JPS5929037A - Modified copper-zinc contained catalyst and production of methanol by using same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises copper, zinc, and a metal selected from the group consisting of yttrium, lanthanide elements, actinide elements and mixtures thereof, - carbon oxide and hydrogen (83'ng
aB+synthesis gas) to methanol.

There are a number of prior disclosures regarding copper- and/or zinc-containing catalysts that are more or less related to those of the present proposal, some of which also describe their use in the conversion of synthesis gas to methanol. Perhaps most relevant is US Pat. No. 3,73g, tl, 77, which discloses copper, zinc and didymium oxide containing catalysts suitable for converting carbon oxides and hydrogen to methanol. This catalyst is about s's"c-qoo
It is produced by co-precipitation of nitrates at a temperature of C. No particular pH is indicated as critical.

The present invention particularly relates to modified catalyst compositions having very high activity for the production of methanol as described above.

The present invention therefore includes copper, zinc, and a rare earth metal modifier selected from the group consisting of yttrium, lanthanide elements, actinide elements, and mixtures thereof, the amount of said modifier being calculated as the metal in the total catalyst composition. l based on
Or 2! % by weight and the relative proportions of copper and zinc are calculated as % by weight of the metal /:10 to 20:l
A catalyst composition comprising a) copper, zinc and. Modifier. salt. aqueous solutions of alkali metal carbonates are simultaneously co-mixed at a temperature of t5°C to tjoC, while maintaining the pH between 5.5 and 7.5, thereby forming a precipitate; b) washing the precipitate; , dried and smoked at a temperature ranging from 200°C to IIo o “c; and C) /7! in a hydrogen-containing atmosphere;
``C to aOOoC. It exhibits a substantially higher activity than catalysts known from the prior art, such as those described above.

In the above, lanthanide elements are seven of the lanthanum series elements, including elements with atomic numbers j7 (lanthanum) to 7/(lutetium), while actinide elements include elements with atomic numbers greater than 9 and 100. It is one of the actinium series elements. The higher numbers do not actually make satisfactory catalyst modifiers because of their scarcity, radioactivity and short lifetime. Of interest in the actinium series are elements with atomic numbers 9 to 92, especially those of qO to octopus, especially thorium and uranium, and most preferably thorium. Mixtures of promoter elements may also be utilized where appropriate. Mixed metals are readily available commercially, especially for the lanthanum series (rare earths). A suitable example of a commercially available mixed metal is the so-called 6-didimetal.
/ Described in Specification No. 7. Another commercially available rare earth formulation is known as 6-metal. Other rare earth mixtures are also available.

The exact amount of denaturant is not critical. Generally, / to 25% by weight calculated as metal based on the total catalyst composition
The amount of catalyst paternal agent is satisfactory, and the amount of catalytic fathering agent is
Catalyst modifier amounts of I% to 75% by weight are preferred.

The relative proportions of copper and zinc used in the catalyst composition can vary. Generally calculated as metal weight % l: IO to 20
Preferred catalyst compositions in which the ratio of :/ is satisfactory and the ratio of l:/ to io:i, calculated on the same basis, are preferred are those in which the modifier is from the group consisting of yttrium, elemental lanthanides, thorium and mixtures thereof. It is the chosen one. In other preferred compositions the modifier is praseodymium, neodymium, samarium, cerium, yttrium, lanthanum or thorium.

The initial form in which the copper, zinc and modifier are used is preferably an oxide. However, compounds which are easily converted into oxides, such as the corresponding metal carbonates, are also suitably used initially. This is because they are converted into oxides, for example during the pretreatment after the formation of the initially prepared catalyst composition. Pretreatment of the catalyst in hydrogen and operation of the catalyst in a reaction environment will result in at least a partial reduction of some of the metals to a lower oxidation state. It is intended that these reduced forms of the catalyst also fall within the scope of the present invention.

