WO2007102397A1

WO2007102397A1 - Method of wax hydrocracking

Info

Publication number: WO2007102397A1
Application number: PCT/JP2007/053931
Authority: WO
Inventors: Hiroyuki Seki; Hirofumi Konno
Original assignee: Nippon Oil Corporation
Priority date: 2006-03-06
Filing date: 2007-03-01
Publication date: 2007-09-13
Also published as: MY147196A; JP2007238672A; AU2007223508A1; RU2428457C2; AU2007223508B2; RU2008139409A; JP4773232B2; CN101395253B; CN101395253A

Abstract

A method of wax hydrocracking, characterized by disposing in a fixed-bed reactor a first hydrocracking catalyst layer and a second hydrocracking catalyst layer respectively on the upstream side and downstream side in the reactor so as to satisfy the requirement represented by the following relationship (1), passing hydrogen and a wax through the first hydrocracking catalyst layer, additionally adding hydrogen to a decomposition product from the first hydrocracking catalyst layer upstream from the upstream end of the second hydrocracking catalyst layer, and passing a mixture comprising the decomposition product and the hydrogen additionally added through the second hydrocracking catalyst layer. d1/(d1+d2)≥1/3 (1) [In the relationship (1), d1 indicates the distance between the upstream end and downstream end of the first hydrocracking catalyst layer; and d2 indicates the distance between the upstream end and downstream end of the second hydrocracking catalyst layer.]

Description

Specification

Method for hydrocracking wax

Technical field

[0001] The present invention relates to a method for hydrocracking wax.

Background art

[0002] In recent years, from the standpoint of environmental protection, regulations on sulfur content in liquid fuels such as gasoline and light oil are rapidly becoming stricter. For this reason, there is a high expectation for clean liquid fuels with low sulfur content and aromatic hydrocarbon content.

[0003] As one of the methods for producing such clean fuel, there is a Fischer-Tropsch (FT) synthesis method using natural monoxide carbon and hydrogen as raw materials, which can be obtained by reforming natural gas! In addition, the so-called gas-to-liquid (GTL) synthesis method, such as the method of hydrocracking wax produced by FT synthesis (FT wax), is in the limelight. The fuel base material obtained by the FT synthesis method has normal paraffin as the main component, so there is a limit to using it as gasoline or light oil as it is. The fuel base material obtained by hydrocracking FT wax is isoparaffin. There are rich features. GTL usually aims to produce middle distillates (fuel bases such as kerosene and light oil).

[0004] Techniques for producing a fuel base material by hydrocracking wax have been studied so far. For example, Patent Documents 1 to 3 listed below include hydrocracking methods using a specific hydrocracking catalyst. Are listed.

Patent Document 1: International Publication No. 2004Z028688 Pamphlet

Patent Document 2: Japanese Patent Application Laid-Open No. 2004-255241

Patent Document 3: Japanese Patent Laid-Open No. 2004-255242

Disclosure of the invention

Problems to be solved by the invention

[0005] However, in the conventional wax hydrocracking method, as described in Patent Documents 1 to 3 above, the development of a high-performance hydrocracking catalyst is the center, and the process is improved. There is no report on the improvement of the yield of the fuel base material. Also, the process From the viewpoint of safety, it is important to reduce the consumption of hydrogen used in hydrocracking, but it is difficult to say that sufficient consideration has been made for this viewpoint.

[0006] The present invention has been made in view of such circumstances, and is a wax that can sufficiently improve the yield of middle distillate and can sufficiently reduce the consumption of hydrogen. The object is to provide a hydrocracking method.

