JPH0216356B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for hydrotreating heavy oil, and more specifically, the present invention relates to a method for hydrotreating heavy oil, in particular, by deasphalting heavy feedstock oil using light oil produced by hydrocracking as a solvent, and then subjecting it to hydrocracking treatment. Relating to methods for achieving effective hydroprocessing. Conventionally, when heavy oil such as residual oil containing relatively large amounts of asphaltenes and metals is hydrocracked, if such heavy oil is hydrocracked as is, metals and carbon content will precipitate on the catalyst, resulting in a short period of time. Since the cracking activity decreases over time, a method of deasphalting with light hydrocarbons such as propane, butane, naphtha, etc. to remove asphaltenes and then hydrogenolyzing is used (see Figure 1). However, in the above method, it is necessary to provide a solvent recovery column 1 to separate the solvent from deasphalted oil and recover the solvent, and at the same time, it is necessary to supply deasphalted solvent from another process, which requires additional equipment. There are many disadvantages both in terms of production and operation, and the extraction efficiency is not sufficient. The present invention is a method that eliminates the drawbacks of the above-mentioned conventional methods and can obtain middle distillates in high yields. That is, the present invention provides a method for deasphalting heavy oil and then hydrocracking it to make it lighter. The deasphalted oil containing the deasphalted oil is introduced into a distillation column to separate the deasphalted oil and the solvent, and the obtained deasphalted oil is subsequently hydrocracked, and the product is introduced into the distillation column to separate each fraction. The present invention provides a method for hydrotreating heavy oil, characterized in that at least a portion of the light fraction obtained is used as a deasphalting solvent for the heavy feedstock oil. The heavy oil used in the present invention is a heavy oil in which the content of components having a boiling point of 343°C or higher is 70 vol% or more, preferably 85 vol% or more, and examples thereof include atmospheric distillation residue oil, vacuum distillation residue oil, etc. . The method of the present invention will be explained in more detail with reference to the drawings as follows. FIG. 2 is a flow diagram illustrating one embodiment of the method of the present invention. In FIG. 2, heavy feedstock oil is first introduced into an extraction column 2. On the other hand, in this extraction column 2, hydrogenolysis is carried out in a reaction column 3, which will be described later, and further, a distillation column 4 is added.
A light oil such as naphtha obtained by fractional distillation is introduced, and this light oil is used as a solvent to deasphalt the heavy raw material oil in this extraction column 2. Since this light oil contains a large amount of aromatic components, the extraction efficiency for atmospheric distillation residue oil is higher than when using a solvent such as propane. The operating conditions for the extraction tower are usually a temperature of 110 to 270°C;
The pressure is selected within the range of 10 to 50 Kg/cm ² and the solvent ratio is selected within the range of 1 to 10 vol/vol. After the deasphalting treatment, the bituminous material such as pitch is extracted from the bottom of the extraction column 2, while the extracted deasphalted oil is led to the distillation column 4 while containing light oil as a solvent. The deasphalted oil containing this solvent is distilled in the distillation column 4, but the solvent and the deasphalted oil are mainly separated, and it is not very likely that the deasphalted oil will be further fractionated into each component. First, most of the deasphalted oil collects at the bottom of the distillation column 4. The deasphalted oil from which the solvent has been separated in the distillation column 4 is extracted from the bottom of the distillation column 4 and introduced into the reaction column 3. In this reaction tower 3, the deasphalted oil is hydrocracked. The conditions for the hydrotreating here are not particularly limited and may be appropriately selected depending on the type of deasphalted oil (ie, the type of heavy feedstock oil), the purpose of the hydrotreating, and the like. In other words, the catalyst is a porous inorganic carrier such as alumina, alumina-boria, silica-alumina, silica-magnesia, or a carrier prepared by blending Y-type zeolite or ultra-stable Y-type zeolite with the porous inorganic carrier. (Mo, W), group (CO, Ni) metals and their sulfides supported singly or in combination can be used. Here, the ultrastable Y-type zeolite refers to a Y-type zeolite with a SiO ₂ /Al ₂ O ₃ molar ratio of 7 to 30 and a unit cell size of 23.00 to 24.60 Å. Preferred catalyst combinations use alumina-Y zeolite, alumina-ultrastable Y zeolite, alumina-boria-Y zeolite or alumina-boria-ultrastable Y zeolite as the support, and Ni-W as the metal. , Ni-Mo or Co-Mo
This is a combination using Here, the amount of Y-type zeolite or ultrastable Y-type zeolite in the carrier is 20 to 80 wt%, preferably 40 to 60 wt% of the carrier.
If it is less than 20wt%, the effects of zeolite will not be fully expressed, and if it is more than 80wt%, the shape-retaining strength of the catalyst cannot be ensured. When using alumina-boria as a matrix, the boria as B ₂ O ₃ in the matrix is 30wt% or less, preferably 20 to 10wt%.
%, the amount of solid acid in alumina-boria becomes maximum. The amount of metal supported is 1 to 11 wt%, preferably 2 to 11 wt% in the catalyst as a metal oxide for group metals.
7 wt%, and group metals as metal oxides in the catalyst in an amount of 8 to 32 wt%, preferably 10 to 21 wt%. The hydrogenolysis conditions include a reaction temperature of 300-480℃.
