JP4921788B2 - Process for producing ethylene and propylene - Google Patents

Description

  The present invention relates to a process for producing ethylene and propylene from a hydrocarbon feedstock by catalytic conversion. More specifically, the present invention is a method for producing ethylene and propylene from a hydrocarbon raw material by catalytic conversion, wherein a hydrocarbon raw material containing 20% by mass or more of at least one olefin having 4 to 12 carbon atoms, The present invention relates to a method for producing ethylene and propylene by contacting with a zeolite-containing shaped catalyst in a reactor and conducting a catalytic conversion reaction of the at least one olefin having 4 to 12 carbon atoms.

There are many known methods for catalytic conversion of hydrocarbon raw materials containing olefins using a catalyst containing zeolite, and hydrocarbon raw materials containing olefins are converted into catalysts containing zeolite. There have also been many reports on methods of catalytic conversion using ethylene to produce ethylene and propylene.
However, it is difficult for the following reasons to carry out catalytic conversion of hydrocarbon raw materials containing olefins using a catalyst containing zeolite to produce ethylene and propylene efficiently and stably over a long period of time. It was.

  Ethylene and propylene are intermediates for the conversion reaction of olefins to aromatic hydrocarbons in the presence of a zeolite catalyst, and are converted to aromatic hydrocarbons by successive reactions. Accordingly, when catalytically converting a hydrocarbon raw material containing olefins using a catalyst containing zeolite to produce ethylene and propylene, the activity and reaction conditions of the catalyst are required in order to obtain the desired product in a high yield. Need to be strictly controlled. That is, if the activity of the catalyst is too high or the contact time is too long, the produced ethylene and propylene are converted into aromatic hydrocarbons by a sequential reaction. Conversely, if the activity of the catalyst is too low or the contact time is too short, the yields of ethylene and propylene will decrease.

On the other hand, since olefins have high reactivity, when a catalytic conversion reaction is performed on a hydrocarbon raw material containing olefins using a catalyst containing zeolite, carbonaceous precipitation (coking) is likely to occur on the surface of the catalyst. For this reason, while the conversion reaction is continuously performed, the catalyst deteriorates due to coking (coking deterioration), and the catalytic activity immediately decreases.
In general, a catalyst whose catalytic activity has decreased due to coking deterioration can be recovered by heating it in the presence of an oxygen-containing gas and burning off the coke.

However, when this regeneration operation is repeated, the catalytic activity is not sufficiently recovered. This is because, in the above regeneration operation, water vapor is generated by the combustion of coke, and when the zeolite is heated in the presence of this water vapor, the aluminum that is the active site of the zeolite is desorbed from the zeolite crystals, so that the catalyst becomes permanent. This is due to the occurrence of mechanical degradation (regeneration degradation).
As described above, when a catalytic conversion reaction of a hydrocarbon raw material containing olefins is performed using a catalyst containing zeolite, coking is particularly likely to occur. Very easy to happen.

Patent Document 1 discloses a method of converting paraffin, olefin and / or cycloparaffin (naphthene) having 5 or more carbon atoms into aromatic hydrocarbon, ethylene and propylene using proton type ZSM-5 zeolite. However, in this process, aromatic hydrocarbons are obtained in a relatively high yield, but the yields of ethylene and propylene are low.
Patent Document 2 discloses a method of converting olefins and paraffins having 2 to 4 carbon atoms into aromatic hydrocarbons, ethylene and propylene using proton type ZSM-5 zeolite. However, even in this method, aromatic hydrocarbons are obtained in a relatively high yield, but the yields of ethylene and propylene are low.

Patent Documents 3 and 4 disclose a method of converting butene to ethylene and propylene using an aluminophosphate molecular sieve. However, even in this method, the yields of ethylene and propylene are low.
Patent Document 5 discloses a method for producing ethylene and propylene by bringing a hydrocarbon raw material comprising a mixture of paraffin and olefin having 4 or more carbon atoms having a specific composition into contact with proton-type ZSM5 zeolite. . However, in this method, since the conversion rate is low, it is necessary to recycle a large amount of unreacted raw materials.

Patent Document 6 discloses a method of converting a hydrocarbon having 3 to 20 carbon atoms into ethylene and propylene using a specific proton-type ZSM5 zeolite containing phosphorus. However, in this method, only the initial performance after 1 minute of the raw material supply is evaluated for the case where olefin is used as the raw material.
A feature common to the above methods is that proton type zeolite is used. In the case of proton-type zeolite, since the acid strength is generally strong, ethylene and propylene are easily converted into aromatic hydrocarbons sequentially, and it is difficult to improve the yield of ethylene and propylene. In addition, when a hydrocarbon raw material containing an olefin is used, coking deterioration and regeneration deterioration are likely to occur.

Patent Document 7 discloses a zeolite catalyst that does not contain a proton different from a conventional zeolite catalyst that contains a proton, and a method for converting a hydrocarbon raw material into ethylene, propylene, and a monocyclic aromatic hydrocarbon using this catalyst. ing.
The catalyst used in this method is effective in that it hardly causes regeneration degradation, but the problem relating to coking degradation has not been solved. Accordingly, when a hydrocarbon raw material containing a large amount of olefin is used, coking deterioration is likely to occur.

Patent Document 8 discloses a method of converting an olefin having 4 to 12 carbon atoms into ethylene and propylene using an aprotic intermediate pore size zeolite containing a group IB metal having a silica alumina molar ratio of 200 to 5000. Yes.

