CO shift device for converting solid waste into synthesis gas

Abstract

The CO shift unit 500 as part of a plant 1 for converting solid waste to a product gas stream containing hydrogen allows low temperature thermal energy in the low temperature heat recovery unit 524 to be used in an energy efficient manner to heat the treated water stream used in the plant 1.

Description

Technical Field

[0001] The subject matter of the present invention is a method for converting solid waste into synthesis gas using a CO shift device and a plant corresponding to this method.

Background Art

[0002] Municipal Solid Waste (MSW) occurs worldwide and there is a need to address it. In the Western Hemisphere, MSW is either landfilled or incinerated. In contrast to recycling or reusing the contents of MSW at the molecular scale such as chemical recycling, incineration focuses on maximizing the energy content of MSW. Incineration causes problems related to the emission of pollutants into the atmosphere, and as a result, depending on national or regional regulations, significant technical efforts are required to meet the restrictions imposed by national / regional regulations. Furthermore, due to the products generated by incineration such as fly ash, bottom ash, gypsum and heavy metals, activated carbon containing dioxins, etc., there are further challenges in further using or treating these. Furthermore, the power generation efficiency of waste, that is, the amount of calorie value transferred to thermal energy is small, usually in the range of 20 to 25%.

[0003] When chemical recycling is desired, it is often necessary to improve the yield, i.e., the final outcome of the usable chemicals, or to ensure adequate energy efficiency. In many cases, gases containing carbon monoxide and hydrogen are generated, for example, by pyrolysis. To increase the amount of hydrogen in the product stream, a CO shift reaction can be used, for example, as known in Patent Document 1. To optimize hydrogen production, it is necessary to supply a considerable surplus of water vapor, which results in a large amount of water being generated in the product gas of the CO shift reaction. When this product gas is cooled, a considerable amount of condensation occurs, cooling the product gas to ambient temperature while a large amount of low-level heat is introduced into the cooling train. Normally, most of this energy is wasted, resulting in low energy efficiency. Therefore, the object of the present invention is to overcome the shortcomings of the prior art in this respect.

[0004] This objective is addressed by the features of the independent claim. The dependent claims relate to preferred embodiments of the present invention. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] U.S. Patent Application Publication No. 2009 / 0077892 Specification [Overview of the Initiative] [Means for solving the problem]

[0006] According to the present invention, a method for increasing the hydrogen content in a product gas stream by semi-carbonization of solid recovered fuel (SRF) pellets is used. This method involves supplying a synthesis gas stream containing semi-carbonized synthesis gas to a CO shift device, which generates semi-carbonized synthesis gas that is converted into semi-carbonized synthesis gas containing hydrogen and carbon monoxide. The solid recovered fuel pellets are semi-carbonized into carbonized pellets, and at least a portion of the carbon monoxide is reacted with water vapor to produce carbon dioxide and hydrogen. This generates shift synthesis gas, which is then supplied to a low-temperature heat recovery device downstream of the CO shift device. In the low-temperature heat recovery device, the shift synthesis gas is guided through at least two heat exchangers, where it exchanges heat with the aforementioned at least two water streams to heat them. The water streams are then used downstream of each heat exchanger as treated water for generating the product gas stream.

[0007] Throughout this specification, the term "synthesis gas" is understood to mean a gas containing at least one of hydrogen, carbon monoxide, and carbon dioxide. Solid recovery fuel pellets are derived from solid waste, including municipal waste. The term "partial carbonization" is understood to mean the quasi-stoichiometric oxidation of solid recovery fuel pellets to generate untreated synthesis gas containing hydrogen and carbon monoxide. The resulting carbonized pellets are preferably gasified in a gasifier to produce synthesis gas. For example, the partial carbonized synthesis gas containing hydrogen and carbon monoxide, generated by the thermal decomposition of the partial carbonized gas produced during the partial carbonization of solid recovery fuel pellets, is preferably supplied to a CO shift device in combination with the synthesis gas produced during the gasification process. The CO shift device is preferably a two-stage CO shift device consisting of a high-temperature CO shift device and a low-temperature CO shift device, and is used to support the carbon monoxide (CO) shift reaction in which carbon monoxide and water vapor react to produce carbon dioxide and hydrogen.