Means for solving the problem

[0007] In order to solve the above-described problem, the wax hydrocracking method of the present invention includes a first hydrocracking catalyst layer on the upstream side of a fixed bed reactor and a second hydrocracking catalyst on the downstream side. The layers are provided so as to satisfy the conditions represented by the following formula (1), hydrogen and wax are circulated through the first hydrocracking catalyst layer, and upstream from the upstream end of the second hydrocracking catalyst layer. On the side, hydrogen is additionally added to the cracked product of the first hydrocracking catalyst layer, and the mixture containing the cracked product and the added hydrogen is circulated to the second hydrocracking catalyst layer. It is characterized by this.

d / (d + d) ≥1 / 3 (1)

1 1 2

[In the formula (1), d represents the upstream end force of the first hydrocracking catalyst layer and the distance to the downstream end, and d represents the downstream end of the second hydrocracking catalyst layer. Indicates the distance to. ]

2

[0008] According to the wax hydrocracking method of the present invention, the first and second hydrocracking catalyst layers are separated from their upstream end to downstream end (that is, thickness along the flow direction) d, d

1 2 is provided so as to satisfy the condition expressed by the above formula (1), and separately from the supply of hydrogen to the first hydrocracking catalyst layer, from the first hydrocracking catalyst layer at the specified position. By additionally adding hydrogen to the cracked product, the yield of the middle distillate contained in the cracked product of the second hydrocracking catalyst layer can be sufficiently improved. In addition, compared to the case where hydrogen is supplied only to the first hydrocracking catalyst layer, the amount of hydrogen consumed in the first and second hydrocracking catalyst layers can be sufficiently reduced.

[0009] It should be noted that the decomposition product from the first hydrocracking catalyst layer may contain unreacted hydrogen. The force added to the cracked product upstream from the upstream end of the second hydrocracking catalyst layer. The added hydrogen is distinguished from the unreacted hydrogen.

[0010] In the present invention, the first hydrocracking catalyst layer has a first upstream side of the upstream end of the second hydrocracking catalyst layer. The amount of hydrogen added to the cracked product of the hydrocracking catalyst layer is preferably 5% by volume or more with respect to the amount of hydrogen supplied to the first hydrocracking catalyst layer.

In the present invention, the wax used as a raw material is preferably a wax obtained by Fischer-Tropsch synthesis.

[0012] Further, in the present invention, it is preferable that the first and second hydrocracking catalyst layers each contain ultrastable Y-type zeolite (USY zeolite).

The invention's effect

As described above, according to the wax hydrocracking method of the present invention, the yield of middle distillate can be sufficiently improved, and the consumption of hydrogen can be sufficiently reduced. become.

Brief Description of Drawings

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

FIG. 2 is an explanatory view showing another example of a fixed bed reactor used in the present invention.

Explanation of symbols

[0015] la, lb, lc ... reaction tower, 2a, 2b ... hydrocracking catalyst layer.

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 a preferred example of a fixed bed reactor used in the first embodiment of the present invention. In the fixed bed reactor shown in FIG. 1, two reaction towers la and lb are connected in series via a transfer line L3. The hydrocracking catalyst layers 2a and 2b are provided inside the reaction towers la and lb so as to satisfy the condition represented by the following formula (1). If the reaction towers la and lb have the same shape, adjust d and d by adjusting the filling amount of each hydrocracking catalyst constituting the hydrocracking catalyst layers 2a and 2b.

1 2 Can be

d / (d + d) ≥1 / 3 (1)

1 1 2

[In Formula (1), d indicates the distance from the upstream end of the hydrocracking catalyst layer 2a to the downstream end.

1 2 Indicates the distance from the upstream end of the hydrocracking catalyst layer 2b to the downstream end. ] [0018] In addition, d / (d + d) in the above formula (1) is 1Z3 to-from the ability to achieve higher yield of middle distillate and reduction of hydrogen consumption at a higher level. 5Z6 is preferred 7

1 1 2

More preferably, it is Z12-9Z12.

[0019] The hydrocracking catalyst constituting the hydrocracking catalyst layer 2a and the catalyst constituting the hydrocracking catalyst layer 2b may be the same as or different from each other.

[0020] The hydrocracking catalyst constituting the hydrocracking catalyst layers 2a and 2b is not particularly limited as long as it has hydrogenation resolution, but as a carrier thereof, silica alumina, silica zirconium, alumina boria, silica magnesia can be used. It is preferable to contain an amorphous solid acid such as USY zeolite, mordenite, j8 zeolite, ZSM-22, SAPO-11, etc., and it is particularly preferable to contain USY zeolite.

