Methods for preparing high temperature water gas shifting catalyst, catalyst and process for reducing carbon monoxide

Abstract

The present invention deals with catalysts for the conversion of CO by the shifting reaction of high temperature water gas, free from chromium and iron, consisting of alumina promoted by potassium, by zinc and copper oxides and in a second embodiment also additionally nickel. The catalysts thus prepared maintain high CO conversion activity, not having the environmental limitations or operating limitations with low excess steam in the process, which exist for catalysts in accordance with the state of the art. Such catalysts are used in the hydrogen or synthesis gas production process by the steam reforming of hydrocarbons, allow the use of low steam/carbon ratios in the process, exhibiting high activity and stability to thermal deactivation and lower environmental restrictions for production, storage, use and disposal, than the industrially used catalysts based on iron, chromium, and copper oxides.

Claims

1. Method for preparing a water gas shift reaction catalyst, free of iron or chromium, comprising: a) Impregnating an alumina support with an aqueous solution of a potassium salt; b) Drying the support to remove the solvent and calcine the alumina support at temperatures between 400° C. and 800° C. to obtain a potassium promoted alumina, preferably forming potassium aluminate species; c) Impregnating the potassium promoted alumina with an aqueous polar solution containing a soluble zinc salt and a soluble copper salt; d) Drying at a temperature between 80° C. and 120° C., and calcining the material at temperatures between 300° C. and 500° C., to obtain a catalyst consisting of alumina promoted with potassium and containing zinc and copper oxides; e) Impregnating the material obtained in step (d) with an aqueous solution of a nickel salt, drying at a temperature between 80° C. and 120° C., optionally calcining between 350° C. to 450° C., to obtain a catalyst consisting of alumina promoted with potassium and containing zinc and copper oxides promoted by nickel.

2. Method, according to claim 1, wherein the alumina is selected from boehmite, gamma, theta-alumina or alumina promoted with lanthanum.

3. Method, according to claim 1, wherein the potassium salt is selected from hydroxide, nitrate or carbonate, the zinc salt is nitrate or carbonate and the copper and nickel salts are nitrates or acetates.

4. Method, according to claim 1, wherein the alumina support is simultaneously impregnated with potassium salt, zinc salt, copper salt and nickel salt in a polar aqueous solution, followed by drying at temperatures between 80° C. to 120° C., and calcination at temperatures between 300° C. to 500° C.

5. Catalysts, as obtained by the method defined in claim 4, wherein having a specific area greater than 60 m.sup.2/g, a potassium content between 4 to 15% m/m, zinc oxide content between 5 to 30% m/m, copper oxide content between 1 to 4% w/w, a Zn/Al molar ratio less than 0.4 and an atomic Cu/Ni ratio between 6 to 12, based on the weight of the catalyst.

6. Catalysts, as obtained by the method defined in claim 1, wherein having a specific area greater than 60 m.sup.2/g, a potassium content between 4 to 15% m/m, zinc oxide content between 5 to 30% m/m, copper oxide content between 1 to 4% w/w, a Zn/Al molar ratio less than 0.4 and an atomic Cu/Ni ratio between 6 to 12, based on the weight of the catalyst.

7. Process for reducing carbon monoxide, by the water-gas shift reaction, comprising contacting the catalyst of claim 6, with a synthesis gas containing between 5 to 30% v/v of CO, a vapor/dry gas ratio between 0.05 to 0.6 mol/mol, a reactor inlet temperature between 280° C. to 400° C., a reactor outlet temperature between 380° C. to 500° C. and an operating pressure in the range of 10 to 40 kgf/cm.sup.2.

8. Process, according to claim 7, wherein the synthesis gas contains between 8 to 20% v/v of CO, a vapor/dry gas ratio between 0.1 to 0.3 mol/mol, an inlet temperature in the reactor between 300° C. to 350° C. and a reactor outlet temperature between 400° C. to 450° C. and an operating pressure in the reactor in the range of 20 to 30 kgf/cm.sup.2.

