Activated carbon catalyst for phosgene synthesis and method using same

Abstract

Provided are an activated carbon catalyst for phosgene synthesis and a method using same. By controlling a tolerance index a, a tolerance index d, and a tolerance index f of the activated carbon catalyst in phosgene synthesis, the tolerance performance of the activated carbon catalyst in a phosgene synthesis system is effectively improved, leading to an extended operation period. The activated carbon catalyst is suitable for high-temperature operation conditions, enabling the selection of a high-boiling-point substance as a cooling medium for the phosgene synthesis without needing to consider the tolerance of the activated carbon.

Description

Activated carbon catalyst for phosgene synthesis and application method thereof Technical Field

[0001] The present application relates to the technical field of phosgene synthesis, and in particular to an activated carbon catalyst for phosgene synthesis and an application method thereof. Background Art

[0002] Phosgene, also known as carbonyl chloride, has an odor reminiscent of rotten licorice and apple. As an important organic synthesis intermediate, it is primarily used in pesticides, coatings, dyes, initiators, pharmaceuticals, fine chemicals, and isocyanates. Industrial production of phosgene primarily uses CO and Cl2 as raw materials in a shell-and-tube reactor loaded with a catalyst.

[0003] Phosgene synthesis is a highly exothermic reaction, releasing 116 kJ / mol of heat per unit of chlorine. Therefore, the reaction heat must be removed promptly. Currently, phosgene synthesis reactors are primarily 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 a phosgene synthesis reaction. The phosgene synthesis reaction includes: chlorine and carbon monoxide are mixed in a mixer and then introduced into a C1 reactor to react and generate phosgene; the reacted mixture is then fed into a C2 reactor to ensure complete chlorine reaction. The catalyst loading method in the C1 reactor includes: installing a support mesh at the bottom of the C1 reactor, loading Ø10 porcelain balls into the bottom of each tube, and then pressing a screen onto the upper portion of the tube plate; the catalyst loading method in the C2 reactor includes: placing a cylinder around the inlet tube, loading Ø10 porcelain balls into the gap between the inlet tube and the cylinder, then loading activated carbon, pressing two layers of screen onto the gap, and finally loading Ø20 porcelain balls. However, this traditional loading method fails to reduce the reaction rate and heat release rate, prevent heat runaway, and still results in severe activated carbon pulverization and ablation.

[0005] CN 110449147A discloses a catalyst for phosgene synthesis, its preparation method, and application. The catalyst's active components include activated carbon and carbon nanotubes. The preparation method comprises: treating the activated carbon and carbon nanotubes in a nitric acid solution containing tris(III) nitric acid, washing, and drying to obtain a mixed powder of the activated carbon and carbon nanotubes; uniformly mixing the mixed powder with a hydrochloric acid solution of polyvinyl alcohol and glutaraldehyde, kneading the mixed powder into a plastic body, extruding the mixed powder into strips, and then aging, drying, and calcining the mixed powder 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 a pore size range of 2-50 nm. By controlling the pore size distribution, the formation of the byproduct CCl4 is reduced. However, no comprehensive evaluation of the overall tolerance of the activated carbon catalyst under phosgene synthesis conditions was conducted.

[0007] There is a contradiction between the current mature technology and the technology with higher energy utilization rate: using water as the cooling medium cannot produce high-grade steam, resulting in energy waste and corrosion risk; using high-boiling point oil as the cooling medium will cause the operating temperature of the reaction tube to rise, the activated carbon has poor high temperature resistance and antioxidant properties, the activated carbon is easily ablated and pulverized, the reactor service life is shortened, and the device operation stability is poor.

[0008] In order 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. The commonly used method in the existing technology is to perform complex modifications on activated carbon to enhance its heat resistance, but this method is expensive and not suitable for large-scale production. Since the cost of activated carbon is low and some activated carbons have good properties and are feasible for use in phosgene synthesis steam generation systems, it is possible to consider providing activated carbon suitable for phosgene synthesis steam generation systems as a catalyst. On the one hand, this can improve the tolerance of activated carbon in the phosgene synthesis process and improve the overall catalyst life and energy utilization of the phosgene synthesis system. On the other hand, it can save modification costs.

