Hydrogen generation system

Abstract

The present invention relates to a system for generating hydrogen gas H2. The system includes a reformer, a regenerator, a regenerator transfer line, and a recycle line. A regenerator power source system for supplying heat to the regenerator can include a gas burner and a return line for transferring at least a portion of the cooled exhaust off-gas G from the internal volume of the regenerator into the gas burner and / or the burner transfer line.

Description

Technical Field

[0001] The present invention relates to a system for generating hydrogen gas, comprising a reformer reactor, a regeneration reactor, a regenerator transfer line, and a recycle line. The regeneration reactor includes a regenerator power source system having a gas burner that emits exhaust off-gas, a heat exchanger, and a return line.

Background Art

[0002] Due to the sudden increase in the use of hydrogen fuel as an energy carrier, the supply of hydrogen to industrial users has become a major business worldwide.

[0003] Hydrogen can be extracted from fossil fuels and biomass, from water, or from a mixture of both. Currently, natural gas is the main source of hydrogen production.

[0004] Today, hydrogen fuel is produced through various methods. The most common methods are natural gas / methane reforming, coal gasification, and electrolysis. Other methods include solar-based processes and biological processes.

[0005] For example, see https: / / www.energy.gov / eere / fuelcells / hydrogen-fuel-basics.

[0006] Conventional SMR In conventional steam methane reforming (SMR), in the presence of a catalyst at high temperature (800 - 1000 °C) and high pressure (15 - 20 bar), when steam reacts with methane, a gas mixture consisting of hydrogen (H2) and carbon monoxide (CO) is created (Reaction Equation 2.1 below). By means of a water-gas shift reaction (Reaction Equation 2.2 below), which involves reacting steam with carbon monoxide using a catalyst, carbon dioxide (CO2) and additional hydrogen are then produced in a low temperature (300 - 400 °C) environment. The hydrogen gas is then separated from the CO2 in several steps, for example by pressure swing adsorption (PSA), until the desired hydrogen concentration is achieved.

[0007] The main reactions in conventional SMR are as follows.

[0008] Reforming: CH4(g) + H2O(g) ←→ CO(g) + 3H2(g) (2.1) Shift: CO(g) + H2O(g) ←→ CO2(g) + H2(g) (2.2) Overall: CH4(g) + 2H2O(g) ←→ CO2(g) + 4H2(g) (2.3) Conventional SMR has several drawbacks, such as the need for a large fixed bed to minimize pressure drop, deactivation of the catalyst due to carbon formation, and the need to maintain a high reaction temperature because only a portion of the heat of combustion is directly used in the process.

[0009] Sorption Enhanced SMR (SE-SMR) The SE-SMR process reduces the number of processing steps by adding a CO2 adsorbent such as calcium oxide (CaO) or dolomite to the reformer. In the presence of the adsorbent, CO2 is converted to solid carbonate (CaCO3) in an exothermic calcination process (Reaction Equation 2.4 below), resulting in product gas from the reformer consisting mainly of H2 and H2O, as well as small amounts of CO, CO2, and un-converted CH4 (fuel gas). By thus adding the adsorbent, a forward shift in Reactions 2.1 - 2.3 is brought about, and thus methane conversion and hydrogen yield are improved. The exothermic reaction results in an almost autothermal process operating at temperatures in the range of 550 - 650 °C.

[0010] The main reactions in SE-SMR, in addition to Reactions 2.1 - 2.2, are as follows.

[0011] Carbonation: CaO(s) + CO2(g) ←→ CaCO3(s) (2.4) Overall: CH4(g) + 2H2O(g) + CaO(s) ←→ CaCO3(s) + 4H2(g) (2.5) In continuous production, the carbonated adsorbent saturated with CO2 is then transferred to a regeneration reactor where it is exposed to high temperatures to ensure that the endothermic calcination reaction 2.6 occurs.

[0012] Calcination / Regeneration: CaCO3(s) ←→ CaO(s) + CO2(g) (2.6) Depending on the reactor configuration, the saturated adsorbent is heated to about 900 °C, enabling the endothermic reaction to proceed, i.e., releasing CO2 from the limestone containing carbonate, CaCO3.

[0013] Therefore, the heat sent to the regeneration reactor must both raise the temperature of the saturated adsorbent entering the bed and provide sufficient excess heat for the calcination reaction to be carried out. The heat source may be, for example, waste heat from a solid oxide fuel cell (SOFC). The adsorbent saturated with CO2 is typically referred to as "spent adsorbent".

[0014] The resulting regenerated adsorbent (CaO) is then returned to the reformer and transferred, and the CO2 released from the spent adsorbent is transferred to an external location, typically a CO2 handling or storage facility.

[0015] The above SE-SMR can be carried out in both fixed-bed reactors and fluidized-bed reactors. However, the use of fluidized-bed reactors is considered advantageous because they highly permit continuous supply and withdrawal of fluid / particles (thus enabling a higher degree of continuous operation), they have an effective and nearly isothermal heat distribution, they effectively mix chemical reactants, they are highly compatible with large-scale operation, their pressure drop is lower, and they have a higher degree of heat transfer between the bed and the immersed body.

[0016] The fluid medium for the SE-SMR regenerator can, in principle, be any gas that can be easily separated from CO2. Steam is considered ideal in this regard because it condenses at a significantly higher temperature than CO2. The fluid medium for the SE-SMR reformer is typically a mixture of steam and hydrocarbon gas having a steam-to-carbon ratio S / C of 2.5 / 1 to 4 / 1.

