JPH0460154B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a process for obtaining high yields of hydrocarbons, in particular hydrocarbons in the gasoline boiling range, from synthesis gas, a mixture of hydrogen and gaseous carbon oxides such as carbon monoxide and/or carbon dioxide. More specifically, when producing hydrocarbons by bringing a composite catalyst of a metal or/and metal oxide and crystalline zeolite having catalytic activity for hydrogenating carbon monoxide into contact with synthesis gas, the reaction is carried out in a suspended bed. The present invention relates to a method in which hydrorefined heavy cycle oil from a catalytic cracking process is used as a liquid medium. Hydrocarbons in the gasoline boiling range, including motor gasoline and other light gases, are produced industrially by distillation of crude oil or by known processes such as catalytic reforming of naphtha, catalytic cracking of heavy fractions, and hydrocracking. Manufactured. However, due to the need to cope with the future rise in crude oil prices and the scarcity of crude oil supply sources, there is a need to produce hydrocarbons in the gasoline boiling point range from carbon resources other than petroleum, for which demand is expected to grow in the future.
Attempts are being made to develop so-called new fuel oil production technology. Until now, the energy development field has been exploring technologies to convert carbon resources other than crude oil into hydrocarbons equivalent to petroleum. For example, methods such as direct liquefaction of coal and cracking of tar sand oil or oil sand oil are being studied. It has been. However, these methods require extremely high pressure, are complicated, and are not economically effective because the quality of the products obtained is inferior to that of petroleum. On the other hand, it is already commercially possible to convert carbon sources such as coal and natural gas into gas mixtures consisting of hydrogen and gaseous carbon oxides such as carbon monoxide and/or carbon dioxide in the presence of air, oxygen or water vapor. Established. Furthermore, from the mixed gas, the reaction temperature is 150 to 500.
It is also possible to produce hydrocarbons using a catalyst mainly composed of group elements at a temperature of 1000 atm or less at a reaction pressure of 1000 atm or less. For example, the most widely studied process, the Fitschier-Tropschew process, has already been adopted by South African SASOL as a process for producing light gas, gasoline and other hydrocarbon oils from syngas, and various hydrocarbons have been produced from coal on a commercial scale. ing. However, in the Fischer-Tropsch process, the product is mainly composed of straight-chain paraffinic hydrocarbons, so the research process octane number of the gasoline fraction is as low as about 50, making it unsuitable as a current automobile fuel. In addition, the product has a wide range of hydrocarbon carbon numbers ranging from 1 to 30, and has the disadvantage of poor selectivity for hydrocarbons in the gasoline boiling point range. On the other hand, it is well known that synthesis gas can be converted into oxygen-containing organic compounds such as methanol using metals such as copper, zinc, and chromium or metal oxide catalysts. It is also known that hydrocarbons in the gasoline boiling range can be selectively converted by contacting them under conditions of , 50 atm or less. The crystalline zeolite for this purpose is ZSM-5
10064, JP-A-52-8005), ZSM-48
There are a series of ZSM series high silica crystalline aluminosilicate, mordenite zeolite etc. Recently, an efficient method for producing gasoline boiling range hydrocarbons directly from synthesis gas has been identified. This method uses a composite catalyst of a metal or metal oxide and crystalline zeolite having an activity to hydrogenate carbon monoxide, such as a Fischer-Tropsch catalyst or a methanol synthesis catalyst, to convert synthesis gas into
Hydrocarbons are produced in stages. One specific method uses a catalyst that mechanically mixes a metal oxide with the activity of hydrogenating carbon monoxide and crystalline zeolite, and the other method uses a catalyst with the activity of hydrogenating carbon monoxide. This is a catalyst prepared by supporting a metal having the following properties on a crystalline zeolite or a composite of the crystalline zeolite and another metal oxide having the activity of hydrogenating carbon monoxide. The method for producing hydrocarbons from synthesis gas in one step using the composite catalyst shown above is still in the development stage, and all of the reactions are carried out using a solid bed reactor, but there are still some problems in processing. catalyst life,
