WO2008062595A1 - Process for producing liquid fuel - Google Patents

Abstract

A process for producing a liquid fuel by the hydrocracking of a paraffinic hydrocarbon. The process is characterized by bringing, in the presence of hydrogen, a paraffinic hydrocarbon into contact with a catalyst which comprises a support comprising a crystalline aluminosilicate and an amorphous solid acid and, deposited on the support, at least one metal selected among the metals in Group VIII of the Periodic Table and which contains at least one element selected between phosphorus and boron.

Description

 Specification

 Method for producing liquid fuel

 Technical field

 The present invention relates to a method for producing a liquid fuel from paraffinic hydrocarbons in the presence of hydrogen.

 Background art

 [0002] In recent years, there has been a rapid increase in demand for clean liquid fuels with low sulfur and aromatic hydrocarbon content! Correspondingly, various clean fuel production methods have already been studied in the fuel oil production industry! Among them, there is great expectation for a process of hydrocracking paraffinic hydrocarbons such as wax in the presence of a catalyst.

 [0003] In the hydrocracking process of norafine hydrocarbons, it is important to improve the economics of the process by obtaining a useful middle distillate with a high activity of the catalyst used in a high yield. In addition, it is necessary that the pour point of the light oil fraction obtained is low. In other words, the development of a high-performance hydrocracking catalyst with high cracking activity, high middle distillate yield, and low gas pour point of the produced gas oil is the key to improving process economics.

 [0004] Hydrocracking using vacuum gas oil as a raw material has already been commercialized and is an established technology with a history of several decades. However, the reactivity of paraffinic hydrocarbons, especially those that contain a large amount of normal paraffins such as wax, is very different from that of vacuum gas oil, and it is difficult to divert the catalyst of vacuum gas oil as it is. R & D is currently continuing vigorously with the aim of developing catalysts. There are already a few patents. For example, Patent Document 1 discloses a catalyst in which platinum is supported on a support containing silica alumina. Further, Patent Document 2 describes a research example in which paraffinic hydrocarbons were hydrocracked using a catalyst in which platinum was supported on a support in which crystalline aluminosilicate (zeolite) and silica alumina which is an amorphous solid acid were combined. It is disclosed.

 Patent Document 1: JP-A-6-41549

 Patent Document 2: Pamphlet of International Publication No. 2004/028688

Disclosure of the invention Problems to be solved by the invention

[0005] To improve the economics of paraffinic hydrocarbon hydrocracking process,

 (1) High catalytic decomposition activity

 (2) High yield of middle distillate

 (3) The low temperature fluidity of the produced middle distillate (especially gas oil distillate) is good.

 is important. However, if the cracking activity of the catalyst is high, the middle distillate once produced is easily decomposed, and as a result, the final middle distillate yield will be low. That is, the above (1) and (2) are contrary to each other, and it is very difficult to achieve both in the conventional hydrocracking process. In addition, power and tradeoffs are a major obstacle to improving the economic efficiency of the hydrocracking process of paraffinic hydrocarbons.

[0006] The present invention has been made in view of the above circumstances, and its purpose is to improve the cracking activity of the catalyst and the yield of the middle distillate in the hydrocracking process of norafine hydrocarbons. It is an object of the present invention to provide a method for producing a liquid fuel capable of obtaining a middle distillate having a good low-temperature fluidity that can achieve both a high rate and a high level.

 Means for solving the problem

[0007] In order to solve the above-mentioned problems, the present invention is a method for producing a liquid fuel by hydrocracking a norafine hydrocarbon, comprising crystalline aluminosilicate and an amorphous solid acid in the presence of hydrogen. And a catalyst comprising at least one metal selected from Group VIII metals of the periodic table supported on the support, and containing at least one element selected from phosphorus and boron, Provided is a method for producing a liquid fuel characterized by contacting with a laffine hydrocarbon.