[0021] When the hydrocracking catalyst support includes USY zeolite, the proportion of USY zeolite in the support is not particularly limited. However, from the viewpoint of suppressing lightness of the fuel base, USY zeolite The ratio is preferably 15% by mass or less, more preferably 5% by mass or less, based on the total amount of the carrier.

[0022] The molar ratio of silica Z alumina in USY zeolite is not particularly limited, but is preferably 30 to 200, more preferably 30 to 100, and most preferably 30 to 60. The average particle size of U SY zeolite is preferably 1.0 μm or less, more preferably 0.5 m or less. When the average particle size of USY zeolite is larger than the upper limit, the resulting fuel base material tends to be light.

[0023] The hydrocracking catalyst may further contain a binder for molding a carrier! The binder is not particularly limited, but preferably the binder is alumina or silica. The shape of the carrier is not particularly limited, and can be granular, cylindrical (pellet) or the like.

[0024] The hydrocracking catalyst is preferably a catalyst in which a metal of Group VIII of the periodic table is supported on the above support. Specific examples of the Group VIII metal include cobalt, nickel, rhodium, palladium, iridium, and platinum. Of these, one or more selected from palladium and platinum power are preferred. Particularly, when slack wax containing oil is used as a raw material, it is preferred to support both noradium and platinum on a carrier. Yes. The amount of metal supported on the carrier is not particularly limited, but is preferably 0.01 to 2% by mass with respect to the carrier.

[0025] A line L1 for supplying hydrogen into the reaction tower la is connected to the top of the reaction tower la, and wax is supplied to the upstream side of the connection portion of the line L1 with the reaction tower. Line L2 is connected. As a result, it is possible to introduce the wax together with hydrogen into the reaction tower la and perform hydrocracking through the hydrocracking catalyst layer 2.

[0026] Examples of the wax to be subjected to hydrocracking include petroleum or synthetic waxes containing 30% by mass or more of normal paraffins having 16 or more carbon atoms, preferably 20 or more carbon atoms. Examples of petroleum waxes include slack wax and micro wax, and examples of synthetic waxes include so-called FT wax produced by FT synthesis.

[0027] Although FIG. 1 shows an example of a reactor in which the hydrogen supply line L1 and the wax supply line L2 are joined, the hydrogen supply line L1 and the wax supply line L2 are separately connected to the reaction tower la. It may be connected. Further, the flow direction of the wax is preferably a direction in which the top side force of the reaction tower la is directed toward the bottom side as shown in FIG.

[0028] Conditions for the hydrocracking of wax in the reaction tower la are not particularly limited, but the reaction temperature is preferably 250 to 370 ° C. If the reaction temperature exceeds 370 ° C, aromatic compounds are likely to be produced, which is not preferable from the viewpoint of obtaining a clean fuel substrate. The reaction pressure (hydrogen partial pressure) is preferably 1 to 12 MPa, more preferably 2 to 6 MPa. If the reaction pressure is less than the above lower limit, the hydrocracking catalyst tends to deteriorate, and if the reaction pressure exceeds the upper limit, the reaction temperature for obtaining the same decomposition rate tends to increase. The liquid space velocity is not particularly limited, but is preferably ^0.1 to ^{3. Oh_1} . The ratio of the total amount of hydrogen to be supplied and the oil (hydrogen Z oil ratio) is not particularly limited, but is preferably 100 to 850 NLZL, more preferably 200 to 650 NLZL.

[0029] The decomposition product obtained by hydrocracking in the reaction tower la is sent to the reaction tower lb through the transfer line L3. At this time, hydrogen from the hydrogen supply line L4 connected to the transfer line L3 is additionally added to the decomposition product.

[0030] Since the amount of hydrogen added to the cracked product from the hydrogen supply line L4 can further improve the yield of middle distillate obtained after hydrocracking in the reaction tower lb, the hydrogen supply line L It is preferably 5% by volume or more based on the amount of hydrogen supplied to the one-force reaction column la.

FIG. 1 shows an example of an apparatus in which a hydrogen supply line L4 is connected to a transfer line L3. The connection position of the hydrogen supply line L4 is the downstream end of the hydrocracking catalyst layer 2a and the hydrocracking catalyst layer. For example, you can connect the hydrogen supply line L4 to the top of the reaction tower lb and add hydrogen to the upstream end of 2b!

