Description:FIELD OF THE INVENTION:

The present invention relates to a process and a reactor for CO removal from impure hydrogen. Specifically, the present invention relates to a single step electrochemical process and a single chamber electrochemical reactor for CO removal from impure hydrogen. The single step electrochemical process and the single chamber electrochemical reactor are useful in fuel cells to provide a continuous stream of pure hydrogen.

BACKGROUND OF THE INVENTION:

Hydrogen is a clean fuel and is used in a Polymer Electrolyte Membrane (PEM) fuel cell to produce electrochemical energy and only water in exhaust. Further, hydrogen is produced through Thermochemical pathways which typically involve steam methane reforming, and such Thermochemical pathway is a high-temperature process in which steam reacts with a hydrocarbon fuel to produce grey/blue hydrogen depending on CO2 captured. Today, about 95% of all grey hydrogen is produced from steam reforming of natural gas. Hydrogen produced from steam reforming process comes alongwith other inherent impurities like CO, CH4 and CO2 in the ppm level (10-500 ppm).

The CO present in the hydrogen stream comes in contact with catalyst on the anode of fuel cell. It further diffuses over the surfaces of the Pt catalyst and deactivates the active surfaces of Pt thereby reducing the hydrogen oxidation. As a result, the performance of fuel cell stack deteriorates over the period of time. Many processes have been proposed to remove CO externally before entering fuel cell environments including Pressure Swing Adsorption (PSA), membrane separation, CO-water gas shift reaction (CO-WGS), Preferential oxidation (PrOX) etc. However, all of these processes are either cost/energy-intensive, need additional infrastructure, utilities and result in significant hydrogen yield loss, thereby making the purification process very complex and increase the overall cost of the fuel cell.

Impure hydrogen produced from grey process and supply on the anode side of PEM fuel cell is distributed across the catalyst surface through Gas Diffusing Layer (GDL). The reaction occurring on anode catalyst layers is referred to as Hydrogen Oxidation Reaction (HOR), represented as:

H2+2Cat* ?2Cat+2H++2e-
(1)

However, the presence of CO degrades the performance of fuel cell by binding to available active sites which can be represented as:
CO+Cat ? Cat-CO (2)
Thus, CO affects the anode overpotential thereby limiting the current output from the fuel cell. On continuous operation of a fuel cell system with CO contaminated hydrogen, all the active sites are eventually blocked by CO and the output voltage of fuel cell reduces exponentially at a given load current. As the anode overpotential increases (reduction in overall output voltage) to CO oxidation potential, adsorbed CO molecules on the catalyst sites are electrochemically oxidized.

Further, the following prior art documents disclose various processes of CO removal.

U.S. Pat. No. 6,245,214 B1 discloses CO oxidation by electrochemical or galvanic pathway by passing humidified reformate hydrogen stream in the anode and air/oxygen in the cathode of the cell. CO is oxidized by passing current or applying a potential difference between two terminals essentially due to formation of oxidation species from the adsorbed water molecule. However, the claimed process is incapable of supplying continuous hydrogen downstream during CO oxidation. Also, due to electrochemical oxidation of hydrogen in the CO removal unit, net fuel efficiency for a fuel cell is reduced. The patent also doesn’t describe any process to utilize the hydrogen generated during CO oxidation.

U.S. Pat. No. US6830675B2 discloses a process for removing carbon monoxide from a gas stream, in which the gas stream loaded with CO is guided through a device, and the CO is removed from the gas stream through adsorption on the working electrode. As a function of an electrical voltage between the working electrode and the counter electrode, or between the working electrode and the reference electrode, an electrode cleaning mode is enabled by triggering a current flow between the working electrode and the counter electrode, and the CO adsorbed on the working electrode is oxidized to CO2.

U.S. Pat. Application No. US20020071977A1 discloses a fuel cell system includes a fuel cell having an electrode, and an electrochemical cell having a device. The electrochemical cell includes a cathode, an anode in fluid communication with the electrode of the fuel cell, and an electrolyte in electrical communication with the cathode and the anode. The device is in electrical communication with the anode of the electrochemical cell and adapted to vary the potential of the anode. The electrochemical cell and the device are capable of reducing an amount of carbon monoxide that enters the fuel cell system.

