JP5631612B2 - Heavy hydrocarbon oil cracking catalyst - Google Patents

Description

  The present invention relates to a catalyst used for cracking heavy hydrocarbon oil, and in particular, heavy fuel oil used for producing light hydrocarbon oil from heavy hydrocarbon oil without supplying hydrogen from outside the system. The present invention relates to a catalyst for cracking a hydrocarbon oil.

  Conventionally, light hydrocarbon oils containing monocyclic aromatic compounds having only one aromatic ring, such as benzene, toluene, xylene, etc., which are useful as raw materials for petrochemical products, are converted into polycyclic aromatic compounds or polycyclic aromatic compounds. As a method for producing from a heavy hydrocarbon oil containing a group compound, a thermal decomposition method, a hydrocracking method, and the like are known (see, for example, Patent Document 1 and Patent Document 2).

  Patent Documents 3 to 4 also disclose a method for producing a light hydrocarbon oil by decomposing a heavy hydrocarbon oil while using an iron-based catalyst in a steam-containing atmosphere.

JP 2003-96471 A JP 2008-297452 A JP 2002-129171 A JP 2006-7151 A

  However, when a conventional thermal decomposition method is used, the aromatic ring is hardly cleaved, so the production efficiency of light hydrocarbon oil containing a low molecular weight hydrocarbon compound such as a monocyclic aromatic compound is poor, There is a problem that heavy hydrocarbon oil cannot be decomposed sufficiently. In addition, when the hydrocracking method is employed, a large amount of high-pressure hydrogen gas is used for the cracking reaction, so that a large-scale hydrogen gas production facility is required, which may increase the cost.

  On the other hand, when an iron-based catalyst is used as described above, the catalyst itself is inexpensive, but may not show stable activity in a steam atmosphere, and if it has a crystal form such as iron oxide, Since its form is easily changed by the decomposition reaction, the catalytic activity may be impaired.

  Therefore, the present invention provides a heavy hydrocarbon oil cracking catalyst having good activity, which can efficiently produce light hydrocarbon oil from heavy hydrocarbon oil without using high-pressure hydrogen gas. For the purpose.

  In order to solve the above problems, the present inventors have found a catalyst capable of efficiently producing light hydrocarbon oil from heavy hydrocarbon oil by containing a specific element in a specific amount, and the present invention. It came to complete.

That is, the heavy hydrocarbon oil cracking catalyst of the present invention is
It is used when cracking heavy hydrocarbon oils in the presence of water, is a complex oxide of Group 4A elements and Al ₂ O _3, and contains Group 4A elements in an amount of 20 % by mass or more. It is characterized by.
Further, the Group 4A element may be titanium or zirconium.

  By using the heavy hydrocarbon oil cracking catalyst of the present invention, light hydrocarbon oil can be efficiently produced from heavy hydrocarbon oil without using high-pressure hydrogen gas. Useful.

It is a graph which shows the result of having observed the crystal form before and behind use of the catalyst A obtained in Example 1 by X-ray spectroscopic analysis (XRD). The vertical axis represents the diffraction intensity, and the horizontal axis represents the incident angle 2θ. It is a graph which shows the result of having observed the crystal form before and behind use of the catalyst B obtained in Example 2 by X-ray spectroscopic analysis (XRD). The vertical axis represents the diffraction intensity, and the horizontal axis represents the incident angle 2θ. It is a graph which shows the result of having observed the crystal form before and behind use of the catalyst C obtained by the comparative example 1 by X-ray spectroscopic analysis (XRD). The vertical axis represents the diffraction intensity, and the horizontal axis represents the incident angle 2θ.

Hereinafter, the present invention will be specifically described.
The heavy hydrocarbon oil cracking catalyst of the present invention is
It is used when decomposing heavy hydrocarbon oil in the presence of water and is characterized by containing a Group 4A element in an amount of 10% by mass or more.

  The heavy hydrocarbon oil cracking catalyst of the present invention contains a Group 4A element in an amount of 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more. Specific examples of the Group 4A element include titanium (Ti), zirconium (Zr), and hafnium (Hf). These may be used alone or in combination of two or more. May be. Of these, titanium or zirconium is more preferable. By including such a Group 4A element within the above range, a catalyst that exhibits high activity even when used in the presence of water and is hardly deactivated can be obtained. That is, the heavy hydrocarbon oil cracking catalyst of the present invention is different from the hydrothermally synthesized zeolite catalyst or γ-alumina single catalyst used in the hydrocracking reaction of hydrocarbon oil, Even when heavy hydrocarbon oil is decomposed in the presence of water, the crystal structure of the catalyst is not significantly changed by high-temperature and high-pressure steam, and the catalyst cannot be used. There is no need to pre-treat hydrocarbon oil.

