Fluidized-bed reactor system and method

Abstract

The invention relates to a fluidized bed reactor system, comprising a gas generation reactor (1) and a calcination reactor (2), wherein the gas generation reactor (1) and the calcination reactor (2) are connected to one another by a first line (3) and a second line (4), wherein a separator device (5) is provided along the first line for separating the first intermediate flow (1-2) into a first fluidized bed material fraction (1-4) and a gas generation residue fraction (1-5), wherein the separator device (5) and the gas generation reactor (1) are connected to one another by a third line (6), and wherein a converter device (7) for gasifying the gas generation residue fraction (1-5) is provided after the separator device (5) The invention also relates to a method for producing a hydrogen-rich product gas flow (1-1) and a carbon dioxide-rich exhaust gas flow (1-6).

Description

[0001] 65127 / MB

[0002] University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT)

[0003] Friedrich-Alexander-University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0004] Fluidized bed reactor system and process

[0005] The present invention relates to a fluidized bed reactor system and a method for operating a fluidized bed reactor system. In particular, this system and this method are designed for gas production from biomass and the production of a hydrogen-rich product gas stream as well as a separate CO2-rich exhaust gas stream.

[0006] Various systems and processes for generating gas from biomass, also known as biomass gasification, are known in the state of the art. Exemplary applications for the resulting hydrogen-rich product gas range from energy supply and combined heat and power plants or fuel cells to sectors traditionally based on fossil fuels within the organic chemical, petrochemical, or metalworking industries. Provided that sustainably cultivated biomass or biogenic residues are used in the gas generation process, the product gas is also a potential raw material for the carbon-neutral production of liquid fuels, synthetic natural gas, and chemicals.

[0007] A well-known and industrially proven reactor system for the gasification of biomass to produce a non-fossil product gas is the so-called dual fluidized bed (DFB). The DFB system typically consists of a gasification reactor and a 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0008] Combustion reactor. The two reactors are operated as fluidized bed reactors, with the continuously swirled bed material ensuring homogeneous temperature fields, high heat and mass transfer rates, and thus favorable reaction conditions within the reactors. In this application, the bed material also acts as a heat transfer medium, circulating between the two reactors. Biomass is fed into the gas generation reactor, where it dries, degasses, and finally undergoes a gasification process. The gas generation residue, typically coal / coke or carbonized material, which leaves the gas generation reactor along with the bed material, is combusted in the combustion reactor.

[0009] Typical operating temperatures of such DFB plants are 800-900°C in the gas generation reactor and 900-1,000°C in the combustion reactor.

[0010] The composition of the main components of the dry product gas from such a DFB gas generation plant, whose gas generation reactor is operated with steam as the fluidization and reaction medium, is typically in the range of 35–45 vol% hydrogen, 15–30 vol% carbon monoxide, 15–25 vol% carbon dioxide, approximately 7–12 vol% methane, and 0.5–3 vol% ethene, depending on the process parameters and the composition of the feedstock. Large-scale DFB plants are known with fuel heat outputs of up to 32 MW.

[0011] Building upon the DFB gas production process, the sorption-enhanced gasification process (SEG) was developed, in which a carbonatable bed material, typically limestone, is used and the two reactors are operated under specific temperature regimes. The SEG process is also known as the SER process (sorption-enhanced reforming) or the AER process (absorption-enhanced reforming).

[0012] Compared to conventional DFB gas production, the SEG process enables the production of a hydrogen-rich product gas (especially a higher H2 / CO ratio) as well as a higher CO2 concentration in the flue gas of the 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0013] Combustion reactor. Taking into account the chemical equilibrium of CaO (carbonatable bed material) and CaCO₃ (carbonated bed material) and CO₂, CO₂ can be transferred from the gas generation reactor to the combustion reactor. In the SEG process, the combustion reactor is therefore also called a calcination reactor.

[0014] The conversion of the feedstock in the gas generation reactor in DFB plants is primarily determined by the gas generation temperature and the residence time in the reactor. These two parameters cannot be arbitrarily adjusted in the SEG process, as the temperature is limited by the chemical equilibrium between carbonatable material and carbonated material (e.g., CaO / CaCOs and CO2). Furthermore, the residence time, which depends on the circulation rate of the fluidized bed material, cannot be influenced independently of the reactor temperature. Additionally, increasing the residence time counteracts CO2 capture in the gas generation reactor due to the resulting decrease in the circulation rate of the fluidized bed material.

[0015] The gas generation temperature in SEG plants is lower than in DFB plants, typically below 750°C. This lower temperature results in slower fuel conversion in the gas generation reactor and consequently a higher quantity of gas generation residue (coal / coke) transferred to the combustion reactor. In a plant with low heat losses, this can lead to a situation where the amount of heat released in the combustion reactor exceeds the heat demand of the gas generation reactor, meaning that heat must be extracted from the system. Such a cooling requirement negatively impacts the system's exergy balance. Furthermore, within the operating limits of SEG plants, there is typically no way to adjust or increase the proportion of gasified material.

[0016] Further disadvantages of the state of the art include the following aspects:

[0017] Within the operational limits of the SEG process, there is no possibility of using an additional external heat source (e.g., electric heating) in the 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0018] To integrate a combustion reactor whose heat input can also be varied. The external heat input reduces the required amount of coke burned in the combustion reactor. To enable this, it would be necessary to continuously and controllably increase the proportion of fuel converted to product gas, independent of the SEG operating temperatures.

