HYDROGEN PRODUCTION SYSTEM

Abstract

A system and method for producing hydrogen gas. The system comprises at least one reformer reactor, at least one separator, at least one separator transport line, at least one regenerator reactor, at least one regenerator transport line and at least one recycling line. The reformer reactor is for containing a CO.sub.2 capturing sorbent A forming a used sorbent A*, wherein the reformer reactor is configured to allow reform of a feed material B and a steam C to produce a reformate gas mixture comprising H.sub.2 and CO.sub.2. The reformer reactor comprising a reformer inlet for feeding at least one of B and C into the reformer reactor and a reformer outlet for ejecting A* and H.sub.2. A separator configured to separate A* from H.sub.2. The separator comprising a separator inlet for feeding H.sub.2 and A* into the separator and a separator outlet for ejecting the separated A *. A separator transport line for transporting A* and H.sub.2 from the reformer outlet to the separator inlet. The regenerator reactor comprising a regenerator inlet for receiving at least a portion of A* separated in the separator. A regenerator power source configured to provide sufficient energy to the received A* for allowing release of CO.sub.2, thereby regenerating the sorbent. A regenerator outlet for ejecting the regenerated sorbent. A regenerator transport line for transporting the flow of A* from the separator outlet to the regenerator inlet. A recycling line arranged to transport at least a portion of the regenerated sorbent from the regenerator outlet into the reformer reactor. The regenerator transport line comprises a flow regulating device arranged to adjust the flow rate of A* being transported into the regenerator inlet.

Claims

1. A system for producing hydrogen gas, the system comprising: a reformer reactor (100) for containing a carbon dioxide capturing sorbent (A) forming a used sorbent (A*), wherein the reformer reactor (100) is configured to allow reform of a feed material (B) and a steam (C) to produce a reformate gas mixture comprising hydrogen gas (H.sub.2) and carbon dioxide (CO.sub.2), the reformer reactor (100) comprising a reformer inlet (130) for feeding at least one of the feed material (B) and the steam (C) into the reformer reactor (100) and a reformer outlet (155) for ejecting the used sorbent (A*) and the hydrogen gas (H.sub.2), a separator (300) configured to separate the used sorbent (A*) from the hydrogen gas (H.sub.2), the separator (300) comprising a separator inlet (304) for feeding the hydrogen gas (H.sub.2) and the used sorbent (A*) into the separator (300) and a separator outlet (305) for ejecting the separated used sorbent (A*), a separator transport line (150) for transporting the used sorbent (A*) and the hydrogen gas (H.sub.2) from the reformer outlet (155) to the separator inlet (304), a regenerator reactor (200) comprising a regenerator inlet (205) for receiving at least a portion of the used sorbent (A*) separated in the separator (300), a regenerator power source (220) configured to provide sufficient energy to the received used sorbent (A*) for allowing release of carbon dioxide (CO.sub.2), thereby regenerating the sorbent (A), and a regenerator outlet (215) for ejecting the regenerated sorbent (A), a regenerator transport line (320,430,430) for transporting the flow of the used sorbent (A*) from the separator outlet (305) to the regenerator inlet (205) and a recycling line (210) arranged to transport at least a portion of the regenerated sorbent (A) from the regenerator outlet (215) into the reformer reactor (100), characterized in that the regenerator transport line (320, 430) comprises a flow regulating device (440) arranged to adjust the flow rate (R.sub.A*) of the used sorbent (A*) being transported into the regenerator inlet (205).

2. The system according to claim 1, wherein the regenerator transport line (320,430) further comprises a tank (410) for containing the separated used sorbent (A*), a first regenerator transport line (320) coupled at one end to the separator outlet (305) and the other end to a tank inlet (405) of the tank (410) and a second regenerator transport line (430,430) coupled at one end to a tank outlet (415) of the tank (410) and the other end to the regenerator inlet (205). I

3. The system according to claim 1, wherein the flow regulating device (440) comprises a screw conveyor (450) arranged to rotate at an adjustable rotation speed (v.sub.r) to regulate the flow rate (R.sub.A*) of the used sorbent (A*) into the regenerator reactor (200).

4. The system according to claim 3, wherein the screw conveyor (450) is configured such that the used sorbent (A*) is transported into the regenerator reactor (200) at a higher flow rate (R.sub.A*,H) and a lower flow rate (R.sub.A*,L) when the screw conveyor (450) is rotating at a higher rotation speed (v.sub.r;H) and at a lower rotation speed (v.sub.r,L), respectively.

