Activated carbon catalyst for phosgene synthesis and method of use thereof

Abstract

The application relates to an activated carbon catalyst for phosgene synthesis and an application method thereof. By controlling the endurance index a, the endurance index d and the endurance index f of the activated carbon catalyst in phosgene synthesis, the endurance performance of the activated carbon catalyst in a phosgene synthesis system is effectively improved, and the operation cycle is prolonged. The activated carbon catalyst is suitable for high-temperature operation conditions, so that high-boiling-point substances can be selected as the cooling medium for phosgene synthesis without considering the endurance capacity of the activated carbon.

Description

Technical Field

[0001] This invention relates to the field of phosgene synthesis technology, and more specifically to an activated carbon catalyst for phosgene synthesis and its application method. Background Technology

[0002] Phosgene, also known as carbonyl chloride, has a smell reminiscent of rotten licorice and rotten apples. As an important organic synthesis intermediate, it is mainly used in pesticides, coatings, dyes, initiators, pharmaceuticals, fine chemicals, and isocyanates. Industrially, phosgene is primarily produced using CO and Cl2 as raw materials in a tubular reactor packed with a catalyst.

[0003] Phosgene synthesis is a strongly exothermic reaction, with a heat release of 116 kJ / mol per unit of chlorine gas. Therefore, the heat of reaction must be removed promptly. Currently, phosgene synthesis reactors are mainly vertical tubular fixed-bed reactors with activated carbon catalyst in the tube side and cooling medium in the shell side.

[0004] CN 109289714A discloses a method for loading a catalyst for phosgene synthesis. The phosgene synthesis reaction includes: chlorine and carbon monoxide are mixed in a mixer and then reacted in reactor C1 to generate phosgene; the resulting mixture is then fed into reactor C2 to ensure complete chlorine reaction. The catalyst loading method in reactor C1 is as follows: a support mesh is installed at the bottom of reactor C1, Ф10 ceramic balls are placed at the bottom of each tube, and a sieve is pressed onto the upper part of the tube sheet. The catalyst loading method in reactor C2 is as follows: a cylinder is placed around the inlet pipe, Ф10 ceramic balls are placed in the gap between the inlet pipe and the cylinder, activated carbon is then added, two layers of sieve are pressed on top after filling, and finally Ф20 ceramic balls are added. However, this traditional loading method cannot reduce the reaction rate and exothermic rate, or prevent runaway temperatures; the pulverization and erosion of the activated carbon remains severe.

[0005] CN 110449147A discloses a catalyst for phosgene synthesis, its preparation method, and its application. The active components of the catalyst include activated carbon and carbon nanotubes. The preparation method includes: treating the activated carbon and carbon nanotubes in a nitric acid solution containing nitric acid; removing, washing, and drying to obtain a mixed powder of activated carbon and carbon nanotubes; mixing the mixed powder with a hydrochloric acid solution of polyvinyl alcohol and glutaraldehyde, kneading it into a plastic preform, extruding it into strips, and then ripening, drying, and calcining to obtain the catalyst for phosgene synthesis. The catalyst exhibits high activity, high thermal conductivity, and high structural stability.

[0006] CN 115667141A discloses a method for producing phosgene. This method involves a gas-phase reaction of carbon monoxide and chlorine in a multi-tube reactor in the presence of a carbon catalyst. The carbon catalyst includes a certain amount of mesopores with pore sizes ranging from 2 to 50 nm. By controlling the pore size distribution, the formation of the byproduct CCl4 is reduced. However, a comprehensive evaluation of the overall tolerance of the activated carbon catalyst for phosgene synthesis under phosgene synthesis conditions is not provided.

[0007] There is a contradiction between current mature technologies and technologies with high energy utilization rates: using water as a cooling medium cannot generate high-grade steam, resulting in energy waste and corrosion risks; while using high-boiling-point oil as a cooling medium will cause the operating temperature of the reaction tube to rise, activated carbon has poor high-temperature resistance and oxidation resistance, activated carbon is prone to ablation and pulverization, the service life of the reactor is shortened, and the stability of the device operation is poor.

