Method and apparatus for preparing one or more synthetic products

Abstract

The invention relates to a process (100) for producing one or more synthesis products, in which process ethane is subjected to oxidative dehydrogenation (110) as a first feedstock compound in a first feedstream (11) to obtain a first product stream (12) containing ethylene as a first product olefin, and subjecting a second feedstock compound comprising oxygen and carbon to one or more catalytic conversion steps (210) in a second feedstream (21) to obtain a second product stream (22) comprising the first and / or second product olefins. In this case, it is provided that at least part of the first product stream (12) is passed through one or more first purification and / or separation steps (310) in order to obtain a first subsequent stream (13, 14) and that at least part of the second product stream (21) is not passed through one or more second purification and / or separation steps (310) in order to obtain a second subsequent stream (22, 23), and using at least part of the first subsequent stream (13, 14) and at least part of the second subsequent stream (22, 23) to form a third feed stream, wherein the third feed stream is supplied to one or more third purification and / or separation steps (310). The one or more first purification and / or separation steps (130) include only partial removal of carbon dioxide or no removal of carbon dioxide. The invention further provides a corresponding device.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for preparing one or more synthesis products. Background Art

[0002] Traditionally, most of the industrially produced ethylene and propylene is obtained by steam cracking in steam crackers. However, steam cracking is extremely energy-intensive and traditionally relies on the use of fossil feedstocks such as ethane, propane, liquefied petroleum gas (LPG), naphtha or higher hydrocarbon fractions. In addition, depending on the feedstock, steam cracking usually produces a certain proportion of other components that may be undesirable, such as aromatics.

[0003] In view of this, alternative processes for the production of olefins are becoming increasingly important. These alternative processes include selective processes such as oxydehydrogenation (ODH), which, in the case of ethane as feedstock, produces ethylene very selectively, in addition to a certain degree of co-production of the equally valuable acetic acid. Processes for the production of olefins based on other feedstocks are also known. This relates, for example, to the preparation of products of the Fischer-Tropsch synthesis, in particular the Fischer-Tropsch to Olefins (FTTO or FTO), which uses synthesis gas as feedstock, the conversion of methanol or dimethyl ether to olefins or propene (MTO or MTP), which uses the corresponding compounds as feedstock, or the hydrogenation of feedstreams containing CO2. Methanol and dimethyl ether themselves can also be produced from synthesis gas or feedstreams containing CO2.

[0004] However, the above-mentioned alternative olefin production processes (except ODHE) result in a broad product distribution, in which the focus is generally on the production of olefins with three carbon atoms, while compounds with two carbon atoms (ethylene and in particular ethane) are not directly available. This is probably because the amount of the corresponding compounds with two carbon atoms formed is too small for large-scale subsequent processes. Such subsequent processes may include, for example, the production of polyethylene from ethylene, the production of vinyl acetate monomer by selective gas phase oxidation of ethylene to acetic acid, or the production of ethylene oxide or ethylene glycol from ethylene.

[0005] In principle, these "side streams" can be utilized in suitable petrochemical complexes, such as steam crackers. However, according to the prior art, steam crackers are advantageously built on a very large scale (typically with an ethylene production capacity of more than 1,000 kilotons per year). In a typical methanol-to-olefins plant, an ethane fraction is produced, which, although in principle very suitable as a feedstock for a steam cracker, is of a significantly smaller order of magnitude, only about 1 to 50 kilotons per year. In view of this, it makes sense to integrate existing infrastructure or at very large production sites.

[0006] Furthermore, unless pipeline infrastructure is used, it is generally impractical to transport the desired hydrocarbons having two carbon atoms, in particular the low-value ethane. In contrast, the heavier by-products of the olefin production process (propane, a hydrocarbon having four carbon atoms) can be liquefied relatively easily and transported, for example, as LPG. For this purpose, there are already established logistics and infrastructure available.

[0007] That is, there are currently no suitable solutions for physically utilizing hydrocarbons with two carbon atoms outside of very large petrochemical complexes, or outside of petrochemical complexes with very specific conditions, in particular from these alternative olefin production processes.

[0008] Therefore, there is still a need to implement improved solutions in corresponding scenarios. Summary of the invention

[0009] In view of this, the invention proposes a method and a device for preparing one or more synthesis products, which have the corresponding features of the independent patent claims. Embodiments are the subject matter of the dependent patent claims and the following description.

[0010] The proposed method for preparing one or more synthesis products comprises: subjecting ethane as a first starting compound to oxidative dehydrogenation (i.e. ODH or ODHE) in a first starting stream to obtain a first product stream containing ethylene as a first product olefin, and subjecting a second starting compound containing oxygen and carbon to one or more catalytic conversion steps in a second starting stream to obtain a second product stream containing first and / or second product olefins. In this case, it is provided that at least a portion of the first product stream is subjected to one or more first purification and / or separation steps to obtain a first subsequent stream, at least a portion of the second product stream is not subjected to, is subjected to one or more second purification and / or separation steps (i.e. the one or more second purification and / or separation steps are optional) to obtain a second subsequent stream, and at least a portion of the first subsequent stream and at least a portion of the second subsequent stream are used to form a third starting stream, wherein the third starting stream is supplied to one or more third purification and / or separation steps.

[0011] In the proposed method, it is provided that the one or more first purification and / or separation steps include only partial removal of carbon dioxide or no removal of carbon dioxide. "Only partial" removal of carbon dioxide can here mean that less than 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the carbon dioxide contained is removed.

[0012] In the proposed process, a particularly higher carbon dioxide content in the first product stream, ie the product stream of the ODHE, compared to the second product stream of the olefin production process is particularly advantageously taken into account.The embodiments relate to advantageous embodiments of carbon dioxide removal.

[0013] The present invention and its embodiments will be described below using corresponding device components instead of method steps. In particular, this relates to "purification and separation steps", which are performed in corresponding "purification and decomposition parts", i.e. device parts of corresponding devices according to embodiments of the present invention. Corresponding explanations relate to method steps and device components in the same way.

[0014] The invention and its embodiments solve several problems of the known processes by combining the one or more catalytic conversion steps (which convert the second feedstock compound containing oxygen and carbon) with an ODHE, as explained in detail below, wherein surprisingly, significant advantages can be achieved in the design of the decomposition section. The invention and its embodiments enable advantageous utilization of light hydrocarbons, in particular ethane, from the one or more catalytic conversion steps by advantageous combination with an ODHE, wherein different carbon dioxide contents between the first and second product streams can be taken into account, and in some embodiments, different oxygen and acetylene contents can also be taken into account.

