Method and plant for producing one or more process products

Abstract

The invention relates to a method (100) for producing one or more process products, comprising providing a liquid hydrogenation feedstock (101) containing unsaturated hydrocarbons having three or more carbon atoms, hydrogenating (11) the hydrogenation feedstock (101) or a portion thereof to obtain a hydrogenation product (103), forming (12, 13) a reforming feedstock (105) using the hydrogenation product (103) or a portion thereof, and reforming (14) the reforming feedstock (105) to obtain a reforming product (107), wherein the reforming (14) comprises steam reforming and / or autothermal reforming. A corresponding plant is also proposed.

Description

[0001] Description

[0002] Process and plant for producing one or more process products

[0003] Area

[0004] The present disclosure relates to a process and a plant for the production of one or more process products.

[0005] background

[0006] Methods and devices for steam cracking of hydrocarbons are known and are described, for example, in the article "Ethylene" in Ullmann's Encyclopedia of Industrial Chemistry, online since April 15, 2007, DOI 10.1002 / 14356007. a10_045.pub2.

[0007] Steam cracking produces so-called cracking gases, which are hydrocarbon mixtures with hydrocarbons of varying chain lengths, saturation, and structure. To obtain the desired products from a cracking gas, it must be separated. Various separation sequences are known from the prior art and are described in detail, for example, in the aforementioned article. These can include, for instance, demethanization followed by deethanization, or deethanization followed by demethanization.

[0008] Typically, hydrocarbon mixtures containing mono- and polyunsaturated hydrocarbons with three or more carbon atoms can be obtained in corresponding separation processes. These cannot always be used directly, making conversion to other products desirable. The present disclosure expressly extends to the use of such hydrocarbons and hydrocarbon mixtures from sources other than steam cracking. The aim is to provide processes and equipment that enable the efficient use of the aforementioned hydrocarbons and overcome certain disadvantages of known processes, which will be explained in detail below.

[0009] Overview

[0010] Against this background, a process and a plant for producing one or more process products with the features of the independent patent claims are proposed. Embodiments are the subject of the dependent patent claims and the following description.

[0011] The proposed process for producing one or more process products comprises providing a liquid hydrogenation feed containing unsaturated hydrocarbons with three or more carbon atoms, hydrogenating the hydrogenation feed or part thereof in the liquid state to obtain a hydrogenation product, forming a reforming feed using the hydrogenation product or part thereof, and reforming the reforming feed to obtain a reforming product, wherein the reforming includes steam and / or autothermal reforming.

[0012] The proposed process enables the use of unsaturated hydrocarbons with three or more carbon atoms, for example, in corresponding fractions from steamer fields or ethylene plants, in steam and / or autothermal reforming. This avoids problems that can occur in combination with other processes, such as increased oxygen demand in partial oxidation. Likewise, as explained in detail below, heat and exothermicity problems, which are conventionally difficult to manage, are reduced.

[0013] The proposed combination of liquid hydrogenation of a fraction containing unsaturated hydrocarbons with three or more carbon atoms with a reforming of the hydrogenation product thus enables the use of longer-chain unsaturated hydrocarbons as feedstock for reformer-based plants without the need for complex measures for cooling and exothermic control as in conventional hydrogenation or desulfurization. Furthermore, the risks of soot formation or polymerization, which are to be expected when heating longer-chain unsaturated hydrocarbons, are avoided. For further explanation, please refer to the detailed description of the embodiments proposed here in conjunction with the figures.

[0014] In certain embodiments of the proposed process, the provision of the liquid hydrogenation feed comprises the steam cracking of a hydrocarbon mixture to obtain cracking gas and the formation of the hydrogenation feed using a portion of the cracking gas. The process thus enables the advantageous utilization of corresponding hydrocarbons produced during steam cracking.

[0015] In certain embodiments of the proposed process, the formation of the hydrogenation feed using a portion of the cracked gas includes a deethanization step. This can be performed upstream or downstream of a demethanization step. A heavy fraction from the deethanization can be used as the hydrogenation feed or processed into it.

[0016] In certain embodiments of the proposed process, it is provided that the process includes the provision of one or more components of the reforming product as the process product or one of several process products. These could be, for example, hydrogen or carbon monoxide, which can be used for suitable purposes.

[0017] In certain embodiments of the proposed process, it is envisaged that the process includes the conversion of one or more components of the reforming product into the process product or one of several process products. In this case, the proposed process can serve as a composite process for providing a wide variety of process products.