[0019] The CO2 content of the flue gas produced during the SEG process is high compared to conventional DFB gas production. However, the CO2 content of the flue gas could be further increased by integrating an external heat source, as described above, potentially leading to the production of pure CO2. Generally, the higher the CO2 content of a gas stream, the more energy-efficient its separation becomes.

[0020] The existing limitations of the state of the art result in the following conflict of objectives: DFB systems allow for high gas generation temperatures and, consequently, high proportions of gasified or thermochemically converted feedstock. At the same time, however, the product gas stream is comparatively low in hydrogen compared to SEG systems. The latter can be improved by using the SEG process, whereby the required lower gas generation temperatures reduce the proportion of gasified feedstock. Another advantage of the SEG process is that it directly produces a CO2-rich flue gas stream; however, this is limited by the state of the art insofar as further use, for example in Carbon Capture and Storage (CCS) or Carbon Capture and Utilization (CCU), typically requires significant effort.Moreover, the upper limit on the temperature of the gas generation reactor in the SEG process and the resulting limited fuel conversion in the gas generation reactor prevent the integration of external heat sources.

[0021] One object of the present invention can be seen as resolving this conflict of objectives, at least in part. Specifically, it can be an object of the invention to combine, at least in part, the advantages of existing DFB systems (i.e., high proportions of gasified feedstock) with those of SEG systems (i.e., hydrogen-rich product gas and high-purity CO2 stream). 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0022] Surprisingly, during high-quality scientific discussions and considerations within the framework of the present invention, it was discovered that these and other tasks can be achieved by extending known systems / processes to include further reactor components / process steps.

[0023] In particular, the invention is based on a two-reactor system comprising a first fluidized bed reactor and a second fluidized bed reactor, which are connected to each other via conduits. The connection is designed such that solid material can be transported between the reactors via the first and second conduits.

[0024] The first fluidized bed reactor can be a gas generation reactor, while the second fluidized bed reactor can be a combustion reactor. Such a combination of two fluidized bed reactors is known from existing DFB systems and is also used in SEG processes, where the fluidized bed material is typically CaO / CaCOs.

[0025] The two reactors are connected primarily via a first line and a second line. The first line can connect the lower section of the gas generation reactor to the lower section of the combustion reactor, and the second line can connect the upper section of the combustion reactor to the upper section of the gas generation reactor.

[0026] The first pipeline can be configured to transport carbonated fluidized bed material together with coal-containing gas production residue from the bottom of the gas production reactor towards the combustion reactor. This material flow can be referred to as the first intermediate flow.

[0027] It is advantageously provided that a device is arranged along the first pipeline which separates the first intermediate stream into at least two fractions, one of which is rich in fluidized bed material and the other rich in gas production residue, or coal. This can be implemented in a 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0028] Separator devices are used, which, for example, operate according to the principle of fluidized bed-based density separation.

[0029] The fraction rich in fluidized bed material (also referred to as the first fluidized bed matenal fraction) can be further fed into the combustion reactor and subjected to calcination there in a known manner. Therefore, in connection with the present disclosure, the combustion reactor is also referred to as a calcination reactor.

[0030] The fraction rich in gas production residue (also referred to as the gas production residue fraction) can be fed into a further gas production step, particularly at a higher temperature than in the gas production reactor. This gas production step can be carried out in a converter unit, thus generating a converter gas stream. The converter unit is preferably located downstream of the separator unit, with the converter gas stream being introduced into the gas production reactor via the third line. This causes the gas stream obtained during gas production in the gas production reactor and the converter gas stream to mix, forming a single product gas stream.

[0031] Any fluidized bed material transported to the converter unit with the gas production residue fraction, as well as unreacted gas production residue, can be transported from the converter unit to the gas production reactor via the third line or to the calcination reactor via another line.

[0032] By separating the solids stream and recirculating the converter gas stream, the disadvantages of the prior art described above can be at least partially overcome. In particular, this results in an increased gas production yield (through the second gas production step taking place in the converter unit), while simultaneously enabling the operation of the gas production reactor in a temperature regime that is advantageous for sorption-based gas production. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0033] The second intermediate stream exiting the calcination reactor, containing the calcined (or decarbonated) fluidized bed material produced there, is conveyed in a known manner via the second line towards the gas generation reactor. A separation device can be provided along the second line to separate the second intermediate stream into a carbon dioxide-rich exhaust gas fraction (also referred to as flue gas fraction, whereby the terms "exhaust gas" and "flue gas" can generally be used synonymously here) and a fraction rich in calcined fluidized bed material (also referred to as the second fluidized bed material fraction).

[0034] The second fluidized bed material fraction can be recycled via the second pipeline back to the gas generation reactor and subjected to another carbonation cycle. The exhaust gas fraction can be discharged or disposed of, or, in the case of CO2-rich exhaust gas, advantageously stored or utilized.

[0035] The starting material used is a carbon-containing material, such as biomass.

[0036] The gas generation reactor can be a steam gas generation reactor or it can be fluidized with steam. The gas generation reactor can be a reactor that has several reaction zones arranged in series, separated from each other by constrictions or cross-sectional narrowings.