As the catalyst, specifically, a catalyst containing a titanium element such as a catalyst composed only of a Group 4A element or a catalyst containing titanium dioxide (TiO ₂ ) can be used. More specifically, for example, a catalyst made of only Ti, a catalyst made of only Zr, a catalyst made of only Hf, a catalyst made of an alloy containing a Group 4A element such as a titanium alloy, or a technique such as plating or vapor deposition. Catalysts coated on the surface with these Group 4A elements, oxides of Group 4A elements such as TiO ₂ manufactured by the coprecipitation method, and metals in the third to fourth periods of the periodic table such as Al ₂ O ₃ A catalyst composed of a complex oxide with an oxide of an alkali metal (excluding alkali metal and alkaline earth metal) is used . In particular, the catalyst is preferably a composite oxide of TiO ₂ and Al ₂ O ₃ or a composite oxide of ZrO ₂ and Al ₂ O ₃ . However, from the viewpoint of maintaining a more suitable catalytic activity, the content of Fe and its oxide (Fe ₂ O ₃ ) in the catalyst is desirably 40% by mass or less in terms of iron element, and more desirably 30%. It is more desirable that the content is not more than mass%, further not more than 20 mass%, and does not substantially contain these. Note that the crystal structure of the Group 4A element oxide used in the catalyst may be any crystal structure.

When the heavy hydrocarbon oil cracking catalyst of the present invention is a catalyst comprising a composite oxide of TiO ₂ and Al ₂ O ₃ , it can be produced, for example, by the following method.

  First, titanium dioxide and aluminum nitrate are dissolved in ion-exchanged water in an amount such that Ti / Al (molar ratio) is 0.15 to 100 to form an aqueous solution, and aluminum oxide is added to titanium dioxide in a magnetic dish. The slurry is supported to form a slurry. Next, after mixing these, left still at room temperature for 1 to 24 hours, and further dried for 0.5 to 2 days while dissolving the massive precipitate several times in the middle with a dryer set at 70 to 150 ° C., The catalyst raw material is obtained by sizing. The obtained catalyst raw material is calcined at 400 to 1000 ° C. for 0.5 to 10 hours to produce the heavy hydrocarbon oil decomposition catalyst of the present invention.

  When cracking heavy hydrocarbon oil using the catalyst for cracking heavy hydrocarbon oil of the present invention, the heavy hydrocarbon oil is brought into contact with the catalyst in the presence of water. Such water is used as a hydrogen source when the high molecular weight hydrocarbon compound contained in the heavy hydrocarbon oil is decomposed into a lower molecular weight hydrocarbon compound, that is, when it is lightened. The amount of water may be an amount sufficient to lighten the heavy hydrocarbon oil, for example, 10 to 3000 parts by weight, preferably 100 parts by weight with respect to 100 parts by weight of the heavy hydrocarbon oil. It is desirable to add to heavy hydrocarbon oil in an amount of 20 to 2000 parts by mass, more preferably 20 to 1000 parts by mass. When the addition amount of water is less than 10 parts by mass with respect to 100 parts by mass of the heavy hydrocarbon oil, the heavy hydrocarbon oil may not be sufficiently lightened. On the other hand, when the amount of water added exceeds 3000 parts by mass, the amount of water that does not contribute to the lightening action increases, which may increase the cost or reduce the production efficiency of the light hydrocarbon oil. is there.

  The heavy hydrocarbon oil that is a raw material oil is not particularly limited, and may be, for example, an atmospheric distillation residue, a vacuum distillation residue, or the like obtained during petroleum refining. The heavy hydrocarbon oil is a mixture of various hydrocarbon compounds mainly containing relatively high molecular weight hydrocarbon compounds, and the resulting light hydrocarbon oil has been reduced in molecular weight by the decomposition of the hydrocarbon compounds. It is a mixture of various hydrocarbon compounds. If the weight average molecular weight of the heavy hydrocarbon oil is 500 or more, the weight average molecular weight of the obtained light hydrocarbon oil can be 250 or less. In addition, a weight average molecular weight means here the polystyrene conversion value by gel permeation chromatography (GPC).

