A modular portable regeneration system for PSA adsorber and in-SITU regeneration process of PSA adsorber

Abstract

The present invention relates to a modular portable regeneration system for a pressure swing adsorption (PSA) adsorber bed. The present invention provides a modular hot nitrogen-based regeneration system that can be integrated with the PSA unit (1) for enhancing the life of a PSA adsorber bed. The present invention also provides a process for in-situ regenerating a PSA adsorber bed through the modular portable regeneration system.

Description

[0001] A MODULAR PORTABLE REGENERATION SYSTEM FOR PSA ADSORBER AND IN-SITU REGENERATION PROCESS OF PSA ADSORBER

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a modular portable regeneration system for a pressure swing adsorption (PSA) adsorber bed. Specifically, the present invention provides a modular hot nitrogen based regeneration system that can be integrated with the PSA unit for enhancing the life of a PSA adsorber bed. The present invention also provides a process for in-situ regenerating a PSA adsorber bed through the modular portable regeneration system.

[0004] BACKGROUND OF THE INVENTION

[0005] The use of the Pressure Swing Adsorption (PSA) process has seen tremendous growth during the last decades mainly due to its simplicity and low operating costs. Major applications have been the recovery of high purity hydrogen, methane and carbon dioxide as well as the generation of nitrogen and oxygen. In addition, it has gained significance for the bulk removal of carbon dioxide from direct reduction top-gases.

[0006] The PSA technology is based on a physical binding of gas molecules to adsorbent material. The respective force acting between the gas molecules and the adsorbent material depends on the gas component, type of adsorbent material, partial pressure of the gas component and operating temperature. The separation effect is based on differences in binding forces to the adsorbent material. Highly volatile components with low polarity, such as hydrogen, are practically non-adsorbable as opposed to molecules as N2, CO, CO2, hydrocarbons and water vapour. Consequently, these impurities can be adsorbed from a hydrogen containing stream and high purity hydrogen is recovered.

[0007] The PSA process works at basically constant temperature and uses the effect of alternating pressure and partial pressure to perform adsorption and desorption. Since heating or cooling is not required, short cycles within the range of minutes are achieved. The PSA process consequently allows the economical removal of large amounts of impurities.

[0008] Adsorption is carried out at high pressure (and hence high respective partial pressure) until the equilibrium loading is reached. At this point in time, no further adsorption capacity is available, and the adsorbent material must be regenerated. This regeneration is done by lowering the pressure to slightly above atmospheric pressure resulting in a respective decrease in equilibrium loading. As a result, the impurities on the adsorbent material are desorbed and the adsorbent material is regenerated. The amount of impurities removed from a gas stream within one cycle corresponds to the difference of adsorption to desorption loading. After termination of regeneration, pressure is increased back to adsorption pressure level and the process starts again from the beginning. Some of the prior art disclosing the method of adsorbent regeneration have been given below.

[0009] US7300498B2 discloses a system and method for removal of solvents, or other materials, from an exhaust stream, uses an active adsorption bed and a bed that is periodically regenerated. Electrically heated nitrogen may be used to regenerate the beds. A portion of the exhaust stream to be cleaned is diverted to a heat exchanger, so as to pre-heat the nitrogen used for regeneration. Liquid nitrogen, preferably from the same source as that used to provide gas for regeneration, is directed to the active bed, lowering its temperature and increasing its efficiency.

[0010] US5863852A discloses a method for regenerating a nickel-based catalytic adsorbent without using hydrogen in each cycle. Depending upon the configuration of the adsorbent bed, one or more interim regenerations, comprising the steps of heating the bed, flowing ultra-high purity nitrogen without hydrogen through the bed to remove adsorbed species, followed by cooling the bed, can be used to prepare the adsorbent bed for removal of unwanted species contained in cryogenically produced nitrogen in order to make ultra-high purity (UHP) nitrogen.

[0011] CN1611295A discloses a regeneration method of alumina wax adsorbing agent. Its main process includes the following steps: using solvent to wash the alumina adsorbing agent whose adsorption activity is lost for 5-10 times, then making constant temperature at 80 degree C-200 degree C for 30 min - 5 hours under the condition of nitrogen gas atmosphere and making constant temperature at 250 degC-400 degree C for 1-5 hours.

