CATALYST FOR FIXED BED ANILINE RECTIFICATION RESIDUE RECYCLING AND PREPARATION METHOD

Abstract

The present invention relates to a catalyst for fixed bed aniline rectification residue recycling and preparation method thereof. Based on the total weight of the catalyst, the catalyst comprises the following components in percentage by weight: 5-40% of an active component, 2-30% of a first cocatalyst component, 10-30% of a second cocatalyst component and the balance of carrier, wherein the active component is NiO; the first cocatalyst component is one or more of Fe, Mo, Cr or Co oxide; and the second cocatalyst component is one or more of La, Zr, Y or Ce oxide. The catalyst is prepared through co-precipitation. The catalyst shows high activity and stability in the waste liquid treatment process, and can still maintain high rectification residue cracking rate after reaction of 200 hours.

Claims

1. A process of recycling aniline rectification residue, comprising subjecting the aniline rectification residue to fixed bed hydrogenation with a catalyst, wherein said catalyst comprises the components described below based on the total weight of the catalyst: 5-40 wt % of NiO as an active component, 2-30 wt % of one or more selected from oxides of Fe, oxides of Mo, oxides of Cr and oxides of Co as a first cocatalyst component, 10-30 wt % of one or more selected from oxides of La, oxides of Zr, oxides of Y and oxides of Ce as a second cocatalyst component, the remaining portion being the support.

2. The process of claim 1, wherein said catalyst comprises the components described below based on the total weight of the catalyst: 15-30 wt % of NiO as the active component, 5-25 wt % of one or more selected from oxides of Fe, oxides of Mo, oxides of Cr and oxides of Co as the first cocatalyst component, 15-25 wt % of one or more selected from oxides of La, oxides of Zr, oxides of Y and oxides of Ce as the second cocatalyst component, the remaining portion being the support.

3. The process of claim 1, wherein the support is SiO.sub.2.

4. The process of claim 1, wherein the aniline rectification residue is treated by gas phase hydrogenation to obtain cyclohexyl amine and dicyclohexyl amine, using monofunctional saturated alcohol as the diluent, under the catalysis of the catalyst, at a certain temperature and pressure.

5. The process of claim 4, wherein the monofunctional saturated alcohol is ethanol or methanol.

6. The process of claim 4, wherein the monofunctional saturated alcohol/aniline rectification residue in mass ratio of 0.1-0.7:1 is introduced to a fixed bed reactor, wherein the liquid phase volume space velocity is 0.6-1.5 h.sup.1, the reaction pressure is 1-4 MPa, the reaction temperature is between 250-320 C., and the volume ratio of the hydrogen amount and the amount of aniline rectification residue is 500-3000:1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is the gas chromatogram of the product of Example 1 of the present invention.

THE MODE OF CARRYING OUT THE INVENTION

[0029] The embodiments of the present invention are further described with reference to the Examples. The present invention should not be interpreted to be limited to these examples, rather comprise all variations and modifications within the scope of the claims.

[0030] The fixed bed reactor used in the Examples have a size of length 100 cm and inner diameter 25 mm. The reaction product is analyzed by Shimadzu GC-2014 gas chromatograph (hydrogen flame ionization (FID) detector) using internal standard method. The detection conditions are as follows: analytical column SE-30, capillary column (0.30 mm30 m), the gasification chamber 270 C., the detector 270 C. The column temperature is 70 C. and maintained for 1 min, and then rise to 240 C. at the rate of 40 C./ min and maintained for 5 min.

[0031] The aniline rectification residue used in the Examples is from the aniline rectification units of Ningbo Wanhua Polyurethane Co., Ltd.

Example 1

[0032] 16 g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O, 20 g of ferric nitrate Fe(NO.sub.3).sub.3.Math.9H.sub.2O and 11 g of lanthanum nitrate La(NO.sub.3).sub.3 .Math.6H.sub.2O are weighed respectively, and dissolved in 300 ml of distilled water, referred to as solution A.

[0033] 15 mass % of aqueous ammonia solution (200 ml) is formulated, referred to as solution B.

[0034] 17 g of sodium silicate (Na.sub.2SiO.sub.3) is weighed and dissolved in 150 ml water, referred to as solution C.

[0035] Firstly, 100 ml water in a sedimentation tank is heated to 50 C., and the solution A, B and C are added dropwise to the sedimentation tank. In the preparation process, pH and the precipitation temperature are maintained at 7.5 and 60 C. respectively. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the precipitate is calcined under air atmosphere at 400 C. for 4 h, and then grinded, extrusion molded, pulverized and sieved to 10-20 mesh. Finally, 20% NiO-20% Fe.sub.2O.sub.3/40% SiO.sub.2-20% La.sub.2O.sub.3 is prepared.

