JP2002302680A - Refining method for heavy oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refining method for a heavy oil which refines a low-cost heavy oil and is simple, reliable, and economically excellent. SOLUTION: The raw material oil for this method is a heavy oil with a hydrogen content of 12 wt.% or lower. After the oil is subjected to solvent extraction so as to increase the hydrogen content by 0.2 wt.% or higher, the oil is hydrogenated so as to further increase the hydrogen content by 0.5 wt.% or higher, thus giving a refined oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying heavy oil by a solvent extraction treatment and a hydrorefining treatment capable of efficiently removing impurities derived from crude oil. The present invention relates to a heavy oil refining method capable of obtaining a refined oil suitable also as a raw material for lower olefin production from heavy oil that has not been obtained.

[0002]

2. Description of the Related Art Petroleum products starting from crude oil contain impurities derived from their origin in the crude oil. It is produced after various chemical purification processes. Generally, a petroleum fraction, i.e., a distillate separated from the top by distillation, has less of the above impurities,
Since impurities can be removed by a simple refining process, it is used as a high-quality petroleum product, a high-grade fuel oil such as an automobile fuel or a gas turbine fuel, a petrochemical raw material, or the like, from which impurities are highly removed.

On the other hand, for heavy oils such as distillation residue oils,
Impurities are not only concentrated and present in a large amount but also in a form that is very difficult to remove, and there is a limit to the removal of the impurities in hydrorefining, which is a basic purification means. Particularly in the case of highly refined, high temperature and high temperature in the presence of hydrogen and a catalyst
At present, severe reaction conditions at high pressure are required, a large amount of hydrogen and catalyst are consumed, and a large investment including equipment cost is required, which is not economical at present. Therefore, a method for easily and economically obtaining a high-quality refined oil having high added value from heavy oil, that is, from which impurities are highly removed has been desired.

[0004] One of the uses of high quality refined oil is as a raw material for petrochemicals. Lower olefins such as ethylene and propylene, which are key substances in the petrochemical field, are produced by thermal cracking using light oils such as ethane and naphtha as main raw materials, but some heavy oils such as light gas oil and vacuum gas oil are used. Quality fractions are also used as raw materials. In the U.S. and the Middle East where natural gas is abundant and inexpensive, ethylene plants using the former ethane are the mainstream, but in Japan, Asia and Europe where naphtha is cheaper, the latter is mostly used in most cases. is there.

In an ethylene plant using naphtha as a raw material, by-products such as tar and pitch are generated more than when ethane is used as a raw material, so that a pyrolysis tube as a main reactor and a quenching heat exchanger in a subsequent stage are used. It is necessary to cope with coking and fouling. It is considered that vacuum gas oil having a higher molecular weight than naphtha and containing more metals and sulfur is the limit of commercial operation as a raw material for an ethylene plant.

[0006] On the other hand, from the viewpoint of the amount of raw material supplied and the raw material cost, if a raw oil that is heavier than a gas oil fraction can be used as a raw material for producing lower olefins, the raw material cost is low and the petroleum resources are heavier. This also solves the problem of stable supply of feedstock, which makes an extremely large contribution to industry.

The present invention has been made in view of the above circumstances, and provides a method for economically recovering a high-value-added refined oil from a heavy oil containing a high concentration of crude oil-derived impurities. It is particularly suitable as a raw material for lower olefin production by refining heavy oil such as atmospheric residue, which has been previously unsuitable as a raw material for lower olefins, by a simple and reliable method. An object of the present invention is to provide a method for refining heavy oil from which refined oil can be recovered.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, the hydrogen content was 12 wt.
% Of heavy oil as a raw material, and then subjected to solvent extraction to increase the hydrogen content by a certain amount or more, and then to increase the hydrogen content by a hydrorefining treatment of the obtained deasphalted oil. By such treatment, it was found that impurities in heavy oil could be efficiently removed, and a high-quality refined oil from which impurities were highly removed was obtained, and the present invention was completed.

[0009] That is, the present invention provides a solvent extraction step in which a raw oil is subjected to a solvent extraction treatment to obtain an extracted oil, and a hydrogenation treatment in which the obtained extracted oil is hydrogenated in the presence of hydrogen and a catalyst to obtain a refined oil. A method for refining heavy oil, wherein a refined oil is obtained by a treatment including a refining step, wherein the raw material oil has a hydrogen content of 12 wt%.
The following heavy oils are introduced into the solvent extraction step, and the solvent extraction process is performed so that the hydrogen content is increased by 0.2% by weight or more with respect to the base oil. DAO) to obtain a refined oil by introducing a deasphalted oil to a hydrorefining process and subjecting the deasphalted oil to hydrorefining so that the hydrogen content is increased by 0.5% by weight or more with respect to the deasphalted oil. And a refining process.