[0008] Downstream of the CO shifting unit, the resulting shifted synthesis gas has a temperature above the required ambient temperature by adjusting the chemical equilibrium within the CO shifting unit. For example, in a two-stage CO shifting unit, the synthesis gas enters the high-temperature CO shifting reactor at approximately 270°C and leaves the low-temperature CO shifting reactor at approximately 240°C. Therefore, the shifted synthesis gas needs to be cooled so that it can then be stored or processed, i.e., used as a raw material or energy storage medium, or supplied to a gas purification unit that separates hydrogen from the remaining shifted synthesis gas that is purged as a purge gas. As the shifted synthesis gas is being cooled, any water vapor still present in the shifted synthesis gas condenses as soon as the temperature falls below the dew point. A considerable amount of thermal energy is then released in the form of condensation energy.

[0009] According to the present invention, the thermal energy contained in the shift synthesis gas before it enters the low-temperature heat recovery device is not discarded into the surroundings by an air cooler or water cooler, etc., but is used to heat at least two treatment water streams used to generate the product gas. These at least two product water streams are preferably in a liquid state, a gaseous state, or both, i.e., liquid water, water vapor, or both.

[0010] Each generated water stream is a treated water stream used, for example, to increase the steam content of semi-carbonized synthesis gas or another synthesis gas before it enters the CO shift unit. Alternatively or in addition to this, it is preferable to use the treated water stream when gasifying the carbonized pellets in the gasifier to perform jet-bed gasification of the carbonized pellets. Alternatively or in addition to this, boiler feedwater for generating high-pressure steam is heated. Preferably, the generation of this high-pressure steam is maximized at the expense of the generation of low-pressure steam. Throughout this specification, the term high-pressure steam is understood to consist of pressures in the range of 80 bar to 140 bar, while low-pressure steam is understood throughout this specification to consist of pressures in the range of about 3 bar to 12 bar. Throughout this specification, the term medium-pressure is understood to consist of pressures in the range of about 18 bar to 43 bar.

[0011] According to a preferred embodiment, the shift synthesis gas is supplied to a gas purification device that generates a hydrogen-rich product gas stream while generating a purge gas, and the hydrogen-rich product gas stream preferably has a hydrogen content of 99.5% by volume or more. Both the purge gas and the semi-carbonized synthesis gas are compressed and introduced together into the saturation tower, increasing the moisture content in the synthesis gas stream upstream of the CO shift unit.

[0012] This makes it possible to easily adjust the moisture content of the synthesis gas supplied to the CO shift unit. Mixing the purge gas with semi-carbonized synthesis gas ensures that carbon monoxide, hydrogen, or both that may be present in the purge gas are not released.

[0013] According to one embodiment, the first synthesis gas stream generated by the gasification of carbonized pellets is supplied to a high-pressure cleaning device to increase the moisture content in the purified synthesis gas stream.

[0014] By using a high-pressure cleaning device, it is possible to reduce contaminants such as long-chain carbon-hydrogen compounds in the first synthesis gas stream, and at the same time, to introduce moisture into the purified synthesis gas stream, thereby enabling precise adjustment of the moisture content of the gas stream entering the CO shift device.

[0015] According to one embodiment, the shift synthesis gas is cooled in a low-temperature heat recovery device by thermal contact with at least one of the following water flows: a) a treated water flow used to humidify the synthesis gas flow entering the CO shift device. b) Feed water for gasifying carbonized pellets, especially for rapid cooling. c) Boiler water for generating high-pressure steam

[0016] In particular, when step c) and at least one of steps a) and b) are implemented similarly, the process is controlled to improve the overall energy yield of the process, which generates a hydrogen-containing product gas stream from the solid recovery fuel pellets, by prioritizing the generation of high-pressure steam. Preferably, each water stream passes through at least one heat exchanger arranged so as to make the most efficient use of the thermal energy content of the shift synthesis gas.

[0017] According to one embodiment, the pressure of the treated water in the heat exchanger of the low-temperature heat recovery system is higher than the pressure of the shift synthesis gas. This ensures that even if there is leakage in each heat exchanger, the synthesis gas will not enter each water flow.

