PRODUCT RECOVERY PROCESS FOR ADSORBER REGENERATION

Abstract

Disclosed is a process for the regeneration of an adsorber (A1). The adsorber (A1) is regenerated by contact with a gaseous stream (S2) and the outflow of the adsorber (A1) comprising condensate of stream (S2) and organic composition (OC1) collected in a device. After regeneration of the adsorber (A1) the stream (S2) in the adsorber (A1) is replaced completely or at least partially by the content of the device. Then the adsorber (A1) is fed with organic composition comprising at least one olefin, at least one alkane and at least one compound containing oxygen and/or sulfur.

Claims

1. A process for the regeneration of an adsorber (A1) comprising the following steps a) to d): a) regenerating the adsorber (A1) by contact with a gaseous stream (S2) comprising at least one alkane, b) collecting the outflow of the adsorber (A1) in a device (Dl), wherein the outflow comprises condensate of stream (S2) and an organic composition (OC1) comprising at least one olefin, at least one alkane and optionally at least one compound containing oxygen or sulfur, c) replacing the stream (S2) in the adsorber (A1) completely or at least partially by the content of the device (D1), d) feeding the adsorber (A1) with an organic composition (OC2) comprising at least one olefin, at least one alkane and at least one compound containing oxygen or sulfur.

2. The process according to claim 1, comprising the further steps e) or f): e) hydrogenation of a stream (S1) comprising at least one alkane and at least one olefin, carried out prior to step a), to obtain a liquid or gaseous stream (S2), or converting, prior to step a), the liquid stream (S2) into gaseous phase.

3. The process according to claim 1, wherein i) in step e), the stream (S1) comprises butane and butene or ii) the stream (S2) comprises not more than 1000 wt-ppm olefin, or iii) the stream (S2) comprises at least 99 wt-% of at least one alkane, or iv) the organic composition (OC2) in step d) comprises not more than 1000 wt-ppm of compounds containing oxygen or sulfur, or v) the load of the adsorber (A1) with organic composition (OC2) in step d) is increased gradually, or vi) the organic composition (OC2) is routed through the device (D1) before being fed into the adsorber (A1) according to step d).

4. The process according to claim 2, wherein the stream (S1) originates from the organic composition (OC2) which has been purified earlier by the same adsorber (A1) or by a similar further adsorber during the operation mode of the respective adsorber.

5. The process according to claim 4 wherein an oligomerization of olefins, or a distillation step to separate butane from butene is carried out prior to step e) and after the purification of the organic composition (OC2) employing at least one adsorber in its operation mode.

6. The process according to claim 1, wherein prior to carrying out step a) a draining step g) is carried out in order to at least partially remove an organic composition (OC1) which was purified by the adsorber (A1) during its operation mode, optionally the organic composition (OC1) obtained in the draining step g) is collected in a device (D1).

7. The process according to claim 1, wherein step a) comprises component step al) and at least one of the further following component steps a2) to a5): a1) heating the adsorber (A1) by contact with the gaseous stream (S2), wherein the gaseous stream (S2) is condensed within the adsorber (A1), a2) heating the adsorber (A1) 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 (A1), a3) regeneration of the adsorber (A1) at a temperature in the range of 230 to 270° C. by contact with the gaseous stream (S2), a4) cooling of the adsorber (A1) by contact with stream (S2) in gaseous state, to a temperature in the range of 80° C. to 120° C., or a5) cooling of the adsorber (A1) by contact with stream (S2) in liquid state to a temperature below 80° C.

8. The process according to claim 7 wherein the flow direction of the gaseous stream (S2) through the adsorber (A1) in steps a1), a2), a3) or b) is opposite to the flow direction of any organic composition through the same adsorber (A1) during its operation mode, or the gaseous stream (S2) in step a4) or the liquid stream (S2) in step a5) have the same flow direction through the adsorber (A1) as the flow direction of any organic composition through the same adsorber (A1) during its operation mode.

9. The process according to claim 1, wherein the adsorber (A1) is based on aluminum oxide or the absorber adsorber (A1) can be employed for the adsorption of compounds containing oxygen or sulfur out of organic compositions.

10. The process according to claim 2, comprising the step f), wherein in step f) the conversion is carried out by lowering the pressure or heating of the liquid stream (S2).

11. The process according to claim 1, wherein i) the heating rate of the adsorber (A1) does not exceed 60° C./h, or ii) the temperature of the gaseous stream (S2) is not more than 100° C., preferably not more than 60° C., higher than the temperature of adsorber (A1), 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.

12. The process according to claim 1, wherein in step a), the outflow obtained from the adsorber (A1), comprising gaseous stream (S2) and the impurities removed from the adsorber (A1) is condensed at least partially.

13. The process according to claim 1, wherein the adsorber (A1) to be regenerated in step a) and b) is part of an assembly which comprises at least one further adsorber (A2).