[0010] With this configuration, impurities that are difficult to remove in the subsequent hydrorefining are treated in advance by solvent extraction under a condition in which the hydrogen content increases by a certain amount or more, and then a certain amount of hydrogen is purified by the hydrorefining step. In order to process under the condition that the content increases, high-quality refined oil from which impurities are highly unpredictable that cannot be predicted by each refining process alone,
Can be obtained reliably. The present inventors have focused on the fact that simply carrying out the solvent extraction step and the hydrorefining treatment cannot reliably carry out the impurities, and the solvent extraction using the hydrogen content of the heavy oil to be treated as an index. It has been found that by performing the treatment so as to increase the hydrogen content by a predetermined amount in each of the step and the subsequent hydrorefining step, it is possible to reliably and efficiently obtain a highly purified oil from which impurities have been removed. Therefore, the conditions of the solvent extraction step and the hydrorefining step are not made severe, and can be obtained under economic conditions in which the load balance is maintained.

Further, the present invention provides a method for refining heavy oil, characterized in that the hydrogen content of the refined oil obtained above is 11.5 wt% or more, preferably 12.0 wt% or more. Things. When the refined oil thus obtained is used as a raw material for producing lower olefins, which is a raw material for petrochemicals, the occurrence of coking and fouling is suppressed even during the pyrolysis reaction, and commercial operation becomes possible. Things. For this reason, the refining method of the present invention is an economically superior method capable of reliably and efficiently obtaining a high-value-added refined oil.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has a hydrogen content of 12 wt.
%, Preferably 10 to 12 wt% of a heavy oil as a raw material, in the solvent extraction step and the hydrorefining treatment step, each of which is processed under a condition to achieve a predetermined degree of purification.
Heavy oils of 12 wt% or less used in the present invention generally correspond to residual oils such as atmospheric residual oils, ultra-heavy crude oils and the like, and their use is limited due to high impurity concentration. The hydrogen content of these heavy oils is generally 9-12.5% by weight, often 9-1-1% by weight.
In the prior art, the impurities were not sufficiently removed even by refining, and thus were not suitable for petrochemical materials such as those for lower olefins and were not used.

According to the present invention, a heavy oil having a hydrogen content of 12 wt% or less is used as a raw material oil, and a solvent extraction treatment is carried out as a first step to obtain an extracted oil having a hydrogen content of 0.2 wt% or more. Recover asphalten oil. In this solvent extraction treatment step, asphaltene components having a low hydrogen content are selectively removed. This asphaltene component has a micellar structure composed of a compound having a low hydrogen content such as a condensed polycyclic aromatic or cycloparaffin ring, and contains therein a porphyrin compound of residual carbon and metals such as V and Ni. It is known that impurities are concentrated.
It is also known that the asphaltene component significantly suppresses the hydrorefining reaction and promotes the deterioration of the catalyst. In the present invention, the solvent extraction treatment is carried out under the condition that the hydrogen content increases by 0.2 wt% or more. As a result, a predetermined amount of asphaltene is selectively removed.

For the solvent extraction treatment, a conventionally known solvent de-history treatment can be applied.
By countercurrent contact with the C5 solvent, the oil is separated into deasphalted oil and asphaltene having a low hydrogen content and enriched in metals and residual carbon. And
By appropriately selecting the type of solvent used, the amount of solvent with respect to heavy oil, and the extraction temperature conditions, the hydrogen content can be reduced to 0.2 watts.
The extraction oil of the present invention can be obtained by controlling the extraction treatment conditions so as to increase by at least t%. As the C3 to C5 solvent, at least one selected from propane, butane, and pentane is preferably used.

The deasphaltenated oil can be obtained by recovering the extract together with the solvent as an extract from the top of the extraction column, and separating and removing the solvent in the extract in a supercritical state. Asphaltene is recovered from the bottom of the column together with a portion of the solvent as a raffinate, and the solvent in the raffinate is recovered by evaporation.

In the present invention, the hydrogen content of the deasphalted oil obtained in the solvent extraction step is increased by 0.2% by weight or more than the hydrogen content of the raw heavy oil. Furthermore, it is preferable to increase by 0.2 to 1.5 wt%, and it is particularly preferable to increase by 0.2 to 1.2 wt%.

Further, it is preferable that the amount of increase in the hydrogen content in the solvent extraction treatment is changed depending on the value of the hydrogen content of the raw material heavy oil. That is, the hydrogen content of the feedstock is 11 wt%
In the above case, the extraction processing conditions may be controlled so that the hydrogen content is increased by 0.2 to 1.0 wt%, particularly 0.2 to 0.5 wt% with respect to the feed oil in the solvent extraction step. preferable. Further, when the hydrogen content is less than 11.0 wt%, 0.5 to 1.5 wt%, particularly 0.8 to 1.3 w%.
Increases in the range of t% are preferred.