[0015] In the following, "one or more catalytic conversion steps" are simplified to "olefin production process" or "alternative olefin production process", these terms are synonymous. The (alternative) olefin production process differs from the steam cracking process in the catalytic conversion and the oxygen- and carbon-containing raw material compounds. In the combination proposed according to an embodiment of the present invention, the steam cracking process is not used or at most the steam cracking process is used in addition to the corresponding olefin production process. ODH or ODHE itself also represents an (alternative) olefin production process. However, when specifically discussing olefin production processes, this article always refers to a different type of olefin production process that is carried out in addition to ODH or ODH, which is not based on oxidative dehydrogenation reactions such as ODH or ODHE, but includes catalytic conversion of oxygen- and carbon-containing raw material compounds. In particular, this refers to the method for producing olefins or propylene from methanol mentioned at the beginning, and also refers to the hydrogenation reaction of carbon dioxide and the preparation and conversion of Fischer-Tropsch synthesis products.

[0016] In embodiments of the invention, a specific (higher) oxygen and / or acetylene content in the first product stream (i.e. the product stream of the ODHE) compared to the second product stream of the olefin production process can also be taken into account particularly advantageously. The invention and embodiments of the invention here firstly relate to an advantageous embodiment for the removal of carbon dioxide and in other advantageous embodiments this advantageous embodiment is supplemented as required with further elements, in particular for the removal of oxygen and / or acetylene.

[0017] In the present embodiment, the aspect of oxygen and acetylene content in the product stream (in this case, the "first product stream") of the ODHE is particularly relevant. The first product stream of the ODHE here usually contains more than 250 vol.-ppm (volume fraction per million), more than 500 vol.-ppm, more than 1,000 vol.-ppm, more than 2,500 vol.-ppm, more than 5,000 vol.-ppm, and sometimes even more than 10,000 vol.-ppm of oxygen (here based on the wet stream including water and acetic acid). This is because the ODHE catalyst (especially MoVNbTeO x The first product stream (type) is operated only with a certain residual oxygen content, which is present in particular at the reactor outlet. After condensation of water and acetic acid, these values ​​in subsequent streams of the first product stream obtained here increase to more than 500 vol.-ppm, more than 1,000 vol.-ppm, more than 2,000 vol.-ppm, more than 5,000 vol.-ppm, more than 10,000 vol.-ppm, and sometimes even more than 20,000 vol.-ppm of oxygen, respectively.

[0018] The acetylene content of the (first) product stream of the ODHE at the reactor outlet of the ODHE reactor (i.e. in the wet process gas including acetic acid) is typically from 50 vol.-ppm to 2000 vol.-ppm, in particular from 100 vol.-ppm to 1,000 vol.-ppm, in particular from 150 vol.-ppm to 750 vol.-ppm, which corresponds to about 100 vol.-ppm to 4,000 vol.-ppm, in particular from 200 vol.-ppm to 2,000 vol.-ppm, in particular from 300 vol.-ppm to 1,500 vol.-ppm in the subsequent stream after corresponding condensation of water and acetic acid.

[0019] The carbon monoxide content and the carbon dioxide content of the (first) product stream of the ODHE at the reactor outlet (i.e. in the wet process gas comprising acetic acid) are each independently of one another typically in the range from 0.25 vol.-% (volume percentage) to 5.0 vol.-%, in particular from 0.5 vol.-% to 4.0 vol.-%, in particular from 0.75 vol.-% to 2.5 vol.-%, which corresponds to about 0.5 vol.-% to 10.0 vol.-%, in particular from 1.0 vol.-% to 8.0 vol.-%, in particular from 1.5 vol.-% to 5.0 vol.-% in the subsequent stream after corresponding condensation of water and acetic acid.

[0020] In an embodiment of the proposed method, the one or more third purification and / or separation steps include carbon dioxide removal. As previously mentioned, according to the proposed method, the formation of the first subsequent stream is carried out with only partial removal of carbon dioxide or without removal of carbon dioxide, because the one or more first purification and / or separation steps include only partial removal of carbon dioxide or without removal of carbon dioxide. If the one or more third purification and / or separation steps include carbon dioxide removal, it can also be provided, where appropriate, that the formation of the second subsequent stream is carried out with only partial removal of carbon dioxide or without removal of carbon dioxide. In this case, it is provided that the one or more second purification and / or separation steps include only partial removal of carbon dioxide or without removal of carbon dioxide.

[0021] The carbon dioxide removal can be carried out when it is configured to be only partially removed, i.e. as a crude removal in the first, second and / or third separation sequence, for example using an amine wash, after which the carbon dioxide is further or completely removed in the form of a fine purification as part of the corresponding purification and / or separation step. However, in some embodiments it can also be configured that the carbon dioxide is partially removed using an alkaline wash. In all embodiments, the removal of carbon dioxide, whether complete or partial, particularly includes the use of an absorption liquid.

[0022] In one embodiment of the proposed method, also referred to herein as embodiment A, the one or more third purification and / or separation steps include carbon dioxide removal, whereas the formation of the first subsequent stream and the second subsequent stream is performed without performing carbon dioxide removal. That is, in this embodiment, neither the first purification and / or separation step nor the second purification and / or separation step includes carbon dioxide removal.

[0023] In this embodiment, referred to as A, the alkali wash is here in particular only carried out during the one or more third purification and / or separation steps, or in other words only in the third purification and decomposition section in which the one or more third separation steps are carried out. (As mentioned above, when referring to the first, second or third "purification and decomposition section", it is also referred to the one or more first, second or third purification and / or separation steps carried out using these sections).

[0024] Embodiment A is particularly suitable for the case where the capacity of the ODHE is significantly lower than the capacity of the olefin production process. This is especially true when the ODHE uses ethane from the olefin production process as a raw material completely or mainly, i.e., no or only a small amount of ethane from other sources is supplied.

[0025] In the case of olefin production processes with capacities of several hundred kilotons of olefins per year, the ethane stream for the ODHE is here typically less than 50 kilotons per year, 30 kilotons per year, 20 kilotons per year, 10 kilotons per year, 5 kilotons per year, and in particular less than 2 kilotons per year. Therefore, embodiment A is particularly suitable and advantageous if the ratio of the first subsequent stream (from the ODHE) to the second subsequent stream (from the olefin production process) is less than 1:3, less than 1:5, less than 1:10, less than 1:20 or less than 1:50.