JP-A-49-41322 JP 50-49233 A U.S. Pat. No. 4,527,001 U.S. Pat. No. 4,613,721 Japanese Patent Laid-Open No. 3-27327 JP-A-6-73382 International Publication No. 1996/013331 Pamphlet International Publication No. 2000/010948 Pamphlet

  The present invention relates to a method for producing ethylene and propylene from a hydrocarbon raw material by catalytic conversion, more specifically, a method for producing ethylene and propylene from a hydrocarbon raw material by catalytic conversion, wherein at least one kind of carbon number 4 to By contacting a hydrocarbon raw material containing 20% by mass or more of 12 olefins with a zeolite-containing shaped catalyst in a reactor, and performing a catalytic conversion reaction of the at least one olefin having 4 to 12 carbon atoms, The present invention relates to a method for producing ethylene and propylene.

  In the conventionally proposed technology, first, when proton type zeolite is used as a catalyst, since the catalyst generally has strong acid strength, ethylene and propylene are easily converted into aromatic hydrocarbons in succession. It is difficult to improve the yield of propylene. In addition, when a hydrocarbon raw material containing olefin is used, there is a problem that coking deterioration and regeneration deterioration are likely to occur.

Patent document 8 is mentioned as an example using the aprotic zeolite proposed in recent years. In Examples of Patent Document 8, it is reported mainly about zeolite having a silica-alumina molar ratio (SiO ₂ / Al ₂ O ₃ molar ratio) of 300, and the examples at a silica-alumina molar ratio of 3,000 are also reported. Are listed. However, only examples of reaction results up to 24 hours are disclosed in examples of molded catalyst using a silica alumina molar ratio of 300. The examples with a silica-alumina molar ratio of 3000 are only examples in which zeolite powder is compression-molded, and no examples of molded-form catalysts that can be industrially implemented are shown. In addition, no mention is made of the influence of the concentration of diolefins in the hydrocarbon feed used on the deterioration of coking.

According to the study by the present inventors, the zeolite catalyst disclosed in Patent Document 8, that is, (1) an intermediate pore size zeolite having a pore size of 5 to 6.5 mm, and (2) substantially a proton (3) Even when a zeolite catalyst containing at least one metal selected from the group consisting of metals belonging to Group IB of the periodic table is used, zeolite having a low silica-alumina molar ratio is suitable for coking deterioration. When the tolerance is industrially implemented, it is not yet sufficient, and there is a problem that frequent regeneration is necessary, or deterioration becomes more remarkable when the concentration of the diolefin compound contained in the raw material hydrocarbon becomes high. is there. Removal of diolefins in the raw material requires a raw material pretreatment purification such as distillation separation and partial hydrogenation, which is extremely disadvantageous for industrial implementation.
On the other hand, when the silica-alumina molar ratio is high, it becomes extremely difficult to carry silver by ion exchange of the molded catalyst, and the load in the catalyst preparation process becomes large in order to obtain industrially sufficient activity. There is a point.

  Under such circumstances, the present inventors have intensively studied to solve the above problems, and as a result, by making the silica-alumina ratio of the zeolite used for the zeolite molded body catalyst into a specific range, the zeolite-containing molded Suppressing coking deterioration and regeneration deterioration of the catalyst, both of which are problems in the method of converting olefin-containing hydrocarbon raw materials to ethylene and propylene using a solid catalyst, and subjecting them to reactions while containing diolefins in the raw material hydrocarbons As a result, it has been found that ethylene and propylene can be stably and efficiently produced over a long period of time by a simple method without imposing a great burden on catalyst preparation, and the present invention has been completed.

That is, the present invention is a method for producing ethylene and propylene by catalytic conversion from a hydrocarbon raw material as described below.
[1] A hydrocarbon raw material containing 20% by mass or more of at least one kind of olefin having 4 to 12 carbon atoms is brought into contact with the zeolite-containing shaped catalyst in a reactor, and the at least one kind of carbon atoms having 4 to 12 carbon atoms is contacted. Is a method for producing ethylene and propylene by carrying out a catalytic conversion reaction of olefin, wherein the zeolite in the zeolite-containing shaped catalyst has the following requirements (1), (2), (3) and (4): And a method for producing ethylene and propylene.
(1) The zeolite is an intermediate pore size zeolite having a pore size of 5 to 6.5 mm.
(2) The zeolite is substantially free of protons.
(3) The zeolite contains at least one metal selected from the group consisting of metals belonging to Group IB of the Periodic Table.
(4) The silica alumina molar ratio (SiO ₂ / Al ₂ O ₃ molar ratio) of the zeolite is 800 or more and 2,000 or less.
[2] The above [1] to [1], wherein the hydrocarbon raw material contains 50% by mass or more of the at least one olefin having 4 to 12 carbon atoms based on the weight of the hydrocarbon raw material. The manufacturing method of ethylene and propylene of description.
[3] The hydrocarbon raw material contains at least one diolefin compound having 3 to 12 carbon atoms in an amount of 2.5% by mass or less based on the weight of the hydrocarbon raw material. The process for producing ethylene and propylene according to [1] or [2].
[4] The ethylene according to [1] to [3] above, wherein the zeolite in the zeolite-containing shaped catalyst supports silver and an alkali metal and substantially does not contain a proton. Propylene production method.
[5] The method for producing ethylene and propylene according to the above [1] to [4], wherein the zeolite in the zeolite-containing shaped catalyst is selected from the group consisting of ZSM-5 type zeolite.
[6] The above-mentioned [1] to [5], wherein the zeolite-containing shaped catalyst is heat-treated at a temperature of 500 ° C. or higher in the presence of water vapor prior to contact with the hydrocarbon raw material. ] The manufacturing method of ethylene and propylene of description.
[7] The method for producing ethylene and propylene according to the above [1] to [6], wherein the reactor is an adiabatic fixed bed reactor.
[8] The reaction conditions of the catalytic conversion reaction are: reaction temperature: 500 to 580 ° C., partial pressure of hydrocarbon raw material: 0.05 to 0.3 MPa, weight hourly space velocity: 2 to 10 hr ⁻¹ The method for producing ethylene and propylene according to the above [1] to [7].