[0009] Summary of the Invention

[0010] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0011] The purpose of the present application is to provide an activated carbon catalyst for phosgene synthesis and an application method thereof, and to formulate three characteristic tolerance indexes for phosgene synthesis working conditions to ensure the tolerance performance of the activated carbon that meets the conditions under phosgene synthesis working conditions, so as to enable it to be suitable for phosgene synthesis steam generation system, which not only improves the safe and stable operation level of the device, but also improves the energy utilization efficiency of phosgene synthesis.

[0012] To achieve this goal, this application adopts the following technical solutions:

[0013] In a first aspect, the present application provides an activated carbon catalyst for phosgene synthesis, wherein the tolerance index a of the activated carbon catalyst in phosgene synthesis is in the range of 1.0×10 5 ~4.5×10 7 , the tolerance index d range is 8.5×10 2 ~1.0×10 6, the tolerance index f range is 3.0×10 2 ~3.0×10 5 ;

[0014] The tolerance index a, tolerance index d and tolerance index f are calculated by the following formula: a=0.0253×b 2 +0.00093×(b / c) 2 ; d=0.0032×e 2 +0.00038×(e / c) 2 ; f=0.0012×g 2 +0.00025×(g / c) 2 ;

[0015] 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 aluminum content in the activated carbon catalyst, ppm; g is the iron content in the activated carbon catalyst, ppm.

[0016] The activated carbon catalyst for phosgene synthesis provided in the present application is based on a large number of experiments conducted with the total metal element content, aluminum element content, iron element content and pore volume as specific parameters to determine the corresponding metal element and pore volume ratio relationship when the activated carbon has the best tolerance performance, and obtain tolerance index a, tolerance index d and tolerance index f. By controlling their ranges, the tolerance performance of the activated carbon catalyst in the phosgene synthesis system is effectively improved, and the service life of the activated carbon catalyst is extended; the activated carbon catalyst is suitable for high-temperature operating conditions, so that the cooling medium for phosgene synthesis can select high-boiling point substances without considering the tolerance capacity of the activated carbon.

[0017] The tolerance index a of the activated carbon catalyst in phosgene synthesis is in the range of 1.0×10 5 ~4.5×10 7 , for example, it can 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 , but not limited to the listed values, other values ​​not listed in the numerical range are also applicable, and can be further selected as 5.0×10 5 ~4.0×10 6 .

[0018] The tolerance index d of the activated carbon catalyst in phosgene synthesis is in the range of 8.5×10 2 ~1.0×10 6 , for example, it can 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 , but not limited to the listed values, other values ​​not listed in the numerical range are also applicable, and can be further selected as 2.5×10 3 ~2.5×10 4 .

[0019] The tolerance index f of the activated carbon catalyst in phosgene synthesis is in the range of 3.0×10 2 ~3.0×10 5 , for example, it can 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 , but not limited to the listed values, other values ​​not listed in the numerical range are also applicable, and can be further selected as 1.5×10 3 ~1.2×10 4 .

[0020] In one embodiment, the total content b of metal elements 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 numerical range are also applicable.

[0021] In one embodiment, 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 numerical range are also applicable.

[0022] In one embodiment, 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 numerical range are also applicable.

[0023] In one embodiment, the total iron content g 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 numerical range are also applicable.

[0024] In a second aspect, the present application provides an application method of the activated carbon catalyst as described in the first aspect, the application method comprising the following steps:

[0025] Chlorine and carbon monoxide are mixed and then introduced into a phosgene synthesis reaction device containing an activated carbon catalyst to react and synthesize phosgene.

[0026] The activated carbon catalyst provided in the present application is suitable for high-temperature operating conditions. When used in phosgene synthesis, the tolerance of the activated carbon catalyst in the phosgene synthesis system can be brought into play, so that the cooling medium for phosgene synthesis can select high-boiling point substances without considering the tolerance of the activated carbon catalyst.