WO2007076596A1 A discloses a process and system for counteracting performance deterioration in an electrochemical fuel cell includes passive re-activation, active re-activation, or both. Active re-activation includes intermittently applying positive voltage electrical pulse across the anode. The positive voltage applied is less than that required for decomposition of water. Passive re-activation includes interposing a resistive load between the anode and the cathode while fuel stream flow to the anode is interrupted. The resistive load increases voltage potential at the anode to less than that required for oxidation of carbon.

U.S. Pat. No. 8,715,868 B2 relates to twin electrochemical filters for CO removal from reformate hydrogen by voltage pulsing. The dual filters ensure a continuous supply of hydrogen to fuel cell. Reformate Hydrogen is passed on the anode side while 4% H2 in N2 is passed on the cathode side of electrochemical filters. However, due to proposed twin filter configuration, the area requirement of the device and cost increases substantially for maintaining continuous hydrogen supply downstream. Also, as 4% H2 in N2 is proposed to be used on the cathode side, hydrogen generated on the cathode side during CO oxidation cannot be used using this solution. Additionally, hydrogen oxidized along with CO during the regeneration stage cannot be used thus reducing the overall fuel efficiency.

The prior art documents also attempted electrochemical techniques for CO removal, but these processes are not yet commercialized due to technical limitations in terms of volume and mass of the device, batch scale operation, slippage of CO and durability of device.

Accordingly, there are problems in the state of the art with respect to CO removal from grey hydrogen in an easy and cost-effective manner. Hence, there is need for a process of CO removal from grey hydrogen in an easy and cost-effective manner.

Development of electrochemical process for CO removal from hydrogen stream, without loss of fuel cell performance and hydrogen throughput.

SUMMARY OF THE INVENTION:

The present disclosure provides a single step electrochemical process and a single chamber electrochemical reactor for CO removal from impure hydrogen. Specifically, the single step electrochemical process and the single chamber electrochemical reactor removes CO from a humidified hydrogen gas stream.

The single step electrochemical process includes first step of passing the humidified hydrogen gas stream through a first bed having a working electrode adapted to produce a treated gas stream, wherein, the working electrode performs a CO adsorption process, and a CO2 desorption process. Then passing the treated gas stream through a second bed having an electrolyte, wherein the electrolyte transfers the treated gas stream from the first bed to a third bed. Then passing the treated gas stream through the third bed having a reference electrode adapted to produce a CO free hydrogen gas stream, wherein, the first bed, the second bed, and the third bed are placed in a single chamber electrochemical reactor.

The working electrode is made up of a graphitized carbon layer, wherein the first side of the graphitized carbon layer is a porous layer to allow the impure hydrogen gas stream to flow in a flow direction and the second side of the graphitized carbon layer is a catalyst layer to perform the CO adsorption process.
When the catalyst layer of the working electrode completes the CO adsorption process, a pulse is applied between the working electrode and the reference electrode to perform the CO2 desorption process on the working electrode. The electrons move from the working electrode to the reference electrode through the circuit, and the treated gas stream passes through the electrolyte to the reference electrode, wherein, the reference electrode is adapted for hydrogen evolution.

Further the single chamber electrochemical reactor includes a first bed, a second bed, and a third bed all are placed in the single chamber electrochemical reactor, wherein, the second bed is placed between the first bed and the third bed. The working electrode and the reference electrode are connected through a circuit having a DC source. When the working electrode completes the CO adsorption process, a pulse is applied through the DC source to complete the CO2 desorption process.

Further, the first bed includes a working electrode, wherein the humidified hydrogen gas stream is passed through the working electrode to get a treated gas stream, wherein, the working electrode performs a CO adsorption process, and a CO2 desorption process.

The second bed includes an electrolyte, wherein the treated gas stream is passed through the electrolyte. The electrolyte is made of a porous paper with a relative humidity in a range of 10-100 % RH.

The third bed includes a reference electrode which performs a hydrogen evolution process, wherein, the treated gas stream is passed through the reference electrode to produce a CO free hydrogen gas stream.

