JPS5945660B2 - Method for producing oxygenated lower hydrocarbons - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing oxygenated lower hydrocarbons from a mixture of carbon monoxide and hydrogen.

More specifically, in the presence of a catalyst consisting of an iridium carbonyl compound and a valent organophosphorus compound,
This invention relates to a method for directly producing oxygen-containing lower hydrocarbons such as ethylene glycol and methanol by reacting a mixture of carbon monoxide and hydrogen. As a method for producing oxygen-containing lower hydrocarbons, especially ethylene glycol, from a mixture of carbon monoxide and hydrogen, a method of reacting under high temperature and high pressure conditions in the presence of a catalyst containing an element of group Ⅰ of the periodic table is conventionally known. be. Among them, it is known from JP-A No. 51-36403 that a catalyst containing rhodium exhibits the highest ethylene glycol production activity, but this catalyst system cannot avoid rhodium precipitation during the reaction, which makes it expensive. This is a serious drawback in the cyclical use of catalysts. Although various solutions have been proposed, the situation is still unsatisfactory industrially. Various studies have been conducted on catalyst systems based on Group I elements of the periodic table other than rhodium, but these catalyst systems require higher pressures to cause significant reactions, and Usually, the production ratio of ethylene glycol is low. Iridium-based catalysts are one of them, and according to a conventionally known example, 1,000 kg/C
Formation of ethylene glycol has been observed only at pressures above 77°C. That is, W Keim et al. J, Ca
tal, 61, 359 (1980), 2,
000 bar, and in the example described in US Pat. No. 4,170,606, 1,750 kg/CTII. Even under these conditions, the rate and selectivity of ethylene glycol production are still unsatisfactory. As a result of intensive studies to improve the drawbacks existing in the prior art regarding catalysts containing iridium carbonyl compounds, the inventors of the present invention have found that by making an appropriate amount of an organic phosphorus compound exist in the reaction system, the reaction pressure is 1,000 kg/1 or less. They also discovered that the production activity of oxygen-containing lower hydrocarbons such as ethylene glycol and methanol is dramatically increased, leading to the present invention.

That is, the present invention produces ethylene by reacting a mixture of a liquid catalyst, carbon monoxide, and hydrogen (hereinafter referred to as synthesis gas) in the presence of a catalyst consisting of an iridium carbonyl compound and a valent organic phosphorus compound. The present invention provides an industrially useful improved method for efficiently producing oxygen-containing lower hydrocarbons such as glycol and methanol.

Next, a method of implementing the present invention will be explained in detail.

The iridium carbonyl compound used as the main catalyst in the present invention refers to an iridium compound containing one or more carbon monoxide as a ligand.

Included among these are organic iridium compounds containing one or more carbon monoxides as a ligand. These organic iridium compounds contain, in addition to carbon monoxide, one or more atoms or atomic groups that form direct bonds with iridium atoms through atoms such as hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, arsenic, etc. It may be hot. Iridium compounds that can be converted to iridium carbonyl compounds under the reaction conditions can also be used as starting materials for the catalyst.

Examples of suitable iridium carbonyl compounds for use in the process of the invention include dodecacarbonyltetriridium(0), dicarbonyliridium(1) acetylacetonate, bistriphenylphosphineiminium pentadecacarbonyliridium(l), Lidocarbonyltris(triphenylphosphine)iridium (
) etc.

Among these, dodecacarbonyltetriridium is the most commonly used and preferred. In the method of the present invention,
An appropriate amount of an organic phosphorus compound is used as an auxiliary agent with respect to the iridium carbonyl compound as the main catalyst.

These valent organic phosphorus compounds broadly include those having a structure in which atoms of carbon, hydrogen, oxygen, sulfur, halogen, phosphorus, nitrogen, etc. are directly bonded to a phosphorus atom in the molecule. Preferred organic phosphorus compounds in the present invention are phosphine derivatives represented by the general formula PRlR,R.

Here, R, , R, , R represent the same or different substituted or unsubstituted alkyl groups, aryl groups, cycloalkyl groups, or hydrogen atoms. An unsubstituted alkyl group, aryl group, or cycloalkyl group refers to a hydrocarbon group whose skeleton carbon number is within the range of 1 to 24, and a substituent refers to an atom other than hydrogen bonded to the skeleton carbon or any of these atoms. means an atomic group containing an element.

There are no particular restrictions on the type or number of substituents as long as they do not inhibit the reaction, such as alkyl groups, alkoxyl groups, cyano groups,
This is typified by halogen atoms, etc.

Specific examples of these phosphine derivatives include triethylphosphine, tri-1-propylphosphine, tri-n-butylphosphine, triphenylphosphine, tri(p-
methoxyphenyl)phosphine, p-tolyldiphenylphosphine, 4-promophenyldiphenylphosphine, tri(2-cyanoethyl)phosphine, diphenylphosphine, bis(1,4-diphenylphosphine)butane, etc. It is.

Examples of other organic phosphorus compounds include methoxydiphenylphosphine, chlorodiphenylphosphine, phenylphosphine, and the like. In the present invention, the preferred range of the amount of the valent organic phosphorus compound used is from 0.001 to 100, more preferably from 0.01 to 10, expressed as the atomic ratio of phosphorus to iridium.

Iridium carbonyl compounds and valent organophosphorus compounds are
Although both can be separately charged into the reaction system, it is also possible to form an iridium carbonyl compound containing a valent organic phosphorus compound as a ligand in advance and introduce it into the reaction system.