  According to the zeolite-containing molded catalyst and the production method of the present invention, ethylene and propylene can be produced efficiently and stably from an olefinic hydrocarbon raw material. Since the zeolite-containing shaped catalyst used in the method of the present invention has extremely high resistance to deterioration, it can be stably produced in a high yield over a long period of time by a simple method. Moreover, even if it contains diolefin compounds in the raw material hydrocarbon mixture, it can be used for the reaction as it is within 2.5% by mass. A great load is not applied in the catalyst preparation process. These features are extremely advantageous for industrial implementation of the present invention.

Hereinafter, the present invention will be described in detail.
In the method of the present invention, a hydrocarbon raw material containing 20% by mass or more of at least one olefin having 4 to 12 carbon atoms is used as a raw material for producing ethylene and propylene.
In the method of the present invention, the “hydrocarbon raw material” means a hydrocarbon having 1 to 12 carbon atoms, for example, a normal paraffin having 1 to 12 carbon atoms, isoparaffin, olefin, cycloparaffin (naphthene), or cycloparaffin having a side chain alkyl group. A raw material mainly containing at least one selected from the group consisting of:

In the method of the present invention, the hydrocarbon raw material contains at least one olefin having 4 to 12 carbon atoms in an amount of 20% by mass or more based on the weight of the hydrocarbon raw material.
The term “olefin”, which is a constituent requirement of the method of the present invention, is used as a term that includes cycloparaffins in addition to linear, branched, and cyclic olefins.

If the olefin content is less than 20% by mass, the yield of ethylene and propylene becomes insufficient. Therefore, in the method of the present invention, the hydrocarbon raw material contains at least one olefin having 4 to 12 carbon atoms, It is contained in an amount of 20% by mass or more, preferably 30% by mass or more, more preferably 40% by mass or more, and most preferably 50% by mass or more.
The hydrocarbon raw material may contain a small amount of oxygen-containing compounds such as tertiary butanol, methyl tertiary butyl ether, and methanol as impurities.

  In the method of the present invention, the hydrocarbon raw material may contain diolefin (diene) compounds such as propadiene, butadiene and pentadiene, and acetylene compounds such as methylacetylene up to 2.5% by mass. These diolefin compounds are rich in polymerizability and are well known to cause coking deterioration. Usually, it is obvious that diene compounds are preferably reduced to the minimum by treatment such as distillation separation, partial hydrogenation, etc., but such pretreatment is said to be extremely disadvantageous when carried out industrially. I must. However, surprisingly, when the zeolite-containing shaped catalyst of the present invention is used, as described above, if the concentration of the hydrocarbon raw material containing diolefin compounds is 2% by mass or less, pretreatment is performed. It can be used as a raw material.

Examples of preferred hydrocarbon raw materials that can be used in the method of the present invention include the following.
(1) Partial hydrogenation of C4 and C5 fractions separated from products obtained by pyrolyzing petroleum hydrocarbons such as naphtha, and diolefins in the C4 and C5 fractions to olefins Distillate,
(2) a fraction obtained by separating and removing part or all of butadiene and isobutene from the C4 fraction,
(3) a fraction obtained by separating and removing part or all of isoprene and cyclopentadiene from the C5 fraction;
(4) C4 fraction and gasoline fraction separated from products obtained by fluid catalytic cracking (FCC) of petroleum hydrocarbons such as vacuum gas oil, and (5) C4 fraction and gasoline separated from coker. Fraction.
Moreover, these may be used independently or may be used in mixture of 2 or more types.

In the method of the present invention, at least one olefin having 4 to 12 carbon atoms contained in the hydrocarbon raw material is brought into contact with the specific zeolite-containing shaped catalyst in the reactor. By carrying out the catalytic conversion reaction, a reaction mixture containing ethylene and propylene is obtained, and ethylene and propylene are separated from the obtained reaction mixture.

In the method of the present invention, so-called “medium pore diameter zeolite” having a pore diameter of 5 to 6.5 mm is used as the zeolite in the zeolite-containing shaped catalyst.
The term “medium pore size zeolite” means that the pore size range is that of a small pore size zeolite represented by type A zeolite, and that of a large pore size zeolite represented by mordenite, X type or Y type zeolite. “Zeolite in the middle of the pore diameter” means a zeolite having a so-called oxygen 10-membered ring in its crystal structure.

Examples of the intermediate pore size zeolite include ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-21, ZSM-23, ZSM-35, ZSM-38, etc. Among them, ZSM-5 ZSM-5 type zeolite such as ZSM-11 and ZSM-8, and ZSM-38 are preferable.
P.P. A. Jacobs and J.M. A. Martens “Stud. Surf. Sci. Catal.” 33, P.M. 167-215 (1987, The Netherlands), zeolite similar to ZSM-5 and ZSM-11 can also be used.
Of these, ZSM-5 is particularly preferred.

As the zeolite of the zeolite-containing shaped catalyst in the method of the present invention, a zeolite containing substantially no proton is used.
In the method of the present invention, “substantially free of protons” means that the amount of protons (acid amount) in the zeolite determined by the liquid phase ion exchange / filter droplet method described later is about 0.00 per gram of the zeolite. It means 02 mmol or less. Preferably, the zeolite has a proton amount of 0.01 mmol or less per gram of the zeolite.
The liquid phase ion exchange / filter droplet method is known as Intrazeolite Chemistry, “ACS Symp. Ser.”, 218, P369-382 (1983), The Chemical Society of Japan, [3], P. 521-527 (1989).