[0012] H2 PSA units are extensively used in refineries for H2 purification from Steam Methane Reformer (SMR) off gases and Continuous catalyst regeneration (CCR) off gases. These PSA units are generally designed with adsorbent life of up to 8 years. Ideally, PSA adsorbents can have an infinite life-time if the unit is operated at ideal conditions. However, in many cases, due to undesirable trace impurities in the feed, the adsorbents performance starts deteriorating before the guaranteed life. In such cases, adsorbents should be replaced with fresh adsorbents every time. Assuming aplant life of 30 years, at least 5-6 adsorbent replacements will be carried out. Instead, the adsorbents can be regenerated to increase the adsorbent life. But the regeneration methods available in the prior art mostly use solvents for regeneration, are multi- step and provide single layer adsorption. Also, the system as known in the prior art needs to be shut down for replacement of the adsorbent beds and are not continuous. To overcome the drawbacks of the prior art, the need arises for the development of regeneration systems and methods using gas for regeneration as gas can be easily purified and reused. Also, the developed regeneration method should work for multi-layer adsorption and in a continuous mode without requiring a shutdown.

[0013] SUMMARY OF THE INVENTION

[0014] In an aspect, the present invention provides a modular portable regeneration system for enhancing the life of a PSA adsorber bed. The system comprises a hot nitrogen generation part and a pure nitrogen gas regeneration part. The hot nitrogen generation part adapted to provide a hot nitrogen gas flow stream to a PSA unit (1), wherein the hot nitrogen gas flow regenerates the PSA adsorber bed present in the PSA unit (1). The pure nitrogen gas regeneration part adapted to receive an impure nitrogen gas from the PSA unit (1), wherein the hot nitrogen generation part works in conjugation with the pure nitrogen regeneration part. The modular portable regeneration system is integrated with the PSA unit (1).

[0015] In an embodiment of the present invention, there is provided a system, wherein the hot nitrogen generation part comprises a blower (5), a make-up gas control (7) and a heater (8,9).

[0016] In an embodiment of the present invention, there is provided a system, wherein the pure nitrogen generation part comprises a cooler (2), a knock down drum (KOD) (3) and a bleed control (4).

[0017] In an embodiment of the present invention, there is provided a system, wherein the cooler (2) cools down the impure nitrogen gas from the PSA adsorber bed by 15 °C to 45 °C to obtain cool impure nitrogen gas.

[0018] In an embodiment of the present invention, there is provided a system, wherein the knockout drum KOD (3) removes the liquid from the cool impure nitrogen gas into the drain. In an embodiment of the present invention, there is provided a system, wherein the bleed control (4) is operated to manage the nitrogen bleed gas, wherein the impurities are released through nitrogen bleed gas to obtain a pure nitrogen gas.

[0019] In an embodiment of the present invention, there is provided a system, wherein an impurity analyser is integrated with the bleed control (4) to detect the impurities in the nitrogen gas coming out of the knockout drum KOD (3),

[0020] In an embodiment of the present invention, there is provided a system, wherein the blower (5) is configured to maintain sufficient pressure of the pure nitrogen gas generated from the pure nitrogen generation part.

[0021] In an embodiment of the present invention, there is provided a system, wherein the blower (5) is connected to an optional adsorption based polishing unit (6) for removing any trace of impurities in the nitrogen gas flowing out of the blower (5).

[0022] In an embodiment of the present invention, there is provided a system, wherein the make-up gas control (7) is operated to manage the make-up nitrogen flow to maintain overall nitrogen gas flow in the system, wherein the make-up nitrogen is added to the nitrogen gas flowing out from the blower (5).

[0023] In an embodiment of the present invention, there is provided a system, wherein the heater (8,9) is configured to increase the temperature of the nitrogen gas by 220 °C to 280 °C before entering into the PSA unit (1), wherein the nitrogen gas entering the heater (8,9) is the nitrogen gas flowing out from the blower (5) after making up with nitrogen.

