JPS6210486B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] 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 carrier, (c) A catalyst comprising rhodium, manganese, iridium and/or lithium supported on a support, and (d) Palladium, iron and/or molybdenum supported. The present invention relates to a process for producing ethanol, which comprises reacting carbon monoxide and hydrogen in the presence of a supported catalyst. [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, manufacturing prices have risen significantly, creating the need to switch raw materials. 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
Nos. 14706, 56-8333, and 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. 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 inventors of the present invention found that, as mentioned above, a rhodium catalyst or a rhodium-manganese catalyst known as a catalyst for producing acetaldehyde and acetic acid was combined with iron and/or molybdenum. The present invention was completed by discovering that ethanol can be produced with high selectivity by combining it with a palladium-containing catalyst. [Summary of the Invention] 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
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 may be mixed or used by filling the catalysts (a) to (c) in the upper layer and the catalyst in (d) in the lower layer. be able to. In preparing the catalyst, a catalyst in which the above-mentioned components are dispersed on a carrier 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 by taking the impregnation method as an example. The above metal compound is dissolved in a solvent such as water, methanol, ethanol, tetrahydrofuran, dioxane, n-hexane, benzene, toluene, etc., a carrier is added to the solution and immersed, and the solvent is distilled off.
It is dried and, if necessary, subjected to treatment such as heating to support the metal compound on the carrier. Supporting methods include preparing a mixed solution in which the raw material compounds are dissolved simultaneously in the same solvent and supporting them on the carrier at the same time, supporting each component on the carrier sequentially, or reducing and heat-treating each component as necessary. It is possible to use various techniques such as a method of sequentially or stepwise loading while performing processing such as the following. 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 performed at the temperature at which rhodium is reduced, that is, about 100°C, but preferably the reduction treatment is performed 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 case of 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 and palladium to the carrier is
Considering the specific surface area of the carrier, the weight ratio is 0.0001~
0.5, preferably 0.001-0.3. Also, (a) ~ (c)
In the catalyst, the ratio of cocatalyst metal to rhodium is 0.001 to 10, preferably 0.01 to 10, respectively in atomic ratio.
The range is 5. Furthermore, (d) in the catalyst, the ratio of iron and molybdenum to palladium is each atomic ratio
It ranges from 0.001 to 10, preferably from 0.01 to 5. 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 to be adopted in carrying out the present invention are:
It is selected by organically combining various reaction condition factors with the aim of producing an oxygen-containing compound containing ethanol as a main component with high yield and high selectivity.
Although the target compound can be produced with high selectivity and high yield even at normal pressure (ie, 0 kg/cm ² gauge), 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. 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, space velocity (raw material gas feed amount x catalyst volume)
is 10h ^-1 in standard conditions (0℃, 1 atm)
It is appropriately selected from the range of 10 ⁶ h ^-1 depending on 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 5 (volume ratio). The present invention will be explained in more detail below using examples. Example 1 Rhodium chloride (RhCl _{3.3H 2} O) 0.480g (1.82
mmol) in an ethanol solution in advance.
3.7 g (10 ml) of silica gel (Davison #57, manufactured by Davison), calcined and degassed under high vacuum at 300°C for 2 hours.
was added and soaked. Next, ethanol was distilled off using a rotary evaporator to dryness, followed by further vacuum drying. After that, the Pyrex reaction tube was filled with a mixed gas of hydrogen and nitrogen (H ₂ :60
ml/min, _N2 : 60 ml/min), activation treatment was performed at 400° C. for 4 hours to prepare a Rh/SiO ₂ catalyst. Next, 0.162 g of palladium chloride (PdCl ₂ ),
_3.7 g of calcined and degassed silica _gel (10
ml) was added and soaked. A Pd-Fe/ _SiO2 catalyst was prepared using the same preparation method and activation treatment as above. The Rh/SiO ₂ catalyst (catalyst 7 ml) and Pd-Fe/SiO ₂ catalyst (3 ml) thus obtained were filled into a reaction tube (made of titanium) of a high-pressure flow reactor so that they formed the upper and lower layers. , under normal pressure hydrogen gas flow (200
ml/min), after re-reduction treatment at 300℃ for about 2 hours,
A mixed gas of carbon monoxide and hydrogen was introduced to carry out the reaction under predetermined reaction conditions. Analysis of reaction products is
The liquid products were dissolved in water and collected, and the gaseous products were collected directly and subjected to gas chromatography analysis, qualitative and quantitative analysis, and the distribution of the products was determined. The results are shown in Table 1. Example 2 Rhodium chloride 0.480g, lithium chloride (LiCl・
Add 300 ml of ethanol solution containing 0.022 g of H ₂ O)
A Rh-Li/SiO ₂ catalyst was prepared by the same treatment as in Example 1 after being immersed in 10 ml of degassed silica gel calcined at °C. Rh-Li/SiO ₂ catalyst (7 ml), Example 1
The Pd-Fe/SiO ₂ catalyst (3 ml) prepared above 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 3 An ethanol solution in which 0.480 g of rhodium chloride and 0.361 g of manganese chloride (MnCl ₂ .4H ₂ O) were dissolved was immersed in 10 ml of degassed silica calcined at 300°C.