[0037] The converter and separator equipment can also be fluidized with steam (or with the same gas as the gasification reactor). Another option is to fluidize the gas generation reactor, separator, and converter completely or partially with recycled product gas.

[0038] The fluidized bed material can, in principle, be any carbonatable material that can be subjected to a cyclic carbonation-calcination process. For example, the fluidized bed material is CaO (calcined form) / CaCOs (carbonated form), which can be used in the form of limestone. 65127 / MB

[0039] University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT)

[0040] Friedrich-Alexander-University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0041] It should be noted that the reactor and process concept described here, with the addition of a converter and / or a separator, can also be operated with a non-carbonatable fluidized bed material. In this case, the advantage of the reactor concept compared to the prior art two-bed fluidized bed system is limited to achieving a higher conversion rate of feedstock to product gas.

[0042] Typically, the gas generation reactor is operated at a temperature below 750°C, particularly when the fluidized bed material is CaO / CaCOs. If other fluidized bed materials are used, the operating temperature can be adjusted based on the chemical equilibrium between carbonated and calcined fluidized bed material.

[0043] As previously mentioned, the separator unit can yield the first fluidized bed material fraction and the gas production residue fraction. The first fluidized bed material fraction is rich in (especially carbonated) fluidized bed material, meaning that the mass fraction of fluidized bed material in this fraction is higher than in the gas stream (referred to here as the first intermediate stream) before entering the separator unit. The solids content of this fraction may also consist essentially or entirely of fluidized bed material, meaning it may only contain traces of other substances. In contrast, the gas production residue fraction is rich in gas production residue, meaning that the mass fraction of gas production residue in this fraction is higher than in the gas stream (i.e., the first intermediate stream) before entering the separator unit.If necessary, the solid content of this fraction may also consist essentially or entirely of gas production residue, meaning it may only contain residues of other substances.

[0044] The separator system can be designed as a fluidized bed separator with two separator zones, the first operating at a low flow velocity and the second at a high flow velocity. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0045] If necessary, an overflow weir can be provided in the separator to discharge the gas production residue fraction from the separator. This residue fraction typically consists of particles on the bed surface of the separator that fall over the weir. Generally, the second separator zone can be operated, for example, as a fixed-bed reactor, a fluidized-bed reactor, or a suspended-bed reactor.

[0046] The converter unit, which can be located downstream of the separator unit, is operated at a higher temperature than the gas generation reactor. The converter unit can be a steam converter or it can be fluidized with steam. The converter unit can be operated, for example, as a fixed-bed reactor, a fluidized-bed reactor, or a suspended-bed reactor. Heat may be supplied to the converter unit, for example, internally (directly) through partial combustion of the coke with partial addition of oxygen, or externally (indirectly), such as electrically.

[0047] The converter unit can be operated at a temperature that is generally higher than the operating temperature of the gas generation reactor. For example, the converter unit can be operated at a minimum of 800°C or between 800°C and 1,000°C.

[0048] The third line can return fluidized bed material to the gas generation reactor in addition to the converter gas stream, namely in particular that fluidized bed material which is contained in the gas generation residue fraction.

[0049] The converter unit can be a separate unit from the separator unit and arranged along the third line. Alternatively, the converter unit can also form part of the separator unit, in particular as a zone of a separator-converter unit. In this case, the separator zone is located upstream of the converter zone. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0050] It is noted that the terms “upstream”, “downstream” or the like are used in reference to the direction of flow of the gas and / or solid flows in the operating state of a plant described herein.

[0051] The calcination reactor can be equipped with an external heating device to provide the necessary energy. In particular, the operating temperature of the calcination reactor is above 850°C, especially when the CaO / CaCOs system is used as the fluidized bed material. Other material systems or mixtures of different materials, such as dolomite, can also be used as the fluidized bed material, in which case the advantageously used temperature regimes must be adjusted accordingly.

[0052] Advantageously, the solid material flows transported through the second and third lines can be controlled separately.

[0053] If necessary, an oxygen stream is supplied to the calcination reactor and / or the converter unit to enable complete oxidation of any remaining gas production residue.

[0054] Optionally, a fourth line is provided to transport calcined fluidized bed material from the second line to the converter unit. For this purpose, a flow divider, for example in the form of a so-called pin valve, can be provided along the second line, particularly along the section of the second line located downstream of the divider. This allows the amount of fluidized bed material introduced into the gas generation reactor to be adjusted. Simultaneously, the fluidized bed material fed into the converter unit can be used to heat the converter unit.

[0055] A fifth line may be provided to transport calcined fluidized bed material from the second line back to the calcination reactor. For this purpose, a flow divider, for example in the form of a so-called spit valve, may be provided along the second line, particularly along the section of the second line located downstream of the separation device. This allows the amount of fluidized bed material introduced into the gas generation reactor to be adjusted.

[0056] Typically, either a fourth line or a fifth line, as described here, is provided.

[0057] If necessary, a sixth line is provided to transport fluidized bed material from the converter unit to the calcination reactor.

[0058] In particular, a fluidized bed reactor system is described, comprising a gas generation reactor and a calcination reactor, wherein the gas generation reactor is set up to produce a hydrogen-rich product gas stream from a carbon-containing feedstock, for example biomass, and wherein the gas generation reactor is designed as a fluidized bed reactor containing a carbonatable fluidized bed material.

