Apparatus and method for removing carboxylic acid from a product gas containing carboxylic acid

Abstract

The present application relates to the field of gas purification, and particularly relates to a device for removing carboxylic acid from product gas containing carboxylic acid and a method thereof, the device comprising: a gas-solid separation zone for separating product gas containing carboxylic acid arranged in sequence from bottom to top in the height direction; the gas-solid separation zone comprising: a shell and a gas-solid separation unit provided in the shell and provided with an inlet for product gas containing carboxylic acid, an annular area formed by a gap between the outer wall of the gas-solid separation unit and the inner wall of the shell for receiving solid particles from the gas filtration zone, a solid particle collecting unit for receiving solid particles from the gas-solid separation unit, and a gas filtration zone and a hole plate arranged from top to bottom in the inner wall of the shell of the gas-solid separation zone, wherein the hole plate is provided with a gas material outlet of the gas separation unit communicating with the gas filtration zone. The device can reduce waste alkali discharge, improve the desolidification effect and the operation cycle of the device.

Description

Technical Field

[0001] This invention relates to the field of gas purification, and specifically to an apparatus and method for removing carboxylic acid from product gas containing carboxylic acid. Background Technology

[0002] Currently, carboxylation reactions have received widespread attention in decarboxylation reactions, particularly in the processing and upgrading of bio-oils. Loading single or multiple active components onto mesoporous supports can effectively improve the dispersibility and reactivity of these components on the support, and can provide a suitable chemical pore microenvironment for the transformation of some functional compounds with large molecular dynamic diameters.

[0003] There is still no unified understanding of the reaction mechanism of carboxylic acid ketylation, the number and properties of active sites on the catalyst, etc. However, it is generally believed that the ketylation reaction occurs on the coordinating unsaturated cations or oxygen vacancies on the catalyst surface, the carboxylate is adsorbed to form a transition species, and then the C-C bond couples to grow to form a ketone.

[0004] Oxygen-to-olefins (OTO) processes utilize oxygenated compounds such as methanol, ethanol, dimethyl ether, methyl ethyl ether, and dimethyl carbonate. Numerous technologies exist for producing these compounds, using feedstocks including coal, natural gas, and biomass. For instance, methanol can be produced from coal or natural gas, a mature process capable of achieving production scales of millions of tons. Due to the wide availability of oxygenated compounds and the economic viability of converting them to low-carbon olefins, OTO processes, particularly methanol-to-olefins (MTO) processes, are receiving increasing attention.

[0005] However, methanol-to-olefins (MTO) processes use acidic molecular sieve catalysts, and methanol and other oxygen-containing compounds often produce small amounts of small-molecule organic acids (mainly acetic acid and propionic acid) as byproducts. The pH of the liquid-phase products is between 3 and 4, and their corrosive effect on equipment in subsequent heat recovery and product separation units cannot be ignored. The traditional approach is to neutralize the product by adding a certain concentration of NaOH solution to control the pH of the quench water system to be greater than 7. Furthermore, to avoid corrosion from organic acids at the dew point, the reaction gas in traditional MTO processes is sent to the quench tower for water washing and separation after reaching approximately 190-230°C, resulting in a reduced heat recovery rate.

[0006] To address the aforementioned issues, once a suitable deacidification catalyst is obtained, and the catalytic conversion efficiency of organic acids in methanol-to-hydrocarbon reaction products can be improved, it is hoped that the problem of organic acid corrosion in methanol-to-hydrocarbon reaction production can be fundamentally solved. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of excessive emissions of waste gas, wastewater, and high material requirements of existing alkaline washing and acid removal methods, and to provide a device and method for removing carboxylic acid from product gas containing carboxylic acid. This device has advantages such as being able to convert organic acids into ketones for recycling, reducing waste alkali emissions, and extending the operating cycle of the decarboxylation device.

[0008] To achieve the above objectives, a first aspect of the present invention provides an apparatus for removing carboxylic acid from a product gas containing carboxylic acid, the apparatus comprising:

[0009] The structure, arranged from bottom to top along the vertical direction, includes: a gas-solid separation zone for separating carboxylic acid-containing product gas; a reaction zone for reacting the gaseous material from the gas-solid separation zone to obtain the product stream; and a decarboxylation product stream outlet within the reaction zone.