Problems such as catalyst activity/selectivity and control of catalyst layer reaction temperature remain to be solved. In particular, the reaction heat of the reaction to produce hydrocarbons and alcohols from synthesis gas is quite large as shown in Table 1, and in these synthesis reactions, the removal of this reaction heat is an important factor in selecting a reactor. That's a problem. Table 1 Heat of reaction per carbon ΔH Kcal CH ₄ −50 C ₂ H ₆ −42 C ₆ H ₁₄ −39 C ₂ H ₄ −26 C ₆ H ₁₂ −34 CH ₃ OH −23.9 C ₂ H ₅ OH − 29.5 The methanol synthesis reaction that is already being carried out industrially is carried out in a fixed bed, which is possible because the conversion rate of carbon monoxide is low and a large amount of gas is recycled to remove the reaction heat. . However, as in the reaction of the present invention, when a high carbon monoxide conversion rate is required and the reaction intermediate is methanol, the final hydrocarbon product is produced through a dehydration reaction, which is an even more exothermic reaction. Therefore, when it comes to practical use, it is extremely difficult to use a fixed bed reactor in terms of removing the reaction heat. Although it is not the reaction of the present invention, a gas-phase fluidized bed reactor or suspended bed reactor is ideal for the large exothermic reaction of the similar reaction process known as the Fischier-Tropsch process, due to the ease of heat removal. A variety of studies have been carried out, and gas-phase fluidized beds have been industrialized by SASOL in South Africa. Here, the gas phase fluidized bed refers to a reaction method in which a powder catalyst of 10 to 100 μm forms a fluidized state in a reactor with a reaction gas fluid rising from below at elevated temperature and pressure. Suspended bed reaction is a method in which a powder catalyst of 100 μm or less is suspended and dispersed in a liquid medium consisting of high-boiling paraffinic hydrocarbon oil, and the reaction is carried out by catalyzing the slurry of the catalyst and a reaction gas fluid in an upward flow. means. Gas-phase fluidized beds are preferable for reaction heat removal, but the wear resistance of the catalyst is a problem due to repeated collisions between catalysts in a violently fluidized state, and it cannot be applied to precipitated iron-based Fitscher-Tropschule catalysts, which have weak strength. It is said that On the other hand, in a suspended bed, the catalyst particle size is preferably finer, so it is possible to use a weaker catalyst, and the reaction heat is removed more easily than in a gas-phase fluidized bed.
It's even easier. Usually, to carry out the Fischer-Tropsch reaction in a suspended bed, precipitated iron-based iron oxide powder of 5 μm or less is dispersed in paraffin-based mineral oil with a boiling point of 300° C. or higher, and a slurry concentration of 5 to 30 wt% is used. Based on the knowledge of the Fitschier-Tropsch process, it is natural to try to solve the problem of reaction heat removal by performing the reaction for producing hydrocarbons from synthesis gas, which is handled in the present invention, in a gas-phase fluidized bed or suspended bed. In particular, when dealing with a catalyst system in which the main component of the catalyst is crystalline zeolite, which consists of fine particles and has relatively low strength, it is highly analogous that the suspended bed is the most preferable reaction method. It would be natural. The paraffinic suspension used in the Fitscher-Tropsch process has a similar composition to the high-boiling fraction of hydrocarbon oil produced from synthesis gas in the Fitscher-Tropsch reaction, so it can be extracted as a slurry, separated and recovered, and recycled again. It is recyclable and does not undergo any decomposition or other conversion to light fractions under the reaction conditions, so there is no loss. For this reason, paraffinic hydrocarbons are preferred liquid media in the Fischer-Tropsch reaction. However, since paraffinic hydrocarbons are easily decomposed in the presence of crystalline zeolite, the paraffinic hydrocarbons used in the Fischer-Tropsch method cannot be used as they are in the reaction carried out in the present invention. For this reason, no attempt has been made to perform a one-stage reaction to produce hydrocarbons from synthesis gas in a suspended bed using a composite catalyst of a Fischer-Tropsch synthesis catalyst or a methanol synthesis catalyst and crystalline zeolite. However, as a result of extensive research, the present inventors discovered a specific liquid medium that enabled them to produce hydrocarbons from synthesis gas using a suspended bed method even in a system using crystalline zeolite as a catalyst component. The present invention has been completed based on the discovery that the method of the present invention can be carried out, and that the method of the present invention has favorable effects on extending the life of the catalyst and improving the yield of hydrocarbons in the gasoline boiling point range. That is, the present invention brings hydrocarbons, particularly hydrocarbons in the gasoline boiling point range, into high yield by contacting synthesis gas with a composite catalyst made of metals and/or metal oxides having an activity for hydrogenating carbon monoxide and crystalline zeolite. The method involves a suspended bed reaction method in which the catalyst is dispersed in a specific liquid medium and used as a slurry, in which a heavy cycle oil fraction, which is a by-product from the catalytic cracking process of heavy gas oil, is used as the liquid medium. with a boiling point of 250℃ or higher and an aromatic content of 50wt% obtained by hydrodesulfurization and preferably catalytic dewaxing treatment.