When the content of hydrogen in the solvent extraction step is increased to 0.2 wt% or less, the removal of asphaltene, which is an impurity, becomes insufficient, and the impurity is sufficiently removed even in the subsequent hydrorefining step. This is an indispensable condition because it becomes impossible. On the other hand, the upper limit of the increase is better from the viewpoint of the degree of refining, but it is not economical to increase the amount by 1.5 wt% or more because the recovery of the deasphaltenated oil decreases.

In the present invention, the deasphaltenated oil which has been subjected to the solvent extraction treatment so as to increase the hydrogen content by 0.2% by weight or more in the solvent extraction treatment is subjected to a hydrorefining treatment as a subsequent second step. In the hydrorefining treatment of the present invention, treatment is performed under the condition that the hydrogen content increases by 0.5 wt% or more. This hydrorefining treatment is a typical purification treatment for treating hydrocarbons at high temperature and pressure in the presence of a catalyst and hydrogen, and includes reactions such as hydrocracking, hydrodesulfurization, hydrodemetallation, and hydrodenitrogenation. Can be included. That is, hydrocracking to obtain a low molecular weight refined oil from a raw heavy oil, hydrodesulfurization in which a sulfur compound in a hydrocarbon is reacted with hydrogen and separated into hydrogen sulfide to obtain a refined oil having a lower sulfur concentration than the raw oil Hydrogenation of metal compounds in hydrocarbons under high-temperature and high-pressure hydrogen, turning them into elemental metals and depositing them on catalysts to obtain refined oils with low metal concentration, hydrodemetallization in hydrocarbons under high-temperature and high-pressure hydrogen Reacting with nitrogen, hydrogen and ammonia to separate,
It may include all reactions such as hydrodenitrogenation to obtain a refined oil having a low nitrogen concentration from the feedstock.

Heavy oil contains impurities such as sulfur and metal as impurities. However, since it is difficult to remove impurities which are difficult to remove in the preceding solvent extraction step only by the hydrorefining step, severe oil is removed. The impurities can be efficiently removed to a low concentration without setting the conditions. As the catalyst used in the hydrorefining treatment of the present invention, it is preferable to use a combination of at least two kinds selected from a hydrodemetallation catalyst, a hydrodesulfurization catalyst, a hydrodesulfurization demetallation catalyst, and a hydrocracking catalyst. Preferably, the catalyst used for hydrorefining is Co /
Mo, Ni / Co / Mo, and Ni / Mo.

There are no particular restrictions on the conditions for the hydrorefining reaction, but the range of commonly used hydrorefining reaction conditions is preferred. That is, the hydrogen partial pressure is 60 to 150 kg / c.
m ² is preferred, and 80 to 130 kg / cm ² is particularly preferred. Further, the hydrogen / oil ratio is 400 to 1200 Nm ³ / k.
1 is preferable, and 600 to 1000 Nm ³ / kl is particularly preferable. LHSV is preferably 0.1 to 1.0 / hr, particularly preferably 0.2 to 0.8 / hr. The reaction temperature is preferably from 340 to 440 ° C, particularly preferably from 350 to 420 ° C.

Such conditions are general conditions for hydrorefining. In the present invention, if the hydrotreating step is carried out under the condition that the hydrogen content increases by 0.5 wt% or more after the preceding solvent extraction step, the final purification Impurities as oil can be efficiently removed. In the present invention, when the hydrogen content of the feedstock is 11 to 12 wt%, the increase in the hydrogen content of the refined oil obtained in the hydrorefining step with respect to the deasphalted oil is 0.5 to 1.0 wt%. Especially 0.5 to 0.9
It is preferably in wt%. When the hydrogen content of the feedstock is less than 11 wt%, the increase in the hydrogen content of the refined oil obtained in the hydrorefining step with respect to the deasphalted oil is 0.6 to 1.5 wt%, particularly 0.8 wt%. ~ 1.3w
It is preferably t%.

Further, the increase in the hydrogen content in the hydrorefining treatment step of the present invention is based on the fact that the hydrogen content of the deasphalted oil obtained in the preceding solvent extraction step is 11.5 wt%.
If it is not less than 0.5 wt%, the amount is preferably 0.5 to 1.0 wt%, and if it is less than 11.5 wt%, it is 0.6 to 1.0 wt%.
Preferably, the amount is 1.5 wt%. If the amount of increase in the hydrogen content in the hydrorefining treatment step is less than 0.5 wt%, the removal of impurities from the deasphalted oil becomes insufficient. It is not economical because the processing conditions of the hydrorefining reaction, such as pressure, reaction temperature, and catalyst loading, must be severe.

