Method, device and use for removing impurities from gasification gases and

Abstract

The present invention relates to a method and apparatus for removing impurities from a gasification gas. A gasification gas (1) containing at least tar and / or undesired hydrocarbons is fed to a catalytic reformer (2) containing at least one catalyst bed, an oxygen-containing gas (4) is injected onto the surface of the catalyst bed, the gasification gas (1) is arranged to flow through the catalyst bed (3) and contact the oxygen-containing gas (4) in the catalyst bed, and a purified gas (5) is discharged from the catalytic reformer (2). The present invention also relates to the use of this method.

Description

[Technical Field]

[0001] The present application relates to a method according to claim 1 and an apparatus according to claim 9 for removing impurities from gasification gas. Furthermore, the application relates to the use of the method according to claim 15. [Background technology]

[0002] It is known from the prior art that different biomass and waste materials are gasified in a gasifier to produce gasification gas. Furthermore, it is known that gasification gas contains impurities such as tar, some hydrocarbons, and other compounds. Furthermore, gas cleaning methods different from the prior art are known. Gasification gas can be cleaned through a number of cleaning steps. However, light hydrocarbons cannot be separated by cleaning. Furthermore, it is known that gasification gas can be cleaned by a catalytic reformer, which can convert tar and hydrocarbons into products. However, the structure of the reformer is complicated, with several different components and process steps. Furthermore, polycyclic aromatic hydrocarbons (PAHs) and carbon black are formed during catalytic reforming. Summary of the Invention [Problem to be solved by the invention]

[0003] The object of the present invention is to solve the above problems. Another object of the present invention is to disclose a new type of method and apparatus for removing impurities such as tar from gasification gas and purifying the gas. Another object of the present invention is to disclose a new type of method and apparatus for treating gasification gas and decomposing impurities. Another object of the present invention is to improve the quality of gasification gas. [Means for solving the problem]

[0004] The methods, devices and uses are characterized by what is presented in the claims.

[0005] In this method and apparatus, a gasification gas containing at least tar and / or undesired hydrocarbons is treated in a catalytic reformer containing at least one catalyst bed.

[0006] The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illustrate several embodiments of the invention and, together with the description, serve to explain the principles of the invention. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a flowchart diagram of a process according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] In a method for removing conversion impurities from a gasification gas, a gasification gas (1) containing at least tar and / or undesired hydrocarbons is fed to a catalytic reformer (2) containing at least one catalyst bed, an oxygen-containing gas (4) is injected onto the surface of the catalyst bed, the gasification gas (1) is arranged to flow through the catalyst bed (3) and contact the oxygen-containing gas (4) in the catalyst bed, and a purified gas (5) is discharged from the catalytic reformer (2). The gasification gas is treated with the oxygen-containing gas by catalytic oxidation and reforming in the catalyst bed, and the impurities are converted to produce the purified gas (5).

[0009] The apparatus for removing impurities from a gasification gas includes at least one catalytic reformer (2) to which a gasification gas (1) containing at least tar and / or undesired hydrocarbons is supplied, the catalytic reformer (2) including at least one catalyst bed. The apparatus further includes at least one injection device for injecting an oxygen-containing gas (4) onto the surface of the catalyst bed. In the reformer (2), the gasification gas (1) is arranged to flow through the catalyst bed (3) and contact the oxygen-containing gas (4) in the catalyst bed to convert the impurities and form a purified gas.

[0010] One embodiment of this method and apparatus is shown in FIG.

[0011] In this context, gasification gas (1) refers to any gasification gas, such as gasification gas, synthesis gas, or other gasification gas, that contains at least tar and / or undesired hydrocarbons as impurities. The gasification gas is composed of one or more primary components. The gasification gas can be primarily composed of carbon dioxide, carbon monoxide, hydrogen, and / or methane. Additionally, the gasification gas can also contain other components, such as inerts, dust, particulate matter, and / or water. Additionally, the gasification gas may contain other impurities. In one embodiment, at least tar is decomposed by the method. In one embodiment, at least undesired hydrocarbons, such as benzene, are decomposed by the method. In one embodiment, the gasification gas is a stream from a gasifier. In one embodiment, the gasification gas has been filtered after the gasifier.