Measurement of the amount of protons using this method can be performed as follows.
The zeolite-containing shaped catalyst calcined in air is subjected to ion exchange treatment using an aqueous NaCl solution, and then the zeolite is recovered by filtration and a filtrate is obtained. The recovered zeolite is washed with pure water, and the entire amount of the resulting washing solution is collected and mixed with the above filtrate. The amount of protons in the obtained mixed solution is determined by neutralization titration, and the value converted to the weight of zeolite contained in the zeolite-containing shaped catalyst is defined as the amount of protons in the zeolite.

It is known that ammonium ion type and polyvalent metal cation type zeolite (for example, rare earth metal cation type zeolite) generates protons by heat treatment.
Therefore, prior to the measurement of the proton amount by the above method, the zeolite-containing shaped catalyst needs to be calcined.

As the zeolite of the zeolite-containing shaped catalyst in the method of the present invention, at least one selected from the group consisting of metals belonging to Group IB of the periodic table (hereinafter referred to as “Group IB metal”), that is, copper, silver, and gold. Those containing the above metals are used. Preferred group IB metals include copper and silver, and more preferably silver.
In the present invention, “periodic table” means CRC Handbook of Chemistry and Physics, 75th edition [(David R. Lide et al., CRC Press Inc. published (1994-1995)], pages 1-15. The listed periodic table shall be shown.

The above-mentioned “containing a group IB metal” means containing a group IB metal in a corresponding cation state. However, the group IB metal may be further contained in a state other than the cation in addition to the one contained in the zeolite in the cation state. For example, the group IB metal may be contained in the oxide state. Good.
As an example of a method for containing a group IB metal in zeolite, a zeolite not containing a group IB metal is contained by a method of treating by a known ion exchange method.
When the group IB metal is contained in the zeolite by the ion exchange method, it is necessary to use a salt of the group IB metal. Examples of the group IB metal salt include silver nitrate, silver acetate, silver sulfate, copper chloride, copper sulfate, copper nitrate, and gold chloride.

There is no strict limitation on the amount of Group IB metal contained in the zeolite-containing shaped catalyst as the Group IB metal cation, but the silica alumina molar ratio of the zeolite used in the present invention is 800 to 2,000, and Since the ion exchange is carried, the content of the group IB metal is naturally determined from the exchange capacity and the zeolite content in the zeolite-containing shaped catalyst. Therefore, when the exchange rate of the group IB metal cation with respect to the zeolite exchange site is shown, the activity is not sufficient when the exchange rate is low, and the load of the ion exchange preparation process is increased to increase the exchange rate. It is in the range of 5% to 80%, preferably in the range of 25% to 75%, more preferably in the range of 30 to 70%.
The content of the group IB metal in the zeolite can be determined by a known method such as an X-ray fluorescence analysis method.

  Since the zeolite of the zeolite-containing shaped catalyst in the method of the present invention is a zeolite substantially free of protons as described above, the remaining ion exchange sites exchanged with the group IB metal cation are alkali metal and alkaline earth. Ion exchange is performed with a cation of at least one metal selected from the group of metals. It is preferably exchanged with at least one metal cation selected from alkali metals, more preferably at least one metal cation selected from the group consisting of sodium and potassium.

That is, the zeolite of the zeolite-containing shaped catalyst in the method of the present invention is a zeolite containing both at least one metal selected from alkali metals and alkaline earth metals and a group IB metal.
Examples of the method of containing at least one metal selected from alkali metals and alkaline earth metals in zeolite include a method of carrying out ion exchange in a corresponding cation state.
The content of at least one metal selected from alkali metals and alkaline earth metals varies depending on the type of metal, but is supported by ion exchange, so the exchange capacity, the zeolite content in the zeolite-containing shaped catalyst, It is determined automatically from the amount of ion exchange supported by the group IB metal.

  When preparing the zeolite-containing shaped catalyst of the present invention, the order and the number of times of the method of containing at least one metal selected from alkali metals and alkaline earth metals and the method of containing a group IB metal are particularly limited. There is no. However, in any case, as described above, it is necessary that the zeolite after containing the metal does not substantially contain protons.

  For example, as a zeolite-containing molded catalyst of the present invention, when prepared in a silver / sodium cation exchange type, some silver cannot be supported as a silver cation when an alkali component is present in the zeolite-containing molded catalyst. At the time of molding, it is necessary to convert the zeolite to the proton type. Therefore, the zeolite-containing shaped catalyst formed as a proton type zeolite is first exchanged into sodium type (preferably using a sodium nitrate aqueous solution) and then converted into sodium type (non-proton type), and then the silver cation is exchanged and introduced. The method (preferably using an aqueous silver nitrate solution) is preferred.

The silica-alumina molar ratio (SiO ₂ / Al ₂ O ₃ molar ratio) of zeolite in the zeolite-containing shaped catalyst in the method of the present invention is essential to be 800 or more and 2,000 or less.
When the silica-alumina molar ratio is less than 800, the deterioration of the zeolite-containing molded catalyst is accelerated by coking associated with the conversion reaction, for example, the switching frequency when the present invention is carried out in the fixed-bed two-column swing method becomes faster. The replay frequency also increases. Therefore, the progress of regeneration deterioration is also accelerated. In addition, when diolefin compounds are included in the raw material hydrocarbon, coking deterioration becomes more remarkable, the switching frequency becomes even faster, and it will hinder the continuation of stable operation. In order to avoid this, it is necessary to treat the diolefin compounds in the raw material in advance, which is disadvantageous for industrial implementation.

