METHOD AND SYSTEM FOR PRODUCING ONE OR MORE OLEFINS

Abstract

A process (100) is proposed for the production of one or more olefins, in which a reaction feed containing oxygen and one or more paraffins is formed and in which a part of the oxygen in the reaction feed is reacted with a part of the one or more paraffins to form the one or more olefins by an oxidative process, to obtain a process gas, the process gas containing at least the unreacted part of the one or more paraffins and oxygen, the one or more olefins, one or more acetylenes, carbon dioxide and water. The process comprises subjecting the process gas or a gas mixture formed using at least a part of the process gas partially or completely to a condensate separation (2), a compression (3), an at least partial removal (4) of the oxygen and acetylene(s) and to one or more stages of a carbon dioxide removal (5) in the order given herein, wherein the at least partial removal (4) of the oxygen and of the acetylene(s) is performed at the same time and by a catalytic conversion using a catalyst comprising copper oxide or ruthenium, and wherein the catalytic conversion is performed at least in part in the form of a hydrogenation. A corresponding plant is also the subject of the present invention.

Claims

1. A process (100) for producing one or more olefins, in which a reaction feed is formed which contains oxygen and one or more paraffins, and in which a part of the oxygen in the reaction feed is reacted with a part of the paraffin(s) to form the olefin(s) by an oxidative process, in particular by oxidative dehydrogenation (1) or oxidative coupling of methane, to obtain a process gas, the process gas comprising at least the unreacted part of the paraffin(s) and the oxygen, the olefin(s), one or more acetylenes, carbon dioxide and water, characterised in that the process comprises subjecting the process gas or a gas mixture formed using at least a part of the process gas, in the order indicated herein, partially or completely to a condensate separation (2), a compression (3), an at least partial removal (4) of the oxygen and the acetylene(s) and to one or more stages of carbon dioxide removal (5), wherein the at least partial removal (4) of the oxygen and of the acetylene(s) is performed at the same time and by a catalytic conversion using a catalyst comprising copper oxide or ruthenium, and wherein the catalytic conversion is performed at least in part in the form of a hydrogenation.

2. The process (100) according to claim 1 wherein the at least partial removal (4) of oxygen and the acetylene(s) is carried out downstream of one or more stages of a carbon dioxide removal (5) and upstream of one or more further stages of the carbon dioxide removal (5).

3. The process (100) according to claim 1, in which downstream of the at least partial removal of the oxygen and the acetylene(s), a drying (6) and one or more separation steps (7) are carried out.

4. The process (100) according to claim 1, in which the catalyst containing copper oxide is used and the at least partial removal (4) of the oxygen and the acetylene(s) is carried out under reaction conditions comprising a temperature of 180 to 360° C., a pressure of 1 to 30 bar abs., an hourly gas space velocity of 1,000 to 15,000 h.sup.−1 and a ratio of hydrogen to oxygen of 0 to 5.

5. The process (100) according to claim 1, in which the ruthenium-containing catalyst is used and the at least partial removal (4) of the oxygen and the acetylene(s) is carried out under reaction conditions which comprise a temperature of 120 to 360° C., a pressure of 1 to 30 bar abs., an hourly gas space velocity of 1,000 to 15,000 h.sup.−1 and a hydrogen/oxygen ratio of 0 to 5.

6. The process (100) according to claim 1, in which the at least partial removal (4) of the oxygen and the acetylene(s) is carried out with the addition of hydrogen.

7. The process (100) according to claim 1, in which the at least partial removal (4) of the oxygen and the acetylene(s) is carried out isothermally or at least in one step adiabatically.

8. The process (100) according to claim 1, wherein the oxidative dehydrogenation is carried out as oxidative dehydrogenation of ethane.

9. A plant for the production of one or more olefins, which is arranged to form a reaction feed containing oxygen and one or more paraffins, and which is arranged to react a part of the oxygen in the reaction feed with a part of the paraffin(s) to form the olefin(s) by an oxidative process, in particular by oxidative dehydrogenation (1) or oxidative methane coupling, to obtain a process gas, wherein the process gas contains at least the unreacted part of the paraffin(s) and oxygen, the olefin(s), one or more acetylenes, carbon dioxide and water, characterized in that the plant is configured to subject the process gas partially or completely, in the order indicated herein, to a condensate separation (2), a compression (3), an at least partial removal (4) of the oxygen and the acetylene(s) and to one or more stages of a carbon dioxide removal (5), wherein for the at least partial removal (4) of the oxygen and the acetylene(s) at the same time and by a catalytic conversion a catalyst comprising copper oxide or ruthenium is provided which is adapted to catalyze the catalytic conversion at least in part in the form of a hydrogenation.