The present invention relates to a method for directly producing hydrocarbons from synthesis gas using a mixture of the above heavy aromatic hydrocarbons (naphthenic hydrocarbons and paraffinic hydrocarbons having a residual alkyl group). Since the liquid catalyst is a heavy aromatic mixture, the liquid medium is not decomposed into light fractions in the synthesis gas conversion reaction, and in the reaction of the present invention, the shape of the crystalline zeolite present as a catalyst component is Selectivity is exhibited, and the boiling point is reduced from synthesis gas.
Substantially no hydrocarbons are produced above 200°C, and for these two reasons, hydrocarbons produced from synthesis gas can be easily separated from the liquid medium due to the difference in boiling point. In addition, replenishment of the liquid medium during long periods of the reaction,
Since there is no need to perform extraction, the process is simplified and becomes an economical process. In the present invention carried out in a suspended bed reactor, the heat of reaction can be easily removed, thereby avoiding hot spots and temperature runaway in parts of the catalyst layer that are often experienced in fixed beds. It can be operated at a uniform temperature. For this reason, the methane reaction, which tends to proceed at high temperatures, and the secondary decomposition of generated hydrocarbons in the gasoline boiling point range can be suppressed to a lower level than in fixed bed reactors, making it possible to obtain hydrocarbons in the gasoline boiling point range in high yields. can. In addition, in fixed bed reactions, coke usually adheres to the catalyst surface during the reaction, reducing activity and shortening the catalyst life. However, in the present invention, since the liquid medium is a heavy aromatic, coke is a precursor to coke. Since the catalyst is dissolved and removed by a liquid medium in the body, there is almost no coke adhesion, which can cause a decrease in catalyst activity, and the catalyst has the surprising effect of maintaining stable activity over a long period of time. Next, the present invention will be explained in more detail. Synthesis gas, which is a reaction raw material, is not particularly limited, and it is usually sufficient as long as the H ₂ /CO molar ratio is 0.5 or more.
Catalyst slurry and 200-450℃, preferably 250-350℃
Temperature in °C, below 100Kg/ ^cm2 , preferably 10-50
Kg/ ^cm2 pressure, 100~10000h ^-1 , preferably 500~
Contact at GHSV condition of 2000h ^-1 . At this time, the gas fluid consisting of light hydrocarbons and inorganic gas separated by the high-pressure separator can be recycled to the reactor inlet. The recycled gas ratio is 0.1 to 100, preferably 0.5 to 10, by volume relative to the raw material synthesis gas. The catalyst is a composite catalyst consisting of a metal or/and metal oxide with catalytic activity to hydrogenate carbon monoxide and crystalline zeolite.
or a composite catalyst of one or more metals or metal oxides such as Cu, Zn, Cr, Pd, etc. and crystalline zeolite to promote the methanol synthesis reaction. It is a composite catalyst. Here, the content of the metal having catalytic activity for hydrogenating carbon monoxide in the catalyst is 0.1 to 15 wt% as metal in the case of a supported catalyst, and 5 to 50 wt% as metal oxide in the case of an oxide catalyst. Crystalline zeolite is usually a three-dimensional network structure in which silica and alumina share oxygen, and the ratio of oxygen atoms to the total of aluminum and silicon atoms is 2, and the negative electricity of these SiO ₂ tetrahedra is Refers to crystalline aluminosilicates balanced with alkali metal cations, especially sodium, potassium or, in some cases, organic nitrogen cations. In addition, some or all of the aluminum may be mixed with other metals, such as iron (Japanese Patent Application Laid-Open No.
