JPS61249939A - Production of oxygen-containing 2c compound - Google Patents

Abstract

PURPOSE:To improve the selectivity of an oxygen-containing 2C compound such as ethanol, acetaldehyde, acetic acid, etc., CO and H2, by carrying out the reaction in the presence of a Co catalyst modified with Ru and an alkaline earth metal. CONSTITUTION:An oxygen-containing 2C compound is produced by reacting CO with H2 in the presence of a Co catalyst modified with Ru and an alkaline earth metal. The compositional ratio of the catalyst is 1/10-10pts.wt. of the alkaline earth metal per 1pt.wt. of Co in terms of metal. The catalyst can be produced by impregnating solutions of a cobalt compound (e.g. cobalt nitrate), a Ru compound (e.g. ruthenium chloride) and alkaline earth metal compound successively or at the same time to a carrier or by the ion-exchange process, dry-mixing process, etc. The catalyst is preferably reduced in H2 or CO atmosphere before reaction. EFFECT:The selectivity of the objective compound can be improved remarkably by the addition of the above elements.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to producing ethanol by reacting carbon oxide with hydrogen under a cobalt catalyst modified with at least one element selected from ruthenium and alkaline earth metals. , acetaldehyde, acetic acid, and other oxygen-containing compounds having 2 carbon atoms (C2 oxygen-containing compounds).

Rhodium catalysts with certain co-catalysts are already known for the direct production of C2 oxygenated compounds such as ethanol, acetaldehyde, acetic acid and acetic esters from synthesis gas (German Patent Application No. 250.233. Showa 5
1-80806 and JP-A-52-14706). However, this catalyst has the disadvantage that it cannot be used in large quantities because rhodium is expensive and is a valuable resource that exists only in small quantities on earth. Therefore, there is a strong desire to develop an inexpensive catalyst that does not require the use of rhodium.

In addition, it is known that inexpensive cobalt-based catalysts are active in synthesis gas reactions (Fischer-Tropsch reactions), but the main products in this case are hydrocarbons and oxygenated compounds. The amount produced is extremely small.

Recently, cobalt catalysts modified with copper, chromium, zinc, alkaline earth metals, aluminum, rare earths or iron (
French Patent No. 4,122,110 and German Patent Application No. 2,748,097') and cobalt catalysts modified with gold and/or silver and/or rhenium (European Pat. −
25124) was announced. Although these catalysts produce oxygenated compounds, they are very delicate in their production and operation. Therefore, they generally require special and advanced techniques for production and operation, and the life of the obtained catalyst is also short.

Therefore, it is a challenge in the art to develop catalysts that are easy to prepare, robust, long-lived, and provide O2 oxygenates from synthesis gas with high selectivity.

As a result of intensive research, the present inventors have discovered that the activity of producing C2 oxygen-containing compounds can be essentially enhanced by modifying cobalt with ruthenium. Furthermore, it has been found that the selectivity of C2 oxygen-containing compounds can be dramatically increased by adding at least one element selected from alkaline earth metals in addition to ruthenium as a promoter. Therefore, the present invention provides a method for producing a C2 oxygen-containing compound from carbon monoxide and hydrogen using a cobalt catalyst, characterized in that the catalyst contains at least one of ruthenium and an alkaline earth metal in addition to cobalt. It's a method.

The fact that the selectivity of C2 oxygenates is significantly improved by the addition of the above-mentioned elements was indeed surprising and could not have been foreseen. It is also not clear why the main products of the syngas reactions on oak, cobalt and ruthenium catalysts, respectively, are hydrocarbons. However, what plays a central role in its activity is essentially the elemental species that coexist with each other, and therefore there is no restriction in principle on the form of the catalyst itself or the form of each component in the catalyst. Further, although each component of the catalyst may be used without a carrier, it is usually preferable to use it by supporting it on a carrier. That is, it is prepared by a so-called impregnation method, in which a solution of a cobalt compound, a ruthenium compound, and a compound of at least one element selected from alkaline earth metals is immersed onto the carrier sequentially or simultaneously, and then the solvent is removed. Alternatively, it may be prepared by an ion exchange method or a so-called dry mixing method.

Cobalt compounds used in catalyst preparation include, for example, inorganic acid salts such as cobalt nitrate, cobalt chloride, cobalt bromide, cobalt iodide, cobalt carbonate, and cobalt T sulfate, as well as cobalt formate, cobalt acetate, and cobalt oxalate. Organic acid salts, oxides, cobalt carbonyl, etc. are suitable. Similarly, examples of ruthenium compounds include inorganic acid salts such as ruthenium chloride, ruthenium bromide, ruthenium iodide, ammonium ruthenate chloride, ruthenium nitrate, and ruthenium hydroxide, and organic acids such as ruthenium acetate, ruthenium formate, and ruthenium oxalate. Salts, oxides, ammine complex salts, clusters, organic complex compounds, etc. are used. Compounds of alkaline earth metal elements, namely beryllium, magnesium, calcium, strontium, barium, and radium, include inorganic acid salts such as fluorides, chlorides, bromides, iodides, nitrates, sulfates, carbonates, and hydroxides. , organic acid salts such as formate, acetate, etc. are used.