10. The plant according to claim 9, which is configured to carry out a process (100) for producing one or more olefins, in which a reaction feed is formed which contains oxygen and one or more paraffins, and in which a part of the oxygen in the reaction feed is reacted with a part of the paraffin(s) to form the olefin(s) by an oxidative process, in particular by oxidative dehydrogenation (1) or oxidative coupling of methane, to obtain a process gas, the process gas comprising at least the unreacted part of the paraffin(s) and the oxygen, the olefin(s), one or more acetylenes, carbon dioxide and water, characterised in that the process comprises subjecting the process gas or a gas mixture formed using at least a part of the process gas, in the order indicated herein, partially or completely to a condensate separation (2), a compression (3), an at least partial removal (4) of the oxygen and the acetylene(s) and to one or more stages of carbon dioxide removal (5), wherein the at least partial removal (4) of the oxygen and of the acetylene(s) is performed at the same time and by a catalytic conversion using a catalyst comprising copper oxide or ruthenium, and wherein the catalytic conversion is performed at least in part in the form of a hydrogenation.

Description

DESIGN EXAMPLES

[0059] FIG. 1 illustrates a method according to a particularly preferred embodiment of the present invention and is designated 100 in total. The explanations regarding process 100 apply equally to a corresponding plant in which the process steps shown in FIG. 1 are realised by corresponding plant components.

[0060] In process 100, a reaction feed containing oxygen and one or more paraffins is formed and subjected to oxidative dehydrogenation 1 in the form of a material stream a. A process gas formed in the oxidative dehydrogenation is at least partially fed to a condensate separation 2, in which, for example, water and acetic acid are condensatively separated. The corresponding process gas or its part is fed to the condensate separation in the form of a process gas stream b.

[0061] The process gas removed from the condensate separation and depleted in water and possibly other components is fed in the form of a process gas flow c to a process gas compressor or raw gas compressor 3 and compressed there to a pressure level of, for example, more than 15 bar. The compressed process gas stream is fed in the form of a material flow d to an at least partial removal 4 of oxygen and acetylenes, in which both acetylenes and oxygen are reacted by setting certain reaction conditions. The correspondingly treated process gas is subjected to carbon dioxide separation 5 in the form of a process gas stream e, then passes through a drying process 6 in the form of a process gas stream f and finally is subjected to one or more further separation steps 7 in the form of a process gas stream g, which are shown here in a highly simplified form. In the separation step(s) 7, one or more fractions h, i are formed and carried out from process 100.

[0062] Basically, procedure 100, which is illustrated in FIG. 1, can be implemented in different ways. In particular, process steps 5 to 7 can be carried out in a different arrangement, partial streams or fractions can be recirculated and the like. The embodiment of the present invention was repeatedly explained.

[0063] According to Example 1, a commercially available catalyst consisting of copper and manganese oxide supported on alumina was examined for its suitability for use in the removal of oxygen and acetylene from a process gas of the ODH or ODH-E. The catalyst was crushed to 3 mm and filled into a tubular reactor with an inner diameter of 29 mm. Glass beads were filled in as inert material above the catalyst bed. A catalyst bed of 15 cm was realized. The reactor was operated as an adiabatic tube reactor and was heated via heating bands to compensate for heat losses. Gas mixtures with the composition (in volume percent) given in Table 1A were fed in via mass flow controllers:

TABLE-US-00001 TABLE 1A Gas mixture 1 Gas mixture 2 Hydrogen 0 0.66 Ethylene 35.9 35.9 Acetylene 0.015 0.015 Ethane 59.1 52.5 Oxygen 0.47 0.47 Nitrogen 1.77 7.7 Carbon monoxide 2.72 2.72

[0064] Tables 1B and 10 show the successful simultaneous removal of oxygen and acetylene over a running time of more than 250 hours for the two gas mixtures listed in Table 1A. Between 158.8 hours and 179.2 hours, switching was performed between gas mixture 1 and 2 according to Table 1A, i.e. hydrogen was also added. Both tables 1B and 10 therefore relate to a continuous test.