[0018] According to a further aspect of the present invention, a plant is proposed for converting solid waste supplied as solid recovery fuel pellets into a hydrogen-rich generated gas stream. This plant is A semi-carbonization apparatus capable of supplying solid recovered fuel pellets and producing semi-carbonized gas and carbonized pellets, A semi-carbonized gas treatment device that converts semi-carbonized gas into semi-carbonized synthesis gas, A CO shift device located downstream of a semi-carbonization plant, capable of supplying a mixed synthesis gas flow containing at least semi-carbonization synthesis gas, and capable of generating shift synthesis gas, A low-temperature heat recovery device located downstream of a CO shift device, wherein shift synthesis gas can be supplied to the low-temperature heat recovery device, the low-temperature heat recovery device has at least two heat exchangers, and the shift synthesis gas and the treated water flow can be supplied to each heat exchanger in order to raise the temperature of the treated water flow.

[0019] This makes it possible to efficiently use the low-temperature heat in the shift synthesis gas to heat the treated water stream used to generate the product gas stream from the solid recovery fuel pellets. The plant components according to the present invention are preferably suitable for and intended to carry out the method according to the present invention.

[0020] According to one embodiment, the low-temperature heat recovery device has at least two of the following heat exchangers. a) A second heat exchanger capable of heating water, especially water used in a gasification device, with shift synthesis gas b) A third heat exchanger capable of heating water for generating high-pressure steam with shift synthesis gas c) A fourth heat exchanger which is a saturation tower upstream of a CO shift device and is capable of heating water used in the saturation tower for adjusting at least the moisture content of semi-carbonized synthesis gas with shift synthesis gas d) A fifth heat exchanger capable of heating water for generating high-pressure steam with shift synthesis gas e) A sixth heat exchanger preferably capable of heating water used in a gasification device with shift synthesis gas

[0021] Two or more of the second to sixth heat exchangers are arranged in the order of their numbers, and accordingly, the temperature level of the shift synthesis gas decreases. For example, the temperature of the shift synthesis gas entering the first heat exchanger is higher than the temperature of the shift synthesis gas entering the third heat exchanger or the like. Thereby, it becomes possible to efficiently use the thermal energy of the shift synthesis gas while cooling the shift synthesis gas.

[0022] According to one embodiment, the plant further includes a saturation tower capable of adjusting at least the moisture content of semi-carbonized synthesis gas. The saturation tower is preferably a normal wet scrubber, in which water is supplied to the top of the tower and taken out from the water collection holes of the tower while each gas flow flows against the direction of the water flow. Preferably, the plant includes a gas purification device downstream of the low-temperature heat recovery device, in which hydrogen is separated by a pressure swing adsorption device to generate a purge gas. The purge gas is combined with the semi-carbonized synthesis gas and supplied to the saturation tower.

[0023] In addition, the individual features specified in the claims can be combined with each other in any desired technically significant manner, and further embodiments of the present invention can be defined. The present invention will be further described herein, particularly with reference to the figures, and particularly preferred embodiments of the present invention are disclosed. Particularly preferred variations and technical fields of the present invention will be described in more detail below with reference to the accompanying figures. Note that the exemplary embodiments shown in the figures are not intended to limit the present invention. The figures are schematic and may not be drawn to scale.

Brief Description of the Drawings

[0024] [Figure 1] A plant for converting solid waste into a hydrogen-containing gas, which has a carbon monoxide shift device, is shown. [Figure 2] A carbon monoxide shift device is shown.

Embodiments for Carrying Out the Invention

[0025] FIG. 1 schematically shows a plant 1 for converting solid waste into a hydrogen-containing gas, and this plant 1 has a carbon monoxide (CO) shift device 500. In the CO shift device 500, a carbon monoxide (CO) shift reaction is carried out in which carbon monoxide (CO) reacts with water (H2O) to become carbon dioxide (CO2) and hydrogen (H2) as follows. CO + H2O ⇔CO2+ H2

[0026] This reaction is in chemical equilibrium and can be influenced in either the extractor or product direction by conventional methods, for example, by using different temperatures and specific catalyst concentrations. Since the reaction is endothermic, water is usually supplied as steam. To shift the chemical equilibrium towards the product side and increase hydrogen production, it has been found that a steam-to-carbon monoxide molar ratio of about 2.3 to 2.7, particularly about 2.5, is advantageous. The steam is preferably supplied at a pressure higher than the pressure at which the shift reaction occurs, preferably about 40 bar. When the steam-to-carbon monoxide molar ratio is 2.5, 1.5 moles of excess steam remain in the reactor for every mole of carbon dioxide. As a result, a large amount of water is produced in the CO shift reaction product gas. When this product gas is cooled, a considerable amount of condensation occurs, cooling the product gas to ambient temperature while a large amount of low-level heat is introduced into the cooling path. Normally, most of this energy is wasted, resulting in low energy efficiency.