5. The system according to claim 3, wherein the flow regulating device (440) further comprises a motor (460) rotationally connected to the screw conveyor (450) and a variable speed drive (470) connected to the motor (460) to enable control of the rotation speed of the motor (460).

6. The system according to claim 1, wherein the system further comprises an automatic controller (500) in signal communication with the flow regulating device (440), the controller (500) being configured to automatically control operation of the flow regulating device (440) based on at least one of a flow rate of feed material (B) flowing into the reformer reactor (100), a flow rate of steam (C) flowing into the reformer reactor (100), a flow rate of a mixture of feed material (B) and steam (C) flowing into the reformer reactor (100), a flow rate of the used sorbent (A*) flowing between the reformer outlet (155) and the regenerator inlet (205), a flow rate of at least carbon dioxide (CO.sub.2) flowing between the reformer outlet (155) and the regenerator inlet (205), and a flow rate of the hydrogen gas (310), flowing out the separator (300).

7. The system according to claim 1, wherein the system further comprises an automatic controller (500) in signal communication with the flow regulating device (440), the controller (500) being configured to automatically control operation of the flow regulating device (440) based on at least one of composition ratios of feed material (B) relative to the total flow of steam (C) flowing into the reformer reactor (100), composition ratios of chemical compounds of fluid flowing between the reformer outlet (155) and the regenerator inlet (205), gas composition ratio between carbon monoxide (CO) and unconverted fuel gas flowing between the reformer outlet (155) and the regenerator inlet (205), gas composition ratio between carbon dioxide (CO.sub.2) and unconverted fuel gas flowing between the reformer outlet (155) and the regenerator inlet (205), and gas composition measurements in the hydrogen line (310).

8. The system according to claim 1, wherein the reformer reactor (100) includes an amount of the feed material (B), an amount of the steam ((') and an amount of the sorbent (A), wherein the feed material (B) comprises hydrocarbon containing fuel.

9. The system according to claim 1, wherein at least one of the reformer reactors (100) and the regenerator reactor (200) include a fluidized bed.

10. A method for producing hydrogen gas (H.sub.2) using the system according to claim 1, the method comprising the steps of: A. introducing the feed material (B) and the steam (C) into the reformer reactor (100) via the one or more reformer inlets (130), the reformer reactor (100) containing the sorbent (A) for capturing carbon dioxide (CO.sub.2), B. reforming the feed material (B) and the steam (C) within the reformer reactor (100) for producing the reformate gas mixture comprising the hydrogen gas (H.sub.2) and the carbon dioxide (CO.sub.2), wherein the sorbent (A) is capturing the carbon dioxide (CO.sub.2) to form the used sorbent (A*), C. transporting at least a portion of the used sorbent (A*) and at least the portion of the hydrogen gas (H.sub.2) from the reformer reactor (100) to the separator (300) through the separator transport line (150), D. separating the used sorbent (A*) from the hydrogen gas (H.sub.2) by operating the at least one separator (300), E. transporting at least a portion of the used sorbent (A*) from the separator (300) to the regenerator reactor (200) through the regenerator transport line (320,430,430) while adjusting the flow rate (R.sub.A*) of the used sorbent (A*) by operating the regulating device (440), F. providing energy to the used sorbent (A*) within the regenerator reactor (200) to release at least a portion of the carbon dioxide (CO.sub.2) from the used sorbent (A*), at least partly regenerating the sorbent (A) of step A, and G. recycling at least a portion of the regenerated sorbent (A) of step F by transporting the regenerated sorbent (A) from the regenerator reactor (200) to the reformer reactor (100) through the recycling line (210).

11. The method according to claim 10, wherein the flow regulating device (440) comprises a screw conveyor (450) and wherein the adjustment of the flow rate (R.sub.A*) in step E is achieved by adjusting the rotation speed (v.sub.r) of the screw conveyor (450).

12. The method according to claim 11, wherein adjusting the rotation speed (v.sub.r) of the screw conveyor (450) in step E further comprises adjusting the screw conveyor (450) to a higher rotation speed (v.sub.r,H) for transporting the used sorbent (A*) to the regenerator reactor (200) at a higher flow rate (R.sub.A*,H), and adjusting the screw conveyor to a lower rotation speed (v.sub.r,L) for transporting the used sorbent (A*) to the regenerator reactor (200) at a lower flow rate (R.sub.A*,L).

