JPS6353168B2 - - Google Patents

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 and copper supported on a carrier, (rho) a catalyst comprising rhodium, copper and lithium or manganese supported on a support, and (c) rhodium, copper, manganese, iridium and/or lithium. This invention relates to a method for producing ethanol, which comprises reacting carbon monoxide and hydrogen in the presence of any of the catalysts supported on a carrier and (iv) a catalyst consisting of copper, 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, considering the rapid price fluctuations and supply instability of crude oil in recent years, and the limited amount of crude oil resources, there is a need to develop alternative carbon resources. On the other hand, various methods of producing an oxygen-containing compound having 2 carbon atoms from a mixed gas of carbon monoxide and hydrogen, which is available in abundance and at low cost, have been studied. That is, by reacting a mixed gas of carbon monoxide and hydrogen in the presence of a catalyst containing rhodium as a main component and consisting of a metal or metal oxide such as manganese, titanium, zirconium, or tungsten, an oxygen-containing compound having two carbon atoms is produced. Methods for selectively producing 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. It was hot.
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. 1989-1999
No. 14706, No. 56-8333, No. 56-8334) have been proposed, but all of these methods mainly produce acetaldehyde and acetic acid, and the yield of ethanol and
It has the disadvantage of extremely low selectivity. Recently, a method for selectively synthesizing ethanol by combining the above-mentioned rhodium-based catalyst known as a catalyst for producing acetaldehyde and acetic acid with a catalyst containing iron and/or molybdenum and rhodium, palladium, iridium, etc. Showa 61-
178935, JP-A-61-191633, JP-A-61-
191634, JP-A-61-191635), the selectivity of ethanol is not a satisfactory result for a practical process. In addition, an alcohol synthesis process from synthesis gas using a five-component catalyst containing copper, rhodium, alkali metals, etc. is known (USP4537909), but the ethanol selectivity is low and the by-product ratio of methanol and propanol is high. . 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. When producing an oxygen-containing compound from a gas containing carbon monoxide and hydrogen, the present inventors have improved the selection of the above-mentioned oxygen-containing compound having 2 carbon atoms and This paper discloses a catalyst system that makes it possible to shift the distribution of oxygen-containing compounds to ethanol and minimize the production of hydrocarbons, and has conducted intensive studies on combination tests of numerous co-catalyst components. As a result, by combining any of the catalysts (a), (b), and (c) above with a catalyst consisting of copper, zinc, and/or chromium, an unexpected effect appears, and ethanol has a preferable yield. The present inventors have discovered that it can be obtained with high selectivity and have completed the present invention. [Means for Solving the Problems] As described above, the present invention involves reacting carbon monoxide and hydrogen in the presence of any one of the catalysts (a) to (c) and the catalyst (d) to produce ethanol. It is manufactured. The present invention will be explained in detail below. As mentioned above, the catalyst used in the present invention is
Two catalysts consisting of one of the catalysts (a) to (c) and the catalyst (d) are the main constituents. Both catalysts must be prepared separately, and when used, they should be mixed or used by filling the catalysts (a) to (c) in the upper layer and the catalyst in (d) in the lower layer. I can do it. In the preparation of the catalyst, a catalyst in which the above-mentioned components are dispersed on a support is usually used, 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, and carbonates; organic salts such as acetates, oxalates, acetylacetonate salts, dimethylglyoxime salts, and ethylenediamine acetate; Compounds commonly used in preparing noble metal catalysts can be used, such as 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 using the impregnation method as an example. The above metal compound is dissolved in a solvent such as water, methanol, ethanol, tetrahydrofuran, dioxane, hexane, benzene, toluene, etc., a carrier is added and immersed in the solution, the solvent is distilled off, and the mixture is dried.
If necessary, treatment such as heating 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, the two catalysts are prepared separately using these methods. Other preparation methods, such as a method in which metals are supported by ion exchange using the ion exchange ability of a carrier, and a method in which a catalyst is prepared by a coprecipitation method, are also adopted as methods for preparing the catalyst used in the method of the present invention. can. The catalyst prepared by the above-mentioned method is usually activated by reduction treatment and then subjected to reaction. It is convenient and preferable to carry out the reduction using a hydrogen-containing gas at an elevated temperature. At this time, the reduction treatment can be carried out at the temperature at which rhodium is reduced, that is, about 100°C, but preferably the reduction treatment is carried out at a temperature of 200°C to 600°C. At this time, hydrogen reduction may be carried out while raising the temperature gradually or stepwise 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 borohydride compound, or an aluminum hydride compound. The carrier used in the present invention preferably has a specific surface area of 10 to 1000 m ² /g and a pore diameter of 10 Å or more, which is commonly known as a carrier. As a specific carrier,
Examples include silica-based carriers such as silica, silicates, silica gel, molecular sieves, and diatomaceous earth, alumina, and activated carbon, with silica-based carriers being preferred. In any of the catalysts (a) to (c), 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 0.001 to 0.3 by weight, taking into account the specific surface area of the carrier. Further, in the catalysts (a) to (c), the ratio of the promoter metal to rhodium is in the range of 0.0001 to 10, preferably 0.005 to 3, respectively, in terms of atomic ratio. Furthermore, in the catalyst (d), the ratio of zinc and chromium to copper is each in the range of 0.01 to 50, preferably 0.1 to 10, in terms of atomic ratio. (d) The catalyst is prepared by coprecipitation method or carrier loading 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.