[0027] The CO shift unit 500 is part of Plant 1 for converting solid waste into hydrogen-containing gases, particularly hydrogen and hydrogen-containing synthesis gas. After solid recovery fuel pellets are produced in the pelletizing unit 100 from solid waste such as municipal waste 103, preferably solid waste further supplemented with biomass, each solid recovery fuel pellet 117 is transported to Plant 1 and supplied to the semi-carbonization unit 200, where the pellets are semi-carbonized, i.e., quasi-stoichiometrically oxidized at a temperature of 250°C to 300°C. The term semi-carbonization is understood as thermochemical treatment of the solid recovery fuel pellets at a temperature of 250°C to 320°C. Semi-carbonization is carried out under atmospheric pressure and without the addition of oxygen, for example, without supplying air. During the semi-carbonization process, water contained in the solid recovery fuel pellets evaporates, as do volatile components contained in the solid recovery fuel pellets. The biopolymers contained in the solid recovery fuel pellets are partially decomposed as volatile substances are released. The products of the semi-carbonization process are carbonized pellets and semi-carbonized gas. When pellets are semi-carbonized, carbonized pellets 201 are obtained, and these pellets are gasified in the gasifier 300. Another product of semi-carbonization is semi-carbonized gas 202, which is supplied to the semi-carbonized gas treatment device 400. The product of the semi-carbonized gas treatment device 400 is semi-carbonized synthesis gas 401, while the product of the gasifier 300 is synthesis gas 301. Both semi-carbonized synthesis gas 401 and untreated synthesis gas 301 contain water vapor, carbon monoxide, and hydrogen. Both synthesis gases 301 and 401 are introduced into the CO shift device 500. The CO shift device 500 will be described in detail later with reference to Figure 2. The shifted synthesis gas 501 generated in the CO shift device 500 is transferred to a gas purification device 600 that separates hydrogen 601 from purge gas 602. Preferably, the pelletizing equipment 100 is located outside, i.e., not in the same location as the plant 1 for converting solid waste into hydrogen-containing gas.

[0028] Figure 2 shows the CO shift device 500. The first synthesis gas stream 301 generated by the gasifier 300 is introduced into the high-pressure scrubbing device 502. The high-pressure scrubbing device 502 is a conventional wet scrubber device, in which higher hydrocarbons, for example, are removed from the synthesis gas 301. The high-pressure scrubbing device 502 is supplied with feed water 503, which is condensed water 508 from low-temperature heat recovery, described later. The water 505 collected in the water collection holes 504 of the high-pressure scrubbing device 502 is sent to the bleed water conduit 507 by the transport means 506. The purified synthesis gas 509 generated in the high-pressure scrubbing device 502 is supplied to the first heat exchanger 518 downstream of the high-pressure scrubbing device 502. The term "transporting means" in this specification is understood to mean a pump, a compressor, or both. The high-pressure cleaning device 502 can clean the first synthesis gas stream 301 while simultaneously controlling the moisture content of the purified synthesis gas 509.

[0029] The synthesis gas 401 produced in the semi-carbonized gas treatment device 400 is sent to the saturation tower 510 by the conveying means 511. The conveying means 511 compresses the synthesis gas 401, preferably to a pressure of 40 bar. The conveying means 511 may include a plurality of compressors having intercoolers, thereby performing multi-stage intercooling compression on the synthesis gas 401. Similarly, the purge gas 602 from the gas purification device 600 is also sent to the saturation tower 510 by the conveying means 512. The conveying means 512 compresses the purge gas 602, preferably to a pressure of 40 bar. The conveying means 512 may include a plurality of compressors having intercoolers, thereby performing multi-stage intercooling compression on the purge gas 602. The saturation tower 510 is a conventional wet scrubber, and treated water 513 is supplied from a low-temperature heat recovery device 524 (described later) via the conveying means 514. The water 515 collected in the water collection holes 516 of the saturation tower 510 is used as treated water in the low-temperature heat recovery device 524, which will be described later. The saturation tower 510 mixes the synthesis gas 401 and the purge gas 602, and at the same time, water is added to the resulting saturated tower product gas 517. The water content of the saturated tower product gas 517 can be controlled according to the parameters that operate the saturation tower, i.e., the water flow and water temperature.