[0036] 10 ml of the above-said catalyst is packed in a fixed bed reactor, and reduced at 400 C. After the reduction, the temperature is lowered to the reaction temperature of 280 C., the system pressure is raised to 1.5 MPa, and the feeding is initiated, wherein the mass ratio of ethanol and aniline rectification residue is 0.2:1. Liquid phase space velocity is 0.7 h.sup.1, and H.sub.2 flow rate is 200 ml/min. After 10 h reaction, sampling is conducted for analysis, and cyclohexyl amine and dicyclohexyl amine yields are 33.6% and 24%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 31.2% and 24.6% respectively.

Example 2

[0037] 24g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O, 20 g of ferric nitrate Fe(NO.sub.3).sub.3.Math.9H.sub.2O and 7 g of yttrium nitrate Y(NO.sub.3).sub.3.Math.6H.sub.2O are weighed respectively, and dissolved in 300 ml of distilled water, referred to as solution A. 0.7 mol/L of Na.sub.2CO.sub.3 solution is formulated, 17 g of sodium silicate (Na.sub.2SiO.sub.3) is weighed and dissolved in 300 ml Na.sub.2CO.sub.3 solution, referred to as solution B.

[0038] Firstly, water in the sedimentation tank is heated to 70 C., and the solution A and B are added dropwise to a sedimentation tank in a parallel flow. In the preparation process, pH and the precipitation temperature are maintained at 8 and 70 C. respectively. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the precipitate is calcined under air atmosphere at 500 C. for 4 h, and then grinded, compression molded, pulverized and sieved to 10-20 mesh. Finally, 30% NiO-20% Fe.sub.2O.sub.3/40% SiO.sub.2-10% Y.sub.2O.sub.3 is prepared.

[0039] 10ml of the above-said catalyst is packed in a fixed bed reactor, and reduced at 450 C. After the reduction, the temperature is lowered to the reaction temperature of 300 C., the system pressure is raised to 2 MPa, and the feeding is initiated, wherein the mass ratio of ethanol and aniline rectification residue is 0.2. Liquid phase space velocity is 0.7h.sup.1, and H.sub.2 flow rate is 250ml/min. After 10 h reaction, sampling is conducted for analysis, and cyclohexyl amine and dicyclohexyl amine yields are 36.8% and 40%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 35.8% and 38.7% respectively.

Example 3

[0040] 20 g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O, 8 g of cobalt nitrate Co(NO.sub.3).sub.2.Math.6H.sub.2O and 15 g of cerium nitrate Ce(NO.sub.3).sub.3.Math.6H.sub.2O are weighed respectively, and dissolved in 200 ml of distilled water, referred to as solution A.

[0041] 1 mol/L of NaOH solution is formulated, 17 g of sodium silicate (Na.sub.2SiO.sub.3) is dissolved in 200 ml NaOH solution, referred to as solution B.

[0042] Firstly, the solution B is poured into a sedimentation tank and heated to 70 C., and the solution A is added dropwise to the sedimentation tank slowly. In the meantime, the precipitation temperature is maintained at 70 C. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the precipitate is calcined under air atmosphere at 550 C. for 4 h, and then grinded, compression molded, pulverized and sieved to 10-20 mesh. Finally, 24% NiO-10% Co.sub.3O.sub.4/39% SiO.sub.2-27% CeO.sub.2 is prepared.

[0043] The evaluation of the catalyst is the same as that of Example 2. Cyclohexyl amine and dicyclohexyl amine yields are 31.2% and 33.2%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 28% and 32.5% respectively.

Example 4

[0044] 20 g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O, 17 g of sodium silicate Na.sub.2SiO.sub.3, 8 g of cobalt nitrate Co(NO.sub.3).sub.2.Math.6H.sub.2O and 15 g of cerium nitrate Ce(NO.sub.3).sub.3.Math.6H.sub.2O are weighed respectively, and dissolved in 200 ml of distilled water, referred to as solution A.

[0045] 15 mass % of aqueous ammonia solution (200 ml) is formulated, referred to as solution B.

[0046] Firstly, the solution A is poured into a sedimentation tank and heated to 70 C., and the solution B is added dropwise to the sedimentation tank slowly. In the meantime, the precipitation temperature is maintained at 70 C. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the precipitate is calcined under air atmosphere at 600 C. for 4 h, and then grinded, compression molded, pulverized and sieved to 10-20 mesh. Finally, 20% NiO-10% Co.sub.3O.sub.4/40% SiO.sub.2-30% CeO.sub.2 is prepared.