[0012] In this context, oxygen-containing gas (4) refers to any gas, such as a reaction gas, that contains at least oxygen. The oxygen-containing gas may be composed of one or more main components. In one embodiment, the oxygen-containing gas consists of air. In one embodiment, the oxygen-containing gas consists of oxygen. In one embodiment, the oxygen-containing gas contains at least oxygen and nitrogen. In one embodiment, the oxygen-containing gas contains at least oxygen and steam. In one embodiment, the oxygen-containing gas contains at least oxygen and carbon dioxide. In one embodiment, the oxygen-containing gas contains at least oxygen, and further contains nitrogen, steam, and / or carbon dioxide. In one embodiment, the oxygen-containing gas is used as a reactant in the catalytic reformer (2). The oxygen-containing gas may have different oxygen contents. In one embodiment, the oxygen content in the oxygen-containing gas is 10 to 100 vol.%, and in one embodiment, 20 to 50 vol.%.

[0013] In one embodiment, the catalytic reformer (2) comprises one catalyst bed (3). In one embodiment, the catalytic reformer comprises multiple catalyst beds (3). In one embodiment, the catalytic reformer comprises at least two catalyst beds (3). In one embodiment, the catalytic reformer comprises two catalyst beds (3).

[0014] In this context, catalyst bed refers to any catalyst bed or layer within a catalytic reformer. In one embodiment, the catalyst bed is formed from catalyst particles. In one embodiment, the catalyst bed is formed from catalyst elements, the elements being coated with one or more catalysts.

[0015] In one embodiment, the catalyst bed (3) comprises at least one catalyst. In one embodiment, the catalyst bed is formed from one catalyst. In one embodiment, the catalyst bed (3) comprises two or more catalysts. In one embodiment, the gasifier encounters oxygen at a surface portion, such as a surface zone, of the catalyst bed. In one embodiment, the catalyst bed is formed from a first catalyst and the surface of the catalyst bed is formed from a second catalyst. In one embodiment, the gasifier encounters oxygen in a zone of the second catalyst.

[0016] In one embodiment, the catalyst is selected from a metal or a noble metal or other suitable catalyst. In one embodiment, the catalyst bed is formed from a Ni catalyst. In one embodiment, the catalyst bed is formed from a noble metal catalyst. In one embodiment, the catalyst bed is formed from a Ni catalyst and a noble metal catalyst. In one embodiment, a second catalyst disposed on the surface of the catalyst bed is formed from a robust catalyst that can withstand high temperatures and consume oxygen through a combustion reaction. In one embodiment, the first catalyst of the catalyst bed is a metal and / or noble metal catalyst. In one embodiment, the second catalyst of the catalyst bed is a Ni catalyst, for example, having a lower Ni content than the first catalyst. In one embodiment, the second catalyst is formed from a heat shield material with a lower nickel or noble metal content. In one embodiment, the first catalyst is formed from nickel and / or a noble metal.

[0017] The gasification gas (1) reacts with the oxygen-containing gas (4) in the catalyst bed (3). In one embodiment, the gasification gas (1) reacts with the oxygen-containing gas (4) on the surface of the catalyst particles in the catalyst bed (3). In one embodiment, the gasification gas (1) reacts with the oxygen-containing gas (4) within the pores of the catalyst in the catalyst bed (3). In one embodiment, the gasification gas (1) reacts with the oxygen-containing gas (4) on the surface of the catalyst particles in the catalyst bed or within the pores of the catalyst particles. When the gas reacts with the oxygen-containing gas in the catalyst bed, PAH compounds and carbon black are not formed, and catalyst deactivation can be avoided.

