CO shift catalyst carrier, catalyst based on the catalyst carrier and preparation process thereof

Abstract

The present invention provides a catalyst carrier with shift and adsorption purification performance, comprising modified bauxite in the raw material components which fluxing and pore forming effects. Most iron oxide contained in the bauxite is removed after modification, so that there are a large amount of highly active aluminosilicate compounds in the modified bauxite. When preparing the catalyst, the aluminosilicate compound serves as a low melting point flux and can significantly increase the migration rate of magnesium and aluminum ions during the calcinating process and promote the generation of MgAl.sub.2O.sub.4 at low temperatures, thereby the catalyst carrier of the present invention has strong anti-hydration capacity and mechanical strength. In addition, when the modified bauxite is used as macroporous hard template for the preparation of the catalyst, macro pores can be formed in the structure of the catalyst carrier after calcinating treatment, so that the catalyst carrier of the present invention has strong adsorption purification ability on macromolecular particles including oil pollution and dust.

Claims

1. A catalyst carrier with shift and adsorption purification performance, comprising the following components: modified bauxite, 8-15 parts by weight; alumina or pseudo-boehmite, 40-53 parts by weight; and magnesium oxide or magnesium hydroxide, 25-32 parts by weight; wherein, the modified bauxite is prepared by steps of: subjecting a natural bauxite to an acid treatment to obtain a treated bauxite, then washing the treated bauxite with distilled water until a waste washing solution is neutral, followed by filtering and drying to obtain the modified bauxite, wherein the catalyst carrier comprises macropore in its structure, the macropore having a diameter of 100-300 nm and accounting for 18.2%-28.3% of the catalyst carrier by volume, and wherein the acid treatment is carried out at a temperature of 30-70 C. for a period of 2-8 hours.

2. The catalyst carrier of claim 1, wherein, the acid is selected from the group consisting of nitric acid, phosphoric acid, oxalic acid, boric acid or mixtures thereof; and the acid has a concentration of 1-3 mol/L.

3. The catalyst carrier of claim 1, wherein, the drying is carried out at a temperature of 120-150 C. for a period of 4-6 hours.

4. The catalyst carrier of claim 1, wherein, the modified bauxite has a particle size of 100-150 mesh, a specific surface area of 120-180 m.sup.2/g, and a pore volume of 0.15-0.40 ml/g.

5. A catalyst based on the catalyst carrier of claim 1, wherein, the catalyst carrier is loaded with an active ingredient comprising CoO and/or NiO in 2-5 parts by weight, and MoO.sub.3 and/or WO.sub.3 in 6-10 parts by weight.

6. A process for preparing the catalyst of claim 5, comprising the steps of: (1) Weighing the modified bauxite, alumina or pseudo-boehmite and magnesium oxide or magnesium hydroxide according to the above-mentioned parts by weight, then fully kneading them with cobalt source and/or nickel source, molybdenum source and/or tungsten source to obtain a mixture; (2) Extruding the mixture to obtain an extruded product; (3) Drying and calcining the extruded product to obtain a catalyst that has shift and adsorption purification performance.

7. The process of claim 6, wherein, the cobalt source is cobalt oxalate, the nickel source is nickel oxalate; the molybdenum source is molybdenum trioxide and/or molybdenum concentrate, and the tungsten source is tungsten trioxide.

8. The process of claim 7, wherein, in step (3), the drying is carried out at a temperature of 110-140 C. for a period of 4-8 hours; and the calcining is carried out at a temperature of 580-680 C. for a period of 4-8 hours.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order to make the content of the present invention are more likely to be clearly understood, the content of the present invention will now be described in detail with reference to certain Examples and FIGURE, and wherein,

(2) FIG. 1 is an XRD pattern of different carriers after the anti-hydration performance test.

DETAILED EMBODIMENTS OF THIS INVENTION

(3) 1 part by weight represents, for example, 1 g in the following examples.

Example 1

(4) The example 1 provides a catalyst carrier with shift and adsorption purification performance, the catalyst carrier comprises macropore in its structure, and the macropore has a diameter of 100 nm and accounts for 10% of the catalyst carrier by volume.