In order to give a high activity, the compositions of the invention are manufactured in a very specific manner. Generally, the compositions are prepared by coprecipitating the metals from solutions of their salts in the form of/or more compounds that can be readily converted to oxides. The salt is preferably a nitrate salt or is converted to a nitrite by the use of nitric acid to promote dissolution of non-nitrates. Precipitation is carried out using an aqueous alkali metal carbonate solution co-mixed with the metal salt solution at a given pH and a given temperature. In a preferred embodiment of the present invention, copper,
Zinc and the denaturant nitrate are dissolved in water. A small amount of nitric acid is used to promote dissolution of non-nitrate compounds such as carbonates and oxides. Another solution is prepared by dissolving an alkali metal carbonate, preferably potassium or sodium carbonate, in water. The λ solutions are then heated to the desired mixing temperature and simultaneously S, S to 7.5, preferably 6.0 to 7.0, more preferably 6.3 to 6.
l) H in the range of 7 is metered into the stirred settling tank in respective proportions such that a range of l) H is maintained in the settling tank. The desired precipitation temperature is Il, j″C to f j ″C, preferably jO
oC to gOoCl, preferably 50°C to 70°C
℃ range. The precipitate thus obtained is a mixture of carbonates, basic carbonates and hydroxides. This is then collected, washed until substantially free of electrolyte, then dried and dried at 200°C to IIoo°C as previously described.
, preferably at a temperature of 2jO°C to 300°C. Drying is carried out at a temperature sufficient to remove water. This step is conveniently combined with the firing step by suitably programming the temperature from room temperature gradually through the drying temperature and then to the smoldering temperature. The smoked material is shaped, for example, by pressurizing it into pellets using guguphite as a lubricant. The oxide mixture is pretreated in a hydrogen-containing atmosphere to bring it to its most active state before it is used as a catalyst.

Pretreatment is accomplished by contacting the catalyst with a stream of hydrogen or hydrogen mixed with an inert gas or diluent at a temperature in the range of 775°C to 1100°C. Suitable diluent gases for the activated gas mixture include nitrogen or carbon oxides.

Although for some applications it may be preferable to use catalysts on inert supports such as silica and/or alumina, in many variations it is preferable to use unsupported contacts.

In accordance with the above, the present invention takes into account the catalyst composition proposed herein, the method for its preparation, and the technological progress obtained thereby: - a mixture of hydrogen and carbon monoxide (synthesized) in the presence of said catalyst composition; It also includes a method for producing methanol from gas) as well as methanol produced by the latter method. In general, the last two aspects mentioned will be the subject of the text that follows.

By doing so, an improved method for producing methanol is obtained. The molar ratio of hydrogen and carbon oxides is 0.5:l to 2
0:/, preferably 22/ to 10:/. Preferably, the molar ratio of hydrogen to carbon monoxide is 2:/or higher. Carbon dioxide may be present in the reaction mixture in an amount up to 50% by weight. The reaction temperature is Over 325″C, pressures range from atmospheric to IOA oo.

over kPa. The gas hourly space velocity is 2! ;
, 000 h.

The catalyst composition may be used in a batchwise operation or continuously by passing the reactants through a tubular reactor containing the catalyst and maintained at reaction temperature.

After the reaction, the product mixture is separated and the methanol is recovered by conventional methods such as selective condensation or selective adsorption.

The present invention will be illustrated by the following specific examples, which are provided for illustrative purposes only and should not be construed as limiting the invention.

Example 1 Cu(Non)2・JH20/20.79 and Zn
(NOs)*4 (7) was added to 500-mL of water. A mixture of rare earth carbonates (Mo1y0orp, !0% LaS
/, 2%Nd, Hiro%Pr52%%sm>ti,,i
9 was added to water SO-, to which nitric acid 3.5- was gradually added to promote dissolution of the carbonate compounds. This latter solution was added slowly to the copper/zinc solution followed by enough water to make one liter of solution. A 1 molar solution of sodium carbonate was prepared. Heat both solutions to 5°C and! The two solutions were individually weighed into a liter stirred beaker at a temperature of 200°C to form a slurry with a pH of 6. After adding the copper-zinc-rare earth metal solution to the beaker,
The IJ solution was stopped, and the precipitate was then filtered and washed with 20 liters of water.

The precipitate was then dried in a vacuum oven for 76 hours. The dried precipitate was charged into a large glass tube reactor and the material was smoldered by heating gradually to 2 °C for t hours under an upward flow of air. The composition was then activated in hydrogen at 1000 d/min at a temperature up to 225°C. The resulting catalyst composition is referred to as Example 1 in Table 1 which also describes its use in the production of methanol from syngas.

Comparative Example A A comparative example was prepared according to the teachings of U.S. Pat. No. 3,75+tI/7. The first solution was prepared by dissolving 95 g of IJ carbonate in 1 liter of water.

The second solution contains 0u(No3)*/20.79, Zn(
NOa)s l=Og, mixture of rare earth carbonates as described in Example 111. / 9 with water jO- and nitric acid 3. Prepared by dissolving in J-. Water was then added to the second solution to make up 1 liter. Both solutions were then heated to qo@c and the second solution was quickly mixed into the first solution within 15 minutes with rapid stirring. During the precipitation that occurred, the pH ranged from O to 7.5 at the final stage of precipitation. The precipitate was then washed 16 times with 1 liter of water and heated to 720 ml at 3.11 kPa.
Dry in a vacuum oven at °C for 76 hours. The precipitate was then charged into a large glass tube reactor and the material was calcined by heating gradually to 265 DEG C. for 16 hours under an upward flow of air.