76199), chromium (Japanese Unexamined Patent Publication No. 115783), vanadium (West German Patent No. 2831631), bismuth (Japanese Unexamined Patent Application No. 1983-115783),
-196718), Lantern (JP-A-57-10684, JP-A-Sho
58-194737), cerium (JP 57-10684, JP 58-194737), boron (JP 53-55500, JP 55-76825), titanium (JP 57-10684), etc. It also includes crystalline silicates synthesized by substitution with trivalent metals. Generally, crystalline zeolites exist in large numbers in nature, but they can also be produced synthetically, and either of these can be used. In addition, crystalline zeolite has a specific uniform pore diameter due to the way oxygen atoms are bonded due to its crystal structure, and examples of small-pore zeolite with a pore diameter of approximately 5 Å include erionite, offretite,
Ferrierite is a large pore size zeolite with a pore size of about 9 Å, and phosiasite type X or Y zeolite or mordenite is used as a large pore size zeolite with a pore size of about 5 Å.
As a medium pore size zeolite of ~9 Å, ZSM-5
(Special Publication No. 46-10064) and the silica to alumina ratio
12 or more ZSM-11 (Special Publication No. 53-23280), ZSM-12
(Special Publication 16079), ZSM-21 (Special Publication 1977-16079)
54598), ZSM-35 (U.S. Patent Application No. 528061, 1974)
(November 29, 2013), ZSM-38 (U.S. Patent Application No. 528060,
In addition to the ZSM series zeolite developed by Mopil Oil (November 29, 1974), iron silicate developed by Ciel International Research (Japanese Patent Application Laid-Open No. 53-76199), and even though the manufacturing method is different. ZSM-5 type high silica crystalline zeolite whose X-ray diffraction pattern is similar to ZSM-5, and zeolite in which part or all of the alumina of the above zeolite is replaced with other trivalent metals, such as boron silicate ( Japanese Unexamined Patent Publication 1973-
55500), bismuth silicate (JP-A-57-
Tantalum silicate and cerium silicate
194737), etc. In a reaction using a catalyst composite of small-pore zeolite with a pore diameter of about 5 Å, the hydrocarbons produced are linear paraffins or olefins with a molecular size of about 5 Å or less, or carbon atoms with a molecular size of about 5 Å or less, due to the shape selectivity of the zeolite. 5 or less, and in this case, lower olefins such as ethylene, propylene, and butylene, which are useful as petrochemical raw materials, can be obtained. If necessary, these lower olefins can be easily converted to hydrocarbons within the gasoline boiling point range by known methods such as alkylation, disproportionation, dimerization, etc. A catalyst composite of medium pore size zeolite with a pore size of 5 to 9 Å is the most preferred zeolite for obtaining high yields of hydrocarbons in the gasoline boiling range. When trying to obtain mainly aromatic hydrocarbons from hydrocarbons,
In addition to silica sources, alumina sources, and alkali sources, tetrapropylammonium salts (Mobil Oil's ZSM-5 specified in Japanese Patent Publication No. 46-10064, as well as Japanese Patent Application Laid-open No. 51-1982) are used as organic reagents in addition to silica sources, alumina sources, and alkali sources during zeolite synthesis.
