JPS60152594A - Desulfurization of residual oil from direct desulphurizer - Google Patents

Abstract

PURPOSE:To make it possible to remove sulfur efficiently in the subsequent solvent deasphalting step, by adjusting asphalten or Conradson carbon residue content of residual oil from a direct desulfurizer to a predetermined level in a distillation, vaporization or solvent extraction equipment. CONSTITUTION:Residual oil from a direct desulfurizer 1 is led into a distillation, vaporization or solvent extraction equipment 2 and its asphalten content is adjusted to 6wt% or higher or its Conradson carbon residue content is adjusted to 9wt% or higher. The residual oil is then introduced into a solvent deasphalting equipment 3 to produce light oil and deasphalted oil with a low sulfur content. Deasphalted oil as raw material for fluid catalytic cracking is obtained efficiently with a higher yield and at a higher ratio of desulfurization than in the case with solvent deasphalted residual oils of vacuum or normal pressure distillation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides direct desulfurization equipment residue oil, which is obtained by directly feeding atmospheric distillation residue oil mainly made from heavy crude oil into a desulfurization equipment, by distillation equipment, evaporation equipment, or solvent extraction. The asphaltene content (heptane insoluble content) or Conradson residual 1 element content (hereinafter referred to as
By adjusting the OCR content to a predetermined value, the sulfur content can be removed with high efficiency in the next step, the solvent deasphalt equipment, and the direct desulfurization equipment can efficiently obtain the raw material for the fluidized 4P catalytic cracker. This invention relates to a method for desulfurizing residual oil.

Traditionally, the oil refining industry has responded to heavier crude oil, increased sulfurization, and environmental regulations, and has also increased the size of refined oil.
A large number of direct desulfurization units have been installed for the purpose of increasing the oil yield, but the properties of the residual oil obtained by these units are as shown in the example in Table 1 when Arabian heavy crude oil is used as the main raw material. The CCR content includes 70% of metals, and the 1MC yellow content is around 0.5%, so harsh operating conditions are required to expect higher desulfurization efficiency9, and the catalyst life is shortened, making it uneconomical. Ta.

(Left below) Table 1 For this reason, in the past, residual oil from direct desulfurization equipment was used as a heavy oil mixture base, where sulfur content was not a problem, along with metal content and OCR content9. When used as a raw material, it was necessary to mix it with a large amount of desulfurized direct-run gas oil or vacuum gas oil in order to dilute the metal content that can poison the catalyst and the sulfur content that is restricted by environmental regulations. In particular, when the treated crude oil becomes heavy and sufficient raw material for fluid catalytic cracking cannot be obtained, it is strongly desired to use residual oil from direct desulfurization as raw material for fluid catalytic cracking. At this time, the total amount of sulfur is subject to environmental regulations, which poses a major constraint, and therefore measures are needed to reduce its sulfur content. On the other hand, conventional solvent deasphalting methods, typically represented by supercritical solvent deasphalting methods, are positioned as equipment for upgrading heavy residual oil.

Figure 1 shows the relationship between the metal content, CCR content, sulfur content Q removal rate, and deasphalted oil yield when vacuum distillation residual oil, mainly Arabian Heavy, is subjected to a solvent deasphalting device using butane solvent. There is. As can be seen from this figure, the solvent deasphalting method is effective in removing vanadium, removing nickel, and removing OCR, but cannot be expected to have a great effect in removing sulfur.

Conventionally, processes that combine direct desulfurization equipment and solvent deasphalting equipment have been proposed for the purpose of demetalization, de-OCR, and desulfurization, but none of these methods expects the desulfurization effect from the solvent-based deasphalting equipment. Ta.

In the process of researching the deasphalting performance of solvent desulfurization equipment, the present inventors conducted solvent deasphalting tests with various types of oil, and discovered that the solvent deasphalting effect of direct desulfurization equipment residual oil was unique. I found it. In other words, as a result of applying the solvent deasphalting method, which was conventionally thought to have no desulfurization effect, to the residual oil of the direct desulfurization equipment, it was discovered that a high desulfurization rate could be obtained by concentrating the asphaltene content in the residual oil to a predetermined value or higher. .

