JPS63415B2 - - 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, scandium, iridium and/or lithium supported on a carrier;
(b) It relates to a method for producing ethanol by reacting carbon monoxide and hydrogen in the presence of a catalyst comprising (1) rhenium or (2) rhenium and zinc supported on a carrier. [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 rise in crude oil prices in recent years, manufacturing prices have risen significantly.
The need for raw material conversion is emerging. 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 is abundant and available at low cost, have been studied. That is, a mixed gas of carbon monoxide and hydrogen, with rhodium as the main component, manganese, titanium, zircon,
A method for selectively producing an oxygen-containing compound having 2 carbon atoms by reacting it in the presence of a catalyst made of a metal such as iron or a metal oxide is known (for example, Japanese Patent Application Laid-open No.
−80806, No. 52-14706, No. 56-147730, etc.)
It is. However, this method produces a large amount of by-product hydrocarbons, such as methane, and the amount produced is extremely low when the selectivity of oxygen-containing compounds is low or when the selectivity of oxygen-containing compounds is high. It was hot. Furthermore, the actual situation is that the amount of target compounds produced per 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, rhodium, lithium (Japanese Patent Application Laid-Open No. 56-8334), and iron (Japanese Patent Application Laid-Open No. 51-80807) were used to produce oxygen-containing compounds having two carbon atoms in high yield and with high selectivity.
However, all of these methods mainly produce acetaldehyde, acetic acid, or methanol, and the yield and selectivity of ethanol are extremely low. Has low drawbacks. 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. The present inventors have proposed that when producing an oxygen-containing compound from a gas containing carbon monoxide and hydrogen, while improving the selectivity of the above-mentioned oxygen-containing compound having two carbon atoms, The present invention discloses a catalyst system that makes it possible to shift the distribution of oxygenated compounds into ethanol and minimize the production of hydrocarbons. As a result, by combining (a) a catalyst containing rhodium, scandium, iridium and/or lithium on a carrier, and (b) a catalyst containing (1) rhenium or (2) rhenium and zinc on a carrier, Unexpected effects were expressed, and the inventors discovered that ethanol has a preferable yield and high selectivity, leading to the completion of the present invention. [Summary of the Invention] As described above, the present invention comprises (a) a catalyst comprising rhodium, scandium, iridium and/or lithium supported on a carrier, and (b) (1) rhenium or (2) rhenium and zinc supported on a support. In the presence of a catalyst formed by
Ethanol is produced by reacting carbon monoxide and hydrogen. The present invention will be explained in detail below. As mentioned above, the catalyst used in the present invention includes (a) a catalyst comprising rhodium, scandium, iridium and/or lithium supported on a carrier, and (b) a catalyst comprising rhenium (1) or (2) rhenium and zinc supported on a support. The main constituents are two catalysts consisting of: Both catalysts can be prepared separately, and when used, they are mixed or used by filling one of the catalysts in (a) in the upper layer and one in the catalyst in (b) in the lower layer. be able to. In preparing the catalyst (a), the above-mentioned components are usually dispersed on a carrier as is done for noble metal catalysts. The catalyst (a) used in the method of the present invention can be prepared according to the conventional method used when using noble metals. For example, it can be prepared by an impregnation method, a dipping method, an ion exchange method, a coprecipitation method, a kneading method, etc. Raw materials for rhodium and iridium, which are components of the catalyst, include halides such as chloride and bromide, inorganic salts such as nitrate and carbonate, acetate, oxalate, and acetylacetate. Compounds commonly used in preparing noble metal catalysts can be used, such as organic acid salts or chelate compounds such as nato salts and ethylenediamine acetate, carbonyl compounds, ammine complexes, metal alkoxide compounds, and alkyl metal compounds. Raw material compounds that can be used for scandium and lithium used as promoters include halides, inorganic acid salts such as halogenates, nitrates, and carbonates, and organic acids such as hydroxides, formates, acetates, and oxalates. Salt etc. can be used. As raw material compounds that can be used as rhenium, perrhenates, halides, acetates, acetylacetone carbonyl compounds, and the like can be used. Further, as raw material compounds that can be used as zinc, halides, nitrates, acetates, metal alkoxide compounds, etc. can be used. In order to facilitate the loading of these catalyst components onto a support, compounds highly soluble in ethanol, water or other suitable solvents are preferably used. 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 single or mixed solvent such as water, methanol, ethanol, acetone, tetrahydrofuran, dioxane, n-hexane, benzene, toluene, etc., a carrier is added to the solution, immersed, the solvent is distilled off, and the mixture is dried. If necessary, heating, gas treatment, etc. are performed to support the metal compound on the carrier. (a) or (b) The method for supporting the catalyst is to prepare a mixed solution in which the raw material compounds are dissolved in the same solvent and support them simultaneously on the carrier, to support each component sequentially, or to support each component as needed. Refund according to