  The light hydrocarbon oil is also a mixture of various hydrocarbon compounds like the above heavy hydrocarbon oil, and the weight average molecular weight of the light hydrocarbon oil means the weight average molecular weight of the mixture. For example, when the heavy hydrocarbon oil contains a condensed polycyclic aromatic compound such as 1-methylnaphthalene, quinoline, anthracene, or phenanthrene, or a non-condensed polycyclic aromatic compound such as dibenzothiophene or biphenyl, etc. By cleaving the ring into a monocyclic aromatic compound with a very high probability, it is possible to produce a light hydrocarbon oil having a weight average molecular weight of not more than half, preferably not more than 1/3 of that of heavy hydrocarbon oil. As described above, when the heavy hydrocarbon oil is decomposed using the heavy hydrocarbon oil cracking catalyst of the present invention, the heavy hydrocarbon oil as the raw material oil can be effectively lightened, and the utility value can be reduced. High catalyst.

And the said catalyst is filled in a reactor, for example, A light hydrocarbon oil can be manufactured by making the mixture of heavy hydrocarbon oil and water contact with this. Here, the conditions for bringing the catalyst into contact with the mixture in the reactor are, for example, a temperature of 300 to 600 ° C., preferably 350 to 550 ° C., more preferably 400 to 500 ° C., for example, a temperature as high as 500 ° C. is suitable. Compared with the conventional method using an iron-based catalyst, it is possible to carry out in a relatively low temperature range. The pressure is 0.5 to 50 MPa, preferably 1.0 to 40 MPa, more preferably 5 to 35 MPa, and the liquid space velocity is 0.01 to 10 h ⁻¹ , preferably 0.08 to 10 h ^−1. it can. If the temperature is lower than 300 ° C, the activation energy required for the reaction may not be obtained, and the decomposition of the heavy hydrocarbon oil may not proceed sufficiently. If it exceeds 600 ° C, unnecessary gases (methane, ethane, etc.) This is because a large amount of is generated and the productivity of light hydrocarbon oil may be reduced. In addition, when the pressure is less than 0.5 MPa, it may be difficult to smoothly flow the heavy hydrocarbon oil and water into the reactor, and when it exceeds 50 MPa, the production cost of the reactor may increase. There is. Furthermore, when the liquid space velocity is less than 0.01 h ⁻¹ , generation of unnecessary gas becomes dominant, and the productivity of light hydrocarbon oil may be reduced. If it exceeds 10 h ⁻¹ , the reaction time is short. Therefore, there is a possibility that the decomposition reaction of the heavy hydrocarbon oil does not proceed sufficiently.

  When using the heavy hydrocarbon oil cracking catalyst of the present invention, hydrogen necessary for the cracking reaction of heavy hydrocarbon oil is supplied from the water present in the system, so hydrogen is added from outside the system. do not have to. Therefore, in the heavy hydrocarbon oil cracking using the heavy hydrocarbon oil cracking catalyst of the present invention, the molar ratio of the hydrogen addition amount from the outside of the system and the heavy hydrocarbon oil supply amount (hydrogen addition amount / carbonization amount). The hydrogen oil supply amount) can be 0.1 or less, preferably 0. Therefore, light hydrocarbon oil can be efficiently produced from heavy hydrocarbon oil without using high-pressure hydrogen gas.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

Example 1: Preparation of catalyst A
For 50 g of TiO ₂ (MC-90, manufactured by Ishihara Sangyo Co., Ltd.), 36.78 g of aluminum nitrate (Al (NO ₃ ) ₃ .9H ₂ O) as a reagent is dissolved in ion-exchanged water to obtain a 77 ml aqueous solution. In a magnetic dish, TiO ₂ was supported on Al ₂ O ₃ to form a slurry. Next, after mechanical mixing, the mixture was allowed to stand at room temperature for 1 hour, and further dried for a whole day and night while dissolving the massive precipitate several times in the dryer at 130 ° C., and the average particle size was adjusted to 300 μm or less. A catalyst raw material having a granulated dry weight of 57.38 g was obtained.

  The obtained catalyst raw material was calcined at 600 ° C. for 3 hours in a muffle furnace, and this temperature was maintained for 2 hours to obtain 52.22 g of Catalyst A. The Ti content of catalyst A was 50.7 mass%, the Al content was 5.0 mass%, and the Ti / Al (molar ratio) was 5.72.

