0.001% on a molar, weight or volume basis. The term "predominantly" means a content of at least 50%, 60%, 70%, 80% or 90% or corresponds to the term "rich". In the language used here, liquids and gases or corresponding mixtures can also be enriched or depleted in one or more components, these terms referring to a corresponding content in a starting mixture. The liquid or gas or mixture is " 1-fold, 0.01-fold or 0.001-fold content of a corresponding component, based on the starting mixture, is present. In this sense, a (theoretically possible) complete separation represents a depletion to zero with respect to a component in one fraction of a starting mixture, which therefore completely passes into the other fraction and is present there in enriched form. This is also covered by the terms "enrichment" and "depletion". 1-fold, 0.01-fold or 0.001-fold content of a corresponding component, based on the starting mixture, is present. In this sense, a (theoretically possible) complete separation represents a depletion to zero with respect to a component in one fraction of a starting mixture, which therefore completely passes into the other fraction and is present there in enriched form. This is also covered by the terms "enrichment" and "depletion".

If we are talking about a separation taking place, a mere enrichment of certain material flows in corresponding components or a depletion of other components can also take place at any time. All technologies known to the person skilled in the art can be used here, for example absorptive or adsorptive processes, membrane processes and enrichment or separation steps based on organometallic frameworks.

As mentioned, in embodiments of the present invention, a

Flydration and optionally a dehydration and / or further reaction steps of the components formed in the hydroformylation, here the aldehyde, for

production of other products. Each of these products can have a

Represent the target compound of the method proposed according to the invention.

The hydrogenation of different unsaturated components is a well-known and established technology for the conversion of components with a

Double bond in the corresponding saturated compounds. Typically, very high or complete conversions with selectivities of well over 90% can be achieved. Typical catalysts for the hydrogenation of

Carbonyl compounds are based on Ni, as also for example in the article

"Hydrogenation and Dehydrogenation" in Ullmann's Encyclopedia of Industrial

Chemistry, 2012 edition. Noble metal catalysts can also be used specifically for olefinic components. Hydrogenation is one of the standard reactions in technical chemistry, as for example in M. Baerns et al., "Example 11.6.1: Hydrogenation of double bonds", Technische Chemie 2006,

439, shown. In addition to unsaturated compounds (this refers in particular to olefins), the authors also mention other groups of substances, such as in particular aldehydes and ketones, as substrates for a hydrogenation. Low-boiling substances such as butyraldehyde from hydroformylation are hydrogenated in the gas phase. as

Here, Ni and certain noble metals such as Pt and Pd, typically in supported form, are used as hydrogenation catalysts.

For example in the article "Propanols" in Ullmann's Encyclopedia of Industrial

Chemistry, 2012 edition, describes a heterogeneous gas-phase process which is carried out at 110 to 1500 and a pressure of 0.14 to 1.0 MPa at a ratio of hydrogen to propanal of 20:1. Reduction occurs with excess hydrogen and the heat of reaction is removed by circulating the gas phases through external heat exchangers or by cooling the reactor internally. The efficiency based on hydrogen is more than 90%, the conversion of the aldehyde is up to 99.9% and there are

Alcohol yields greater than 99%. Commonly used commercial catalysts include combinations of Cu, Zn, Ni and Cr supported on alumina or kieselguhr. Dipropyl ether, ethane and propyl propionate are mentioned as typical by-products that may be produced in trace amounts. According to the general state of the art, the hydrogenation is preferably carried out in particular only with

stoichiometric amounts of hydrogen or only a small amount

excess hydrogen.

Details for corresponding liquid-phase processes are also given in the literature. These are carried out, for example, at a temperature of 95 to 12°C and a pressure of 3.5 MPa. Typically preferred as catalysts are Ni, Cu, Raney-Ni or supported Ni catalysts reinforced with Mo, Mn and Na. For example, 1-propanol can be produced with 99.9% purity. The main problem in the purification of 1-propanol is the removal of water from the product. If, as in one embodiment of the present invention, propanol is dehydrated to propylene, water is also one of the in this step

Reaction products are, so that no water must be removed in advance. The separation of propylene and water is therefore easy.