[0059] Optionally, the calcination reactor is provided for the calcination of carbonated fluidized bed material produced in the gas generation reactor to obtain a carbon dioxide-rich stream, and wherein the calcination reactor is designed as a fluidized bed reactor.

[0060] If necessary, the gas generation reactor and the calcination reactor are connected by a first line and a second line.

[0061] If applicable, the first pipeline is intended to transport a first intermediate stream from the gas generation reactor towards the calcination reactor, wherein the first intermediate stream contains carbonated fluidized bed material and gas generation residue from the gas generation reactor. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0062] If applicable, the second line is provided for the transport of a second intermediate stream from the calcination reactor towards the gas generation reactor, wherein the second intermediate stream contains carbonatable fluidized bed material.

[0063] If necessary, a separator device is provided along the first line to separate the first intermediate stream into a first fluidized bed matenal fraction and a gas production residue fraction, the separator device and the gas production reactor are connected to each other via a third line, and a converter device for gasifying the gas production residue fraction is provided downstream of the separator device.

[0064] If applicable, the carbonatable fluidized bed material is CaO, and the carbonated fluidized bed material is CaCOs.

[0065] If necessary, the separator device and the converter device are designed as separate system components, with the converter device being arranged along the third line.

[0066] Optionally, the separator device and the converter device are provided together in a separator-converter device, wherein the separator-converter device is designed as a two-zone reactor with a separator zone and a converter zone, wherein the converter zone may optionally have a larger flow cross-section than the separator zone.

[0067] If necessary, the separator device is designed as a fluidized bed density separation device, and the separator device may optionally have an overflow weir.

[0068] The gas production reactor may be provided with an outlet for the discharge of the product gas stream. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0069] If necessary, a separation device, in particular a cyclone separation device, a gravity separation device or an inertial separation device, is provided along the second line to separate the second intermediate stream into an exhaust gas fraction and a second fluidized bed material fraction.

[0070] Optionally, the separation device may have an outlet for the discharge of the exhaust gas fraction, wherein the exhaust gas fraction is in particular a carbon dioxide-rich gas fraction, preferably consisting essentially of carbon dioxide or carbon dioxide and water vapor.

[0071] If necessary, a current divider is provided along the second line, to which a fourth line connects, leading into the converter device.

[0072] If necessary, a current divider is provided along the second line, to which a fifth line connects, leading into the calcination reactor.

[0073] If necessary, a sixth line is provided, leading from the converter unit to the calcination reactor.

[0074] If necessary, an oxygen inlet for supplying an oxygen stream is provided in the calcination reactor and / or in the converter unit.

[0075] A process for producing a hydrogen-rich product gas stream from a carbon-containing starting material is also described, particularly in a fluidized bed reactor system as disclosed here.

[0076] Optionally, the carbon-containing feedstock is gasified in a gas generation reactor to obtain the hydrogen-rich product gas stream, wherein the gas generation reactor is designed as a fluidized bed reactor containing a carbonatable fluidized bed material. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0077] Optionally, it is provided that carbonated fluidized bed material produced in the gas generation reactor is calcined in a calcination reactor, thereby obtaining a carbon dioxide-rich stream, and wherein the calcination reactor is designed as a fluidized bed reactor.

[0078] If necessary, the gas generation reactor and the calcination reactor are connected by a first line and a second line.

[0079] If necessary, it is provided that a first intermediate stream is transported from the gas generation reactor towards the calcination reactor through the first line, the first intermediate stream containing carbonated fluidized bed material and gas generation residue from the gas generation reactor.

[0080] If necessary, a second intermediate stream is transported from the calcination reactor towards the gas generation reactor via the second line, the second intermediate stream containing carbonatable fluidized bed material.

[0081] If necessary, it is provided that the first intermediate stream is separated into a first fluidized bed matenal fraction and a gas production residue fraction by means of a separator device arranged along the first line, that the separator device and the gas production reactor are connected to each other via a third line, and that the gas production residue fraction is gasified by means of a converter device arranged downstream of the separator device.

[0082] If necessary, the operating temperature of the gas generation reactor is designed to be lower than the operating temperature of the converter unit. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0083] If applicable, it is provided that the operating temperature of the gas generation reactor is at most 800°C, or optionally at most 750°C, and / or that the operating temperature of the calcination reactor is at least 800°C, or optionally at least 850°C, particularly if the fluidized bed material is or comprises CaO / CaCOs.

[0084] If necessary, the gas generation reactor is provided for to be fluidized with steam and heated with fluidized bed material from the calcination reactor and / or from the converter unit.

[0085] If necessary, the gas generation reactor and / or the separator unit and / or the converter unit will be at least partially fluidized with recirculated product gas stream.

[0086] If necessary, the calcination reactor is provided for to be fluidized with water vapor and / or recirculated exhaust gas fraction and heated with external heating and / or by combustion of at least part of the gas production residue with oxygen.

[0087] If necessary, the converter equipment is provided for to be fluidized with steam and heated with external heating and / or by combustion of at least part of the gas production residue with oxygen.

[0088] If necessary, the separator device is fluidized with steam.

[0089] The gas generation reactor and / or converter unit may be designed to have a bubble-forming fluidized bed. The converter unit may be operated as a fixed-bed reactor or a moving-bed reactor. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0090] If necessary, the calcination reactor is designed to have a transporting fluidized bed.