9. Process, according to claim 7, wherein the water-gas shift reaction takes place in a fixed bed reactor containing two regions, wherein a first region comprises up to 40% v/v of the catalyst consisting of alumina containing potassium, and zinc and copper oxides promoted by nickel and a second region comprises a catalyst consisting of alumina containing potassium, and zinc and copper oxides.

10. Method for preparing high temperature gas shifting catalyst, wherein comprising the following steps: f) Impregnating an alumina support with an aqueous solution of a potassium salt; g) Drying the support to remove the solvent and calcine the support at temperatures between 400° C. and 800° C. to obtain a potassium promoted alumina, preferably forming potassium aluminate species; h) Impregnating the potassium promoted alumina with an aqueous polar solution containing a soluble zinc salt and a soluble copper salt; i) Drying at a temperature between 80° C. and 120° C., and calcining the material at temperatures between 300° C. and 500° C., to obtain a catalyst consisting of alumina promoted with potassium and containing zinc and copper oxides.

11. Catalysts, according to claim 10, wherein having a specific area greater than 60 m.sup.2/g, a potassium content between 3 to 10% m/m, zinc oxide content between 5 to 30% m/m, copper oxide content between 1 to 4% m/m, a Zn/Al molar ratio less than 0.4 based on the weight of the catalyst.

12. Process for reducing carbon monoxide, by the water-gas shift reaction, comprising contacting the catalyst of claim 11 with a synthesis gas containing between 5 to 30% v/v of CO, a vapor/dry gas ratio between 0.05 to 0.6 mol/mol, a reactor inlet temperature between 280° C. to 400° C., a reactor outlet temperature between 380° C. to 500° C. and an operating pressure in the range of 10 to 40 kgf/cm.sup.2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be described in more detail below, with reference to the attached figures which, in a schematic and non-limiting way, represent examples of the configuration thereof. In the drawings, there are:

(2) FIG. 1 illustrating an X-ray diffraction (XRD) graph of the solids obtained in accordance with Examples 1 and 9;

(3) FIG. 2 illustrating an X-ray diffraction (XRD) graph of solids obtained in accordance with Examples 10, 11 and 12.

DETAILED DESCRIPTION OF THE INVENTION

(4) The present invention deals with catalysts applicable to the water gas shifting step of the steam reforming process for the production of hydrogen. Such catalysts are constituted by a support of the alumina type promoted by potassium. The catalyst exhibits a specific area greater than 60 m.sup.2/g, a potassium content between 4 to 15% m/m, preferably between 3 to 10% m/m, a zinc oxide content between 5 to 30% m/m, preferably between 8 to 20% m/m, a copper oxide content between 1 to 4% m/m, preferably between 2 to 3% m/m, a Zn/Al molar ratio less than 0.4, preferably smaller 0.3 and an atomic Cu/Ni ratio between 6 to 12, preferably between 9 to 11, based on the oxidized material, being obtained by the preparation method comprising the following steps. 1. Impregnation of an alumina, selected from boehmite, gamma or theta-alumina with an aqueous solution of a potassium salt, preferably hydroxide, carbonate or nitrate, followed by drying and calcination at temperatures between 400° C. to 800° C., to obtain an alumina promoted with potassium; 2. Impregnation of the alumina-type support promoted with potassium with a polar solution, preferably aqueous, containing a zinc salt, preferably nitrate or carbonate, and a copper salt, preferably nitrate or acetate, followed by drying at temperatures between 80° C. to 120° C., formatting into pellets and calcining at temperatures between 300° C. to 500° C., preferably 450° C. 3. Optionally, the material obtained in item 2 can be impregnated with a polar solution, preferably aqueous, of a soluble nickel salt, preferably nitrate or acetate, followed by drying at temperatures between 80° C. to 120° C.

(5) The term potassium-promoted alumina, as used in the present invention, refers to an alumina containing potassium species on its surface, which may, depending on the calcination temperature, preferably exhibit X-ray diffraction technique, crystalline structures of aluminum and potassium oxide, such as the form K.sub.2O.Math.Al.sub.2O.sub.3(CAS 12003-62-3).