Next, the smoked material was heated to 100,100 O at a temperature of 225"C.
Activated in hydrogen for minutes.

Comparative Example B Another comparative example was prepared similar to that of Example A above, except that the order of addition of the solutions was reversed, ie, the sodium carbonate solution was added to the metal nitrate solution. In this example, the smoldering was carried out with a 2:l (by volume) nitrogen/hydrogen mixture at 200 tnl/min.

A comparative example was produced in the same manner as Example B except that the smoking was performed using 1.00 ton for 17 minutes.

Comparative Example This example was prepared in the same manner as Example B above, except that the smoking was carried out with 1100 tnl/min of hydrogen.

Comparative Example B This comparative example involves a two-step precipitation process. A solution of rare earth and zinc nitrates was precipitated with sodium carbonate at 70 °C, and then a solution of copper and zinc nitrates was added to this precipitation slurry, and the resulting mixture was further precipitated with additional sodium carbonate at 70 °C. I let it happen.

Comparative Example F This comparative example was prepared in the same manner as Example F except that the second precipitation was carried out in ZajoC. - Example 2 The catalysts prepared above were tested for their activity towards the conversion of synthesis gas to methanol. To perform this comparison, the catalyst composition was packed into a tube reactor. A mixture of hydrogen and carbon monoxide in a molar ratio of 2 parts/mol was introduced into the reactor at a temperature of 300"C and a flow rate shown in Table 1. The analysis of the liquid product is also shown in Table 1.

As can be seen from this table, the catalysts of the present invention contain catalysts prepared according to the teachings of Il/7, for example in U.S. Pat. gives a much higher liquid product yield than Example A) in this specification.

Example 3-1/A further catalyst was produced in the same manner as described in Example/A above and Comparative Example A. 21 IO for their activity towards the conversion of synthesis gas to methanol in the above method.
Tested at a temperature of °C. The results are shown in Table 2.

(Margin below) Table l Mu /, ( 0,.

0, I Oo.

0° 0,.

215-

Claims (10)

[Claims] (1) Copper, zinc, and a rare earth metal modifier selected from the group consisting of yttrium, lanthanide elements, actinide elements, and mixtures thereof, the amount of the modifier being calculated as metal based on the total catalyst composition. Shit/72ishi2
5% by weight and the relative proportions of copper and zinc are /:IO to 20:/, calculated as metal weight %, comprising: a) an aqueous solution of copper, zinc and modifier salts; and an aqueous solution of alkali metal carbonate at a temperature of +t"c to IrjoC while maintaining the pH between 3.3 and 7.5, thereby forming a precipitate; b) washing and drying the precipitate; and C) activating in a hydrogen-containing atmosphere at a temperature ranging from /7S''C to 100°C. Said composition. 2. The composition of claim 1, wherein the modifier is present in the composition in an amount of from 1 to 75% by weight, calculated as metal, based on the total catalyst composition. (3) A composition according to claim 1 or 2, wherein copper and zinc are present in the composition in a weight ratio ranging from 1:1 to 1O:1. (4) The composition according to any one of claims 1 to 3, wherein the modifier is selected from the group consisting of yttrium, elemental lanthanides, thorium, and mixtures thereof. (5) The modifier is praseodymium, neodymium, samarium,
The composition according to any one of claims 1 to 3, which is cerium, yttrium, lanthanum or thorium. (6) Simultaneous co-mixing with pH in the range of 0 to 7.0
A set of chrysanthemums according to any one of claims 1 to 5. (7) The composition according to claim 1, which has a pH in the range of 6.3 to 7. (8) The composition according to any one of claims 1 to 7, wherein the simultaneous co-mixing is carried out at a temperature of jOoC to gOoC. (9) Temperature! The composition □ according to claim 1, wherein the temperature is from 0°C to 70°C. (10) The composition according to any one of claims 1 to 9, wherein the copper, zinc, and modifier are in the form of nitrates. 01) A composition according to any one of claims 1 to 9, wherein the copper, zinc and modifier are at least partially in the form of oxides. (B) Excluding Comparative Examples (compositions described specifically in relation to Examples). 03) A method for producing a catalyst composition according to claim 72. 04) A method for producing methanol from a mixture of hydrogen and carbon monoxide in the presence of the catalyst composition according to any one of claims 1 to 12.