On the other hand, an aqueous solution in which 0.162 g of palladium chloride and 0.075 g of molybdenum chloride (MoCl ₅ ) were dissolved was immersed in 10 ml of degassed silica calcined at 300°C. Rh-Mn/SiO ₂ , Pd-Mo/
_SiO2 was prepared. Ph-Mn/SiO ₂ catalyst (6ml)
A reaction tube of a high-pressure flow reactor was filled with Pd-Mo/SiO ₂ (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. Example 4 Rhodium chloride 0.480g, manganese chloride 0.012g,
An ethanol solution containing 0.033g of lithium chloride, 0.177g of palladium chloride, and 0.109g of ferrous chloride.
Rh-Mn-Li/SiO ₂ and Pd-Fe/SiO ₂ catalysts were prepared by the same treatment as in Example 1 after immersing each aqueous solution in which G was dissolved in 10 ml of degassed silica gel calcined at 300°C. Rh-Mn-Li/ _SiO2 catalyst (6
ml) and Pd-Fe/SiO ₂ (2 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 5 Palladium chloride 0.089g, molybdenum chloride 0.035
The aqueous solution in which g was dissolved was immersed in 10 ml of silica gel that had been calcined at 300°C and degassed. Pd-Mo/SiO ₂ was prepared by the same treatment as in Example 1. Rh-Mn-Li/SiO ₂ catalyst (6 ml) prepared in Example 4 and the above Pd-
Mo/SiO ₂ catalyst (2 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, manganese chloride 0.036g,
An ethanol solution containing 0.128 g of iridium chloride (IrCl ₄ H ₂ O) and 0.177 g of palladium chloride.
g, ferrous chloride 0.109g, molybdenum chloride 0.05g
After each aqueous solution was immersed in 10 ml of silica gel which had been calcined and degassed at 300°C, Rh-Mn-Ir/SiO ₂ , Pd-Fe-Mo/
_SiO2 was prepared. Rh-Mn-Ir/ _SiO2 catalyst (6
ml) and Pd-Fe-Mo/SiO ₂ catalyst (2 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 7 Rhodium chloride 0.480g, manganese chloride 0.018g,
An ethanol solution containing 0.064g of iridium chloride and 0.022g of lithium chloride, and palladium chloride.
Rh-Mn
-Ir-Li/ _SiO2 and Pd-Fe/ _SiO2 were prepared. Rh
-Mn-Ir-Li/SiO ₂ catalyst (7 ml) and Pd-Fe/
A reaction tube of a high-pressure flow reactor was filled with SiO ₂ catalyst (3 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/SiO ₂ catalyst (10 ml) prepared in Example 1 was filled into a reaction tube of a high-pressure flow reactor.
The activity test was conducted in the same manner as above. The results are shown in Table 1. Comparative Example 2 Rh-Li/SiO ₂ catalyst prepared in Example 2 (10
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 3 The Rh-Mn-Li/SiO ₂ catalyst (10 ml) prepared in Example 4 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. 【table】

Claims (1)

[Scope of Claims] 1. Ethanol comprising reacting carbon monoxide and hydrogen in the presence of a catalyst comprising rhodium supported on a carrier and a catalyst comprising palladium, iron and/or molybdenum supported on a support. How to manufacture. 2 Production of ethanol by 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 palladium, iron and/or molybdenum supported on a support. how to. 3 consisting of 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 palladium, iron and/or molybdenum supported on a support, A method of producing ethanol.