METHOD AND SYSTEM COMBINATION FOR THE PREPARATION OF SYNTHESIS PRODUCTS CONTAINING NITROGEN

Abstract

The invention relates to a process (100), in which, with the inclusion of an air-separation method (10), an oxygen-rich substance flow (b) is formed, which, with a methane-rich substance flow (e), is subjected to a method for oxidative methane coupling. From the product flow (e) of the method for oxidative coupling of methane (20), one or more substance flows (f, i) are formed, which are subjected to one or more synthesis methods (40, 50) for the production of one or more nitrogen-containing synthesis products.

Claims

1. A process, in which, with the inclusion of an air-separation method, an oxygen-rich substance flow is formed, which is subjected, with a methane-rich substance flow, to a method for oxidative coupling of methane, characterised in that, from a product flow of the method for oxidative coupling of methane, a hydrogen-rich substance flow and/or a carbon-dioxide-rich substance flow are formed, and that the substance flow or flows formed from the product flow are subjected to one or more synthesis methods for the production of one or more nitrogen-containing synthesis products.

2. The process according to claim 1, in which, with the inclusion of the air-separation method, furthermore, a nitrogen-rich substance flow is formed, wherein the nitrogen-rich substance flow is subjected to the, or to one of the, synthesis methods.

3. The process according to claim 1, in which the hydrogen-rich substance flow is formed, wherein the, or one of the, synthesis methods is an ammonia-synthesis method, to which the hydrogen-rich substance flow is subjected.

4. The process according to claim 3, in which the methane-rich substance flow contains nitrogen, wherein the nitrogen contained in the methane-rich substance flow is partially or completely transferred into the hydrogen-rich substance flow and, within the latter, subjected to the ammonia-synthesis method.

5. The process according to claim 4, in which the methane-rich substance flow contains up to 20 mole percent nitrogen.

6. The process according to any one of claim 3, in which the oxygen-rich substance flow contains nitrogen, wherein the nitrogen contained in the oxygen-rich substance flow is partially or completely transferred into the hydrogen-rich substance flow and, within the latter, subjected to the ammonia-synthesis method.

7. The process according to claim 6, in which the oxygen-rich substance flow contains up to 20 mole percent nitrogen.

8. The process according to claim 1, in which carbon-dioxide-rich substance flow is formed, wherein the, or one of the, synthesis methods is a urea synthesis method, to which the carbon-dioxide-rich substance flow is subjected.

9. The process according to claim 1, in which, from the product flow, furthermore, one or more olefin-rich substance flows are formed, and, with the inclusion of an air separation method, one or more further oxygen-rich substance flows are formed, wherein the olefin-rich substance flow or flows and/or the further oxygen-rich substance flow or flows are subjected to an epoxidation method.

10. The process according to claim 1, in which, from the product flow, at least one further substance flow is formed, which, is again subjected to the method for oxidative coupling of methane.

11. The process according to claim 1, in which the waste heat of the method for oxidative methane coupling is used for the pre-heating or heating of one or more substance flows and/or of one or more reactors, which are used in the synthesis method for the production of the nitrogen-containing synthesis product or products.

12. The process according to claim 4, in which the methane-rich substance flow contains from 5 to 10 mole percent nitrogen.

13. The process according to claim 6, in which the oxygen-rich substance flow contains from 5 to 10 mole percent nitrogen.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0031] FIG. 1 shows a process for manufacturing reaction products according to a particularly preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWING

[0032] In FIG. 1, a process according to a particularly preferred embodiment of the invention is illustrated in the form of a schematic process-flow diagram and designated as a whole as 100.

[0033] The process 100 comprises an air-separation method 10 and a method for oxidative coupling of methane 20. Feedstock air in the form of a substance flow a is supplied to the air-separation method 10. Air-separation methods 10 suitable for use within the scope of the process 100 have been described extensively elsewhere.

[0034] With the use of a corresponding air-separation method 10 in the illustrated example, an oxygen-rich substance flow b and a nitrogen-rich substance flow c are provided. However, with the use of the air-separation method 10, arbitrary further substance flows, which can comprise air-separation products, can also be provided, for example, further oxygen-rich and/or nitrogen-rich substance flows and/or substance flows which are rich in one or more noble gases, as is known in principle.