[0024] In an embodiment of the present invention, there is provided a system, wherein the PSA unit (1) comprises a plurality of PSA adsorber beds and the PSA unit (1) operates in a reduced bed mode, wherein one PSA adsorber bed is regenerated without shutting down the other PSA adsorber beds of the PSA unit (1).

[0025] In an embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed has a total loaded adsorbent quantity in a range of 14000 to 16000 kg. In an embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed has an average specific heat capacity (Cp) in a range of 900 to 1100 J kg'1K'1.

[0026] In an embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed is made of a carbon steel (CS) material having a thermal conductivity in a range of45 to 47 W m-1K1.

[0027] In an embodiment of the present invention, there is provided a system, wherein the hot nitrogen gas flow stream has a specific heat capacity (Cp) in a range of 900 to 1200 J kg'1K'1.

[0028] In another aspect, the present invention provides a process for in-situ regenerating a PSA adsorber bed through the modular portable regeneration system. The process includes steps of generating hot nitrogen gas stream in the hot nitrogen generation part of the modular portable regeneration system, through a heater (8,9) with outlet maintained at temperature in a range of 220 °C to 280 °C to generate the hot nitrogen gas flow stream. The next step includes circulating the hot nitrogen gas flow stream at a flow rate in a range of 1000 to 3000 Nm3 / h through at least one PSA adsorber bed present in the PSA unit (1) for a period of time in a range of 8 to 24 hours, wherein the hot nitrogen gas flow stream removes impurities from the PSA adsorber bed to obtain a regenerated PSA adsorber bed.

[0029] The next step includes transferring the impure nitrogen gas from the PSA adsorber bed of the PSA unit (1) into a cooler (2) present in the pure nitrogen regeneration part of the modular portable regeneration system, wherein an outlet temperature of the cooler (2) is maintained in a range of 15 °C to 45 °C to obtain a cool impure nitrogen gas. The next step includes passing the cool impure nitrogen gas through a knockout drum KOD (3) to remove the liquid from the cool impure nitrogen gas into the drain and to remove the impurities from the cool impure nitrogen gas through the nitrogen bleed gas to avoid build-up of impurities in nitrogen gas, recirculating through the hot nitrogen generation part of the modular portable regeneration system, wherein the flow rate of the hot nitrogen gas stream is maintained through a makeup nitrogen gas stream.

[0030] In an embodiment of the present invention, there is provided a process, wherein the PSA unit (1) comprises a plurality of PSA adsorber beds, wherein each adsorber has total loaded adsorbent quantity of 14000 to 16000 kg with average specific heat capacity Cp of 900 to 1100 J kg'1K1, wherein each PSA adsorber bed is made of a carbon steel (CS) material having a thermal conductivity in a range of 45 to 47 W m'1K1.

[0031] In an embodiment of the present invention, there is provided a process, wherein the hot nitrogen gas flow stream has a specific heat capacity (Cp) of 900 to 1200 J kg'1K'1, wherein the hot nitrogen gas flow stream is circulated at a flow rate of 1000 to 3000 Nm3 / h.

[0032] In an embodiment of the present invention, there is provided a process, wherein the makeup nitrogen gas stream is attached to the hot nitrogen generation part and the bleeding out nitrogen gas stream is attached to the pure nitrogen regeneration part of the modular portable regeneration system, wherein the makeup nitrogen gas stream and the bleeding out nitrogen gas stream flow rate is up to 200 Nm3 / h, wherein circulating the hot nitrogen gas flow stream is bled by 5 to 10%.

[0033] BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0034] The following figures form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the figures in combination with the detailed description of the specific embodiments presented herein.

[0035] Figure 1 illustrates a modular portable regeneration system along with a PSA unit.

[0036] Figure 2 illustrates the modular portable regeneration system having a hot nitrogen generation part and a pure nitrogen gas regeneration part.

[0037] Figure 3 illustrates the isotherm plot of CH4 on HP -AC-147 at RT.

[0038] Figure 4 illustrates isotherm plot of CO2 on activated carbon at 25 °C (RT).

[0039] DETAILED DESCRIPTION OF THE INVENTION

[0040] For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are delineated here. These definitions should be read in light of the remainder of the disclosure and understood as by a person of skill in the art.