[0017] SE-SMR is known in the art. See, for example, U.S. Patent Publication No. 11,084,720 (B2) which discloses a method for generating power from hydrogen gas produced using sorption enhanced reforming. In this prior art system, the adsorbent material CaO in the reformer reactor serves to adsorb CO2 to form spent adsorbent in the form of CaCO3. The spent adsorbent is further guided to a regeneration reactor where the spent adsorbent can be indirectly heated using a heater to a temperature of 850 - 900 °C. Examples of heaters may be the use of pressure swing adsorption (PSA) off-gas and / or the use of natural gas fuel and an oxidant such as air. During the heating period, the adsorbent is regenerated due to the desorption of CO2. U.S. Patent Publication No. 8,241,374 (B2), WO2018 / 162675A3, WO2016 / 191678A1, and US2019 / 0112188A1 describe other examples of sorption enhanced SMR.

[0018] None of the systems described in the above patent publications provide information on improving the efficiency of the heating system for heating the spent adsorbent in the regeneration reactor.

Prior Art Documents

Patent Documents

[0019]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Non-Patent Documents

[0020]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0021] Therefore, at least one object of the present invention is to improve the efficiency of a heating system for heating spent adsorbent in a regenerator.

Means for Solving the Problems

[0022] The present invention is characterized by being described in the independent claims, while the dependent claims describe other features of the present invention.

[0023] In a first aspect, the present invention relates to a system for producing hydrogen gas H2.

[0024] The system includes at least one reformer reactor, at least one regeneration reactor, at least one regenerator transfer line, and at least one recycle line.

[0025] The reformer reactor has a sealed volume for containing a carbon dioxide capture adsorbent A that forms spent adsorbent A* when conditions for capturing carbon dioxide exist, such as a minimum pressure and / or a minimum temperature and / or a minimum amount per unit volume. The reformer reactor is configured to enable reforming of a feedstock B (such as a hydrocarbon fuel) and steam C (i.e., water mostly in the gas phase) to produce a reformed gas mixture containing hydrogen gas H2 and carbon dioxide CO2. The reformer reactor includes at least one reformer inlet for supplying at least one of the feedstock B and the steam C into the reformer reactor, and at least one reformer outlet for discharging the spent adsorbent A* and the hydrogen gas H2. More preferably, the reformer reactor includes at least two reformer inlets including a feedstock inlet and a steam inlet. The reformer reactor can include an additional inlet for supplying the carbon dioxide capture adsorbent A into the reformer reactor.

[0026] Specific examples of carbon dioxide capture adsorbent A and spent adsorbent A* are calcium oxide CaO and calcium carbonate CaCO3, respectively.

[0027] The regenerator includes a regenerator vessel, at least one regenerator inlet for receiving at least a portion of the spent adsorbent A*, and at least one regenerator power source system configured to supply energy to the received spent adsorbent A* to enable the release of carbon dioxide CO2 and thereby regenerate the adsorbent A, and at least one regenerator outlet for discharging the regenerated adsorbent A.

[0028] The regenerator power source system includes one or more gas burners for ejecting the exhaust off-gas G, and the gas burner includes at least one first burner inlet for supplying the first burner gas E into the gas burner and at least one burner outlet for ejecting the exhaust off-gas G generated inside the gas burner.

[0029] When the gas burner is disposed outside the regenerator vessel, the gas burner also includes at least one burner transfer line for transferring the exhaust off-gas G from the burner outlet to the internal volume portion of the regenerator vessel.

[0030] The regenerator power source system can also include at least one return line for transferring at least a portion of the cooled exhaust off-gas G from the internal volume portion of the regenerator vessel into the gas burner and / or the burner transfer line.

[0031] The first burner gas E is preferably an oxygen-containing gas / gas mixture such as oxygen gas O2 and / or air.

[0032] In an exemplary configuration, the regenerator power source system further comprises a heat exchanger configured to transfer heat from the exhaust off-gas G to the internal volume of the regenerator reactor vessel, and the return line is configured to transfer a portion of the cooled exhaust off-gas G flowing downstream of the heat exchanger.

[0033] In another exemplary configuration, the gas burner comprises at least one second burner inlet for supplying / introducing a second burner gas F different from the first gas E, such as, for example, natural gas and / or hydrogen gas, into the burner.

[0034] At least one of the first burner gas E and the second burner gas F is combustible.

[0035] The exhaust off-gas G generated inside the gas burner may be the result of a reaction between the first gas E and the second gas F.

[0036] The temperature of the exhaust off-gas G is typically much higher than the temperature of the first gas E and (if present) the second gas F. For example, while the first gas E and the second gas F may have a temperature in the range of 5 to 25 °C, the exhaust gas G may have a temperature in the range of 1000 to 1200 °C.

[0037] At least a portion of the regenerated adsorbent A can be transferred from the regenerator outlet into the reformer reactor, either into one or more reformer inlets or via one or more dedicated recycle inlets.

[0038] In yet another exemplary configuration, the system further comprises an automatic controller that signal communicates with the regenerator power source via a power source communication line.

[0039] The controller can be configured to automatically control the operation of the regenerator power system based on one or more of the following parameters.

[0040] - Flow rate of the first burner gas E into the burner - Flow rate of the second burner gas F into the burner, if applicable - Flow rate of the feedstock B flowing into the reformer - Flow rate of the steam C flowing into the reformer - Flow rate of the mixture of the feedstock B and the steam C flowing into the reformer - Flow rate of the fluid containing the spent adsorbent A* and CO2 flowing into the regeneration reactor vessel - Flow rate of the hydrogen gas flowing out from the separator, if applicable - Temperature inside the regeneration reactor vessel - Temperature of the exhaust off-gas G flowing into and / or out of the regeneration reactor vessel, for example, upstream and / or downstream of a heat exchanger - Flow rate of the exhaust off-gas G flowing towards and / or out of the regeneration reactor vessel, for example, upstream and / or downstream of a heat exchanger In yet another exemplary configuration, the return line comprises an exhaust off-gas control valve configured to adjust the flow rate R of the exhaust off-gas G flowing through the return line. The exhaust off-gas control valve can comprise a control valve controller configured to control the flow rate R of the exhaust off-gas G. G G