(6) Alternatively, step 1 does not need to be carried out, and commercial potassium aluminates can be used, as long as they have specific surface area greater than 15 m.sup.2/g, preferably greater than 40 m.sup.2/g. It is also advantageous to use promoted aluminas for greater resistance to loss of specific surface area by the action of steam, such as aluminas promoted by lanthanum.

(7) Alternatively, the material obtained in item 3 can be calcined in air at temperatures between 350° C. and 450° C., to avoid the release in the steam reforming process, during the entry into operation of the material of condensable gases with acidic properties.

(8) The formatting step can be carried out by commercial machines, obtaining inserts, preferably with typical dimensions of 3 to 6 mm in diameter and height. Other formats can also be used, such as single cylinder or multiple connected cylinders (trilobe, quadralobe) or raschig rings. Alternatively, it can be used in step 1 an alumina such as gamma or theta-alumina already pre-formatted.

(9) In an alternative form, the alumina support is simultaneously impregnated with a potassium salt, preferably potassium hydroxide or nitrate; a zinc salt, preferably zinc nitrate or carbonate; a copper salt, preferably copper nitrate or acetate and a nickel salt, preferably nickel nitrate and acetate, in a polar solution, preferably aqueous, followed by drying at temperatures between 80° C. to 120° C., and calcination at temperatures between 300° C. to 500° C.

(10) Although it is advantageous from the point of view of increasing the CO conversion activity in the water gas shifting reaction to use copper oxide contents above 4% m/m in the catalyst formulation, such contents bringing a significant temperature increase in the reactor during the start-up of the catalyst in the steam reforming process, due to the reduction of the copper oxide phase to metallic copper. Such temperature increase is undesirable because it can cause an early loss of performance of catalyst due to exposure to high temperatures, as well as reach values above the metallurgical limits of the reactor. Optionally, when conditions exist in the industrial plant to carry out the controlled reduction of the copper oxide phases, then copper oxide contents above 3% m/m can be used.

(11) The catalyst thus prepared is active, stable and ready to use, not requiring any additional activation procedure, and can be used in the conversion reaction of CO with water vapor to produce hydrogen, at reactor inlet temperatures between 280° C. to 400° C., preferably at temperatures between 300° C. to 350° C. and reactor outlet between 380° C. to 500° C., preferably between 400° C. to 450° C. The operating pressure in the reactor can be in the range from 10 to 40 kgf/cm.sup.2, preferably between 20 to 30 kgf/cm.sup.2. The vapor/dry gas molar ratio at the reactor inlet is preferably in the range of 0.05 to 0.6 mol/mol, more preferably in the range of 0.1 to 0.3 mol/mol. Similarly, the steam/carbon ratio (mol/mol) at the inlet of the primary steam reforming reactor, which precedes the high temperature water gas shifting reactor (HTS) is preferably in the range of 1 to 5 mol/mol, more preferably in the range of 1.5 to 2.5 mol/mol. The composition of the dry gas at the reactor inlet can typically contain CO contents between 5 to 30% v/v, preferably between 8 to 20% v/v.

(12) A second aspect of the present invention is to provide an HTS catalyst that can be used with low excess steam, equivalent to a steam/gas ratio at the inlet of the HTS reactor or steam/carbon at the inlet of the steam reforming reactor, positioned downstream the HTS reactor, without formation of by-products or increase in pressure drop due to the occurrence of phase transformations of the material.

(13) In the second aspect of the present invention, it is advantageous to use the catalyst consisting of alumina containing potassium, and zinc and copper oxides promoted by nickel, in the upper region of the fixed bed reactor and downward flow, more appropriately in the region comprised between 0 and 40% v/v in order to make use of its greater activity and reduce the risk of occurrence of methanation reactions with aging of the catalyst and at the bottom of the reactor the catalyst consisting of alumina containing potassium, and zinc and copper oxides.

(14) In a third aspect of the present invention is to provide a process for converting carbon monoxide by contacting said catalyst with a stream of synthesis gas at temperatures between 250° C. to 450° C., steam/gas between 0.2 to 1.0 mol/mol and pressures between 10 to 40 atm.

(15) In accordance with the first aspect of the invention there is taught a catalyst for use in the high temperature water gas shifting reaction (HTS) consisting of alumina containing potassium, zinc, copper and nickel species.