[0018] In one embodiment, the catalyst bed (3) is placed in a desired portion of the catalytic reformer (2).

[0019] In this context, catalytic reformer (2) means any reformer containing at least one catalyst bed. The catalytic reformer (2) can be a separate device or part of a separate device, for example part of a gasifier.

[0020] In one embodiment, the oxygen-containing gas (4) is injected by direct injection onto the surface of the catalyst bed (3). In one embodiment, the injection device is configured to inject the oxygen-containing gas (4) by direct injection onto the surface of the catalyst bed. The injection device for injecting the oxygen-containing gas (4) into the catalytic reformer (2) can be any injection device, injector, or other suitable injection device.

[0021] In one embodiment, the apparatus comprises at least one oxygen-containing gas feed inlet for feeding oxygen-containing gas (4) to the surface of the catalyst bed (3). In one embodiment, the oxygen-containing gas is fed to the catalyst bed by at least two oxygen-containing gas feed inlets. Preferably, the oxygen-containing gas is always fed to the surface of the catalyst bed (3).

[0022] In one embodiment, the apparatus comprises at least one gasification gas feed inlet for feeding the gasification gas (1) to the catalytic reformer (2). The gasification gas (1) is fed to the catalytic reformer (2) and arranged to flow through a catalyst bed. In one embodiment, the gasification gas (1) is fed before the catalyst bed (3) or directly to the catalyst bed (3) of the catalytic reformer (2). In one embodiment, the gasification gas feed inlet is arranged relative to the catalyst bed (3) of the catalytic reformer (2). In one embodiment, the gasification gas feed inlet is arranged before the catalyst bed (3) of the catalytic reformer (2).

[0023] In one embodiment, the apparatus comprises at least one outlet for discharging the purified gas (5) from the catalytic reformer (2).

[0024] The oxygen-containing gas supply inlet and the gasification gas supply inlet may be any suitable inlet such as a pipe, port, etc. known per se. The outlet may be any suitable outlet such as a pipe, outlet port, etc. known per se.

[0025] In one embodiment, when the gasification gas is supplied to the catalytic reformer (2), the temperature of the gasification gas (1) is 300°C to 900°C, and in one embodiment, 500°C to 850°C. In one embodiment, when the purified gas is discharged from the catalytic reformer (2), the temperature of the purified gas (5) is 800°C to 960°C, and in one embodiment, 850°C to 950°C.

[0026] The supply velocity of the oxygen-containing gas to the catalyst bed of the catalytic reformer is 5 m / s to 100 m / s. In one embodiment, the supply velocity of the oxygen-containing gas to the catalyst bed of the catalytic reformer is 10 m / s to 95 m / s, in one embodiment, 20 m / s to 90 m / s, and in one embodiment, 30 m / s to 80 m / s. In one embodiment, the supply velocity of the gasification gas to the catalyst bed of the catalytic reformer is 0.1 m / s to 3 m / s, and in one embodiment, 0.3 m / s to 2 m / s. When the oxygen-containing gas and the gasification gas are supplied to the catalyst bed, it is preferable that there is a sufficient difference between the supply velocities of the oxygen-containing gas and the gasification gas.

[0027] The purified gas (5) is produced in a catalytic reformer. In one embodiment, the tar content of the gas can be reduced. In one embodiment, the undesirable hydrocarbon content of the gas can be reduced.

[0028] In one embodiment, the purified gas (5) can be treated, post-treated, or fed to a subsequent process or process step after the catalytic reformer. In one embodiment, the purified gas is filtered. In one embodiment, the purified gas can be fed to a desired treatment process, such as, for example, to form hydrocarbons.

[0029] In one embodiment, the apparatus comprises two or more catalytic reformers. In one embodiment, at least two or more catalytic reformers are arranged in parallel. In one embodiment, at least two or more catalytic reformers are arranged in series.

