JPS6124525A - Preparation of mixture of alcohol with hydrocarbon - Google Patents

Abstract

PURPOSE:To obtain a mixture of alcohol and hydrocarbon in good yield from a gas containing hydrogen and carbon monoxide using a relatively inexpsensive catalyst, i.e. a catalyst containing molybdenum and cobalt, as main active ingredients, in a specific ratio supported on a carrier. CONSTITUTION:A gas (a synthetic gas) containing hydrogen and carbon monoxide is contacted with a catalyst prepared by supporting both molybdenum and 0.1-0.5pts.wt. cobalt to 1pt.wt. molybdenum as main active ingredients on a carrier (preferably silica gel) preferably at 230-300 deg.C under of 20-100kg/cm<2>G pressure to obtain the aimed mixture of alcohol and hydrocarbon. Since the above-mentioned catalyst containing no noble metal is inexpensive and has a relatively long catalyst life, the mixture is obtained advantageously. The above- mentioned catalyst has a relatively low sensitivity of catalytic property to temperature change and the alcohol in the reactor is in the gas form, an inexpensive reactor can be used.

Description

[Detailed Description of the Invention] [Object of the Invention and Industrial Field of Application] This invention provides a method for producing a mixture of alcohol and hydrocarbons from a gas containing hydrogen and carbon monoxide (hereinafter simply referred to as synthesis gas). Regarding. In other words, the method of the present invention is a method for producing a mixture of alcohol and hydrocarbon (hereinafter simply referred to as "product") from synthesis gas using a catalyst containing molybdenum and cobalt as the main effective metal components. The aim is to obtain products in good yields using inexpensive catalysts.

[Prior Art] Many studies have been conducted and published regarding catalysts for producing hydrocarbons, alcohols, or a mixture of both from synthesis gas. These conventional catalysts can be summarized as follows. The first type of conventional catalyst is a catalyst containing copper, chromium, zinc, etc. as the main active ingredients, and has already been used on a large scale as a catalyst for methanol production.
Many improvements have been made to produce aliphatic-hydric alcohols (hereinafter referred to as intermediate alcohols) of ~5.

However, this type of catalyst has a poor yield of J intermediate alcohols, and has not been put to practical use as a catalyst for the purpose of producing intermediate alcohols. That is, if an attempt is made to increase the yield of intermediate alcohols, lower hydrocarbons such as methane and carbon dioxide will be produced in an increased amount, and the effective utilization rate of -carbon oxide will decrease. In recent years, in order to eliminate the drawbacks of the first conventional catalyst, a second conventional catalyst containing noble metals such as rhodium, ruthenium, platinum, etc. as the main active ingredient has been announced. This second conventional catalyst can be used in three ways: one is to bring the catalyst into contact with synthesis gas in the gas phase, and the other is to bring the catalyst into contact with the synthesis gas in a liquid phase in a suitable solvent in which the catalyst is dispersed. However, all of these catalysts are extremely expensive and have insufficient performance, so they have not been put into practical use. In addition, two-component catalysts of cobalt and molybdenum have been studied as catalysts for Fischer-Tropsch hydrocarbon synthesis.
This catalyst has a cobalt content higher than a molybdenum content.

[Disclosure of the Invention] The catalyst containing molybdenum and cobalt as main active ingredients used in the method of this invention is a novel catalyst in which the molybdenum content is greater than the cobalt content.

The method of this invention will be explained in detail below, focusing on the catalyst used in the method of this invention. The catalyst used in the process of this invention is a concentrated aqueous solution of various ammonium molybdates, preferably those having an atomic ratio of molybdenum and oxygen in ammonium molybdate of 7=24, and a water-soluble salt of cobalt, preferably cobalt nitrate. The weight of cobalt element is 0.1 part or more and 0.5 part by weight of
The metal salt aqueous solution is impregnated into a dried granular carrier so as to have an aqueous solution of the metal salt, and then the carrier holding the metal salt aqueous solution is dried and then fired. The concentration of the aqueous solution with which the carrier is impregnated is preferably a saturated solution or a concentrated aqueous solution close to saturation between room temperature and 100° C. from the viewpoint of allowing a certain amount of the carrier to carry a large amount of the active ingredient. The carrier holding these impregnated solutions is dried at 100 to 150 ml under normal pressure.
0°C, preferably 0.5-12 at a temperature of 110-130°C
It is best to carry out the test in air for an hour. The firing carried out after this drying is carried out at 350-450°C, preferably at 380-450°C.
It is preferable to carry out the firing in air at a temperature of 420° C., and the firing is usually completed in about 2 hours. As the carrier, silica gel, porous spherical alumina, granular activated carbon, granular carbon, granular diatomaceous earth, etc. can be used, and among these usable carriers, silica gel is a particularly preferred carrier.