13. The method according to claim 10, wherein the flow regulating device (440) further comprises a motor (460) rotationally connected to the screw conveyor (450), and a variable speed drive (470) connected to the motor (460) to enable control of the rotation speed of the motor (440), and wherein the step of adjusting the rotation speed (v.sub.r) of the screw conveyor (450) in step E further comprises operating the variable speed drive (470) for changing the rotation speed of the motor (440).

14. The method according to claim 10, wherein the regenerator transport line (320,430,430) further comprises a tank (410) for containing the separated used sorbent (A*), a first regenerator transport line (320) coupled at one end to the separator outlet (305) and the other end to a tank inlet (405) of the tank (410) and a second regenerator transport line (430,430) coupled at one end to a tank outlet (415) of the tank (410) and the other end to the regenerator inlet (205), and wherein step E further includes filling the tank (410) to a predetermined minimum amount of the separated used sorbent (A*).

15. The system according to claim 4, wherein the flow regulating device (440) further comprises a motor (460) rotationally connected to the screw conveyor (450) and a variable speed drive (470) connected to the motor (460) to enable control of the rotation speed of the motor (460).

16. The system according to claim 5, wherein the system further comprises an automatic controller (500) in signal communication with the flow regulating device (440), the controller (500) being configured to automatically control operation of the flow regulating device (440) based on at least one of a flow rate of feed material (B) flowing into the reformer reactor (100), a flow rate of steam (C) flowing into the reformer reactor (100), a flow rate of a mixture of feed material (B) and steam (C) flowing into the reformer reactor (100), a flow rate of the used sorbent (A*) flowing between the reformer outlet (155) and the regenerator inlet (205), a flow rate of at least carbon dioxide (CO.sub.2) flowing between the reformer outlet (155) and the regenerator inlet (205), and a flow rate of the hydrogen gas (310), flowing out the separator (300).

17. The system according to claim 6, wherein the system further comprises an automatic controller (500) in signal communication with the flow regulating device (440), the controller (500) being configured to automatically control operation of the flow regulating device (440) based on at least one of composition ratios of feed material (B) relative to the total flow of steam (C) flowing into the reformer reactor (100), composition ratios of chemical compounds of fluid flowing between the reformer outlet (155) and the regenerator inlet (205), gas composition ratio between carbon monoxide (CO) and unconverted fuel gas flowing between the reformer outlet (155) and the regenerator inlet (205), gas composition ratio between carbon dioxide (CO.sub.2) and unconverted fuel gas flowing between the reformer outlet (155) and the regenerator inlet (205), and gas composition measurements in the hydrogen line (310).

18. The system according to claim 7, wherein the reformer reactor (100) includes an amount of the feed material (B), an amount of the steam (C) and an amount of the sorbent (A), wherein the feed material (B) comprises hydrocarbon containing fuel.

19. The system according to claim 7, wherein at least one of the reformer reactors (100) and the regenerator reactor (200) include a fluidized bed.

20. The system according to claim 8, wherein at least one of the reformer reactors (100) and the regenerator reactor (200) include a fluidized bed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Following drawings are appended to facilitate the understanding of the invention. The drawings show embodiments of the invention, which will now be described by way of example only, where:

[0093] FIG. 1 shows a system for producing hydrogen gas using sorbent in accordance with a first embodiment of the invention,

[0094] FIG. 2 shows the system of FIG. 1 where typical compositions, flows and temperatures are indicated,

[0095] FIG. 3 shows further details of a dosing system with a flow regulating device and a control system and

[0096] FIG. 4 shows a system for producing hydrogen gas using sorbent in accordance with a second embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0097] In the following, embodiments of the invention will be discussed in more detail with reference to the appended drawings. It should be understood, however, that the drawings are not intended to limit the invention to the subject-matter depicted in the drawings.

[0098] With particular reference to FIGS. 1 and 2, the inventive system 1 for production of hydrogen gas includes at least two reactors; a reformer reactor 100 and a regenerator reactor 200.

[0099] Firstly, a fluidized bed such as a bubbling fluidized bed (BFB), a catalyst such as a nickel catalyst and a sorbent A such as calcium oxide (CaO) are installed within the reformer reactor 100.