[0041] The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below. The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”. The term "at least one" is used to mean one or more and thus includes individual components as well as mixtures / combinations.

[0042] Throughout this specification, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps. The term “including” is used to mean “including but not limited to”, “including” and “including but not limited to” are used interchangeably.

[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods and materials are now described.

[0044] The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally equivalent products, compositions, and methods are clearly within the scope of the disclosure, as described herein.

[0045] In an aspect, the present invention provides a modular portable regeneration system for enhancing life of a PSA adsorber bed. The system comprises a hot nitrogen generation part adapted to provide a hot nitrogen gas flow stream to a PSA unit (1), wherein the hot nitrogen gas flow regenerates the PSA adsorber bed present in the PSA unit (1). A pure nitrogen gas regeneration part adapted to receive an impure nitrogen gas from the PSA unit (1), wherein the hot nitrogen generation part works in conjugation with the pure nitrogen regeneration part. The modular portable regeneration system is integrated with the PSA unit (1).

[0046] In an embodiment of the present invention, there is provided a system, wherein the hot nitrogen generation part comprises a blower (5), a make-up gas control (7) and a heater (8,9). In an embodiment of the present invention, there is provided a system, wherein the pure nitrogen generation part comprises a cooler (2), a knock down drum (KOD) (3) and a bleed control (4).

[0047] In an embodiment of the present invention, there is provided a system, wherein the cooler (2) cools down the impure nitrogen gas from the PSA adsorber bed by 15 °C to 45 °C to obtain cool impure nitrogen gas.

[0048] In an embodiment of the present invention, there is provided a system, wherein the knockout drum KOD (3) removes the liquid from the cool impure nitrogen gas into the drain.

[0049] In an embodiment of the present invention, there is provided a system, wherein the bleed control (4) is operated to manage the nitrogen bleed gas, wherein the impurities are released through nitrogen bleed gas to obtain a pure nitrogen gas.

[0050] In an embodiment of the present invention, there is provided a system, wherein an impurity analyser is integrated with the bleed control (4) to detect the impurities in the nitrogen gas coming out of the knockout drum KOD (3),

[0051] In an embodiment of the present invention, there is provided a system, wherein the blower (5) is configured to maintain sufficient pressure of the pure nitrogen gas generated from the pure nitrogen generation part.

[0052] In an embodiment of the present invention, there is provided a system, wherein the blower (5) is connected to an optional adsorption based polishing unit (6) for removing any trace of impurities in the nitrogen gas flowing out of the blower (5).

[0053] In an embodiment of the present invention, there is provided a system, wherein the make-up gas control (7) is operated to manage the make-up nitrogen flow to maintain overall nitrogen gas flow in the system, wherein the make-up nitrogen is added to the nitrogen gas flowing out from the blower (5).

[0054] In an embodiment of the present invention, there is provided a system, wherein the heater (8,9) is configured to increase the temperature of the nitrogen gas by 220 °C to 280 °C before entering into the PSA unit (1), wherein the nitrogen gas entering the heater (8,9) is the nitrogen gas flowing out from the blower (5) after making up with nitrogen.

[0055] In an embodiment of the present invention, there is provided a system, wherein the PSA unit (1) comprises a plurality of PSA adsorber beds and the PSA unit (1) operates in a reduced bed mode, wherein one PSA adsorber bed is regenerated without shutting down the other PSA adsorber beds of the PSA unit (1).

[0056] In an embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed has a total loaded adsorbent quantity in a range of 14000 to 35000 kg.

[0057] In another embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed has a total loaded adsorbent quantity in a range of 14000 to 30000 kg.

[0058] In another embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed has a total loaded adsorbent quantity in a range of 14000 to 16000 kg.

[0059] In a preferred embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed has a total loaded adsorbent quantity of 15000 kg.

[0060] In an embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed has an average specific heat capacity (Cp) in a range of 900 to 1100 J kg'1K'1.

[0061] In a preferred embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed has an average specific heat capacity (Cp) of 1000 J kg'1K'1.

