Catalyst for preparing 1, 1, 2, 3-tetrachloropropene as well as preparation method and application thereof

Abstract

The invention discloses a catalyst for preparing 1, 1, 2, 3-tetrachloropropene, the catalyst is composed of a spherical Al2O3 carrier, a noble metal M1 and an auxiliary metal M2, the noble metal M1 and the auxiliary metal M2 are loaded on the carrier, the M1 is any one of Pd, Pt or Ru, and the M2 is any one of Mg, Ga, Ba, Fe, Co or Ni; the catalyst comprises the following components in percentage by weight: 0.2 to 3 percent of metal M1, 10 to 30 percent of metal M2 and the balance of carrier. Meanwhile, the invention also discloses a preparation method and application of the catalyst. The catalyst can be used for continuously synthesizing 1, 1, 2, 3-tetrachloropropene by taking 1, 1, 1, 2, 3-pentachloropropane as a raw material, and the product is high in selectivity and good in stability.

Description

Technical Field

[0001] The invention belongs to the technical field of 1,1,2,3-tetrachloropropylene synthesis, and particularly relates to a catalyst for preparing 1,1,2,3-tetrachloropropylene, and a preparation method and application thereof. Background Art

[0002] 1,1,2,3-Tetrachloropropene (HCC-1230xa), with the chemical formula C3H2Cl4, is an important chemical intermediate, mainly used to prepare the chemical herbicide chlormequat and the plant growth regulator chlormequat. In addition, 1,1,2,3-Tetrachloropropene is also an important precursor for the production of the new green and environmentally friendly refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf). At present, the global demand for 1,1,2,3-Tetrachloropropene is constantly increasing, and it has become one of the main hotspots of attention and investment in related industries.

[0003] There are several main methods for synthesizing 1,1,2,3-tetrachloropropene: (1) using carbon tetrachloride and ethylene as raw materials to synthesize 1,1,1,3-tetrachloropropane, 1,1,1,3-tetrachloropropane undergoes a dehydrochlorination-propenyl rearrangement reaction to generate 1,1,3-trichloropropene, 1,1,3-trichloropropene undergoes a chlorination reaction to obtain 1,1,1,2,3-pentachloropropane, and 1,1,1,2,3-pentachloropropane is finally dehydrochlorinated-isomerized to generate the target product 1,1,2,3-tetrachloropropene; (2) using 1,2,3-trichloropropane as a raw material to generate a mixture of 1,1,1,2,3-pentachloropropane and 1,1,2,2,3-pentachloropropane through a chlorination reaction, and the above mixture is dehydrochlorinated-isomerized to generate the target product 1,1,2,3-tetrachloropropene. The above two methods mainly have the problems of long synthesis route, high energy consumption and high separation and purification cost; (3) Directly using 1,1,1,2,3-pentachloropropane as raw material, dehydrochlorination reaction is carried out under liquid or gas phase conditions to generate the target product. The liquid phase reaction mainly faces the problems of long reaction time and complicated waste liquid treatment, while the gas phase reaction mainly faces the problems of poor selectivity of the target product, harsh reaction conditions, and easy carbon deposition and deactivation of the catalyst. In summary, it is still necessary to develop an efficient, stable, green and economical process for 1,1,2,3-tetrachloropropene. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the present invention mainly provides a catalyst for synthesizing 1,1,2,3-tetrachloropropene and a preparation method and application thereof. The catalyst can continuously synthesize 1,1,2,3-tetrachloropropene using 1,1,1,2,3-pentachloropropane as a raw material, and the product has high selectivity and good stability.

[0005] A catalyst for preparing 1,1,2,3-tetrachloropropylene, the catalyst comprising a spherical Al2O3 carrier, a noble metal M1 and an auxiliary metal M2 loaded on the carrier, the M1 being any one of Pd, Pt or Ru, and the M2 being any one of Mg, Ga, Ba, Fe, Co or Ni; the weight of the catalyst being 100%, the contents of the components are as follows: 0.2-3% of the metal M1, 10-30% of the metal M2, and the remainder being the carrier; the catalyst is recorded as M1M2 / Al2O3; Preferably, the M1 is any one of Pd and Ru.

[0006] Preferably, M2 is any one of Fe, Co and Ni.

[0007] Preferably, based on 100% by weight of the catalyst, the content of the metal M1 is 0.2-1%; more preferably, the content of the metal M1 is 0.5-1%.

[0008] The method for preparing the catalyst for preparing 1,1,2,3-tetrachloropropylene comprises the following steps: (1) Add aluminum powder to a dilute hydrochloric acid solution or a crystalline aluminum chloride solution, dissolve the aluminum powder at 80-110°C to form an aluminum sol with a Tyndall effect; (2) adding soluble precursor salts of M1 and M2 and an organic amine to the aluminum sol; (3) dropping into an oil column at 70-110° C. to form the oil column, separating the formed small balls, aging, washing, drying, and then calcining in a mixed atmosphere of either hydrogen or hydrogen chloride and nitrogen to obtain the catalyst.