[0030] In one embodiment, the method is based on a continuous process. In one embodiment, the apparatus is a continuous apparatus. In one embodiment, the method can be based on a batch process when the apparatus includes at least two parallel catalytic reformers.

[0031] In one embodiment, the apparatus and method can be used and utilized in gasification gas purification, gasification gas production, hydrocarbon production, methanol production, hydrogen production, fuel production, or combinations thereof. In one embodiment, the apparatus and method can be used to purify hot gases, such as pressurized hot gases. In one embodiment, the apparatus and method can be used to purify gases from oxygen gasification or steam gasification.

[0032] The present invention allows for purification of gasification gas, cracking and converting tar and / or undesirable hydrocarbons easily and effectively. Furthermore, carbon black formation may be eliminated or significantly reduced. This prevents clogging and blockage of the catalyst bed and reduces the pressure difference within the catalyst bed. When an oxygen-containing gas is supplied to the surface of the catalyst bed and arranged to contact the gasification gas within the catalyst bed rather than before the catalyst bed, reactions before the catalyst bed and catalyst deactivation can be avoided in catalytic reforming. Furthermore, in catalytic reforming, a higher oxygen partial pressure and a higher gasification gas supply temperature can be used.

[0033] The method and apparatus provide the possibility of purifying gasification gas and forming a purified gas stream, and also provide a product with good properties in an easy, energy- and cost-effective manner. The present invention provides an industrially applicable, simple, and affordable method for treating gasification gas containing impurities. Furthermore, the structure of the catalytic reformer can be simplified. In connection with the manufacturing process, the method and apparatus can be easily and simply implemented.

[0034] example Example 1 FIG. 1 shows a method and apparatus for converting impurities such as tar and unwanted hydrocarbons from gasification gas. The apparatus includes a catalytic reformer (2) to which a gasification gas (1) containing tar and undesired hydrocarbons is supplied. The catalytic reformer (2) includes a catalyst bed (3) formed from a first catalyst and a catalyst surface formed from a second catalyst. Alternatively, the catalytic reformer can include two or more catalyst beds. The apparatus further includes at least one injection device for injecting an oxygen-containing gas (4) by direct injection onto the surface of the catalyst bed. The oxygen-containing gas is supplied to the catalyst bed from the surface of the catalyst bed. In the catalytic reformer (2), the gasification gas (1) flows into the catalyst bed (3), through the catalyst bed, and is arranged to contact the oxygen-containing gas (4) within the catalyst bed. The gasification gas then reacts with the oxygen in the catalyst bed, and the gasification gas is processed by catalytic oxidation and reforming in the catalyst bed. Impurities can be converted during the reaction. Simultaneously, a purified gas (5) is produced during the reaction. The purified gas is discharged from the catalytic reformer (2).

[0035] Example 2 In this example, gasification gas (1) obtained by atmospheric steam gasification was purified in another catalytic reformer (2) according to Example 1.

[0036] Wood was gasified in an atmospheric dual fluidized bed steam gasifier operating at 785°C. The feed gas, i.e., gasification gas, was filtered at 675°C and led to a reformer consisting of two consecutive beds arranged according to Example 1. Both reforming beds were filled with a nickel-based catalyst. The feed gas at the inlet of the reformer contained 10.1 g / m 3 n benzene is a component heavier than naphthalene 6.5g / m 3 Contains 14.6g / m 3 The reformer contained tar of n. The content of light hydrocarbon gas at the inlet of the reformer was 6.55% methane (CH4), 0.13% ethyne (CH2), 2.12% ethene (CH2), 0.45% ethane (CH2), and a total of 0.08% C3-C5 hydrocarbons. A mixture of oxygen and nitrogen was fed to the first catalyst bed at a velocity of 61 m / s and to the second bed at a velocity of 69 m / s. The gas velocity before the first catalyst bed was 0.32 m / s, and before the second bed was 0.5 m / s. The temperature of the purified gas after reforming was 906°C.