[0091] If necessary, an oxygen stream is introduced into the calcination reactor and / or the converter unit.

[0092] Further features of the invention can be seen from the patent claims, the figures and the description of the exemplary embodiments.

[0093] The invention is explained in detail below using exemplary embodiments. These embodiments are not intended to limit the scope of protection defined by the claims, but merely to illustrate advantageous embodiments of the invention.

[0094] They show:

[0095] Fig. 1 shows a schematic representation of a fluidized bed reactor system according to a first embodiment;

[0096] Fig. 2 shows a schematic representation of a fluidized bed reactor system according to a second embodiment;

[0097] Fig. 3 shows a schematic representation of a fluidized bed reactor system according to a third embodiment;

[0098] Fig. 4 shows a schematic representation of a fluidized bed reactor system according to a fourth embodiment; and

[0099] Fig. 5 shows a schematic representation of a fluidized bed reactor system according to a fifth embodiment.

[0100] Unless otherwise specified or apparent from the context, the figures depict the following features, components, or elements: Gas generation reactor 1, Calcination reactor 2, First line 3, Second line 4, Separator unit 5, Third line 6, Converter unit 7, Outlet 8 of gas generation reactor 1, Separator unit 9, Outlet 10 of Separator unit 9, Inlet 11 of gas generation reactor 1, Flow divider 12, Fourth line 13, Flow divider 14, Fifth line 15, Separator-converter unit 16, Separator zone 17, 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0101] Converter zone 18, overflow weir 19, sixth line 20, product gas stream 1-1, first intermediate stream 1-2, second intermediate stream 1-3, first fluidized bed matenal fraction 1-4, gas production residue fraction 1-5, exhaust gas fraction 1-6, second fluidized bed matenal fraction 1-7, first steam stream 1-8, feedstock stream 1-9, second steam stream 1-10, third steam stream 1-11, secondary gas production stream 1-12.

[0102] Fig. 1 shows a schematic representation of a fluidized bed reactor system according to a first embodiment. The reactor system according to this embodiment comprises a gas generation reactor 1 and a calcination reactor 2, which are connected to each other via a first line 3 and a second line 4.

[0103] The basic structure of the reactor system according to this embodiment is as follows:

[0104] The first line 3 connects the lower section of the gas generation reactor 1 with the lower section of the calcination reactor 2, with a separator device 5 being provided along the first line 3. The second line 4 connects the upper section of the calcination reactor 2 with the upper section of the gas generation reactor 1. A separator device 9 is arranged along the second line 4.

[0105] The separator unit 5 opens into a third line 6 and a second section of the first line 3, the latter being located between the separator unit 5 and the calcination reactor 2. The third line 6 connects the separator unit 5 to the gas generation reactor 1 in its lower section, with the flow direction here, unlike in the first section of the first line 3, running from the separator unit 5 to the gas generation reactor 1.

[0106] A converter unit 7 is provided along the third line 6 before the third line 6 enters the lower section of the gas generation reactor 1. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0107] This arrangement essentially creates two solids cycles: a first solids cycle, which runs in the direction of flow as follows: Gas generation reactor 1 - first section of first line 3 - separator unit 5 - second section of first line 3 - calcination reactor 2 - second line 4 - separation unit 9 - second line 4 - gas generation reactor 1; and a second solids cycle, which runs in the direction of flow as follows: Gas generation reactor 1 - first section of first line 3 - separator unit 5 - first section of third line 6 - converter unit 7 - second section of third line 6 - gas generation reactor 1.

[0108] The reactors according to the embodiments described here can be connected to each other by connecting elements designed as non-mechanical valves, such as loop seals, L-valves, J-valves, slides or the like.

[0109] The material flows in the two material cycles described above can be controlled independently of each other, so that adjustments can be made according to the process requirements.

[0110] This reactor system can be used in a gas generation process as follows, according to the exemplary embodiment:

[0111] Limestone is used as the fluidized bed material. Gas generation reactor 1 is designed as a fluidized bed reactor, with the fluidization of the fluidized bed material being carried out by means of a first steam stream 1-8. The operating temperature of gas generation reactor 1 is below 750°C.

[0112] The biomass stream 1-9 is fed into the gas generation reactor via inlet 11, located in the lower section. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0113] In gas generation reactor 1, the material from the biomass stream 1-9 is partially gasified, resulting in solid gas generation residue and a gas mixture containing, among other things, hydrogen, carbon monoxide and carbon dioxide.

[0114] The fluidized bed material also present in gas generation reactor 1 is partially carbonated in the fluidized bed by the carbon dioxide contained in the gas mixture, resulting in the formation of CaCO₃, i.e., carbonated fluidized bed material. This generates a hydrogen-enriched product gas stream 1-1, which can be discharged via the outlet 8 located at the top of gas generation reactor 1 and used for another purpose.

[0115] The first line 3 carries away gas production residue and carbonated fluidized bed material in the form of the first intermediate stream 1-2 into the separator unit 5.

[0116] In the separator device 5, which has a lower separator section and an upper separator section, density separation of gas production residue and fluidized bed material takes place in a slightly fluidized fluidized bed, which is generated by a second steam stream 1-10.