(5) The catalyst carrier with shift and adsorption purification performance comprises the following components:

(6) modified bauxite, 8 parts by weight;

(7) alumina, 53 parts by weight;

(8) magnesium oxide, 32 parts by weight;

(9) The modified bauxite is prepared by steps of:

(10) subjecting a natural bauxite to an acid treatment with 1 mol/L of nitric acid at a temperature of 30 C. for a period of 8 hours to obtain a treated bauxite, then washing the treated bauxite with distilled water until a waste washing solution is neutral, followed by filtering and drying at a temperature of 120 C. for a period of 6 hours to obtain the modified bauxite having a particle size of 150 mesh, a specific surface area of 150 m.sup.2/g, and a pore volume of 0.25 ml/g.

(11) A catalyst based on the catalyst carrier with shift and adsorption purification performance is further provided. The catalyst carrier is loaded with an active ingredient comprising

(12) NiO in 3.5 parts by weight, and

(13) MoO.sub.3 in 8.5 parts by weight.

(14) The catalyst is prepared by steps of:

(15) (1) Weighing the modified bauxite, alumina and magnesium oxide according to the above-mentioned parts by weight, fully kneading with nickel oxalate and molybdenum trioxide to obtain a mixture;

(16) (2) Extruding the mixture to obtain extruded products;

(17) (3) Drying and calcining the extruded product to obtain the catalyst that has shift and adsorption purification performance;

(18) wherein, the drying is carried out at a temperature of 140 C. for a period of 4 hours; the calcining is carried out at a temperature of 680 C. for a period of 4 hours.

Example 2

(19) The example 2 provides a catalyst carrier with shift and adsorption purification performance, the catalyst carrier comprises macropore in its structure, and the macropore has a diameter of 300 nm and accounts for 30% of the catalyst carrier by volume.

(20) The catalyst carrier with shift and adsorption purification performance comprises the following components:

(21) Modified bauxite, 10 parts by weight;

(22) Alumina, 40 parts by weight;

(23) Magnesium oxide, 28 parts by weight;

(24) The modified bauxite is prepared by steps of:

(25) subjecting a natural bauxite to an acid treatment with 3 mol/L of phosphoric acid at a temperature of 70 C. for a period of 2 hours to obtain a treated bauxite, then washing the treated bauxite with distilled water until a waste washing solution is neutral, followed by filtering and drying at a temperature of 150 C. for a period of 4 hours to obtain the modified bauxite having a particle size of 100 mesh, a specific surface area of 120 m.sup.2/g, and a pore volume of 0.40 ml/g.

(26) A catalyst based on the catalyst carrier with shift and adsorption purification performance is further provided. The catalyst carrier is loaded with an active ingredient comprising

(27) CoO in 2 parts by weight,

(28) MoO.sub.3 in 7 parts by weight, and

(29) WO.sub.3 in 3 parts by weight.

(30) The catalyst is prepared by steps of:

(31) (1) Weighing the modified bauxite, alumina and magnesium oxide according to the above-mentioned parts by weight, fully kneading with cobalt oxalate, molybdenum trioxide and tungsten trioxide to obtain a mixture;

(32) (2) Extruding the mixture is to obtain extruded products;

(33) (3) Drying and calcining the extruded product to obtain the catalyst that has shift and adsorption purification performance;

(34) wherein, the drying is carried out at a temperature of 120 C. for a period of 6 hours; the calcining is carried out at a temperature of 600 C. for a period of 5 hours.

Example 3

(35) The example 3 provides a catalyst carrier with shift and adsorption purification performance, the catalyst carrier comprises macropore in its structure, and the macropore has a diameter of 200 nm and accounts for 20% of the catalyst carrier by volume.

(36) The catalyst carrier with shift and adsorption purification performance comprises the following components:

(37) modified bauxite, 15 parts by weight;

(38) pseudo-boehmite, 50 parts by weight;

(39) magnesium hydroxide, 25 parts by weight;

(40) The modified bauxite is prepared by steps of:

(41) subjecting a natural bauxite to an acid treatment with 2 mol/L of oxalic acid at a temperature of 40 C. for a period of 6 hours to obtain a treated bauxite, then washing the treated bauxite with distilled water until a waste washing solution is neutral, followed by filtering and drying at a temperature of 130 C. for a period of 5 hours to obtain the modified bauxite having a particle size of 120 mesh, a specific surface area of 180 m.sup.2/g, and a pore volume of 0.15 ml/g.

