PROCESS FOR ADSORBER REGENERATION

Abstract

Disclosed is a process for the regeneration of an adsorber. For the regeneration a liquid stream (S2) is applied which is obtained by hydrogenation of a stream (S1) comprising at least one alkane and least one olefin. The stream (S2) comprises one alkane and a reduced amount of at least one olefin compared to the amount in the stream (S1). Then the stream (S2) is converted from the liquid into the gaseous phase and the adsorber is regenerated by contact with the gaseous stream (S2).

Claims

1-15. (canceled)

16. A process for the regeneration of an adsorber, comprising: a) hydrogenating a stream (S1) comprising at least one alkane and at least one olefin to obtain a liquid stream (S2) comprising at least one alkane and a reduced amount of at least one olefin compared to the amount in the stream (S1), b) converting the stream (S2) from liquid phase into gaseous phase, and c) regenerating the adsorber by contact with the gaseous stream (S2) obtained in b).

17. The process according to claim 16, wherein the stream (S1) comprises at least one alkane and at least one olefin in a total of at least 99 wt-%.

18. The process according to claim 16, wherein in a), i) the stream (S1) comprises butane and butene, or ii) the amount of olefins containing more than one olefinic double bond in stream (S1) is lower than 500 ppm, or iii) the stream (S2) comprises not more than 1000 wt-ppm olefin, or iv) the stream (S2) comprises at least 99 wt-% of at least one alkane.

19. The process according to claim 18, wherein i) the stream (S1) comprises at least 96 wt-% butane and not more than 4 wt-% butane, or ii) the stream (S2) comprises at least 99 wt-% of butane.

20. The process according to claim 16, wherein the absorbent in the adsorber is based on aluminium oxide or the absorber can be employed for the adsorption of compounds containing oxygen or sulphur out of organic compositions.

21. The process according to claim 20, wherein the absorber can be employed for the adsorption of ethers, alcohols, thiols, thioethers, sulfoxides, ketones, aldehydes, or mixtures thereof.

22. The process according to claim 16, wherein in b) the conversion is carried out by lowering the pressure or heating of the liquid stream (S2).

23. The process according to claim 22, wherein the conversion is carried out by employing at least one evaporator or at least one superheater or at least one flash vessel.

24. The process according to claim 16, wherein in c) the regeneration of the adsorber is carried out at a temperature in the range of 230 to 270° C., or by passing the gaseous stream (S2) through a device containing the adsorber.

25. The process according to claim 16, wherein prior to carrying out c) a draining d) is carried out in order to at least partially remove an organic composition which was passed through the adsorber during its operation mode.

26. The process according to claim 16, wherein c) comprises at least one of the following c1) to c5): c1) heating the adsorber by contact with the gaseous stream (S2), wherein the gaseous stream (S2) is condensed within the adsorber, c2) heating the adsorber by contact with the gaseous stream (S2) up to a temperature in the range of 230 to 270° C. without any condensation of the gaseous stream (S2) within the adsorber, c3) regeneration of the absorber at a temperature in the range of 230 to 270° C. by contact with the gaseous stream (S2), c4) cooling of the absorber by contact with the gaseous stream (S2) to a temperature in the range of 80-120° C., or c5) cooling of the absorber by contact with the liquid stream (S2) obtained in a) to a temperature below 80° C.

27. The process according to claim 26, wherein d) is carried out prior to c) and c) comprises the c1), followed by c2), followed by c3), followed by c4) and followed by c5).

28. The process according to claim 26, wherein the condensate obtained in c1) contains the stream (S2) and the residue of the organic composition which was not removed from the adsorber when carrying out draining d), and the condensate is optionally collected in a device in order to pass the collected condensate through an adsorber during its operation mode.

29. The process according to claim 26, wherein the flow direction of the gaseous stream (S2) through the adsorber in c1), c2) or c3) is opposite to the flow direction of any organic composition through the same adsorber during its operation mode, or the gaseous stream (S2) in c4) or the liquid stream (S2) in c5) have the same flow direction through the adsorber as the flow direction of any organic composition through the same adsorber during its operation mode.

30. The process according to claim 16, wherein i) the heating rate of the adsorber does not exceed 60° C./h, or ii) the temperature of the gaseous stream (S2) is not more than 100° C., higher than the temperature of the adsorber, or iii) the temperature of the gaseous or optionally liquid stream (S2) is not more than 100° C., lower than the temperature of the adsorber.