[0065] The reaction conditions used were an hourly gas hourly space velocity (GHSV) of approx. 3,700 h-1, a reactor inlet temperature of 230° C. and a pressure of 20 bar. It is shown that oxygen can be removed both by oxidation of carbon monoxide (in the absence of hydrogen, gas mixture 1) and by hydrogenation (gas mixture 2). The ethylene losses are extremely low in each case.

TABLE-US-00002 TABLE 1B (gas mixture 1 according to Table 1A) Running time h 4.7 58.6 118.5 140.1 158.8 Ethylene loss % 1.9 0.15 0.08 0.28 0.05 Oxygen conversion % 100 100 100 100 100 Acetylene conversion % 100 100 100 100 100

TABLE-US-00003 TABLE 1C (gas mixture 2 according to Table 1A) Running time h 179.2 199.2 226.2 254.1 Ethylene loss % 0.00 0.00 0.00 0.00 Oxygen conversion % 99.8 100 100 100 Acetylene conversion % 100 100 100 100

[0066] In a Comparative Example 1, the same test set-up as in example 1 was used and the same GHSV was applied. However, only a reactor inlet temperature of 170° C. was used. As shown in FIG. 2, the catalyst is deactivated very quickly under these conditions and the conversion of oxygen decreases. FIG. 2 shows a test time in hours on the abscissa versus a conversion to molar percent on the ordinate. The reaction of oxygen is illustrated with 201 and the reaction of acetylene with 202.

[0067] According to example 2, a sample of a commercially available catalyst with ruthenium supported on alumina was examined. The balls (2 to 4 mm diameter) were filled into a tubular reactor with an inner diameter of 29 mm. Glass beads were filled in as inert material above the catalyst bed. A catalyst bed of 20 cm was realized. The reactor was heated by heating bands. The reactor is operated as an adiabatic tube reactor. A gas mixture with the composition (in volume percent) given in Table 2A was fed in via mass flow controllers:

TABLE-US-00004 TABLE 2A Gas mixture Hydrogen 2.06 Ethylene 34.70 Acetylene 0.017 Ethane 39.20 Oxygen 0.49 Nitrogen 30.65 Carbon monoxide 2.89

[0068] Table 2B shows the successful simultaneous removal of oxygen and acetylene at different conditions. A pressure of 20 bar was set in the reactor.

TABLE-US-00005 TABLE 2B GHSV h-1 2084 4340 4297 2510 Input temperature ° C. 152 150 189 152 Ethylene loss % 1.9 0.7 0.1 0.8 Oxygen conversion % 99.2 97.7 97.3 96.9 Acetylene conversion % 100 100 100 100

[0069] In a Comparative Example 2, the same catalyst as in example 2 was tested in the same experimental apparatus with a catalyst bed of 30 cm. The gas mixtures shown in Table 2C (figures in volume percent) were adjusted.

TABLE-US-00006 TABLE 2C Gas mixture 1 Gas mixture 2 Gas mixture 3 Hydrogen 8.36 7.82 12.41 Ethylene 37.30 35.13 35.31 Acetylene 0.016 0.007 0.015 Ethane 48.90 53.37 45.43 Oxygen 0.44 0.502 0.732 Nitrogen 2.05 1.95 3.32 Carbon monoxide 2.92 1.22 2.77

[0070] In Comparative Example 2, a pressure of 24 bar was used. The results for the three gas mixtures given in Table 2C are shown in Table 2D. As can be seen from Table 2D, ethylene losses are very high under the specified conditions, especially at the high hydrogen/oxygen ratio.

TABLE-US-00007 TABLE 2D Mixture 1 Mixture 2 Mixture 3 GHSV h-1 1927 2449 1961 Input temperature ° C. 185.5 155 158.5 Ethylene loss % 3.2 4.2 5.5 Oxygen turnover % 100 100 100 Acetylene sales % 98.7 99.1 99.6