[0010] The gas-solid separation zone includes: a shell and a gas-solid separation unit with a product gas inlet containing carboxylic acid disposed inside the shell; an annular region formed by a gap between the outer wall of the gas-solid separation unit and the inner wall of the shell for receiving solid particles from a gas filtration zone; a solid particle collection unit for receiving solid particles from the gas separation unit; and a gas filtration zone and a perforated plate disposed from top to bottom on the inner wall of the shell of the gas-solid separation zone. The gas filtration zone is used to filter the gaseous stream from the gas separation unit, and the perforated plate is used to transfer solid particles from the gas filtration zone to the zone. The perforated plate is provided with a gas material outlet of the gas separation unit that communicates with the gas filtration zone.

[0011] A second aspect of the present invention provides a method for removing carboxylic acid from a product gas containing carboxylic acid, the method being carried out in the aforementioned apparatus, the method comprising:

[0012] The product gas containing carboxylic acid enters the gas-solid separation zone for gas-solid separation to obtain a gas stream, which is then sent to the reaction zone for decarboxylation reaction.

[0013] Through the above technical solution, the present invention has the following advantages:

[0014] The apparatus and method of the present invention can convert carboxylic acids in product gas containing carboxylic acids into ketones for recycling, reduce waste alkali emissions, improve the efficiency of solid removal from product gas, and extend the operating cycle of the decarboxylation unit. Attached Figure Description

[0015] Figure 1 This is a diagram of an apparatus for removing carboxylic acid from a product gas containing carboxylic acid, according to a preferred embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures

[0017] The system includes: carboxylic acid product gas inlet 1, gas-solid separation unit 2, decarboxylation catalytic reaction unit 3, inert packing unit 4, solid particle collection unit 5, orifice plate 6, solid particle storage tank 7, decarboxylation product logistics outlet 8, valves 9, 10, and 11, zone 12, gas material outlet of the gas-solid separation unit 13, gas filtration zone 14, gas-solid separation zone 15, and reaction zone 16. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used to describe the relative positions of components in relation to the directions shown in the accompanying drawings or in relation to the vertical, perpendicular, or gravitational directions; "inner" and "outer" refer to the interior and exterior of the cavity relative to the chamber or the radial interior and exterior relative to the center of the circle.

[0020] like Figure 1 As shown, the first aspect of the present invention provides an apparatus for removing carboxylic acid from a product gas containing carboxylic acid, the apparatus comprising:

[0021] A gas-solid separation zone 15 for separating carboxylic acid-containing product gas is arranged sequentially from bottom to top along the height direction; a reaction zone 16 for reacting the gaseous material from the gas-solid separation zone 15 to obtain a product stream; and a decarboxylation product stream outlet 8 is provided in the reaction zone 16.

[0022] The gas-solid separation zone 15 includes: a shell and a gas-solid separation unit 2 disposed inside the shell, which has a product gas inlet 1 containing carboxylic acid; an annular region 12 formed by a gap between the outer wall of the gas-solid separation unit 2 and the inner wall of the shell for receiving solid particles from the gas filtration zone 14; a solid particle collection unit 5 for receiving solid particles from the gas separation unit 2; and a gas filtration zone 14 and a perforated plate 6 disposed from top to bottom on the inner wall of the shell of the gas-solid separation zone 15. The gas filtration zone 14 is used to filter the gas phase stream from the gas separation unit, and the perforated plate 6 is used to transfer solid particles from the gas filtration zone 14 to the region 12. The perforated plate 6 is provided with a gas material outlet 13 of the gas separation unit that communicates with the gas filtration zone 14.

[0023] The device of this invention can convert carboxylic acids in product gas containing carboxylic acids into ketones for recycling, reduce waste alkali emissions, improve the efficiency of solid removal from product gas, and extend the operating cycle of the decarboxylation device.

[0024] In this invention, the edges of the gas filtration zone 14 and the perforated plate 6 are sealed on the inner wall of the housing of the gas-solid separation zone 15.