On the other hand, if the silica-alumina molar ratio exceeds 2,000, the catalyst preparation problem is large. In order to maintain the catalytic activity of the high-silica alumina ratio zeolite-containing shaped body catalyst and to prepare the same silver content, it is necessary to increase the ion exchange rate of the zeolite. However, when the zeolite-containing shaped catalyst of the present invention is prepared into an aprotic, group IB metal exchange type by ion exchange, the ion exchange efficiency deteriorates as the exchange rate increases.

  In order to avoid this, it is necessary to increase the metal concentration in the exchange liquid. When the silica-alumina molar ratio of the zeolite exceeds 2,000, both the ion exchange with the alkali metal and the ion exchange with the group IB metal are difficult to proceed. It takes. In addition, there is a problem that an excessive amount of chemical solution is required and the amount of waste liquid generated is excessive, which is disadvantageous.

The silica alumina molar ratio of the zeolite contained in the zeolite-containing shaped catalyst of the present invention is preferably 900 or more and 1,800 or less, more preferably 1,000 or more and 1,600 or less.
The silica-alumina molar ratio of zeolite can be determined by a known method, for example, by completely dissolving zeolite in an aqueous alkali solution or an aqueous hydrofluoric acid solution, and analyzing the resulting solution by plasma emission spectroscopy.

As a zeolite of the zeolite-containing shaped catalyst in the method of the present invention, a metalloaluminosilicate in which a part of aluminum atoms constituting the zeolite skeleton is substituted with elements such as Ga, Fe, B, Cr, etc., and aluminum constituting the zeolite skeleton It is also possible to use metallosilicates in which all atoms are substituted with the elements as described above.
In that case, after converting the content of the above-mentioned element in the metalloaluminosilicate or metallosilicate to the number of moles of alumina, the silica-alumina molar ratio is calculated.

  If desired, the zeolite-containing molded body catalyst in the method of the present invention can be added to the above-mentioned zeolite-containing catalyst for the purpose of suppressing coking deterioration and improving the yields of ethylene and propylene, and V, Cr, Mo, W, Mn. , Pt, Pd, Fe, Ni, Zn, Ga, etc., may be used by further containing at least one metal selected from the group consisting of metals belonging to groups IIb, III, Vb, VIb, VIIb, and VIII. .

  Prior to contact with the hydrocarbon raw material, the zeolite-containing molded catalyst in the method of the present invention is more than 500 ° C. in the presence of water vapor, for the purpose of further improving the resistance to coking deterioration. Heat treatment can be performed at temperature. The heat treatment is preferably performed at a temperature of 500 ° C. or higher and 900 ° C. or lower and a water vapor partial pressure of 0.01 atmosphere or higher.

  The zeolite-containing shaped catalyst in the method of the present invention may cause coking deterioration when used in a conversion reaction for a long period of time, but in that case, in the air or a mixed gas composed of oxygen and an inert gas, By burning and removing coke on the catalyst at a temperature of 700 ° C., it is possible to regenerate the catalyst that has undergone coking deterioration (hereinafter, this process is referred to as “regeneration process”).

The zeolite-containing shaped catalyst in the method of the present invention is usually a porous refractory inorganic oxide such as alumina, silica, silica / alumina, zirconia, titania, diatomaceous earth, clay, etc. as a binder or a diluent for molding (matrix). A mixture obtained by mixing with the above zeolite is molded, and the obtained molded body is used as a zeolite-containing molded body catalyst.
When using a matrix or a binder, the content thereof is preferably in the range of 10 to 90% by mass, more preferably 20 to 50% by mass, based on the total weight of the zeolite and the matrix or binder.

In the method of the present invention, the zeolite-containing molded catalyst as described above is charged into a reactor, and catalytic conversion reaction of at least one olefin having 4 to 12 carbon atoms is performed. In the catalytic conversion reaction of olefins having 4 to 12 carbon atoms, olefins having 4 to 12 carbon atoms in the raw material hydrocarbon are converted to ethylene and propylene with high selectivity, and paraffins coexisting in the raw material hydrocarbon are substantially reacted. However, it is preferable to carry out under the following conditions. The reaction temperature is preferably 400 to 600 ° C, more preferably 500 to 580 ° C. The partial pressure of the hydrocarbon raw material is desirably low, and is usually 0.01 to 1 MPa, preferably 0.05 to 0.3 MPa. The weight hourly space velocity WHSV of the hydrocarbon feed relative to the weight of the zeolite-containing shaped catalyst is more preferably in the range of ¹ to 100 hr ⁻¹ , preferably 2 to 10 hr ⁻¹ . The contact time between the hydrocarbon raw material and the zeolite-containing catalyst is preferably 5 seconds or less, more preferably 1 second or less.

  The hydrocarbon raw material may be a mixture with a dilution gas. As a dilution gas, an inert gas such as hydrogen, methane, water vapor, or nitrogen can be used, but preferably hydrogen dilution is not performed. That is, hydrogen is used to suppress the coking deterioration of the catalyst, but at the same time, a hydrogenation reaction of produced propylene occurs, which has an adverse effect of lowering propylene purity (propylene / (propylene + propane)). In the method of the present invention, it is preferable not to dilute hydrogen because the coking deterioration of the catalyst is small and stable operation is possible without diluting hydrogen.

  When the conversion reaction is carried out under the condition that the paraffin does not substantially react, the olefin conversion reaction in the hydrocarbon raw material is selectively promoted, and the paraffin conversion reaction is suppressed. By-products such as ethane and propane are suppressed, and separation and purification of ethylene and propylene from the reaction mixture becomes easy.

