A catalyst for synthesizing ethylenediamine by ethylene dichloride method, a preparation method thereof, and a method for synthesizing ethylenediamine by using the catalyst

Abstract

The present invention belongs to the field of ethylene dichloride method synthesis of ethylene diamine, in particular to a catalyst for ethylene dichloride method synthesis of ethylene diamine and a preparation method thereof and a method for synthesizing ethylene diamine using the catalyst. The catalyst is composed of the following components in weight percentage: 28-34% of metal active components, and the remaining components are oxygen elements and skeleton silicon dioxide that match the metal active components; the metal active components are composed of Co, lanthanide metals, and additional metals; the total mass of Co and lanthanide metals accounts for 83%-88% of the total weight of the metal active components, and the additional metals account for 12-17% of the total amount of the catalyst active components. The present invention is composed of Co, lanthanide metals, and additional metals to form metal active components, and the catalyst is composited with a carrier to form a catalyst. By optimizing the combination of active metal elements and the ratio between active metal elements, the amount of metal active components in the catalyst is reduced, and the selectivity of catalyzing the synthesis of ethylene dichloride method is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of synthesizing ethylenediamine by ethylene dichloride method, and specifically relates to a catalyst used for synthesizing ethylenediamine by ethylene dichloride method, a preparation method thereof and a method for synthesizing ethylenediamine by using the catalyst. Background Art

[0002] Ethylenediamine is an important chemical intermediate. At present, the methods for synthesizing ethylenediamine include the ethylene dichloride method, the ethanolamine method, the ethylene amination method, the diethylene glycol amination method, etc., and the ethylene dichloride method and the ethanolamine method are the main methods in industry. The proportion of ethylene dichloride method used to synthesize ethylenediamine in the world is close to 60%, which has the advantages of easy raw material availability, fast reaction speed, and by-products of high value-added products such as polyethylene polyamines and piperazine.

[0003] All the processes for synthesizing ethylenediamine from dichloroethane at home and abroad are mostly non-catalytic processes, and the single-pass yield of ethylenediamine is 40-70%. There are few studies and reports on the method of synthesizing ethylenediamine from dichloroethane under catalysis. For example, Chinese patent CN201110040741.9 uses a combination of transition metal elements as raw materials to synthesize catalysts, and applies them to the process of synthesizing ethylenediamine from dichloroethane, which can effectively improve the yield of ethylenediamine, shorten the reaction cycle, reduce material consumption, reduce environmental pollution, and the reaction conditions are milder and safer.

[0004] In order to further improve the yield of ethylenediamine synthesized by the ethylene dichloride method and reduce the process difficulty and cost, researchers have been exploring more efficient and cheap catalysts. Summary of the invention

[0005] The object of the present invention is to provide a catalyst for synthesizing ethylenediamine by ethylene dichloride method and a preparation method thereof, so as to improve the selectivity of synthesizing ethylenediamine by ethylene dichloride method and reduce the process difficulty and cost.

[0006] The technical solution for achieving the purpose of the present invention is as follows:

[0007] A catalyst for synthesizing ethylenediamine by ethylene dichloride method, the catalyst is composed of the following components in weight percentage: 28-34% of metal active component, and the remaining components are oxygen elements and skeleton silicon dioxide matching the metal active component.

[0008] Furthermore, the metal active component is composed of Co, lanthanide metal and additional metal, wherein the total weight of Co and lanthanide metal accounts for 83%-88% of the total weight of the metal active component, and the additional metal accounts for 12-17% of the total weight of the metal active component.

[0009] Furthermore, the lanthanide metal includes at least one of Pr, Eu, Gd, Tb, Er, Yb, and Y.

[0010] Furthermore, the additional metal includes one or two of Rh, Ru, Ba, Mg, Sn, Zn, and Mn.

[0011] Furthermore, the metal atomic ratio of Co to lanthanide metal is 5-7:1.

[0012] Preferably, the additional metal includes two of Rh, Ru, Ba, Mg, Sn, Zn and Mn, and the atomic ratio of the two metals is 1:3-5.

