JPS6259227A - Production of ethanol - Google Patents

Abstract

PURPOSE:To selectively obtain the aimed compound, by using a catalyst of a specific rhodium based catalyst and a copper catalyst containing zinc and/or chromium in combination in producing ethanol from carbon monoxide and hydrogen. CONSTITUTION:Carbon monoxide is reacted with hydrogen in the presence of any of a catalyst containing rhodium supported on a carrier, (B) a catalyst containing rhodium and lithium or manganese supported on a carrier or (C) a catalyst containing rhodium and manganese, iridium and/or lithium supported on a carrier and (D) a catalyst consisting of copper, zinc and/or chromium to selectively give ethanol. The weight ratio of the rhodium to the carrier in the catalysts (A)-(C) is preferably 0.001-0.3 and the atomic ratio of the cocatalyst to the rhodium in the catalysts (B) and (C) is preferably respectively 0.01-5. The atomic ratios of the zinc and chromium to the copper in the catalyst (D) are preferably 1-10 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing ethanol. More specifically, (a) a catalyst comprising rhodium supported on a carrier, (b) a catalyst comprising rhodium and lithium or manganese supported on a support, and (c) a catalyst comprising rhodium, manganese, iridium and/or lithium supported on a support. Any of the catalysts and (d) copper,
The present invention relates to a process for producing ethanol, which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst consisting of zinc and/or chromium.

[Prior art and problems to be solved by the invention] Oxygen-containing compounds having two carbon atoms, such as ethanol and acetaldehyde, have conventionally been produced by a petrochemical method using naphtha as a raw material. However, due to the recent rise in the price of crude oil, the manufacturing price has increased significantly, making it necessary to switch raw materials.

On the other hand, various methods for producing oxygen-containing compounds having 2 carbon atoms from a mixed gas of carbon monoxide and hydrogen, which are abundant and available at low cost, have been studied. In other words, a mixed gas of carbon monoxide and hydrogen is reacted with rhodium as the main component in the presence of a catalyst made of a metal or metal oxide such as manganese, titanium, zirconium, or tungsten to form an oxygen-containing gas containing 2 carbon atoms. Methods for selectively producing compounds are known.

However, this method also produces a large amount of by-product hydrocarbons such as methane, and when the selectivity of oxygen-containing compounds is low or the selectivity of oxygen-containing compounds is high, the selectivity of the main product is low. Ta. The reality is that the amount of the target compound produced based on rhodium, which is an expensive noble metal, is still small, and a technology that has been completed economically and process-wise has not been provided.

Furthermore, a catalyst in which manganese is added to rhodium and an improved method thereof (Japanese Patent Application Laid-open No. 14706.56-8
No. 333.56-8334) has been proposed, but both methods use acetaldehyde and acetic acid as main products, and have the disadvantage that the yield and selectivity of ethanol are extremely low.

As described above, no method has been provided for efficiently and economically producing an oxygen-containing compound containing ethanol as a main component from a gas containing carbon monoxide and hydrogen.

As a result of intensive studies on a method for selectively producing ethanol, the present inventors found that, as mentioned above, a rhodium-based catalyst and a copper catalyst containing zinc and/or chromium, which are known as catalysts for producing acetaldehyde and acetic acid, were used. The present invention was completed by discovering that ethanol can be produced with high selectivity by combining the following.

[Means for solving problems]

As described above, the present invention produces ethanol by reacting carbon monoxide and hydrogen in the presence of any one of the catalysts (a) to (c) and the catalyst (d).

The present invention will be explained in detail below.

As mentioned above, the catalyst used in the present invention is (a) to
It is necessary to use separately prepared catalysts for both catalysts whose main constituents are either one of the catalysts in (c) and the catalyst in (d). It can be used as a mixture or by filling the catalysts (a) to (c) in the upper layer and the catalyst (d) in the lower layer. In preparing the catalyst, a catalyst is usually used in which the above-mentioned components are dispersed on a carrier, as is done for noble metal catalysts.

The catalyst used in the present invention can be prepared using conventional noble metal methods. For example, it can be prepared by an impregnation method, a dipping method, an ion exchange method, a coprecipitation method, a kneading method, etc.

The raw material compounds for the various components constituting the catalyst include inorganic salts such as oxides, chlorides, nitrates, carbonates, acetates, oxalates, acetylacetonate salts, dimethylglyoxime salts, ethylenediamine acetate, etc. Compounds commonly used in preparing noble metal catalysts can be used, such as organic salts or chelates, carbonyl compounds, cyclopentadienyl compounds, ammine complexes, metal alkoxide compounds, and alkyl metal compounds.