[0025] In this invention, the structure of the perforated plate 6 can be a conventional choice in the art. According to a preferred embodiment of this invention, the perforated plate 6 is at least one of a concave arc-shaped structure, an inverted conical structure, and a flat plate structure.

[0026] According to a preferred embodiment of the present invention, the gas-solid separation unit 2 includes at least one cyclone separator, preferably 12-20 cyclone separators.

[0027] In this invention, the cyclone separator can be a conventional choice in the art. According to a preferred embodiment of the invention, the ratio of the diameter of the cyclone separator cylinder to the height of the cyclone separator is 0.1-0.5; preferably 0.2-0.3. By adopting the aforementioned preferred solution, the efficiency of solid removal from the product gas can be further improved, and the operating cycle of the decarboxylation unit can be extended.

[0028] In this invention, the height of the cyclone separator = the height of the cylinder of the cyclone separator + the height of the cone of the cyclone separator.

[0029] In this invention, as long as the objective of the invention can be achieved, there is no particular limitation on the opening ratio of the orifice plate 6. According to a preferred embodiment of the invention, the opening ratio of the orifice plate 6 is not less than 50%, and preferably not less than 70%. By adopting the aforementioned preferred solution, the efficiency of solid removal from product gas can be further improved, and the operating cycle of the decarboxylation device can be extended.

[0030] According to a preferred embodiment of the present invention, the device further includes: a solid particle storage unit 7 for storing solid particles from the gas-solid separation unit 2; preferably, the solid particle storage unit 7 is connected to the region 12 and the solid particle collection unit 5 via a pipeline equipped with valves.

[0031] like Figure 1 The solid particle storage unit 7 is connected to the region 12 via a pipeline equipped with valve 10, and the solid particle storage unit 7 is connected to the solid particle collection unit 5 via a pipeline equipped with valve 9. Preferably, the solid particle storage unit 7 is provided with a solid particle outlet, and the discharge is controlled by valve 11.

[0032] According to a preferred embodiment of the present invention, the reaction zone (16) includes a decarboxylation catalytic reaction unit (3) and inert packing units (4) located at the upper and lower ends of the decarboxylation catalytic reaction unit (3), wherein the lower inert packing unit (4) is connected to the gas filtration zone (14).

[0033] A second aspect of the present invention provides a method for removing carboxylic acid from a product gas containing carboxylic acid, the method being carried out in the aforementioned apparatus, the method comprising:

[0034] The product gas containing carboxylic acid enters the gas-solid separation zone 15 for gas-solid separation to obtain a gas stream, which is then sent to the reaction zone 16 for decarboxylation reaction.

[0035] The method includes:

[0036] a. The product gas containing carboxylic acid enters the gas-solid separation unit 2 in the gas-solid separation zone 15 from the product gas inlet 1 containing carboxylic acid. The resulting gas material enters the gas filtration zone 14 from the gas material outlet 13 of the gas-solid separation unit 2 to further remove solid particles. Then, it passes through the reaction zone (16) for decarboxylation reaction. The decarboxylation product gas is sent to the next process from the decarboxylation product stream outlet (8). Preferably, it passes through the lower inert packing unit 4 of the reaction zone 16 and enters the decarboxylation catalytic reaction unit 3 for decarboxylation reaction. The decarboxylation product gas passes through the upper inert packing unit 4 and is sent to the next process from the decarboxylation product stream outlet 8.

[0037] b. The solid particles separated by the gas-solid separation unit 2 are sent from the solid particle outlet of the gas-solid separation unit 2 into the solid particle collection unit 5; the solid particles further separated by the gas filtration zone 14 enter the region 12 through the opening of the perforated plate 6, and the solid particles in the region 12 and the solid particles in the solid particle collection unit 5 are sent into the solid particle storage unit 7.

[0038] The method of this invention can convert carboxylic acids in product gas containing carboxylic acids into ketones for recycling, reduce waste alkali emissions, improve the efficiency of solid removal from product gas, and extend the operating cycle of the decarboxylation unit.

[0039] In this invention, the carboxylic acid in the product gas containing carboxylic acid can be a conventional choice in the art. According to a preferred embodiment of the invention, the carboxylic acid in the product gas contains straight-chain and / or branched carboxylic acids having 1-8 carbon atoms, preferably 1-4 carbon atoms. By adopting the aforementioned preferred scheme, waste alkali emissions can be further reduced, and the operating cycle of the decarboxylation unit can be extended.