[0013] The preparation method of the catalyst for synthesizing ethylenediamine by the ethylene dichloride method comprises the following steps:

[0014] ⑴ Weigh soluble metal salts and prepare metal salt working solutions with a molar content of 0.008-0.015M, place them in respective measuring bottles, and prepare alkaline precipitant solution and place it in a measuring bottle;

[0015] ⑵ Add pure water to the reaction tank, heat to 95-99°C under stirring, add metal working liquid in multiple streams, stir at 280-300 rpm, slowly add alkaline precipitant according to the isoelectric point of complete precipitation of metal salt in the raw material, control the flow of alkaline precipitant, adopt stepwise PH swing method to achieve metal precipitation, PH swing is repeated 5-8 times, acid side PH = 3.8, alkaline side = 10.3, reaction end PH = 3.8-4.0, overall time 170-180 minutes, and at the same time control the solid content of the colloid system by adding water to 0.5-2.0g / L. After the reaction, the whole system is crystallized at 120-150°C for 36 hours, and then the PH is adjusted to 7.8-8.0, and then crystallized at 120-150°C for 36 hours, filtered to obtain filter cake, and the filter cake is washed with pure water several times until the conductivity of the washing water is ≯10μs / cm;

[0016] ⑶ The qualified filter cake obtained after washing in step ⑵ is mixed with the carrier silica by adding water to adjust to a slurry, the solid content is controlled at 1.0-5.0%, 880-900 rpm, slurrying for 55-60 minutes, and adjusting the pH to 4.8-6.0;

[0017] (4) Add a binder methyl cellulose aqueous solution to the above mixed slurry to ensure that the final weight concentration of the binder in the system is 0.05-0.06%, seal the dispersion tank, connect compressed air, control the flow rate to 60-100mL / min, input the slurry into the fluidized bed, dehydrate and oxidize in the fluidized bed boiling state at 600-650℃ to obtain a powdered catalyst.

[0018] Furthermore, the soluble metal salt in step (1) includes soluble metal nitrate, soluble metal hydrochloride, soluble sulfate or soluble metal acetate.

[0019] Furthermore, the alkaline precipitant solution in step (2) is an aqueous solution of sodium hydroxide, sodium carbonate, ammonium hydroxide, triethylamine or n-butylamine.

[0020] Furthermore, the carrier silica in step (3) is added in the form of silica sol or ethyl silicate; silica sol is a weakly acidic amorphous colloidal liquid with a silica content of 25-30% and a specific gravity of 1.15-1.19 g / cm 3 Ethyl silicate is a weakly acidic organic silica sol with a silicon dioxide content of 28-30% and a specific gravity of 0.93-0.94 g / cm 3 .

[0021] Furthermore, the binder in step (4) is an aqueous solution of methyl cellulose, hydroxy cellulose or polyvinyl alcohol.

[0022] The use of the above catalyst in catalyzing the synthesis of ethylenediamine from ethylene dichloride comprises the following steps:

[0023] ⑴ Weigh the catalyst and add it to the internal circulation flow reactor, seal the reactor, add water, replace with inert gas, heat to 180-190°C under stirring, introduce H2+N2 mixed gas, control the system pressure not to exceed 0.6Mpa, react for 160-200 minutes, and then cool to room temperature;

[0024] (2) Add liquid ammonia to make the concentration of ammonia water in the reactor 35%, and heat it to 90-100°C;

[0025] ⑶ Add dichloroethane so that the molecular ratio of liquid ammonia to dichloroethane is 1.2-2.6:1, and control the reaction temperature to 98-108°C. After the addition of dichloroethane is completed, control the temperature of the reaction system to 106-110°C, maintain for 15-25 minutes, and cool down to complete the reaction process.

[0026] Furthermore, the weight of the catalyst is 1.5-5.5% of the weight of the ethylene dichloride raw material.