The method for preparing the catalyst will be explained below by taking the impregnation method as an example.

The above metal compound is dissolved in a solvent such as water, methanol, ethanol, tetrahydrofuran, dioxane, hexanebenzene, toluene, etc., and a carrier is added and immersed in the solution.
The solvent is distilled off and dried, and if necessary, heating or other treatment is performed to support the metal compound on the carrier.

Supporting methods include preparing a mixed solution in which the raw material compounds are simultaneously dissolved in the same solvent and supporting them on the carrier at the same time, supporting each component on the carrier sequentially, or reducing each component as necessary. Various methods can be used, such as a method of supporting the material sequentially or stepwise while performing treatments such as heat treatment. Incidentally, as described above, each of the three catalysts is prepared separately using these methods.

Other preparation methods, such as a method in which a metal is supported by ion exchange utilizing the ion exchange ability of a carrier and a method in which a catalyst is prepared by a coprecipitation method, can also be employed as a method for preparing the catalyst used in the method of the present invention.

The catalyst prepared by the above method is usually activated by reduction treatment and then subjected to reaction. In order to carry out the reduction, it is convenient and preferable to carry out the reduction using a hydrogen-containing gas at an elevated temperature. In this case, the reduction temperature can be the temperature at which rhodium is reduced, that is, about 100°C, but preferably 200°C to 6°C.
The reduction treatment is carried out at a temperature of 00°C. At this time, hydrogen reduction may be performed while the temperature is gradually or stepwise raised from a low temperature in order to sufficiently disperse each component of the catalyst. Further, reduction can also be carried out chemically using a reducing agent. For example, reduction treatment may be performed using carbon monoxide and water, or using a reducing agent such as hydrazine, a boron hydride compound, or an aluminum hydride compound.

The carrier used in the present invention preferably has a specific surface area of 1
Any carrier commonly known as a carrier can be used as long as it has a pore size of 0 to 1000 rrr/g and a pore diameter of 10 mm or more. Specific carriers include silica-based carriers such as silica, silicates, silica gel, molecular sieves, and diatomaceous materials, alumina, and activated carbon, with silica-based carriers being preferred. In any of the catalysts (a) to (d), the concentration and composition ratio of each component in the catalyst can be varied within a wide range.

The ratio of rhodium to the carrier is 0.0001 to 0.5, preferably 0.0 in terms of weight per liter, considering the specific surface area of the carrier.
01 to 0.3. Further, in the catalysts (a) to (c), the ratio of the cocatalyst metal to rhodium is in the range of 0.001 to 10, preferably 0.01 to 5, respectively, in terms of atomic ratio. Furthermore, in the catalyst (d), the ratio of zinc and chromium to copper is each in an atomic ratio of 0.1 to 50, preferably 1 to 50.
The range is 10. (d) The catalyst is prepared by a coprecipitation method or a support method.

The present invention can be applied to, for example, a fixed bed flow reactor. That is, a reactor is filled with a catalyst, and a raw material gas is introduced to cause a reaction.

It is also possible to separate the product and purify the unreacted raw material gas, which can then be recycled and reused.

Further, the present invention can also be applied to a fluidized bed type reactor. That is, the reaction can also be carried out by bringing the raw material gas and the fluidized catalyst together. Furthermore, the present invention can also be applied to a liquid phase heterogeneous reaction in which a catalyst is dispersed in a solvent and a raw material gas is introduced to carry out the reaction.

The conditions employed in carrying out the present invention are such that the target compound can be produced with high selectivity and high yield, and the reaction can be carried out under pressure in order to increase the space-time yield.

Therefore, the reaction pressure is Qkg/cd gauge ~ 350k
It is carried out under a pressure of g/ctA gauge, preferably Okg/ct gauge to 250 kg/cJ gauge. The reaction temperature is 150°C to 450°C, preferably 180°C to 350°C.
It is ℃. When the reaction temperature is high, the amount of hydrocarbon by-product increases, so it is necessary to increase the feed rate of the raw material.

Therefore, the space velocity (raw material gas feed rate x catalyst volume) is 101, -1 to 10 bh in terms of standard conditions (0°C, 1 atm).
-' is appropriately selected based on the relationship between the reaction pressure, reaction temperature, and raw material gas composition.

The composition of the raw material gas is a gas mainly containing carbon monoxide and hydrogen, and nitrogen, argon, helium,
It may contain an inert gas such as methane, or a hydrocarbon, carbon dioxide gas, or water as long as it is in a gaseous state under the reaction conditions. The mixing ratio of carbon monoxide and hydrogen is CO/H, a ratio of 0
．． 1 to 10, preferably 0.2 to 5 (volume ratio).