[0027] In one embodiment, the molar ratio of chlorine to carbon monoxide is (0.8-1):1, for example, 0.8:1, 0.85:1, 0.93:1, 0.95:1 or 1:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] In one embodiment, the mixing method includes any one or a combination of at least two of pipeline 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 pipeline mixing, nozzle mixing and stirring mixing, or a combination of pipeline mixing, nozzle mixing, stirring mixing and static mixer mixing. The combination of stirring mixing and static mixer mixing can be selected, and static mixer mixing can be further selected.

[0029] In one embodiment, the phosgene synthesis reaction device includes any one of a shell-and-tube reaction tube, a spiral tubular reactor, a fixed bed shell-and-tube reactor or a double-tube plate fixed bed reactor, and can be a fixed bed shell-and-tube reactor.

[0030] In one embodiment, the gauge pressure of the phosgene synthesis reaction device is 0.1-0.5 MPa, for example, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa or 0.5 MPa, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] In one embodiment, the inlet temperature of the phosgene synthesis reaction device is 10 to 60°C, for example, 10°C, 20°C, 30°C, 40°C or 60°C, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, and 20 to 40°C can be selected.

[0032] In one embodiment, the outlet temperature of the phosgene synthesis reaction device is 40 to 350°C, for example, 40°C, 50°C, 60°C, 250°C or 350°C, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, and 50 to 250°C can be selected.

[0033] In the present application, the phosgene synthesis reaction device is provided with a coolant circulation space, in which a coolant circulates to absorb the reaction heat generated by synthesizing phosgene; wherein the coolant circulation space is provided on the shell side of the phosgene synthesis reaction device, specifically the space surrounding the tube array in the phosgene synthesis reaction device.

[0034] 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 of activated carbon treatment.

[0035] As an optional technical solution of the application method described in this application, the application method includes the following steps:

[0036] Chlorine and carbon monoxide are mixed in a molar ratio of (0.8-1.0):1, and then introduced into a phosgene synthesis reaction device containing an activated carbon catalyst for reaction. The phosgene synthesis reaction device 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.

[0037] Compared with the prior art, this application has the following beneficial effects:

[0038] The activated carbon catalyst for phosgene synthesis provided in the present application 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 greater than 3000d. The activated carbon catalyst is suitable for high-temperature operating conditions, so that the cooling medium for phosgene synthesis can select high-boiling-point substances without considering the tolerance capacity of the activated carbon.

[0039] Still other aspects will become apparent upon reading and understanding the detailed description. DETAILED DESCRIPTION

[0040] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0041] Raw materials and sources:

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

[0043] Chlorine (industrial product), produced by the hydrogen chlorine 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 is determined by measuring the amount of nitrogen or carbon dioxide adsorbed on the activated carbon catalyst using a double isotherm NLDFT advanced pore size distribution analyzer.

[0047] Example 1

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

[0049] The tolerance index a, tolerance index d and tolerance index f are calculated by the following formula: a=0.0253×b 2 +0.00093×(b / c) 2 ; d=0.0032×e 2 +0.00038×(e / c) 2 ; f=0.0012×g 2 +0.00025×(g / c) 2 ;

[0050] Among them, the total content of metal elements 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.

[0051] The application method of the activated carbon catalyst for phosgene synthesis comprises the following steps:

[0052] Chlorine and carbon monoxide at a molar ratio of 0.93:1 were mixed in a static mixer and then introduced into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reaction device had a gauge pressure of 0.4 MPa, an inlet temperature of 30°C, and an outlet temperature of 60°C to synthesize phosgene.

[0053] Example 2

[0054] This embodiment provides an activated carbon catalyst for phosgene synthesis. The tolerance index a of the activated carbon catalyst in phosgene synthesis is 4.87×10 5 , the tolerance index d is 5.18×10 3 , the tolerance index f is 2.33×10 3 ;

[0055] The tolerance index a, tolerance index d and tolerance index f are calculated by the following formula: a=0.0253×b 2 +0.00093×(b / c) 2 ; d=0.0032×e 2 +0.00038×(e / c) 2 ; f=0.0012×g 2 +0.00025×(g / c) 2 ;

[0056] Among them, the total content of metal elements b in the activated carbon catalyst is 4356 ppm; the pore volume c of the activated carbon catalyst is 1.64 mL / g; the content of aluminum elements e in the activated carbon catalyst is 1245 ppm; and the content of iron elements g in the activated carbon catalyst is 1343 ppm.