[0030] The saturated tower product gas 517 is supplied to the first heat exchanger 518 together with the purified synthesis gas 509. In the first heat exchanger 518, energy is transferred from the high-temperature CO shift reactor exhaust gas 519 to the purified synthesis gas 509 and the saturated tower product gas 517, and these gases are mixed downstream of the first heat exchanger 519 to form a mixed synthesis gas flow 520. The heat exchange in the first heat exchanger 518 cools each of the high-temperature CO shift reactor exhaust gases 519 while heating the purified synthesis gas 509 and the purified gas flow 517. Preferably, the saturated tower 510 is operated so that the mixed synthesis gas flow 520 has a molar ratio of water vapor to carbon monoxide of 2.0 to 3.0, preferably 2.4 to 2.6, and especially about 2.5.

[0031] The mixed synthesis gas flow 520 is supplied downstream of the first heat exchanger 518 to the high-temperature CO shift reactor 521 where the shift reaction described above takes place. Compared to the mixed synthesis gas flow 520, the high-temperature CO shift reactor exhaust gas 519 has a reduced water / steam and carbon monoxide content and an increased hydrogen (H2) content. The high-temperature CO shift reactor exhaust gas 519 is guided to the low-temperature CO shift reactor 522 through a series of heat exchangers, including the first heat exchanger 518, to lower its temperature, as described below, where the CO shift reaction described above takes place. Compared to the high-temperature CO shift reactor exhaust gas 519 entering the low-temperature CO shift reactor 522, the low-temperature CO shift reactor exhaust gas 523 has a higher hydrogen (H2) content.

[0032] The low-temperature CO shift reactor exhaust gas 523 is guided downstream of the low-temperature CO shift reactor 522 through a low-temperature heat recovery unit 524. In this low-temperature heat recovery unit 524, the heat contained in the low-temperature CO shift reactor exhaust gas 523 is used to raise the temperature of several water flows. After entering the low-temperature CO shift reactor exhaust gas 523, it is then guided through a second heat exchanger 525, a third heat exchanger 526, a fourth heat exchanger 527, a fifth heat exchanger 528, and a sixth heat exchanger 529. As it passes through these heat exchangers 524, 525, 526, 527, 528, and 529, the temperature of the low-temperature CO shift reactor exhaust gas 523 gradually decreases, and it then leaves the low-temperature heat recovery unit 524 as a synthesis gas flow 530, passing through an air cooler 531 if and if necessary. Subsequently, this synthesis gas stream 530 is supplied to the gas purification device 600 as described above.

[0033] In the first second heat exchanger 525, the heat contained in the synthesis gas flow 530 is used to heat the feedwater 508 used in the gasifier 300. Thus, for example, this water 508 can be heated to 158°C to 205°C. In the second third heat exchanger 526, water that can be used to generate high-pressure steam is heated. The water is heated to, for example, typically 155°C to 200°C. In the third fourth heat exchanger 527, the treated water 513 is heated to typically 135°C to 158°C and used in the saturation tower 510. This water can be further used as feedwater 508, especially as feedwater 508 after passing through the second heat exchanger 525. In the fourth heat exchanger 527, the low-temperature CO shift reactor exhaust gas 523 is cooled below the dew point, so that a large amount of condensation heat is released and used for heat transfer. In the fourth fifth heat exchanger 528, boiler feedwater 536 is typically heated to 35°C to 155°C and is preferably used to generate high-pressure steam. In the fifth sixth heat exchanger 529, water is typically heated to 25°C to 135°C for use in gasifying carbonized pellets 201 in the gasifier 300.