[0008] To improve the energy utilization rate of phosgene synthesis and produce high-grade steam, it is necessary to clarify and control the factors affecting the heat resistance of activated carbon. Current technologies commonly employ complex modifications to enhance the heat resistance of activated carbon, but this method is costly and unsuitable for large-scale production. Since activated carbon is relatively inexpensive and some types possess desirable properties, it is feasible to apply it to phosgene synthesis steam generation systems. Therefore, providing activated carbon suitable for phosgene synthesis steam generation systems as a catalyst can be considered. This would improve the tolerance of activated carbon in the phosgene synthesis process, thereby enhancing the overall catalyst lifespan and energy utilization rate of the phosgene synthesis system, while also saving modification costs. Summary of the Invention

[0009] The purpose of this invention is to provide an activated carbon catalyst for phosgene synthesis and its application method. Three characteristic tolerance indices are formulated for phosgene synthesis conditions to ensure the tolerance performance of activated carbon that meets the conditions under phosgene synthesis conditions, thereby making it suitable for phosgene synthesis steam generation systems. This improves both the safe and stable operation of the equipment and the energy utilization efficiency of phosgene synthesis.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides an activated carbon catalyst for phosgene synthesis, wherein the tolerance index α of the activated carbon catalyst in phosgene synthesis is in the range of 1.0 × 10⁻⁶. 5 ~4.5×10 7 The tolerance index d ranges from 8.5 × 10⁻⁶. 2 ~1.0×10 6 The tolerance index f ranges from 3.0 × 10⁻⁶. 2 ~3.0×10 5 ;

[0012] The tolerance index a, tolerance index d, and tolerance index f are calculated using the following formula:

[0013] a = 0.0253 × b 2 +0.00093×(b / c) 2 ;

[0014] d = 0.0032 × e 2 +0.00038×(e / c) 2 ;

[0015] f = 0.0012 × g 2 +0.00025×(g / c) 2 ;

[0016] Where b is the total metal element content in the activated carbon catalyst, ppm; c is the pore volume of the activated carbon catalyst, mL / g; e is the aluminum element content in the activated carbon catalyst, ppm; and g is the iron element content in the activated carbon catalyst, ppm.

[0017] The activated carbon catalyst for phosgene synthesis provided by this invention, through extensive experiments using total metal element content, aluminum element content, iron element content, and pore volume as specific parameters, determined the optimal metal element to pore volume ratio for the activated carbon's tolerance performance, obtaining tolerance indices a, d, and f. By controlling these ranges, the tolerance performance of the activated carbon catalyst in the phosgene synthesis system is effectively improved, extending its service life. Furthermore, the activated carbon catalyst is suitable for high-temperature operating conditions, allowing the cooling medium for phosgene synthesis to be a high-boiling-point substance without considering the activated carbon's tolerance.

[0018] The tolerance index α of the activated carbon catalyst in phosgene synthesis ranges from 1.0 × 10⁻⁶. 5 ~4.5×10 7 For example, it could be 1.0 × 10 5 4.63×10 5 4.78×10 5 4.87×10 5 5.0×10 5 1.06×10 6 1.28×10 6 1.5×10 6 4.0×10 6 4.12×10 6 Or 4.5×10 7 However, this is not limited to the listed values; other unlisted values ​​within the range are also applicable, with 5.0 × 10⁻⁶ being the preferred value. 5 ~4.0×10 6 .

[0019] The tolerance index d of the activated carbon catalyst in phosgene synthesis ranges from 8.5 × 10⁻⁶. 2 ~1.0×10 6 For example, it could be 8.5 × 10 2 1.49×10 3 2.5×10 3 5.18×10 3 8.99×10 3 1.07×10 4 2.5×10 4 2.87×10 4 3.05×10 4 Or 1.0×10 6 However, this is not limited to the listed values; other unlisted values ​​within the range are also applicable, with 2.5 × 10⁻⁶ being the preferred value. 3 ~2.5×10 4 .