In the method for producing the catalyst for the method of the present invention as described above, a carrier is impregnated with a mixed aqueous solution of ammonium molybdate and a baltate whose molybdenum element content and cobalt element content are adjusted to desired values within the above ranges. Drying and firing may be carried out as described above, but the carrier is first impregnated with only an aqueous solution of ammonium molybdate, and then dried, fired, and the fired product is cooled. By impregnating it with the required amount of aqueous salt solution and then drying and firing it a second time? , it is possible to obtain a catalyst with superior performance compared to that obtained by the simultaneous impregnation method of the above-mentioned mixed aqueous solution. No matter which of the above two impregnation methods is used, the material that has been impregnated with the metal component and subsequently dried and fired is impregnated with a concentrated aqueous solution of potassium carbonate, and then dried in the same manner as above. By conducting the process under these conditions, a catalyst with even better performance can be produced. The catalyst prepared above contains a total amount of molybdenum and cobalt as oxides of 10 to 60%, based on the weight of the dry support. Naturally, catalysts with a total content of molybdenum and cobalt oxides of less than 10% by weight, based on the dry support, have insufficient performance.

In the case of a catalyst impregnated with potassium, the amount of potassium supported is preferably 10 to 100% by weight as fused potassium based on the weight of the molybdenum element.

In the catalyst used in the above method of the present invention, the content ratio of cobalt to molybdenum is very important. In other words, if the weight ratio of cobalt to molybdenum is 0.5 or more, even if the same carrier is used and the same manufacturing method as above is used, the amount of product produced will be lower than when this ratio is within the above range. is small. Similar cobalt content ratio 0.
5 or more, the product production amount may show a maximum value, but the product production amount at this maximum value is compared to the case where the cobalt content ratio is in the range of 0.2 to 0.5,
It is small. In addition, if the cobalt content ratio is 0.1 or less,
Similarly, the amount of product produced decreases.

At the above cobalt content ratio of 0.5 or more, the content ratio at which the product production amount reaches its maximum value is a catalyst composition in which molybdenum is added as a co-catalyst to a so-called cobalt catalyst, which has been well known in the past. Conceivable. Regarding the amount of potassium supported, if the amount of supported potassium is less than the above lower limit, the amount of methane produced will increase to some extent, and conversely, if the amount of supported potassium is more than the above upper limit, the amount of methane produced will increase to some extent. It cannot be said that the performance is the best, but it is usable.

In the method of this invention, a product is produced by bringing the catalyst produced above into contact with synthesis gas containing hydrogen and carbon monoxide. As conditions such as temperature and pressure during this contact, conventionally well-known conditions can be used. That is, the temperature ranges from 200 to 350°C, preferably 230 to 300°C, and the pressure ranges from normal pressure to 200°C.
ka/cmG, preferably a range of 20 to 100 kg/cdG can be used. Using a catalyst temperature higher than the above temperature range will increase the production of methane and carbon dioxide, and using a temperature lower than the above temperature range will result in insufficient catalyst activity and a decrease in product production. Either case is disadvantageous. As a reactor for bringing the catalyst and synthesis gas into contact under the above conditions, either a well-known fixed bed reactor or a fluidized bed reactor can be used, but in either case, the Since a large amount of reaction heat is generated, it is desirable to have a catalyst bed structure having a cooling heat transfer surface that is in direct contact with the gas and catalyst during the reaction.

In addition, water or an organic liquid having an appropriate boiling point is used as a coolant in contact with the cooling heat transfer surface on the opposite side of the cooling heat transfer surface from the surface that contacts the catalyst and gas under pressure. It is preferable to use the vapor-liquid wet phase in an upward flow as it is in a boiling state.