[0026] Since the amount of the first product stream or its subsequent stream from the ODHE is significantly smaller than the amount of the second product stream or its subsequent stream from the olefin production process, the dilution obtained is sufficient when the product streams or subsequent streams are combined, so that the amount of oxygen from the ODHE has no influence on the third purification and decomposition section and on the purified product fraction obtained there. The acetylene is also diluted to such an extent that a concentration is achieved in the inlet stream of the third purification and decomposition section, which can be easily achieved within the framework of an acetylene removal step belonging to the olefin production process (e.g. selective hydrogenation). This is particularly advantageous within the framework of a conversion in which the ODHE is converted to utilize the ethane fraction from the olefin production process.

[0027] Therefore, only the task of removing the carbon dioxide in an advantageous manner remains. In the case presented here, this can be achieved by an alkaline wash in the third purification and decomposition section. In other words, the carbon dioxide removal comprised by the one or more third purification and / or separation steps can be performed in particular in the form of an alkaline wash. That is, a relatively complex regenerative carbon dioxide removal is not required.

[0028] This means that the dilution effect already mentioned above is utilized again. Surprisingly, it is thus possible to dispense with the raw gas treatment and the separate carbon dioxide removal in the first purification and decomposition section, in particular in the form of an amine wash, which is usually mandatory in the ODHE process. The use of a common alkali wash is only provided as an advantageous element in the third (common) purification and decomposition section.

[0029] It can therefore be provided in a corresponding embodiment that, taking advantage of the above-mentioned advantages, the formation of the first partial stream or the subsequent stream is carried out without feed gas treatment and / or carbon dioxide removal.

[0030] The term "raw gas treatment" refers to the treatment of the (first) product stream from the oxidative dehydrogenation reaction, or a stream derived therefrom, i.e. a subsequent stream. The raw gas treatment according to an embodiment of the invention is characterized in that acetylene and oxygen are removed simultaneously or partially from the product stream or its subsequent stream, wherein the reduction can be carried out to the same extent or to a different extent, for example by 100%, 90%, 80%, 70%, 60% or 50%, relative to the proportions originally contained in each. By further reaction of oxygen with carbon monoxide, the carbon monoxide content can also be partially reduced here, wherein additional carbon dioxide is formed. In the raw gas treatment, preferably one or more catalysts containing copper oxide or one or more catalysts containing at least one element of copper, manganese, zinc, nickel, platinum, palladium, rhodium and / or ruthenium, in particular mixed oxide catalysts, are used.

[0031] The features and advantages of such raw gas treatment are described in the patent literature, for example WO 2020 / 187572 A1, EP 3 708 557 A1, EP 3 708 558 A1 and WO 2018 / 153831 A1, to which reference is expressly made here.

[0032] The carbon dioxide formed in the ODHE or in the downstream raw gas treatment is, according to the prior art, usually removed by an amine wash assigned to the ODHE and, if appropriate, by a subsequent caustic wash as fine purification, and the product stream or the corresponding subsequent stream is then further purified and separated in a decomposition section, which itself can in particular comprise known cryogenic process steps (e.g. demethanizer, deethanizer, separation column).

[0033] In contrast, in the embodiment of the invention referred to as B, a feed gas treatment is carried out, to which the first product stream is subjected to form a first subsequent stream. In this case, the formation of the first partial stream or subsequent stream thus includes the feed gas treatment. This embodiment is particularly suitable for cases in which the acetylene removal in the common, i.e. in the third purification and decomposition section, which is carried out in the manner described for embodiment A, is no longer sufficient and / or the oxygen content reaches values ​​that are too high for processing.

[0034] As already mentioned above, the process gas from the ODHE usually contains a certain proportion of oxygen and acetylene at the reactor outlet. If the amount of the first product stream or its subsequent stream from the ODHE is increased compared to the second product stream or its subsequent stream from the olefin production process (e.g. additional ethane is supplied to the ODHE from another source) and / or the dilution effect is not sufficient to maintain the desired or technically necessary acetylene and / or oxygen content at any point in the common, i.e. third purification and decomposition section or to achieve the necessary product specifications of the target product obtained in the common, i.e. third purification and decomposition section, then in addition to embodiment A, a feed gas treatment is additionally used for the first product stream or its subsequent stream at an appropriate point.

[0035] Compared to a separate, non-integrated ODHE unit, it is not necessary to completely remove oxygen and / or acetylene when forming the subsequent stream of the first product stream. In addition, the dilution effect described for embodiment A can be advantageously utilized. This minimizes the workload for the raw gas treatment (in terms of equipment and construction costs) and also minimizes possible ethylene losses in the raw gas treatment. This fact is particularly helpful: the raw gas treatment does not need to be carried out "strictly", i.e. it can be carried out in a mild range at any time. This also extends the service life of the raw gas treatment.

[0036] According to one embodiment of the present invention, the residual oxygen content of the first product stream after raw gas treatment and the residual oxygen content in the corresponding subsequent stream of the first product stream are less than 100 vol.-ppm, 50 vol.-ppm, 25 vol.-ppm, 10 vol.-ppm, 5 vol.-ppm, 2 vol.-ppm, 1 vol.-ppm, 0.5 vol.-ppm or 0.1 vol.-ppm.

[0037] According to one embodiment of the present invention, the residual acetylene content of the first product stream after the raw gas treatment and the residual acetylene content in the corresponding subsequent stream of the first product stream are less than 100 vol.-ppm, 50 vol.-ppm, 25 vol.-ppm, 10 vol.-ppm, 5 vol.-ppm, 2 vol.-ppm, 1 vol.-ppm, 0.5 vol.-ppm, 0.3 vol.-ppm or 0.1 vol.-ppm.

[0038] In embodiments A and B, the first purification and decomposition section may include at least one compression as required, so that the subsequent flows of the first and second product flows can be combined, in particular at the same pressure level. That is, the formation of the first partial flow or the subsequent flow may include a pressure increase.

[0039] However, if the second product stream from the olefin production process or a subsequent stream thereof is at a similarly low level as the first product stream from the ODHE, such compression of the first purification and decomposition section may also be omitted and compression performed in the third purification and decomposition section. However, the olefin production process is usually carried out at a higher pressure level than the ODHE, so the first purification and decomposition section preferably includes compression.

[0040] Furthermore, the carbon dioxide removal is preferably carried out in principle at the highest possible pressure level.

[0041] In the embodiment referred to as C, the carbon dioxide removal is also carried out separately for the first product stream or its subsequent stream. That is, the formation of the first partial stream or the subsequent stream can include a (preliminary) removal of carbon dioxide. This preremoval is carried out in particular as a "bulk removal", i.e. as a rough removal of the main proportion.