[0020] The tolerance index f of the activated carbon catalyst in phosgene synthesis ranges from 3.0 × 10⁻⁶. 2 ~3.0×10 5 For example, it could be 3.0 × 10 2 1.17×10 3 1.3×10 3 1.5×10 3 2.33×10 3 5.62×10 3 6.31×10 3 1.2×10 4 1.26×10 4 1.29×10 4 or 3.0×10 5 However, this is not limited to the listed values; other unlisted values ​​within the range are also applicable, with 1.5 × 10⁻⁶ being the preferred value. 3 ~1.2×10 4 .

[0021] Preferably, the total metal element content b in the activated carbon catalyst is 1500 to 21000 ppm, for example, it can be 1500 ppm, 4252 ppm, 4315 ppm, 4356 ppm, 6356 ppm, 7012 ppm, 7461 ppm, 12415 ppm, 15000 ppm or 20000 ppm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0022] Preferably, the pore volume c of the activated carbon catalyst is 0.1 to 3.0 mL / g, for example, it can be 0.1 mL / g, 0.76 mL / g, 0.81 mL / g, 0.94 mL / g, 1.12 mL / g, 1.62 mL / g, 1.64 mL / g, 1.81 mL / g, 2.0 mL / g or 3.0 mL / g, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0023] Preferably, the total aluminum content e in the activated carbon catalyst is 500 to 6000 ppm, for example, it can be 500 ppm, 671 ppm, 1245 ppm, 1574 ppm, 1792 ppm, 2754 ppm, 2812 ppm, 2950 ppm, 4000 ppm or 6000 ppm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0024] Preferably, the total iron content in the activated carbon catalyst is 500 to 4000 ppm, for example, it can be 500 ppm, 959 ppm, 1000 ppm, 1343 ppm, 1946 ppm, 2124 ppm, 2781 ppm, 2851 ppm or 4000 ppm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0025] Secondly, the present invention provides a method for applying the activated carbon catalyst as described in the first aspect, the method comprising the following steps:

[0026] Chlorine gas is mixed with carbon monoxide and then passed into a phosgene synthesis reactor containing an activated carbon catalyst to synthesize phosgene.

[0027] The activated carbon catalyst provided by this invention is suitable for high-temperature operating conditions. When used in phosgene synthesis, it can leverage the tolerance of the activated carbon catalyst in the phosgene synthesis system, allowing the cooling medium for phosgene synthesis to be a high-boiling-point substance without considering the tolerance of the activated carbon catalyst.

[0028] Preferably, the molar ratio of chlorine to carbon monoxide is (0.8 to 1):1, for example, it can be 0.8:1, 0.85:1, 0.93:1, 0.95:1 or 1:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] Preferably, the mixing method includes any one or a combination of at least two of pipe mixing, nozzle mixing, stirring mixing, or static mixer mixing. Typical but non-limiting combinations include a combination of stirring mixing and static mixer mixing, a combination of pipe mixing, nozzle mixing, and stirring mixing, or a combination of pipe mixing, nozzle mixing, stirring mixing, and static mixer mixing. Preferably, it is a combination of stirring mixing and static mixer mixing, and more preferably, it is static mixer mixing.

[0030] Preferably, the phosgene synthesis reactor includes any one of a tubular reactor, a spiral reactor, a fixed-bed tubular reactor, or a double-tube sheet fixed-bed reactor, with a fixed-bed tubular reactor being the most preferred.

[0031] Preferably, the gauge pressure of the phosgene synthesis reaction apparatus is 0.1 to 0.5 MPa, for example, it can be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa or 0.5 MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0032] Preferably, the inlet temperature of the phosgene synthesis reaction device is 10 to 60°C, for example, it can be 10°C, 20°C, 30°C, 40°C or 60°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably 20 to 40°C.