[0027] The beneficial effects of the present invention are:

[0028] The present invention comprises Co, lanthanide metals and additional metals as metal active components, which are compounded with a carrier to form a catalyst. By optimizing the combination of active metal elements and the ratio between the active metal elements, the amount of metal active components in the catalyst is reduced, and the yield of synthesizing ethylenediamine from dichloroethane is improved (more than 77%). DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the embodiments. The following embodiments are illustrative rather than restrictive, and the protection scope of the present invention cannot be limited by the following embodiments.

[0030] Embodiment 1:

[0031] The catalyst of this embodiment is composed of the following components in weight percentage: 30% of metal active components, and the remaining components are oxygen elements and framework silicon dioxide that match the metal active components; the total mass of Co and lanthanide metal Tb in the metal active components accounts for 85% of the total weight of the metal active components, and the metal atomic ratio of Co and lanthanide metal Tb is 6:1; the additional metal accounts for 15% of the total amount of the catalyst active components, and the atomic ratio of Ru and Ba in the additional metal is 1:3; the specific steps are as follows:

[0032] (1) Preparation of metal working solution: Accurately weigh the required soluble metal salts (cobalt nitrate hexahydrate, terbium nitrate hexahydrate, ruthenium acetate, palladium nitrate) respectively, prepare them into a 0.008M aqueous solution of the equivalent metal concentration, and place them in respective measuring bottles;

[0033] (2) Alkali precipitant preparation: Prepare an aqueous solution of 8% by weight of sodium carbonate and place it in a measuring bottle;

[0034] (3) Measure the reaction base water according to the synthesis weight of the catalyst, measure 1000 ml of pure water and add it to the reaction tank, heat it to 95-99° C. under stirring, add multiple streams of metal working liquid in parallel according to the required ratio, make the stirring speed 280-300 rpm, slowly add the alkali precipitant according to the isoelectric point of complete precipitation of the metal salt in the raw material, control the flow rate of the alkali precipitant, adopt the stepwise pH swing method to achieve metal precipitation, repeat the pH swing 6 times, the acid side pH ≈ 3.8, the alkaline side ≈ 10.3, the reaction end pH ≈ 3.8-4.0, the overall time is 170-180 minutes, and at the same time, control the solid content of the colloidal system by adding water to 0.5-2.0 g / L. After the reaction is completed, the whole system is crystallized at 120-150° C. for 36 hours, and then the pH is adjusted to 7.8-8.0, and then crystallized at 120-150° C. for 36 hours, filtered, and washed with pure water until the conductivity of the washing water is ≯10μs / cm;

[0035] (4) The filter cake obtained in step (3) and 215 ml of ethyl silicate solution were mixed by adding water, the solid content of the slurry was adjusted to 1.0-5.0 g / L, slurried at 880-900 rpm for 55-60 minutes, and the pH was adjusted to 4.8-6.0;

[0036] The silicon dioxide content in the ethyl silicate solution is 28%, and the specific gravity is 0.93g / cm 3 .

[0037] (5) Add a binder methyl cellulose aqueous solution to the mixed slurry to ensure that the final weight concentration of methyl cellulose in the system is 0.05-0.06%, seal the dispersion tank, connect compressed air, control the flow rate to 80 mL / min, input the slurry into the fluidized bed, dehydrate and oxidize in the fluidized bed boiling state at 600-650° C., and contact time 35-38 min to obtain a catalyst.

[0038] Example 2

[0039] The difference between Example 2 and Example 1 is that the atomic ratio of Sn to Zn in the additional metal in the metal active component is 1:3, and the rest is the same as Example 1.

[0040] Example 3

[0041] The difference between Example 3 and Example 1 is that the atomic ratio of Ru to Mn in the additional metal in the metal active component is 1:3, and the rest is the same as Example 1.

[0042] Example 4

[0043] The difference between Example 4 and Example 2 is that the lanthanide metal Tb is replaced by the lanthanide metal Pr, and the rest is the same as Example 1.

[0044] Example 5

[0045] The difference between Example 5 and Example 2 is that the lanthanide metal Tb is replaced by the lanthanide metal Eu, and the rest is the same as Example 1.

[0046] Example 6

[0047] The difference between Example 6 and Example 2 is that the lanthanide metal Tb is replaced by the lanthanide metal Gd, and the rest is the same as Example 1.