[0018] In certain embodiments of the proposed process, the aforementioned conversion includes the reaction of hydrogen with nitrogen to form ammonia and / or of carbon dioxide with hydrogen to form methanol. In certain embodiments of the proposed process, unsaturated hydrocarbons with three or more carbon atoms are present in the hydrogenation feedstock at a concentration of up to 100% by weight. The proposed process and its embodiments thus enable the material utilization of such component mixtures, which would otherwise typically be processed purely thermally.

[0019] In certain embodiments of the proposed process, it is provided that the hydrocarbons with three or more carbon atoms include hydrocarbons with up to 12 carbon atoms. Correspondingly heavy hydrocarbons can also be processed using this method.

[0020] In certain embodiments of the proposed process, the reforming of the reforming insert includes steam and / or autothermal reforming. Corresponding combinations can also be used, and the choice of the specific reforming process can depend in particular on product requirements or local conditions such as oxygen availability.

[0021] In certain embodiments of the proposed process, the reforming of the reforming insert includes a pre-reforming step. This allows the processing of longer-chain compounds without modifying the catalyst used for reforming and without the risk of carbonization or polymerization.

[0022] The proposed plant for the production of one or more process products comprises a hydrogenation reactor in which a liquid, unsaturated hydrocarbon containing three or more carbon atoms can be hydrogenated to obtain a hydrogenation product; a processing unit for forming a reforming feed using the hydrogenation product; and a reforming unit with a steam and / or an electric reformer for reforming the reforming feed to obtain a reforming product. Advantages and features described with respect to the proposed process and its embodiments also apply to the proposed plant and vice versa. These are therefore described only once, and reference may be made to the respective explanations.

[0023] The same applies to a facility that can be set up to carry out a procedure according to any configuration.

[0024] Drawings

[0025] Aspects proposed within the scope of this disclosure are explained in more detail with reference to the accompanying drawing. This drawing shows

[0026] Figure 1 shows a method not according to the invention;

[0027] Figure 2 shows a method according to a proposed embodiment; and

[0028] Figure 3 Process steps for providing a hydrogenation insert.

[0029] Designs

[0030] The embodiments described below are provided solely to assist the reader in understanding the claimed and previously explained features. They represent only representative examples and are not intended to be considered exhaustive or limiting with regard to the features of the invention. It is understood that the advantages, embodiments, functions, features, structures, and / or other aspects described above and below are not to be considered limitations of equivalents to the claims, and that other embodiments may be used and modifications made without deviating from the scope of the claimed invention.

[0031] Explanations relating to devices, apparatus, arrangements, systems, etc., according to embodiments of the present invention may also apply to methods, processes, procedures, etc., according to embodiments of the present invention, and vice versa. Identical, functionally equivalent, structurally identical, or comparably constructed elements, process steps, etc., may be indicated by identical reference numerals.

[0032] The terms used in this disclosure have the meanings generally accepted in the scientific community. For definitions of the terms used here, please refer to the specialist literature cited at the beginning.

[0033] Steam reforming is described, for example, in H.-W. Häring (ed.), “Industrial Gases Processing”, Wiley-VCH, 2006, in particular section 5.2.2.1, “Generation of Synthesis Gas by Steam Reforming”, and section 5.2.4, “Processes for the Production of Synthesis Gas from Hydrocarbons”. Autothermal reforming is described accordingly in section 5.2.2.3, “Generation of Synthesis Gas by Autothermal Reforming (ATR)”.

[0034] Steam or autothermal reforming can be operated with methane-rich feedstocks such as natural gas. Designs are also suitable for processing light, liquid hydrocarbons such as naphtha or liquefied petroleum gas (LPG). For steam reforming such feedstocks, a special catalyst with alkaline components, usually potash, can be used in the catalyst tubes to prevent soot formation on the catalyst. An alternative is the use of a pre-reformer, classically an adiabatic fixed-bed reactor, which produces a pre-reformed mixture of methane, carbon monoxide, and hydrogen at temperatures around 450 to 550 °C. Since the methane content is still exceptionally high at these temperatures, the resulting gas mixture is then subjected to the actual steam or autothermal reforming.

[0035] The term "synthesis gas" is intended to refer in particular to a gas mixture containing hydrogen and carbon monoxide, wherein the combined content of hydrogen and carbon monoxide is particularly greater than 50% by weight. Carbon dioxide may also be present, and the content of hydrogen, carbon monoxide, and carbon dioxide can be influenced by a known water-to-gas conversion process. A "synthesis raw gas" also contains, in particular, water and unreacted hydrocarbons from the feedstock. Figure 1 shows a process not according to the invention in the form of a schematic process flow diagram. The process according to Figure 1 is particularly suitable for processing common feedstocks such as natural gas, liquefied petroleum gas (LPG), or naphtha, which do not have a particularly high content of unsaturated hydrocarbons with three or more carbon atoms.