-67298, etc.), organic amines (JP-A-50-54598, JP-A-54-99799, etc.), alcohol amines (JP-A-54-107499, etc.), diglycolamines (JP-A-54-107499, etc.), The silica-to-alumina ratio obtained by performing a hydrothermal synthesis reaction in the presence of any of the following:
100 crystalline aluminosilicate can be preferably used. In addition, when mainly obtaining olefin hydrocarbons from hydrocarbons, it is preferable to use crystalline transition metal silicate, which is synthesized by adding a trivalent metal source and does not substantially contain aluminum, in place of the alumina source mentioned above. can. A catalyst made of a composite of large-pore zeolite with a pore diameter of about 9 Å generates not only hydrocarbons below the boiling point range of gasoline, but also kerosene and gas oil fractions, so select this option if you need to co-produce these. be done. In order to use any crystalline zeolite in the conversion reaction of the present invention, it is preferable that at least 50% or more of the cations are exchanged with hydrogen ions, rare earth ions, etc., and acidic points are discovered. Next, the liquid medium essential for preparing the catalyst slurry used in the present invention will be explained. That is, the heavy aromatic hydrocarbon oil used here is obtained by hydrodesulfurizing heavy cycle oil produced as a by-product in a catalytic cracking unit known as a gasoline manufacturing process in an oil refinery. More preferably, it is obtained by subsequent catalytic dewaxing. The catalytic cracking process usually produces straight-run heavy gas oil with a boiling point of 250 to 400℃ obtained by distilling crude oil at atmospheric pressure, or straight-run heavy gas oil with a boiling point of 350℃ obtained by vacuum distillation of heavy oil.
Using vacuum gas oil at ~550°C or desulfurized oil obtained by reducing the sulfur and nitrogen content in a hydrodesulfurization equipment as feedstock, it is processed into zeolite and silica at a temperature of 450-550°C and a pressure of 10 Kg/cm ² G or less. This is a process to obtain a gasoline base material with a high octane number by contacting it in a fluidized state with a powder catalyst made of one or more of alumina and alumina. Under the above conditions, the raw oil is 60~
80vol% undergoes decomposition and is separated into dry gas, LPG and a fraction with a boiling point above naphtha. Subsequently, the fraction above the naphtha boiling point is processed in a distillation column into naphtha with a boiling point of about 200°C or less, light cycle oil (LCO) with a boiling point of about 200 to 300°C, heavy cycle oil with a boiling point of about 300 to 400°C, and Separated into residual oil (slurry oil). This heavy cycle oil, which has a boiling point approximately the same as that of the feedstock oil, is usually extracted as a product, but most of it is recycled to the reaction tower. The present inventors believe that this heavy cycle oil has already been treated at high temperatures under a crystalline zeolite-based catalyst, so it has high thermal stability at high temperatures, and is also stable under the zeolite-containing catalyst used in the present invention. The inventors have focused on the fact that the catalyst can exist as a liquid medium, and that its boiling point range and viscosity have favorable properties as a liquid medium in which the catalyst is suspended. In other words, a typical heavy cycle oil has a specific gravity (15/4℃) of 0.9 to 1.0, a kinematic viscosity of 15 to 1 centistokes at 50℃, a pour point of +20 to -10℃, and a boiling point range.
250~400℃, sulfur content 0.1~2.0wt%, nitrogen content 0.01~
Shows properties of 0.5wt%. However, as can be seen from this property, there are many sulfur and nitrogen substances that poison the catalyst, and even if these poisonous substances are in small amounts, they can poison the metal components of the catalyst used in the present invention. Therefore, in order to use it as a liquid medium,
Needs to be removed. The removal method is not particularly limited, but a hydrodesulfurization treatment commonly used in industry can be used. Hydrodesulfurization treatment involves treating heavy cycle oil at a temperature of 300-400°C and 20-150Kg/cm ² G in the presence of a conventional hydrodesulfurization catalyst such as cobalt-molybdenum-alumina or nickel-molybdenum-alumina.