OBJECTIVE OF THE INVENTION:

The primary objective of the present disclosure is to provide a process for CO removal and hydrogen evolution in one single chamber of electrochemical reactor without any loss of hydrogen throughput and the H2 recovery is 100%. (PSA H2 recovery 86-88% vs. HyPCRM H2 recovery 100%)

It is further objective of the present disclosure to provide a process for CO elimination up to 1 % from hydrogen produced from refinery or reformate gases for fuel cell application.

It is further objective of the present disclosure to provide a unique and compact design for both stationery and mobility applications.

It is further objective of the present disclosure is that the inventive process has Low catalyst loading compared to other technologies used for CO removal.

It is further objective of the present disclosure to utilize maximum surface area of catalyst for CO adsorption due to radial and axial flow streams in the electrochemical reactor.

It is further objective of the present disclosure to provide a process wherein the working electrode and reference/counter electrode both are in same chamber.

It is further objective of the present disclosure to provide a process which has the ability to operate at room temperature and atmosphere pressure.

It is further objective of the present disclosure to provide a process which eliminates the need for catalyst level modification for CO removal in a fuel cell.

It is further objective of the present disclosure to provide a process which provides constant power output from fuel cell thus additional external power source is obliterated.

It is further objective of the present disclosure to provide a process for CO removal in which Fuel cell performance and durability of its components is maintained without any degradation due to CO present in feed hydrogen.

It is further objective of the present disclosure to provide a process which has quick start-up and shut down times, thus reducing the response time of the system.

It is further objective of the present disclosure to provide a retrofitted solution to any new/existing fuel cell system exposed to CO contamination.

BRIEF DESCRIPTION OF THE DRAWING:

The detailed description below will be better understood when read in conjunction with the appended drawings. For the purpose of assisting in the explanation of the invention, there are shown in the drawings embodiments which are presently preferred and considered illustrative.
It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown therein.
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1: illustrates a schematic diagram of the single chamber electrochemical reactor;
Figure 2: illustrates arrangement of the first bed, the second bed, and the third bed of the single chamber electrochemical reactor; and
Figure 3: illustrates a graph representing the CO adsorption and oxidation test results.

DESCRIPTION OF THE INVENTION:

According to the main embodiment, the present disclosure provides a single step electrochemical process and a single chamber electrochemical reactor for CO removal from impure hydrogen. Specifically, the process and the reactor as disclosed combines the characteristics of physical adsorption and electrochemical intervention for CO removal.

The process as disclosed herein can remove CO concentration up to 1% from impure stream of grey hydrogen. The process as disclosed works on two principles i.e., CO adsorption over the surface of Pt catalyst through physical adsorption process and CO oxidation at catalyst surface through electrochemical process. These two processes are performed in one single electrochemical reactor to facilitate electrochemical reactions so that CO removal can proceed continuously from grey hydrogen feed without disturbing the fuel cell operations.

Specifically, the present disclosure provides a single step electrochemical process for CO removal from a humidified hydrogen gas stream. The process includes first step of passing the humidified hydrogen gas stream through a first bed having a working electrode adapted to produce a treated gas stream, wherein, the working electrode performs a CO adsorption process, and a CO2 desorption process. Then passing the treated gas stream through a second bed having an electrolyte, wherein the electrolyte transfers the treated gas stream from the first bed to a third bed. Then passing the treated gas stream through the third bed having a reference electrode adapted to produce a CO free hydrogen gas stream, wherein, the first bed, the second bed, and the third bed are placed in a single chamber electrochemical reactor.

The working electrode is made up of a graphitized carbon layer, wherein the first side of the graphitized carbon layer is a porous layer to allow the impure hydrogen gas stream to flow in a flow direction and the second side of the graphitized carbon layer is a catalyst layer to perform the CO adsorption process.

When the catalyst layer of the working electrode completes the CO adsorption process, a pulse is applied between the working electrode and the reference electrode to perform the CO2 desorption process on the working electrode. Wherein, the working electrode and the reference electrode are connected through a circuit having a DC source, and the pulse is applied through the DC source. The pulse is in a range of 0.3-1.0 V, the pulse performs oxidation of hydrogen (H2) and carbon monoxide (CO) to produce electrons and the treated gas stream comprising CO2, hydrogen, and protons.