(42) A catalyst based on the catalyst carrier with shift and adsorption purification performance is further provided. The catalyst carrier is loaded with an active ingredient comprising

(43) CoO in 3 parts by weight,

(44) NiO in 2 parts by weight, and

(45) MoO.sub.3 in 6 parts by weight.

(46) The catalyst is prepared by steps of:

(47) (1) Weighing the modified bauxite, pseudo-boehmite and magnesium hydroxide according to the above-mentioned parts by weight, fully kneading with cobalt oxalate, nickel oxalate and molybdenum trioxide to obtain a mixture;

(48) (2) Extruding the mixture to obtain extruded products;

(49) (3) Drying and calcining the extruded product to obtain the catalyst that has shift and adsorption purification performance;

(50) wherein, the drying is carried out at a temperature of 110 for a period of 8 hours; the calcining is carried out at a temperature of 650 C. for a period of 4 hours.

Example 4

(51) The example 4 provides a catalyst carrier with shift and adsorption purification performance, the catalyst carrier comprises macropore in its structure, and the macropore has a diameter of 250 nm and accounts for 25% of the catalyst carrier by volume.

(52) The catalyst carrier with shift and adsorption purification performance comprising the following components:

(53) modified bauxite, 5 parts by weight;

(54) pseudo-boehmite, 60 parts by weight;

(55) magnesium oxide, 20 parts by weight;

(56) The modified bauxite is prepared by steps of:

(57) subjecting a natural bauxite to an acid treatment with 3 mol/L of boric acid at 60 C. for a period of 6 hours to obtain a treated bauxite, then washing the treated bauxite with distilled water until a waste washing solution is neutral, followed by filtering and drying at a temperature of 130 C. for a period of 5 hours to obtain the modified bauxite having a particle size of 140 mesh, a specific surface area of 161 m.sup.2/g, and a pore volume of 0.22 ml/g.

(58) A catalyst based on the catalyst carrier with shift and adsorption purification performance is further provided. The catalyst carrier is loaded with an active ingredient comprising

(59) CoO in 5 parts by weight,

(60) MoO.sub.3 in 7 parts by weight, and

(61) WO.sub.3 in 3 parts by weight.

(62) The catalyst is prepared by steps of:

(63) (1) Weighing the modified bauxite, pseudo-boehmite and magnesium oxide according to the above-mentioned parts by weight, fully kneading with cobalt oxalate, molybdenum concentrate and tungsten trioxide to obtain a mixture;

(64) (2) Extruding the mixture to obtain extruded products;

(65) (3) Drying and calcining the extruded product to obtain the catalyst that has shift and adsorption purification performance;

(66) wherein, the drying is carried out at a temperature of 120 C. for a period of 6 hours; the calcining is carried out at a temperature of 580 C. for a period of 6 hours.

Comparative Example 1

(67) The comparative example 1 provides a catalyst carrier, comprising the following components:

(68) natural bauxite, 10 parts by weight;

(69) alumina, 40 parts by weight;

(70) magnesium oxide, 28 parts by weight;

(71) A catalyst based on the catalyst carrier with shift and adsorption purification performance is further provided. The catalyst carrier is loaded with an active ingredient comprising

(72) CoO in 2 parts by weight,

(73) MoO.sub.3 in 7 parts by weight, and

(74) WO.sub.3 in 3 parts by weight.

(75) The catalyst is prepared by steps of:

(76) (1) Weighing the natural bauxite, alumina or magnesium oxide according to the above-mentioned parts by weight, fully kneading with cobalt source cobalt oxalate, molybdenum trioxide and tungsten trioxide to obtain a mixture;

(77) (2) Extruding the mixture to obtain an extruded product;

(78) (3) Drying and calcining the extruded product to obtain the catalyst; wherein, the drying is carried out at a temperature of 120 C. for a period of 6 hours; the calcining is carried out at a temperature of 600 C. for a period of 5 hours.

Comparative Example 2

(79) The comparative example 2 provides a catalyst carrier, comprising the following components:

(80) hydrothermally modified bauxite, 10 parts by weight;

(81) alumina, 40 parts by weight;

(82) magnesium oxide, 28 parts by weight; The hydrothermally modified bauxite is prepared by steps of:

(83) Placing natural bauxite in a high-pressure reactor for hydrothermal treatment at a temperature of 130for a period of 48 hours, filtering, drying at a temperature of 150 for a period of 4 hours, calcinating at a temperature of 550 for a period of 4 hours, and cooling to obtain the hydrothermally modified bauxite.