EXAMPLES

(16) The examples presented below are intended to illustrate some ways of implementing the invention, as well as to prove the practical feasibility of its application, not constituting any form of limitation of the invention.

Example 1

(17) This comparative example illustrates the preparation of a catalyst, in accordance with the state of the art, of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals. Initially, an aqueous solution containing 311 grams of demineralized water (H.sub.2O), 415 grams of aluminum nitrate (Al(NO.sub.3).sub.3.Math.9H.sub.2O, (Albrand VETEC, PA) in a nominal Zn/Al ratio of 0.5 mol/mol was prepared by dissolving and stirring at room temperature.

(18) Then, the solution was bulked with demineralized water to 830 ml and exhibited pH of 1.04. On top of this solution, an ammonium hydroxide solution (NH.sub.4OH, 28% w/w, VETEC) was added at room temperature, in 30 minutes and with stirring at 300 rpm, until the pH of the stirred mixture was between 8.0 to 8.5. The mixture was kept under stirring for 1 hour and then filtered and washed with demineralized water. The precipitated material was then dried at 110° C. for 1 night and then calcined in static air at a temperature of 750° C. for 3 hours.

(19) The material characterizations exhibited by the N.sub.2 adsorption technic (Brunauer-Emmett-Teller—BET method) a specific area of 65 m.sup.2/g, pore volume of 0.23 cm.sup.3/g and average pore diameter of 144 A; and by the X-ray diffraction technique (XRD, Cu—K radiation, 40 kV, 40 mA) the characteristic zinc aluminate pattern (JCPDS Card No 05-0669), as shown in FIG. 1.

Example 2

(20) This comparative example in accordance with the state of the art illustrates the preparation of a catalyst of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals. Ten grams of the material produced in EXAMPLE 1 were impregnated by the pore volume technique with 6.1 ml of an aqueous solution containing 0.145 grams of potassium hydroxide (VETEC). The material was dried at 100° C. for 1 hour and then calcined at 500° C. for 2 hours in order to obtain a zinc aluminate type catalyst promoted with 1% m/m of potassium. The product presented by the technique of adsorption of N.sub.2 a specific area of 60.7 m.sup.2/g, pore volume of 0.24 cm.sup.3/g and average pore diameter of 144.6 A.

Example 3

(21) This comparative example in accordance with the state of the art illustrates the preparation of a catalyst of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals. The preparation was identical to that used in EXAMPLE 2, the potassium hydroxide content being varied so as to have a nominal content of 2% m/m of potassium. The product presented by the technique of adsorption of N.sub.2 a specific area of 60.0 m.sup.2/g, pore volume of 0.24 cm.sup.3/g and average pore diameter of 143 A.

Example 4

(22) This comparative example in accordance with the state of the art illustrates the preparation of a catalyst of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals. The preparation was identical to that used in EXAMPLE 2, the potassium hydroxide content being varied so as to have a nominal content of 4% m/m of potassium. The product presented by the technique of adsorption of N.sub.2 a specific area of 52 m.sup.2/g, pore volume of 0.22 cm.sup.3/g and average pore diameter of 151 A.

Example 5

(23) This comparative example in accordance with the state of the art illustrates the preparation of a catalyst of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals. The preparation was identical to that used in EXAMPLE 2, the potassium hydroxide content being varied so as to have a nominal content of 8% m/m of potassium. The product presented by the technique of adsorption of N.sub.2 a specific area of 42 m.sup.2/g, pore volume of 0.19 cm.sup.3/g and average pore diameter of 181 A.

Example 6

(24) This comparative example in accordance with the state of the art illustrates the preparation of a catalyst of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals. The preparation was identical to that used in EXAMPLE 2, changing the source of potassium to potassium carbonate (K.sub.2CO.sub.3) in order to have a nominal content of 4% m/m of potassium. The product presented by the technique of adsorption of N.sub.2 a specific area of 39 m.sup.2/g, pore volume of 0.18 cm.sup.3/g and average pore diameter of 188 A.