[0057] The application method of the activated carbon catalyst for phosgene synthesis comprises the following steps:

[0058] Chlorine and carbon monoxide at a molar ratio of 0.85:1 were mixed in a static mixer and then introduced into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reaction device had a gauge pressure of 0.2 MPa, an inlet temperature of 20°C, and an outlet temperature of 50°C to synthesize phosgene.

[0059] Example 3

[0060] This embodiment provides an activated carbon catalyst for phosgene synthesis. The tolerance index a of the activated carbon catalyst in phosgene synthesis is 1.28×10 6 , the tolerance index d is 3.05×10 4 , the tolerance index f is 6.31×10 3 ;

[0061] The tolerance index a, tolerance index d and tolerance index f are calculated by the following formula: a=0.0253×b 2 +0.00093×(b / c) 2 ; d=0.0032×e 2 +0.00038×(e / c) 2 ; f=0.0012×g 2 +0.00025×(g / c) 2 ;

[0062] Among them, the total content of metal elements 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 in the activated carbon catalyst is 2950 ppm; and the iron element content g in the activated carbon catalyst is 2124 ppm.

[0063] The application method of the activated carbon catalyst for phosgene synthesis comprises the following steps:

[0064] Chlorine and carbon monoxide at a molar ratio of 0.95:1 were mixed in a static mixer and then introduced into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reaction device had a gauge pressure of 0.3 MPa, an inlet temperature of 40°C, and an outlet temperature of 250°C to synthesize phosgene.

[0065] Example 4

[0066] This embodiment provides an activated carbon catalyst for phosgene synthesis. The tolerance index a of the activated carbon catalyst in phosgene synthesis is 4.78×10 5 , the tolerance index d is 1.07×104 , the tolerance index f is 1.30×10 3 ;

[0067] The tolerance index a, tolerance index d and tolerance index f are calculated by the following formula: a=0.0253×b 2 +0.00093×(b / c) 2 ; d=0.0032×e 2 +0.00038×(e / c) 2 ; f=0.0012×g 2 +0.00025×(g / c) 2 ;

[0068] Among them, the total content of metal elements 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.

[0069] The application method of the activated carbon catalyst for phosgene synthesis comprises the following steps:

[0070] Chlorine and carbon monoxide at a molar ratio of 0.8:1 were stirred and mixed in a static mixer, and then introduced into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The gauge pressure of the phosgene synthesis reaction device was 0.1 MPa, the inlet temperature was 10°C, and the outlet temperature was 40°C to synthesize phosgene.

[0071] Example 5

[0072] This embodiment provides an activated carbon catalyst for phosgene synthesis, wherein the tolerance index a of the activated carbon catalyst in phosgene synthesis is 1.50×10 6 , the tolerance index d is 3.05×10 4 , the tolerance index f is 1.26×10 4 ;

[0073] The tolerance index a, tolerance index d and tolerance index f are calculated by the following formula: a=0.0253×b 2 +0.00093×(b / c) 2 ; d=0.0032×e 2 +0.00038×(e / c) 2 ; f=0.0012×g 2 +0.00025×(g / c) 2 ;

[0074] Among them, the total content of metal elements 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.

[0075] The application method of the activated carbon catalyst for phosgene synthesis comprises the following steps:

[0076] Chlorine and carbon monoxide in a molar ratio of 1:1 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 gauge pressure of the phosgene synthesis reaction device is 0.5 MPa, the inlet temperature is 60°C, and the outlet temperature is 350°C to synthesize phosgene.