31. The process according to claim 16, wherein i) subsequent to c), the outflow obtained from the absorber, comprising gaseous stream (S2) and the impurities removed from the adsorber, is condensed, or ii) after finishing the regeneration of the adsorber according to c), the adsorber is switched into its operation mode by feeding it with an organic composition to be purified.

32. The process according to claim 16, wherein the adsorber to be regenerated in c) is part of an assembly which contains at least one further adsorber.

33. The process according to claim 32, wherein the at least one further adsorber is under its operation mode during the regeneration of the first adsorber, or each adsorber within this assembly is identical in respect of the adsorbent and its operation mode.

34. The process according to claim 16, wherein the stream (S1) originates from an organic composition which has been earlier purified by the same adsorber or by a similar further adsorber during the operation mode of the respective adsorber.

35. The process according to claim 34, wherein an oligomerization of olefins, or a distillation to separate butane from butene is carried out prior to a) and after the purification of the organic composition employing at least one adsorber in its operation mode.

36. The process according to claim 35, wherein the oligomerization is a dimerization of butene to octane.

Description

FIGURES

[0134] The FIGS. 1 to 4 illustrate certain aspects of the invention. For the sake of clarity not all applicable components and embodiments are drawn in one and/or all figures. Embodiments shown in different figures may be combined with each other and do not exclude the incorporation of further components within the limits of the disclosure of the specification.

[0135] FIG. 1 illustrates the most basic assembly of the present invention. According to step a) of the process of the present invention a stream (S1) is fed into the hydrogenation reactor (HR). The stream (S1) is converted in the hydrogenation reactor (HR) into the stream (S2) and routed through the evaporation/heating unit (EHU) in order to be converted from the liquid into the gaseous phase. Then the adsorber (A) is regenerated by contact with gaseous stream (S2) coming from the evaporation/heating unit (EHU). The stream (S4) is leaving adsorber (A) during regeneration mode but not during operation mode of the adsorber (A). The stream (S4) comprises at least the stream (S2) and/or compounds containing oxygen and/or sulphur and/or optionally some residue of organic composition. The streams (S3) and (S5) are only present during operation mode. The stream (S3) comprises organic composition and compounds containing oxygen and/or sulphur. The stream (S5) comprises organic composition and no compounds containing oxygen and/or sulphur or a lower amount of compounds containing oxygen and/or sulphur than stream (S3). Stream (S5) is leaving adsorber (A) on the opposite end of adsorber (A), chosen for the introduction of stream (S3) into the adsorber (A). In other words, stream (S4) usually additionally comprises (compared to stream (S2)) those elements (such as compounds containing oxygen and/or sulphur) which were adsorbed by the adsorber from stream (S3) during its operation mode.

[0136] FIG. 2 demonstrates one possible embodiment for evaporation/heating unit (EHU). Liquid stream (S2) is fed into a flash vessel (FV) and routed from there directly and/or indirectly over an evaporator (EV) to a super-heater (SH). Coming from super-heater (SH) stream (S2) can be fed into adsorber (A) opposite or according to the direction of the flow of stream (S3).

[0137] Besides the possible set-ups shown in FIG. 1 and FIG. 2, in FIG. 3 further optional components are displayed; a buffer vessel (BV), connected over stream (S6) with adsorber (A) and a cooling unit (CU) for cooling for example of the streams (S4). Stream (S6) can be routed in any direction between at least adsorber (A) and buffer vessel (BV). Stream (S6) comprises at least organic composition and/or stream (S2) and/or compounds containing oxygen and/or sulphur. Cooling unit (CU) comprises at least one cooler and/or condenser which are serially connected and/or parallel-connected with each other.

[0138] FIG. 4 shows an embodiment of the invention employing at least two adsorbers (A1) and (A2). The set-up makes it possible to run one adsorber in operation mode and the other in parallel in regeneration mode. In this case stream (S3) is fed only into the adsorber in operation mode and stream (S2) is only fed into the adsorber in regeneration mode. Consequently, stream (S4) is only leaving the adsorber in regeneration mode and stream (S5) is only leaving the adsorber in operation mode.