[0100] In order to control the temperature of the fluidized bed, a heat exchanger may be inserted into the reactor carrying cooling or heating fluids into the bed. However, as will be further explained below, such a heat exchanger may be omitted in this particular system since the required reformer reactor temperature to ensure the desired reactions there within may be achieved by feedback of heated regenerated sorbent A.

[0101] Fuel/feed material B such as natural gas/methane (CH.sub.4) flowing in a fuel material line 3 and a gas separable from CO.sub.2 such as steam C flowing in steam line 2 is guided into a common feed line 4 as a mixture D. The mixture D then enters the reformer reactor 100 via a reformer inlet 130. The temperature of the mixture D is typically between 200 C. and 300 C., for example 250 C. The pressure and flow rate of the mixture D may be between 1.0 bar absolute (bara) and 1.4 bara (typically 1.2 bara) and between 375 kg/h and 425 kg/h (typically 392 kg/h), respectively.

[0102] Moreover, typical values of temperature, pressure and flow rate within the fuel material line 3 and the steam line 2 are 120 C. (20 C.)/1.4 bara (0.4 bara)/73 kg/h (15 kg/h) and 120 C. (20 C.)/1.4 bara (0.4 bara)/318 kg/h (50 kg/h), respectively.

[0103] Alternatively, the fuel material B and the gas C may enter the reformer reactor 100 through separate inlets.

[0104] When the exemplary fluids and particulates are used, the following reactions take place in the reformer reactor 100:

Reforming: CH.sub.4(g)+H.sub.2O(g).Math.CO(g)+3H.sub.2(g) (2.1)

Shift: CO(g)+H.sub.2O(g).Math.CO.sub.2(g)+H.sub.2(g) (2.2)

Carbonation: CaO(s)+CO.sub.2(g).Math.CaCO.sub.3(s) (2.4)

[0105] The reforming and shift reactions are endo-and exothermal, respectively, and the carbonation reaction is exothermal.

Overall: CH.sub.4(g)+2H.sub.2O(g)+CaO(s).Math.CaCO.sub.3(s)+4H.sub.2(g) (2.5)

[0106] The CO.sub.2-gas is thus captured by sorbent A (here in the form of CaO particulates) within the fluidized bed to form used sorbent A* (here in form of CaCO.sub.3 particulates).

[0107] The produced H.sub.2-gas and the used sorbent A* is further guided through a separator transport line/tube 150 and into one or more separators 300 via reformer outlet(s) 155 and separator inlet(s) 304.

[0108] The separator 300 is configured to separate at least H.sub.2-gas from the used sorbent A* and is preferably of type inertial separator in which the used sorbent A* is removed from the gas using centrifugation as the driving separating force. Other separators well known in the art such as electrostatic separators may also achieve the desired separation.

[0109] During operation, separated H.sub.2-gas is continuously released into a hydrogen line 310 via a hydrogen outlet 315 arranged at the top part of the separator 300, while separated used sorbent A* is continuously released into a first regenerator transport line 320 via a used sorbent outlet 305 arranged at the lower part of the separator 300.

[0110] The separated H.sub.2-gas may be guided to a facility for further purification, for example by use of pressure swing adsorption, electrochemical purification or catalytic recombination. Typical temperature, pressure and flow rate in the hydrogen line 310 during operation are 600 C. (100 C.), 1.2 bara (0.4 bara) and 208 kg/h (40 kg/h). As further explained below, the release of gas into the hydrogen line 310 may, in addition to H.sub.2-gas, also include non-reacted gases from the reformer reactor 100 such as CO, CO.sub.2 and fuel gas B (e.g. CH.sub.4).

[0111] Separated used sorbent A* is guided from the used sorbent outlet 305 into a dosing system 400 configured to control the flow rate through the first regenerator transport line 320. Typical values of temperature, pressure and flow rate within the first regenerator transport line 320 during operation are 600 C. (100 C.), 1.2 bara (0.4 bara) and 2000 kg/h (600 kg/h).

[0112] The dosing system 400 may comprise a tank 410 having one or more tank inlets 405 and one or more tank outlets 415 for receiving used sorbent A* from the separator 300 and for discharging used sorbent A* from the tank 410, respectively.