[0040] According to a preferred embodiment of the present invention, the total content of carboxylic acid in the product gas containing carboxylic acid is not greater than 150 ppm, preferably 20-150 ppm.

[0041] According to a preferred embodiment of the present invention, the carboxylic acid-containing product gas is selected from the product gas prepared from oxygen-containing compounds for the production of low-carbon olefins.

[0042] In this invention, the conditions for the decarboxylation reaction can be conventional techniques in the art. According to a preferred embodiment of the invention, the conditions for the decarboxylation reaction include: a reaction temperature of 360-500℃, preferably 400-450℃; and / or a reaction pressure of 0.01-0.40 MPaG, preferably 0.1-0.2 MPaG; and / or a mass hourly space velocity (MSV) of the product gas containing carboxylic acid, calculated as carboxylic acid, of 0.1-20 h⁻¹. -1 Preferably 0.5-10h -1 By adopting the aforementioned preferred scheme, waste alkali emissions can be further reduced and the operating cycle of the decarboxylation unit can be extended.

[0043] In this invention, the catalyst for the decarboxylation reaction can be any conventionally chosen material in the art, as long as it achieves the objective of this invention. According to a preferred embodiment of this invention, the active component of the catalyst for the decarboxylation reaction includes Group IIA and Group IIIA metal oxides, and the density of the base centers of the catalyst is 0.5-2.5 μmol·m⁻¹. -2 Preferably, the base center density of the catalyst is 1.2-2.0 μmol·m⁻¹. -2 By adopting the aforementioned optimized methods, the removal rate of carboxylic acid can be significantly improved, waste alkali emissions can be reduced, and the operating cycle of the decarboxylation unit can be extended.

[0044] In this invention, as long as the objective of the invention can be achieved, the content of each component in the catalyst for the decarboxylation reaction is not particularly limited. According to a preferred embodiment of the invention, the catalyst for the decarboxylation reaction comprises 20-90 wt%, preferably 40-80 wt%, of Group IIA and Group IIIA metal oxides, and 10-80 wt%, preferably 20-60 wt%, of a third metal oxide active component. By adopting the aforementioned preferred embodiment, the removal rate of carboxylic acid can be further improved, the discharge of waste alkali can be reduced, and the operating cycle of the decarboxylation unit can be extended.

[0045] According to the present invention, the third metal oxide is a transition metal oxide, preferably at least one of Group IIB, Group IIIB, Group IVB, Group VIIB, and Group VIII metal oxides, and more preferably at least one of cerium oxide, iron oxide, titanium oxide, zinc oxide, manganese oxide, and cobalt oxide. By adopting the aforementioned preferred embodiment, the removal rate of carboxylic acid can be further improved, the discharge of waste alkali can be reduced, and the operating cycle of the decarboxylation unit can be extended.

[0046] In this invention, as long as the objective of the invention can be achieved, there is no particular limitation on the molar ratio of Group IIA metal elements to Group IIIA metal elements in the catalyst for the decarboxylation reaction. According to a preferred embodiment of the invention, the molar ratio of Group IIA metal elements to Group IIIA metal elements in the catalyst for the decarboxylation reaction is 1-10, preferably 2-6. By adopting the aforementioned preferred scheme, the removal rate of carboxylic acid can be further improved, the discharge of waste alkali can be reduced, and the operating cycle of the decarboxylation unit can be extended.

[0047] According to a preferred embodiment of the present invention, the Group IIA metal oxide in the catalyst for the decarboxylation reaction is selected from magnesium oxide and / or calcium oxide, preferably magnesium oxide and calcium oxide. By adopting the aforementioned preferred embodiment, the removal rate of carboxylic acid can be further improved, the discharge of waste alkali can be reduced, and the operating cycle of the decarboxylation unit can be extended.

[0048] According to a preferred embodiment of the present invention, the Group IIIA metal oxide in the catalyst for the decarboxylation reaction is selected from aluminum oxide. By adopting the aforementioned preferred embodiment, the removal rate of carboxylic acids can be further improved, waste alkali emissions can be reduced, and the operating cycle of the decarboxylation unit can be extended.