[0047] The evaluation of the catalyst is the same as that of Example 2. Cyclohexyl amine and dicyclohexyl amine yields are 30.1% and 23.7%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 28.8% and 22.3% respectively.

Example 5

[0048] 18 g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O, 18 g of cobalt nitrate Co(NO.sub.3).sub.2.Math.6H.sub.2O and 10 g of yttrium nitrate Y(NO.sub.3).sub.3.Math.6H.sub.2O are weighed respectively, and dissolved in 200 ml of distilled water, referred to as solution A.

[0049] 200 ml of 1 mol/L of Na.sub.2CO.sub.3 solution is formulated, and therein 14.6 g of sodium silicate (Na.sub.2SiO.sub.3) is dissolved, referred to as solution B.

[0050] Firstly, water in the sedimentation tank is heated to 70 C., and the solution A and B are added dropwise to a sedimentation tank in a parallel flow. In the preparation process, pH and the precipitation temperature are maintained at 8 and 70 C. , respectively. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the precipitate is calcined under air atmosphere at 500 C. for 4 h, and then grinded, compression molded, pulverized and sieved to 10-20 mesh. Finally, 24% NiO-25% Co.sub.3O.sub.4/36% SiO.sub.2-15% Y.sub.2O.sub.3 is prepared.

[0051] 10 ml of the above-said catalyst is packed in a fixed bed reactor, and reduced at 500 C. After the reduction, the temperature is lowered to the reaction temperature of 280 C., the system pressure is raised to 2.5 MPa, and the feeding is initiated, wherein the mass ratio of ethanol and aniline rectification residue is 0.3. Liquid phase space velocity is 0.7 h.sup.1, and H.sub.2 flow rate is 250 ml/min. After 10 h reaction, sampling is conducted for analysis, and cyclohexyl amine and dicyclohexyl amine yields are 37.2% and 41.5%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 36.8% and 40.1% respectively.

Example 6

[0052] 18 g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O, 18 g of cobalt nitrate Co(NO.sub.3).sub.2.Math.6H.sub.2O, 3 g of zirconium nitrate Zr(NO.sub.3).sub.4.Math.5H.sub.2O, and 5 g of cerium nitrate Ce(NO.sub.3).sub.3.Math.6H.sub.2O are weighed respectively, and dissolved in 200 ml of distilled water, referred to as solution A.

[0053] 200 ml of 1 mol/L of Na.sub.2CO.sub.3 solution is formulated, and therein 14 g of sodium silicate (Na.sub.2SiO.sub.3) is dissolved, referred to as solution B.

[0054] Firstly, water in the sedimentation tank is heated to 70 C., and the solution A and B are added dropwise to a sedimentation tank in a parallel flow. In the preparation process, pH and the precipitation temperature are maintained at 8 and 70 C. , respectively. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the precipitate is calcined under air atmosphere at 500 C. for 4 h, and then grinded, compression molded, pulverized and sieved to 10-20 mesh. Finally, 24% NiO-25% Co.sub.3O.sub.4/36% SiO.sub.2-5% ZrO.sub.2-10% CeO.sub.2 is prepared.

[0055] 10ml of the above-said catalyst is packed in a fixed bed reactor, and reduced at 500 C. After the reduction, the temperature is lowered to the reaction temperature of 290 C., the system pressure is raised to 2.5 MPa, and the feeding is initiated, wherein the mass ratio of ethanol and aniline rectification residue is 0.4. Liquid phase space velocity is 0.7h.sup.1, and H.sub.2 flow rate is 250 ml/min. After 10 h reaction, sampling is conducted for analysis, and cyclohexyl amine and dicyclohexyl amine yields are 32.5% and 33.7%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 31.7% and 32.1% respectively.

Example 7

[0056] 16 g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O, 11 g of cobalt nitrate Co(NO.sub.3).sub.2.Math.6H.sub.2O, 10 g of ferric nitrate Fe(NO.sub.3).sub.3.Math.9H.sub.2O and 10 g of yttrium nitrate Y(NO.sub.3).sub.3.Math.6H.sub.2O are weighed respectively, and dissolved in 200 ml of distilled water, referred to as solution A.

[0057] 250 ml of 1 mol/L of Na.sub.2CO.sub.3 solution is formulated, and therein 16 g of sodium silicate (Na.sub.2SiO.sub.3) is dissolved, referred to as solution B.