[0033] Preferably, the outlet temperature of the phosgene synthesis reaction device is 40 to 350°C, for example, it can be 40°C, 50°C, 60°C, 250°C or 350°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably 50 to 250°C.

[0034] In this invention, the phosgene synthesis reaction apparatus is provided with a coolant flow space, in which coolant flows to absorb the reaction heat generated during phosgene synthesis; wherein, the coolant flow space is provided on the shell side of the phosgene synthesis reaction apparatus, specifically the space surrounding the tubes inside the phosgene synthesis reaction apparatus.

[0035] It should be noted that those skilled in the art can obtain activated carbon catalysts that meet the requirements of tolerance index a, tolerance index d, and tolerance index f by adjusting the type and amount of reagents, treatment temperature, and time for activated carbon treatment.

[0036] As a preferred embodiment of the application method described in this invention, the application method includes the following steps:

[0037] Chlorine gas and carbon monoxide are mixed in a molar ratio of (0.8–1.0):1, and then introduced into a phosgene synthesis reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reactor has a gauge pressure of 0.1–0.5 MPa, an inlet temperature of 10–60°C, and an outlet temperature of 40–350°C to synthesize phosgene.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The activated carbon catalyst for phosgene synthesis provided by this invention effectively improves the tolerance performance of the activated carbon catalyst in the phosgene synthesis system by controlling the range of tolerance index a, tolerance index d, and tolerance index f. The annual mass loss of the activated carbon catalyst is as low as 1.98%, and the operating cycle of the activated carbon catalyst is >3000 days. The activated carbon catalyst is suitable for high-temperature operating conditions, allowing the cooling medium for phosgene synthesis to be a high-boiling-point substance without considering the tolerance of the activated carbon. Detailed Implementation

[0040] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0041] Raw materials and sources:

[0042] Carbon monoxide (industrial product), produced by gasification equipment in Yantai Wanhua Industrial Park;

[0043] Chlorine (industrial product), produced in the chlorine and hydrogen workshop of Yantai Wanhua Chlor-Alkali Company.

[0044] Test method:

[0045] Metal content determination: The activated carbon catalyst was digested by microwave and then the metal content was determined by ICP.

[0046] Pore ​​volume determination: The pore volume of the activated carbon catalyst was determined by measuring the amount of nitrogen or carbon dioxide adsorbed on the activated carbon catalyst using a dual isotherm NLDFT advanced pore size distribution instrument.

[0047] Example 1

[0048] This embodiment provides an activated carbon catalyst for phosgene synthesis, wherein the activated carbon catalyst has a tolerance index α of 1.06 × 10⁻⁶ in phosgene synthesis. 6 The tolerance index d is 8.99×10. 3 The tolerance index f was 5.62 × 10⁻⁶. 3 ;

[0049] The tolerance index a, tolerance index d, and tolerance index f are calculated using the following formula:

[0050] a = 0.0253 × b 2 +0.00093×(b / c) 2 ;

[0051] d = 0.0032 × e 2 +0.00038×(e / c) 2 ;

[0052] f = 0.0012 × g 2 +0.00025×(g / c) 2 ;

[0053] Among them, the total metal element content b in the activated carbon catalyst is 6356 ppm; the pore volume c of the activated carbon catalyst is 0.94 mL / g; the aluminum element content e in the activated carbon catalyst is 1574 ppm; and the iron element content g in the activated carbon catalyst is 1946 ppm.

[0054] The method for applying the activated carbon catalyst for phosgene synthesis includes the following steps:

[0055] Chlorine and carbon monoxide at a molar ratio of 0.93:1 are mixed in a static mixer and then passed into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reactor has a gauge pressure of 0.4 MPa, an inlet temperature of 30°C, and an outlet temperature of 60°C to synthesize phosgene.