In the method of the present invention, the reactor for bringing the hydrocarbon raw material into contact with the zeolite-containing shaped catalyst may be any of a fixed bed type, a moving bed type, a fluidized bed type or an air flow type.
Since the zeolite-containing shaped catalyst used in the method of the present invention hardly deteriorates due to coking, even if a fixed bed reactor is used, ethylene and propylene can be stably produced over a long period of time.

  In addition, the paraffin conversion reaction is a large endothermic reaction, and the olefin conversion reaction is a slightly endothermic reaction or an exothermic reaction, depending on the reaction conditions. Therefore, when the olefin in the hydrocarbon raw material is selectively reacted under the condition that the above paraffin does not substantially react, it is not necessary to supply reaction heat, and therefore, a one-stage adiabatic fixed bed with a simple structure. A reactor can also be used.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited at all by these examples.
In addition, the measuring method performed in the Example and the comparative example is as follows.

(1) Measurement of proton content by liquid phase ion exchange / filter drop method The 2.5 g zeolite-containing shaped catalyst obtained by firing in a mortar and calcined in air at a temperature of 400 to 600 ° C. was added at 3.4 mol / liter. Ion exchange is performed in 25 ml of NaCl aqueous solution for 10 minutes under ice cooling. After filtering the resulting mixture, the zeolite is washed with 50 ml of pure water, and the entire filtrate containing the water used for washing is recovered. This filtrate (including water used for washing) was neutralized and titrated with a 0.1N NaOH aqueous solution, and the proton content was determined from the neutralization point. This was determined from the zeolite content in the zeolite-containing shaped catalyst, based on the zeolite weight. Convert as

(2) Measurement of silica-alumina ratio of zeolite 0.2 g of zeolite is added to 50 g of 5N NaOH aqueous solution. This is transferred to a stainless steel micro cylinder with a Teflon (registered trademark) inner tube, and the micro cylinder is sealed. The zeolite is completely dissolved by holding in an oil bath for 15 to 70 hours. The obtained zeolite solution is diluted with ion-exchanged water, the silicon and aluminum concentrations in the diluted solution are measured with a plasma emission spectrometer (ICP apparatus), and the silica-alumina molar ratio of the zeolite is calculated from the results.
ICP device and measurement conditions Device: JOBIN YVON (JY138 ULTRACE) manufactured by Rigaku Denki Co., Ltd. Measurement conditions Silicon measurement wavelength: 251.60 nm
Aluminum measurement wavelength: 396.152 nm
Plasma power: 1.0 kW
Nebulizer gas: 0.28 L / min
Sheath gas: 0.3 to 0.8 L / min
Coolant gas: 13L / min

(3) Reaction conversion rate, yield The conversion rate (butene-based olefin conversion rate) is calculated by the following equation.
Conversion rate = (olefin concentration having 4 to 8 carbon atoms in raw material−butene concentration in product) / olefin concentration having 4 to 8 carbon atoms in raw material Ethylene and propylene yields are the concentrations of ethylene and propylene in the product (Mass%).
[Example 1]

Silica-alumina molar ratio of 1220 (by completely dissolving the zeolite-containing shaped catalyst was determined by measuring by the ICP method.) A is ZSM5 type zeolite molded catalyst containing the (SiO ₂ binder 30 wt% content, 1. 6 mmφ * 5 to 10 mmL) of H exchange type was dispersed in 1N sodium nitrate aqueous solution (10 cc / g-zeolite molding), and the ion exchange treatment at room temperature for 1 hour was repeated three times. Next, filtration, washing with water and drying were performed to prepare a Na exchange type ZSM-5 / SiO ₂ molded body catalyst. This was dispersed in a 0.0017N silver nitrate aqueous solution (10 cc / g-zeolite molding) and subjected to ion exchange treatment at room temperature for 2 hours. Next, the catalyst A was prepared by filtration, washing with water and drying.
The Ag content of catalyst A measured by fluorescent X-ray analysis was 0.095% by mass. That is, the silver cation occupancy (ion exchange rate) with respect to the zeolite exchange site (aluminum amount) was 46.2%.
Catalyst A was filled in a Hastelloy C reactor having an inner diameter of 27.2 mmφ, and steamed for 5 hours under the conditions of a temperature of 650 ° C., a steam flow rate of 218 g / hr, and a nitrogen flow rate of 220 NL / hr.
The proton content of the catalyst A after the steaming treatment was determined by liquid phase ion exchange / filtered droplet method, and it was 0.0014 mmol / g-zeolite.
After the steaming treatment, 60 g of catalyst A was charged into a Hastelloy C reactor having an inner diameter of 27.2 mmφ.
No. 1 of C4 raffinate-2 (obtained by extracting butadiene and isobutene from a C4 fraction obtained by steam cracking naphtha) shown in Table 1. 1 was used as a raw material, and the reaction was performed under the conditions of a reaction temperature of 550 ° C., a supply amount of C4 raffinate-2 of 450 g / hr (WHSV = 7.50 hr ⁻¹ ), and 0.1 MPaG.
The reaction product after a predetermined time from the start of the raw material supply was directly introduced into the gas chromatography (TCD, FID detector) from the reactor outlet, and the composition was analyzed.
The analysis by gas chromatograph was performed under the following conditions.

(Gas chromatograph analysis conditions)
Apparatus: GC-17A manufactured by Shimadzu Corporation
Column: Custom capillary column manufactured by SUPELCO, USA SPB-1 (inner diameter 0.25 mm, length 60 m, film thickness 3.0 μm)
Sample gas volume: 1ml (sampling line kept at 200-300 ° C)
Temperature rising program: held at 40 ° C. for 12 minutes, then heated to 200 ° C. at 5 ° C./minute, and then held at 200 ° C. for 22 minutes.
Split ratio: 200: 1
Carrier gas (nitrogen) flow rate: 120 ml / min FID detector: air supply pressure 50 kPa (about 500 ml / min), hydrogen supply pressure 60 kPa (about 50 ml / min)
Measurement method: A TCD detector and an FID detector are connected in series, hydrogen and hydrocarbons having 1 and 2 carbon atoms are detected by a TCD detector, and hydrocarbons having 3 or more carbon atoms are detected by an FID detector. 10 minutes after the start of analysis, the detection output is switched from TCD to FID.