[0041] In yet another exemplary configuration, the return line comprises a flow sensor configured to measure the flow rate R of the exhaust off-gas G flowing through the return line. G

[0042] In yet another exemplary configuration, the system further comprises an automatic controller that signal-communicates with the flow sensor via a flow controller communication line. The controller can be configured to automatically control the exhaust off-gas control valve based on the flow rate R measured by the flow sensor. G

[0043] ​​​​In yet another exemplary configuration, the heat exchanger outlet temperature T of the exhaust off-gas G leaving the heat exchanger he is less than 90%, more preferably less than 85%, for example 82%, of the heat exchanger inlet temperature T hi entering the heat exchanger, and any heat exchanger is configured accordingly.

[0044] In yet another exemplary configuration, the system further comprises a second return line for transferring a portion of the cooled exhaust off-gas G from the internal volume of the reformer reactor vessel, such as from the heat exchanger, to an off-gas treatment system disposed outside the reformer reactor vessel. The off-gas treatment system is typically a CO2 treatment system.

[0045] In yet another exemplary configuration, the system further comprises a second fuel material line for transferring a portion of the feedstock B, such as natural gas or biogas going into the reformer, also into the gas burner. Such a second fuel material line may be in fluid communication with a second burner inlet.

[0046] Thus, the gas entering the burner (in addition to a combustible gas such as oxygen / air) may be a mixture of a gas F different from the feedstock B or the feedstock B alone.

[0047] In yet another exemplary configuration, the system further comprises a hydrogen purifier configured to produce pure H2, such as a pressure swing adsorption (PSA) hydrogen purifier, and a hydrogen transfer line for transferring the hydrogen-containing gas produced in the reformer reactor into the hydrogen purifier, typically via a separator configured to separate the spent adsorbent A* and hydrogen H2.

[0048] In yet another exemplary configuration, the system further comprises a hydrogen purifier transfer line for transferring the off-gas produced within the hydrogen purifier into the gas burner, for example via a second burner inlet. The gas entering the burner (in addition to a combustible gas such as oxygen / air) may be a mixture of the off-gas, the feedstock B, and a gas F different from the feedstock B.

[0049] In yet another exemplary configuration, when the gas entering the gas burner has a temperature of less than 100°C, preferably less than 50°C, more preferably less than 25°C, for example 10°C, the temperature of the exhaust off-gas G ejected from the burner outlet is higher than 900°C, preferably higher than 1000°C, more preferably higher than 1050°C, for example 1100°C, and the gas burner is configured accordingly.

[0050] In yet another exemplary configuration, the reformer and / or the regenerator includes a fluidized bed.

[0051] In yet another exemplary configuration, the reformer is selected from the group consisting of the following.

[0052] (i) A reformer (100) configured to support sorption-enhanced steam methane reforming (ii) A reformer (100) configured to support sorption-enhanced water gas shift (iii) A combination of (i) and (ii) In yet another exemplary configuration, the system includes a separator configured to separate the spent adsorbent A* from the hydrogen gas H2 ejected from the reformer. The separator includes a separator inlet for supplying the hydrogen gas H2 and the spent adsorbent A* into the separator, and a separator outlet for ejecting the separated spent adsorbent A*. In this exemplary configuration, the system can further include a separator transfer line for transferring the spent adsorbent A* and the hydrogen gas H2 from the reformer outlet to the separator inlet, a regenerator transfer line for transferring the flow of the spent adsorbent A* from the separator outlet to the regenerator inlet, and a hydrogen transfer line for transferring the separated hydrogen to a hydrogen purifier.

[0053] In a second aspect, the present invention relates to a method for producing hydrogen gas H2 using a system as described above.

[0054] The method includes the following steps.

[0055] A step of introducing a feedstock B (such as a hydrocarbon fuel) and steam C into a reformer through one or more reformer inlets, the reformer also containing a carbon dioxide capture adsorbent A (such as calcium oxide CaO), and preferably also a catalyst for catalyzing the reforming reaction B A step of reforming the feedstock B and steam C in the reformer to produce a reformed gas mixture and a spent adsorbent A* (such as calcium carbonate CaCO3) C A step of transferring at least a portion of the spent adsorbent A* and at least a portion of the reformed gas mixture from the reformer to the regenerator through a transfer line D A step of introducing a first burner gas E and preferably also a second burner gas F into a gas burner at a burner inlet temperature T bi such that the gas burner is configured to produce an exhaust offgas G at a burner outlet temperature T bj higher than the burner inlet temperature T bo for the first burner gas E and, if any, the second burner gas F E A step of transferring the exhaust offgas G from the gas burner to the internal volume of a regenerator vessel (201), for example, to a heat exchanger disposed within the internal volume, such that the gas burner is configured to cause heat to release at least a portion of carbon dioxide CO2 to the spent adsorbent A* within the regenerator vessel to at least partially regenerate the carbon dioxide capture adsorbent A of step A G A step of transferring at least a portion R bo of the flow of exhaust gas G from the heat exchanger outlet away from the internal volume of the regenerator vessel towards the gas burner to cool the exhaust offgas G from the burner outlet temperature T hi to the regenerator inlet temperature T G H A step of transferring the carbon dioxide capture adsorbent A regenerated in step F from the regenerator to the reformer, if any, through a recycle line Regenerator inlet temperature T hi ​should be sufficient to heat the spent adsorbent A* such that carbon dioxide CO2 is released.

[0056] The burner outlet temperature T bo should preferably be at least 50 times higher than the burner inlet temperature T bj .

[0057] The method can further include at least one of the following steps.