[Example 2: Preparation of catalyst B]
For 80 g of ZrO ₂ (XZO 631/05, manufactured by MEL), 42.7 g of aluminum nitrate (Al (NO ₃ ) ₃ .9H ₂ O) as a reagent is dissolved in ion-exchanged water to obtain a 55 ml aqueous solution. Al ₂ O ₃ was supported on ZrO ₂ to form a slurry. Next, after mechanical mixing, the mixture was allowed to stand at room temperature for 1 hour, and further dried for a whole day and night while dissolving the massive precipitate several times in the dryer at 130 ° C., and the average particle size was adjusted to 300 μm or less. A catalyst raw material having a granulated dry weight of 57.38 g was obtained.

  The obtained catalyst raw material was calcined at 600 ° C. for 3 hours in a muffle furnace, and this temperature was maintained for 2 hours to obtain 52.22 g of Catalyst B. The Zr content of Catalyst B was 66.2% by mass, the Al content was 4.7% by mass, and the Zr / Al (molar ratio) was 4.17.

[Comparative Example 1: Preparation of catalyst C]
For 50 g of Al ₂ O ₃ (γ-alumina, manufactured by Wako Pure Chemical Industries, Ltd.), 20.0 g of TiO ₂ (30% titanium sulfate solution) as a reagent is dissolved in ion-exchanged water to obtain a 63 ml aqueous solution. In a dish, TiO ₂ was supported on Al ₂ O ₃ to form a slurry. Next, after mechanical mixing, the mixture was allowed to stand at room temperature for 1 hour, and further dried for a whole day and night while dissolving the massive precipitate several times in the dryer at 130 ° C., and the average particle size was adjusted to 300 μm or less. A catalyst raw material having a granulated dry weight of 57.84 g was obtained.

The obtained catalyst raw material was calcined at 600 ° C. for 3 hours in a muffle furnace, and this temperature was maintained for 2 hours to obtain 53.13 g of Catalyst C. Catalyst C had a Ti content of 2.2 mass%, an Al content of 44.9 mass%, and a Ti / Al (molar ratio) of 0.03.
The compositions of the obtained catalysts A to C are shown in Table 1.

[Decomposition of heavy hydrocarbon oil]
In a superalloy (Inconel 625) reactor (internal volume 10 ml), 6.0 mL of each of the catalysts A to C obtained in Examples 1-2 and Comparative Example 1 was charged. Next, while ion-exchanged water was circulated at 30.0 mL / h in each reactor filled with the catalyst, it was heated and pressurized to a temperature of 470 ° C. and a pressure of 28 MPa, and then added to Table 2 without adding hydrogen. A heavy hydrocarbon oil having the composition shown (petroleum atmospheric pressure residue, weight average molecular weight = 1,500) was charged into the reactor at a rate of 6.0 ml / h. In addition, the weight average molecular weight was calculated | required by the polystyrene conversion value using the gel permeation chromatography (Apparatus: Agilent 1100, Column: PL3micrometer Guard (7.5 * 50mm) + 3micrometer Mixed-E (7.5 * 300mm 2 pieces)).

  And the product oil was extract | collected until 1 hour passed since 5 hours passed from the start of oil flow, and the distillation property of the product oil obtained according to ASTM D-287 was analyzed using gas chromatography. . Each result is shown in Table 2.

  * 1: Shows the results of evaluation of the crystal form of the catalyst after use by X-ray spectroscopic analysis (XRD).

When the crystal form of the catalyst after use was observed by XRD (FIGS. 1 to 3), the catalyst used in the examples showed almost no change in crystal form before use (evaluation result: ◯), but compared Catalyst C used in Example 1 indicates that γ-alumina (Al ₂ O ₃ ) was changed to boehmite (AlO (OH)) as a crystal system after use and was deactivated as a catalyst 6 hours after use. (Evaluation result: x).

  From these results, it can be seen that the light hydrocarbon oil can be effectively lightened by using the heavy hydrocarbon oil cracking catalyst of the present invention.

Claims (2)

It is used when cracking heavy hydrocarbon oils in the presence of water, is a complex oxide of Group 4A elements and Al ₂ O _3, and contains Group 4A elements in an amount of 20 % by mass or more. A catalyst for cracking heavy hydrocarbon oils.   The heavy hydrocarbon oil cracking catalyst according to claim 1, wherein the Group 4A element is titanium or zirconium.

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