pressure, LHSV0.1~10h ^-1 , hydrogen to oil ratio 50~
Performed by contacting under the condition of 10000Nm ³ /Kl,
It is necessary to keep the sulfur content at most 0.5wt% and the nitrogen content at most 0.1wt%, preferably at most 0.1wt% sulfur and 0.05wt% or less. If the desulfurized heavy cycle oil is subsequently subjected to catalytic dewaxing treatment, it becomes a more preferred liquid medium. Although it does not impair catalytic activity when used as a liquid medium without catalytic dewaxing,
At the beginning of the reaction, the paraffin contained in the desulfurized heavy cycle oil is decomposed by the crystalline zeolite catalyst component, resulting in a decrease in the liquid medium, so it is also possible to hydrodesulfurize the desulfurized heavy cycle oil after catalytic dewaxing. . Catalytic dewaxing treatment improves pour point
This reaction uses a medium-pore size zeolite such as ZSM-5 zeolite, which can selectively eliminate wax content, as a catalyst. Already industrialized methods include Mobil Oil's MDDW method using ZSM-5 zeolite, and mordenite. There is a dewaxing method developed by British Petroleum that uses zeolite. In addition, among the crystalline zeolites described as crystalline zeolites that can be used in the present invention, this can also be achieved by using as a catalyst a crystalline zeolite with a medium pore size of 5 to 9 Å. The reaction conditions for catalytic dewaxing vary depending on the type of catalyst, but usually 250~
Temperature of 400℃, pressure of less than 100Kg/cm ² G,
Perform at LHSV0.1~10h ^-1 . Although the obtained dewaxed oil can be used as a liquid medium as it is, it is preferable to remove the fraction with a boiling point of 300° C. or lower produced by decomposition of the wax content by distillation. The liquid medium thus obtained is mixed with the catalyst,
The slurry is used for the reaction. The mixing ratio of the catalyst is 5 to 50 wt% in concentration in the slurry, and the catalyst is prepared in advance into a powder of 50 μm or less and mixed, or/and mixed with a liquid medium and then pulverized to form a powder of 50 μm or less.
The thickness is preferably 5 μm or less, preferably 5 μm or less. EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to the following unless it exceeds the gist thereof. Preparation of crystalline zeolite Crystalline zeolite was produced as follows. Water glass, lanthanum chloride, water to 36Na ₂ 0・La ₂ O ₃・
Mixed to have a molar ratio of 80SiO ₂・1600H ₂ O,
Add an appropriate amount of hydrochloric acid to this, and the pH of the above mixture becomes 9.
After this, tri-n-propylamine, n-propyl bromide, and methyl ethyl ketone were added as organic compounds 20 times the number of moles of La ₂ O ₃ , mixed well, and placed in a stainless steel autoclave (No. 1). The above mixture was reacted at 100° C. for 1 day and then at 170° C. for 3 days while stirring at about 500 rpm. The composition of the obtained crystal, excluding organic compounds, is expressed in dehydrated form as 0.4Na ₂ O・La ₂ O ₃・
It was _80SiO2 . This is called crystalline lanthanum silicate. Next, add silica sol, sodium aluminate, caustic soda and water to 10Na ₂ O・Al ₂ O ₃・46SiO ₂・1300H ₂ O
Diglycolamine was added as an organic compound 18 times the number of moles of Al ₂ O ₃ and mixed well, and the mixture was placed in a stainless steel autoclave (No. 1). The above mixture was reacted at 160° C. for 3 days under autogenous pressure while stirring at about 500 rpm. As a result of chemical analysis of the obtained white fine crystalline substance,
It contained 1.8 wt% Na and 0.8 wt% N, and the silica to alumina molar ratio was 27. This is called DGA zeolite. These two high silica zeolites were then washed with water and then subjected to the following ion exchange treatment in order to convert them into acid forms.
First, organic nitrogen cations were removed by firing at 550°C for 5 hours. Next, soak it in 1N hydrochloric acid,
After being treated at 80°C for 7 days, it was washed with ion-exchanged water until the pH of the washing water reached 6, and dried at 110°C for 12 hours to finally obtain hydrogen ion type crystalline zeolite. Preparation of catalyst The catalyst was manufactured as follows. After steaming the precipitated iron obtained by adding aqueous ammonia to an aqueous ferric nitrate solution with ion-exchanged water, the crystallinity shown in the preparation of crystalline zeolite was adjusted so that the weight ratio of iron oxide to crystalline zeolite was 1:1. Mixed with lanthanum silicate. The mixture was dried at 130°C, impregnated with an aqueous ruthenium trichloride solution having a ruthenium content of 1 wt%, dried at 130°C for 3 hours, and then calcined at 500°C for 3 hours to obtain a catalyst. This is called STG-1. In addition, a catalyst produced in exactly the same manner except that DGA zeolite shown in the preparation of crystalline zeolite was used instead of crystalline lanthanum silicate was used as STG.