[0117] The gas production residue, mainly coal, has a lower density than the fluidized bed material and is preferentially conveyed upwards in the flow direction, while the fluidized bed material remains in the lower separator section. The flow velocity in the upper separator section is higher than in the lower separator section, resulting in further separation of the gas production residue and the fluidized bed material. This process forms a gas production residue fraction 1-5, which is rich in gas production residue, and a first fluidized bed material fraction 1-4, which is rich in fluidized bed material.

[0118] The gas production residue fraction 1-5 is conveyed via the first section of the third

[0119] Line 6 is transferred to converter unit 7, while the first 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0120] Fluidized bed material fraction 1-4 is introduced into the calcination reactor 2 via the second section of the first line 3.

[0121] Converter unit 7 is operated as a fluidized bed reactor with a bubble-forming fluidized bed, with external heating provided, for example, by electrical energy. Fluidization in the converter unit is achieved by supplying a third steam stream 1-11. Converter unit 7 is operated at a higher temperature than the gas generation reactor, in this example at approximately 850°C. The residence time of the material is kept high to achieve the most complete possible further gas production from the material of the gas generation residue fraction 1-5.

[0122] This gas generation process produces a secondary gas generation stream 1-12 containing hydrogen, carbon monoxide, carbon dioxide and other gases.

[0123] The secondary gas generation stream 1-12 is introduced into the lower section of gas generation reactor 1 via the second section of the third line 6. It then mixes with the gas mixture generated during the gas generation process within gas generation reactor 1 itself, so that after passing through the fluidized bed material, the gases from the secondary gas generation stream 1-12 form part of the hydrogen-rich product gas stream 1-1. Calcined fluidized bed material located within gas generation reactor 1 also carbonates in the secondary gas generation stream 1-12.

[0124] The first fluidized bed material fraction 1-4 is introduced into the calcination reactor 2 via the second section of the first line 3. In the present embodiment, this reactor is operated as a fluidized bed reactor at a temperature of approximately 870°C, with the fluidized bed being a transporting fluidized bed ("Fast Fluidized Bed"). The calcination reactor 2 is externally heated and fluidized with steam and / or recirculated exhaust gas fraction 1-6 (not shown).

[0125] In calcination reactor 2, the calcination of the carbonated fluidized bed material (mainly CaCOs) from the first 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0126] Fluidized bed material fraction 1-4 to calcined or decarbonated fluidized bed material (mainly CaO) and carbon dioxide.

[0127] The second intermediate stream 1-3 thus generated is fed via the first section of the second line 4 into a separation unit 9, where it is separated into an exhaust gas fraction 1-6 and a second fluidized bed matenal fraction 1-7. The separation unit 9 is designed as a cyclone separator. The exhaust gas fraction 1-6 contains carbon dioxide, which is discharged via an outlet 10. This carbon dioxide is of high purity and can therefore be used or stored without further purification (after condensation of water vapor). The second fluidized bed matenal fraction 1-7 contains calcined fluidized bed matenal, which is introduced into the gas generation reactor via the second section of the second line 4 and subjected to a further carbonation cycle there.

[0128] It should be noted that in separator unit 5, a complete, a substantially complete, or a partial separation of fluidized bed material and gas production residue can generally take place. In other words, the first fluidized bed material fraction 1-4 may contain some proportion of gas production residue, only traces of it, or none, while the gas production residue fraction 1-5 may contain some proportion of fluidized bed material, only traces of it, or none.

[0129] In this embodiment, the process parameters were adjusted such that the gas production residue fraction 1-5 contained small amounts of fluidized bed material. This fluidized bed material is calcined in the converter unit 7 and introduced into the gas production reactor 1 as calcined fluidized bed material with the secondary gas production stream 1-12.

[0130] In this embodiment, the first fluidized bed material fraction 1-4 contains a small proportion of gas production residue. This gas production residue is mixed with the fluidized bed material in the 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0131] Calcination reactor 2 was introduced and the product was burned there and there using pure oxygen added via the fluidizing medium.

[0132] In general, it is advantageous to keep the proportions of gas production residue in the first fluidized bed material fraction 1-4 or of fluidized bed material in the gas production residue fraction 1-5 as low as possible.

[0133] In an embodiment not described in detail here, the solid material in the first fluidized bed material fraction 1-4 consists essentially of fluidized bed material (i.e., it contains only traces of gas production residue), and the solid material of the gas production residue fraction 1-5 consists essentially of gas production residue (i.e., it contains only traces of fluidized bed material). In this case, the calcination reactor 2 can be heated by an external energy supply, such as electrical energy.

[0134] Advantageously, after condensation of the contained water vapor, the exhaust gas fraction 1-6 is essentially pure CO2 and no additional CO2 separation is necessary.

[0135] Here it is advantageous if an oxygen stream can be introduced into the calcination reactor 1, with which remaining residues of gas production residue can be oxidized for process stabilization.

[0136] Fig. 2 shows a schematic representation of a fluidized bed reactor system according to a second embodiment. This largely corresponds to the first embodiment, which is why only the differences from the first embodiment are described in detail here.

[0137] Figure 2 shows that the separator unit 5 and the converter unit 7 are integrated into a separator-converter unit 16. Here, the separator unit 5 forms a separator zone 17 and the converter unit 7 a converter zone 18, the latter being located downstream of the separator zone 17. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0138] The third line 6 connects converter zone 18 and gas generation reactor 1.