℃, reaction pressure 70-350Kg/ ^cm2G , hydrogen gas supply amount
500～ ^3000Nm3 /Kl-oil, liquid time space velocity (LHS
V) It is preferable to select in the range of 0.1 to 2. The product obtained by hydrogenolysis in the reaction column 3 is introduced into the distillation column 4 either by combining the solvent-containing deasphalted oil from the extraction column 2 or separately. In this distillation column 4, the hydrocracked product is fractionated into gas, light oil such as naphtha, middle distillate such as heavy naphtha, kerosene and light oil, residual oil, and the like. As mentioned above, not only the hydrocracked oil but also deasphalted oil containing a solvent is introduced into the distillation column 4, but this deasphalted oil is fractionated into each component. There is very little of it, and it is mostly separated from the solvent and accumulated at the bottom of the distillation column 4.
Therefore, in the method of the present invention, the distillation column 4 plays the role of fractionating the hydrocracked oil and at the same time serves as a solvent recovery column that separates the deasphalted oil and the solvent. In this distillation column 4, at least a part of the light oil obtained by fractional distillation of the light oil as a solvent and the hydrocracking product separated from the deasphalted oil is As a binder,
It is guided to extraction tower 2. On the other hand, the residual oil at the bottom of the distillation column 4 may be introduced into the reaction column 3 again for hydrocracking treatment, if necessary, and then further introduced into the distillation column 4. As mentioned above, since the method of the present invention uses light oil obtained by hydrocracking as the deasphalting solvent, the solvent can be self-sufficient, and there is no need to separately supply the solvent from other processes. First, since light oil contains a large amount of aromatic components, it has the advantage of high yield through extraction treatment, resulting in increased production of middle distillates. Furthermore, since a solvent recovery column for separating the solvent from the deasphalted oil is not required, equipment costs can be reduced. Therefore, the method of the present invention can be effectively utilized in the field of petroleum refining. Next, examples of the present invention will be shown. Examples 1 to 3 Using an apparatus having the flow shown in FIG. 2, tests were conducted using the atmospheric distillation residue of Chinese crude oil having the properties shown in Table 1 below as a raw material. In extraction column 2, deasphalting treatment was carried out under the conditions shown in Table 2, and the yield of deasphalted oil was approximately 95% by weight. Further, in the reaction tower 3, hydrogenolysis was carried out under the conditions shown in Table 4 using a hydrogenolysis catalyst having the composition shown in Table 3. In addition, extraction tower 2
The temperature at the inlet of distillation column 4 of the mixture of solvent-containing deasphalted oil and hydrocracked oil from the top of the column was set at about 300°C. The method of the present invention as described above was operated continuously, and the yield of produced oil after reaching a steady state was as shown in Table 5. The properties of the light oil used as a deasphalting solvent are shown in Table 6. Comparative Examples 1 and 2 Propane deasphalting treatment and hydrocracking treatment were carried out under the same conditions as Examples 1 to 3 using an apparatus having the flow shown in Figure 1. As a result, the yield of deasphalted oil was as follows. 90
It was in weight%. Moreover, the yield of the obtained product is shown in Table-5. Example 4 In Examples 1 to 3, instead of the HY type zeolite, the SiO ₂ /Al ₂ O ₃ molar ratio was 8.2 and the unit cell size was
Hydrogenolysis was carried out under the same conditions as in Examples 1 to 3, except that an ultrastable zeolite having an alkali metal content of 24.37 Å and 1.5 wt% or less as Na ₂ O was used.
The results are shown in Table-5. Comparative Example 3 Propane deasphalting treatment and hydrocracking treatment were carried out under the same conditions as in Example 4 using an apparatus having the flow shown in Figure 1. As a result, the yield of deasphalted oil was 90% by weight. It was hot. In addition, the yield of the obtained product is shown in the table.
5. Table-1 Specific gravity (D15/4℃) 0.8956 343℃ ⁺ (vol%) 94.0 Kinematic viscosity (CP50℃) 199 Pour point (℃) 40.0 Remaining coal (wt%) 4.4 Sulfur content (wt%) 0.15 Nitrogen content (wt %) 0.249 Vanadium content (ppm) 0.1 or less Nickel content (ppm) 5.0 Table 2 Tower top temperature (℃) 190 Tower bottom temperature (℃) 180 Pressure (Kg/cm ² G) 30 Solvent ratio (vol/vol) 5 Table-3 HY type zeolite (wt%) 44.25 AL ₂ O ₃ (wt%) 31.50 Nio (wt%) 4.25 WO ₃ (wt%) 17.00 Table-4 Reaction temperature (℃) 405, 395, 385 Reaction pressure (Kg /cm ² G) 150 LHSV (hr ^-1 ) 0.3 H ₂ /oil ratio (Nm ² /Kl) 2000

【table】

【table】 [Brief explanation of drawings]

FIG. 1 shows a flowchart of a conventional hydroprocessing method, and FIG. 2 shows a flowchart of one embodiment of the method of the present invention. 1... Solvent recovery column, 2... Extraction column, 3... Reaction column, 4... Distillation column.

Claims (1)

[Claims] 1 In a method of deasphalting heavy oil and then hydrocracking it to make it lighter, heavy feedstock oil is deasphalted using light oil produced by hydrocracking as a solvent, and then deasphalting containing the solvent is used. The oil is introduced into a distillation column to separate the deasphalted oil and the solvent, and then the obtained deasphalted oil is hydrocracked, and then the product is introduced into the distillation column to be separated into each fraction. A method for hydrotreating heavy oil, characterized in that at least a part of the light components obtained is used as a deasphalting solvent for the heavy feedstock oil.