Further, the above catalyst can be supported on a suitable inorganic or organic carrier and subjected to the reaction in a heterogeneous state. Preferably, the method of the present invention uses a suitable liquid catalyst.

Suitable liquid catalysts include, for example, water, alcohols, ethers, carboxylic acids, carboxylic acid anhydrides, esters, lactones, ketones, amides, sulfones,
Mention may be made of sulfoxides, aliphatic or aromatic hydrocarbons and mixtures thereof. Among these, amides, lactones, and sulfones are particularly preferred; for example, N-methylpyrrolidone, γ-butyrolactone, and sulfolane are excellent catalysts. The concentration of the main catalyst iridium carbonyl compound used is from 10-5 to 10 gram atoms, preferably 1 gram atom, as iridium atoms, relative to the liquid medium 11.
It ranges from 0-3 to 1 gram atom.

The molar ratio of carbon monoxide and hydrogen in the raw material synthesis gas is 1:1
A range of 0 to 10:1 is suitable, and it may be diluted with a so-called inert gas such as helium, nitrogen, or methane.

Furthermore, there is no problem even if carbon dioxide is included in the synthesis gas. The reaction pressure is 10 to 3,000 kg/7 ll of Cl, preferably 50 kg/Cl, expressed as the total pressure of synthesis gas.
to 1,0001<g/Crll is suitable.
The reaction temperature is 100 to 400°C, more preferably 150°C.
~350°C, and the reaction time may vary depending on the catalyst used and reaction conditions, but is preferably in the range of 0.1 to 100 hours.
The method of the present invention can be carried out either continuously or batchwise.

Desired products such as ethylene glycol, methanol, etc.
It can be easily separated from the reaction solution by conventionally known separation operations such as distillation and extraction, or a combination thereof.

The catalyst in the residual liquid from which the desired product has been separated can be recycled to the reaction system and reused through various regeneration processes or without special treatment.

Ethylene glycol obtained according to the method of the present invention is a chemical product useful as a raw material for polyester fibers, an antifreeze component, and the like. EXAMPLES The method of the present invention will be specifically explained below with reference to Examples, but the scope of the present invention is not limited thereto.

Example 1 After the inside of a shaking type Hastelloy C autoclave with an internal volume of about 30 rfL1 was sufficiently purged with nitrogen gas, 0.5 milligram atom of dodecacarbonyltetriridium as an iridium atom, 0.5 mmol of triphenylphosphine and Distillation-purified N-methylpyrrolidone 7.5
WL1 was charged and the contents were mixed homogeneously under nitrogen.

The autoclave is closed and the molar ratio of carbon monoxide to hydrogen is 1.
After replacing the inside of the autoclave three times with 1:1 synthesis gas, 600 kg/C! The pressure was increased to IL.

The autoclave was heated and kept at 270° C. for 4 hours while shaking at a rate of 60 times per minute to carry out the reaction. The pressure during reaction is maximum approximately 750 kg/~, final approximately 700 kg
g/Cd. After the reaction was completed, the autoclave was cooled with water to room temperature, and the gas contained therein was gradually released.

The reaction solution was homogeneous, and no precipitates such as iridium metal were observed.

A portion of the liquid reaction product and released gas were collected and quantitatively analyzed using a gas chromatograph.

The results are shown in Table 1. EG, MeOH, HCO, M in the table
e and EtOH do not represent ethylene glycol, methanol, methyl formate and ethanol.

Examples 2 to 12 Reactions and analyzes were carried out in exactly the same manner as in Example 1, except that triphenylphosphine in Example 1 was replaced with another organic phosphorus compound.

The results are shown in Table 1. Comparative Example 1 Reaction and analysis were carried out in exactly the same manner as in Example 1, except that the addition of an organic phosphorus compound was omitted.

The results are shown in Table 1. Examples 3 to 16 Example 1 except that other iridium carbonyl compounds were used in place of dodecacarbonyltetriridium in Example 1 and/or the reaction time was changed.
The reaction and analysis were carried out in exactly the same manner.

The results are shown in Table 2. Comparative Examples 2 and 3 Comparative Example 1 except that another iridium carbonyl compound was used in place of dodecacarbonyltetriridium in Comparative Example 1 and/or the reaction time was changed.
The reaction and analysis were carried out in exactly the same manner.

The results are shown in Table 2.

Examples 17 to 21 Except for changing some of the reaction conditions such as the amount of organic phosphorus compound added, solvent, reaction temperature, and time in Example 1,
The reaction and analysis were carried out in exactly the same manner as in Example 1.

The results are shown in Table 3.

Comparative Examples 4 and 5 Reaction and analysis were carried out in exactly the same manner as in Comparative Example 1, except that some of the reaction conditions such as the solvent, reaction temperature, and time in Example 1 were changed.

The results are shown in Table 3. Examples 22 to 24 Exactly the same as Example 1 except that the amount of triphenylphosphine added in Example 1 was changed. The reaction and analysis were performed using the following method.

The results are shown in Table 4.

Claims (1)

[Claims] 1. A method for producing oxygen-containing lower hydrocarbons, which is characterized by reacting a mixture of carbon monoxide and hydrogen in a liquid medium in the presence of a catalyst consisting of an iridium carbonyl compound and a III-valent organic phosphorus compound. Production method. 2 The III-valent organic phosphorus compound has the general formula PR_1R_2R
A patent characterized in that it is a phosphine derivative represented by _3 (where R_1, R_2, and R_3 represent the same or different substituted or unsubstituted alkyl groups, aryl groups, cycloalkyl groups, or hydrogen atoms) A method according to claim 1.