[0049] According to a preferred embodiment of the present invention, the catalyst for the decarboxylation reaction has a specific surface area of ​​50-300 m². 2 / g, preferably 150-250m 2 / g.

[0050] The present invention will be described in detail below through examples. In the following examples, the raw materials are all commercially available products.

[0051] Solid particle recovery rate = mass of solid particles discharged from solid particle storage tank 7 / total mass of solid particles entrained in product gas over 100 hours;

[0052] The total mass of solid particles entrained in the product gas over 100 hours = product gas flow rate × solid particle content in the product gas × 100 hours.

[0053] Example 1

[0054] Example 1 presents an apparatus and method for removing carboxylic acids, the apparatus being as follows: Figure 1 As shown, it includes the following steps:

[0055] The product gas containing carboxylic acid enters the gas-solid separation unit 2 in the gas-solid separation zone 15 from the product gas inlet 1 containing carboxylic acid. The resulting gas material enters the gas filtration zone 14 from the gas material outlet 13 of the gas-solid separation unit 2 to further remove solid particles. It then passes through the lower inert packing unit 4 of the reaction zone 16 and enters the decarboxylation catalytic reaction unit 3 for decarboxylation reaction. The decarboxylation product gas passes through the upper inert packing unit 4 and is sent to the next stage from the decarboxylation product stream outlet 8.

[0056] The solid particles separated by the gas-solid separation unit 2 are sent from the solid particle outlet of the gas-solid separation unit 2 into the solid particle collection unit 5; the solid particles further separated by the gas filtration zone 14 enter the zone 12 through the opening of the perforated plate 6, and the solid particles in the zone 12 and the solid particles in the solid particle collection unit 5 are sent into the solid particle storage tank 7 and discharged from the valve 11.

[0057] The perforated plate 6 has a concave arc-shaped structure; the gas-solid separation unit 2 includes 12 cyclone separators; the ratio of the diameter of the cylinder of the cyclone separator to the height of the cyclone separator is 0.25; and the perforation rate of the perforated plate 6 is 80%.

[0058] The product gas containing carboxylic acid was selected from the product gas generated from methanol preparation of low-carbon olefins. The carboxylic acid in the product gas was acetic acid, with a total content of 150 ppm by mass. The solid particulate matter content in the product gas was 110 mg / Nm³. 3 .

[0059] The conditions for the decarboxylation reaction were: reaction temperature 440℃; reaction pressure 0.15 MPaG; and the mass hourly space velocity (MSV) of the acetic acid-containing product gas (based on acetic acid) 8 h⁻¹. -1 .

[0060] The catalyst for the decarboxylation reaction comprises, by mass, 60 wt% magnesium oxide, 15 wt% aluminum oxide, and 25 wt% titanium oxide, and has a base center density of 1.8 μmol·m⁻¹. -2 The catalyst has a specific surface area of ​​220 m². 2 / g.

[0061] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 1 was calculated to be 2 ppm, and the solid particle recovery rate of solid particle storage tank 7 was 98.4%.

[0062] Example 2

[0063] The difference between Example 2 and Example 1 is as follows:

[0064] The perforated plate 6 has an inverted conical structure; the gas-solid separation unit 2 includes 16 cyclone separators; the ratio of the diameter of the cylinder of the cyclone separator to the height of the cyclone separator is 0.2; the perforation rate of the perforated plate 6 is 70%.

[0065] The conditions for the decarboxylation reaction were: reaction temperature 400℃; reaction pressure 0.2 MPaG; and the mass hourly space velocity (MSV) of the acetic acid-containing product gas (based on acetic acid) 10 h⁻¹. -1 .

[0066] The catalyst for the decarboxylation reaction comprises, by mass, 40 wt% magnesium oxide, 40 wt% aluminum oxide, and 20 wt% titanium oxide, with a base center density of 1.2 μmol·m⁻¹. -2 The catalyst has a specific surface area of ​​150 m². 2 / g.

[0067] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 2 was calculated to be 4 ppm, and the solid particle recovery rate of the solid particle storage tank 7 was 98.2%.