-2. Further, a catalyst made by mechanically mixing BASF's zinc and chromium-based methanol synthesis catalyst and crystalline lanthanum silicate at a weight ratio of 1:1 and having a particle size of 50 μm or less is referred to as STG-3. In addition, vanadium oxide and crystalline lanthanum silicate were mixed at a weight ratio of 1:1, impregnated with an aqueous ruthenium trichloride solution with a ruthenium content of 1 wt%, and dried at 130°C for 3 hours.
The powder catalyst having a diameter of less than m is called STG-4. Preparation of liquid medium A suspension was prepared as follows. Heavy cycle oil with the properties shown in Table 1 collected from a catalytic cracker using desulfurized vacuum gas oil as raw material was used as KF702 manufactured by Ketsutien.
Pre-sulfurization of cobalt-molybdenum-alumina-based hydrodesulfurization catalyst (When a hydrodesulfurization catalyst is subjected to a desulfurization reaction, it is necessary to sulfurize the metal components in the catalyst, and this operation is called presulfurization. If cobalt and molybdenum are not sulfided, their desulfurization activity will be low and undesirable side reactions such as decomposition will occur.For this reason, pre-sulfurization is necessary to convert the above metal components into sulfides and obtain the best activity. ), then 380℃, 45Kg/cm ² G,
The treatment was carried out under the conditions of LHSV=1 h ^-1 and hydrogen to oil ratio of 500 Nm ³ /Kl. Next, some of the desulfurized oil is of the hydrogen type mentioned above.
DGA zeolite was mixed and molded with paemite alumina gel as a matrix at a weight ratio of 1:1, and then calcined at 550°C.
Kg/cm ² G, LHSV=1.5h ^-1 , hydrogen to oil ratio 200N
Catalytic dewaxing treatment was carried out under the conditions of m ³ /Kl. Subsequently, the dewaxed oil was separated into fractions with a boiling point below 300°C and above 300°C in a distillation apparatus, and the fraction with a boiling point above 300°C was used as a liquid medium. Table 2 shows the properties of the desulfurized oil and the desulfurized and dewaxed oil.

【table】

【table】

[Table] In addition, in order to examine the effect of the sulfur content in the liquid medium on the catalyst, the same treatment was carried out except that the reaction temperature was 360°C in the hydrodesulfurization treatment, and the sulfur content was
0.07wt% desulfurized heavy cycle oil was prepared. Effect of s content in liquid medium Using a fixed bed flow-through actor, the effect of sulfur content in liquid medium on STG-2 catalyst was investigated.
Source gas with H ₂ /CO molar ratio 2 at 320℃, 20Kg/cm ²
When contacted with STG-2 catalyst under the condition of G, GHSV = 1000 h ^-1, the CO conversion rate was 91.5%. after that,
Heavy cycle oil with a sulfur content of 1.09wt% was heated at 320℃ for 20
After passing through the oil for 2 hours under the conditions of Kg/cm ² G and LHSV = 1000 h ^-1 under the flow of syngas, the catalyst activity was tested again under the same conditions, and as a result, the CO conversion rate decreased to 7%. Separately, similar experiments were conducted using desulfurized heavy cycle oils with different sulfur contents, and as shown in Table 3, there was no decrease in activity, and by performing desulfurization treatment, the oils could be used as the liquid medium of the present invention.

[Table] Example 1, 2 Sulfur content 0.02wt% produced in the section of liquid medium preparation
190 g of the STG-1 catalyst prepared in the crystalline zeolite section was mixed with 530 g of the liquid medium of The mixture was filled into a stainless steel suspended bed reaction tube. This slurry catalyst uses synthesis gas with a H ₂ /CO molar ratio of 2 at 300°C.