[0034] The feedwater 508 for the gasification unit 300 is, as described above, at least a portion of the water 515 recovered in the collection port 519 of the saturation tower 510. The water 515 recovered in the collection port 516 of the saturation tower 510 enters the fourth heat exchanger 527. Water 521 from a wastewater treatment device (not shown) may be mixed with the water 515 after passing through the sixth heat exchanger 529. Downstream of the second heat exchanger 527, the wastewater flow 533 from the heated fourth heat exchanger is guided, partly to be used as treated water 513 from low-temperature heat recovery in the saturation tower 510, partly to pass through the second heat exchanger 525, downstream of the second heat exchanger 525, partly as condensed water 508, partly as feedwater 503 for the high-pressure cleaning device 502, and partly as treated water for the semi-carbonization unit 200. Further portions of the water downstream of the sixth heat exchanger 529 are used, for example, as condensate 534 supplied to a water stripper. Other water, such as external high-pressure boiler feedwater 535 generated for external uses of Plant 1, is guided through the fifth heat exchanger 528 and is partially used as boiler feedwater 536 for, for example, the gasifier 300, low-pressure steam generators, and semi-carbonizers 200. Another portion of the boiler feedwater 535 is guided downstream of the fifth heat exchanger 528 through the second heat exchanger 526. It then passes through the seventh heat exchanger 537.

[0035] The CO shift device 500, as part of Plant 1 for converting solid waste into a hydrogen-containing generated gas stream, enables the energy-efficient use of low-temperature thermal energy in the low-temperature heat recovery device 524 to heat the treated water stream used in Plant 1. [Explanation of Symbols]

[0036] 1. Plant for converting solid waste 100 Pelletization Equipment 103 Municipal waste 117 pellets 200 Torrefaction device 201 Carbonized Pellets 202 Semi-carbonized gas 300 Gasification equipment 301 Synthesis Gas 400 Semi-carbonized gas treatment device 401 Semi-carbonized synthesis gas 500 CO shift device 501 Shift Synthetic Gas 502 High-pressure cleaning equipment 503 Supply water 504 Water collection hole 505 Water 506 Conveying means 507 Bleed water conduit 508 Condensate 509 Purified Synthetic Gas 510 Saturation Tower 511 Conveying means 512 Conveying means 513 Treated water from low-temperature heat recovery 514 Conveying means 515 Water 516 Water collection hole 517 Saturated tower generated gas 518 First heat exchanger 519 High-temperature CO shift reactor exhaust gas 520 Mixed high-temperature synthesis gas flow 521 High-temperature CO shift reactor 522 Low-temperature CO shift reactor 523 Low-temperature CO shift reactor exhaust gas 524 Low-temperature heat recovery system 525 Second heat exchanger 526 Third heat exchanger 527 The fourth heat exchanger 528 Fifth heat exchanger 529 The sixth heat exchanger 530 Synthesis gas flow 531 Air cooler 532 water 533 Drainage flow of the fourth heat exchanger 534 Condensation 535 High-pressure boiler feedwater 536 Boiler feedwater 537 The seventh heat exchanger 538 Saturated tower generated gas 600 Gas purification device 601 Hydrogen-rich product gases 602 Purge gas

Claims

1. A method for increasing the hydrogen content in the gas stream produced by the semi-carbonization of solid recovered fuel pellets (117), While generating semi-carbonized gas (202) which is converted by thermal decomposition in a semi-carbonized gas treatment device from semi-carbonized synthesis gas (401) containing hydrogen and carbon monoxide, the solid recovered fuel pellets (117) are semi-carbonized into carbonized pellets (201). A CO shift device (500) that reacts at least a portion of carbon monoxide with water vapor to produce carbon dioxide and hydrogen is supplied with a synthesis gas stream containing at least the semi-carbonized synthesis gas (401), thereby generating a shift synthesis gas (501). The shift synthesis gases (501, 523) are supplied to the low-temperature heat recovery device (524) downstream of the CO shift device (500). In the low-temperature heat recovery device (524), the shift synthesis gas (501, 523) is guided through at least two heat exchangers (525, 526, 527, 528, 529), In the heat exchangers (525, 526, 527, 528, 529), the shift synthesis gas (523, 501) is cooled by thermal contact with at least two water streams in order to heat at least two water streams. The aforementioned water flow is used as treated water when generating the generated gas flow downstream of each of the heat exchangers (525, 526, 527, 528, 529). The treated water is at least one of the following: a) treated water stream used to humidify the synthesis gas stream (509) entering the CO shift device; b) feed water used for rapid cooling in the gasification of the carbonized pellets (201); c) boiler water for generating high-pressure steam. The shift synthesis gases (530, 501) are then supplied to a gas purification device (600) that generates a hydrogen-rich product gas stream (601) while simultaneously generating a purge gas (602). The hydrogen-rich generated gas stream (601) preferably has a hydrogen content of 99.5% by volume or more. method.