[0056] Example 2

[0057] This embodiment provides an activated carbon catalyst for phosgene synthesis, wherein the activated carbon catalyst has a tolerance index α of 4.87 × 10⁻⁶ in phosgene synthesis. 5 The tolerance index d was 5.18 × 10⁻⁶. 3 The tolerance index f was 2.33 × 10⁻⁶. 3 ;

[0058] The tolerance index a, tolerance index d, and tolerance index f are calculated using the following formula:

[0059] a = 0.0253 × b 2 +0.00093×(b / c) 2 ;

[0060] d = 0.0032 × e 2 +0.00038×(e / c) 2 ;

[0061] f = 0.0012 × g 2 +0.00025×(g / c) 2 ;

[0062] Among them, the total metal element content b in the activated carbon catalyst is 4356 ppm; the pore volume c of the activated carbon catalyst is 1.64 mL / g; the aluminum element content e in the activated carbon catalyst is 1245 ppm; and the iron element content g in the activated carbon catalyst is 1343 ppm.

[0063] The method for applying the activated carbon catalyst for phosgene synthesis includes the following steps:

[0064] Chlorine and carbon monoxide at a molar ratio of 0.85:1 are mixed in a static mixer and then passed into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reactor has a gauge pressure of 0.2 MPa, an inlet temperature of 20°C, and an outlet temperature of 50°C to synthesize phosgene.

[0065] Example 3

[0066] This embodiment provides an activated carbon catalyst for phosgene synthesis, wherein the tolerance index α of the activated carbon catalyst in phosgene synthesis is 1.28 × 10⁻⁶. 6 The tolerance index d is 3.05×10. 4 The tolerance index f was 6.31 × 10⁻⁶. 3 ;

[0067] The tolerance index a, tolerance index d, and tolerance index f are calculated using the following formula:

[0068] a = 0.0253 × b 2 +0.00093×(b / c) 2 ;

[0069] d = 0.0032 × e 2 +0.00038×(e / c) 2 ;

[0070] f = 0.0012 × g 2 +0.00025×(g / c) 2 ;

[0071] The total metal element content (b) in the activated carbon catalyst is 7012 ppm; the pore volume (c) of the activated carbon catalyst is 1.12 mL / g; the aluminum element content (e) of the activated carbon catalyst is 2950 ppm; and the iron element content (g) of the activated carbon catalyst is 2124 ppm.

[0072] The method for applying the activated carbon catalyst for phosgene synthesis includes the following steps:

[0073] Chlorine and carbon monoxide at a molar ratio of 0.95:1 are mixed in a static mixer and then passed into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reactor has a gauge pressure of 0.3 MPa, an inlet temperature of 40°C, and an outlet temperature of 250°C to synthesize phosgene.

[0074] Example 4

[0075] This embodiment provides an activated carbon catalyst for phosgene synthesis, wherein the activated carbon catalyst has a tolerance index α of 4.78 × 10⁻⁶ in phosgene synthesis. 5 The tolerance index d is 1.07 × 10⁻⁶. 4 The tolerance index f is 1.30 × 10⁻⁶. 3 ;

[0076] The tolerance index a, tolerance index d, and tolerance index f are calculated using the following formula:

[0077] a = 0.0253 × b 2 +0.00093×(b / c) 2 ;

[0078] d = 0.0032 × e 2 +0.00038×(e / c) 2 ;

[0079] f = 0.0012 × g 2 +0.00025×(g / c) 2 ;

[0080] Among them, the total metal element content b in the activated carbon catalyst is 4315 ppm; the pore volume c of the activated carbon catalyst is 1.62 mL / g; the aluminum element content e in the activated carbon catalyst is 1792 ppm; and the iron element content g in the activated carbon catalyst is 1000 ppm.

[0081] The method for applying the activated carbon catalyst for phosgene synthesis includes the following steps:

[0082] Chlorine and carbon monoxide in a molar ratio of 0.8:1 are stirred and mixed in a static mixer, and then passed into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reactor has a gauge pressure of 0.1 MPa, an inlet temperature of 10°C, and an outlet temperature of 40°C to synthesize phosgene.