[0036] The process illustrated in Figure 1 comprises preheating 110, hydrogenation 120, desulfurization 130, and subsequent reforming 140 of a corresponding feedstock 111, wherein the hydrogenation can be carried out with the addition of hydrogen 102 and the reforming 140, in the form of steam or autothermal reforming with optional pre-reforming, can be carried out with the optional addition of oxygen 106. The result is a reforming product 107 in the form of synthesis raw gas.

[0037] If feedstocks with a high proportion of unsaturated hydrocarbons with three or more carbon atoms, such as those obtained in ethylene plants by steam cracking, are to be used in processes of the type shown in Figure 1, problems can arise. For example, polymerization and / or soot formation can occur during the heating to the necessary temperature at the inlet of the pre-reforming unit.

[0038] Operation without preheating in partial oxidation is possible, but is associated with the disadvantages of partial oxidation compared to processes with pre- and steam and / or autothermal reforming, particularly high oxygen consumption. Furthermore, in such applications, the heat release in the hydrogenation, which is typically carried out at high temperatures of 250 to 400 °C, is too high to achieve complete hydrogenation in a single pass. A cooled feed gas recycle system would be required.

[0039] The following designs, explained again with reference to the state of the art, eliminate these disadvantages.

[0040] This proposal combines liquid hydrogenation with reforming, specifically including pre-reforming as well as steam reforming and / or autothermal reforming. This enables the use of longer-chain, unsaturated hydrocarbons as feedstock for such plants without requiring complex cooling or exothermic control measures in conventional hydrogenation and desulfurization processes. Furthermore, the risk of soot formation or polymerization, which is to be expected when heating longer-chain unsaturated hydrocarbons, is avoided in appropriate configurations.

[0041] Figure 2 shows a process according to a proposed embodiment in the form of a schematic process flow diagram and is labelled 100.

[0042] The process 100 comprises providing a liquid hydrogenation feed 101 containing unsaturated hydrocarbons with three or more carbon atoms, as illustrated by an example in Figure 3; hydrogenating 11 of the hydrogenation feed 101 or a portion thereof in the liquid state with hydrogen 102 to obtain a hydrogenation product 103; processing 12, 13 of the hydrogenation product 103 or a portion thereof to obtain a reforming feed 105, optionally including the formation of an intermediate product 104; and reforming 14 of the reforming feed 105 with the optional addition of hydrogen 106 to obtain a reforming product 107. The reforming 14 may also include pre-reforming and steam and / or autothermal reforming. The processing 12, 13 of the hydrogenation product 103 may in particular include, and if necessary, preheating 12 and desulfurization 13 if required.

[0043] It is understood that the process 100 may also include further processing of the reforming product 107, which is initially obtained as synthesis raw gas, for example cooling, compression, drying, fractionation, water gas conversion and the like, and that components such as carbon monoxide, carbon dioxide and / or hydrogen may be converted to further process products such as ammonia, methanol, formic acid and the like.

[0044] Figure 3 illustrates, in the form of a schematic process flow diagram, the provision of the hydrogenation element 1 as it can be carried out in one of the proposed embodiments. The proposed embodiments can be implemented using the process steps illustrated in Figure 3, but also with any other process steps typical of steam cracking. It is understood that not all process steps illustrated in Figure 3 need to be implemented.

[0045] As shown in Figure 3, one or more hydrocarbons or hydrocarbon mixtures A are subjected to steam cracking 1 together with steam. The hydrocarbons are at least partially thermally cracked. One or more identical or different crackers or cracking furnaces of known type can be used for steam cracking 1.

[0046] Steam cracking 1 yields a component mixture or cracking gas B, which is subjected to quench 2. Following quench, the component mixture, now designated C, is fed to an oil removal unit 3. In the oil removal unit 3, if component C is present, pyrolysis oil D is separated from the component mixture C in one or more fractions. In the illustrated example, the pyrolysis oil D is subjected to oil stripping 4 to recover lighter compounds E separated with the pyrolysis oil D. These are returned to the oil removal unit 3. The remaining residue F of the pyrolysis oil D can be returned to the oil removal unit 3 as a reflux and provided as a product in the form of cracked oil. Additionally or alternatively, pyrolysis oil D that has not undergone oil stripping 4 can also be returned to the oil removal unit 3 as a reflux.