 [0008] Thus, as a hydrocracking catalyst, at least one metal selected from a carrier containing crystalline aluminosilicate and an amorphous solid acid and a Group VIII metal of the periodic table carried on the carrier. And a catalyst containing at least one element selected from phosphorus and boron, the cracking activity of the catalyst and the yield of middle distillate can be compatible at a high level, and Thus, it is possible to obtain a middle distillate having good low-temperature fluidity.

[0009] The "middle distillate" referred to in the present invention is a hydrocracked product having a boiling range of 145 to 145. Means petroleum or synthetic fractions at 360 ° C. A typical example of the middle distillate is a middle distillate produced by Fisher's Tropsch ( _FT ) synthesis. The light oil fraction means a fraction having a boiling point of 260 to 360 ° C, which is a part of the middle fraction.

In the present invention, the paraffinic hydrocarbon preferably contains 70% by mass or more normal paraffin. Here, the content of normal paraffin is determined by gas chromatography method!

[0011] In the present invention, it is preferable that the crystalline aluminosilicate is an ultra-stabilized Y-type zeolite.

 [0012] When the catalyst contains phosphorus, the phosphorus content is preferably 0.2 to 5.0% by mass in terms of elements, based on the total mass of the catalyst.

[0013] When the catalyst contains boron, the boron content is preferably 0.5 to 4.0% by mass in terms of elements based on the total mass of the catalyst.

[0014] The metal supported on the carrier in the catalyst is preferably at least one selected from palladium and platinum.

 The invention's effect

 [0015] As described above, according to the method for producing a liquid fuel of the present invention, the catalyst cracking activity and the yield of middle distillate can be achieved at a high level, and good low-temperature fluidity is achieved. Middle distillate can be obtained.

 Brief Description of Drawings

FIG. 1 is an explanatory diagram showing an example of a fixed bed reactor used in the present invention.

 Explanation of symbols

 [0017] 1 · · · reaction tower, 2 · · · hydrocracking catalyst layer, 3 · · · distillation apparatus.

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described in detail.

FIG. 1 is an explanatory view showing an example of a fixed bed reactor preferably used in the present invention. In the fixed bed reactor shown in FIG. 1, a hydrocracking catalyst layer 2 is provided in the reaction tower 1. The top of the reaction tower 1 is used for supplying hydrogen into the reaction tower 1. Line LI is connected, and line L2 for supplying paraffinic hydrocarbons as a raw material is connected upstream of the connection part of line LI with reaction tower 1. On the other hand, the bottom of the reaction tower 1 is connected to a line L3 for extracting the decomposition product after hydrocracking from the reaction tower 1, and the other end of the line L3 is connected to a distillation apparatus 3 at atmospheric pressure. Yes.

 [0020] As the paraffinic hydrocarbon as a raw material, a hydrocarbon having a normal paraffin molecule content of 70% by mass or more is preferable. The carbon number distribution of the norafin hydrocarbon is not particularly limited, but a hydrocarbon having a carbon number of 18 or more that is solid at room temperature, that is, a paraffin hydrocarbon usually referred to as nitrogen can be used.

 [0021] The process for producing the paraffinic hydrocarbon as a raw material is not particularly limited, and the present invention has a power that can be applied to various petroleum-based and synthetic paraffinic hydrocarbons. As a particularly preferable paraffinic hydrocarbon, Manufactured by Fischer-Tropsch synthesis!

 [0022] The hydrocracking catalyst layer 2 includes a support containing crystalline aluminosilicate and an amorphous solid acid, and at least one metal selected from Group VIII metals of the periodic table supported on the support. And / or a catalyst containing at least one element selected from phosphorus and boron!

 [0023] The "aluminosilicate" in the present invention means a metal oxide mainly composed of three elements of aluminum, silicon, and oxygen, but is within the range not hindering the effect of the present invention. It may contain a metal element. Examples of the metal element that can coexist include titanium, lanthanum, manganese, gallium, and zinc, with titanium and lanthanum being preferred. The amount of other metal elements is preferably 5% by mass or less, more preferably 3% by mass or less, with respect to the total amount (the total amount of alumina and silica) when aluminum and silicon are converted into their oxides. It is.