[0032] The hydrocracking of the cracked product to which hydrogen has been added in this manner is further performed by circulating the hydrocracking catalyst layer 2b of the reaction tower lb. Since the hydrocracking conditions in the reaction tower lb are the same as the hydrocracking conditions in the reaction tower la, a duplicate description is omitted here. The hydrogenation conditions in the reaction column la and the reaction column lb may be the same or different! /.

[0033] According to the first embodiment, the hydrocracking catalyst layers 2a, 2b are separated from the upstream end to the downstream end (that is, the thickness along the flow direction) d, d is expressed by the above formula (1 )

1 2

In addition to the supply of hydrogen from the hydrogen supply line L1 to the hydrocracking catalyst layer 2a, the hydrogenation line L4 generates hydrogen from the hydrogen supply line L4. By additionally adding, the yield of the middle distillate contained in the cracked product from the hydrocracking catalyst layer 2b can be sufficiently improved. In addition, the total hydrogen consumption in the hydrocracking catalyst layers 2a and 2b was sufficiently reduced compared to the case where only hydrogen was supplied from the hydrogen supply line L1 to the hydrocracking catalyst layer 2a. It becomes. The obtained decomposition products usually include naphtha (fraction with a boiling point of less than 145 ° C) and wax (fraction with a boiling point of more than 360 ° C) in addition to the middle distillate. By removing the product from the line L5 connected to the bottom of the reaction tower lb and performing distillation or the like, the fraction can be separated to obtain a substrate suitable for various applications.

FIG. 2 is an explanatory view showing a preferred example of a fixed bed reactor according to the second embodiment of the present invention. In the fixed bed reaction apparatus shown in FIG. 2, the hydrocracking catalyst layers 2a and 2b are provided in the reaction column lc so as to satisfy the condition represented by the above formula (1).

[0035] A line L1 for supplying hydrogen into the reaction column lc is connected to the top of the reaction column lc, and wax is supplied to the upstream side of the connection with the reaction column in the line L1. The line L2 is connected. As a result, the wax is introduced into the reaction column lc together with hydrogen, The hydrocracking of the wax can be carried out through the hydrocracking catalyst layers 2a and 2b in this order.

[0036] Further, a gap is provided between the downstream end of the hydrocracking catalyst layer 2a and the upstream end of the hydrocracking catalyst layer 2b, and is located at a position corresponding to the above-described gap on the side of the reaction tower lc. Is connected to the hydrogen supply line L4. As a result, hydrogen is added to the cracked product from the hydrocracking catalyst layer 2a, and the mixture of the cracked product and the added hydrogen is passed through the hydrocracking catalyst layer 2b for hydrocracking. It is possible.

[0037] In the present embodiment, the hydrocracking catalyst constituting the hydrocracking catalyst layers 2a and 2b is the same as the hydrocracking catalyst in the first embodiment, and therefore, a duplicate description is given here. Omitted. In addition, when the reaction column lc has a shape in which the cross-sectional area when the catalyst packed region is cut along a plane perpendicular to the flow direction is constant regardless of the cutting position (for example, a cylindrical shape), hydrocracking D and d can be adjusted by adjusting the filling amount of each hydrocracking catalyst constituting the catalyst layers 2a and 2b.

1 2

[0038] Further, the hydrocracking conditions in the reaction tower lc can be the same as the hydrocracking conditions in the reaction towers la and lb in the first embodiment.

[0039] According to the second embodiment, the hydrocracking catalyst layers 2a and 2b are separated from the upstream end to the downstream end (that is, the thickness along the flow direction) d and d are expressed by the above formula (1 )

1 2

In addition to the supply of hydrogen from the hydrogen supply line L1 to the hydrocracking catalyst layer 2a, the hydrogenation line L4 generates hydrogen from the hydrogen supply line L4. By additionally adding, the yield of the middle distillate contained in the cracked product from the hydrocracking catalyst layer 2b can be sufficiently improved. In addition, the total hydrogen consumption in the hydrocracking catalyst layers 2a and 2b was sufficiently reduced compared to the case where only hydrogen was supplied from the hydrogen supply line L1 to the hydrocracking catalyst layer 2a. It becomes. In addition to the middle distillate, the obtained decomposition products usually include naphtha (fraction with a boiling point of less than 145 ° C) and wax (fraction with a boiling point of more than 360 ° C). By removing the product from the line L5 connected to the bottom of the reaction tower lb and performing distillation or the like, the fraction can be separated to obtain a substrate suitable for various applications.