[0058] - The step of also introducing the feedstock B supplied into the reformer into the gas burner via a second fuel feed line - The step of transferring the hydrogen-containing gas produced in the reformer into at least one hydrogen purifier, such as a pressure swing adsorption (PSA) hydrogen purifier, via one or more hydrogen transfer lines - The step of introducing the off-gas produced in at least one hydrogen purifier into the gas burner via a hydrogen purifier transfer line - The step of transferring the spent adsorbent A* and the reformed gas mixture from the reformer to at least one separator configured to separate the spent adsorbent A* from hydrogen gas H2 via a separator transfer line - The step of separating the spent adsorbent A* from hydrogen gas H2 by using at least one separator - The step of transferring the separated hydrogen gas H2 into at least one hydrogen purifier via a hydrogen transfer line - The step of introducing the off-gas produced in at least one hydrogen purifier into the gas burner via one or more hydrogen purifier transfer lines - In step C, transferring the separated spent adsorbent A* from the separator to the regenerator via at least one regenerator transfer line equipped with an adjustment device configured to enable adjustment operated by the user of the flow rate R A* of the spent adsorbent A*. - Monitoring the flow rate R A* of the spent adsorbent A* flowing into the regenerator inlet, and the flow rate RA* When the variation of [the relevant parameter] exceeds a predetermined flow rate threshold value, in order to ensure that the burner outlet temperature T bo is maintained within a predetermined temperature threshold value during operation, by using an automatic controller that communicates with the regenerator power source, the step of adjusting the flow rate of the exhaust off-gas G flowing upstream and / or downstream of the heat exchanger The transfer of the hydrogen-containing gas into the hydrogen purifier is typically carried out after separating the used adsorbent A* in the separator.

[0059] The gas entering the burner may be a mixture of off-gas, feedstock B, and another gas F, in addition to a combustible gas such as oxygen / air.

[0060] The following drawings are attached to facilitate the understanding of the present invention. The drawings show embodiments of the present invention, but are described here for illustrative purposes only.

Brief Description of the Drawings

[0061]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0062] In the following, embodiments of the present invention will be discussed in more detail with reference to the accompanying drawings. However, it should be understood that the drawings are not intended to limit the present invention to the subject matter depicted therein.

[0063] Referring to FIGS. 1-5, an exemplary system 1 for generating hydrogen gas comprises the following main components.

[0064] - A reformer 100 containing calcium oxide (CaO) as a CO2 capture adsorbent A. In it, an adsorbent A feed gas (e.g., natural gas and / or biogas) B and steam C are reformed in an exothermic calcination process into a reformed gas mixture containing hydrogen gas H2 and spent adsorbent A* in the form of solid calcium carbonate (CaCO3).

[0065] - A regenerator 200 having a regenerator vessel 201 and a burner system 220 - Regenerator transfer lines 150, 320 for transferring calcium carbonate (CaCO3) of the reformed gas mixture into the regenerator vessel 201 - A recycle line 210 for transferring the regenerated calcium oxide (CaO) into the reformer 100 First, steam C and the feed gas B are each transferred to the reformer 100 through a dedicated steam inlet line 2 and a dedicated fuel material inlet line 3, respectively. Before being supplied through a reformer inlet 130 into the internal volume portion of the reformer 100, steam C and the feed gas B are supplied into a common supply line 4, thereby creating a supply mixture D. However, it is also possible to assume that the two fluids B, C are supplied into the reformer 100 through a separator inlet.

[0066] Referring particularly to FIG. 5, while the typical temperature of the operating supply mixture D is 250°C, the typical temperature in the reformer 100 is between 550°C and 650°C.

[0067] Figure 2 shows the burner system 220 in more detail. In this exemplary configuration, the burner system 220 includes a gas burner 221 through which an oxidizing gas E such as oxygen gas O2 or air flows therein through an oxygen line 5 and a first burner inlet 222, and a combustion gas F flows through a burner supply line 6 and a second burner inlet 222'. The inflowing gases E, F are combusted in the gas burner 221, and typically, a high-temperature exhaust off-gas G of CO2 and water vapor H2O is ejected at a high temperature T bo through a gas burner outlet 223 into a burner transfer line 225.

[0068] The temperatures of the inflowing gases E, F are typically in the range of 5 to 25 °C (for example, 10 °C), and the temperature of the exhaust off-gas G is typically in the range of 1000 to 1200 °C (for example, 1100 °C).

[0069] The exhaust off-gas G is further guided through a heat exchanger 224 disposed within the regenerator vessel 201 via a heat exchanger inlet 224' and a heat exchanger outlet 224''. To regenerate the adsorbent A (CaO), the used adsorbent A* (CaCO3) and any bed material within the regenerator vessel 201 must reach a temperature between 800 °C and 900 °C, preferably about 850 °C. Further, an appropriate release of CO2 can be ensured by a gas-phase CO2 partial pressure higher than 0 bar, for example, about 0.2 bar.

[0070] It is not desirable to heat the used adsorbent A* (CaCO3) significantly higher than the required temperature. This is because this may accelerate the deterioration of the adsorbent due to sintering, agglomeration, and / or pore closure.

[0071] The regenerated adsorbent A is transferred through an adsorbent outlet 215 and a recycle line 210 into the adsorbent inlet 120 of the reformer 100, thereby realizing adsorbent replenishment (see Figure 1).

[0072] As further shown in FIG. 2, the cooled exhaust off-gas G exiting the heat exchanger 224 via the heat exchanger outlet 224'' is guided out of the regeneration reactor vessel 201 via the return line 226. The cooled exhaust off-gas G typically has a temperature of about 900°C.