[0009] Preferably, in the aluminum sol in step (1), the aluminum content is 4-20 wt% and the Al / Cl mass ratio is 0.3-3; the concentration of the dilute hydrochloric acid solution is 5-20 wt%, and the concentration of the crystalline aluminum chloride solution is 10-20 wt%.

[0010] More preferably, the Al / Cl mass ratio is 1-3.

[0011] Preferably, the organic amine is any one of hexamethylenetetramine and urea, and the mass ratio of Al to the organic amine in the aluminum sol is 0.8-10.

[0012] Preferably, the aging condition is aging at 100-180° C. for 5-20 h.

[0013] More preferably, the aging condition is aging at 100-130° C. for 5-20 h.

[0014] Preferably, the volume fraction of hydrogen or hydrogen chloride in the mixed gas is 5-20%, and the flow rate of the mixed atmosphere is 50-500 mL / min.

[0015] Preferably, the drying is carried out at 50-150° C. for 5-20 h; the roasting condition is carried out at 400-800° C. for 3-10 h; and the oil in the oil column is one of vacuum pump oil and edible oil.

[0016] A method for catalyzing 1,1,1,2,3-pentachloropropane to synthesize 1,1,2,3-tetrachloropropene, comprising: loading the catalyst of the present invention into a quartz tube of a fixed bed reactor, introducing 1,1,1,2,3-pentachloropropane to carry out a dehydrochlorination reaction, wherein the reaction temperature is 200-250°C, the reaction pressure is 0.1-1 Mpa, and the mass space velocity is 0.1-0.5 h -1 , collect the reaction products.

[0017] Advantages of the present invention: (1) The present invention adopts the strategy of oil column molding-in-situ growth to prepare the M1M2 / Al2O3 catalyst. The spherical Al2O3 has a high specific surface area and pore volume, which is conducive to the adsorption and diffusion of reactant molecules. There is a strong interaction between the precious metal M1 and the carrier alumina spheres, which can effectively avoid the agglomeration or migration of active components. The auxiliary metal M2 can effectively inhibit the acid sites on the carrier surface, thereby improving the deactivation phenomenon of the catalyst caused by carbon deposition; (2) The M1M2 / Al2O3 catalyst provided by the present invention can be used for the continuous synthesis of 1,1,1,2,3-pentachloropropane into 1,1,2,3-tetrachloropropene. It has high catalytic activity and target product yield. The catalyst has long-term usability, high process automation, low labor intensity, low equipment investment, good economic and social benefits, and can provide technical support for later industrial production. DETAILED DESCRIPTION

[0018] Example 1 A catalyst for preparing 1,1,2,3-tetrachloropropylene, the catalyst comprising a spherical Al2O3 carrier, a precious metal Pd and an auxiliary metal Fe loaded on the carrier, wherein the weight of the catalyst is 100%, and the content of each component is as follows: Pd 1.0%, Fe 10.0%, and the balance is the carrier; The preparation method of the catalyst is as follows: (1) 50.0 g of aluminum powder was added to 1000.0 g of a 5 wt% dilute hydrochloric acid solution, and the aluminum powder was dissolved at 110°C to form an aluminum sol having a Tyndall effect; (2) adding 2.9 g Na2PdCl4, 62.9 g FeCl3·6H2O and 60.0 g hexamethylenetetramine to the aluminum sol, and mixing and dissolving them thoroughly; (3) The mixture of step (2) was dripped into 70°C vacuum pump oil for oil column molding, and the molded pellets were separated and aged at 130°C for 5h, then washed with pure water and dried at 140°C for 10h, and finally calcined at 400°C for 5h in a mixed atmosphere of 100 mL / min and 10% H2 / N2 to obtain the catalyst.

[0019] Example 2 A catalyst for preparing 1,1,2,3-tetrachloropropylene, the catalyst comprising a spherical Al2O3 carrier, a precious metal Pd and an auxiliary metal Co loaded on the carrier, wherein the weight of the catalyst is calculated as 100%, and the contents of each component are as follows: Pd 0.5%, Co 20.0%, and the balance being the carrier; In the preparation method, the precursor salt of Co is CoCl2·6H2O, and the rest is the same as in Example 1.

[0020] Same as Example 1.

[0021] Example 3 A catalyst for preparing 1,1,2,3-tetrachloropropylene, the catalyst comprising a spherical Al2O3 carrier, a noble metal Ru and an auxiliary metal Ni loaded on the carrier, the weight of the catalyst being 100%, the contents of the components being as follows: Ru 1.0%, Ni 20.0%, and the balance being the carrier; In the preparation method, the precursor salts of Ru and Ni are RuCl3·3H2O and NiCl2·6H2O respectively, and the rest are the same as in Example 1.