[0062] In an embodiment of the present invention, there is provided a system, wherein each PSA adsorber bed is made of a carbon steel (CS) material having a thermal conductivity in a range ofdS to dT W m'1K'1.

[0063] In an embodiment of the present invention, there is provided a system, wherein the hot nitrogen gas flow stream has a specific heat capacity (Cp) in a range of 900 to 1200 J kg'1K'1. In a preferred embodiment of the present invention, there is provided a system, wherein the hot nitrogen gas flow stream has a specific heat capacity (Cp) of 1014 J kg'1K1.

[0064] In an embodiment of the present invention, there is provided a process, wherein the hot nitrogen gas flow stream is circulated at a flow rate of 100 to 4000 Nm3 / h.

[0065] In another aspect, the present invention also provides a process for in-situ regenerating a PSA adsorber bed through the modular portable regeneration system. The process includes steps of generating hot nitrogen gas stream in the hot nitrogen generation part of the modular portable regeneration system, through a heater (8,9) with outlet maintained at temperature in a range of 220 °C to 280 °C to generate the hot nitrogen gas flow stream. The next step includes circulating the hot nitrogen gas flow stream at a flow rate in a range of 1000 to 3000 Nm3 / h through at least one PSA adsorber bed present in the PSA unit (1) for a period of time in a range of 8 to 24 hours, wherein the hot nitrogen gas flow stream removes impurities from the PSA adsorber bed to obtain a regenerated PSA adsorber bed.

[0066] The next step includes transferring the impure nitrogen gas from the PSA adsorber bed of the PSA unit (1) into a cooler (2) present in the pure nitrogen regeneration part of the modular portable regeneration system, wherein an outlet temperature of the cooler (2) is maintained in a range of 15 °C to 45 °C to obtain a cool impure nitrogen gas. The next step includes passing the cool impure nitrogen gas through a knockout drum KOD (3) to remove the liquid from the cool impure nitrogen gas into the drain and to remove the impurities from the cool impure nitrogen gas through the nitrogen bleed gas to avoid build-up of impurities in nitrogen gas recirculating through the hot nitrogen generation part of the modular portable regeneration system, wherein the flow rate of the hot nitrogen gas stream is maintained through a makeup nitrogen gas stream.

[0067] In an embodiment of the present invention, there is provided a process, wherein the PSA unit (1) comprises a plurality of PSA adsorber beds, wherein each adsorber has total loaded adsorbent quantity of 14000 to 16000 kg with average specific heat capacity Cp of 900 to 1100 J kg'1K'1, wherein each PSA adsorber bed is made of a carbon steel (CS) material having a thermal conductivity in a range of 45 to 47 W m'1K'1. In an embodiment of the present invention, there is provided a process, wherein the hot nitrogen gas flow stream has a specific heat capacity (Cp) of 900 to 1200 J kg'1K'1, wherein the hot nitrogen gas flow stream is circulated at a flow rate of 1000 to 3000 Nm3 / h.

[0068] In an embodiment of the present invention, there is provided a process, wherein the makeup nitrogen gas stream is attached to the hot nitrogen generation part and the bleeding out nitrogen gas stream is attached to the pure nitrogen regeneration part of the modular portable regeneration system, wherein the makeup nitrogen gas stream and the bleeding out nitrogen gas stream flow rate is up to 200 Nm3 / h, wherein circulating the hot nitrogen gas flow stream is bled by 5 to 10%.

[0069] In an embodiment of the present invention, there is provided a process, wherein the PSA adsorber bed is made of a Stainless Steel (SS) material based on the feed impurities.

[0070] In a preferred embodiment, there is provided a process, wherein the hot nitrogen gas flow stream is circulated at a flow rate of 2000 Nm3 / h.

[0071] During regeneration, the cooler inlet temperature will slowly increase from atmospheric temperature and reaches maximum and holds as the regeneration approaches completion.

[0072] In an embodiment of the present invention, there is provided a process, wherein the inlet temperature of the cooler varies from sub-atmospheric temperature to 240 °C.

[0073] In another embodiment of the present invention, there is provided a process, wherein the inlet temperature of the cooler varies from sub-atmospheric temperature to 220 °C.