14. The process according to claim 13, wherein the at least one further adsorber (A2) is in operation mode and i) in step d) the load of the further adsorber (A2) with organic composition (OC2) is gradually decreased at the same rate as the load of the first adsorber (A1) with organic composition (OC2) according to step d) is gradually increased, or ii) in step d) the first adsorber (A1) and the at least one further adsorber (A2) are run with identical loads of organic composition (OC2) according to step d), then the at least one further adsorber (A2) is switched to regeneration mode.

15. The process according to claim 1, wherein i) in step c), if stream (S2) and organic composition (OC1) form at least two separated compositions or phases, the composition or phase in the device (D1) with the higher content of organic composition (OC1) is the content of the device (D1) in step c) replacing the stream (S2) in the adsorber (A1), or ii) the part of stream (S2) in the adsorber (A1) which is replaced in the adsorber (A1) by a part of content of the device (D1) in step c) is collected in the device (D1).

16. The process according to claim 3, wherein i) the stream (S2) comprises at least 99 wt-% of butane, or ii) in step e), the stream (S1) comprises at least 96 wt-% butane and not more than 4 wt-% butene.

17. The process according to claim 5, wherein the oligomerization is a dimerization of butene to octene.

18. The process according to claim 7, wherein step g) is carried out prior to step a), step b) is carried out at the same time as step a), and step a) comprises the component steps a1), followed by a2), followed by a3) followed by step a4) followed by a5).

19. The process according to claim 9, wherein the adsorber (A1) can be employed for the adsorption of ethers, alcohols, thiols, thioethers, sulfoxides, ketones, aldehydes or mixtures thereof.

20. The process according to claim 10, wherein the conversion is carried out by employing at least one evaporator (EV1) or at least one super-heater (SH1) or at least one flash vessel (FV1).

21. The process according to claim 13, wherein the at least one further adsorber (A2) is under its operation mode during the regeneration of the first adsorber (A1) or each adsorber within this assembly is identical in respect of the adsorbent or its mode of operation.

Description

FIGURES

[0155] 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.

[0156] 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.

[0157] FIG. 1 illustrates the most basic assembly of the present invention. The adsorber (A1) is regenerated by contact with gaseous stream (S2) fed into the adsorber in opposite direction to the direction of flow of stream (OC2). Stream (S2) can alternatively be fed into the adsorber (A1) according to the direction of flow of stream (OC2) during other steps of the regeneration process. Stream (OC2) comprises organic composition (OC2). Stream (OC1) is leaving adsorber (A1) on the opposite end of adsorber (A1), chosen for the introduction of stream (OC2) into the adsorber (A1). Stream (OC1) comprises organic composition (OC1). Stream (OC2) can be fed directly into the adsorber (A1) or prior routed through device (D1). The streams (OC1) and (OC2) are only present during operation mode. The stream (S3) may comprise organic composition (OC1) and/or stream (S2) and/or stream (OC2). Stream (S3) is either collected in a device (D1) or transferred from the device (D1) to the adsorber (A1). During step a) according to claim 8 or when stream (S3) is transferred to the adsorber (A1) another stream (S2) at the opposite end of the adsorber (A1) compared to the side connected to the device (D1) can occur. In one embodiment of the invention, this stream (S2) can, if occurring during the transfer of stream (S3) to the adsorber (A1), optionally be routed to the device (D1). The stream (S4) comprises at least the stream (S2) and/or compounds containing oxygen and/or sulfur. The stream (S4) is leaving adsorber (A1) during regeneration mode, in regeneration step a) of the process of the present invention, but not during operation mode of the adsorber (A1). Stream (S4) may leave the adsorber according to or opposite to the direction of flow of stream (OC2). Preferably stream (S4) leaves the adsorber during the steps a1), a2) and/or a3) opposite to the direction of flow of stream (OC2) and/or during the steps a4) and/or a5) according to the direction of flow of stream (OC2). Stream (S4) may additionally comprise (compared to stream (S2)) those elements (such as compounds containing oxygen and/or sulphur) which were adsorbed by the adsorber from stream (OC2) during its operation mode.

[0158] FIG. 2 demonstrates one possible embodiment, in which liquid stream (S2) is obtained by hydrogenation of stream (S1). The stream (S1) is fed into a hydrogenation reactor (HR). The outflow comprises liquid stream (S2) which is routed to the evaporation/heating unit (EHU).

[0159] In FIG. 3 demonstrates one possible embodiment for evaporation/heating unit (EHU). Liquid stream (S2) is fed into a flash vessel (FV1) and routed from there directly and/or indirectly over an evaporator (EV1) to a super heater (SH1). Coming from super heater (SH1) stream (S2) can be routed to the adsorber (A1) as illustrated for example in FIG. 1.

[0160] FIG. 4 shows a further alternative embodiment, using two adsorbers (A1) and (A2) in parallel. The adsorbers can be operated simultaneously in the same mode or one in regeneration mode and the other in operation mode.