The dehydration of alcohols over suitable catalysts to produce the corresponding olefins is also known. In particular, the production of ethylene (from ethanol) is common and is gaining ground in connection with the

increasing production volumes of (bio)ethanol. The commercial application has been realized by different companies. For example, reference is made to the already mentioned article "Propanols" in Ullmann's Encyclopedia of Industrial Chemistry and Intratec Solutions, "Ethylene Production via Ethanol Dehydration", Chemical Engineering 120, 2013, 29. According to this, the dehydration of 1- or 2-propanol to propene has hitherto had no practical value. Nevertheless, the dehydration of 2-propanol is very easy to carry out in the presence of mineral acid catalysts at room temperature or above. The reaction itself is endothermic and equilibrium limited. High conversions are favored by low pressures and high temperatures. Typically, heterogeneous catalysts based on Al2 O 3 or SiO 2 is used. In general, several types of acidic catalysts are suitable, and molecular sieves and zeolites, for example, can also be used. Typical temperatures are in the range of 200 to 250°C for the dehydration of ethanol or 300 to 400°C for the

Dehydration of 2-propanol or butanol. Due to the

Equilibrium limitation, the product stream is typically separated

(Removal of the olefin product and also at least part of the water by, for example, distillation) and the stream containing the unconverted alcohol is used for

Reactor inlet recycled. In this way, a total of very high

Selectivities and yields can be achieved.

In the context of the present invention, carbon monoxide in at least part of the fourth gas mixture is subjected to a water gas shift to form hydrogen and carbon dioxide. Separation or enrichment can take place upstream of this water-gas shift, as will also be explained below. According to the invention, hydrogen formed in the water-gas shift is used at least in part in the formation of the second gas mixture and is thus supplied to the one or at least one of the several conversion steps.

The present invention thus proposes a total of (at least) the coupling of a hydroformylation process and a water gas shift, the

Hydroformylation and optionally subsequent process steps is or are fed with hydrogen which is formed in the water gas shift, the water gas shift carbon monoxide being fed from downstream of the hydroformylation, ie from the third or via the fourth gas mixture. One embodiment of the invention includes the provision of the first gas mixture by an oxidative coupling of methane.

Particular advantages result in the context of the present invention from the fact that hydrogen can be provided as required as the starting material by the water gas shift with the carbon monoxide from the third or fourth gas mixture. This is a main aspect of the present invention. In the oxidative coupling of methane, in which carbon monoxide and carbon dioxide are inevitably formed as by-products, no consideration needs to be given to the formation of these components due to the adjustability of these components due to the water gas shift, but the oxidative coupling can be yield-optimized conditions are operated. A corresponding embodiment of the present invention is therefore particularly advantageous.

In general, a particular advantage within the scope of the present invention also consists in the fact that components from the first or second gas mixture can be used in the hydroformylation and any subsequent reaction steps without complex cryogenic separation steps. In particular, any formed and / or existing paraffins and any methane that may be present from the first or second

Gas mixture carried along in the hydroformylation and then separated off more easily, or hydrogen, which is optionally present in the first or second gas mixture, can be used in addition to the hydrogen from the water gas shift for later hydrogenation steps. In this way, paraffins and methane can easily be recycled and reused in a reaction feed, as discussed previously with reference to the oxidative coupling and the

post-catalytic vapor cracks explained. Carbon dioxide can from the first

Gas mixture or part thereof separated and obtained in any purity. But as mentioned, there is also a separation further downstream, so

for example from the second or third gas mixture or a part thereof. Conversely, target components from the third gas mixture or subsequent mixtures thereof can be easily separated from the lower-boiling compounds mentioned due to the comparatively high boiling points.

In one embodiment, the present invention can also include that the carbon dioxide, which was separated from the first gas mixture or further downstream and was previously formed as a by-product in the oxidative coupling, is converted in any process step, for example also a dry reforming. In dry reforming, at least some of the corresponding carbon dioxide is reacted with methane to give carbon monoxide and/or hydrogen.

Through the use of the water-gas shift, the present invention enables precise adaptation of the respective hydrogen and/or carbon monoxide contents to the respective requirement for corresponding components in the hydroformylation or downstream process steps, such as hydrogenation.

The present invention enables an increase in the possible yield of valuable products, for example, the oxidative coupling through the use of

Carbon monoxide as a reactant in the hydroformylation and in the

water gas shift. At the same time, within the scope of the present invention, the effort involved in product purification and separation is reduced, in particular by avoiding cryogenic separation steps. The separation of C2 and C3 components in particular can take place at comparatively moderate temperatures and, if necessary, with avoidance of drying. Overall, the energy efficiency is improved and large cycles, which are conventionally required due to the limited conversions in the oxidative coupling, are avoided or minimized. Steps that do not add value, such as methanation, are avoided within the scope of the present invention, as is the formation of by-products and by-products, as in other processes for the production of target products, such as propylene.