[0048] Example 7

[0049] The difference between Example 7 and Example 2 is that the lanthanide metal Tb is replaced by the lanthanide metal Yb, and the rest is the same as Example 1.

[0050] Example 8

[0051] The difference between Example 8 and Example 7 is that the mass percentage of the metal active component in the catalyst is 28%, and the rest is the same as Example 7.

[0052] Example 9

[0053] The difference between Example 9 and Example 7 is that the mass percentage of the metal active component in the catalyst is 34%, and the rest is the same as Example 7.

[0054] Example 10

[0055] The catalyst of this embodiment is composed of the following components in weight percentage: 28% metal active component, and the remaining components are oxygen elements and framework silicon dioxide that match the metal active component; the total mass of Co and lanthanide metal Y in the metal active component accounts for 88% of the total weight of the metal active component, and the metal atomic ratio of Co and lanthanide metal Y is 5:1; the additional metal accounts for 12% of the total amount of the catalyst active component, and the atomic ratio of Ba and Mg in the additional metal is 1:4; the preparation method is the same as that in Example 1.

[0056] Embodiment 11

[0057] The catalyst of this embodiment is composed of the following components in weight percentage: 34% metal active component, and the remaining components are oxygen elements and skeleton silica that match the metal active component; the total mass of Co and lanthanide metal Er in the metal active component accounts for 83% of the total weight of the metal active component, and the metal atomic ratio of Co and lanthanide metal Er is 7:1; the additional metal accounts for 17% of the total amount of the catalyst active component, and the atomic ratio of Rh and Mn in the additional metal is 1:5; the preparation method is the same as that in Example 1.

[0058] The catalyst prepared in the above example is applied to synthesize ethylenediamine by the ethylene dichloride method, and the steps are as follows:

[0059] (1) accurately weighing the above powdered catalyst in a ratio of 3% of the weight of the ethylene dichloride material in the reaction process and adding it to an internal circulation flow reactor, sealing the reactor, adding accurately measured pure water under pressure, replacing it with inert gas, heating it to 185° C. under stirring, and then introducing a (H2+N2) mixed gas, controlling the system pressure not to exceed 0.6 MPa, reacting for 180 minutes, and then cooling it to room temperature with cooling water;

[0060] (2) Add a calculated amount of liquid ammonia under pressure to make the ammonia concentration in the reactor 35%, and heat to 95°C.

[0061] (3) Industrial dichloroethane was slowly added using a high-pressure metering pump to make the liquid ammonia / dichloroethane molecular ratio 2.3, and the reaction temperature was controlled at 98-108°C. After the addition of industrial dichloroethane was completed, the temperature of the reaction system was controlled at 108±2°C and maintained for about 20 minutes. The temperature was lowered to complete the reaction. The reaction results are shown in Table 1.

[0062] Comparative Example 1

[0063] The difference between Comparative Example 1 and Example 1 is that the atomic ratio of Ru to Ba in the additional metal is 1:1.5, and the rest is the same as Example 1.

[0064] Table 1 Results of synthesizing ethylenediamine from ethylene dichloride catalyzed by the catalyst prepared in Example

[0065]

[0066]

[0067] Note: The conversion rate of dichloroethane is determined by chemical titration to detect the content of dichloroethane in the system before and after the reaction. The detection of ethylenediamine is carried out by chromatography.

[0068] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A catalyst for synthesizing ethylenediamine by the ethylene dichloride process, characterized in that: The catalyst is composed of the following components in weight percentage: 28-34% of metal active component, and the remaining components are oxygen elements and framework silicon dioxide that match the metal active component; The metal active component is composed of Co, lanthanide metal and additional metal, wherein the total weight of Co and lanthanide metal accounts for 83%-88% of the total weight of the metal active component, and the additional metal accounts for 12-17% of the total weight of the metal active component; The lanthanide metal includes at least one of Pr, Eu, Gd, Tb, Er, Yb, and Y; The additional metals include two of Rh, Ru, Re, Ba, Mg, Sn, and Zn, and the atomic ratio of the two metals is 1:3-5.