[0077] Example 6

[0078] This embodiment provides an activated carbon catalyst for phosgene synthesis. The tolerance index a of the activated carbon catalyst in phosgene synthesis is 4.12×10 6 , the tolerance index d is 2.87×10 4 , the tolerance index f is 1.29×10 4 ;

[0079] The tolerance index a, tolerance index d and tolerance index f are calculated by the following formula: a=0.0253×b 2 +0.00093×(b / c) 2 ; d=0.0032×e 2 +0.00038×(e / c) 2 ; f=0.0012×g 2 +0.00025×(g / c) 2 ;

[0080] Among them, the total content of metal elements 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.

[0081] The application method of the activated carbon catalyst for phosgene synthesis comprises the following steps:

[0082] Chlorine and carbon monoxide at a molar ratio of 0.93:1 were mixed in a static mixer and then introduced into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reaction device had a gauge pressure of 0.4 MPa, an inlet temperature of 30°C, and an outlet temperature of 60°C to synthesize phosgene.

[0083] Example 7

[0084] This embodiment provides an activated carbon catalyst for phosgene synthesis. The tolerance index a of the activated carbon catalyst in phosgene synthesis is 4.63×10 5 , the tolerance index d is 1.49×10 3 , the tolerance index f is 1.17×10 3 ;

[0085] The tolerance index a, tolerance index d and tolerance index f are calculated by the following formula: a=0.0253×b 2 +0.00093×(b / c) 2 ; d=0.0032×e 2 +0.00038×(e / c) 2 ; f=0.0012×g 2 +0.00025×(g / c) 2 ;

[0086] Among them, the total content of metal elements 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.

[0087] The application method of the activated carbon catalyst for phosgene synthesis comprises the following steps:

[0088] Chlorine and carbon monoxide at a molar ratio of 0.93:1 were mixed in a static mixer and then introduced into a fixed-bed tubular reactor containing an activated carbon catalyst for reaction. The phosgene synthesis reaction device had a gauge pressure of 0.4 MPa, an inlet temperature of 30°C, and an outlet temperature of 60°C to synthesize phosgene.

[0089] Comparative Example 1

[0090] 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 element content e, and iron element content g in the activated carbon catalyst are adjusted, and the adaptability tolerance index a is 9.14×10 4 , the tolerance index d is 1.86×10 2 , the tolerance index f is 2.78×10 2 , the rest are the same as in Example 1.

[0091] Comparative Example 2

[0092] 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 element content e, and iron element content g in the activated carbon catalyst are adjusted, and the adaptability tolerance index a is 6.82×10 7 , the tolerance index d is 3.23×10 6 , the tolerance index f is 7.17×10 5 , the rest are the same as in Example 1.

[0093] Comparative Example 3

[0094] 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 element content e, and iron element content g in the activated carbon catalyst are adjusted, and the adaptability tolerance index a is 9.14×10 4 , the tolerance index d is 2.23×10 2 , the tolerance index f is 3.58×10 3 , the rest are the same as in Example 1.

[0095] Comparative Example 4

[0096] 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 element content e, and iron element content g in the activated carbon catalyst are adjusted, and the adaptability tolerance index a is 1.24×10 8 , the tolerance index d is 1.76×10 4 , the tolerance index f is 7.74×10 4 , the rest are the same as in Example 1.

[0097] 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.

[0098] Table 1

[0099] As can be seen from Table 1, by using the activated carbon catalyst provided by the present application to synthesize phosgene, the tolerance performance of the activated carbon catalyst under phosgene synthesis conditions can be effectively improved by precisely controlling the three characteristic tolerance indices, thereby increasing the operating cycle.

[0100] By comparing Example 1 with Comparative Examples 1-4, it can be seen that the tolerance index a, tolerance index d and tolerance index f all exceed the specified range, which will significantly reduce the tolerance performance of the activated carbon catalyst, thereby increasing the annual quality loss and shortening the operating cycle; if only one or two tolerance indices exceed the specified range, the tolerance performance of the activated carbon catalyst will also be reduced, and the operating cycle will be shortened.