[0022] Example 4 A catalyst for preparing 1,1,2,3-tetrachloropropylene, the catalyst comprising a spherical Al2O3 carrier, a precious metal Pt and an auxiliary metal Mg supported on the carrier, wherein the weight of the catalyst is 100%, and the contents of the components are as follows: Pt 0.2%, Mg 10.0%, and the balance being the carrier; The preparation method of the catalyst is as follows: (1) 50.0 g of aluminum powder was added to 200.0 g of 8.5 wt% dilute hydrochloric acid solution, and the aluminum powder was dissolved at 80°C to form an aluminum sol having a Tyndall effect; (2) adding 0.6 g H2PtCl6·6H2O, 88.6 g MgCl2·6H2O and 5.0 g urea to the aluminum sol, and mixing and dissolving them thoroughly; (3) The mixture of step (2) was dripped into vacuum pump oil at 110° C. to form oil columns, and the formed pellets were separated, aged at 100° C. for 20 h, washed with pure water, dried at 150° C. for 5 h, and then calcined at 400° C. for 10 h in a mixed atmosphere of 50 mL / min and 20% H2 / N2 to obtain the catalyst.

[0023] 1. Catalytic performance test The catalyst was loaded into a quartz tube of a fixed bed reactor, 1,1,1,2,3-pentachloropropane was introduced to carry out dehydrochlorination reaction, and the product was analyzed by gas chromatography. The specific reaction conditions and results are shown in Table 1; Table 1 Specific reaction conditions and results 2. Stability performance test Under the reaction conditions of the catalyst in Example 1 above, the selectivity of the product was tested at different cumulative reaction times, as shown in Table 2; Table 2 Results of the catalysts described in Example 1 at different reaction times

Claims

1. A catalyst for preparing 1,1,2,3-tetrachloropropene, characterized in that: The catalyst is composed of a spherical Al2O3 carrier and a precious metal M1 and an auxiliary metal M2 loaded on the carrier, wherein M1 is any one of Pd, Pt or Ru, and M2 is any one of Mg, Ga, Ba, Fe, Co or Ni; the weight of the catalyst is 100%, and the content of each component is as follows: metal M1 0.2-3%, metal M2 10-30%, and the balance is the carrier.

2. The catalyst for preparing 1,1,2,3-tetrachloropropene according to claim 1, characterized in that: The M1 is any one of Pd and Ru.

3. The catalyst for preparing 1,1,2,3-tetrachloropropene according to claim 2, characterized in that: The M2 is any one of Fe, Co and Ni.

4. The method for preparing the catalyst for preparing 1,1,2,3-tetrachloropropene according to claim 1, characterized in that: The following steps are involved: (1) Add aluminum powder to a dilute hydrochloric acid solution or a crystalline aluminum chloride solution, dissolve the aluminum powder at 80-110°C to form an aluminum sol with a Tyndall effect; (2) adding soluble precursor salts of M1 and M2 and an organic amine to the aluminum sol; (3) dropping into an oil column at 70-110° C. to form the oil column, separating the formed small balls, aging, washing, drying, and then calcining in a mixed atmosphere of either hydrogen or hydrogen chloride and nitrogen to obtain the catalyst.

5. The method for preparing the catalyst for preparing 1,1,2,3-tetrachloropropene according to claim 4, characterized in that: In the aluminum sol of step (1), the aluminum content is 4-20 wt% and the Al / Cl mass ratio is 0.3-3; the concentration of the dilute hydrochloric acid solution is 5-20 wt%, and the concentration of the crystalline aluminum chloride solution is 10-20 wt%.

6. The method for preparing the catalyst for preparing 1,1,2,3-tetrachloropropene according to claim 5, characterized in that: The organic amine is any one of hexamethylenetetramine and urea, and the mass ratio of Al to the organic amine in the aluminum sol is 0.8-10.

7. The method for preparing the catalyst for preparing 1,1,2,3-tetrachloropropene according to claim 6, characterized in that: The aging condition is aging at 100-180° C. for 5-20 h.

8. The method for preparing the catalyst for preparing 1,1,2,3-tetrachloropropene according to claim 7, characterized in that: The volume fraction of hydrogen or hydrogen chloride in the mixed gas is 5-20%, and the flow rate of the mixed atmosphere is 50-500 mL / min.

9. The method for preparing the catalyst for preparing 1,1,2,3-tetrachloropropene according to claim 8, characterized in that: The drying is carried out at 50-150° C. for 5-20 hours; the roasting is carried out at 400-800° C. for 3-10 hours; and the oil in the oil column is one of vacuum pump oil and edible oil.

10. A method for catalyzing 1,1,1,2,3-pentachloropropane to synthesize 1,1,2,3-tetrachloropropene, characterized in that: The catalyst is loaded into a quartz tube of a fixed bed reactor, and 1,1,1,2,3-pentachloropropane is introduced for dehydrochlorination reaction. The reaction temperature is 200-250°C, the reaction pressure is 0.1-1 Mpa, and the mass space velocity is 0.1-0.5 h -1 , collecting the reaction products; wherein the catalyst is the catalyst according to claim 1.

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