(84) A catalyst based on the catalyst carrier is further provided. The catalyst carrier is loaded with an active ingredient comprising

(85) CoO in 2 parts by weight,

(86) MoO.sub.3 in 7 parts by weight, and

(87) WO.sub.3 in 3 parts by weight.

(88) The catalyst is prepared by steps of:

(89) (1) Weighing the hydrothermally modified bauxite, alumina and magnesium oxide according to the above-mentioned parts by weight, fully kneading with cobalt oxalate, molybdenum trioxide and tungsten trioxide to obtain a mixture;

(90) (2) Extruding the mixture to obtain an extruded product;

(91) (3) Drying and calcining the extruded product to obtain the catalyst; wherein, the drying is carried out at a temperature of 120 C. for a period of 6 hours; the calcining is carried out at a temperature of 600 C. for a period of 5 hours.

Experimental Example

(92) In order to prove the technical effects of the catalyst carrier with shift and adsorption purification performance of the present invention, experimental examples of the present invention were provided to test the catalytic properties of the carrier and the catalyst.

(93) Carriers in Examples 1-4 and Comparative Examples 1-2 were sequentially numbered as A-F and subjected to the following test.

(94) Testing Experiments of Carrier Pore Structure

(95) The carrier pore structure of the experimental example was measured on the AutoPoreIV 9500 Automatic Mercury Porosimeter from Micrometrics Company in the United States. The shift relationship between the applied pressure and the volume of intruded mercury was recorded during a pressing process, and the pore structure was analyzed based on Washburn equation:

(96) $P=\frac{2\cos }{r}$

(97) Wherein, P was the measured pore pressure; r was the radius; was wetting angle; was the surface tension of mercury. The mercury wetting angle is 130, the surface tension is 0.485 N/m, and the initial test pressure is 3.7310.sup.3 MPa and the maximum test pressure is 207 MPa.

(98) The test results of pore structure of the carrier were shown in Table 1.

(99) TABLE-US-00001 TABLE 1 the test results of pore structure of the carrier The volume fraction of the macropore having a diameter of Samples 100-300 nm/% A 18.2 B 21.6 C 28.3 D 9.6 E 9.3 F 12.5

(100) As can be seen from the data in Table 1, the structure of the catalyst carrier (samples A-D) obtained by the process of the present invention comprised macropore having a diameter of 100-300 nm, and the macropore accounted for 10-30% of the catalyst carrier by volume, which would help to improve the adsorption purification ability on macromolecular particles including oil pollution and dust. In contrast, the carrier (sample E) which was prepared by adding acid treated natural bauxite and the carrier (sample F) which was prepared by using bauxite obtained with a hydrothermal process in the comparative examples, the macropore in its structure having a pore size which was greater than 100 nm accounted for only 9.3%, 12.5% of the catalyst carrier by volume, respectively, and thus had poor adsorption purification ability on macromolecular particles including oil pollution and dust.

(101) The Test Experiment of Carrier Strength

(102) Experimental procedure was described as follows:

(103) According to quartering, 40 g carrier samples A-F were respectively tested on in ZQJ-II intelligent particle strength tester (being directed by national chemical catalyst test center) to obtain line contact crush strength, respectively. An average value represented catalyst strength level.

(104) The test results of Carrier strength were shown in Table 2.

(105) TABLE-US-00002 TABLE 2 the test results of Carrier strength Samples Intensity/(N/cm) A 196 B 185 C 176 D 223 E 88 F 106

(106) As can be seen from data in Table 2, the carrier (samples A-D) obtained by the preparation process of the present invention has a high strength of 176-223N/cm, and thus could be applied to a hydrogen producing shift reaction of feed gas having high CO concentration, high steam gas ratio and high pressure. In contrast, the carrier (sample E) which was prepared by adding acid treated natural bauxite and the carrier (sample F) which was prepared by using bauxite obtained with a hydrothermal process in the Comparative examples had a low strength of only 88 N/cm and 106 N/cm respectively, a poor anti-hydration performance and could be easily inactivated or pulverized, thus they could not be applied to a hydrogen producing shift reaction of feed gas having high CO concentration, high steam gas ratio and high pressure.