[0068] Example 3

[0069] The difference between Example 3 and Example 1 is as follows:

[0070] The perforated plate 6 has an inverted conical structure; the gas-solid separation unit 2 includes 20 cyclone separators; the ratio of the diameter of the cylinder of the cyclone separator to the height of the cyclone separator is 0.3; the perforation rate of the perforated plate 6 is 90%.

[0071] The conditions for the decarboxylation reaction were: reaction temperature 450℃; reaction pressure 0.1 MPaG; and the mass hourly space velocity (WHSV) of the acetic acid-containing product gas (based on acetic acid) 0.5 h⁻¹. -1 .

[0072] Example 3: The catalyst for the decarboxylation reaction comprised 20 wt% magnesium oxide, 20 wt% aluminum oxide, and 60 wt% titanium oxide by mass, with a base center density of 2.0 μmol·m⁻¹. -2 The catalyst has a specific surface area of ​​250 m². 2 / g.

[0073] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 3 was calculated to be 5 ppm, and the solid particle recovery rate of the solid particle storage tank 7 was 98.1%.

[0074] Example 4

[0075] The difference between Example 4 and Example 1 is that the ratio of the diameter of the cyclone separator cylinder to the height of the cyclone separator is 0.5.

[0076] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 4 was calculated to be 5 ppm, and the solid particle recovery rate of the solid particle storage tank 7 was 90.3%.

[0077] Example 5

[0078] The difference between Example 5 and Example 1 is that the gas-solid separation unit in Example 5 includes 4 cyclone separators; the ratio of the diameter of the cylinder of the cyclone separator to the height of the cyclone separator is 0.1.

[0079] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 5 was calculated to be 4 ppm, and the solid particle recovery rate of the solid particle storage tank 7 was 91.2%.

[0080] Example 6

[0081] The difference between Example 6 and Example 1 is that the perforation rate of the perforated plate 6 is 50%.

[0082] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 6 was calculated to be 4 ppm, and the solid particle recovery rate of the solid particle storage tank 7 was 95.1%.

[0083] Example 7

[0084] The difference between Example 7 and Example 1 is that the base center density of the catalyst for the decarboxylation reaction in Example 7 is 0.5 μmol·m. -2 .

[0085] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 7 was calculated to be 10 ppm, and the solid particle recovery rate of solid particle storage tank 7 was 98.3%.

[0086] Example 8

[0087] The difference between Example 8 and Example 1 is that the catalyst for the decarboxylation reaction in Example 8 contains only magnesium oxide and titanium oxide.

[0088] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 8 was calculated to be 23 ppm, and the solid particle recovery rate of the solid particle storage tank 7 was 98.0%.

[0089] Example 9

[0090] The difference between Example 9 and Example 1 is that the catalyst for the decarboxylation reaction in Example 9 contains only aluminum oxide and titanium oxide.

[0091] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 9 was calculated to be 30 ppm, and the solid particle recovery rate of the solid particle storage tank 7 was 98.0%.

[0092] Example 10

[0093] The difference between Example 10 and Example 1 is that the catalyst for the decarboxylation reaction in Example 10 contains only magnesium oxide and aluminum oxide.

[0094] After operating under these conditions for 100 hours, the acetic acid content in the decarboxylation product stream of Example 10 was calculated to be 49 ppm, and the solid particle recovery rate of the solid particle storage tank 7 was 98.2%.

[0095] Comparative Example 1

[0096] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not use the gas-solid separation unit of the present invention, and the product gas directly enters the reaction zone.

[0097] After operating under these conditions for 31 hours, the reaction zone became clogged and could not function properly.

[0098] Comparative Example 2

[0099] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, the product gas containing carboxylic acid is passed into a cyclone separator to remove solid particles, and then the gas phase is passed into an alkaline solution. After the carboxylic acid is absorbed by the alkaline solution, the decarboxylated product stream is sent to the next stage from outlet 8.

[0100] After running for 100 hours under these conditions, the acetic acid content in the decarboxylation product stream of Comparative Example 2 was calculated to be 15 ppm, and the solid particle recovery rate of solid particle storage tank 7 was 80.5%.

[0101] Comparative Example 3

[0102] The difference between Comparative Example 3 and Example 1 is that the device does not have a gas filtration zone 14 and a perforated plate.