[0073] Outside the regeneration reactor vessel 201, the return line 226 is split into two lines 226', 226'', namely, the burner return line 226' and the reservoir return line 226''. The burner guide line 226' guides the cooled exhaust off-gas G at a flow rate R G to the downstream part of the gas burner 221, for example, at the gas burner outlet 223 or just upstream of the gas burner outlet 223, and / or directly to the burner transfer line 225, thereby cooling the hot exhaust off-gas G exiting the gas burner 221. The cooled exhaust off-gas G entering the reservoir return line 226'' is guided to the reservoir 600, which is a CO2 treatment system that typically also receives gases such as CO2 directly from the regeneration reactor vessel 201 via the CO2 outlet 235 and the CO2 line 240.

[0074] Still referring to FIG. 2, the flow rate R G can be adjusted by placing the exhaust gas control valve 227 in the burner return line 226'. The valve 227 can be adjusted by an exhaust gas flow controller 227' that receives a command signal from the control system 500 via the heat adjustment communication line 504. Note that the flow rate R G can also be adjusted by attaching one or more valves 227 in the return line 226 upstream of the split and / or in the reservoir return line 226''.

[0075] The flow rate R of the cooled exhaust gas G GTo measure in real time, a flow sensor 227'' can be attached. In Figure 2, such a flow sensor 227'' is attached in signal communication and / or fluid communication with the burner return line 226' for direct flow measurement. Further, the heat regulation communication line 504 can be split into a flow valve adjustment line 504' for controlling the flow sensor 227'' and a flow sensor measurement line 504'' for receiving flow data from the flow sensor 227''. The flow sensor adjustment line 504' and the flow sensor measurement line 504'' can also or alternatively be configured as separate lines from the control system 500.

[0076] Finally, the heat regulation communication line 504 can be split into a burner adjustment line 504''' to transmit heat-related data to the gas burner 221 that can be reused, for example, to adjust the flow of the first gas E (such as oxygen or air) and / or the second gas F (such as natural gas), thereby controlling the generation of hot exhaust gas G.

[0077] The adjustment of gases E and F can alternatively or additionally be the result of the measured flow rate R from the flow sensor 227'''. G of.

[0078] The same burner adjustment line 504''' can be used to send a signal having information about the state of the burner system 220 to the control system 500.

[0079] The control system 500 can also receive a temperature-related signal from the temperature sensor 250 via the regenerator temperature measurement line 511. The temperature sensor 250 is configured to measure the temperature state within the regeneration reactor vessel 201, such as the adsorbent temperature and / or any bed temperature. Such temperature measurement, and typically in combination with the flow rate measurement by the flow sensor 227'', can determine new settings for the exhaust gas control valve 227 and / or the burner system 220 (via the control system 500 and respective lines 504, 504'', 504''').

[0080] The characteristics such as the flow rate, temperature, and composition of the gas (typically CO2) transmitted from the regeneration reactor vessel 201 to the reservoir 600 can be measured by a suitable measurement tool, and for further processing, the measurement data can be transmitted to the control system 500 via the CO2 measurement line 505. For example, data such as the temperature adjustment of the burner system 220 as described above and / or the flow rate / composition of the feed mixture D into the reformer 100 can determine the parameter settings of other parts of the hydrogen generation system 1.

[0081] The reformed gas mixture ejected from the reformer 100 through the reformer outlet 155 is guided to the separator 300 by the separator transfer line 150. The separator 300 may be centrifugal and is configured to separate at least the spent adsorbent A* from the hydrogen gas (H2). The reformed gas mixture can contain other fluids other than hydrogen gas and the spent adsorbent A*, such as carbon monoxide (CO) and feedstock B for example.

[0082] The separator 300 includes a separator inlet 304 for supplying the reformed gas mixture into the separator 300, in particular a carbonate outlet 305 for ejecting the separated spent adsorbent A*, and in particular a hydrogen outlet 315 for ejecting the separated hydrogen gas.

[0083] The separated spent adsorbent A* is further transferred to the regenerator inlet 205 of the regeneration reactor vessel 201 via the regenerator transfer line 320.

[0084] Similarly, the separated hydrogen gas (and any other gases such as CO, CO2, and feedstock B) is transferred to the pressure swing adsorption (PSA) unit 700 via the hydrogen line 310 for further gas purification.

[0085] The characteristics such as the flow rates, pressures, temperatures, and compositions of both the spent adsorbent A* and the separated H2 can be measured by suitable measurement tools, and the measurement data can be transmitted to the control system 500 via the spent adsorbent measurement line 502 and the gas measurement line 509 respectively. For example, other parts of the hydrogen generation system 1 can be adjusted using the information regarding the characteristics, such as the temperature adjustment of the burner system 220 as described above, and / or the flow rate / composition of the feed mixture D into the reformer 100.

[0086] Measurement data regarding the characteristics such as the temperature, pressure, and composition from within the regeneration reactor vessel 201 can also be directly sent to the control system 500 via the thermal measurement line 506.

[0087] The control system 500 can also receive the said characteristics from the recycle line 210 via the regenerated adsorbent measurement line 507.

[0088] With particular reference to FIGS. 3 and 4, the combustion gas F flowing through the burner supply line 6 can be caused to flow entirely or partially from the feedstock B flowing into the reformer 100 by arranging a second fuel feed line 228 that is in fluid communication between the fuel feedstock inlet line 3 and the burner supply line 6. To control this flow of the feedstock B into the gas burner 221, a fuel feedstock control valve 229 can be installed in the second fuel feed line 228. Further, the automatic control of the fuel feedstock control valve 229 can be achieved by attaching a fuel control line 512 between the control system 500 and the valve 229, thereby ensuring signal communication therethrough.

[0089] As seen in FIG. 4, another source of the combustion gas F can be provided by arranging one or more hydrogen purifier off-gas lines 701 between the PSA unit 700 and the burner supply line 6. For the feedstock B, the off-gas / tail-gas flow from the PSA unit 700 can be controlled by a dedicated control valve (not shown).