[0024] The crystallinity of aluminosilicate can be estimated by the ratio of tetracoordinate aluminum atoms in all aluminum atoms, and this ratio can be measured by ²⁷ A1 solid state NMR. The “crystalline aluminosilicate” in the present invention means an aluminosilicate having a tetracoordinate aluminum ratio of 70% or more. If the proportion of tetracoordinated aluminum is 70% or more, there is no particular limitation on the crystalline aluminosilicate used. The ratio is preferably 80% or more, more preferably 85% or more.

 [0025] As the crystalline aluminosilicate, so-called zeolite can be used. Preferred crystalline aluminosilicates include Y-type zeolite, ultra-stabilized Y-type zeolite (US Y-type zeolite), beta-type zeolite, mordenite, etc. Among them, U SY-type zeolite is particularly preferred. Further, crystalline aluminosilicates may be used alone or in combination of two or more.

 [0026] The average particle size of the crystalline aluminosilicate is not particularly limited, but preferably 1.

 It is 0 μm or less, more preferably 0.5 111 or less. If the particle size of the crystalline aluminosilicate is 1.0 m or less, the yield of middle distillate tends to be further improved.

 [0027] The content of the crystalline aluminosilicate in the catalyst is not particularly limited, but is preferably 0.;! To 8.0% by mass based on the total mass of the catalyst.

 [0028] Further, examples of the amorphous solid acid include silica alumina, silica zirconia, silica titania, silica magnesia, alumina zirconia, and alumina polyaer. Among these, alumina polya is preferably used.

 [0029] The content of the amorphous solid acid in the catalyst is not particularly limited, but is preferably 5 to 70% by mass based on the total mass of the catalyst.

 [0030] The carrier containing the crystalline aluminosilicate and the amorphous solid acid can be molded without using a binder. Usually, a binder can be used. The binder used in that case is not particularly limited, but alumina and silica can be used, and alumina is most preferable. The amount of the binder used is not particularly limited, but is preferably 20 to 90% by mass, more preferably 40 to 80% by mass, based on the total mass of the carrier. By setting the amount of binder used within the range of 20 to 90% by mass, a catalyst having sufficient strength can be obtained effectively.

 [0031] The catalyst constituting the hydrocracking catalyst layer 2 contains at least one element selected from phosphorus and boron.

[0032] When the catalyst contains a phosphorus content of phosphorus, based on the total weight of the catalyst, in Genso換calculation, preferably 0.1;! ~ 8.0 mass _^0/0, more preferably 0. 2-5. 0 weight _^0/0. If the phosphorus content is less than 0.1% by mass, the effect of improving the decomposition activity tends to be insufficient. Also, Even if the phosphorus content exceeds 8.0% by mass, there is a tendency that a further effect of improving the decomposition activity commensurate with the content cannot be obtained. The phosphorus content in the catalyst can be measured by a measuring means such as inductively coupled plasma atomic emission spectrometry.

[0033] Also, when the catalyst contains boron, the proportion of boron, based on the total weight of the catalyst, in terms of element, preferably 0.3 to 8.0 mass _^0/0, more preferably 0.5 ~ 4.0% by mass. If the boron content is less than 0.3% by mass, the effect of improving the decomposition activity tends to be insufficient. Further, even if the boron content exceeds 8.0% by mass, there is a tendency that a further decomposition activity improvement effect corresponding to the content cannot be obtained, and further, the strength of the catalyst tends to be lowered. The boron content in the catalyst can be measured by measuring means such as inductively coupled plasma atomic emission spectrometry.

 [0034] Examples of the method for introducing phosphorus into the catalyst include phosphorus-containing compounds such as phosphoric acid and phosphorus pentoxide in a binder before firing (when the binder is alumina, the state of boehmite is the same hereinafter). The method of adding is mentioned. Examples of the method of introducing boron into the catalyst include a method of adding a boron-containing compound such as boric acid to the binder before firing. When the crystalline aluminosilicate or the amorphous solid acid contains phosphorus or boron as in the case of using alumina polya as the amorphous solid acid, the above-described method for introducing phosphorus or boron is not necessarily adopted. However, the above-described method for introducing phosphorus or boron is useful for adjusting the phosphorus or boron content in the catalyst.