Various methods can be used, such as a method of supporting the material sequentially or stepwise while performing treatments such as heat treatment. Other preparation methods, such as a method of supporting a metal by ion exchange using the ion exchange ability of a carrier, a method of preparing a catalyst by a coprecipitation method, a method of kneading, etc., can also be used for the catalyst used in the method of the present invention. It can be adopted as a preparation method. The catalysts (a) and (b) prepared by the above-mentioned method are 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. As the reduction temperature of the catalyst in (a), as the reduction temperature of rhodium, the temperature at which rhodium is reduced, i.e. 100
Although the reduction treatment can be performed at a temperature of about 0.degree. C., the reduction treatment is preferably performed at a temperature of 200.degree. C. to 600.degree. 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. Further, the catalyst (b) can be subjected to reduction treatment in the same manner as the catalyst (a). 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. Specific carriers include silica, various silicates, alumina, activated carbon,
Examples include oxides of various metals (for example, zirconium oxide, titanium oxide, magnesia, etc.), molecular sieves, diatomaceous earth, etc., but silica-based carriers are preferred. The ratio of each component in the catalyst (a) above is as follows. The ratio of rhodium to carrier is preferably 0.0001 to 0.5 by weight considering the specific surface area of the carrier.
It is 0.001-0.3. The ratio of scandium and rhodium is scandium/rhodium (atomic ratio) 0.0001
-10, preferably 0.005-3. The ratio of iridium to rhodium (iridium/rhodium (atomic ratio)) is in the range of 0.001 to 6, preferably 0.005 to 3. The ratio of lithium to rhodium (lithium/rhodium (atomic ratio)) is in the range of 0.001 to 3, preferably 0.001 to 2. Further, the ratio of each component in the catalyst (b) above is as follows. Re
The weight ratio of and to the carrier is from 0.001 to 50, preferably from 0.01 to 10, taking into consideration the specific surface area of the carrier. The ratio of zinc to rhenium (zinc/rhenium (atomic ratio)) is in the range of 0.01 to 30, preferably 0.1 to 10. The present invention can be applied, for example, to a fixed bed flow reactor. That is, the above (b) in the reactor
One of the catalysts in (a) is packed on top of one of the catalysts in (a), or one of the catalysts in (a) and one of the catalysts in (b) are mixed and packed. Then, raw material gas is introduced to carry out the reaction. It is also possible to separate the product and recycle and reuse the unreacted raw material gas after purifying it if necessary. The present invention can also be applied to a fluidized bed type reactor. That is, the reaction can also be carried out by mixing the raw material gas with one of the catalysts (a) and (b) and allowing a fluidized catalyst to accompany the mixture.
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 when carrying out the method of the present invention are various reaction conditions for the purpose of producing oxygen-containing compounds whose main component is ethanol in high yield and high selectivity while minimizing the production of hydrocarbons. are selected by organically combining these factors. The reaction pressure is normal pressure (i.e. 0 Kg/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 0 kg/cm ² gauge to 350 kg/cm ² gauge, preferably 0 kg/cm ² gauge to 250 kg/cm ² gauge. The reaction temperature is 150°C to 450°C, preferably 180°C to 350°C. When the reaction temperature is high, it is necessary to increase the feed rate of raw materials or change the composition ratio of hydrogen and carbon monoxide because the amount of hydrocarbon by-product increases. Therefore, the space velocity (feeding amount of raw material gas/catalyst capacity) is in the range of 10 h ^-1 to 10 ⁷ h ^-1 in standard conditions (0°C, 1 atm), so the reaction pressure,
It is selected as appropriate based on the relationship with the reaction temperature and raw material gas composition. The composition of the raw material gas is a gas mainly containing carbon monoxide and hydrogen, and gases such as nitrogen, argon, helium, methane, etc., or hydrocarbons and dioxide if in a gaseous state under the reaction conditions. It may contain carbon, generated oxygen-containing compounds, and water. The mixing ratio of hydrogen and carbon monoxide is hydrogen/carbon monoxide (volume ratio) of 0.1 to 10, preferably 0.25 to 5, and the total proportion of carbon monoxide and hydrogen in the raw material gas is 20 to 100% by volume. Preferably 60~
It is 100% by volume. The present invention will be explained in more detail with reference to Examples below, but these Examples are purposely shown under the same reaction conditions in order to facilitate understanding of the present invention.