[0042] If the caustic wash present in the third purification and decomposition section is not (any longer) sufficient to ensure the removal of the entire carbon dioxide load from the olefin production process, in particular from the ODHE, the purification and decomposition section assigned to the ODHE may include a carbon dioxide removal, the effect of which is a preliminary removal or "bulk removal" of carbon dioxide from the product stream of the ODHE. For this purpose, firstly the amine wash already mentioned above is applicable in principle, but the variant described later for embodiment F can also be used.

[0043] As described for embodiment B, implementation methods with or without consideration of feed gas treatment are feasible according to the corresponding specific needs. That is, the adjusted removal of carbon dioxide and the removal of oxygen and acetylene can be performed independently as needed, thereby further achieving the maximum possible efficiency improvement in the integration of ODHE and olefin production process.

[0044] In this embodiment C, in particular the carbon dioxide content which is first produced in the ODHE and which is higher than in the olefin production process, and the additional carbon dioxide proportion which is produced in the feed gas treatment as described for embodiment B, can be reduced or largely removed. In particular in olefin production processes, in which no or only small amounts of carbon dioxide are contained in the second product mixture or in subsequent mixtures thereof, the caustic wash in the common purification and decomposition section serves for fine purification and can be designed to be correspondingly small in size. In the case of a retrofit, in particular when supplementing an ODHE to an existing olefin production process, it is advantageous if the existing caustic wash can be sufficient.

[0045] According to this embodiment of the invention, the residual carbon dioxide content after removal of carbon dioxide in the purification and decomposition section assigned to the ODHE, i.e. the first purification and decomposition section and / or in its corresponding subsequent stream is less than 1.0 vol.-%, 0.5 vol.-%, 0.25 vol.-% or 0.1 vol.-%.

[0046] In the embodiment referred to as D, amine wash is carried out in the common purification and decomposition part. That is, the carbon dioxide removal included in the one or more third purification and / or separation steps can include amine wash. If the second product stream from the olefin production process or its subsequent stream is also a stream rich in carbon dioxide, then this variant is particularly suitable, which is particularly expected when converting a feed stream containing carbon dioxide in the olefin production process. In this embodiment, the carbon dioxide removal in the common purification and decomposition part particularly includes amine wash, and in the purification and decomposition part assigned to the ODHE, i.e. the first purification and decomposition part, an independent amine wash is particularly not provided.

[0047] The duplication of these carbon dioxide removal steps can thus be avoided. Within the framework of the carbon dioxide removal carried out here, both the amine wash and the alkaline wash for fine purification need only be carried out in a common purification and decomposition section.

[0048] The embodiment referred to herein as E, which integrates process water from the olefin production process with the removal of carbon dioxide in the purification and decomposition section of the ODHE, presents particular advantages. That is, in such embodiments, process water produced in the one or more catalytic conversion steps can be used in forming the second partial stream or subsequent stream.

[0049] In this embodiment, additional advantages are achieved by utilizing the water formed in the olefin production process. After the water and acetic acid are condensed and separated from the first product stream in a condensate separation step, the gas stream may still contain traces of acetic acid. In order to remove these acetic acids, another absorber (scrubber) can be used in the purification and decomposition section (i.e., the first purification and decomposition section) assigned to the ODHE, which is fed with aqueous condensate from the olefin production process. Since the reaction gas of the ODHE contains only traces of acetic acid when entering the scrubber, a neutral or only slightly acidic pH value is established in the scrubber, and in principle a certain proportion of carbon dioxide can also be removed from the reaction gas. That is, the outlet flow of the scrubber does not contain acetic acid or substantially does not contain acetic acid, and its carbon dioxide content is reduced. However, the carbon dioxide removal effect here is relatively small, that is, the main advantage is the removal of acetic acid, which is advantageous in terms of the material selection of the subsequent device parts.

[0050] In the embodiment designated F, particular advantages are achieved by utilizing the spent caustic liquor resulting from the caustic wash in the third purification and decomposition section. That is, spent caustic liquor from the carbon dioxide removal included in the one or more third purification and / or separation steps can be used in forming the first partial stream or subsequent streams.

[0051] In order to significantly reduce the carbon dioxide concentration in the purification and decomposition part (i.e. the first purification and decomposition part) of the ODHE, it is particularly advantageous to use the spent caustic liquor resulting from the caustic washing in the common purification and decomposition part (i.e. the third purification and decomposition part) in a further adsorber in whole or in part. Since the first product stream and its subsequent streams of the ODHE have a relatively high carbon dioxide concentration, which is usually and especially in this embodiment higher than the carbon dioxide concentration in the second product stream and its subsequent streams, and therefore also higher than the carbon dioxide concentration of the inlet stream formed by these two subsequent streams into the common purification and decomposition part (i.e. the third purification and decomposition part), the spent caustic liquor still has a certain residual capacity for reducing carbon dioxide in the product stream of the ODHE.

[0052] In particular, in this way, in the first purification and decomposition section, the carbon dioxide concentration can be reduced to at most 0.9 times, at most 0.8 times, at most 0.7 times, at most 0.6 times, at most 0.5 times and at most 0.3 times.

[0053] Embodiment F is also a subject of embodiments of the present invention in combination with the above-mentioned embodiments B, D and E. In particular, embodiment F represents a particularly advantageous refinement of embodiment C. Advantages are achieved here, in particular with regard to the utilization of operating resources.

[0054] The proposed apparatus for preparing one or more synthesis products is adapted to subject ethane as a first starting compound to oxidative dehydrogenation in a first starting stream to obtain a first product stream containing ethylene as a first product olefin, and to subject a second starting compound containing oxygen and carbon to one or more catalytic conversion steps in a second starting stream to obtain a second product stream containing first and / or second product olefins.

[0055] The proposed device has such means, which are adapted to subject at least a portion of the first product stream to one or more first purification and / or separation steps to obtain a first subsequent stream, subject at least a portion of the second product stream to one or more second purification and / or separation steps to obtain a second subsequent stream, use at least a portion of the first subsequent stream and at least a portion of the second subsequent stream to form a third raw material stream and supply the third raw material stream to one or more third purification and / or separation steps.

[0056] The proposed device is adapted to carry out the first purification and / or separation step with only partial removal of carbon dioxide or without removal of carbon dioxide.

[0057] With regard to further features and advantages of the corresponding apparatus and its embodiments, please explicitly refer to the above description of the method and its embodiments proposed by the present invention, as these descriptions also apply here.