[0113] The dosing system 400 may include a tank measuring device 411 for allowing monitoring of operation parameters such as amount of A* within the tank, presence and compositions of other species such as CO, CO.sub.2 and/or CH.sub.4, degree of moisture, etc. In FIGS. 1-4, such a tank measurement device 411 are shown coupled directly to the tank 410. However, measurements may be performed anywhere along the used sorbent transport lines 320, 430, as long as the desired parameters can be achieved. An example of such a tank measurement device 411 is a level measuring device which allows continuous monitoring of the volume of solids present within the tank 410.

[0114] After having been discharged from the tank 410 via the tank outlet(s) 415, the used sorbent A* is further guided through a second regenerator transport line 430, 430 into the regenerator reactor 200 for regenerating/calcinating the used sorbent A* back into the sorbent A and the CO.sub.2-gas. Typical temperature, pressure and flow rate of (primarily sorbent A) entering the regenerator reactor 200 are 850 C. (100 C.), 1.2 bara (0.4 bara) and 296 kg/h (50 kg/h), respectively.

[0115] Said regeneration reaction

CaCO.sub.3(s).Math.CaO(s)+CO.sub.2(g) (2.6)

is an endothermic reaction requiring supply of energy, usually in the form of added heat. At a typical pressure of 1.1-1.4 bara, a temperature range from 800 C. to 1100 C. may be sufficient temperature to initiate and maintain the regeneration reaction.

[0116] The regenerator reactor 200 comprises [0117] a regenerator vessel 201 having an internal volume with a fluidized bed (normally a BFB), [0118] a regenerator power source 220 for providing thermal energy to the used solvent A*, [0119] one or more regenerator inlets 205 for allowing entrance of the used solvent A* from the second regenerator transport line 430 into the regenerator vessel 201, [0120] one or more CO.sub.2 outlets 235 for allowing discharge of CO.sub.2 out of the regenerator vessel 201 and into one or more CO.sub.2 lines 240, [0121] one or more steam inlets 225 for allowing entrance of C (such as steam C guided from the steam line 2) into the regenerator vessel 201 from one or more steam regenerator lines 230, to fluidize the bed of the regenerator reactor and [0122] one or more sorbent outlets 215 for allowing discharge of hot regenerated sorbent A out of the regenerator vessel 201.

[0123] After discharge from the regenerator vessel 201, hot sorbent A is guided through a recycling line 210 back into the reformer reactor 100 via one or more sorbent inlets 120.

[0124] The steam C, entering the regenerator vessel 201 from the steam line 2, is pre-heated and has a typical temperature, pressure and flow rate of 750 C. (75 C.), 1.2 bara (0.4 bara) and 112 kg/h (20 kg/h). Upstream the split of the steam line 2 into a flow towards the feed line 4 and the steam regenerator line 230, the steam C has a typical temperature, pressure and flow rate of 120 C., 1.2 bara (0.4 bara) and 430 kg/h (75 kg/h).

[0125] The CO.sub.2 line 240 guides the discharged CO.sub.2 to an exterior location, typically a CO.sub.2 storage facility 600. Typical temperature, pressure and flow rate within the CO.sub.2 line 240 is 850 C. (75 C.), 1.2 bara (0.4 bara) and 296 kg/h (75 kg/h).

[0126] Furthermore, the dosing system 400 may comprise a valve (not shown) such as a one-way valve, configured to open or stop the flow of used sorbent A* into and/or out of the tank 410.

[0127] It is known that both kinetics of sorbent and operating pressure profoundly affects the production efficiency of SE-SMR in fluidized bed reactors [see publication Wang, Y. F.; Chao, Z. X.; Jakobsen, H. A. 3D Simulation of bubbling fluidized bed reactors for sorption enhanced steam methane reforming processes. J. Nat. Gas Sci. Eng. 2010, 2, 105-113 and publication Wang, Y. F.; Chao, Z. X.; Jakobsen, H. A. SE-SMR process performance in CFB reactors: Simulation of the CO.sub.2 adsorption/desorption process with CaO based sorbents. Int. J. Greenhouse Gas Control 2011, 5, 489-497].

[0128] The inventors hence realized that the ability of monitoring and controlling inter alia the capture efficiency of sorbent A and/or the flow rate R.sub.A* of used sorbent A* during the hydrogen production process would be highly advantageous.

[0129] FIG. 3 shows one exemplary configuration of the dosing system 400 of FIGS. 1 and 2, comprising a flow regulating device 440 for controlling the flow rate R.sub.A* of the used sorbent A* discharged from the separator 300 and a control system 500 for controlling various operating parameters such as said flow rate R.sub.A* and said capture efficiency of sorbent A.