[0090] Similar to the second fuel material line 228, in order to enable steam to enter the reformer vessel 201, the steam regeneration line 231 can be attached in fluid communication between the steam inflow line 2 and the steam inlet 230 into the reformer vessel 201.

[0091] The control system 500 can also receive measurement data that provides information on the characteristics in any other part of the hydrogen generation system 1. As shown in FIGS. 3 and 4, the system 1 can further include the following.

[0092] - A supply inflow measurement line 501a that ensures signal communication between the fuel material inflow line 3 and the control system 500 - A fuel material measurement line 501b that ensures signal communication between the supply line 4 and the control system 500 - A steam measurement line 501c that ensures signal communication between the steam inflow line 2 and the control system 500 - Another steam measurement line 501d that ensures signal communication between the steam regenerator line 231 and the control system 500 - A reformer measurement line 501e that ensures signal communication between the reformer 100 and the control system 500 For example, the reformer measurement line 501e can transmit a signal carrying information regarding at least one of pressure, temperature, and composition to the control system 500.

[0093] It is also possible to envision a signal communication line from the separator transfer line 150 and / or the hydrogen purifier off-gas line 701 to the control system 500.

[0094] The following describes an example of specific operations to ensure that sufficient energy is transferred from the burner system 220 described above to the heat exchanger 224 and to achieve the temperature within the reformer vessel 201 that enables effective release of CO2 from CaCO3 (spent adsorbent A*) to regenerate CaO (adsorbent A).

[0095] The heat exchanger 224 may be an in-bed tube bundle heat exchanger, and the regenerator 200 may include a fluidized bed.

[0096] From modeling studies and based on learning from the prototype plant, the ideal gas temperature at the heat exchanger tube bundle inlet 224’ is about 1100 °C and drops to about 900 °C at the tube bundle outlet 224’’.

[0097] At the designed solid circulation rate, the desired heat input is about 10 kW / kg H2 / h production capacity (about 350 kW for a 30 kg H2 / h production capacity). As the solid circulation rate increases or decreases, the heat input of the exhaust gas G proceeding to the regenerator 200 through the burner transfer line 225 can be automatically adjusted by using the system described above.

[0098] An effective input parameter for such automatic adjustment is the regenerator bed temperature. Due to the intensity of mixing in the fluidized bed, the bed temperature responds rapidly to fluctuations in the solid circulation rate R A* of.

[0099] Thus, while changes in the bed temperature result in a rapid response in the heat supply from the burner system 220, the correct gas temperature is maintained at the heat exchanger tube bundle inlet 224’. The heat supply from the burner system 220 is a direct function of the rate of combustion of the fuel in the internal volume of the gas burner 221 and is adjusted by the addition of fuel from the oxygen line 5 and the burner supply line 6, which is in turn controlled by fuel flow regulation, for example, by automatic adjustment of the flow through the fuel material control valve 229.

[0100] The gas burner 221 is set to prioritize the PSA tail gas proceeding through the PSA tail gas line 701 from the PSA unit 700 and can add new natural gas through the burner supply line 6 when this is not sufficient. Thus, the main fuel flow adjustment is achieved by controlling the natural gas flow by control valves in one or more of the burner supply line 6, the second fuel material line 228, and the PSA tail gas line 701.

[0101] For example, when the solid circulation rate R in the regenerator transfer line 320 A* and / or the fluctuations in the bed temperature in the regenerator reactor vessel 201 are detected, the control system 500 adjusts the new natural gas flow into the burner 221, thereby controlling the heat input to the regenerator 200.

[0102] The oxidant for the burner system 220 is typically produced by a second PSA, VPSA, or cryogenic separation, rich in oxygen and depleted in nitrogen. The oxidant flow is adjusted by the total fuel flow, such that there can be excess oxygen in the combustion chamber for complete oxidation of all combustible gas compounds.

[0103] The combustion temperature in the oxygen - fuel burner is generally very high compared to burners supplied with air (2000 - 2500 °C) and thus far exceeds the limits of the heat exchanger tube bundle material construction. Therefore, a combustion gas recirculation system has been developed to improve the overall efficiency of the burner system. The recirculation system returns most (about 90% - v) of the combustion gas exiting the in - bed heat exchanger in the regenerator 200 back to the burner combustion chamber, thus (1) increasing the gas flow to the heat exchanger and (2) reducing the gas flow temperature to the desired level. To overcome the pressure loss, a high - temperature fan can be installed in the combustion gas line between the heat exchanger outlet 224’’ and the burner return pipes 226’, 226’.

[0104] The flow split between the recycle back to the burner and the flow to the downstream system can be controlled by the back pressure of the downstream system.

[0105] In the foregoing description, various aspects of the system according to the present invention have been described with reference to embodiments for purposes of illustration. For purposes of illustration, specific numbers, systems, and configurations have been described in order to provide a complete understanding of the system and its operation. However, this description is not intended to be construed in a limiting sense. Various modifications and variations of the embodiments for purposes of illustration as well as other embodiments of the system will be apparent to those skilled in the art to which the disclosed subject matter pertains and are considered to be within the scope of the present invention.