[0058] The same applies to an apparatus which, according to one embodiment of the invention, is adapted to carry out a method according to any one embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Embodiments of the present invention will be described hereinafter purely by way of example with reference to the accompanying drawings, in which:

[0060] Figure 1 A method according to an embodiment is shown, and

[0061] Figure 2 Various aspects of a method according to an embodiment are shown. DETAILED DESCRIPTION

[0062] The embodiments described below are intended only to help the reader understand the claimed and previously described features. They are representative examples only and should not be considered as a final and / or limiting description of the features of the invention. It should be understood that the advantages, embodiments, examples, functions, features, structures and / or other aspects described above and below should not be considered as limitations on the scope of the invention, which is as defined in the claims, nor should they be considered as limitations on the equivalents of the claims, and other embodiments and modifications may be used without departing from the scope of the invention claimed.

[0063] Different embodiments of the present invention may include or have elements, components, features, parts, steps, devices, etc., or consist of them, or consist essentially of them, even if these combinations are not specifically described herein. In addition, the disclosure may include other inventions that are not currently claimed but may be claimed in the future, especially those inventions covered by the scope of the independent claims.

[0064] The descriptions related to the apparatus, device, arrangement, system, etc. according to the embodiments of the present invention may also be applicable to the process, procedure, method, etc. according to the embodiments of the present invention, and vice versa. The same, having the same function, corresponding in function, structurally the same or similar elements, method steps, etc. may be represented by the same reference numerals.

[0065] As mentioned several times, the present invention and its embodiments are primarily based on ODH, in particular ODHE. In embodiments of the present invention, this is combined with one or more of the olefin production processes mentioned at the outset, i.e. in particular with one or more

[0066] 1. MTO or MTP process based on methanol and / or dimethyl ether,

[0067] 2. Fischer-Tropsch synthesis of olefins, i.e. FTTO, and / or

[0068] 3. Combined with direct conversion of carbon dioxide or synthesis gas containing carbon dioxide.

[0069] As mentioned above, these olefin production processes have in common the inclusion of one or more catalytic conversion steps to which a feedstock compound containing oxygen and carbon is supplied.

[0070] If the feed compound supplied to the ODH or ODHE, in particular ethane, is referred to as the "first feed compound", then the oxygen- and carbon-containing feed compound supplied to the one or more catalytic conversion steps is also referred to herein as the "second" feed compound. The second feed compound may be carbon monoxide, carbon dioxide or an oxygen-containing compound, such as methanol or dimethyl ether.

[0071] In the following, other aspects of the corresponding method will be firstly described to explain the background of the present invention and its embodiments, and then specific embodiments will be mentioned.

[0072] As mentioned at the outset, ODHs or ODHEs are known per se, wherein ODHEs will be explained in particular below, but corresponding explanations also apply mutatis mutandis to ODHs of hydrocarbons other than ethane.

[0073] As mentioned above, firstly the MTO process and its variant, the MTP process, are well known and technically established in the olefin production process. In these processes, methanol is converted into a mixture of hydrocarbons of different chain lengths, in particular alkanes and olefins, under the action of a suitable catalyst (usually a molecular sieve or a zeolite). Other known variants also use dimethyl ether instead of methanol as an intermediate, or use a mixture of dimethyl ether and methanol.

[0074] Another reaction product produced in the MTO and MTP processes is water. In the MTO and MTP processes, only a very small proportion of acetylene is usually produced, so the corresponding methods only include acetylene removal designed for such a small amount of acetylene. Carbon dioxide is produced only in very small amounts at most, usually less than 0.5 vol.-%, less than 0.25 vol.-%, and in particular less than 0.1 vol.-%, which can be removed relatively easily by alkali washing. For example, reference can be made to professional literature, such as MR Gogate's article "Methanol-to-olefins process technology: current status and future prospects", Petroleum Science and Technology 2019, 37 (5), 559-565, which contains an up-to-date overview of the corresponding MTO and MTP technical methods, including typical process flow charts. The basic process steps of the decomposition part of the MTO or MTP device can include water separation, alkali washing, drying, compression, demethanization, deethanization, depropanization, and separation of hydrocarbons with two carbon atoms and separation of hydrocarbons with three carbon atoms. Also known are methanol to gasoline (MTG) processes, but these generally result in a heavier product spectrum.

[0075] As is well known, the Fischer-Tropsch synthesis process is a heterogeneous catalytic process for converting synthesis gas into liquid hydrocarbons. The principle is, for example, reference to "Fischer-Tropsch Technology" by A. Steynberg and M. Dry (eds.), Elsevier, 2006, Bd. 152, or "Small-Scale Fischer-Tropsch gas-to-liquids facilities: advances and applications" by A. de Klerk, in "Fischer-Tropsch Synthesis, Catalysts, and Catalysis" by Davis, BH and Occelli, ML (eds.), CRC Press, 2016. These products can vary from short-chain hydrocarbons to long-chain hydrocarbons, including alkanes and olefins, depending on the process conditions. Iron or cobalt catalysts are mostly used between 150° C. and 300° C. The selectivity of the Fischer-Tropsch synthesis process can be set by operating conditions, catalyst type, carrier and reactor configuration. The latest methods also focus in particular on improving the selectivity for light olefins, see for example HM Torres Galvis et al., "Supported Iron Nanoparticles as Catalysts for Sustainable Production of Lower Olefins", Science, 335, 835-838, or HM Torres Galvis et al., "Catalysts for Production of Lower Olefins from Synthesis Gas: A Review", ACS Catal., 3, 2130-2149.

[0076] Similar to the above-mentioned MTO or MTP processes, the broad product distribution including olefins and alkanes requires appropriate fractionation, which can include the process steps of the decomposition part already mentioned in MTO and MTP. The acetylene and carbon dioxide contents here are roughly of the same order of magnitude as in the previously mentioned MTO and MTP processes.

[0077] The direct conversion of carbon dioxide or carbon dioxide-containing synthesis gas is becoming increasingly important, particularly in the context of efforts to reduce carbon dioxide emissions. Current research directions regarding this method are aimed at converting carbon dioxide and hydrogen (where appropriate in the presence of carbon monoxide) into hydrocarbons. Products with two to four carbon atoms (alkanes and olefins), in particular propylene, are of particular interest here. Mixtures of carbon dioxide and carbon monoxide can also be used here, i.e., mixtures of carbon dioxide and hydrogen or synthesis gas enriched in carbon dioxide are fed to the corresponding reaction steps.

[0078] The technical literature also describes, for example, the combination of reforming and the Fischer-Tropsch process or FTTO process for the preparation of olefins. In addition, processes for combining synthesis gas to methanol and the MTO or MTP process in one step can also be found in the technical literature. These processes are usually based on the combination of zirconium-zinc oxide (for methanol synthesis) with H-SAPO-34 as MTO or MTP catalyst.