The reaction was continued for 48 hours while appropriately analyzing the reaction product. The results are shown in Table 2.
In this example, the difference in propylene yield [PY yield (2 hours) -PY yield (48 hours)] between 2 hours and 48 hours after the start of the reaction was suppressed to only 2%.
From this example and Comparative Example 1, when the silica-alumina ratio of the zeolite-containing molded catalyst is 400, the PY yield drop is large due to coking deterioration after 2 days of operation, whereas the silica-alumina ratio is It can be seen that when 1200 zeolite is used, the decrease in propylene yield after 2 days of operation can be suppressed to only 2%. That is, when the present invention is industrially implemented in a simple fixed bed reactor two-column swing system, the catalyst of the present invention has a small change in performance when switching even in a two-day cycle (acceptable level in operation management). This suggests that a 2-day cycle operation is possible.

[Example 2]
C4 raffinate-2 no. A reaction experiment similar to that of Example 1 was performed except that 2 was used. C4 raffinate-2 no. 2 contains 2.25% by mass of diolefin compounds (methylacetylene, propadiene, butadiene).
The reaction results are shown in Table 2.
The difference in propylene yield between 2.5 hours and 48 hours after the start of the reaction was 2.56%.
From this example and Comparative Example 2, even when using a raw material having a diolefin compound concentration of 2.25% by mass, if the zeolite-containing shaped catalyst of the present invention is used, the deterioration is not adversely affected. It can be seen that continuation of operation for two days can be carried out without problems.

[Comparative Example 1]
Silica-alumina molar ratio of 407 (by completely dissolving the zeolite-containing shaped catalyst was determined by measuring by the ICP method.) A is ZSM5 type zeolite molded catalyst containing the (SiO ₂ binder 30 wt% content, 1. 6 mmφ * 5 to 10 mmL) of H exchange type was dispersed in 1N sodium nitrate aqueous solution (10 cc / g-zeolite molding), and the ion exchange treatment at room temperature for 1 hour was repeated three times. Next, filtration, washing with water and drying were performed to prepare a Na exchange type ZSM-5 / SiO ₂ molded body catalyst. This was dispersed in a 0.00145N silver nitrate aqueous solution (10 cc / g-zeolite molding) and subjected to ion exchange treatment at room temperature for 2 hours. Next, the catalyst B was prepared by filtration, washing with water and drying.
The Ag content of Catalyst B measured by fluorescent X-ray analysis was 0.094% by mass. That is, the occupancy rate (ion exchange rate) of the silver cation with respect to the zeolite exchange site (aluminum amount) was 15.3%.
Catalyst B was packed in a 27.2 mmφ Hastelloy C reactor, and steamed for 5 hours under conditions of a temperature of 650 ° C., a steam flow rate of 218 g / hr, and a nitrogen flow rate of 220 NL / hr.
The proton content of the catalyst B after the steaming treatment was determined by liquid phase ion exchange / filter drop method, and it was 0.0016 mmol / g-zeolite.
A reaction evaluation experiment was conducted in the same manner as in Example 1 except that the catalyst B after the steaming treatment was used. The results are shown in Table 3. In this comparative example, the difference in propylene yield between 2 hours and 48 hours after the start of the reaction was as large as 4.6%.

[Comparative Example 2]
C4 raffinate-2 no. A reaction experiment similar to that of Comparative Example 1 was performed except that 2 was used. The results are shown in Table 3.
In this comparative example, the difference in propylene yield between 8 hours and 48 hours after the start of the reaction was 8%, and a significant decrease in the propylene yield appeared.

[Example 3]
Silica-alumina molar ratio of 1840 (the zeolite-containing shaped catalyst is completely dissolved was determined by measuring by the ICP method.) A is ZSM5 type zeolite molded catalyst containing the (SiO ₂ binder 30 wt% content, 1. 6 mmφ * 5 to 10 mmL) of H exchange type was dispersed in 1N sodium nitrate aqueous solution (10 cc / g-zeolite molding), and the ion exchange treatment at room temperature for 1 hour was repeated three times. Next, filtration, washing with water and drying were performed to prepare a Na exchange type ZSM-5 / SiO ₂ molded body catalyst. This was dispersed in a 0.0026N silver nitrate aqueous solution (10 cc / g-zeolite molding) and subjected to ion exchange treatment at room temperature for 2 hours. Next, the catalyst C was prepared by filtration, washing with water and drying.
The Ag content of Catalyst C measured by fluorescent X-ray analysis was 0.094% by mass. That is, the silver cation occupancy (ion exchange rate) relative to the zeolite exchange site (aluminum content) was 69%.
Catalyst C was charged into a Hastelloy C reactor having an inner diameter of 27.2 mmφ, and steaming was performed for 5 hours under the conditions of a temperature of 650 ° C., a steam flow rate of 218 g / hr, and a nitrogen flow rate of 220 NL / hr.
The proton amount of the catalyst C after the steaming treatment was determined by liquid phase ion exchange / filter droplet constant method to be 0.0014 mmol / g-zeolite.
A reaction evaluation experiment was conducted in the same manner as in Example 1 except that the catalyst C after the steaming treatment was used. The results are shown in Table 2. In this example, the difference in propylene yield between 2 hours and 48 hours after the start of the reaction was suppressed to 2.2%.