 [0035] At least one metal selected from Group VIII metals of the periodic table is supported as an active component on the above-described carrier (in the case of molding using a binder). Specific examples of the Group VIII metal include cobalt, Eckenole, rhodium, palladium, iridium, platinum, etc. Among these, palladium and platinum are preferable. If a metal other than Group VIII metal of the periodic table is used as the active component of the catalyst, the yield of middle distillate will be significantly reduced.

[0036] As the Group VIII metal to be supported, one kind may be used alone, or two or more kinds may be used in combination. For example, it is possible to use both platinum and palladium. The amount of Group VIII metal supported is not particularly limited, but is based on the total mass of the catalyst. Preferably, the content is 0.02 to 2% by mass. Examples of the method of supporting the Group VIII metal carrier (molded with a binder! /, In that case, the molded body) include a method of supporting the carrier or molded body by conventional methods such as impregnation and ion exchange. It is done.

[0037] For the hydrocracking catalyst layer 2 composed of the above catalyst, it is preferable to perform metal reduction in a reducing gas atmosphere such as hydrogen before hydrocracking. The reduction conditions are not particularly limited, but the reduction temperature is preferably 300 to 360 ° C., and the reduction time is preferably 1 to 6 hours.

[0038] As the reaction conditions for hydrocracking in the reaction tower 1, the temperature is 200 to 450 ° C, the hydrogen pressure is 0.5 to 12 MPa, and the liquid space velocity of the paraffinic hydrocarbon raw material is 0. ; ~ 101T ¹ can increase the force S, preferably 250 ~ 380 ° C, hydrogen pressure is 2.0 ~ 8MPa, liquid space velocity of paraffinic hydrocarbon feedstock is 0.3 ~ 5. Oh— ¹ .

 [0039] The distillation apparatus 3 is capable of fractionating a hydrocracked decomposition product according to the distillation properties. For example, the decomposition products include middle distillate with a boiling point of 145-360 ° C, light distillate with a boiling point of less than 145 ° C (such as naphtha distillate), and wax fraction with a boiling point of over 360 ° C. These can be separated by the distillation apparatus 3. In addition, for example, the middle distillate may include a kerosene distillate (a distillate having a boiling point of 145 to 260 ° C.) in addition to the light oil distillate. The fractionated fractions are transferred to subsequent processes by lines (L4 to L7) connected to the distillation apparatus 3.

 [0040] According to the above embodiment, the catalyst constituting the hydrocracking catalyst layer 2 includes a carrier containing crystalline aluminosilicate and an amorphous solid acid, and a periodic table Group VIII metal supported on the carrier. By using a catalyst comprising at least one selected metal and containing at least one element selected from phosphorus and boron, a high level of cracking activity and middle distillate yield Therefore, it is possible to obtain a middle distillate having good low-temperature fluidity.

Note that the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the hydrocracking catalyst layer 2 may have a single layer structure! /, And different types of hydrocracking catalyst layers may be stacked to form a multilayer structure. In addition, if the decomposition products contain unreacted paraffinic hydrocarbons, a transfer line connecting the distillation unit 3 and the top of the reaction tower 1 is provided. Alternatively, the unreacted wax fraction separated by the distillation apparatus 3 may be introduced into the reaction tower 1 through a transfer line and again subjected to hydrocracking (bottom recycling). In addition, a fixed bed reactor is exemplified as an apparatus for hydrocracking paraffinic hydrocarbons, but is not particularly limited as long as it can contact the raw material wax and the hydrocracking catalyst. A bed reactor may be used.

 Example

 [0042] Hereinafter, the present invention will be more specifically described based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

 [0043] (Preparation of catalyst A)

USY zeolite with an average particle diameter of 0.5 m (silica / alumina ratio (molar ratio): 37) 30 g, silica alumina (alumina content: 14% by mass) 500 _§ , phosphorus-containing bermite (using phosphoric acid) 400 g), and the mixture is used to form a cylindrical molded body with a diameter of 1/16 inch (about 1.6 mm). Was made. The obtained molded body was fired in air at 500 ° C. for 1 hour to obtain a carrier.