When a fluidized bed reactor is used, it is preferable to use, as a carrier, spherical alumina or silica gel, which has a particle size of 0.1 to 0.5 mm and is wear resistant. Furthermore, as mentioned above, the quantitative ratio of catalyst and gas when bringing the catalyst and synthesis gas into contact varies greatly depending on the pressure used during the reaction, but for example, in the case of normal pressure, the amount of catalyst is about 1° Ogr. In contrast, a flow rate of 1 mol of synthesis gas per hour is preferable, but as the reaction pressure is increased, the flow rate of catalytic gas is increased to 1 mol per hour for a catalyst Is amount of about 2 ar. The amount used can be reduced.

In this invention, a mixture of alcohol and hydrocarbon can be produced in good yield by using the above catalyst and the conditions for contacting the catalyst with synthesis gas. The amount of product obtained per mole of synthesis gas varies greatly depending on the reaction conditions, the composition of the synthesis gas, especially the content of hydrogen and carbon monoxide in the synthesis gas, and the molar ratio of hydrogen and carbon monoxide. When the synthesis gas does not contain components other than hydrogen and carbon monoxide, and the molar ratio of hydrogen to carbon monoxide is 1.0, by passing the raw material gas once through the catalyst bed, 2.
It is possible to obtain a product of about 0 to 3.0 or. As mentioned above, the product obtained by the method of this invention is a mixture of alcohol and hydrocarbon. The alcohol in this mixture contains a small amount of methanol, but is mainly composed of the above-mentioned intermediate alcohol, and the hydrocarbons include small amounts of methane and ethane. It is a mixture mainly consisting of aliphatic saturated hydrocarbons having 3 to 6 carbon atoms, including lower hydrocarbons such as. The weight ratio of alcohol to hydrocarbon in the product produced by the method of this invention varies depending on the type of carrier used in the catalyst, the ratio of molybdenum to cobalt, the amount of potassium supported, etc. It varies between 65%. Therefore, the optimal value of the molar ratio of hydrogen to carbon monoxide in the synthesis gas varies depending on the component composition of the product, which changes with changes in the composition of the catalyst, but the preferred value for this molar ratio is 2. .5～
A range of 3.5 can be mentioned. If the molar ratio of hydrogen and carbon monoxide in the raw material gas is close to the optimal value selected from the above range and the content of inert gas components other than hydrogen and carbon monoxide is small, synthesis The residual gas that has not been converted into a product after one contact between the gas and the catalyst is mixed into the raw material gas to produce synthesis gas, and the residual gas is brought into repeated contact with the catalyst to improve the product yield per mole of raw gas. I can force it. Also, in this invention method,
The product obtained under the above reaction conditions can be produced by using a mixture of alcohols using well-known means such as conventional rectification or extractive distillation in which rectification is carried out while adding water, either alone or in combination. It is possible to separate a mixture of hydrocarbons, and further to separate the separated alcohol mixture and hydrocarbon mixture into desired components or fractions.

[Effects of the Invention] The first advantage of this invention is that the catalyst is inexpensive. The fact that the catalyst is inexpensive is obvious from the fact that no noble metals are used in the raw materials used to manufacture the catalyst, as described above, and since no particular explanation is required, the explanation will be omitted.

The second advantage of this invention is that the sensitivity of the catalyst performance to temperature changes is relatively small, and as mentioned above, it can be applied over a relatively wide temperature range without causing a large change in catalyst performance. Since the product can be manufactured and there is no need to maintain the temperature of the catalyst bed within ±3° C. as in conventional Fischer-Tropsch catalysts, an inexpensive reactor with a relatively simple structure can be used.

In addition, the content of alloy components other than carbon steel and iron is reduced to 5% by weight by using high-temperature liquid alcohol, which has been well known in the past.
Since the alcohol in the reactor is in a gaseous state, the corrosion of the low alloy steel described below is extremely low, and the above-mentioned inexpensive materials can be used as constituent materials of the reactor.

A third advantage of this invention is that the catalyst has a relatively long life. In other words, the catalyst used in the method of this invention can be used at higher temperatures than conventional catalysts, but this means that the deterioration of catalyst performance due to the so-called sintering phenomenon is small, and the durability of this catalyst is It shows that the sex is good.