[0079] There have also been studies on the hydrogenation of carbon dioxide over bifunctional catalysts (e.g., W. Li et al., "A short review of recent advances in CO2 hydrogenation to hydrocarbons over heterogeneous catalysts", RSC Adv., 2018, 8, 7651, K. Cheng et al., "Direct and Highly Selective Conversion of Synthesis Gas into Lower Olefins: Design of a Bifunctional Catalyst Combining Methanol Synthesis and Carbon–Carbon Coupling", Angew. Chem. Int. Ed. 2016, 55, 4725-4728 and F. Jiao et al., "Selective conversion of syngas to light olefins", Science, 2016, 351, 1065-1068, and U. Olsbye, "Single-Pass Catalytic Conversion of Syngas into Olefins via Methanol", Angew. Chem. Int. Ed. 2016, 55, 7294-7295).

[0080] However, such systems are also suitable in principle for converting carbon monoxide or any desired mixture of carbon monoxide and carbon dioxide into hydrocarbons, in particular olefins such as ethylene and / or propylene.

[0081] The bifunctional catalyst catalyzes two reaction steps here, namely the conversion of the components of the synthesis gas into one or more oxygenates such as methanol and / or dimethyl ether as intermediates and the further conversion of one or more intermediates into the desired target compound in the form of said one or more hydrocarbons. A bifunctional catalyst used here generally combines the methanol catalyst used with an acidic zeolite structure, which catalyzes the subsequent reaction.

[0082] Alternatively, the parallel process of the two reaction steps can also be carried out by combining two or more suitable catalysts as a physical mixture in a catalyst bed, which catalysts each preferably catalyze the corresponding reaction step. The corresponding catalysts can be the essentially known catalysts mentioned above for methanol or dimethyl ether synthesis or for further reactions.

[0083] Based on the mechanistic similarity of the second reaction step to the aforementioned MTO and MTP processes, comparable acetylene contents in the corresponding product streams can be expected, however, due to process limitations, the carbon dioxide content in the product stream of such carbon dioxide-based processes is generally significantly higher, in particular above 1 vol.-%, above 5 vol.-%, above 10 vol.-%, and if the reaction is only partially converted in each pass, it can also be above 25 vol.-%.

[0084] That is, all the olefin production processes mentioned do not produce only one desired target product, but always produce a mixture of multiple products, i.e. hydrocarbons with different chain lengths and different ratios of alkanes and alkenes. That is, they always contain significant proportions of other components that are different from the only desired target product.

[0085] This requires appropriate fractionation, as described. Here, the fraction with a certain number of carbon atoms always has a mixture of corresponding olefins and alkanes, in the case of two carbon atoms, ethane and ethylene. Although it is almost known that alkanes are selectively generated (especially in the Fischer-Tropsch synthesis and the conversion of carbon dioxide or carbon dioxide-containing synthesis gas), these embodiments are not very relevant within the framework of the present invention and are therefore not considered further below.

[0086] That is, within the framework of the olefin production process, it is always possible to maximize only a certain fraction with a certain number of carbon atoms and optimize, for example, the selectivity to olefins, instead of producing only or almost only one product or only olefin products. This applies in particular to the relevant target product ethylene within the framework of an embodiment of the present invention, and thus also to the ethane that is necessarily produced in the fraction of compounds with two carbon atoms in the olefin production process according to the invention.

[0087] In the product stream of the olefin production process of the type described here, acetylene is usually not present or only present in small amounts. "Presence in small amounts" is particularly understood to mean that the acetylene content is lower than the acetylene content in the above-mentioned ODHE product stream. In particular, in MTO or MTP and FTTO processes, the carbon dioxide content in the second product stream is lower than the carbon dioxide content in the first product stream or its subsequent stream. The typical ratio of the carbon dioxide content in the corresponding first product stream to the carbon dioxide content in the corresponding second product stream or the corresponding subsequent stream (as defined below) is 4:1 or more, 8:1 or more, 12:1 or more, 20:1 or more and 30:1 or more.

[0088] The basic method of integrating ODHE and MTO can be found in patent applications CN 113845401 A, CN 113869985 A and CN113896608A. The common point of these documents is that the ethane fraction from the MTO process is used as the raw material of ODHE. Next, the product stream of ODHE is sent to the decomposition part of the MTO process after the absorption removal of carbon dioxide, and is combined with the raw material product from the MTO reaction there. The steps of removing oxygen in the product stream of ODHE are also disclosed in these documents, however, this oxygen removal is only carried out by the reaction of oxygen with carbon monoxide, and is usually arranged upstream of compression (see CN113896608 A). These documents also include the introduction of auxiliary gas (especially carbon monoxide) for this oxygen removal. There is no description of the appropriate removal of acetylene from the product stream of ODHE in the document, and the fact that the product stream of ODHE contains a significant proportion of acetylene compared to the olefin production process is not mentioned anywhere. As mentioned above, the decomposition section of the olefin production process does not however contain suitable means to remove such high concentrations of acetylene that are typically present in the product stream of the ODHE. Therefore, these documents do not disclose a suitable solution for removing acetylene when using a common decomposition section in the case of an integrated olefin production process and an ODHE.

[0089] Another application, CN 113831207 A, involves the use of pressure swing adsorption (PSA) in the product gas stream of the ODHE in order first to separate off diluents and other (light) components, such as oxygen and carbon monoxide, after which the fraction thus formed, rich in hydrocarbons having two carbon atoms, is fed to the decomposition part of the MTO process. This is also not a suitable solution for removing acetylene.

[0090] For the prior art of common process steps, such as distillation (cryogenic and non-cryogenic), carbon dioxide removal, etc., reference is made to the specialist literature or to the knowledge known to the skilled person.

[0091] As already explained, the second product stream from the olefin production process is usually oxygen-free and contains only a low proportion of acetylene compared to the ODHE, and therefore the corresponding decomposition part of the olefin production process does not contain any suitable means for removing oxygen, nor means for removing higher concentrations of acetylene.

[0092] However, this removal is absolutely necessary in terms of product specifications (especially ethylene product) and for process and safety reasons, otherwise severe oxygen accumulation (explosion risk) or fouling effects may occur. That is, according to the prior art, it is generally impossible to feed the first product stream from the ODHE directly into the decomposition part of the olefin production process. The above documents only solve the problem of oxygen, and for technical implementation, a solution is urgently needed to deal with the relatively high acetylene content in the ODHE product stream.

[0093] In particular, taking into account the different carbon dioxide contents in the first product stream from the ODHE and the second product stream from the olefin production process, an advantageous solution is nevertheless required to achieve an efficient overall process. The present invention and its embodiments provide a corresponding solution.