[0035] In the illustrated example, the oxygen-rich substance flow b and a methane-rich substance flow d, which can be, for example, conditioned or unconditioned natural gas, are supplied to the method for oxidative coupling of methane 20. In the method for oxidative coupling of methane 20, a product flow e is produced, which can contain, inter alia, unconverted methane of the substance flow d, unconverted oxygen of the substance flow b, inert gases such as nitrogen optionally contained in the substance flow d, and reaction products of the oxidative coupling of methane, such as hydrogen, carbon dioxide, ethylene or propylene.

[0036] The product flow e is subjected to a separation method 30, which can comprise non-cryogenic and cryogenic separation steps. In particular, the separation method 30 can also comprise a gas scrubbing. With the use of the separation method 30, in particular, a hydrogen-rich substance flow f, an ethylene-rich substance flow g, a propylene-rich substance flow h and a carbon-dioxide-rich substance flow i can be provided. The hydrogen-rich substance flow f, the propylene-rich substance flow g and the ethylene-rich substance flow h are typically produced in one or more cryogenic separation steps of the separation method 30. The carbon-dioxide-rich substance flow i is typically separated in advance. In the separation method 30 or respectively in corresponding separation steps, further substance flows can also be provided, which have, however, not been shown in FIG. 1 for the sake of visual clarity.

[0037] The core of the process 100 in the particularly preferred embodiment shown in FIG. 1 is the implementation of an ammonia-synthesis method 40, to which the nitrogen-rich substance flow c, which is prepared with the use of the air-separation method 10, and the hydrogen-rich substance flow f, which is prepared with the use of the method for oxidative coupling of methane and the downstream separation method 30, are supplied in the illustrated example. It should be emphasised that, with the use of the method for oxidative coupling of methane 20 or respectively of the downstream separation method 30, further hydrogen-rich flows can also be provided, which need not necessarily be supplied in their entirety to the ammonia-synthesis method 40. Similarly, the nitrogen supplied to the ammonia synthesis method 40 need not originate or need not originate exclusively from the nitrogen-rich substance flow c from the air-separation method 10. At least a part of the nitrogen can also be contained in the hydrogen-rich substance flow f, as explained above.

[0038] With the use of the ammonia-synthesis method 40 in the example shown, two ammonia-rich flows k and l are provided. By contrast with the particularly preferred embodiment of the process 100 according to the invention shown in FIG. 1, ammonia can also represent a single nitrogen-containing end-product of a corresponding process. In this case, further method steps for the conversion of ammonia, as are implemented in FIG. 1 and explained in the following, are dispensed with.

[0039] However, the particularly preferred embodiment of the process 100 shown in FIG. 1, comprises a urea synthesis method 50. In this context, the ammonia-rich flow l, which is provided with the use of the ammonia-synthesis method 40, and the carbon-dioxide-rich flow i, which is provided with the use of the method for oxidative coupling of methane 20 and the downstream separation method 30, are supplied to the urea-synthesis method 50. It goes without saying that the entire ammonia formed in the ammonia-synthesis step 40 and/or the entire carbon dioxide provided in the method for oxidative coupling of methane 20 and the downstream separation method 30 need not be supplied to the urea-synthesis method 50. In each case, only partial quantities of the named compounds can also be used; the remainder can be supplied from a corresponding process 100, for example, as a product or respectively by-product. A corresponding case is shown in FIG. 1 with the ammonia-rich substance flows k and l.

[0040] In the illustrated example, the ammonia-rich substance flow k is output from the process. With the use of the urea-synthesis method 50 in the particularly preferred embodiment of the invention shown in FIG. 1, a urea-rich substance flow m is provided and supplied as required to suitable conditioning steps.

[0041] The methods explained in the following are also not necessarily a component of a corresponding process 100. This means that the propylene-rich substance flow g and/or the ethylene-rich substance flow h can also be output from a corresponding process 100, in each case.

[0042] In the illustrated example, an epoxidation method 60 is shown, which can also be provided separately for the propylene-rich substance flow g and the ethylene-rich substance flow h or only for one of these substance flows. An oxygen-rich substance flow n, which can, in particular, be provided with the use of the air-separation method 10, is supplied to the epoxidation method 60. With the use of the epoxidation method 60, a propylene-oxide-rich substance flow o and/or an ethylene-oxide-rich substance flow p can be provided. Here also, the entire propylene and or ethylene provided in the method for oxidative coupling of methane 20 or respectively the downstream separation method 30 need not be subjected to the epoxidation method 60. In particular, partial flows of corresponding propylene or respectively ethylene can be output from the process 100 as products.