It goes without saying that the present invention is not limited in any way by this. Example 1 1.20 g of rhodium chloride (RhCl _{3.3H 2} O), 0.059 g of scandium chloride (ScCl 3.6H ₂ O), and 0.055 _g of lithium chloride (LiCl.H ₂ O) in 11.5 ml of methanol.
silica gel (DAVISON
After adding 25ml of GR-91112), at room temperature and under reduced pressure.
Dry for 15 hours. This supported catalyst was packed into a Pyrex glass reaction tube, and hydrogen was heated at 40 ml/min under 450 ml of hydrogen.
Rh-Sc-Li catalyst was prepared by reduction at ℃ for 5 hours. Also ammonium perrhenate (NH ₄ ReO ₄ ) 1.10
g was dissolved in 22.5 ml of water, 15 ml of silica gel (FUJI-DAVISON #57) was added thereto, and the mixture was heated and dried under reduced pressure. Reduction treatment was carried out in the same manner as above, except that the reduction temperature was 400°C. A Re catalyst was prepared. Activity test and results A titanium reaction tube with an inner diameter of 18 mm and a thermocouple protection tube with an outer diameter of 8 mm was filled with 15 ml of the above Re catalyst, and then 10 ml of the above Rh-Sc-Li catalyst was diluted with 30 ml of the above silica gel. and filled it. The inside of the reaction tube was replaced with nitrogen, and after being re-reduced at 200℃ for 1 hour with nitrogen-diluted hydrogen gas ( _H2 : _N2 = 200:200ml/min) under normal pressure, hydrogen/carbon monoxide = 2/1. A mixed gas of (volume ratio) of 210 N1/hour was fed, and the reaction was carried out at a reaction pressure of 20 Kg/cm ² and a reaction temperature of 275°C. Of the reaction effluent, the liquid product was absorbed and collected in water, and the effluent gas composition was analyzed by gas chromatography, and the results are shown in Table 1. Example 2 In the same manner as in Example 1, Rh-
A Sc-Li catalyst was prepared. Also, 1.10 g of ammonium perrhenate, 3.50 g of zinc nitrate (Zn(NO ₃ ) ₂・6H ₂ O)
g was dissolved in 30 ml of water, 15 ml of the silica gel described above was added thereto, dried under heating and reduced pressure, and reduced in the same manner as in Example 1 to prepare a Re-Zn catalyst. The same reactor as in Example 1 was filled with 15 ml of the above Re-Zn catalyst, and then the above Rh-Sc-Li catalyst was charged.
After diluting and filling 10 ml with 30 ml of the silica gel described above, the reaction was carried out in the same manner as in Example 1.
The results are shown in Table 1. Example 3 Rhodium chloride 1.20g, scandium chloride 0.059
g, 0.055 g of lithium chloride, and 0.064 g of iridium chloride (IrCl ₄ H ₂ O) were dissolved in 11.5 ml of methanol, and after adding 25 ml of the silica gel described in Example 1, the same procedure as in Example 1 was carried out. A Rh-Sc-Li-Ir catalyst was prepared by drying and reduction treatment. In addition, 15 ml of the above Re catalyst was charged into the same reaction apparatus as in Example 1, and then the above Rh-Sc-Li-Ir
After 10 ml of the catalyst was diluted with 30 ml of the silica gel described above and filled, the reaction was carried out in the same manner as in Example 1. The results are shown in Table 1. Example 4 In the same manner as in Example 3, Rh-
A Sc-Li-Ir catalyst was prepared. Also, in the same manner as in Example 2, with the same composition ratio.
A Re-Zn catalyst was prepared. The same reactor as in Example 1 was charged with 15 ml of the above Re-Zn catalyst, and then the above Rh-Sc-Li-Ir
After 10 ml of the catalyst was diluted with 30 ml of the silica gel described above and filled, the reaction was carried out in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 1 Rh-Sc was prepared in the same manner as in Example 1 with the same composition ratio.
Example 1 except that -Li catalyst was prepared and 10 ml of it was diluted with 30 ml of silica gel as described above and packed.
The reaction was carried out in the same manner. The results are shown in Table 1. Comparative Example 2 Rh-Sc was prepared in the same manner as in Example 3 with the same composition ratio.
The reaction was carried out in the same manner as in Example 1, except that -Li-Ir catalyst was prepared and 10 ml of it was diluted with 30 ml of the silica gel described above and charged. The results are shown in Table 1. 【table】

Claims (1)

[Claims] 1. A catalyst comprising rhodium, scandium, iridium and/or lithium supported on a carrier, (1)
A method for producing ethanol, which comprises reacting carbon monoxide and hydrogen in the presence of rhenium or (2) a catalyst comprising rhenium and zinc supported on a carrier.