2. The method according to claim 1, Both the purge gas (602) and the semi-carbonized synthesis gas (401) are compressed and introduced together into the saturation tower (510) to increase the moisture content in the synthesis gas stream (520) upstream of the CO shift device (500). method.

3. A method according to claim 1 or 2, The first synthesis gas stream (301) generated by the gasification of the carbonized pellets (201) is supplied to a high-pressure cleaning device (502) to increase the water content in the purified synthesis gas stream (509). method.

4. A method according to any one of claims 1 to 3, In the heat exchangers (525, 526, 527, 528, 529) of the low-temperature heat recovery device (524), the pressure of the treated water is higher than the pressure of the shift synthesis gas (523). method.

5. A plant (1) for converting solid waste supplied as solid recovery fuel pellets (117) into a hydrogen-rich generated gas stream (601), A semi-carbonization device (200) capable of supplying the solid recovered fuel pellets (117) and producing semi-carbonized gas (202) and carbonized pellets (201), A semi-carbonized gas treatment apparatus (400) configured to convert the semi-carbonized gas (202) into semi-carbonized synthesis gas (401) by thermal decomposition, A CO shift device (500) located downstream of the semi-carbonization device (200), A mixed synthesis gas stream (520) containing at least the semi-carbonized synthesis gas (401) can be supplied to the CO shift device (500). A CO shift device (500) capable of generating shift synthesis gases (523, 530, 501), A low-temperature heat recovery device (524) located downstream of the CO shift device (500), The shift synthesis gas (523, 501) can be supplied to the low-temperature heat recovery device (524), The low-temperature heat recovery device (524) has at least two heat exchangers (525, 526, 527, 528, 529), In order to raise the temperature of the treated water flow, the shift synthesis gas (523, 501) and the treated water flow can be supplied to the heat exchangers (525, 526, 527, 528, 529), The heated water flow is structurally arranged to be used as treated water when generating the generated gas flow (601) downstream of the heat exchangers (525, 526, 527, 528, 529). The system includes a low-temperature heat recovery device (524), The plant further comprises at least one of the following: a) a saturated tower (510), b) a gasifier (300), and c) a boiler. The plant is configured to supply the water flow heated in the heat exchangers (525, 526, 527, 528, 529) to at least one of the saturation tower (510), the gasifier, and the boiler for use as treated water. Furthermore, the system includes a gas cleaning unit (600) configured to receive the shift synthesis gas (530, 501) from the low-temperature heat recovery device (524) and generate the generated gas flow (601) while generating a purge gas (602). plant.

6. The plant (1) according to claim 5, In the saturated tower (510), the moisture content of at least the semi-carbonized synthesis gas (401) can be adjusted. plant.

7. The plant (1) according to claim 5 or 6, The low-temperature heat recovery device (524) is the heat exchanger (525, 526, 527, 528, 529) described below. a) A second heat exchanger (525) that can heat the water supplied to a gasifier (300) capable of gasifying the carbonized pellets (201) with the shift synthesis gas (523, 501), b) A third heat exchanger (526) capable of heating water for generating high-pressure steam with the shift synthesis gas, c) A saturation tower (510) located upstream of the CO shift device (500), comprising a fourth heat exchanger (527) capable of heating the water used in the saturation tower (510) for adjusting the moisture content of the semi-carbonized synthesis gas with the shift synthesis gas (523, 501), d) A fifth heat exchanger (528) capable of heating water for generating high-pressure steam with the shift synthesis gas (523, 501), e) A sixth heat exchanger (529) that can heat the water used in the gasifier (300) capable of gasifying the carbonized pellets (201) with the shift synthesis gas (501, 523) Having at least two of the plant.

Images