[0074] The adsorbents can be regenerated in-situ using hot nitrogen at atmospheric or under vacuum conditions.

[0075] By regenerating the adsorbents at temperature above 200 °C, complete capacity of the adsorbents can be reversed.

[0076] The PSA system with integrated hot nitrogen regeneration unit is more suitable in continuous catalyst reformer (CCR) PSA, refinery off-gases (ROG) PSA, etc. where the possibility of heavy hydrocarbon ingress is high. Generally, these hydrocarbons tend to deactivate the adsorbents resulting in unit capacity reduction.

[0077] EXAMPLES:

[0078] The disclosure will now be illustrated with working examples, which are intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure.

[0079] Example 1: Adsorbent regeneration system.

[0080] PSA unit with 6 adsorbers that can be operated in 6 bed and 5 bed mode. Each adsorber has total loaded adsorbent quantity of 15000 kg with average Cp of 1000 J kg'1K'1. Adsorber vessel made of CS material with thermal conductivity of 45-47 W m'1K1. N2 gas used for regeneration which has Cp of 1014 J kg'1K'1(figures 1 and 2).

[0081] Requirements:

[0082] ■ Circulating hot regeneration N2 gas of 2000 Nm3 / h.

[0083] ■ 5-10% of circulating will be bled to avoid buildup of undesired components in the N2 gas.

[0084] ■ Make-up & bleed gas flow rate of up to 200 Nm3 / h.

[0085] ■ Regeneration to be carried out at temperatures > 220 °C.

[0086] ■ Cooler inlet temperature will vary from sub-atmospheric temperature to inlet hot N2 temperature.

[0087] ■ Cooler outlet temperature at 40 °C.

[0088] ■ Heater outlet temperature > 240 °C. Heater power requirement is 220 kW.

[0089] Example 2: Studies on spent adsorbents from a Hydrogen generation unit (HGU) PSA.

[0090] Spent adsorbents from different levels of adsorber vessel were collected. Their capacities for adsorbing different adsorbates were measured. These adsorbents were then regenerated at high temperature and at vacuum. The capacities of these regenerated adsorbents were measured again. Spent adsorbents were regenerated at high temperature under hot nitrogen flow. The capacities of these regenerated adsorbents were measured again (figures 3 and 4).

[0091] The regenerated adsorbents were having >90% of the original capacity. Based on these findings, a compact system is designed for implementation.

Claims

CLAIMS:

1. A modular portable regeneration system for enhancing life of a PSA adsorber bed, wherein the system comprises: a hot nitrogen generation part adapted to provide a hot nitrogen gas flow stream to a PSA unit (1), wherein the hot nitrogen gas flow regenerates the PSA adsorber bed present in the PSA unit (1); and a pure nitrogen gas regeneration part adapted to receive an impure nitrogen gas from the PSA unit (1), wherein the hot nitrogen generation part works in conjugation with the pure nitrogen regeneration part, and the modular portable regeneration system is integrated with the PSA unit (1).

2. The system as claimed in claim 1, wherein the hot nitrogen generation part comprises a blower (5), a make-up gas control (7) and a heater (8,9).

3. The system as claimed in claim 1, wherein the pure nitrogen generation part comprises a cooler (2), a knock down drum (KOD) (3) and a bleed control (4).

4. The system as claimed in claim 3, wherein the cooler (2) cools down the impure nitrogen gas from the PSA adsorber bed by 15 °C to 45 °C to obtain cool impure nitrogen gas.

5. The system as claimed in claim 3, wherein the knockout drum KOD (3) removes the liquid from the cool impure nitrogen gas into the drain.

6. The system as claimed in claim 3, wherein the bleed control (4) is operated to manage the nitrogen bleed gas, wherein the impurities are released through nitrogen bleed gas to obtain a pure nitrogen gas.

7. The system as claimed in claim 6, wherein an impurity analyser is integrated with the bleed control (4) to detect the impurities in the nitrogen gas coming out of the knockout drum KOD (3).

8. The system as claimed in claim 2, wherein the blower (5) is configured to maintain sufficient pressure of the pure nitrogen gas generated from the pure nitrogen generation part.