Example 7

(25) This comparative example illustrates the preparation of a catalyst of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals, and in accordance with the state of the art. The material was prepared in a similar way to EXAMPLE 1, except that the ratios of the reactants were changed in order to have a Zn/Al ratio of 0.70 mol/mol.

(26) The material characterizations exhibited a) by the N.sub.2 adsorption technique a specific area of 22 m.sup.2/g, pore volume of 0.12 cm.sup.3/g and average pore diameter of 235; b) by the technique without quantitative X-ray Fluorescence (FRX) a composition containing 25% m/m of Al and 40% m/m of Zn, with the oxygen balance and the technique of X-ray diffraction (XRD) as the standard characteristic of zinc aluminate, as shown in FIG. 1.

Example 8

(27) This comparative example in accordance with the state of the art illustrates the preparation of a catalyst of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals. Ten grams of the material produced in EXAMPLE 7 were impregnated by the pore volume technique with 4.0 ml of an aqueous solution containing 0.598 grams of potassium hydroxide (VETEC). The material was dried at 100° C. for 1 hour and then calcined at 500° C. for 2 hours in order to obtain a zinc aluminate type catalyst promoted with 4% m/m of potassium. The product presented by the technique of adsorption of N.sub.2 a specific area of 16.7 m.sup.2/g, pore volume of 0.10 cm.sup.3/g and average pore diameter of 173 A.

Example 9

(28) This comparative example in accordance with the state of the art illustrates the preparation of a catalyst of high temperature water gas shifting (HTS) of the zinc aluminate type promoted by alkali metals. The preparation was identical to that used in EXAMPLE 8, the potassium hydroxide content being varied so as to have a nominal content of 8% m/m of potassium. The product presented by the technique of adsorption of N.sub.2 a specific area of 17.5 m.sup.2/g, pore volume of 0.08 cm.sup.3/g and average pore diameter of 176 A.

Example 10

(29) This example illustrates the preparation of a high temperature water gas shifting (HTS) catalyst of the alumina type promoted with potassium and zinc oxide in accordance with the present invention. One hundred grams of a commercial alumina hydroxide (boehmite, CATAPAL, SASOL) were impregnated by the wet point method with a 70 ml aqueous solution containing 11.5 grams of potassium hydroxide (VETEC). The following material was dried at 100° C. for 1 night and calcined in static air at a temperature of 600° C. for 2 hours to obtain a SUPPORT of the alumina type promoted with potassium, as shown in FIG. 2. The material had a specific area of 111 m.sup.2/g and pore volume of 0.27 cm.sup.3/g by the nitrogen adsorption technique (BET).

(30) Fifteen grams of the support thus obtained were impregnated using the wet spot technique with 9.3 ml of aqueous solution containing 6.09 grams of zinc nitrate (Zn(NO.sub.3).sub.2.Math.6H.sub.2O, Merck) and then dried at 100° C. for 1 night and calcined in static air at a temperature of 400° C. for 2 hours, to obtain a material having a nominal content of 8.0 m/m of Zn (the semiquantitative analysis by the X-ray fluorescence technique showed a content of 7.1% m/m), a specific area of 89.5 m.sup.2/g and a pore volume of 0.21 cm.sup.3/g and without observing the significant presence of crystalline zinc aluminate by the X-ray diffraction technique, as illustrated in FIG. 2.

Example 11

(31) This example illustrates the preparation of a high temperature water gas shifting (HTS) catalyst of the alumina type promoted with potassium, and zinc and copper oxide, and in accordance with the present invention. One hundred grams of a commercial alumina hydroxide (boehmite, CATAPAL, SASOL) were impregnated by the wet point method with a 70 ml aqueous solution containing 11.5 grams of potassium hydroxide (VETEC). The following material was dried at 100° C. for 1 night and calcined in static air at a temperature of 600° C. for 2 hours to obtain a SUPPORT of the alumina type promoted with potassium, as shown in FIG. 2. The material had a specific area of 111 m.sup.2/g and pore volume of 0.27 cm.sup.3/g by the nitrogen adsorption technique (BET).