[0083] Example 5

[0084] This embodiment provides an activated carbon catalyst for phosgene synthesis, wherein the tolerance index α of the activated carbon catalyst in phosgene synthesis is 1.50 × 10⁻⁶. 6 The tolerance index d is 3.05×10.4 The tolerance index f was 1.26 × 10⁻⁶. 4 ;

[0085] The tolerance index a, tolerance index d, and tolerance index f are calculated using the following formula:

[0086] a = 0.0253 × b 2 +0.00093×(b / c) 2 ;

[0087] d = 0.0032 × e 2 +0.00038×(e / c) 2 ;

[0088] f = 0.0012 × g 2 +0.00025×(g / c) 2 ;

[0089] Among them, the total metal element content b in the activated carbon catalyst is 7461 ppm; the pore volume c of the activated carbon catalyst is 0.76 mL / g; the aluminum element content e in the activated carbon catalyst is 2812 ppm; and the iron element content g in the activated carbon catalyst is 2781 ppm.

[0090] The method for applying the activated carbon catalyst for phosgene synthesis includes the following steps:

[0091] Chlorine and carbon monoxide in a 1:1 molar ratio are stirred and mixed in a static mixer, and then introduced into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reactor has a gauge pressure of 0.5 MPa, an inlet temperature of 60°C, and an outlet temperature of 350°C to synthesize phosgene.

[0092] Example 6

[0093] This embodiment provides an activated carbon catalyst for phosgene synthesis, wherein the tolerance index α of the activated carbon catalyst in phosgene synthesis is 4.12 × 10⁻⁶. 6 The tolerance index d is 2.87 × 10⁻⁶. 4 The tolerance index f was 1.29 × 10⁻⁶. 4 ;

[0094] The tolerance index a, tolerance index d, and tolerance index f are calculated using the following formula:

[0095] a = 0.0253 × b 2 +0.00093×(b / c) 2 ;

[0096] d = 0.0032 × e 2 +0.00038×(e / c)2 ;

[0097] f = 0.0012 × g 2 +0.00025×(g / c) 2 ;

[0098] Among them, the total metal element content b in the activated carbon catalyst is 12415 ppm; the pore volume c of the activated carbon catalyst is 0.81 mL / g; the aluminum element content e in the activated carbon catalyst is 2754 ppm; and the iron element content g in the activated carbon catalyst is 2851 ppm.

[0099] The method for applying the activated carbon catalyst for phosgene synthesis includes the following steps:

[0100] Chlorine and carbon monoxide at a molar ratio of 0.93:1 are mixed in a static mixer and then passed into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reactor has a gauge pressure of 0.4 MPa, an inlet temperature of 30°C, and an outlet temperature of 60°C to synthesize phosgene.

[0101] Example 7

[0102] This embodiment provides an activated carbon catalyst for phosgene synthesis, wherein the activated carbon catalyst has a tolerance index α of 4.63 × 10⁻⁶ in phosgene synthesis. 5 The tolerance index d was 1.49 × 10⁻⁶. 3 The tolerance index f was 1.17 × 10⁻⁶. 3 ;

[0103] The tolerance index a, tolerance index d, and tolerance index f are calculated using the following formula:

[0104] a = 0.0253 × b 2 +0.00093×(b / c) 2 ;

[0105] d = 0.0032 × e 2 +0.00038×(e / c) 2 ;

[0106] f = 0.0012 × g 2 +0.00025×(g / c) 2 ;

[0107] Among them, the total metal element content b in the activated carbon catalyst is 4252 ppm; the pore volume c of the activated carbon catalyst is 1.81 mL / g; the aluminum element content e in the activated carbon catalyst is 671 ppm; and the iron element content g in the activated carbon catalyst is 959 ppm.

[0108] The method for applying the activated carbon catalyst for phosgene synthesis includes the following steps:

[0109] Chlorine and carbon monoxide at a molar ratio of 0.93:1 are mixed in a static mixer and then passed into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reactor has a gauge pressure of 0.4 MPa, an inlet temperature of 30°C, and an outlet temperature of 60°C to synthesize phosgene.