[0139] In separator zone 17, the first intermediate stream 1-2, as explained in connection with the first embodiment, is separated into a first fluidized bed material fraction 1-4 and a gas production residue fraction 1-5. The gas production residue fraction 1-5 is transferred to converter zone 18, which is electrically heated to approximately 850°C, so that further gas production from the gas production residue takes place. To prevent backmixing of the two fractions, converter zone 18 can have a larger flow cross-section than separator zone 17, thereby reducing the flow velocity.

[0140] The secondary gas generation stream 1-12 obtained in converter zone 18 is fed into gas generation reactor 1 via the third line 6.

[0141] Fig. 3 shows a schematic representation of a fluidized bed reactor system according to a third embodiment. This largely corresponds to the first embodiment, which is why only the differences from the first embodiment are described in detail here.

[0142] In the second section of the second line 4, a first current divider 12 in the form of a pin valve is provided. A fourth line 13 connects to the current divider 12 and leads to the converter unit 7.

[0143] This allows the ratio of material flows fed into gas generation reactor 1 and converter unit 7 to be adjusted. The hot calcined fluidized bed material from the second fluidized bed material fraction 1-7, which can thus be partially fed into converter unit 7, is used for partial heating of converter unit 7.

[0144] Fig. 4 shows a schematic representation of a fluidized bed reactor system according to a fourth embodiment. This largely corresponds to the first. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE)

[0145] The embodiment is the same, therefore only the differences to the first embodiment are described in detail here.

[0146] In the second section of the second line 4, a flow divider 14 in the form of a spike valve is provided. A fifth line 15 connects to the flow divider 14 and leads to the calcination reactor 2.

[0147] This allows calcined fluidized bed material to be partially recycled back into calcination reactor 2, thereby optimizing the operation of calcination reactor 2 without affecting the operation of the rest of the plant.

[0148] Fig. 5 shows a schematic representation of a fluidized bed reactor system according to a fifth embodiment. This largely corresponds to the first embodiment, which is why only the differences from the first embodiment are described in detail here.

[0149] Here, the separator unit 5 is equipped with an overflow weir 19, which separates the first intermediate stream 1-2 into fluidized bed material fraction 1-4 and gas production residue fraction 1-5. Furthermore, a sixth line 20 is provided in the lower section of the converter unit 7, connecting the converter unit 7 to the lower section of the calcination reactor 2. This line is designed as a non-mechanical valve and allows the transport of fluidized bed material from the converter unit 7 into the calcination reactor.

[0150] The design of the separator device 5 with overflow weir 19 is also possible in versions where no sixth pipe 20 is provided. For example, an overflow weir 19 can also be provided in the system according to the first embodiment, but without the sixth pipe 20.

Claims

1. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE) Patent claims 1. Fluidized bed reactor system comprising a gas generation reactor (1) and a calcination reactor (2), - wherein the gas generation reactor (1 ) is set up to produce a hydrogen-rich product gas stream (1-1 ) from a carbon-containing feedstock, for example biomass, and wherein the gas generation reactor (1 ) is designed as a fluidized bed reactor containing a carbonatable fluidized bed material, - wherein the calcination reactor (2) is configured for the calcination of carbonated fluidized bed material produced in the gas generation reactor (1) to obtain a carbon dioxide-rich stream, and wherein the calcination reactor (2) is designed as a fluidized bed reactor, - wherein the gas generation reactor (1) and the calcination reactor (2) are connected to each other by a first line (3) and a second line (4), wherein the first line (3) is provided for transporting a first intermediate stream (1-2) from the gas generation reactor (1) towards the calcination reactor (2), wherein the first intermediate stream (1-2) contains carbonated fluidized bed material and gas generation residue from the gas generation reactor (1), and wherein the second line (4) is provided for transporting a second intermediate stream (1-3) from the calcination reactor (2) towards the gas generation reactor (1), wherein the second intermediate stream (1-3) contains carbonatable fluidized bed material, characterized in that a separator device (5) for separating the first intermediate stream (1-2) into a first fluidized bed material fraction (1-4) and a gas production residue fraction (1-5) are provided,that the separator device (5) and the gas generation reactor (1) are connected to each other via a third line (6), and that subsequently to the, 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE) The separator unit (5) includes a converter unit (7) for gasifying the gas production residue fraction (1-5).

2. Fluidized bed reactor system according to claim 1, characterized in that the carbonatable fluidized bed material is CaO, and that the carbonated fluidized bed material is CaCOs.

3. Fluidized bed reactor system according to claim 1 or 2, characterized in that, - that the separator device (5) and the converter device (7) are designed as separate system components, wherein the converter device (7) is arranged along the third line (6), - or that the separator device (5) and the converter device (7) are jointly provided in a separator-converter device, wherein the separator-converter device (16) is designed as a two-zone reactor with a separator zone (17) and a converter zone (18), wherein the converter zone (18) may optionally have a larger flow cross-section than the separator zone (17).

4. Fluidized bed reactor system according to one of claims 1 to 3, characterized in that the separator device (5) is designed as a fluidized bed density separation device, wherein the separator device (5) optionally has an overflow weir.

5. Fluidized bed reactor system according to one of claims 1 to 4, characterized in that the gas generation reactor (1 ) has an outlet (8) for the discharge of the product gas stream (1-1 ).