Explanation of Signs

[0106] 1 Hydrogen generation system 2 Steam inflow line 3 Fuel material inflow line 4 Supply line 5 First burner inflow line / Oxygen line 6 Second burner inflow line / Burner supply line 100 Reformer 120 Adsorbent inlet 130 Reformer inlet for mixture D of feedstock B and steam C 150 Separator transfer line 155 Reformer outlet 200 Regenerator 201 Regenerator vessel 205 Regenerator inlet 210 Recycling line 215 Regenerator outlet / Adsorbent outlet 220 Regenerator power system / Regenerator heat system / Burner system 221 Gas burner 222 First gas burner inlet / First burner inlet 222’ Second gas burner inlet / Second burner inlet 223 Gas burner outlet 224 Heat exchanger 224’ Heat exchanger inlet 224’’ Heat exchanger outlet 225 Burner transfer line 226 Return line 226’ Burner return line 226’’ CO2 return line 227 Exhaust gas control valve 227’ Exhaust gas flow controller 227’’ Flow sensor 228 Second fuel material line 229 Fuel material control valve 230 Steam inlet 231 Steam regenerator line 235 CO2 outlet 240 CO2 line 250 Temperature sensor for measuring bed temperature 300 Separator 304 Separator inlet 305 Spent adsorbent outlet / carbonate outlet 310 Hydrogen line 315 Hydrogen outlet 320 Regenerator transfer line 400 Dosing system 405 Tank inlet 410 Tank 411 Tank measurement device 415 Tank outlet 450 Screw conveyor 460 Motor / electric motor 470 Variable speed drive / frequency regulator 500 Control system / automatic controller 501a Feed inflow measurement line 501b Fuel material measurement line 501c Steam measurement line (reformer) 501d Steam measurement line (regenerator) 501e Reformer measurement line 502 Spent adsorbent measurement line 503 Flow adjustment measurement line 504 Heat adjustment communication line 504’ Flow sensor adjustment line 504’’ Flow sensor measurement line 504’’’ Burner adjustment line 505 CO2 measurement line 506 Thermal measurement line 507 Regenerated adsorbent measurement line 508 Tank measurement line 509 Gas measurement line 510 Cooling system 511 Regenerator temperature measurement line 512 Fuel control line 600 CO2 storage / storage tank / CO2 treatment system 700 Hydrogen purifier / pressure swing adsorption (PSA) unit 701 Hydrogen purifier off-gas line / PSA tail gas line A Adsorbent, CaO A* Spent adsorbent, CaCO3 B Feedstock / Natural gas C Steam D Feed mixture E First gas / Oxygen F Second gas / Natural gas / PSA off-gas / Natural gas and PSA off-gas G Exhaust gas from gas burner H Off-gas from hydrogen purifier R A* Flow rate of spent adsorbent R A*,H Greater flow rate of spent adsorbent R A*,L Smaller flow rate of spent adsorbent R G Flow rate of exhaust off-gas v r Rotation speed of screw conveyor v r,H Faster rotation speed of screw conveyor v r,L Slower rotation speed of screw conveyor Q Heat T bi Temperature of inlet gases E, F T bo Burner outlet temperature / Maximum temperature of exhaust off-gas G / Exhaust gas G T hi Regenerator inlet temperature / Heat exchanger inlet temperature

Claims

1. A system (1) for generating hydrogen gas, comprising: A reformer reactor (100) for containing a carbon dioxide capture adsorbent (A), The reforming reactor (100) is configured to enable reforming of the feedstock (B) and steam (C) in order to produce a reformed gas mixture containing hydrogen gas (H ２ ), and carbon dioxide gas (CO ２ ). The reforming reactor (100) has a reformer inlet (130) for supplying at least one of the feedstock (B) and the steam (C) into the reforming reactor (100), and the hydrogen gas (H ２ ), and a reformer outlet (155) for ejecting the spent adsorbent (A*). The spent adsorbent (A*) is defined as a product resulting from the reaction between the carbon dioxide capture adsorbent (A) and carbon dioxide (CO ２ ).), a reforming reactor (100), A regeneration reactor (200), A regeneration reactor vessel (201), A regenerator inlet (205) for receiving at least a portion of the used adsorbent (A*), Providing sufficient heat to the received used adsorbent (A*) to enable the release of carbon dioxide (CO ２ ) from the used adsorbent (A*) and configured to regenerate the carbon dioxide capture adsorbent (A), a regenerator power source system (220); A regeneration reactor (200) comprising a regenerator outlet (215) for ejecting the regenerated adsorbent (A); A regenerator transfer line (150, 320) for transferring the used adsorbent (A*) from the reformer outlet (155) to the regenerator inlet (205), A recycle line (210) for transferring at least a portion of the regenerated adsorbent (A) from the regenerator outlet (215) into the reformer reactor (100), The regenerator power source system (220) includes A gas burner (221), A first burner inlet (222) for supplying a first burner gas (E) into the gas burner (221), A burner outlet (223) for ejecting exhaust off-gas (G) generated inside the gas burner (221), A gas burner (221) comprising a burner transfer line (225) for transferring the exhaust off-gas (G) from the burner outlet (223) to the internal volume portion of the regeneration reactor vessel (201), A system (1) comprising a return line (226, 226') for transferring at least a portion of the cooled exhaust off-gas (G) from the internal volume portion of the regeneration reactor vessel (201) into at least one of the gas burner (221) and the burner transfer line (225).

2. The regenerator power source system (220) further comprises a heat exchanger (224) configured to transfer heat from the exhaust off-gas (G) to the internal volume portion of the regeneration reactor vessel (201), The return line (226, 226') is configured to transfer a portion of the cooled exhaust off-gas (G) from the heat exchanger (224), according to the system (1) of Claim 1.

3. The gas burner (221) further comprises a second burner inlet (222') for supplying a second burner gas (F) into the gas burner (221), according to the system (1) of Claim 1 or 2.