Based on this knowledge, we further conducted 4If research and completed the present invention.

That is, in the present invention, when solvent deasphalting of direct desulfurization equipment residual oil of relatively heavy crude oil is carried out using a solvent such as propane, butane, or pentane, the asphaltene content (heptane insoluble content) and CCR By adjusting the amephaltene content to 6% by weight or more and the CCR content to 9% by weight or more in the distillation device, evaporation device, or solvent extraction device, extremely high efficiency can be achieved in the next step, the solvent deasphalting device. It is characterized by desulfurization.

Hereinafter, the configuration of the present invention will be explained in detail based on the drawings.

FIG. 2 is an explanatory diagram showing the configuration of an apparatus for carrying out the present invention. In the figure, 1 is a direct desulfurization device, 2 is a distillation device, evaporation device, or solvent extraction device, and 3 is a solvent deasphalt device. In Fig. 2, the direct desulfurization equipment residual oil obtained by the direct desulfurization equipment 1 is introduced into a distillation equipment, or an evaporation equipment 1, and a solvent extraction equipment 2, where the asphaltene content (heptane insoluble content) in the direct desulfurization equipment residue oil is removed. ) is adjusted to 6% by weight or more, preferably 8.0% by weight or more, or the CCR content is adjusted to 9% by weight or more, desirably 1000% by weight or more, and then descaling is performed using the solvent descaling device 3. (Obtain light oil with low yellowing content and deasphalted oil.

The feature of the present invention is the unique behavior of the sulfur content when direct desulfurization equipment residual oil is deasphalted with a solvent. Table 2 shows the properties of the deasphalted oil obtained as a result of solvent deasphalting as butane.

(Left below) Table 2: Compared to solvent deasphalting of vacuum distillation residue oil or atmospheric distillation residue oil, the effect of deasphalting is distinctive, and although the yield of deasphalted oil is high, desulfurization The rate was relatively high. This is thought to be due to the fact that the first stream yellow distribution of the direct tax+St equipment residual oil is different from that of the vacuum distillation equipment residual oil. In particular, since the desulfurization rate is correlated with the removal OCR rate, the sulfur content in the residual oil of the direct desulfurization equipment is unevenly distributed in relatively stable polymer compounds, that is, asphaltenes, which are not decomposed even under direct desulfurization conditions. It was estimated that there was. Based on this assumption, we conducted an experiment to investigate the extraction conditions for obtaining a high desulfurization rate, and found that the OCR content was 9% by weight or more, and 1 load was 10.5%↓
It has been found that it is extremely effective when the concentration is adjusted to d% or more, or annuphaltene content 6 tons %lLh, preferably 8.0% by weight or more. If the OCR content is 9% by weight or less or the asphaltenes content is 6% by weight or less, the deasphalting oil removal rate will significantly decrease and become uneconomical if a sufficient desulfurization rate is to be obtained; When trying to obtain a high yield of Anuphalt, the desulfurization rate drops significantly.Therefore, in order to achieve both high yield and high desulfurization rate, it is necessary to increase the yield of deasphalt. That is, it is necessary to ensure that the OCR content in the residual oil of the direct desulfurization equipment is 9% by weight or more, and the asphaltene content is 6% by weight or more.

Table 3 shows the effect of asphaltene OCR concentration adjustment. - As an example, VGO (vacuum gas oil/I
/) and deasphalting oil, with a total oil removal rate of one shift being constant,
When deasphalting the solvent using butane solvent under the same conditions with a 1M agent ratio of 6, the oil properties obtained in the case where concentration adjustment was not performed and when concentration adjustment was performed are shown. There is.