The electrons move from the working electrode to the reference electrode through the circuit, and the treated gas stream passes through the electrolyte to the reference electrode, wherein, the reference electrode is adapted for hydrogen evolution.

The CO adsorption process, and the CO2 desorption process over the working electrode is carried out in a temperature range of 0-80o C, wherein, the temperature is of a feed temperature or a reactor temperature. The CO adsorption process, and the CO2 desorption process over the working electrode is carried out at a feed pressure in a range of 0-10 bar.

Specifically, the present disclosure provides a single chamber electrochemical reactor for CO removal from a humidified hydrogen gas stream. The electrochemical reactor includes a first bed, a second bed, and a third bed all are placed in the single chamber electrochemical reactor, wherein, the second bed is placed between the first bed and the third bed.

Further, the first bed includes a working electrode, wherein the humidified hydrogen gas stream is passed through the working electrode to get a treated gas stream, wherein, the working electrode performs a CO adsorption process, and a CO2 desorption process.

The working electrode comprises a graphitized carbon layer having a porosity in a range of 10-300% and a thickness of 10-20000 micrometer. The first side of the graphitized carbon layer is a porous layer to allow the humidified hydrogen gas stream to flow in a flow direction, wherein, the flow direction is a radial direction, or an axial direction.

The second side of the graphitized carbon layer is a catalyst layer to perform the CO adsorption process, and the CO2 desorption process. The catalyst layer comprises a CO adsorption metal coated over one side of the carbon layer, wherein the CO adsorption metal is selected from Platinum (Pt), Ruthenium (Ru) or a combination thereof.

The second bed includes an electrolyte, wherein the treated gas stream is passed through the electrolyte. The electrolyte is made of a porous paper with a relative humidity in a range of 10-100 % RH.

The third bed includes a reference electrode which performs a hydrogen evolution process, wherein, the treated gas stream is passed through the reference electrode to produce a CO free hydrogen gas stream. The reference electrode comprises a graphitized carbon layer having a porosity in a range of 10-300% and a thickness of 10-20000 micrometer. The first side of the graphitized carbon layer is a porous layer to allow the treated gas stream to flow in a flow direction, wherein, the flow direction is a radial direction, or an axial direction.

The second side of the graphitized carbon layer is a catalyst layer to perform the hydrogen evolution process. The catalyst layer includes a hydrogen evolution metal coated over one side of the carbon layer, wherein, the hydrogen evolution metal is Ruthenium (Ru).

The working electrode and the reference electrode are connected through a circuit having a DC source. When the working electrode completes the CO adsorption process, a pulse is applied through the DC source to complete the CO2 desorption process. The pulse is in a range of 0.3-1.0 V, the pulse performs oxidation of hydrogen (H2) and carbon monoxide (CO) to produce electrons and the treated gas stream comprising CO2, hydrogen, and protons.

Process Example:

The process as disclosed herein is generally referred to as HyPCRM (Hydrogen – Pulse based CO removal method). The said process is a pulse assisted CO removal process based on the execution of two simultaneous processes in one single electrochemical reactor to ensure continuous downstream supply of purified hydrogen. Wherein, the two simultaneous processes include a first process and a second process. The first process includes CO adsorption process, wherein CO as a contaminated gas present in a hydrogen gas stream is bonded over the catalyst layer of a working electrode through physical adsorption. The catalyst layer includes a CO adsorption metal selected from Platinum (Pt), Ruthenium (Ru) or a combination thereof.

The second process includes CO2 desorption process, wherein CO2 is removed by applying a pulse. Both these processes are conducted in a single chamber electrochemical reactor having a first bed (also referred to as bed-1), a second bed (also referred to as bed-2), and a third bed (also referred to as bed-3). Wherein, all three beds are placed in the single chamber electrochemical reactor, wherein, the second bed (bed-2) is placed between the first bed (bed-1) and the third bed (bed-3).