(32) Fifteen grams of the support thus obtained were impregnated using the wet spot technique with 9.3 ml of aqueous solution containing 6.30 grams of zinc nitrate (Zn(NO.sub.3).sub.2.Math.6H.sub.2O, Merck) and 1.57 grams of copper nitrate (Cu(NO.sub.3).sub.2.Math.3H.sub.2O, VETEC) and then dried at 100° C. for 1 night and calcined in static air at a temperature of 400° C. for 2 hours to obtain a material containing nominally 10% ZnO and 3.0% CuO (a semiquantitative analysis by X-ray fluorescence resulted in 3.6% K, 7.3% m/m Zn and 2.4% m/m Cu). The catalyst had a specific surface area of 88.3 m.sup.2/g and pore volume of 0.21 cm.sup.3/g.

Example 12

(33) This comparative example illustrates the preparation of a high temperature water gas shifting catalyst (HTS) of the alumina type containing potassium, zinc and copper oxides, and promoted by nickel salts and in accordance with present invention. The material was prepared according to EXAMPLE 11 and then impregnated by the wet point method with an aqueous solution of nickel nitrate (Ni(NO.sub.3).sub.2.Math.6H.sub.2O) in order to obtain an atomic Cu/Ni ratio of 10 atg/atg. A part of the material was only dried at 100° C. for 1 night to obtain the catalyst identified as EXAMPLE 12-S and another portion was calcined at the temperature of 400° C. for 2 hours to obtain the catalyst identified as EXAMPLE 12-C.

Example 13

(34) This example describes the measure of catalytic activity of the catalysts obtained according to EXAMPLES 1 TO 12. The shift reaction was carried out in a fixed bed reactor, at atmospheric pressure. The sample was initially heated in argon flow up to 100° C. and then up to 350° C., at a rate of 5° C./min in a flow of 5% H.sub.2 in argon saturated with water vapor at 73° C. After this pre-treatment, the gas mixture was replaced by a mixture containing 10% CO, 10% CO.sub.2, 2% methane in balance of H.sub.2, keeping the temperature of the saturator with water at 73° C., corresponding to a ratio steam/gas of 0.55 mol/mol. The reaction was carried out at temperatures from 350° C. to 450° C. with the reactor effluent being analyzed by gas chromatography. Catalyst activity was expressed as CO conversion (% v/v).

(35) The results are shown in Table 1 and allow to conclude that: a) the catalyst based on alumina containing potassium and zinc oxide, in accordance with the present invention, (EXAMPLE 10) has CO conversion activity by the water gas shifting reaction greater than materials prepared in accordance with the state of the art (EXAMPLES 1 to 9); b) the addition of a low copper content to the alumina-type catalyst containing potassium and zinc oxide and in accordance with the present invention (EXAMPLE 11) allows to obtain a significant increase in the CO conversion activity, the performance being greater than that observed for a commercial HTS catalyst consisting of iron, chromium and copper oxides.

(36) TABLE-US-00001 TABLE 1 Activity in the water gas shifting reaction (XCO) of HTS catalysts prepared in accordance with the state of the art and in accordance with the present invention. Temperature (° C.) 350 370 390 420 450 catalyst K Zn Cu Ni X CO X CO X CO X CO X CO Zn/Al Area % % % % % % % % % mol/mol m.sup.2/g m/m m/m m/m m/m v/v v/v v/v v/v v/v EXAMPLE 1 0.5 65.0 0.0 35.6 0.0 0.0 0.3 0.5 0.5 1.4 2.3 EXAMPLE 2 0.5 60.7 1.0 35.2 0.0 0.0 0.2 1.4 1.9 3.1 3.5 EXAMPLE 3 0.5 60.0 2.0 34.9 0.0 0.0 3.1 4.5 6.3 9.9 12.7 EXAMPLE 4 0.5 52.0 4.0 34.2 0.0 0.0 4.5 6.4 9.7 16.0 22.9 EXAMPLE 5 0.5 42.0 8.0 33.0 0.0 0.0 3.5 6.2 9.8 16.3 23.1 EXAMPLE 6 0.5 39.0 4.0 34.2 0.0 0.0 3.2 6.1 9.2 15.8 23.3 EXAMPLE 7 0.7 22.0 0.0 42.1 0.0 0.0 0.1 0.3 0.4 1.0 1.5 EXAMPLE 8 0.7 16.7 4.0 40.5 0.0 0.0 3.1 5.7 9.7 17.0 27.2 EXAMPLE 9 0.7 17.5 8.0 39.0 0.0 0.0 2.1 3.9 7.6 14.1 21.6 EXAMPLE 10 0.1 111.0 9.0 8.0 0.0 0.0 1.4 2.0 16.2 26.6 29.6 EXAMPLE 11 0.1 89.5 8.7 7.0 2.4 0.0 40.0 49.8 54.7 60.1 59.0 commercial — n.a. 0 0 0 25.5 Note: Commercial HTS catalyst consisting of iron and chromium oxides promoted by copper oxide.