Table 3 In this case, the asphaltene content is a-condensed using a vacuum distillation device! At the same oil extraction rate, the desulfurization rate improved by about 20%, making it extremely easy to reach a sulfur content of 0.1%, which was previously only possible under extremely harsh desulfurization conditions. . At the same time, in combination with the demetalization effect, which is the original effect of the solvent deasphalting equipment, we were able to achieve properties that could be easily processed in a fluid catalytic cracking equipment, with a yield of 90%. From the viewpoint of desulfurization, this study shows that a high desulfurization rate can be easily achieved by combining a direct desulfurization equipment and a solvent deasphalt equipment.
This invention can be said to be a useful invention that can significantly reduce the load under direct desulfurization conditions, which has been achieved with great expense and operating costs, and at the same time can effectively provide raw materials for fluid catalytic cracking equipment.

Figure 3 shows the relationship between the desulfurization rate, metal removal rate, and oil removal rate in solvent deasphalting using a butane solvent using direct desulfurization equipment reduced pressure I/jJ obtained in the course of research related to the present invention, residue oil as raw material. Shown below. Compared to the results of solvent deasphalting of the vacuum residual oil shown in FIG. 1, an overall improvement in the metal removal rate was observed, and the improvement in the desulfurization rate was particularly notable. In particular, regarding the desulfurization rate, it is recognized that the yield of deasphalted oil rapidly decreases when it exceeds 80%. It has been found that it is effective to adjust the asphaltene content or CCR content to a predetermined amount or more using a vacuum distillation apparatus or the like in order to simultaneously achieve a high oil yield and a high sulfur content. Regarding the method for adjusting the asphaltene content and CCR content, a vacuum distillation apparatus was used in the examples described below, but this may also be replaced by a solvent extraction apparatus. In this case, the solvent extraction apparatus has a low extraction rate of about 50%. By adjusting the desulfurization rate and high demetallization rate and further removing the residual oil with a solvent, the same effect as when using a vacuum distillation apparatus can be obtained. The same applies even if an evaporator is still used. In addition, the high sulfur content of the residual oil from the direct desulfurization equipment obtained by the solvent arm rub method is due to the fact that the sulfur content is unevenly distributed in the asphaltene content. The same effect can be obtained with the mixed solvent of It is particularly effective when applied to direct desulfurization equipment residual oil from heavy crude oil such as Arabian Heavy and Khafji.

Examples of the present invention are shown below.

Example: The residual oil obtained by directly desulfurizing the atmospheric distillation residual oil of a mixed crude oil mainly composed of Arabian Heavy (having the properties shown in Table 1) was applied to a vacuum distillation apparatus, and ■ GO was cut.
Asphal 1f (heftane insoluble content) 8.6% by weight, O
The CR content was adjusted to 11.1% by weight. Table 4 shows the properties of the vacuum residual oil from the direct desulfurization equipment at this time. This residual oil was extracted using butane as a solvent at a solvent ratio of 6 and a temperature of 110 to 130°.
Solvent leakage occurred in the C range. The yield and properties of the resulting deasphalted oil are shown in Table 4, and the yield and properties of the deasphalted asphalt are shown in Table 5.

(Margin below) Table 5

[Brief explanation of the drawing]

Figure 1 is a graph showing the relationship between the deasphalted oil yield, metal removal rate, and sulfur removal rate obtained when vacuum residue of crude oil, mainly Arabian Heavy, was subjected to solvent scraping using a butane solvent.
Figure 2 is a flow sheet showing the configuration of an apparatus for carrying out the method of the present invention, and Figure 3 is a direct desulfurization equipment for crude oil, mainly Arabian Heavy. It is a graph showing the relationship between the deasphalted oil yield, the metal removal rate, and the desulfurization rate. 1... Direct desulfurization equipment, 2... Vacuum distillation equipment or solvent extraction equipment, 3... Solvent arm scraping equipment

Claims (1)

[Claims] 1. Introduce the direct desulfurization equipment residual oil to a distillation unit, evaporation equipment, or solvent extraction equipment to adjust the amephaltene content in the direct desulfurization equipment residue oil to 6% by weight or more or the Conradson residual carbon content to 9% by weight or more, and then 1. A method for desulfurizing oil from a direct desulfurization apparatus, characterized in that the residual oil is passed through a vulcanization apparatus.