Wherein, the first bed (bed-1) includes a working electrode which is adapted to produce a treated gas stream from the humidified hydrogen gas stream, wherein, the working electrode performs a CO adsorption process, and a CO2 desorption process.

When the catalyst layer of the working electrode completes the CO adsorption process, a pulse is applied between the working electrode and the reference electrode to perform the CO2 desorption process on the working electrode wherein, the working electrode and the reference electrode are connected through a circuit having a DC source, and the pulse is applied through the DC source. The pulse is in a range of 0.3-1.0 V, the pulse performs oxidation of hydrogen (H2) and carbon monoxide (CO) to produce electrons and the treated gas stream comprising CO2, hydrogen, and protons.

The electrons move from the working electrode to the reference electrode through the circuit, and the treated gas stream passes through the electrolyte to the reference electrode, wherein, the reference electrode is adapted for hydrogen evolution. The hydrogen evolution is completed in third bed (bed-3) due to proton transfer through electrochemical process.

The figure 1 illustrates the schematic diagram of the single chamber electrochemical reactor, wherein, the impure humidified hydrogen gas stream (9) passes through the first bed having a working electrode (2) to produce a treated gas stream, which then passes through the second bed having an electrolyte (12) and then finally through the third bed having a reference electrode (7) to produce a CO free hydrogen gas stream (10). The CO free hydrogen gas stream (10) is then utilized in a PEM fuel cell (20). The working electrode (2) and the reference electrode (7) both are connected through a DC source (11).

Further figure 2 provides detailed arrangement of the first bed, the second bed, and the third bed of the single chamber electrochemical reactor and the same is explained hereinbelow.

Bed-1: The first bed includes a working electrode. The working electrode is made up of a graphitized carbon layer (2). The one side (1) of the graphitized carbon layer has open pore structure for inlet of humidified hydrogen stream and the other side (3) of the graphitized carbon layer contains Pt or PtRu catalyst coated surface for outlet of humidified hydrogen stream. The thickness of graphitized carbon layer (2) varies depending on resistance occurs due to electron flow in the flow direction and pressure drop across the Bed-1. The thickness of the graphitized carbon layer (2) is 200-1000 micrometer. Bed-1 acts as a working electrode for CO adsorption over surface of Pt catalyst and desorption of CO from the surface of Pt or PtRu catalyst.

Bed-2: Bed-2 includes the electrolyte which is made of porous paper so that gas can be permeated quickly, and the electrolyte is placed between bed-1 and bed-3. The electrolyte helps in transferring protons from bed-1 to bed-3. Further, the Bed-2 is enough humidified (< 100% RH) in order to reduce the resistances during the protons transfer.

Bed-3: The third bed includes a reference electrode. The reference electrode is made up of a graphitized carbon layer (7). The one side (6) of the graphitized carbon layer (7) contains Ru catalyst coated surface for inlet of humidified hydrogen stream and the other side (8) of the graphitized carbon layer (7) has open pore structure for output of hydrogen stream. Thickness of graphitized carbon layer (7) varies depending on resistance occurs due to electron flow in the flow direction and pressure drop across the Bed-3. The thickness of the graphitized carbon layer (7) is 200-1000 micrometer. Wherein, Bed-3 acts as reference/counter electrode for hydrogen evolution over the surface of Ru catalyst. As per density functional theory, Ru-C bonding is the most plausible active site for the hydrogen evolution of reaction (HER).

The complete reaction mechanism is explained hereinafter. The humidified hydrogen gas stream having humidity in the range of 10-100 % RH is passed through the carbon porous layer of the working electrode and diffused uniformly in the radial and axial flow directions. The humidified hydrogen gas stream alongwith contaminated gases continuously passed through the surface of catalyst layer of the working electrode until the open active side of Pt catalyst is available.

The reaction occurring on bed-1
CO+Cat (Pt)?Cat (Pt)-CO (1)

When 95-99 % of total sides of Pt surfaces of the catalyst layer of the working electrode are blocked due to CO poisoning, then a pulse is applied in the range of (0.3-1.0 V) between working electrode (Bed-1) and reference electrode (Bed-3). Due to the applied pulse CO adsorbed on the Pt surfaces of the catalyst layer of the working electrode is desorbed and/or removed in the form of CO2, and two reactions are explained hereinbelow.