[0037] The purified gas leaving the reformer contains 82 mg / m 3 n benzene and 40 mg / m 3 The benzene and tars contained 1.3% methane and 0.1% total C2-C5 hydrocarbon gases, respectively. The calculated conversions of C2-C5 hydrocarbon gases and heavy tars were 100%, 70.3% methane, 98.8%, and 99.9%, respectively.

[0038] This example was one setpoint in an extensive test campaign totaling 366 hours of operation using a variety of biomass feedstocks, including clean wood, bark, forest residues, straw, and demolition wood. The reformer operated without any signs of soot generation or increased pressure drop, and conversion efficiency remained high throughout the test.

[0039] Example 3 In this example, the gasification gas obtained in a pressurized steam oxygen gasification (1) was purified in another catalytic reformer (2) according to Example 1.

[0040] Wood was gasified in a pressurized circulating fluidized-bed gasifier operating at 0.3 MPa pressure, 920°C bed temperature, and 878°C in the upper part of the gasifier. Steam and oxygen were used as the feed gas. The gasified gas was filtered at 664°C and sent to the reformer. The reformer consisted of two consecutive fixed beds, each using a nickel catalyst as the main catalyst and a robust heat shield material with a low nickel content as the first layer of catalyst where the gasified gas and oxygen gases meet. The inlet gas velocity before the first bed was 1.0 m / s, and the oxygen flow velocity was 56 m / s. In the second reforming bed, the gas velocity was 1.3 m / s, and the oxygen flow velocity was 90 m / s. The oxygen flow was a mixture of oxygen and steam.

[0041] The reformer was operated at a relatively low temperature so that the outlet temperature of the purified gas was 835°C. As the objective of this test was to produce synthetic natural gas, the aim was to convert all hydrocarbon gases except for tar and methane.

[0042] The inlet benzene content was 8.1 g / m 3 n, tar content is 2.3 g / m 3 The methane concentration was 5.9%, and the total amount of C2-hydrocarbon gases was 0.79%. The concentration of benzene measured in the refined gas after reforming was 686 mg / m 3 n and tar at 20 mg / m 3 The purified gas contained 3.4% methane and less than 0.1% of the total C2-hydrocarbon gases. The calculated conversion efficiencies were 29.8% methane, 90.0% benzene, 99.0% tar, and 100.0% C2-hydrocarbon gases.

[0043] Example 3 is one test from an extensive test program involving a total of 4000 hours of operation, in which various reformer designs were tested in conjunction with a pressurized fluidized bed gasifier. At the end of this test campaign, a reformer was constructed and operated according to Example 1 with no signs of soot formation, stable pressure drop, and constant conversion efficiency.

[0044] The gasifier, catalytic reformer, feed and outlet devices of the processes used in these examples are known per se in the art and therefore will not be described in further detail in this context.

[0045] The method and apparatus are suitable for different embodiments for converting impurities in a gasification gas, purifying the gasification gas, and forming a purified gas.

[0046] The invention is not limited solely to the examples described above, but instead many variations are possible within the scope of the inventive idea as defined by the claims. [Explanation of symbols]

[0047] 1 Gasification gas 2. Catalytic reformer 3 Catalyst bed 4. Oxygen-containing gases 5. Purified Gas

Claims

1. 1. A method for removing impurities from a gasification gas, comprising: The gasification gas (1) containing at least tar and / or undesired hydrocarbons is supplied to a catalytic reformer (2) having at least one catalyst bed, the catalyst bed being formed from catalyst particles, and the supply velocity of the gasification gas (1) to the catalyst bed of the catalytic reformer is 0.1 m / s to 3 m / s; An oxygen-containing gas (4) is injected directly onto the surface of the catalyst bed, and the supply velocity of the oxygen-containing gas to the catalyst bed of the catalytic reformer is 20 m / s to 90 m / s; The gasification gas (1) is arranged to flow through the catalyst bed (3) and to contact the oxygen-containing gas (4) in the catalyst bed, where the gasification gas (1) reacts with the oxygen-containing gas (4) on the surfaces of the catalyst particles of the catalyst bed (3) or within the pores of the catalyst particles of the catalyst bed (3); A purified gas (5) is discharged from the catalytic reformer (2). A method characterized by:

2. 2. The method according to claim 1, characterized in that the catalyst bed (3) is formed from a first catalyst, the surface of the catalyst bed is formed from a second catalyst, the second catalyst is on the surface of the catalyst bed, and the gasification gas reacts with the oxygen-containing gas in a zone of the second catalyst.

3. 3. The method according to claim 1 or 2, characterized in that the gasification gas (1) is fed before the catalyst bed (3) of the catalytic reformer (2) or directly to the catalyst bed (3).

4. A method according to any one of claims 1 to 3, characterized in that the oxygen-containing gas (4) is injected by direct injection onto the surface of the catalyst bed.

5. The method according to any one of claims 1 to 4, characterized in that the oxygen content in the oxygen-containing gas is 10 to 100 vol %.

6. The method according to any one of claims 1 to 5, characterized in that the feed velocity of the oxygen-containing gas to the catalyst bed of the catalytic reformer is between 30m / s and 80m / s.

7. The method according to any one of claims 1 to 6, characterized in that the feed velocity of the gasification gas to the catalyst bed of the catalytic reformer is 0.3 m / s to 2 m / s.

8. An apparatus for removing impurities from gasification gas, comprising: at least one catalytic reformer (2) to which the gasification gas (1) containing at least tar and / or undesired hydrocarbons is supplied, the at least one catalytic reformer (2) comprising at least one catalyst bed, the catalyst bed being formed from catalyst particles and arranged so that the gasification gas flows through the catalyst bed of the catalytic reformer at a feed velocity of 0.1 m / s to 3 m / s; at least one injection device for injecting an oxygen-containing gas (4) directly onto the surface of the catalyst bed, the at least one injection device being arranged so that the oxygen-containing gas flows through the catalyst bed of the catalytic reformer at a feed velocity of 20 m / s to 90 m / s; Equipped with In the catalytic reformer (2), the gasification gas (1) is arranged to flow through the catalyst bed (3) and to contact the oxygen-containing gas (4) in the catalyst bed, and the gasification gas (1) reacts with the oxygen-containing gas (4) in the catalyst bed (3) on the surface of the catalyst particles of the catalyst bed (3) or in the pores of the catalyst particles of the catalyst bed (3). An apparatus characterized in that

9. 9. Apparatus according to claim 8, characterized in that the injection device is adapted to inject the oxygen-containing gas (4) by direct injection onto the surface of the catalyst bed.

10. 10. Apparatus according to claim 8 or 9, characterized in that the apparatus comprises at least one gasification gas feed inlet for feeding the gasification gas (1) to the catalytic reformer (2).

11. The apparatus according to any one of claims 8 to 10, characterized in that the apparatus comprises at least one gasification gas supply inlet for supplying the gasification gas (1) to the catalytic reformer (2), the gasification gas supply inlet being arranged before the catalyst bed (3) of the catalytic reformer (2).

12. 12. The apparatus according to claim 8, wherein the catalyst bed (3) is formed from a first catalyst, the surface of the catalyst bed is formed from a second catalyst, the second catalyst is on the surface of the catalyst bed, and the gasification gas reacts with the oxygen-containing gas in a zone of the second catalyst.

13. Device according to any one of claims 8 to 12, characterized in that the catalytic reformer comprises two catalyst beds (3).

14. 8. Use of the method according to any one of claims 1 to 7, characterized in that the method is used in the purification of the gasification gas, the production of the gasification gas, the production of hydrocarbons, the production of methanol, the production of hydrogen, the production of fuels, or a combination thereof.

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