After pretreatment for 6 hours at normal pressure and gas flow rate of 50L/H,
The reaction was carried out using synthesis gas with a H ₂ /CO molar ratio of 2 or 1 as a raw material. The reaction conditions and reaction results are shown in Table 4, and CO and H ₂ were converted to hydrocarbons with a high conversion rate, and a particularly high yield of hydrocarbons in the gasoline boiling point range was obtained. An even more significant feature is that the catalyst bed maintains a uniform temperature throughout the reaction period, and there is no localized heat generation that occurs in fixed bed reactors. Furthermore, there was almost no change in the height of the slurry layer during the 50 hour reaction period, and as a result of measuring the weight of the slurry catalyst taken out after the reaction, 95% of the liquid medium was recovered. Therefore, it can be seen that the liquid medium of the present invention can be used in a suspended bed reaction without impairing the performance of the catalyst used in the reaction applied to the present invention, and without being decomposed itself.

[Table] Example 3 Results when the reaction was carried out in exactly the same manner as in Example 2, except that the desulfurized heavy cycle oil prepared in the liquid medium preparation section was used as the liquid medium and the space-time velocity was changed. are also shown in Table 4. Since the liquid medium used here has not undergone catalytic dewaxing treatment, the wax content is decomposed by the zeolite component in the STG-1 catalyst under the reaction conditions, producing hydrocarbons below the gasoline boiling point range as a by-product and starting the reaction. A decrease in the level of the liquid medium in the reaction tube was observed over a period of approximately 10 hours. However, after that, there was no change in the level of the catalyst layer, and as in Example 2, a uniform reaction temperature was maintained and only the conversion reaction from synthesis gas to hydrocarbons proceeded effectively. After the reaction was completed, the liquid medium was recovered and the recovery rate was 83 wt%. Therefore, desulfurized heavy cycle oil can also be used as the liquid medium of the present invention without impairing the catalyst activity, although there is some loss due to decomposition at the beginning of use. Example 4 Sulfur content 0.02wt% produced in the section of liquid medium preparation
of the liquid medium prepared in the section of catalyst preparation.
Mix 110g of STG-2 catalyst, and the average catalyst particle size is
Example 4 shows the results of a synthesis gas conversion reaction using a slurry catalyst obtained by pulverizing the slurry to a size of 5 μm or less. The experimental equipment and method were the same as in Example 2, and the reaction results are shown in Table 5 below. Even in this method, there was almost no decrease in catalyst activity or change in the height of the catalyst slurry layer during the 24-hour reaction time, and the recovery rate of the liquid medium after the reaction was 96%.
It was hot. Example 5 In Example 4, the slurry catalyst obtained by using the STG-3 catalyst shown in the section of catalyst preparation instead of the STG-2 catalyst was packed, and synthesis gas with an H ₂ /CO molar ratio of 2 was used. , reaction temperature 380℃, reaction pressure 40Kg/
The results of the reaction conducted under the conditions of cm ² G and space-time velocity of 100 (/catalyst/h) are shown in Table 5 as Example 5.
The liquid medium used here does not poison the methanol synthesis catalyst components consisting of zinc and chromium.
During the reaction period, the entire layer of the catalyst slurry maintained a uniform temperature distribution of ±5°C and exhibited stable activity. Furthermore, even at a relatively high temperature of 380°C, there was almost no loss in capacity due to decomposition of the liquid medium itself, and the recovery rate after the reaction was 96 wt%.

【table】

[Table] Example 6 In Example 5, STG was used instead of STG-3 catalyst.
The results of the reaction conducted under the same conditions except that the -4 catalyst was used and the reaction temperature was 280° are also listed as Example 6 in Table 5 above. In this case as well, high CO and H ₂ conversion rates were obtained, the yield of gasoline fraction reached 74.2 wt%, and there was no abnormal heat generation in the catalyst slurry layer, allowing stable operation.

Claims (1)

[Claims] 1. In a method for producing hydrocarbons by contacting a composite catalyst of a metal or/and metal oxide and crystalline zeolite with catalytic activity to hydrogenate carbon monoxide with synthesis gas, Suspending the catalyst in a liquid medium consisting of a heavy aromatic hydrocarbon mixture having a boiling point of 250°C or higher and an aromatic content of 50% by weight or higher obtained by hydrodesulfurization treatment of heavy cycle oil; A method for producing hydrocarbons, which comprises bringing a liquid into contact with synthesis gas.