[0094] As already mentioned above, the present invention and its embodiments solve the above mentioned problems by combining an olefin production process with an ODHE, wherein surprisingly, significant advantages can be achieved in the design of the decomposition section.

[0095] In particular, it is necessary to take into account a specific (higher) carbon dioxide, oxygen and / or acetylene content in the first product stream compared to the second product stream ODHE of the olefin production process. Embodiments of the invention relate here firstly to an advantageous embodiment for carbon dioxide removal and, if necessary, to supplement this advantageous embodiment with further elements for oxygen and / or acetylene removal.

[0096] The term "purification and decomposition section" is used above and below. This section may be particularly adapted or used to perform one or more method steps, which are selected in appropriate combination from the following steps:

[0097] ·compression

[0098] Condensation

[0099] Sedimentation / phase separation, especially gas-liquid separation

[0100] ·dry

[0101] · Separation by distillation or rectification (cryogenic and non-cryogenic), in particular separation of hydrocarbons with 2 or more carbon atoms from lighter compounds (demethanization), separation of hydrocarbons with 3 or more carbon atoms from lighter compounds (deethanization), separation of hydrocarbons with 4 or more carbon atoms from lighter compounds (depropanization), separation of hydrocarbons with 2 carbon atoms from each other, separation of hydrocarbons with 3 carbon atoms from each other, etc.

[0102] Absorptive removal components, in particular by regenerable and non-regenerable washes (e.g., removal of carbon dioxide by amine washes or alkaline washes)

[0103] Feed gas treatment for ODHE process gases as defined above

[0104] Adsorption removal of components, especially oxygen-containing compounds

[0105] Pressure Swing Adsorption (PSA)

[0106] Membrane separation

[0107] Reactive removal of components, in particular by catalytic conversion, such as hydrogenation and / or oxidation

[0108] Other relevant process steps may include acetic acid processing, for example, processing acetic acid produced in an ODHE and obtaining it as another valuable product in a desired quality.

[0109] In principle, these product streams or streams formed therefrom, ie parts of subsequent streams or subsequent streams from ODHE and olefin production processes, can be supplied to one or more purification and decomposition sections. These purification and decomposition sections can each independently of one another comprise one or more of the above-mentioned process steps.

[0110] The first or second purification and decomposition section can firstly process the first product stream of the ODHE or the second product stream of the olefin production process, wherein each forms a corresponding subsequent stream. The corresponding partial stream can be formed as a partial product stream or a partial subsequent stream and is only partially transferred to a subsequent process step. In the following, the terms "product stream" and "subsequent stream" should also include such partial streams in the sense that a partial product stream or a partial subsequent stream represents a part of the corresponding product stream or subsequent stream.

[0111] The process according to an embodiment of the invention comprises at least one (third) purification and decomposition section. The third purification and decomposition section is fed into a stream which is produced by combining subsequent streams or corresponding parts of subsequent streams of the first and second product streams.

[0112] In view of the above problems, the object of the present invention is to demonstrate the advantageous utilization of light hydrocarbons, in particular ethane, obtained from the above process, taking into account different carbon dioxide, oxygen and acetylene contents, by an advantageous combination of an olefin production process with an ODHE, as mentioned above in other words.

[0113] Furthermore, by integrating corresponding plant parts, in particular with regard to product separation and purification, additional technical and economic advantages can be achieved.Corresponding embodiments of the invention are referred to as A to F in the foregoing.

[0114] exist Figure 1 A method according to an embodiment of the present invention is shown, generally designated 100 .

[0115] In the method 100, the required reactants ethane C2H6 and oxygen O2 are supplied to the catalytic oxidative dehydrogenation 110, wherein ethane is also referred to herein as the "first feed compound". In order to provide a corresponding material flow, a reflux as will be explained below can also be used. In addition, water vapor H2O can be fed to the catalytic oxidative dehydrogenation 110 as a diluent as required. The required water can at least partially come from the refined water phase of the optional acetic acid purification 140 as will be explained below or from the corresponding aqueous fraction of the second purification and decomposition section 220, as indicated by the dashed arrow.

[0116] That is, ethane C2H6, also referred to herein as the "first raw material compound", is supplied to the oxidative dehydrogenation in a corresponding raw material stream, which is also referred to herein as the "first raw material stream" and is labeled 11. The "first raw material stream" can be selectively understood here as a material stream C2H6 containing (only) ethane, but can also be understood as a mixed stream consisting of at least a part of the material streams C2H6, O2 and H2O, etc. shown.

[0117] In the catalytic oxidative dehydrogenation 110, a first product stream 12 containing ethylene is formed, which is referred to herein as "first product olefins", wherein the first product stream is subjected to a condensate separation 120. In the condensate separation, a condensate fraction 15 containing mainly water and acetic acid is formed, as well as a corresponding fraction reduced in water and acetic acid, wherein the latter is also referred to herein as a "subsequent stream" of the first product stream 12 and is referenced as 13.

[0118] The condensate fraction 15 can be subjected to the above-described optional acetic acid treatment 140, in which a water fraction H2O containing essentially water and an acetic acid fraction AcOH containing essentially acetic acid are formed.

[0119] Downstream of the condensate separation 120, the subsequent stream 13 is in a form reduced in water and acetic acid. The subsequent stream can now be sent to the first purification and decomposition section 130 as required, which can optionally include compression, feed gas treatment and carbon dioxide removal, respectively, but not shown separately.

[0120] The component mixture obtained downstream of the first purification and decomposition section 130, also referred to herein as the "subsequent stream" of the first product stream 12, is referred to as the "first subsequent stream" and is labeled 14 for better distinction, and contains at least a portion of ethane, ethylene, and compounds with lower boiling points than ethylene from the first product mixture. It has reduced water and acetic acid compared to the first product stream. In embodiment B, the first subsequent stream has reduced oxygen and acetylene, or is substantially free of these components. If carbon dioxide removal 133 is used (as described above for embodiment C), the first subsequent stream can be reduced relative to the first product stream at least in terms of carbon dioxide.

[0121] In the method 100, the second feedstock compound containing oxygen and carbon is also subjected to one or more catalytic conversion steps 210 in the second feedstock stream 21 to obtain a second product stream 22 containing the first product olefin, i.e. ethylene, and / or the second product olefin, e.g. propylene. The one or more catalytic conversion steps can be described, for example, during the MTO, MTP or FTTO process, or in the carbon dioxide hydrogenation process as described above. Here, the "second feedstock stream" can be selectively understood as a material stream containing (only) the second feedstock compound, but can also be understood as a mixed stream consisting of a plurality of material streams.