However, in order to make it easier to support these compounds on a carrier, water or other suitable solvents may be used.In the catalyst of the present invention, the component composition ratio is 1 part by weight of cobalt, 1 part by weight of cobalt, and 1 part by weight of alkaline earth. It is a metal part.

In carrying out the present invention, it is preferable that the catalyst is previously subjected to a reduction treatment in an atmosphere of hydrogen or carbon monoxide. The raw material synthesis gas may contain inert components such as argon, nitrogen, and carbon dioxide in addition to carbon monoxide and hydrogen.

In particular, the mixture of ethanol, acetaldehyde, etc. that is produced as the main component in this method can be easily separated and purified by distillation, so it is practical as a manufacturing process for these products, and it also contributes greatly to the conservation of petroleum resources. It is expected that

The present invention will be explained in more detail below using Examples and Comparative Examples.

Example 1 Commercially available silica gel carrier (Davison+57. Specific surface area 250
~350m/9, pore volume 0.95~120m1/17
．． Apparent specific gravity 0.35~0.43117Fill) 10
g, Co (OAC)2・4H202,119yoU
The cobalt-magnesium-silica catalyst (I ) was obtained. Furthermore, this is Ru3 (Co)tz O,571
The cobalt-ruthenium-magnesium-silica catalyst (n) was immersed in an n-hexane solution, and the solvent was removed and dried.
I got it. 3d of this catalyst (II) was added to a fixed-bed high-pressure flow reactor (5O8-31611!, inside diameter 11 mm)
and hydrogen reduction was performed at 450°C in a hydrogen stream. After reduction, synthesis gas (-carbon oxide: hydrogen: albo: /=30
:60:10, volume ratio) t 20 kll/an" (gauge pressure) and brought into contact with the catalyst at a space velocity of 2,000/h. All the products were introduced in a gaseous state into a gas chromatograph for analysis. did.

Example 2゜Similarly to Example 1, 1 og of silica gel carrier, Co (OA
C) 2・4H202,11,! lit, Ca (OA
C) 2-H2O1,011 and R”5(CO)lz
0.57 g of yoricobalt A and thenium-calcium-silica catalyst (I[I) were obtained. The catalyst (Iff) was pretreated and reacted in the same manner as in Example 1.

Example 3 Same as in Example 1, 1.22 g of silica gel carrier 10I and 1.0.57 g of Ru3(CO), ruthenium-strontium-silica catalyst (
IV) was obtained. The catalyst <rv> was pretreated and reacted in the same manner as in Example 1.

Example 4, similar to Example 1, silica gel carrier 10,9, CO (OA
C) 2 ・4H202,11Jil, Ba (OA
C) 22.119 k and Ru3(CO) 120.57
9 yo9 Kohar)-kf nium-barium-silica catalyst (V) was obtained. The catalyst (V) was pretreated and reacted in the same manner as in Example 1.

Comparative Example 1゜The same silica gel carrier loy as in Example 1 was used as Co(OA
C) 2.4HzO2,11Ji' O aqueous solution 12I11
The cobalt-silica catalyst (VI) was prepared by immersing it for 1K and drying by removing the solvent using a rotary evaporator, and pretreated and reacted in the same manner as in Example 1.

Comparative Example 2 10 g of the same silica gel carrier as in Example 1 was mixed with Ru5 (C
o) tz 0.571 (D n-he*+17 in solution
CFla, and the solvent was removed and dried using a rotary evaporator to obtain a ruthenium-silica catalyst (■). catalyst(
(2) was subjected to pretreatment and reaction in the same manner as in Example 1.

Comparative Example 3゜The same silica gel carrier as in Example 1 was used as F3r 0A.
C) 12 tons of aqueous solution of z + n, o 1.22 J'
17 CF in l! The solvent was removed and dried using a rotary evaporator, and the strontium-silica catalyst (V
ll) was obtained. The catalyst (■) was treated as it was in Example 1, and the silica gel carrier 1011Co (
OAC)z ・4HzO2,1111Oj and Rua (
A cobalt-ruthenium catalyst (IX) was obtained from 7 g of Co)12o,s. Catalyst (IX) t-Pretreatment and reaction were performed in the same manner as in Example 1.

Next, the experimental results are shown in the following table.

Each code shown in the table indicates the following.

(a) Reaction conditions: Raw material synthesis gas A r : Co :
H2 = 10:30:60, pressure 20 to 9/art”
(gauge pressure), space velocity 2.000/h0 (cut-oxidation carbon conversion rate (chi) (C) product carbon efficiency (%) (6) Other hydrocarbons include C, C, etc. Become.

(e) C2 oxygenated compound represents the sum of ethanol, acetaldehyde, acetic acid and acetic acid ester.

Claims (1)

[Claims] (1) A method for directly producing an oxygen-containing compound having 2 carbon atoms from carbon monoxide and hydrogen using a catalyst, wherein the catalyst contains both cobalt and ruthenium, and further includes at least one element selected from alkaline earth metals. A method characterized by containing an element.