[0130] In order to control the flow rate R.sub.A*, the flow regulating device 440 comprises in the illustrated exemplary configuration a screw conveyor 450 constituting part of the second regenerator transport line 430, thereby dividing the transport line into an upstream transport line section 430 and a downstream transport line section 430. To enforce rotational motions of the screw conveyor 450, a motor 460 is rotationally coupled to an end of the screw conveyor 450. Moreover, the ability of regulating the rotational velocity is achieved by connecting a variable speed drive/frequency regulator 470 to the motor 460.

[0131] The shown control system 500 is set in signal communication with the variable speed drive 470 for both digital control and monitoring.

[0132] In the exemplary configurations depicted in FIG. 1-4, the control system 500 may further receive and/or transmit operating signals from one or more of the other dynamics/components of the system 1 involved in the looped hydrogen production process such as [0133] receiving signals via a fuel material measurement line 501a, indicating flow rate of fuel material B (usually CH.sub.4) flowing in the fuel material line 3 to measure flow rate and/or composition of fuel material B into the reformer reactor 100, [0134] receiving signals via a steam measurement line 501c, indicating flow rate and/or composition of steam C (or other gas separable from CO.sub.2, see above) flowing in the steam line 2 into the reformer reactor 100, [0135] receiving signals via a steam measurement line 501d, indicating flow rate and/or composition of steam C (or other gas separable from CO.sub.2, see above) flowing in the steam line 2 into the regenerator reactor 200, [0136] receiving signals via a feed inlet measurement line 501b, indicating flow rate and/or composition of mixture D flowing in the feed line 4 into the reformer reactor 100, [0137] receiving signals via a reformer measurement line 501e, indicating volume and/or composition of gases and/or solids within the reformer reactor 100, [0138] receiving signals via a used sorbent measurement line 502, indicating flow rate and/or composition of fluids (primarily separated used sorbent A*) flowing in the second regenerator transport line 430 upstream and/or downstream 430 the flow regulating device 440, [0139] receiving signals via a CO.sub.2 measurement line 505, indicating flow rate and/or composition of gases (mainly CO.sub.2 and steam) discharged from the regenerator vessel 201 into CO.sub.2 line, [0140] transmitting signals via a heat regulation measurement line 504 to the regenerator power source 220 to set a desired power output for heating the used sorbent A* within the regenerator vessel 201, [0141] receiving signals via the heat regulation measurement line 504, or a separate measurement line from the regenerator power source 220, indicating the operating power supplied to the used sorbent A* within the regenerator vessel 201, [0142] receiving signals via a heat measurement line 506 from the regenerator vessel 201 to monitor the temperature of fluids within the regenerator vessel 201, [0143] receiving signals via a regenerated sorbent measurement line 507, indicating flow rate and/or composition of fluid (primarily regenerated sorbent A) discharged from the regenerator vessel 201 into the recycling line 210, receiving signals via a tank measurement line 508, or a separate measurement line directly from the tank 410, indicating operating parameters of the tank 410 such as volume and/or weight of solids/used sorbents A* and [0144] receiving signals via a gas measurement line 509, indicating flow rate and/or composition of gases flowing in the hydrogen line 310.

[0145] The control system 500 may receive and/or transmit signals wireless to one or more of the components mentioned above by installing necessary transmitters/receivers, thereby allowing the corresponding measurement line(s) to be omitted.

[0146] Moreover, the control system 500 may be connected to other parts of the system 1 to allow monitoring and/or control of these parts.

[0147] The flow rate and composition measurements may be performed by a shared measurement system within the control system 500 which includes the necessary measurement means such as a mass flow meter in case of flow rate measurements of used sorbent and regenerated sorbent A; and such as a gas chromatograph, a diode laser spectrometer and/or a combo-probe in case of gas composition measurements. Alternatively, or in addition, the measurements may be performed by dedicated measurement system for the individual measurement lines. As shown in FIG. 3 at least one of the measurements of the flows may require cooling 510 prior to measurements.

[0148] If the system 1 comprises the above-mentioned control system 500, various advantageous diagnostics may be obtained.

[0149] For example, when considering the reactions occurring in a typical SE-SMR process, CH.sub.4 and CO are consumed through the reforming reaction (2.1) and gas shift reaction (2.2) to produce CO.sub.2 and H.sub.2.