[0110] Comparative Example 1

[0111] This comparative example provides an activated carbon catalyst for phosgene synthesis. The difference from Example 1 is that the total metal element content (b), pore volume (c), aluminum content (e), and iron content (g) in the activated carbon catalyst are adjusted, resulting in an adaptability tolerance index (a) of 9.14 × 10⁻⁶. 4 The tolerance index d is 1.86×10. 2 The tolerance index f was 2.78 × 10⁻⁶. 2 Everything else is the same as in Example 1.

[0112] Comparative Example 2

[0113] This comparative example provides an activated carbon catalyst for phosgene synthesis. The difference from Example 1 is that the total metal element content (b), pore volume (c), aluminum content (e), and iron content (g) in the activated carbon catalyst are adjusted, resulting in an adaptability tolerance index (a) of 6.82 × 10⁻⁶. 7 The tolerance index d is 3.23 × 10⁻⁶. 6 The tolerance index f was 7.17 × 10⁻⁶. 5 Everything else is the same as in Example 1.

[0114] Comparative Example 3

[0115] This comparative example provides an activated carbon catalyst for phosgene synthesis. The difference from Example 1 is that the total metal element content (b), pore volume (c), aluminum content (e), and iron content (g) in the activated carbon catalyst are adjusted, resulting in an adaptability tolerance index (a) of 9.14 × 10⁻⁶. 4 The tolerance index d is 2.23 × 10⁻⁶. 2 The tolerance index f was 3.58 × 10⁻⁶. 3 Everything else is the same as in Example 1.

[0116] Comparative Example 4

[0117] This comparative example provides an activated carbon catalyst for phosgene synthesis. The difference from Example 1 is that the total metal element content (b), pore volume (c), aluminum content (e), and iron content (g) in the activated carbon catalyst are adjusted, resulting in an adaptability tolerance index (a) of 1.24 × 10⁻⁶. 8The tolerance index d is 1.76 × 10⁻⁶. 4 The tolerance index f was 7.74 × 10⁻⁶. 4 Everything else is the same as in Example 1.

[0118] Phosgene was synthesized using the activated carbon catalysts provided in Examples 1-7 and Comparative Examples 1-4. The annual mass loss of the activated carbon catalysts was calculated, and the operating cycle of the activated carbon catalysts was recorded. The results are shown in Table 1.

[0119] Table 1

[0120] Annual mass loss (%) Operating cycle (d) Example 1 1.98 ＞3000 Example 2 4.65 >1400 Example 3 4.52 >1400 Example 4 7.79 ＜850 Example 5 8.03 ＜820 Example 6 10.05 ＜620 Example 7 11.10 ＜600 Comparative Example 1 19.78 ＜300 Comparative Example 2 18.82 ＜300 Comparative Example 3 20.70 ＜300 Comparative Example 4 21.05 ＜300

[0121] As can be seen from Table 1, by precisely controlling the three characteristic tolerance indices, the activated carbon catalyst provided by this invention can effectively improve the tolerance performance of the activated carbon catalyst under phosgene synthesis conditions and extend the operating cycle when synthesizing phosgene.

[0122] As can be seen from the comparison between Example 1 and Comparative Examples 1-4, if the tolerance index a, tolerance index d and tolerance index f all exceed the limit range, the tolerance performance of the activated carbon catalyst will be significantly reduced, thereby increasing the annual mass loss and shortening the operating cycle; if only one or two tolerance indices exceed the limit range, the tolerance performance of the activated carbon catalyst will also be reduced, and the operating cycle will be shortened.

[0123] In summary, the activated carbon catalyst for phosgene synthesis provided by this invention effectively improves the tolerance performance of the activated carbon catalyst in the phosgene synthesis system by controlling the range of tolerance indices a, d, and f. The annual mass loss of the activated carbon catalyst is as low as 1.98%, and the operating cycle of the activated carbon catalyst is >3000 days. The activated carbon catalyst is suitable for high-temperature operating conditions, allowing the cooling medium for phosgene synthesis to be a high-boiling-point substance without considering the tolerance of the activated carbon.