[Comparative Example 3]
Silica-alumina molar ratio of 3011 (the zeolite-containing shaped catalyst is completely dissolved was determined by measuring by the ICP method.) A is ZSM5 type zeolite molded catalyst containing the (SiO ₂ binder 30 wt% content, 1. 6 mmφ * 5 to 10 mmL) of H exchange type was dispersed in 1N sodium nitrate aqueous solution (10 cc / g-zeolite molding), and the ion exchange treatment at room temperature for 1 hour was repeated three times. Next, filtration, washing with water and drying were performed to prepare a Na exchange type ZSM-5 / SiO ₂ molded body catalyst. This was dispersed in an aqueous 0.01N silver nitrate solution (10 cc / g-zeolite molding) and subjected to an ion exchange treatment at room temperature for 2 hours. Next, the catalyst D was prepared by filtration, washing with water and drying.
The amount of Ag of catalyst D measured by fluorescent X-ray analysis was 0.044% by mass. That is, the occupancy rate (ion exchange rate) of the silver cation with respect to the zeolite exchange site (aluminum amount) was 53%.
Catalyst D was filled in a Hastelloy C reactor having an inner diameter of 27.2 mmφ, and steaming was performed for 5 hours under the conditions of a temperature of 650 ° C., a steam flow rate of 218 g / hr, and a nitrogen flow rate of 220 NL / hr.
The proton amount of the catalyst D after the steaming treatment was determined by liquid phase ion exchange / filter droplet method, and it was 0.0014 mmol / g-zeolite.
A reaction evaluation experiment was conducted in the same manner as in Example 1 except that the catalyst D after the steaming treatment was used, but the reaction was stopped because the C4 olefin conversion rate in 2 hours was as low as 32%.
In the case of using the zeolite-containing molded catalyst of this comparative example, even if the silver cation occupancy with respect to the zeolite exchange site is 100%, the silver content is only 0.083% by mass, and the activity in the first place is Low things can be estimated easily. It can also be seen that, despite the fact that the exchange liquid concentration was increased as in this comparative example, the ion exchange efficiency was lowered and the silver exchange could not be carried sufficiently. It is clear that even if such a catalyst is subjected to the reaction, sufficient activity cannot be obtained.

  A method for producing ethylene and propylene by catalytic conversion from a hydrocarbon raw material, wherein a hydrocarbon raw material containing 20% by mass or more of at least one olefin having 4 to 12 carbon atoms is converted into a zeolite-containing molded catalyst in a reactor. If the zeolite-containing molded catalyst of the present invention is used in a method for producing ethylene and propylene by carrying out catalytic conversion reaction of the at least one olefin having 4 to 12 carbon atoms with It can be manufactured efficiently and stably. This is because the zeolite-containing shaped catalyst used in the method of the present invention has a very high resistance to deterioration, and can be produced with high yield and stability over a long period of time by a simple method. Moreover, even if it contains diolefin compounds in the raw material hydrocarbon mixture, it can be used for the reaction as it is within 2.5% by mass. A great load is not applied in the catalyst preparation process. These features are extremely useful in practicing the present invention industrially.

It is the graph which showed the time-dependent change of the C4 olefin conversion rate in Example 1, 2 of this invention, and Comparative example 1,2.

Claims (8)

A hydrocarbon raw material containing 20% by mass or more of at least one olefin having 4 to 12 carbon atoms is brought into contact with a zeolite-containing shaped catalyst in a reactor, so that the at least one olefin having 4 to 12 carbon atoms is produced. A method for producing ethylene and propylene by performing a catalytic conversion reaction, wherein the zeolite in the zeolite-containing shaped catalyst satisfies the following requirements (1), (2), (3) and (4) A process for producing ethylene and propylene characterized by the above.
(1) The zeolite is an intermediate pore size zeolite having a pore size of 5 to 6.5 mm.
(2) The zeolite is substantially free of protons.
(3) The zeolite contains at least one metal selected from the group consisting of metals belonging to Group IB of the Periodic Table.
(4) The silica alumina molar ratio (SiO ₂ / Al ₂ O ₃ molar ratio) of the zeolite is 800 or more and 2,000 or less.   2. The ethylene and propylene according to claim 1, wherein the hydrocarbon raw material contains at least one olefin having 4 to 12 carbon atoms in an amount of 50% by mass or more based on the weight of the hydrocarbon raw material. Manufacturing method.   The hydrocarbon raw material contains at least one diolefin compound having 3 to 12 carbon atoms in an amount of 2.5% by mass or less based on the weight of the hydrocarbon raw material. A method for producing ethylene and propylene as described in 1. above.   The production of ethylene and propylene according to any one of claims 1 to 3, wherein the zeolite in the zeolite-containing molded catalyst supports silver and an alkali metal and does not substantially contain a proton. Method.   The method for producing ethylene and propylene according to any one of claims 1 to 4, wherein the zeolite in the zeolite-containing shaped catalyst is selected from the group consisting of ZSM-5 type zeolite.   The zeolite-containing molded catalyst is heat-treated at a temperature of 500 ° C. or higher in the presence of water vapor prior to contact with the hydrocarbon raw material. Of ethylene and propylene.   The process according to any one of claims 1 to 6, characterized in that the reactor is an adiabatic fixed bed reactor. The reaction conditions for the catalytic conversion reaction are: reaction temperature: 500-580 ° C., partial pressure of hydrocarbon raw material: 0.05-0.3 MPa, weight hourly space velocity: 2-10 hr ⁻¹ , The manufacturing method of ethylene and propylene in any one of Claims 1-7.

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