 [0044] Next, the resulting support was impregnated with an aqueous solution of dichlorotetraammineplatinum (II) and heated at 120 ° C.

 After drying for 3 hours, it was calcined at 500 ° C. for 1 hour to obtain catalyst A (phosphorus content: 1.8% by mass, platinum loading: 0.5% by mass).

 [0045] (Preparation of catalyst B)

USY zeolite with an average particle size of 0.5 m (silica / alumina ratio (molar ratio): 37) 30 g, silica alumina (alumina content: 14% by mass) 500 _§ , boron-containing bermite (boric acid used) (Boronite is prepared so that the boron content in the boehmite becomes 10.0% by mass) 400 g is mixed, and the mixture is used to form a cylindrical molded body having a diameter of 1/16 inch (about 1.6 mm). Was made. The obtained molded body was fired in air at 500 ° C. for 1 hour to obtain a carrier.

 [0046] Next, the obtained support was impregnated with an aqueous solution of dichlorotetraammineplatinum (II) at 120 ° C.

 After drying for 3 hours, the mixture was calcined at 500 ° C. for 1 hour to obtain catalyst B (boron content: 3.7 mass%, platinum loading: 0.5 mass%).

 [0047] (Preparation of catalyst C)

USY zeolite with an average particle size of 0.5 m (silica / alumina ratio (molar ratio): 37) 30 g, Silica-alumina (alumina content: 14% by mass) 500 _§ and phosphorus and boron-containing monomite (using phosphoric acid so that the phosphorus content in boehmite is 4.0% by mass (Boronite was prepared so that the boron content in boehmite was 6.0% by mass.) 4 OOg was mixed, and the mixture was used to form a cylindrical shape with a diameter of 1/16 inch (about 1.6 mm) A molded body was produced. The obtained molded body was fired in air at 500 ° C. for 1 hour to obtain a carrier.

 [0048] Next, the resulting support was impregnated with an aqueous solution of dichlorotetraammineplatinum (II) and heated at 120 ° C.

 After drying for 3 hours, calcining for 1 hour at 500 ° C, catalyst C (phosphorus content: 1.2 mass%, boron content: 2.1 mass%, platinum loading: 0.5 mass%) Got.

 [0049] (Preparation of catalyst D)

USY zeolite with an average particle size of 0 · 8 m (silica / alumina ratio (molar ratio): 32) 30 g, silica zircoyu (zirconia content: 30% by mass) 500 _§ , phosphorus-containing baseite (phosphoric acid) (Used so that the phosphorous content in boehmite is 5.0% by mass.) 400 g is mixed, and the mixture is used to produce a cylindrical molded body with a diameter of 1/16 inch (about 1.6 mm). did . The obtained molded body was fired in air at 500 ° C. for 1 hour to obtain a carrier.

 [0050] Next, the resulting support was impregnated with an aqueous solution of dichlorotetraammineplatinum (II) and heated at 120 ° C.

 After drying for 3 hours, it was calcined at 500 ° C. for 1 hour to obtain catalyst D (phosphorus content: 1.8% by mass, platinum loading: 0.5% by mass).

 [0051] (Preparation of catalyst E)

 A catalyst was prepared in the same manner as Catalyst A, except that phosphorus-free bermite was used, and Catalyst E (platinum supported amount: 0.5 mass%) was obtained.

 [0052] (Preparation of catalyst F)

 A catalyst was prepared in the same manner as Catalyst D, except that phosphorus-free bermite was used, and Catalyst F (platinum supported amount: 0.5 mass%) was obtained.