[0047] Any residue G of the component mixture C remaining after oil removal 3, or the entire component mixture C if no oil removal 3 takes place, is fed to a gasoline removal stage 5, the presence and design of which depend on the pyrolysis gasoline content in the component mixture C. Heavy pyrolysis gasoline H is separated in the gasoline removal stage 5. In the illustrated example, at least some of the heavy pyrolysis gasoline H is fed to a gasoline stripping stage 6 to remove lighter components. The latter can be discharged or recycled at a suitable point. A portion of the heavy pyrolysis gasoline H can be recycled back to the oil removal stage 3 before and / or after the gasoline stripping stage 6. The stripped pyrolysis gasoline obtained in the gasoline stripping stage 6, now designated I, is fed to the so-called gasoline path 7, which is not described in detail here.It may also be possible to feed a portion of the heavy pyrolysis gasoline H directly to the gasoline path 7 without stripping. Any residue K of the component mixture G remaining after gasoline removal 5, or even the entire component mixture G if no gasoline removal 5 is provided, is fed in the illustrated example to a compression stage 8, particularly a multi-stage one, the so-called raw gas compression stage, during which sour gas removal 9 can take place. Further pyrolysis gasoline L can be separated in the raw gas compression stage 6, which can, for example, also be fed to gasoline stripping 6 or directly to the gasoline path 7.

[0048] The compressed component mixture M, freed from sour gases, is fed to a fractionation unit 10, in which several fractions, exemplified here by N, are formed. The fractionation can be carried out using any suitable apparatus. The fractions N comprise, for example, fractions that predominantly or exclusively contain compounds with two, three, four, or more than four carbon atoms, or corresponding aggregate fractions, or specific hydrocarbons such as ethane or ethylene. The fractions N are then used for a suitable purpose. Their formation depends, in turn, on the hydrocarbons subjected to steam cracking 1 and thus on their corresponding concentrations in the component mixture B. Further pyrolysis gasoline O can be formed in fractionation 10, but this is advantageously not fed to gasoline stripping 6. The pyrolysis gasoline can be fed to the gasoline line 7, for example, at another point.

[0049] One of the fractions N can consist essentially of unsaturated hydrocarbons with three or more carbon atoms and, if necessary after further processing, can be used as a hydrogenation feed 1 in a process 100 illustrated in Figure 2. The process steps illustrated in Figure 3 can be part of a process 100 proposed here, which can thus provide a variety of process products.

Claims

Patent claims 1. A process (100) for producing one or more process products, wherein the process (100) comprises: Providing a liquid hydrogenation feed (101) containing unsaturated hydrocarbons with three or more carbon atoms; Hydrogenation (11) of the hydrogenation feed (101) or a part thereof in liquid state to obtain a hydrogenation product (103); Forming (12, 13) a reforming insert (105) using the hydrogenation product (103) or part thereof; and Reforming (14) the reforming charge (105) to obtain a reforming product (107), wherein the reforming (14) includes steam and / or autothermal reforming.

2. Method (100) according to claim 1, wherein the provision of the liquid hydrogenation feed (101) comprises steam cracking (1) of a hydrocarbon mixture (A) to obtain a cracking gas (B) and forming the hydrogenation feed (1) using a portion of the cracking gas (B).

3. Method (100) according to claim 2, wherein the formation of the hydrogenation insert (1) using a portion of the cracking gas (B) comprises deethanization.

4. Method (100) according to any one of the preceding claims, wherein the method (100) comprises providing one or more components of the reforming product (7) as the process product or one of the several process products.

5. Method (100) according to any one of the preceding claims, wherein the method (100) comprises converting one or more components of the reforming product (7) into the process product or one of the several process products.

6. The process (100) according to claim 5, wherein the reaction comprises the reaction of hydrogen with nitrogen to form ammonia and / or of carbon dioxide with hydrogen to form methanol.

7. A method according to any of the preceding claims, wherein the unsaturated hydrocarbons having three or more carbon atoms are contained in the hydrogenation feed (101) by up to 100 percent by weight.

8. A method according to any of the preceding claims, wherein the hydrocarbons with three or more carbon atoms comprise hydrocarbons with up to 12 carbon atoms.

9. Method according to any of the preceding claims, wherein the reforming (14) of the reforming insert (105) comprises a pre-reforming.

10. Plant for the production of one or more process products, comprising a hydrogenation reactor in which a liquid, unsaturated hydrocarbon containing three or more carbon atoms hydrogenation feed (101) can be hydrogenated to obtain a hydrogenation product (103), a processing unit (12, 13) for the formation of a reforming feed (105) using the hydrogenation product (103), and a reforming unit (14) with a steam and / or an autothermal reformer for reforming the reforming feed (105) to obtain a reforming product (107).

11. System according to claim 10, wherein the system is configured to carry out a method according to any one of claims 1 to 9.

Images