[0101] In summary, the activated carbon catalyst for phosgene synthesis provided in the present application 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 greater than 3000d; the activated carbon catalyst is suitable for high-temperature operating conditions, so that the cooling medium for phosgene synthesis can select high-boiling point substances without considering the tolerance capacity of the activated carbon.

[0102] The above description is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Those skilled in the art should understand that any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application fall within the protection scope and disclosure scope of the present application.

Claims

1. An activated carbon catalyst for phosgene synthesis, with the tolerance index a in the range of 1.0×10 5 ~4.5×10 7 , the tolerance index d in the range of 8.5×10 2 ~1.0×10 6 , and the tolerance index f in the range of 3.0×10 2 ~3.0×10 5 ; The tolerance indices a, d, and f are calculated by the following formulas: a = 0.0253×b 2 + 0.00093×(b / c) 2 ; d = 0.0032×e 2 + 0.00038×(e / c) 2 ; f = 0.0012×g 2 + 0.00025×(g / c) 2 ; Among them, b is the total metal element content in the activated carbon catalyst, in ppm; c is the pore volume of the activated carbon catalyst, in mL / g; e is the aluminum element content in the activated carbon catalyst, in ppm; g is the iron element content in the activated carbon catalyst, in ppm.

2. The activated carbon catalyst according to claim 1, wherein, The tolerance index a of the activated carbon catalyst in phosgene synthesis ranges from 5.0×10 5 to 4.0×10 6 .

3. The activated carbon catalyst according to claim 1 or 2, wherein The tolerance index d of the activated carbon catalyst in phosgene synthesis ranges from 2.5×10 3 to 2.5×10 4 .

4. The activated carbon catalyst according to any one of claims 1 to 3, wherein, The tolerance index f of the activated carbon catalyst in phosgene synthesis ranges from 1.5×10 3 to 1.2×10 4 .

5. The activated carbon catalyst according to any one of claims 1 to 4, wherein, The total metal element content b in the activated carbon catalyst is 1500 - 21000 ppm; Optionally, the pore volume c of the activated carbon catalyst is 0.1 - 3.0 mL / g; Optionally, the total aluminum element content e in the activated carbon catalyst is 500 - 6000 ppm; Optionally, the total iron element content g in the activated carbon catalyst is 500 - 4000 ppm.

6. A method for applying the activated carbon catalyst according to any one of claims 1 - 5, comprising the following steps: Mix chlorine gas and carbon monoxide, and then introduce them into a phosgene synthesis reaction device containing the activated carbon catalyst for reaction to synthesize phosgene.

7. The application method according to claim 6, wherein, The molar ratio of the chlorine gas to the carbon monoxide is (0.8 - 1):

1.

8. The application method according to claim 6 or 7, wherein The mixing method includes any one or a combination of at least two of pipeline mixing, nozzle mixing, stirring mixing, or static mixer mixing; Optionally, the phosgene synthesis reaction device includes any one of a shell - and - tube reaction tube, a spiral - tube reactor, a fixed - bed shell - and - tube reactor, or a double - tube - plate fixed - bed reactor.

9. The application method according to any one of claims 6-8, wherein, The phosgene synthesis reaction device is a fixed - bed shell - and - tube reactor.

10. The application method according to any one of claims 6 to 9, wherein, The gauge pressure of the phosgene synthesis reaction device is 0.1 - 0.5 MPa; Optionally, the inlet temperature of the phosgene synthesis reaction device is 10 - 60 °C, and further optionally 20 - 40 °C; Optionally, the outlet temperature of the phosgene synthesis reaction device is 40 - 350 °C, and further optionally 50 - 250 °C.

11. According to the application method described in any one of claims 6 to 10, wherein, The application method includes the following steps: Mix chlorine gas and carbon monoxide with a molar ratio of (0.8 - 1.0):1, and then introduce them into a phosgene synthesis reaction device containing the activated carbon catalyst for reaction. The gauge pressure of the phosgene synthesis reaction device is 0.1 - 0.5 MPa, the inlet temperature is 10 - 60 °C, and the outlet temperature is 40 - 350 °C to synthesize phosgene.

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