[0150] Hence, a reduced ability of the sorbent A to capture CO.sub.2 results in an increase in the amount of CO, CH.sub.4 and CO.sub.2 flowing out of the reformer reactor 100, separated from the used sorbent A* in the separator 300 and released into the hydrogen line 310.

[0151] A reduced ability of the sorbent A to capture CO.sub.2 during hydrogen production may thus be monitored by measuring the gas composition into the hydrogen line 310. If the measurements show a gradual increase in at least one of the gases CO, CH.sub.4 and CO.sub.2 it can be interpreted as a decline in the sorbent's ability to capture/adsorb CO.sub.2 within the reformer reactor 100.

[0152] As mentioned above, such gas composition measurements may be performed by installing appropriate gas composition measurement devices such as a gas chromatograph (not shown), wherein measurement signals are transmitted through the gas measurement line 509 to the automatic controller 500 which may show the results on a display (not shown) and/or used to calculate (via a processor within the controller 500) new set values for parameters such as energy supply from the regenerator power source 220 (via the heat measurement line 504) or the rotational speed v.sub.r of the screw conveyor 450 (via the flow regulation measurement line 503).

[0153] In the preceding description, various aspects of the system according to the invention have been described with reference to the illustrative embodiment. For purposes of explanation, specific numbers, systems and configurations were set forth in order to provide a thorough understanding of the system and its workings. However, this description is not intended to be construed in a limiting sense. Various modifications and variations of the illustrative embodiment, as well as other embodiments of the system, which are apparent to persons skilled in the art to which the disclosed subject matter pertains, are deemed to lie within the scope of the present invention.

LIST OF REFERENCE NUMBERS

[0154] 1 Hydrogen production system [0155] 2 Steam line [0156] 3 Fuel material line [0157] 4 Feed line [0158] 100 Reformer reactor [0159] 120 Sorbent inlet [0160] 130 Reformer inlet for mixture D of feed material B and steam C [0161] 150 Separator transport line [0162] 155 Reformer outlet [0163] 200 Regenerator reactor [0164] 201 Regenerator vessel [0165] 205 Regenerator inlet [0166] 210 Recycling line [0167] 215 Sorbent outlet [0168] 220 Regenerator power source/regenerator heat source [0169] 225 Steam inlet [0170] 230 Steam regenerator line [0171] 235 CO.sub.2 outlet [0172] 240 CO.sub.2 line [0173] 300 Separator [0174] 304 Separator inlet [0175] 305 Used sorbent outlet [0176] 310 Hydrogen line [0177] 315 Hydrogen outlet [0178] 320 First regenerator transport line [0179] 400 Dosing system [0180] 405 Tank inlet [0181] 410 Tank [0182] 411 Tank measurement device [0183] 415 Tank outlet [0184] 430 Second regenerator transport line (upstream 440) [0185] 430 Second regenerator transport line (downstream 440) [0186] 440 Flow regulating device [0187] 450 Screw conveyor [0188] 460 Motor/electric motor [0189] 470 Variable speed drive/frequency regulator [0190] 500 Control system/automatic controller [0191] 501a Feed inlet measurement line [0192] 501b Fuel material measurement line [0193] 501c Steam measurement line (reformer reactor) [0194] 501d Steam measurement line (regenerator reactor) [0195] 501e Reformer measurement line [0196] 502 Used sorbent measurement line [0197] 503 Flow regulation measurement line [0198] 504 Heat regulation measurement line [0199] 505 CO.sub.2 measurement line [0200] 506 Heat measurement line [0201] 507 Regenerate sorbent measurement line [0202] 508 Tank measurement line [0203] 509 Gas measurement line [0204] 510 Cooling system [0205] 600 CO.sub.2 storage/reservoir [0206] A Sorbent, CaO [0207] A* Used sorbent, CaCO.sub.3 [0208] B Feed material/natural gas [0209] C Steam [0210] D Feed mixture [0211] R.sub.A* Flow rate of used sorbent [0212] R.sub.A*,H Higher flow rate of used sorbent [0213] R.sub.A*,L Lower flow rate of used sorbent [0214] v.sub.r Rotation speed of screw conveyor [0215] v.sub.r;H Higher rotation speed of screw conveyor [0216] v.sub.r,L Lower rotation speed of screw conveyor [0217] Q Heat