[0124] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An activated carbon catalyst for the synthesis of phosgene, characterized in that, The active carbon catalysts have a resistance index a in the range from 1.0 x 10 5 -4.5 x 10 7 -8.5 x 10 2 -1.0 x 10 6 -3.0 x 10 2 -3.0 x 10 5 ; The tolerance index a, the tolerance index d and the tolerance index f are calculated by the following formula: a = 0.0253 x b 2 + 0.00093 x (b / c) 2 ; d = 0.0032 x e 2 + 0.00038 x (e / c) 2 ; f = 0.0012 x g 2 + 0.00025 x (g / c) 2 ; Wherein, b is the total content of metal elements in the activated carbon catalyst, ppm; c is the pore volume of the activated carbon catalyst, mL / g; e is the content of aluminum elements in the activated carbon catalyst, ppm; g is the content of iron elements in the activated carbon catalyst, ppm; The total content of metal elements b in the activated carbon catalyst is 1500-21000 ppm; the pore volume c of the activated carbon catalyst is 0.1-3.0 mL / g; the total content of aluminum elements e in the activated carbon catalyst is 500-6000 ppm; and the total content of iron elements g in the activated carbon catalyst is 500-4000 ppm.

2. The activated carbon catalyst according to claim 1, characterized by The resistance index a of the activated carbon catalyst in the synthesis of phosgene ranges from 5.0 x 10 5 4.0 x 10 6 .

3. The activated carbon catalyst according to claim 1 or 2, characterized in that, The resistance index d of the activated carbon catalyst in the synthesis of phosgene ranges from 2.5 x 10 3 2.5 x 10 4 .

4. The activated carbon catalyst according to claim 1, characterized by The resistance index f of the activated carbon catalyst in the synthesis of phosgene ranges from 1.5 x 10 3 -1.2 x 10 4 .

5. A method for using the activated carbon catalyst according to any one of claims 1 to 4, characterized by, The application method comprises the following steps: The chlorine and the carbon monoxide are mixed, and then introduced into a phosgene synthesis reaction device containing the activated carbon catalyst to react to synthesize phosgene.

6. The use according to claim 5, characterized in that, The molar ratio of the chlorine to the carbon monoxide is (0.8-1):

1.

7. The use according to claim 5, characterized in that, The mixing mode comprises any one or a combination of at least two of pipe mixing, nozzle mixing, stirring mixing or static mixer mixing.

8. The use according to claim 5, characterized in that, The phosgene synthesis reaction device comprises any one of a tube-type reaction tube, a spiral tube-type reactor, a fixed bed tube-type reactor or a double-tube plate fixed bed reactor.

9. The method of claim 8, wherein, The phosgene synthesis reaction device is a fixed bed tube-type reactor.

10. The use according to claim 5, characterized in that, The phosgene synthesis reaction device has a gauge pressure of 0.1-0.5 MPa.

11. The use according to claim 5, characterized in that, The phosgene synthesis reaction device has an inlet temperature of 10-60℃.

12. The method of claim 11, wherein, The phosgene synthesis reaction device has an inlet temperature of 20-40℃.

13. The method for use according to claim 5, characterized in that, The phosgene synthesis reaction device has an outlet temperature of 40-350℃.

14. The method of claim 13, wherein, The phosgene synthesis reaction device has an outlet temperature of 50-250℃.

15. The method of claim 5, wherein the compound is administered in an amount of about 0.1 to 10 mg / kg. The application method comprises the following steps: The chlorine and the carbon monoxide are mixed, and then introduced into a phosgene synthesis reaction device containing the activated carbon catalyst to react to synthesize phosgene. The molar ratio of the chlorine to the carbon monoxide is (0.8-1):

1. The phosgene synthesis reaction device has a gauge pressure of 0.1-0.5 MPa, an inlet temperature of 10-60℃ and an outlet temperature of 40-350℃.