Example 14

(37) This example describes the thermal deactivation resistance of the catalysts obtained in accordance with EXAMPLES 1 to 12. The shift reaction was carried out in a fixed bed reactor, at atmospheric pressure. The sample was initially heated in argon flow up to 100° C. and then up to 350° C., at a rate of 5° C./min in a flow of 5% H.sub.2 in argon saturated with water vapor at 73° C. After this pre-treatment, the gas mixture was replaced by a mixture containing 10% CO, 10% CO.sub.2, 2% methane in balance of H.sub.2, keeping the temperature of the saturator with water at 73° C., corresponding to a ratio steam/gas of 0.55 mol/mol. The reaction was carried out at temperatures of 350° C. (X1) and then a first deactivation cycle was carried out exposing the catalyst to a flow of H.sub.2/vapor for 6 hours at 500° C. Next, the second measurement of the CO conversion activity at 350° C. (X2) was performed as previously performed. The deactivation and reaction cycle was repeated and the activity at 350° C. was measured a third time (X3). The activity of catalyst was expressed as CO conversion (% v/v).

(38) TABLE-US-00002 TABLE 2 Activity in the water gas shifting reaction (XCO) of the HTS catalysts prepared in accordance with the present invention. X1 X2 X3 (350° C.) (350° C.) (350° C.) catalyst K Zn Cu Ni X CO X CO X CO Zn/Al Area % % % % % % % mol/mol m.sup.2/g m/m m/m m/m m/m v/v v/v v/v EXAMPLE 11 0.1 89.5 8.7 7.0 2.4 0.0 34.2 20.3 13.9 EXAMPLE 12-S 0.1 87.6 8.7 7.0 2.4 0.2 57.7 30.3 22.1 EXAMPLE 12-C 0.1 88.4 8.7 7.0 2.4 0.2 45.4 24.5 18.1 commercial — n.a. 0 0 0 25.5 6.2 5.0 Note: Commercial HTS catalyst consisting of iron and chromium oxides promoted by copper oxide.

(39) The results in Table 2 show that the catalysts according to present invention (EXAMPLES 11, 12-S and 12-C) are able to retain activity much greater than the commercial catalyst taken as reference and based on iron, chromium and copper oxides, when exposed to accelerated deactivation methodology by exposure to elevated temperatures. Promotion with nickel salt without carrying out the calcination step (EXAMPLE 12-S) allows to obtain the best results, but the material containing nickel and subjected to calcination (EXAMPLE 12-C) can be advantageous considering aspects of transport, storage and activation in the industrial plant. The presence of nickel in the formulation with a Cu/Ni ratio close to 10 also allowed to obtain an increase in activity and resistance to deactivation by exposure to high temperatures, without observing in the conditions of the experiments the formation of methane contents from the reaction reactions. The catalyst, therefore, demonstrates to be suitable for industrial use and, due to its high activity, allows the use of reactor inlet temperatures lower than those currently practiced with conventional HTS catalysts based on iron, chromium and copper oxides, with potential advantage of greater energy efficiency in the steam reforming process and longer catalyst campaign time.

(40) It should be noted that, although the present invention has been described with respect to the attached drawings, modifications and adaptations can be made by those skilled in the art, depending on the specific situation, but provided that it is within the inventive scope defined herein.