Further, the catalysts (a) to (c) and the catalyst (d) may be packed in the same reaction tube or may be packed in separate reaction tubes and combined. 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 adopted in carrying out the present invention are selected by organically combining various reaction condition factors with the aim of producing oxygen-containing compounds containing ethanol as the main component with high yield and high selectivity. be done. The reaction pressure is normal pressure (i.e. 0Kg/cm ² gauge)
However, the target compound can be produced with high selectivity and high yield, but the reaction can be carried out under pressure in order to increase the space-time yield. Therefore, the reaction pressure is 0Kg/cm ² gauge ~ 350
Kg/cm ² gauge, preferably 0Kg/cm ² gauge ~ 250
Perform under pressure of Kg/cm ² gauge. Reaction temperature is 150℃
-450°C, preferably 180°C - 350°C. Although the reaction temperature may be the same for catalysts (a) to (c) and (d), it is preferable to set them to different reaction temperatures in order to obtain high ethanol selectivity and production activity. 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:
10 h ^-1 to 10 ⁶ h ^-1 in standard conditions (0°C, 1 atm)
It is selected as appropriate from the range of the relationship between the reaction pressure, reaction temperature, and raw material gas composition. The composition of the raw material gas is mainly a gas containing carbon monoxide and hydrogen, and inert gases such as nitrogen, argon, helium, and methane, or hydrocarbons and carbonic acid if they are in a gaseous state under the reaction conditions. It may contain gas or water. The mixing ratio of carbon monoxide and hydrogen is CO/ _H2 ratio of 0.1 to 10, preferably 0.2 to 4 (volume ratio). The present invention will be explained in more detail below using Examples. It should be noted that among the reaction products, it was recognized that carbon dioxide gas decreased significantly over time, so the amount of carbon dioxide gas produced was excluded when calculating the product selectivity. Example 1 Rhodium chloride (RhC1 _{3.3H 2} O) 0.480g
(1.82mmol), cupric chloride (CuCl ₂ 2H ₂ O) 0.006
3.7 g of silica gel (Davison #57, manufactured by Davison), which had been previously calcined and degassed under high vacuum at 300°C for 2 hours in an ethanol solution in which 0.037 mmol of silica gel was dissolved
(10 ml) was added and immersed. Next, ethanol was distilled off using a rotary evaporator to dryness, followed by further vacuum drying. After that, it was filled into a Pyrex reaction tube and heated at 450 mL under atmospheric pressure with a mixed gas of hydrogen and nitrogen (H ₂ : 20 ml/min, N ₂ : 20 ml/min).
Activation treatment was performed at ℃ for 4 hours to prepare a Rh-Cu/SiO ₂ catalyst. Next, copper nitrate (Cu(NO ₃ ) ₂ .
3H ₃ O) 0.895g, zinc nitrate (Zn(NO ₃ ) ₂・6H ₂ O)
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 silica gel was dissolved. After drying in the same manner as above, it was fired in air at 350°C for 3 hours. Then, under atmospheric pressure and aeration with a mixed gas of hydrogen and nitrogen (H ₂ : 2 ml/min, N ₂ : 50 ml/min),
After activation treatment at 350℃ for 3 hours, Cu-Zu/SiO ₂
A catalyst was prepared. Rh obtained in this way
Cu/SiO ₂ catalyst (catalyst 2 ml) and Cu-Zn/SiO ₂ catalyst (0.5 ml) were filled into the reaction tube (made of titanium) of a high-pressure flow reactor so as to form the upper and lower layers, and the mixture was heated with atmospheric hydrogen gas. After re-reduction treatment at 200° C. for about 2 hours under flow (200 ml/min), a mixed gas of carbon monoxide and hydrogen was introduced to carry out the reaction under predetermined reaction conditions. For analysis of reaction products, liquid products are dissolved in water and collected, gaseous products are directly collected, gas chromatography is performed, qualitative and quantitative analysis is carried out,
The product distribution was determined. The results are shown in Table 1. Example 2 An ethanol solution containing 0.480 g of rhodium chloride, 0.006 g of cupric chloride, and 0.022 g of lithium chloride (LiCl・H ₂ O), 1.763 g of copper nitrate, and chromium nitrate (Cr(NO ₃ )・9H ₂ O) ) 10ml of silica gel in which 2.189g of ethanol solution was calcined at 300℃ and degassed.