[0122] The second product stream particularly comprises a mixture of alkanes and / or olefins, particularly containing ethane and / or ethylene. Water or water vapor is not normally supplied to the olefin production process 210, but can also be supplied when needed. The second product stream 22 can optionally pass through a second purification and decomposition section 220, wherein a "subsequent stream" of the second product stream 22 is produced, also referred to herein as a "second subsequent stream". If it is necessary to add water or water vapor H2O in the olefin production process 210, for example as a diluent, it can be carried out as described above for the catalytic oxidative dehydrogenation 110.

[0123] The subsequent streams 14 and 23 are then combined and supplied to a common third purification and decomposition section 310. This may in particular include the method steps already listed, but in particular include appropriate fractionation. In particular, the carbon dioxide removal 313, which is not shown separately, may in particular include alkali washing (in the embodiments A, B and C described), but may also optionally include regeneration washing (embodiment D). In particular, only the first purification and decomposition section 130 or the third purification and decomposition section 130 includes such regeneration washing and / or alkali washing to avoid duplication of method steps. However, the embodiment may also include: in the first purification and decomposition section 130, the carbon dioxide removal is performed in the form of washing, in which the waste alkali liquor from the carbon dioxide removal in the downstream third purification and decomposition section 310 may be used. In principle, in these and other embodiments, another additional optional alkali washing may also be included as fine purification.

[0124] In the third purification and decomposition section 310, simultaneously or successively and in a known order, a methane fraction C1 is formed, which may also contain compounds with a lower boiling point than methane, a fraction C2 containing hydrocarbons with two carbon atoms, a fraction C3 containing hydrocarbons with three carbon atoms and a fraction C4 containing hydrocarbons with four or more carbon atoms.

[0125] The fraction C2 containing hydrocarbons having two carbon atoms obtained in the third purification and decomposition section 310 can be subjected to a separation (split) 410 of these hydrocarbons from one another. The ethane C2H6 obtained here can be used in whole or in part as a reaction feedstock for the catalytic oxidative dehydrogenation 110, and ethylene C2H4 is obtained as a valuable product in accordance with the specifications (especially in terms of carbon dioxide, oxygen and acetylene content). That is, the ethane C2H6 for ODHE can be provided here in part or in whole from the reflux of the separation 410.

[0126] exist Figure 21 shows various aspects of a method according to an embodiment of the invention, wherein the method steps located upstream of the first and second purification and decomposition sections 130, 220 and downstream of the third purification and decomposition section 310 are not shown. Their connection relationship is derived from the material flows 13, 22, C1, C2, C3 and C4+ shown in the figure.

[0127] Figure 2 Here, the streams are shown which are directed to the first purification and decomposition section 130 and are advantageously utilized there in the embodiment E or F. On the one hand, in embodiment E, this is the condensate 24 from the catalytic olefin production process 210, which is separated from the second product stream 22 in the second purification and decomposition section 220, and on the other hand, in embodiment F, this is the spent caustic soda 31 from the caustic wash in the third purification and decomposition section 310.

Claims

1. A method (100) for preparing one or more synthetic products, in which method, - subjecting ethane as first starting compound to an oxidative dehydrogenation (110) in a first starting stream (11) to obtain a first product stream (12) containing ethylene as first product olefin, - subjecting a second feed compound containing oxygen and carbon to one or more catalytic conversion steps (210) in a second feed stream (21) to obtain a second product stream (22) containing first and / or second product olefins, It is characterized in that - subjecting at least a portion of said first product stream (12) to one or more first purification and / or separation steps (130) in order to obtain a first subsequent stream (13, 14), - subjecting at least a portion of the second product stream (21) to no, to, or to one or more second purification and / or separation steps (220) to obtain a second subsequent stream (22, 23), and - using at least a portion of the first subsequent flow (13, 14) and at least a portion of the second subsequent flow (22, 23) to form a third feed flow, wherein the third feed flow is supplied to one or more third purification and / or separation steps (310), - wherein the one or more first purification and / or separation steps (130) comprise only a partial removal of carbon dioxide or no removal of carbon dioxide.

2. A method (100) according to claim 1, in which the one or more third purification and / or separation steps (310) include carbon dioxide removal, wherein the formation of the first subsequent flow (13, 14) and the second subsequent flow (22, 23) is carried out without performing carbon dioxide removal.

3. The method (100) according to claim 2, wherein the carbon dioxide removal comprised in the one or more third purification and / or separation steps (310) is performed in the form of alkaline washing.

4. The method (100) according to claim 2 or 3, in which the formation of the first partial flow or subsequent flow (13, 14) is carried out without feed gas treatment.

5. The method (100) according to claim 2, wherein the forming of the first partial flow or subsequent flow (13, 14) comprises feed gas processing.

6. The method (100) according to any one of claims 2 to 5, in which the forming of the first partial flow or subsequent flow (13, 14) comprises a pressure increase.

7. The method (100) according to any one of claims 2 to 6, wherein the carbon dioxide removal comprised in the one or more third purification and / or separation steps (310) comprises an amine wash.

8. The method (100) according to any one of claims 2 to 7, wherein process water produced in the one or more catalytic conversion steps (210) is used in one or more of the first purification and / or separation steps (130).

9. The method (100) according to any one of claims 2 to 8, wherein the spent alkali liquor from the carbon dioxide removal included in the one or more third purification and / or separation steps (310) is used in one or more of the first purification and / or separation steps (130).

10. An apparatus for preparing one or more synthetic products, the apparatus being adapted to: - subjecting ethane as first starting compound to an oxidative dehydrogenation (110) in a first starting stream (11) to obtain a first product stream (12) containing ethylene as first product olefin, - subjecting a second feed compound containing oxygen and carbon to one or more catalytic conversion steps (210) in a second feed stream (21) to obtain a second product stream (22) containing first and / or second product olefins, Features Means, wherein the means is adapted to: - subjecting at least a portion of said first product stream (12) to one or more first purification and / or separation steps (130) in order to obtain a first subsequent stream (13, 14), - subjecting at least a portion of the second product stream (21) to no, to, or to one or more second purification and / or separation steps (220) in order to obtain a second subsequent stream (22, 23), - using at least a portion of the first subsequent flow (13, 14) and at least a portion of the second subsequent flow (22, 23) to form a third feed flow and supplying the third feed flow to one or more third purification and / or separation steps (310), and - performing the one or more first purification and / or separation steps (130) with only partial removal of carbon dioxide or without removal of carbon dioxide.

11. The apparatus according to claim 10, adapted to perform the method according to any one of claims 1 to 9.

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