Hydrogen Oxidation Reaction (HOR) due to open Pt sites available for hydrogen oxidation, represented as:
H2+2Cat (Pt)* ?2Cat (Pt)+2H++2e- (2)
Carbon monoxide Oxidation Reaction, represented as:
CO-Cat +Cat-H2O?2Cat+CO2+2H++2e-
During pulsing, the protons as generated tend to reach over the surface of the adjacent layer (4) of the electrolyte from the surface of catalyst layer of the working electrode and transfer to the next adjacent layer (5) of the electrolyte. The resistance generated due to protons transfer is highly dependent on thickness of electrolyte and water concentrations. And electrons produced in bed-1 during the CO and H2 oxidations can be transferred through external circuit to bed-3 for completing the hydrogen evolution reaction.

Hydrogen evolution is completed in bed-3 on one side (6) of the graphitized carbon layer (7), wherein the one side (6) contains Ru catalyst coated surface. The Hydrogen evolution is explained hereinbelow:
2H++2e-?H2 (4)
The HyPCRM (Hydrogen – Pulse based CO removal method) process as explained herein ensures a continuous supply of CO eliminated hydrogen stream for downstream applications, without any loss of hydrogen throughput and additionally utilizing hydrogen produced during CO oxidation is mixed with the pure hydrogen in a single reactor.

Figure 3 represents the CO adsorption and oxidation test results.

The current response in Figure 3 confirms the electrochemical oxidation of the CO molecule at a constant potential. Here, the electrodes are inactive in the presence of pure N2 gas flow for over 1000 seconds, but the same electrodes become involved in the electrochemical reaction once exposed to a CO atmosphere. A mixture of 5% CO and 95% N2 gas is supplied in a discontinuous manner to understand the CO oxidation process. The mixture gas is introduced after maintaining the electrode potential at 0.8V, which is indicated as *, and an immediate increase in current is noticed, indicating that CO molecules naturally adsorb on the active electrocatalyst, initiating CO oxidation. After a few seconds, the mixture gas flow is stopped, which is indicated as #, and the current production starts to decrease, indicating a reduction in CO concentration at the electrode surface. In figure 3, the current increment occurs from * to # duration due to CO mixture gas flow ON mode, and the current decrement occurs from # to * duration due to CO mixture gas flow OFF mode. The similar experiment is repeated at different intervals to confirm the electrodes' CO oxidation response.

The single step electrochemical process and a single chamber electrochemical reactor as disclosed have advantages such as the size of the CO mitigation chamber is drastically reduced to meet both onboard to onsite applications. Further, it is a continuous process and provides higher utilization of the catalyst surface area. Further, CO removal is carried out in one single reactor and the process, and the reactor removes the CO up to percentage level. No separate chamber is required for pure hydrogen as reference electrode continuously provides pure hydrogen, and this continuous process gives zero CO slippage during ex-situ operation, and also provides high durability.
, Claims:1. A single step electrochemical process for CO removal from a humidified hydrogen gas stream, wherein the process comprises:
passing the humidified hydrogen gas stream through a first bed having a working electrode adapted to produce a treated gas stream, wherein, the working electrode performs a CO adsorption process, and a CO2 desorption process;
passing the treated gas stream through a second bed having an electrolyte, wherein the electrolyte transfers the treated gas stream from the first bed to a third bed; and
passing the treated gas stream through the third bed having a reference electrode adapted to produce a CO free hydrogen gas stream, wherein, the first bed, the second bed, and the third bed are placed in a single chamber electrochemical reactor.

2. The process as claimed in claim 1, wherein, the working electrode comprises a graphitized carbon layer, wherein the first side of the graphitized carbon layer is a porous layer to allow the impure hydrogen gas stream to flow in a flow direction and the second side of the graphitized carbon layer is a catalyst layer to perform the CO adsorption process.

3. The process as claimed in claim 1, when the catalyst layer of the working electrode completes the CO adsorption process, a pulse is applied between the working electrode and the reference electrode to perform the CO2 desorption process on the working electrode wherein, the working electrode and the reference electrode are connected through a circuit having a DC source, and the pulse is applied through the DC source.