[0058] Firstly, water in the sedimentation tank is heated to 70 C., and the solution A and B are added dropwise to a sedimentation tank in a parallel flow. In the preparation process, pH and the precipitation temperature are maintained at 8 and 70 C. , respectively. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the precipitate is calcined under air atmosphere at 500 C. for 5 h, and then grinded, compression molded, pulverized and sieved to 10-20 mesh. Finally, 20% NiO-15% Co.sub.3O.sub.4-10% Fe.sub.2O.sub.3/40% SiO.sub.2-15% Y.sub.2O.sub.3is prepared.

[0059] 10 ml of the above-said catalyst is packed in a fixed bed reactor, and reduced at 500 C. After the reduction, the temperature is lowered to the reaction temperature of 300 C., the system pressure is raised to 2.5 MPa, and the feeding is initiated, wherein the mass ratio of ethanol and aniline rectification residue is 0.4. Liquid phase space velocity is 0.7h.sup.1, and H.sub.2 flow rate is 250 ml/min. After 10 h reaction, sampling is conducted for analysis, and cyclohexyl amine and dicyclohexyl amine yields are 36.9% and 40.2%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 35.8% and 39.5% respectively.

Example 8

[0060] 24g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O and 14 g of yttrium nitrate Y(NO.sub.3).sub.3.Math.6H.sub.2O are weighed respectively, and dissolved in 300 ml of distilled water, referred to as solution A. 300 ml of 0.7 mol/L of Na.sub.2CO.sub.3 solution is formulated, and 17 g of sodium silicate (Na.sub.2SiO.sub.3) is weighed and dissolved in the Na.sub.2CO.sub.3 solution, referred to as solution B.

[0061] Firstly, water in the sedimentation tank is heated to 70 C., and the solution A and B are added dropwise to a sedimentation tank in a parallel flow. In the preparation process, pH and the precipitation temperature are maintained at 8 and 70 C. , respectively. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the resulting catalyst is immersed in ammonium molybdate ((NH.sub.4).sub.6Mo.sub.7O.sub.24 .Math.4H.sub.2O) solution for 5 h, calcined under air atmosphere at 500 C. for 4 h, and then grinded, compression molded, pulverized and sieved to 10-20 mesh. Finally, 30% NiO-10% MoO.sub.3/40% SiO.sub.2-20% Y.sub.2O.sub.3 is prepared.

[0062] 10 ml of the above-said catalyst is packed in a fixed bed reactor, and reduced at 450 C. After the reduction, the temperature is lowered to the reaction temperature of 300 C., the system pressure is raised to 2 MPa, and the feeding is initiated, wherein the mass ratio of ethanol and aniline rectification residue is 0.2. Liquid phase space velocity is 0.7h.sup.1, and H.sub.2 flow rate is 250 ml/min. After 10 h reaction, sampling is conducted for analysis, and cyclohexyl amine and dicyclohexyl amine yields are 38.8% and 36.7%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 36.2% and 34.5% respectively.

Example 9

[0063] 20g of nickel nitrate Ni(NO.sub.3).sub.2.Math.6H.sub.2O, 17 g of sodium silicate Na.sub.2SiO.sub.3, 8 g of chromium nitrate Cr(NO.sub.3).sub.3.Math.9H.sub.2O and 15 g of cerium nitrate Ce(NO.sub.3).sub.3.Math.6H.sub.2O are weighed respectively, and dissolved in 200 ml of distilled water, referred to as solution A.

[0064] 20mass % of aqueous ammonia solution (150ml) is formulated, referred to as solution B.

[0065] Firstly, the solution A is poured into a sedimentation tank and heated to 70 C., and the solution B is added dropwise to the sedimentation tank slowly. In the meantime, the precipitation temperature is maintained at 70 C. After the end of precipitation, the stirring speed and precipitation temperature are kept unchanged, and the resulting precipitate is aged for 4 h, filtered and washed to neutral. Thereafter, the precipitate is placed in an oven of 110 C. and dried for 12 h. After the end of drying, the precipitate is calcined under air atmosphere at 600 C. for 3 h, and then grinded, compression molded, pulverized and sieved to 10-20 mesh. Finally, 24.5% NiO-7.2% Cr.sub.2O.sub.3/39.9% SiO.sub.2-28.4% CeO.sub.2 is prepared.

[0066] The evaluation of the catalyst is the same as that of Example 2. Cyclohexyl amine and dicyclohexyl amine yields are 28.3% and 20.7%, respectively. After 200 h reaction, cyclohexyl amine and dicyclohexyl amine yields are maintained at 25.8% and 18.4% respectively.