The present invention will be explained in more detail below with reference to Examples.

Ethanol solution 1- in which (1,82mmo I) was dissolved
3.7 g (10 ml) of silica gel (Davison #57, manufactured by Davison), which had been previously calcined and degassed under high vacuum at 300° C. for 2 hours, was added and immersed. Next, ethanol was distilled off using a rotary evaporator to dryness, followed by further vacuum drying. After that, the Pyrex reaction tube is filled with a mixed gas of hydrogen and nitrogen (Hz:
60m1/min, Nz: 400℃ under ventilation of 60m1/min
Activation treatment was performed for 4 hours to prepare a Rh/SiOz catalyst. Next, copper nitrate (Cu (NOx>z・
3HwO) 1.895g, zinc nitrate (Zn (NOz)
3.7 g (10 ml) of calcined and degassed silica gel was added and immersed in an aqueous solution in which 1.085 g of Z.z.6Hio) was dissolved. Cu using the same preparation method and activation treatment as above.
-Zn/SiO□ catalyst was prepared. The Rh/S i O thus obtained was used as a catalyst (catalyst 8 ml),
Cu -Z n /5IO2 catalyst (2 ml) was packed into a reaction tube (made of titanium) of a high-pressure flow reactor so as to form an upper layer and a lower layer, and the mixture was heated under normal pressure hydrogen gas flow (200 m 1
After re-reduction treatment at 300° C. for about 2 hours, qualitative and quantitative monoxide analysis was performed to determine the distribution of the product. Yumu (
Rh
A L l/S l0il Cu Cr/S l0il2 catalyst was prepared. Rh Li/Si0g (catalyst 2ml
), Cu-Cr/Sin, and a catalyst (0.5 ml) were filled in the upper and lower layers of a reaction tube of a high-pressure flow reactor, and an activity test was conducted in the same manner as in Example 1.

The results are shown in Table 1.

Example 3 Rhodium chloride 0.480g, manganese chloride (MnC1,
-4) Rh Mn/S 10i, Cu-Z n/S by dissolving 0.018 g (to)
i O! was prepared. Rh-Mn/5108 catalyst (2
ml) and Cu Z n /S i O as a catalyst (2 m
1) was filled into the upper and lower layers of a reaction tube of a high-pressure flow reactor, and an activity test was conducted in the same manner as in Example 1. The results are shown in Table 1.

After immersing in Example 4, Rh-M was treated in the same manner as in Example 1.
An n-Li/S ioz catalyst was prepared.

Rh-Mn-Li/SiO□ catalyst (2 ml), Example 2
The CCu-Cr-3in catalyst (2 ml) prepared in Example 1 was filled in the -L layer and the lower layer in a reaction tube of a high-pressure flow reactor, and an activity test was conducted in the same manner as in Example 1. The results are shown in Table 1.

Example 5 0.480 g of rhodium chloride and 0.011 g of manganese chloride were used. On the other hand, copper nitrate 1.895g, zinc nitrate 2.333g
An aqueous solution in which 0.730 g of chromium nitrate was dissolved was added to silica 1
It was immersed in 0ml. By the same treatment as in Example 1, Rh
-Mn-1r-Lt/5iOz, Cu-Zn-Cr/S
An i0g catalyst was prepared. Rh-Mn-1r-Li/Si
0g catalyst (2ml) and Cu-Zn-Cr/Si
The reaction tube of a high-pressure flow reactor was filled with O and the catalyst (2 ml) in the upper and lower layers, and an activity test was conducted in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 The Rh/Si0g catalyst (10 m+) prepared in Example 1 was packed into a reaction tube of a high-pressure flow reactor, and an activity test was conducted in the same manner as in Example 1. The results are shown in Table 1.

Table 1 shows the results of an activity test conducted in the same manner as in Example 1.

A reaction tube of a high-pressure flow reactor was filled with the catalyst (Q'm I), and an activity test was conducted in the same manner as in Example 1.

The results are shown in Table 1.

Made of rigid conspiracy H juice ＜　Dimensions Place = Yo -

Claims (3)

[Claims] (1) A method for producing ethanol, which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst comprising rhodium supported on a carrier and a catalyst comprising copper, zinc and/or chromium. (2) A method for producing ethanol, which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst comprising rhodium and lithium or manganese supported on a carrier and a catalyst comprising copper, zinc and/or chromium. (3) Ethanol is produced by reacting carbon monoxide and hydrogen in the presence of a catalyst comprising rhodium, manganese, iridium and/or lithium supported on a carrier, and a catalyst comprising copper, zinc and/or chromium. Manufacturing method.