4. The process as claimed in claim 3, wherein, the pulse is in a range of 0.3-1.0 V, the pulse performs oxidation of hydrogen (H2) and carbon monoxide (CO) to produce electrons and the treated gas stream comprising CO2, hydrogen, and protons.

5. The process as claimed in claim 4, wherein, the electrons move from the working electrode to the reference electrode through the circuit, and the treated gas stream passes through the electrolyte to the reference electrode, wherein, the reference electrode is adapted for hydrogen evolution.

6. The process as claimed in claim 1, wherein, the CO adsorption process, and the CO2 desorption process over the working electrode is carried out in a temperature range of 0-80o C, wherein, the temperature is of a feed temperature or a reactor temperature.

7. The process as claimed in claim 1, wherein, the CO adsorption process, and the CO2 desorption process over the working electrode is carried out at a feed pressure in a range of 0-10 bar.

8. A single chamber electrochemical reactor for CO removal from a humidified hydrogen gas stream, wherein, the electrochemical reactor comprises:
a first bed having a working electrode, wherein the humidified hydrogen gas stream is passed through the working electrode to get a treated gas stream, wherein, the working electrode performs a CO adsorption process, and a CO2 desorption process;
a second bed having an electrolyte, wherein the treated gas stream is passed through the electrolyte; and
a third bed having a reference electrode which perform a hydrogen evolution process, wherein the treated gas stream is passed through the reference electrode to produce a CO free hydrogen gas stream, wherein, the first bed, the second bed, and the third bed are placed in a single chamber electrochemical reactor, the second bed is placed between the first bed and the third bed.

9. The single chamber electrochemical reactor as claimed in claim 8, wherein, the electrolyte is made of a porous paper with a relative humidity in a range of 10-100 % RH.

10. The single chamber electrochemical reactor as claimed in claim 8, wherein, the working electrode comprises a graphitized carbon layer having a porosity in a range of 10-300% and a thickness of 10-20000 micrometer.

11. The single chamber electrochemical reactor as claimed in claim 10, wherein, the first side of the graphitized carbon layer is a porous layer to allow the humidified hydrogen gas stream to flow in a flow direction and the second side of the graphitized carbon layer is a catalyst layer to perform the CO adsorption process, and the CO2 desorption process.

12. The single chamber electrochemical reactor as claimed in claim 11, wherein, the flow direction is a radial direction, or an axial direction.

13. The single chamber electrochemical reactor as claimed in claim 11, wherein, the catalyst layer comprises a CO adsorption metal coated over one side of the carbon layer, wherein the CO adsorption metal is selected from Platinum (Pt), Ruthenium (Ru) or a combination thereof.

14. The single chamber electrochemical reactor as claimed in claim 8, wherein, the reference electrode comprises a graphitized carbon layer having a porosity in a range of 10-300% and a thickness of 10-20000 micrometer.

15. The single chamber electrochemical reactor as claimed in claim 14, wherein, the first side of the graphitized carbon layer is a porous layer to allow the treated gas stream to flow in a flow direction and the second side of the graphitized carbon layer is a catalyst layer to perform the hydrogen evolution process.

16. The single chamber electrochemical reactor as claimed in claim 15, wherein, the flow direction is a radial direction, or an axial direction.

17. The single chamber electrochemical reactor as claimed in claim 15, wherein, the catalyst layer comprises a hydrogen evolution metal coated over one side of the carbon layer, wherein the hydrogen evolution metal is Ruthenium (Ru).

18. The single chamber electrochemical reactor as claimed in claim 8, wherein, the working electrode and the reference electrode are connected through a circuit having a DC source, when the working electrode completes the CO adsorption process, a pulse is applied through the DC source.

19. The single chamber electrochemical reactor as claimed in claim 8, wherein, the pulse is in a range of 0.3-1.0 V, the pulse performs oxidation of hydrogen (H2) and carbon monoxide (CO) to produce electrons and the treated gas stream comprising CO2, hydrogen, and protons.