6. Fluidized bed reactor system according to one of claims 1 to 5, characterized in that a separation device (9), in particular a cyclone separation device, a gravity separation device or an inertial separation device, is provided along the second line (4) for separating the second intermediate stream (1-3) into a carbon dioxide-rich 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE) exhaust gas fraction (1-6) and a second fluidized bed material fraction (1-7) are provided.

7. Fluidized bed reactor system according to claim 6, characterized in that the separation device (9) has an outlet (10) for the discharge of the exhaust gas fraction (1-6), wherein the exhaust gas fraction (1-6) is in particular a carbon dioxide-rich gas fraction, preferably consisting essentially of carbon dioxide or carbon dioxide and water vapor.

8. Fluidized bed reactor system according to one of claims 1 to 7, characterized in that a current divider (12) is provided along the second line (4), to which a fourth line (13) is connected, which leads into the converter device (7).

9. Fluidized bed reactor system according to one of claims 1 to 8, characterized in that a current divider (14) is provided along the second line (4), to which a fifth line (15) is connected, which leads into the calcination reactor (2).

10. Fluidized bed reactor system according to one of claims 1 to 9, characterized in that optionally a sixth line (20) is provided which leads from the converter device (7) to the calcination reactor (2).

11. Fluidized bed reactor system according to one of claims 1 to 10, characterized in that an oxygen inlet for supplying an oxygen stream is provided in the calcination reactor (2) and / or in the converter device (7).

12. Method for producing a hydrogen-rich product gas stream (1-1) from a carbon-containing starting material, in particular in a fluidized bed reactor system according to one of claims 1 to 11 , - wherein the carbon-containing feedstock is gasified in a gas generation reactor (1 ) and thereby the hydrogen-rich 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE) product gas stream (1-1 ) is obtained, and wherein the gas generation reactor (1 ) is designed as a fluidized bed reactor containing a carbonatable fluidized bed material, - wherein carbonated fluidized bed material produced in the gas generation reactor (1) is calcined in a calcination reactor (2), thereby obtaining a carbon dioxide-rich stream, and wherein the calcination reactor (2) is designed as a fluidized bed reactor, - wherein the gas generation reactor (1) and the calcination reactor (2) are connected to each other by a first line (3) and a second line (4), wherein a first intermediate stream (1-2) is transported from the gas generation reactor (1) towards the calcination reactor (2) through the first line (3), wherein the first intermediate stream (1-2) contains carbonated fluidized bed material and gas generation residue from the gas generation reactor (1), and wherein a second intermediate stream (1-3) is transported from the calcination reactor (2) towards the gas generation reactor (1) through the second line (4), wherein the second intermediate stream (1-3) contains carbonatable fluidized bed material, characterized in that the first intermediate stream (1-2) is separated into a first fluidized bed material fraction (1-4) by a separator device (5) arranged along the first line (3) and a gas production residue fraction (1-5) is separated,that the separator device (5) and the gas generation reactor (1) are connected to each other via a third line (6), and that the gas generation residue fraction (1-5) is gasified by a converter device (7) arranged downstream of the separator device (5).

13. Method according to claim 12, characterized in that the operating temperature of the gas generation reactor (1 ) is lower than the operating temperature of the converter device (7).

14. Method according to claim 12 or 13, characterized in that the operating temperature of the gas generation reactor (1) is at most 800°C, in particular at most 750°C, and / or that the operating temperature 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 VIENNA (AT) Friedrich-Alexander-University Erlangen-Nuremberg, Schlossplatz 4, 91054 ERLANGEN (DE) of the calcination reactor (2) is at least 800°C, in particular at least 850°C, especially if the fluidized bed material is or comprises CaO / CaCOs.

15. Method according to one of claims 12 to 14, characterized in that, - that the gas generation reactor (1 ) is fluidized with steam and heated with fluidized bed material from the calcination reactor (2) and / or from the converter unit (7), and / or, - that the gas generation reactor (1 ) and / or the separator unit (5) and / or the converter unit (7) is / are at least partially fluidized with recirculated product gas stream (1 -1 ), and / or, - that the calcination reactor (2) is fluidized with water vapor and / or recirculated exhaust gas fraction (1-6) and heated with external heating and / or by combustion of at least part of the gas production residue with oxygen, and / or, - that the converter device (7) is fluidized with steam and heated by external heating and / or by combustion of at least part of the gas production residue with oxygen, and / or, - that the separator device (5) is fluidized with steam.

16. Method according to one of claims 12 to 15, characterized in that the gas generation reactor (1 ) and / or the converter device (7) have a bubble-forming fluidized bed.

17. Method according to one of claims 12 to 16, characterized in that the calcination reactor (2) has a transporting fluidized bed. 65127 / MB University of Natural Resources and Life Sciences Vienna, Gregor-Mendel-Straße 33, 1180 Vienna (AT) Friedrich-Alexander University Erlangen-Nuremberg, Schlossplatz 4, 91054 Erlangen (DE) 18. Method according to one of claims 12 to 17, characterized in that an oxygen stream is introduced into the calcination reactor (2) and / or into the converter device (7).

19. Method according to one of claims 12 to 18, characterized in that an exhaust gas fraction (1-6) is separated from the second intermediate stream (1-3) in a separation device (9), which consists essentially of carbon dioxide or of carbon dioxide and water vapor.

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