[0103] After running for 100 hours under these conditions, the acetic acid content in the decarboxylation product stream of Comparative Example 3 was calculated to be 8 ppm, and the solid particle recovery rate of solid particle storage tank 7 was 80%.

[0104] After long-term operation, it was found that the operating cycle of the devices in Examples 1-3 reached nearly 8000 hours, and the operating cycle of the devices in Examples 4-6 reached 5000 hours, with phenomena such as decreased decarboxylation effect and increased pressure difference in the reaction zone. The operating cycle of the device in Comparative Example 3 was only 160 hours, and severe blockage occurred in the reaction zone.

[0105] The results of the examples and comparative examples show that the examples using the technical solution of the present invention have significantly better carboxylic acid removal effect, desolidification effect and longer operating cycle.

[0106] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An apparatus for removing carboxylic acid from a product gas containing carboxylic acid, characterized in that, The device includes: A gas-solid separation zone (15) for separating carboxylic acid-containing product gas is arranged sequentially from bottom to top in the height direction; a reaction zone (16) for reacting the gaseous material from the gas-solid separation zone (15) to obtain product stream; and a decarboxylation product stream outlet (8) is provided in the reaction zone (16); wherein, The gas-solid separation zone (15) includes: a shell and a gas-solid separation unit (2) with a product gas inlet (1) containing carboxylic acid disposed inside the shell; an annular region (12) formed by a gap between the outer wall of the gas-solid separation unit (2) and the inner wall of the shell for receiving solid particles from the gas filtration zone (14); a solid particle collection unit (5) for receiving solid particles from the gas-solid separation unit (2); the inner wall of the shell of the gas-solid separation zone (15) is provided with a gas filtration zone (14) and a perforated plate (6) from top to bottom; the gas filtration zone (14) is used to filter the gas phase stream from the gas separation unit; the perforated plate (6) is used to transfer solid particles from the gas filtration zone (14) to the annular region (12); wherein the perforated plate (6) is provided with a gas material outlet (13) of the gas separation unit connected to the gas filtration zone (14).

2. The apparatus according to claim 1, wherein, The perforated plate (6) is at least one of the following: a concave arc structure, an inverted cone structure, and a flat plate structure.

3. The apparatus according to claim 1, wherein, The gas-solid separation unit (2) includes at least one cyclone separator.

4. The apparatus according to claim 3, wherein, The gas-solid separation unit (2) includes 12-20 cyclone separators.

5. The apparatus according to claim 3, wherein, The ratio of the diameter of the cyclone separator cylinder to the height of the cyclone separator is 0.1-0.

5.

6. The apparatus according to claim 5, wherein, The ratio of the diameter of the cyclone separator cylinder to the height of the cyclone separator is 0.2-0.

3.

7. The apparatus according to claim 1, wherein, The perforation ratio of the perforated plate (6) is not less than 50%.

8. The apparatus according to claim 7, wherein, The perforation rate of the perforated plate (6) is not less than 70%.

9. The apparatus according to any one of claims 1-8, wherein, The device further includes: a solid particle storage unit (7) for storing solid particles from the gas-solid separation unit (2); and / or The reaction zone (16) includes a decarboxylation catalytic reaction unit (3) and inert packing units (4) located at the upper and lower ends of the decarboxylation catalytic reaction unit (3). The lower inert packing unit (4) is connected to the gas filtration zone (14).

10. The apparatus according to claim 9, wherein, The device further includes: the solid particle storage unit (7) is connected to the annular region (12) and the solid particle collection unit (5) via pipelines equipped with valves.

11. A method for removing carboxylic acid from a product gas containing carboxylic acid, characterized in that, The method is performed in the apparatus according to any one of claims 1-10, and the method includes: The product gas containing carboxylic acid enters the gas-solid separation zone (15) for gas-solid separation to obtain a gas stream, which is then sent to the reaction zone (16) for decarboxylation reaction.