9. The system as claimed in claim 8, wherein the blower (5) is connected to an optional adsorption based polishing unit (6) for removing any trace of impurities in the nitrogen gas flowing out of the blower (5).

10. The system as claimed in claim 2, wherein the make-up gas control (7) is operated to manage the make-up nitrogen flow to maintain overall nitrogen gas flow in the system, wherein the make-up nitrogen is added to the nitrogen gas flowing out from the blower (5).

11. The system as claimed in claim 2, wherein the heater (8,9) is configured to increase the temperature of the nitrogen gas by 220 °C to 280 °C before entering into the PSA unit (1), wherein the nitrogen gas entering the heater (8,9) is the nitrogen gas flowing out from the blower (5) after making up with nitrogen.

12. The system as claimed in claim 1, wherein the PSA unit comprises a plurality of PSA adsorber beds and the PSA unit (1) operates in a reduced bed mode, wherein one PSA adsorber bed is regenerated without shutting down the other PSA adsorber beds of the PSA unit (1).

13. The system as claimed in claim 12, wherein each PSA adsorber bed has a total loaded adsorbent quantity in a range of 14000 to 16000 kg, wherein each PSA adsorber bed has an average specific heat capacity (Cp) in a range of 900 to 1100 J kg'1K'1.

14. The system as claimed in claim 12, wherein each PSA adsorber bed is made of a carbon steel (CS) material having a thermal conductivity in a range of 45 to 47 W m'1K'1, wherein the hot nitrogen gas flow stream has a specific heat capacity (Cp) in a range of 900 to 1200 J kg'1K1.

15. A process for in- situ regenerating a PSA adsorber bed through the modular portable regeneration system as claimed in claim 1, wherein the process comprises steps of:generating hot nitrogen gas stream in the hot nitrogen generation part of the modular portable regeneration system, through a heater (8,9) with outlet maintained at temperature in a range of 220 to 280 °C to generate the hot nitrogen gas flow stream; circulating the hot nitrogen gas flow stream at a flow rate in a range of 1000 to 3000 Nm3 / h through at least one PSA adsorber bed present in the PSA unit (1) for a period of time in a range of 8 to 24 hours, wherein the hot nitrogen gas flow stream removes impurities from the PSA adsorber bed to obtain a regenerated PSA adsorber bed; transferring the impure nitrogen gas from the PSA adsorber bed of the PSA unit (1) into a cooler (2) present in the pure nitrogen regeneration part of the modular portable regeneration system, wherein an outlet temperature of the cooler (2) is maintained in a range of 15 °C to 45 °C to obtain a cool impure nitrogen gas; and passing the cool impure nitrogen gas through a knockout drum KOD (3) to remove the liquid from the cool impure nitrogen gas into the drain and to remove the impurities from the cool impure nitrogen gas through the nitrogen bleed gas to avoid build-up of impurities in nitrogen gas, recirculating through the hot nitrogen generation part of the modular portable regeneration system, wherein the flow rate of the hot nitrogen gas stream is maintained through a make-up nitrogen gas stream.

16. The process as claimed in claim 15, wherein the PSA unit comprises a plurality of PSA adsorber beds, wherein each adsorber has total loaded adsorbent quantity of 14000 to 16000 kg with average specific heat capacity Cp of 900 to 1100 J kg'1K1, wherein each PSA adsorber bed is made of a carbon steel (CS) material having a thermal conductivity in a range of 45 to 47 W m'1K1.

17. The process as claimed in claims 15, wherein the hot nitrogen gas flow stream has a specific heat capacity (Cp) of 900 to 1200 J kg'1K'1, wherein the hot nitrogen gas flow stream is circulated at a flow rate of 1000 to 3000 Nm3 / h.

18. The process as claimed in claims 15, wherein the makeup nitrogen gas stream is attached to the hot nitrogen generation part and the bleeding out nitrogen gas stream is attached to the pure nitrogen regeneration part of the modular portable regeneration system, wherein the makeup nitrogen gas stream and the bleeding out nitrogen gas stream flow rate is up to 200 Nm3 / h, wherein circulating the hot nitrogen gas flow stream is bled by 5 to 10%.

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