Example [0040] Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1]

Using silica alumina (molar ratio of silica Z alumina: 6.2) and an alumina binder, a cylindrical support with a diameter of about 1.5 mm and a length of 3 mm was formed (silica alumina Z alumina binder = 80: 20 (Mass ratio)). This carrier was impregnated with an aqueous solution of chloroplatinic acid, and 0.8% by mass of platinum was supported on the carrier. This was dried and calcined to obtain a hydrocracking catalyst.

[0042] Next, the obtained hydrocracking catalyst was filled in the reaction towers la and lb of the fixed bed reactor having the configuration shown in Fig. 1 to form hydrocracking catalyst layers 2a and 2b. In this example, the reaction towers la and lb are of the same shape with a cylindrical catalyst packing region, and the hydrocracking catalyst charge is 60 ml for reaction tower la and 90 ml for reaction tower lb. Therefore, d Z (d + d) in the above formula (1) was set to 1Z3. Hydrocracking catalyst for reaction tower la and lb

1 1 2

Each hydrocracking catalyst composing layers 2a and 2b was subjected to reduction treatment at 345 ° C for 4 hours under a hydrogen stream before the start of hydrocracking to activate the catalyst.

[0043] Next, wax hydrocracking was performed using the above fixed bed reactor. As the raw material Wakku scan FT wax (number of carbons: 21 to 80, the content of normal paraffins: 95 mass ^_0/0) were used. During the hydrocracking of wax, the flow rate of hydrogen supplied from the hydrogen supply line L1 to the reaction tower la is set to 200 NLZh, and the hydrogen from the hydrogen supply line L4 added to the cracked product from the reaction tower la is added. The flow rate was 50 NLZh. In the reaction towers la and lb, the liquid space velocity of the raw material is 2. Oh ^_1 (the liquid flow rate is 300 mlZh), the hydrogen partial pressure is 3.5 MPa, and the light fraction having a boiling point of 360 ° C or less with respect to the mass of the raw material wax. The reaction temperature (reaction towers la and lb were the same temperature) was adjusted so that the mass of the reactor became 80% by mass. The reaction temperature in this example was 355 ° C.

[0044] The decomposition product obtained by hydrocracking was analyzed by gas chromatography to determine the yield of the middle distillate (145-360 ° C distillate). The hydrogen consumption was determined by quantifying the hydrogen in the offgas and calculating the difference from the supply amount. The results obtained are shown in Table 1.

[0045] (Example 2) The hydrocracking of wax was carried out in the same manner as in Example 1 except that the flow rate of hydrogen supplied to the reaction tower la from the hydrogen supply line LI was 20 NLZh, and the yield and hydrogen consumption of the middle distillate were obtained. Asked. The results obtained are shown in Table 1. In this example, as in Example 1, the reaction temperature (reaction towers la and lb were the same temperature) was adjusted so that the mass of the light fraction having a boiling point of 360 ° C or less relative to the mass of the raw material wax was 80% by mass. When adjusted, the reaction temperature was 358 ° C.

[Comparative Example 1]

The wax was hydrocracked in the same manner as in Example 1 except that hydrogen from the hydrogen supply line L4 was not added to the cracked product from the reaction tower la. The hydrogen consumption was determined. The results obtained are shown in Table 1. In this comparative example, as in Example 1, the reaction temperature (reaction towers la and lb were the same temperature) was adjusted so that the mass of the light fraction having a boiling point of 360 ° C or less with respect to the mass of the raw material wax was 80% by mass. When adjusted, the reaction temperature was 360 ° C.