2. The catalyst for synthesizing ethylenediamine by the ethylene dichloride process according to claim 1, characterized in that: The metal atomic ratio of Co and lanthanide metal is 5-7:

1.

3. A method for preparing a catalyst for synthesizing ethylenediamine by ethylene dichloride method according to any one of claims 1 to 2, characterized in that: The following steps are involved: ⑴ Weigh the required soluble metal salts, prepare metal salt working solutions with a molar content of 0.008-0.015M, place them in their respective measuring bottles, and prepare alkaline precipitant solutions in measuring bottles; ⑵ Add pure water to the reaction tank, heat to 95-99°C under stirring, add metal working liquid in multiple streams, stir at 280-300 rpm, slowly add alkaline precipitant according to the isoelectric point of complete precipitation of metal salt in the raw material, control the flow of alkaline precipitant, adopt stepwise PH swing method to achieve metal precipitation, PH swing is repeated 5-8 times, acid side PH = 3.8, alkaline side = 10.3, reaction end PH = 3.8-4.0, overall time 170-180 minutes, and at the same time control the solid content of the colloid system by adding water to 0.5-2.0g / L. After the reaction is completed, the whole system is crystallized at 120-150°C for 36 hours, and then the PH is adjusted to 7.8-8.0, and then crystallized at 120-150°C for 36 hours, filtered to obtain filter cake, and the filter cake is washed with pure water several times until the conductivity of the washing water is ≯10μs / cm; ⑶ The qualified filter cake obtained after washing in step ⑵ is mixed with the carrier silica by adding water to adjust to a slurry, the solid content is controlled at 1.0-5.0%, 880-900 rpm, slurrying for 55-60 minutes, and adjusting the pH to 4.8-6.0; (4) Add a binder methyl cellulose aqueous solution to the above mixed slurry to ensure that the final weight concentration of methyl cellulose in the system is 0.05-0.06%, seal the dispersion tank, connect compressed air, control the flow rate to 60-100mL / min, input the slurry into the fluidized bed, dehydrate and oxidize in the fluidized bed boiling state at 600-650℃ to obtain a powdered catalyst.

4. The method for preparing a catalyst for synthesizing ethylenediamine by ethylene dichloride method according to claim 3, characterized in that: The carrier silica is added in the form of silica sol or ethyl silicate.

5. The method for preparing a catalyst for synthesizing ethylenediamine by ethylene dichloride method according to claim 3, characterized in that: The soluble metal salt includes soluble metal nitrate, soluble metal hydrochloride, soluble metal sulfate or soluble metal acetate.

6. The method for preparing a catalyst for synthesizing ethylenediamine by ethylene dichloride method according to claim 3, characterized in that: The alkaline precipitant is one of an aqueous solution of sodium hydroxide, sodium carbonate, ammonium hydroxide, triethylamine or n-butylamine; The binder is one of methyl cellulose, hydroxy cellulose or an aqueous solution of polyvinyl alcohol.

7. Use of the catalyst according to any one of claims 1-2 in catalyzing the synthesis of ethylenediamine from ethylene dichloride, characterized in that: The following steps are involved: ⑴ Weigh the catalyst and add it to the internal circulation flow reactor, seal the reactor, add water, replace with inert gas, heat to 180-190°C under stirring, introduce H2+N2 mixed gas, control the system pressure not to exceed 0.6Mpa, react for 160-200 minutes, and then cool to room temperature; (2) Add liquid ammonia to make the concentration of ammonia water in the reactor 35%, and heat it to 90-100°C; ⑶ Add dichloroethane so that the molecular ratio of liquid ammonia to dichloroethane is 1.2-2.6:1, and control the reaction temperature to 98-108°C. After the addition of dichloroethane is completed, control the temperature of the reaction system to 106-110°C, maintain for 15-25 minutes, and cool down to complete the reaction process.

8. The use according to claim 7, characterized in that: The weight of the catalyst is 1.5-5.5% of the weight of the ethylene dichloride raw material.

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