(107) The Test of Anti-Hydration Performance of Carrier

(108) The samples of carrier A-E were ground to 80-160 mesh powder, respectively. 10 g powder of each carrier sample and 50 mL of distilled water were put into a 100 mL-hydrothermal reaction kettle loaded with Teflon, sealed, hydrothermally treated at 200 C. for 4 h. Then the hydrothermally treated samples were dried at 110 C. for 6 h. And the change of crystal phase thereof was detected by using X-ray diffractometer.

(109) The XRD patterns of the above various carriers after the anti-hydration test were shown in FIG. 1. As can be seen, the carriers (samples A-D) of the present invention still maintained a good MgAl.sub.2O.sub.4 structure after the hydrothermal treatment, without other new material phase forming, thus showing strong anti-hydration properties. While diffraction peaks of AlOOH and ((Mg.sub.4Al.sub.2) (OH).sub.12CO3 (H.sub.2O).sub.3).sub.0.5 hydration products as well as MgAl.sub.2O.sub.4 spinel phase appeared after hydrothermal treatment for the carrier (Sample E) obtained in the Comparative examples, resulting in weak anti-hydration properties.

(110) Furthermore, carriers in Examples 1-4 and Comparative Examples 1-2 were sequentially numbered as A1-F1 and were subjected to the following tests.

(111) CO Shift Reaction Activity Evaluation Test of the Catalyst

(112) The experimental procedure is as follows:

(113) (1) Catalyst Sulfidation

(114) The sulfidation is divided into three stages: first stage, sulfidation at 250 for 360 min; second stage, the temperature was raised to 350 and continued sulfuring for 240 min; third stage, sulfidation at 420 for 180 min;

(115) (2) Activity Tests of the Catalyst:

(116) Evaluation Conditions:

(117) Feed gas composition: 46% of CO, 6% of CO.sub.2, the balance being H.sub.2;

(118) Catalyst loading volume was 30 ml, pressure was 5 MPa, space velocity was 3000 h.sup.1, the volume ratio of water vapor to dry feed gas, ie., steam-gas ratio, was 1.2.

(119) After sulfidation, the activity thereof was tested according to the above evaluation conditions, wherein the reaction temperature was in the range of 250-350 C., the heating rate was 3 C./min, the temperature interval was 50 C., the holding time of each test temperature point was 4 h. CO content before and after reaction was tested using GC-2014 gas chromatograph analyzer, and samples were automatically collected by six-way valve.

(120) The shift activity of the catalyst was represented by CO conversion rate, which was calculated as follows:
CO conversion rate (%)=100%(1Vo/Vi)/(1+Vo)

(121) Wherein, Vi was the volume fraction of CO in the feed gas, Vo was the volume fraction of CO in the conversion of gas.

(122) When the shift reaction temperature was 250 C., 300 C., 350 C., the CO conversion rate of the catalyst was calculated and the results were shown in Table 3.

(123) TABLE-US-00003 TABLE 3 CO conversion rate of catalyst under different shift reaction temperatures Samples 250 C. 300 C. 350 C. A1 33.5% 49.5% 56.9% B1 36.4% 53.3% 60.3% C1 41.3% 60.4% 65.3% D1 35.1% 58.6% 62.4% E1 68.7% 81.3% 85.2% F1 72.0% 83.4% 87.7%

(124) As can be seen from the data in Table 3, the catalyst of the present invention (Samples A1-D1) had moderate CO shift reaction catalytic activity. When they were applied to hydrogen producing shift reaction of feed gas having high CO concentration, high steam gas ratio and high pressure, CO in the feed gas can be converted in a controllable step manner and the temperature of catalyst bed can be controlled within a reasonable range. In contrast, the catalytic activity of the comparative catalysts (sample E1 and the sample F1) was too high and catalyst inactivation easily occur due to high temperature sintering, and even lead to runaway phenomenon of the catalyst bed, and thus they cannot be applied to a hydrogen producing shift reaction of feed gas having high CO concentration, high steam gas ratio and high pressure.

(125) Obviously, the above examples are merely illustrations clearly made, and not limited to the embodiments. For those skilled in the art, based on the above description, changes or alterations may be made in other different forms. All embodiments do not need to or cannot be exhaustive hereof. Obvious changes or alterations that is introduced thereof is still within the scope of the invention.