 [0053] (Example 1)

Catalyst A (100 ml) was charged into a fixed bed flow reactor and hydrocracked paraffinic hydrocarbons. In this example, FT wax having a normal paraffin content of 96% by mass, a carbon number distribution of 20 to 80 was used as a raw material, the hydrogen pressure was 4 MPa, and the liquid space velocity of the raw material was 2. Oh- ¹ . And 80% by mass decomposition product (boiling point 360 ° C or less) The same shall apply hereinafter. ) And the yield of the middle distillate with respect to the raw material at that reaction temperature (the fraction with a boiling point of 145 to 360 ° C) and the resulting gas oil (the fraction with a boiling point of 260 to 360 ° C) The pour point of was determined. The results obtained are shown in Table 1.

[0054] (Example 2)

 Reaction in which hydrocracking of paraffinic hydrocarbons was performed in the same manner as in Example 1 except that catalyst B was used instead of catalyst A, and a cracked product of 80% by mass was obtained with respect to the raw material. The temperature, the yield of the middle distillate relative to the raw material at the reaction temperature, and the pour point of the produced gas oil were determined. The results obtained are shown in Table 1.

[Example 3]

 Reaction in which hydrocracking of paraffinic hydrocarbons was performed in the same manner as in Example 1 except that catalyst C was used instead of catalyst A, and a cracked product of 80% by mass with respect to the raw material was obtained. The temperature, the yield of the middle distillate relative to the raw material at the reaction temperature, and the pour point of the produced gas oil were determined. The results obtained are shown in Table 1.

[0056] (Example 4)

 Reaction in which hydrocracking of paraffinic hydrocarbons was carried out in the same manner as in Example 1 except that catalyst D was used instead of catalyst A, and a cracked product of 80% by mass with respect to the raw material was obtained. The temperature, the yield of the middle distillate relative to the raw material at the reaction temperature, and the pour point of the produced gas oil were determined. The results obtained are shown in Table 1.

[0057] (Comparative Example 1)

 Reaction in which hydrocracking of paraffinic hydrocarbons is performed in the same manner as in Example 1 except that catalyst E is used instead of catalyst A, and a cracked product of 80% by mass is obtained with respect to the raw material. The temperature, the yield of the middle distillate relative to the raw material at the reaction temperature, and the pour point of the produced gas oil were determined. The results obtained are shown in Table 1.

[0058] (Comparative Example 2)

Reaction in which hydrocracking of paraffinic hydrocarbons is performed in the same manner as in Example 1 except that catalyst F is used instead of catalyst A, and a cracked product of 80% by mass is obtained with respect to the raw material The temperature, the yield of the middle distillate relative to the raw material at the reaction temperature, and the pour point of the produced gas oil were determined. The results obtained are shown in Table 1. ] Decomposition temperature Yield of middle distillate Pour point of produced gas oil

(.C) (mass%) (.c) Example 1 293 57.1 -25.0 Example 2 296 56.6 -22.5 Example 3 291 57.3 -22.5 Example 4 299 56.8 -25.0 Comparative Example 1 300 54.8 -22.5 Comparative Example 2 306 54.5 -22.5

Claims

The scope of the claims  [1] A method for producing liquid fuel by hydrocracking paraffinic hydrocarbons, in the presence of hydrogen,  A support containing a crystalline aluminosilicate and an amorphous solid acid; and at least one metal selected from Group VIII metals of the periodic table supported by the support; and at least one selected from phosphorus and boron A catalyst containing the elements of:  With paraffinic hydrocarbons  A method for producing a liquid fuel, characterized in that  [2] The method for producing a liquid fuel according to [1], wherein the paraffinic hydrocarbon contains 70% by mass or more of normal paraffin. [3] The method for producing a liquid fuel according to claim 1 or 2, wherein the crystalline aluminosilicate is ultra-stabilized Y-type zeolite. [4] The content of phosphorus in the catalyst is 0.2 to 5.0% by mass in terms of element conversion based on the total mass of the catalyst. The method for producing a liquid fuel as described in 1 above. [5] The content of the boron in the catalyst is 0.5 to 4.0% by mass in terms of elements based on the total mass of the catalyst. The method for producing a liquid fuel as described in 1 above. 6. The method for producing a liquid fuel according to any one of claims 1 to 5, wherein the metal is at least one selected from palladium and platinum.