After immersing each solution in the solution, Rh-Cu-Li/SiO ₂ and Cu-Cr/SiO ₂ catalysts were prepared in the same manner as in Example 1. Rh-Cu-Li/SiO ₂ catalyst (2ml),
A reaction tube of a high-pressure flow reactor was filled with Cu-Cr/SiO ₂ catalyst (0.5 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. Example 3 Silica 10 was prepared by baking and degassing an ethanol solution containing 0.480 g of rhodium chloride, 0.006 g of cupric chloride, and 0.018 g of manganese chloride (MnCl ₂ 4H ₂ O) at 300°C.
immersed in ml. On the other hand, copper nitrate 1.763g, zinc nitrate
An aqueous solution in which 1.085 g was dissolved was immersed in 10 ml of degassed silica calcined at 300°C. Rh-Cu-Mn/SiO ₂ , Cu-Zu/
_SiO2 was prepared. Rn-Cu-Mn/SiO ₂ catalyst (2
ml) and Cu-Zu/SiO ₂ (3 ml) were 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. Example 4 An ethanol solution containing 0.480 g of rhodium chloride, 0.006 g of cupric chloride, 0.011 g of manganese chloride, and 0.033 g of lithium chloride was immersed in 10 ml of silica gel that had been calcined at 300°C and degassed. Through the treatment, Rh-Cu-Mn-Li/SiO ₂ catalyst was prepared. Rh--Cu--Mn--Li/SiO ₂ catalyst (2 ml) and Cu--Zu/SiO ₂ catalyst (3 ml) prepared in Example 3 were filled into the upper and lower layers of the reaction tube of a high-pressure flow reactor. The reaction temperature of Cu-Mn-Li catalyst is 265℃,
The reaction temperature of the Cu--Zu catalyst was set at 275°C, and an activity test was conducted in the same manner as in Example 1. Table 1 shows the results.
It was shown to. Example 5 Rh-Cu-Mn-Li/SiO ₂ prepared in Example 4
Catalyst (2 ml) and Cn-Zn/ prepared in Example 2
SiO ₂ catalyst (3 ml) was 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 6 Rhodium chloride 0.480g, cupric chloride 0.006g, manganese chloride 0.011g, iridium chloride ( _IrCl4 .
An ethanol solution in which 0.064 g of H ₂ O) and 0.033 g of lithium chloride were dissolved was immersed in 10 ml of silica gel that had been calcined at 300°C and degassed. On the other hand, 10 ml of silica was immersed in an aqueous solution in which 1.763 g of copper nitrate, 1.085 g of zinc nitrate, and 1.460 g of chromium nitrate were dissolved. Rh-Cu-Mn-Ir-Li/SiO ₂ , Cu-
A Zn-Cr- _SiO2 catalyst was prepared. Rh―Cu―Mn―
Ir-Li/SiO ₂ catalyst (2 ml) and Cu-Zn-Cr/SiO ₂
The catalyst (3 ml) was 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. Comparative Example 1 Rh-Cu/SiO ₂ catalyst prepared in Example 1 (2
ml) was filled 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. Comparative Example 2 The Rh-Cu-Li/SiO ₂ catalyst (2 ml) prepared in Example 2 was filled into a reaction tube of a high-pressure flow reactor.
An activity test was conducted in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 3 Rh-Cu-Mn-Li/SiO ₂ prepared in Example 4
A reaction tube of a high-pressure flow reactor was filled with the catalyst (2 ml), and an activity test was conducted in the same manner as in Example 1. The results are shown in Table 1. 【table】

Claims (1)

[Claims] 1. A catalyst comprising rhodium and copper supported on a carrier;
A process for the production of ethanol, comprising reacting carbon monoxide and hydrogen in the presence of a catalyst consisting of 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, copper and lithium or manganese supported on a carrier, and a catalyst comprising copper, zinc and/or chromium. 3 Rhodium, copper, manganese, iridium and/or
Or a method for producing ethanol, which comprises reacting carbon monoxide and hydrogen in the presence of a catalyst comprising lithium supported on a carrier and a catalyst comprising copper, zinc and/or chromium.