Also, although it can be used at high temperatures, this high temperature is at most 35
Since the temperature is about 0°C, the loss of supported potassium due to evaporation is extremely small, and the performance of the catalyst can be maintained well for a long period of time.

Example 1 Ammonium molybdate ((NH4)e MO702
4.4H20) 65.7Or dissolved in 400xl (D water and cobalt nitrate (CO(NO3)2 ・6H
20) Mix a solution of 35.3 Or dissolved in 200 g of water, add 100 g of ID silica gel manufactured by Fuji Dagoson Co., Ltd. to this mixed solution, and heat it to about 95 ° C. on a water bath. The silica gel was impregnated with ammonium molybdate and cobalt nitrate by evaporation to dryness until the moisture disappeared. The solid content obtained by this operation was dried in air at a humidity of 120°C for 12 hours, and then the temperature was raised to 400°C and calcined for about 2 hours to convert molybdenum and cobalt into silica gel in the form of oxides. carried it. Next, the above baked product was added to an aqueous solution in which 7.6g of potassium carbonate was dissolved, and evaporated to dryness on a water bath in the same manner as above to further impregnate potassium carbonate. A catalyst was obtained by drying for about 12 hours.

The content of molybdenum and cobalt in this catalyst is 25.0 and 5.0% by weight as molybdenum and cobalt, respectively. This catalyst is classified using a Tyler sieve, and those that pass through 20 meshes and do not pass through 40 meshes5. 'Oar is taken and filled in a designated place in a stainless steel vertical flow reaction tube (inner diameter 8n length 500+nm), heated to 400°C and passed hydrogen gas for 15 hours to reduce it, and then from the top of the reaction tube. A pressure of 50 ka/CI that does not substantially contain gases other than carbon monoxide and hydrogen and has a molar ratio of carbon monoxide and hydrogen of 1? G synthesis gas at a temperature of 2
0.1 mol of catalyst was passed per hour per ar of catalyst at 50°C, and the generated gas flowing out from the reaction tube was analyzed, and the following results were obtained.

Feed - Reaction rate of carbon oxide mol% 20.1 Mol% of converted light of reacted carbon monoxide Total for alcohols 38.0 Total for hydrocarbons 25. to carbon oxide 37.9 Composition of alcohols produced (wt%) Methanol 23.6 Ethanol 48.3 n-propyl alcohol 17.2 n-butyl alcohol 7.0 Secondary amyl alcohol 5.0 Example 2 Implementation Same amounts of ammonium molybdate solution and cobalt nitrate solution as used in Example 1 were prepared separately, and 100 g of the same silica gel as in Example 1 was first added to the ammonium molybdate solution. , evaporated to dryness at 95°C on a water bath, followed by 12
After drying in air at 0°C for 12 hours,
℃ for 2 hours, and after cooling the fired product, it was added to a cobalt nitrate solution and similarly evaporated to dryness, dried and fired, and then the solid material supported with molybdenum and cobalt was , into the same ω of potassium carbonate solution similar to that used in Example 1.
A catalyst was obtained by drying in the same manner as in the case of . The molybdenum, cobalt and potassium contents of this catalyst are similar to those obtained in Example 1. This catalyst was classified in the same manner as in Example 1, and 5o
r was collected, a test was conducted in the same manner as in Example 1, and the generated gas was analyzed to obtain the following results.

Feed - Reaction rate of carbon oxide mol % 30.9 mol % of converted light of reacted carbon monoxide Total to alcohols 41.1 Total to hydrocarbons 20.6 to carbon dioxide
38.3 Composition of alcohols produced (wt%) Methanol 15.5 Ethanol
50.90-propyl alcohol
21.1 N-Butyl Alcohol 8.4 Amyl Alcohol 4.1 Applicant Toyo Engineering Co., Ltd. Hiroshi Tominaga

Claims (1)

[Claims] On the carrier, molybdenum and 0 parts by weight of molybdenum are added.
．． 1. A method for producing a mixture of alcohol and hydrocarbon, characterized in that a catalyst carrying 1 or more and 0.5 parts by weight or less of cobalt as a main active ingredient is brought into contact with a gas containing hydrogen and carbon monoxide.