12. The method according to claim 11, wherein, The method includes: a. The product gas containing carboxylic acid enters the gas-solid separation unit (2) in the gas-solid separation zone (15) from the product gas inlet (1) containing carboxylic acid. The resulting gas material enters the gas filtration zone (14) from the gas material outlet (13) of the gas-solid separation unit (2) to further remove solid particles. After that, it passes through the reaction zone (16) for decarboxylation reaction. The decarboxylated product gas is sent to the next section from the decarboxylated product stream outlet (8). b. The solid particles separated by the gas-solid separation unit (2) are sent from the solid particle outlet of the gas-solid separation unit (2) to the solid particle collection unit (5); the solid particles further separated by the gas filtration zone (14) enter the annular region (12) through the opening of the perforated plate (6), and the solid particles in the annular region (12) and the solid particles in the solid particle collection unit (5) are sent to the solid particle storage unit (7).

13. The method according to claim 11 or 12, wherein, The carboxylic acid in the product gas includes straight-chain and / or branched carboxylic acids having 1-8 carbon atoms; and / or The total carboxylic acid content in the product gas containing carboxylic acid is not greater than 150 ppm, and / or The product gas containing carboxylic acid is selected from the product gas prepared from oxygen-containing compounds for the production of low-carbon olefins.

14. The method according to claim 13, wherein, The carboxylic acid in the product gas containing carboxylic acid includes straight-chain and / or branched carboxylic acids having 1-4 carbon atoms.

15. The method according to claim 11 or 12, wherein, The conditions for the decarboxylation reaction include: a reaction temperature of 360-500℃; and / or The reaction pressure is 0.01-0.40 MPaG; and / or The mass hourly space velocity (MSV) of the product gas containing carboxylic acid, calculated as carboxylic acid, is 0.1-20 h⁻¹. -1 .

16. The method according to claim 15, wherein, The conditions for the decarboxylation reaction include: a reaction temperature of 400-450℃; and / or The reaction pressure is 0.1-0.2 MPaG; and / or The mass hourly space velocity (MSV) of the product gas containing carboxylic acid, calculated as carboxylic acid, is 0.5-10 h⁻¹. -1 .

17. The method according to claim 11 or 12, wherein, The active components of the catalyst for the decarboxylation reaction include group IIA metal oxides and group IIIA metal oxides, and the density of the base centers in the catalyst is 0.5-2.5 μmol·m⁻¹. -2 .

18. The method according to claim 17, wherein, The base center density of the catalyst is 1.2-2.0 μmol·m⁻¹. -2 .

19. The method according to claim 17, wherein, The catalyst for the decarboxylation reaction comprises 20-90 wt% of Group IIA and Group IIIA metal oxides, and 10-80 wt% of a third metal oxide active component.

20. The method according to claim 19, wherein, The catalyst for the decarboxylation reaction comprises 40-80 wt% of Group IIA and Group IIIA metal oxides, and 20-60 wt% of a third metal oxide active component.

21. The method according to claim 20, wherein, The third metal oxide is a transition metal oxide.

22. The method according to claim 21, wherein, The third metal oxide is at least one of Group IIB, Group IIIB, Group IVB, Group VIIB, and Group VIII metal oxides.

23. The method according to claim 22, wherein, The third metal oxide is at least one of cerium oxide, iron oxide, titanium oxide, zinc oxide, manganese oxide, and cobalt oxide.

24. The method of claim 17, wherein, The mass ratio of Group IIA metal oxides to Group IIIA metal oxides in the catalyst for the decarboxylation reaction is 1-10.

25. The method according to claim 24, wherein, The mass ratio of Group IIA metal oxides to Group IIIA metal oxides in the catalyst for the decarboxylation reaction is 2-6.

26. The method according to claim 17, wherein, The group IIA metal oxide in the catalyst for the decarboxylation reaction is selected from magnesium oxide and / or calcium oxide; and / or The group IIIA metal oxide in the catalyst for the decarboxylation reaction is selected from aluminum oxide.

27. The method according to claim 26, wherein, The group IIA metal oxides in the catalyst for the decarboxylation reaction are magnesium oxide and calcium oxide.

28. The method according to claim 17, wherein, The catalyst for the decarboxylation reaction has a specific surface area of ​​50-300 m². 2 / g.

29. The method according to claim 28, wherein, The catalyst for the decarboxylation reaction has a specific surface area of ​​150-250 m². 2 / g.

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