4. Further comprising an automatic controller (500) for signal communication with the regenerator power source system (220), The automatic controller (500) is configured to: The flow rate of the first burner gas (E) into the gas burner (221), The flow rate of the feedstock (B) flowing into the reformer (100), The flow rate of steam (C) flowing into the reformer (100), The flow rate of the mixture of the feedstock (B) and steam (C) flowing into the reformer (100), The flow rate of the spent adsorbent (A*) flowing into the regeneration reactor vessel (201), The temperature inside the regeneration reactor vessel (201), The temperature of the exhaust off-gas (G) flowing into and / or out of the regeneration reactor vessel (201), Based on at least one of the flow rate of the exhaust off-gas (G) into and / or out of the regeneration reactor vessel (201), the operation of the regenerator power source system (220) is automatically controlled. The system (1) according to any one of claims 1 to 3.

5. The return line (226') is provided with an exhaust off-gas control valve (227) configured to adjust the flow rate (R Ｇ ) of the exhaust off-gas (G) flowing through the return line (226'), the system (1) according to any one of claims 1 to 4.

6. The exhaust off-gas control valve (227) includes a control valve controller (227') configured to control the flow rate (R Ｇ ) of the exhaust off-gas (G). The system (1) according to claim 5.

7. The return line (226') comprises a flow sensor (227'') configured to measure the flow rate (R Ｇ ) of the exhaust off-gas (G) flowing through the return line (226'). The system (1) according to any one of claims 1 to 6.

8. An automatic controller (500) for signal communication with the flow rate sensor (227''), The automatic controller (500) is based on the flow rate (R Ｇ ) measured by the flow rate sensor (227''), and is configured to automatically control the exhaust off-gas control valve (227). The system (1) according to claim 7, which further comprises an automatic controller (500), is dependent on claim 5 or 6.

9. The regenerator power source system (220) further comprises a heat exchanger (224) configured to transfer heat from the exhaust off-gas (G) to the internal volume portion of the regeneration reactor vessel (201), The return line (226, 226') is configured to transfer a part of the cooled exhaust off-gas (G) from the heat exchanger (224), The heat exchanger (224) has a heat exchanger outlet temperature (T ｈｅ ) of the exhaust off-gas (G) leaving the heat exchanger (224) that is less than 90% of the heat exchanger inlet temperature (T ｈｉ ) of the heat exchanger (224) entering the heat exchanger (224), and the system (1) according to any one of claims 1 to 8.

10. The system (1) according to any one of claims 1 to 9, further comprising a second return line (226, 226'') for transferring a part of the exhaust off-gas (G) from the internal volume portion of the regeneration reactor vessel (201) to the off-gas treatment system (600).

11. The system (1) according to any one of claims 1 to 10, further comprising a second fuel material line (228) for transferring a part of the feedstock (B) to the gas burner (221).

12. The system (1) according to any one of claims 1 to 11, wherein the gas burner (221) is configured such that when the gas entering the gas burner (221) has a temperature of less than 100°C, the temperature of the exhaust off-gas (G) ejected from the burner outlet (223) is higher than 900°C.

13. The separator (300) configured to separate the spent adsorbent (A*) from the hydrogen gas (H ２ ) ejected from the reforming reactor (100). The hydrogen gas (H ２ ) and a separator inlet (304) for supplying the used adsorbent (A*) into the separator (300), A separator (300) comprising a separator outlet (305) for ejecting the separated used adsorbent (A*). The used adsorbent (A*) and the hydrogen gas (H ２ ) a separator transfer line (150) for transferring from the reformer outlet (155) to the separator inlet (304), The system (1) according to any one of claims 1 to 12, further comprising a regenerator transfer line (320) for transferring the flow of the used adsorbent (A*) from the separator outlet (305) to the regenerator inlet (205).

14. Step A of introducing the feedstock (B) and the steam (C) into the reformer (100), wherein the reformer (100) contains a carbon dioxide capture adsorbent (A). Step B of reforming the feedstock (B) and the steam (C) in the reformer (100) to produce the reformed gas mixture and the used adsorbent (A*). Step C of transferring at least a part of the used adsorbent (A*) and at least a part of the reformed gas mixture from the reformer (100) to the regenerator (200). Step D of introducing the first burner gas (E) into the gas burner (221) at a burner inlet temperature (T ｂｉ ), wherein the gas burner (221) is configured such that the first burner gas (E) can generate exhaust off-gas (G) at a burner outlet temperature (T ｂｊ ) higher than the burner inlet temperature (T ｂｏ ), and Step D Step E of transferring the exhaust off-gas (G) from the gas burner (221) to the internal volume portion of the regeneration reactor vessel (201), wherein the gas burner (221) is configured such that the heat causes at least a portion of the carbon dioxide (CO ２ ) to be released from the used adsorbent (A*) in the regeneration reactor vessel (201) in order to at least partially regenerate the carbon dioxide capture adsorbent (A) of Step A, Step E; To cool the exhaust off-gas (G) from the burner outlet temperature (T ｂｏ ) to the regenerator inlet temperature (T ｈｉ ), at least a part (R Ｇ ) of the flow of the exhaust off-gas (G) leaving the internal volume portion of the regenerator reactor vessel (201) and heading towards the gas burner (221) is transferred in step G, and Including step H of transferring the carbon dioxide capture adsorbent (A) regenerated in step F from the regenerator (200) to the reformer (100). A method for generating hydrogen gas (H ２ ) using the system according to any one of claims 1 to 13.

15. Monitoring the flow rate (R Ａ＊ ) of the used adsorbent (A*) flowing into the regenerator inlet (205); When the variation in the flow rate (R Ａ＊ ) of the used adsorbent (A*) exceeds a predetermined flow rate threshold, in order to ensure that the burner outlet temperature (T ｂｏ ) is maintained within a predetermined temperature threshold during operation, by using an automatic controller (500) that communicates with the regenerator power source system (220) in signal communication, flowing into the internal volume portion of the regeneration reactor vessel (201), and / or adjusting the flow rate of the exhaust off-gas (G) flowing out of the internal volume portion. The method according to claim 14, further comprising the step of

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