In the aforementioned Green et al. already described the synthesis of propanal from methane and air, with an overall low yield based on methane being reported. In this process, a combination of oxidative methane coupling and partial oxidation is used, followed by one

hydroformylation. The target product is propanal, which must be isolated as such. Limitations here are the oxidative coupling of methane to ethylene, for which only low conversions and limited selectivities can be achieved even today. A further integration of process steps is given by Green et al. not described. The advantages that can be achieved according to the invention are therefore not given here. A Green et al. The above scheme lists partial oxidation as a downstream unit for oxidative coupling. Due to this sequential connection, large amounts of methane have to be dealt with in the partial oxidation, which are not converted in the oxidative coupling. The present invention overcomes corresponding disadvantages through the proposed measures.

In Green et al. a water gas shift is not mentioned at any point, but only a recirculation of carbon dioxide in a total recycling for partial oxidation is indicated. In this case, it is proposed to cryogenically separate ethylene, carbon dioxide and water from a product stream so that a residue containing methane, carbon monoxide and hydrogen remains. This cannot be implemented in practice, since when carbon dioxide and/or water is cryogenically separated, solid carbon dioxide and/or ice will cause very rapid displacement.

In addition to the missing statements on a water gas shift, statements on a corresponding carbon monoxide recycling can be found in Green et al. not either. Only a carbon monoxide recycling via a partial oxidation in the beginning of the hydroformylation is outlined.

As mentioned, in a method for providing the

Output gas mixture, for example in the oxidative coupling, more

By-products are formed. If appropriate, these can be removed, for example together with water of reaction, if appropriate by condensation and/or water washing from a corresponding product mixture of the oxidative coupling and thus from the first gas mixture.

Carbon dioxide, due to its high level of interaction with suitable

Solvents or washing liquids are also relatively easy to remove from the product mixture, with known methods for

Carbon dioxide removal, in particular appropriate washes (e.g. amine washes) can be used. Cryogenic separation is not required, so that the entire process of the present invention, at least including the hydroformylation, does not require cryogenic separation steps. If subsequent steps require the absence or only a very low residual concentration of carbon dioxide (e.g. due to catalyst inhibition or poisoning), the residual carbon dioxide content after an amine wash can be further reduced by an optional caustic wash as fine cleaning, as required.

Any hydrous ones occurring within the scope of the present invention

Gas mixtures can be subjected to drying at a suitable point in each case. For example, drying can take place downstream of the hydroformylation if, in one embodiment of the present invention, this takes place in the aqueous phase and the hydrogenation downstream of the hydroformylation requires a dry stream as reaction feed. If this is not necessary for the subsequent process steps, the drying does not have to be carried out to complete dryness, but water contents can also remain in the corresponding gas mixtures, provided these are tolerable. Different drying steps can also be provided at different points in the process and possibly with different degrees of drying.

The by-products just mentioned are separated off in an advantageous manner in a completely non-cryogenic manner and are therefore extremely simple in terms of apparatus and energy consumption. This represents a significant advantage of the present invention over prior art methods which

typically require a laborious separation of components which are undesirable in subsequent process steps.

A “non-cryogenic” separation is to be understood as meaning a separation or a separation step which takes place in particular at a temperature level above 0°C, in particular at typical cooling water temperatures of 5 to 40°C, in particular 5 to 25°C , is carried out, possibly also above

ambient temperature. In particular, however, a non-cryogenic separation in the sense understood here represents a separation without the use of a C2 and/or C3 cooling circuit and it therefore takes place above -30°C, in particular above -20°C.

A corresponding first gas mixture typically does not have components other than the olefin if it originates from an oxidative coupling

converted methane, ethane and carbon monoxide. Corresponding components can, however, also come from other processes, as mentioned. These compounds can be converted into the subsequent hydroformylation without problems. Paraffins such as methane and ethane are typically not converted in the hydroformylation. Since in the hydroformylation heavier compounds with higher

Boiling point or other polarity are formed, these can be comparatively simple and also non-cryogenic from the remaining lower boiling ones

components are separated. Instead of a complete separation, it is also possible for certain streams of substances to be enriched in the corresponding components or depleted in other components. All technologies known to the person skilled in the art can be used here, for example absorptive or adsorptive processes, membrane processes and enrichment or separation steps based on organometallic frameworks. As mentioned, at least the carbon monoxide thereof is converted in the water gas shift and the hydrogen formed can be fed to the hydroformylation or to subsequent conversion steps such as the hydrogenation.

In particular, methane and ethane, or more generally one or more paraffins, can be returned to the process in embodiments of the invention, for example to the oxidative coupling that may be used at the points mentioned, or also to other process steps. Ethane does not necessarily have to be returned to a separate reactor section for post-catalytic steam cracking, but can also be returned to the total oxidative coupling unseparated from the methane. Before that, however, there is a separation into a carbon monoxide fraction and a fraction that contains methane and ethane or the one or more paraffins.