[0047] (Comparative Example 2)

The wax was hydrocracked in the same manner as in Example 1 except that the catalyst charge was 30 ml in the reaction tower la and 120 ml in the reaction tower lb, and the yield and hydrogen consumption of the middle distillate were determined. The results obtained are shown in Table 1. In this comparative example, as in Example 1, the reaction temperature was adjusted so that the mass of the light fraction having a boiling point of 360 ° C or less with respect to the mass of the raw material powder was 80% by mass (both the reaction towers la and lb had the same temperature ), The reaction temperature was 356 ° C

[0048] (Example 3)

USY zeolite (SiO 2 ZA12 O = 40molZmol)

3 and Silica Zirco Your (Silica Z Zirco

-A = 1.5 molZmol) and an alumina binder, a cylindrical carrier with a diameter of about 1.5 mm and a length of 3 mm was formed (USY zeolite Z silica zircoyu Z alumina binder = 3: 7: 90 (mass) Ratio))). This support was impregnated with an aqueous solution of chloroplatinic acid, and 0.8% by mass of platinum was supported on the support. This was dried and fired to obtain a hydrocracking catalyst.

[0049] The wax was hydrocracked in the same manner as in Example 1 except that the hydrocracking catalyst thus obtained was used, and the yield and hydrogen consumption of the middle distillate were determined. Obtained The results are shown in Table 1. In this example, as in Example 1, the reaction temperature (reaction towers la and lb are the same temperature) so that the mass of the light fraction having a boiling point of 360 ° C or less with respect to the mass of the raw material wax is 80% by mass. Was adjusted, and the reaction temperature was 311 ° C.

[0050] (Comparative Example 3)

The wax was hydrocracked in the same manner as in Example 3 except that hydrogen was not supplied from the supply port 3b of the reaction tower la, and the yield of the middle distillate and the hydrogen consumption were determined. The results obtained are shown in Table 1. In this comparative example, as in Example 1, the reaction temperature was adjusted so that the mass of the light fraction having a boiling point of 360 ° C or less with respect to the mass of the raw material wax was 80% by mass (both of the reaction towers la and lb were the same temperature). As a result, the reaction temperature was 313 ° C.

[0051] [Table 1]

[0052] As shown in Table 1, in Examples 1 to 3, the hydrocracking catalyst layers 2a and 2b are represented by the formula (1) where the distances d and d from the upstream end to the downstream end thereof are expressed by the formula (1). To meet the conditions

1 2

In addition to the supply of hydrogen to the hydrocracking catalyst layer 2a, hydrogen is added to the cracked products from the hydrocracking catalyst layer 2a between the hydrocracking catalyst layer 2a and the hydrocracking catalyst layer 2b. By adding, the yield of middle distillate could be improved sufficiently and the hydrogen consumption could be reduced sufficiently.

Industrial applicability

According to the wax hydrocracking method of the present invention, the yield of middle distillate can be sufficiently improved, and the consumption of hydrogen can be sufficiently reduced.

Claims

Claims [1] The first hydrocracking catalyst layer on the upstream side of the fixed bed reactor and the second hydrocracking catalyst layer on the downstream side satisfy the conditions expressed by the following formula (1), respectively. And hydrogen and wax are circulated through the first hydrocracking catalyst layer, and the cracking from the first hydrocracking catalyst layer is performed upstream of the upstream end of the second hydrocracking catalyst layer. A method for hydrocracking a wax, wherein hydrogen is added to a product, and a mixture containing the cracked product and the added hydrogen is circulated through the second hydrocracking catalyst layer. d / (d + d) ≥1 / 3 (1) 1 1 2

2

[2] The amount of hydrogen added to the cracked product from the first hydrocracking catalyst layer on the upstream side of the upstream end of the second hydrocracking catalyst layer is the amount of the first hydrocracking catalyst 2. The wax hydrocracking method according to claim 1, wherein the content is 5% by volume or more with respect to the amount of hydrogen supplied to the catalyst layer.

[3] The method for hydrocracking a wax according to claim 1 or 2, wherein the wax is a wax obtained by Fischer-Tropsch synthesis.

[4] The hydrogen of wax according to any one of claims 1 to 3, wherein each of the first and second hydrocracking catalyst layers contains ultra-stabilized Y-type zeolite. Chemical decomposition method.