That is, from the viewpoint of the reaction conditions for hydrorefining, in the solvent extraction step, asphaltene, which is an impurity which is difficult to be removed in the hydrorefining step, is selectively removed in advance, so that the subsequent hydrogenation step is carried out. In the purification treatment step, impurities can be efficiently removed to a low concentration without extremely increasing the hydrogen partial pressure or the reaction temperature, and without significantly increasing the amount of catalyst and lengthening the reaction time. As a result, Conradson residual carbon and metals such as Ni and V, which are present in a form that is difficult to remove by being concentrated in asphaltenes, are selectively removed by solvent extraction, and then easily removed by hydrorefining treatment. In this way, impurities such as sulfur and metals such as Ni and V which are present can be intensively removed.

The refined oil treated in the refining process according to the present invention can be used as a raw material for producing lower olefins, and when it is subjected to high-temperature pyrolysis, impurities which cause caulking and fouling are reliably and efficiently produced. Therefore, it can be applied to commercial production due to the lower olefin yield and continuous operation. This means that a high-quality refined oil can be obtained by a simple refining process using a heavy oil such as a residual oil or a super-heavy crude oil, which has conventionally been considered unsuitable as a lower olefin raw material, as a starting material.

In the present invention, any refined oil treated under the conditions satisfying the above conditions is effective as the refined oil of the present invention, but when used as a raw material for producing lower olefins, the hydrogen content is particularly low. It is necessary to be 11.5 wt% or more, and it is more preferable that it is 12.0 wt% or more.

In the present invention, the hydrogen content of the refined oil obtained by two-stage refining of heavy oil by solvent extraction and hydrorefining is increased by 0.7% by weight or more compared with the raw heavy oil. And it is preferably 0.8 to 2.7 wt%, more preferably 1.0 to 2.2 wt%. When used as a raw material for producing lower olefins, the hydrogen content of the final refined oil is 11.5 wt.
%, Preferably 12.0 to 13.5 wt%
% Is more preferable.

The solvent extraction process and the hydrorefining process are performed so that the hydrogen content of the refined oil is 11.5 wt% or more and 0.7 wt% or more than that of the heavy fuel oil.
The characteristics in each treatment are complemented with each other, and a highly refined refined oil can be obtained in high yield without imposing an excessive load on equipment for solvent extraction and hydrorefining in each step. Even when applied to petrochemical raw materials, caulking and fouling hardly occur, and a refined oil suitable for petrochemical raw materials can be produced in high yield.

In the step of solvent-extracting heavy oil of the present invention, the extraction operation is performed under the condition that the hydrogen content of the raw oil is increased by 0.2 wt% or more. It contains tens to thousands of wtppm. Since these are concentrated in asphaltene and asphaltene can be selectively removed in the solvent extraction step, the content in the deasphalted oil is extracted by the solvent extraction treatment to obtain Ni + V in the deasphalted oil which is a refined oil.
Metal concentration of 70 wtppm or less, especially 50 wtpp
m or less. In addition, the residual carbon content is 1
It is preferable to perform the solvent extraction treatment so as to be 5 wt% or less, particularly 12 wt% or less. That is, the solvent extraction process increases the hydrogen content by 0.2 wt%,
It is preferable that the concentration of i + V metal be 70 wtppm or less and the residual carbon of Conradson be 15 wt% or less, whereby impurities can be reliably removed without making the subsequent hydrorefining treatment conditions severe, and high-quality refined oil can be obtained. Obtainable.

Further, the sulfur concentration of the deasphalted oil was adjusted to 5%.
It is preferably set to not more than 4 wt%, especially not more than 4 wt%.
Thereby, the sulfur content of the final refined oil obtained in the subsequent hydrorefining treatment is 0.5 wt% or less, preferably 0.3 wt%.
The processing can be reliably performed as follows. By setting the Ni + V concentration of the deasphalted oil to 70 wtppm or less, the residual carbon concentration to 15 wt% or less, and the sulfur concentration to 5 wt% or less, the Ni + V concentration of the final refined oil obtained in the subsequent hydrorefining treatment is 2 wtppm or less, preferably 1 wtppm. In the following, the treatment can be reliably performed so that the residual carbon concentration is 1 wt% or less and the sulfur concentration is 0.5 wt% or less, preferably 0.3 wt% or less. By setting the sulfur content of the final refined oil to 0.5% by weight or less, even when used as a raw oil for lower olefins, corrosion of the thermal cracking unit can be suppressed within the allowable range of the material, and substantially lower Commercial production of olefin raw materials can be enabled.

In the present invention, Ni + V of the final refined oil is used.
Metal content is 2wtppm or less, especially 1.0wtppm
It is preferable to perform the solvent extraction treatment and the hydrorefining treatment as described below. Deasphaltened oil whose Ni + V metal content is reduced to 70 wt ppm or less by solvent extraction treatment,
Hydrogen refining further increases Ni + V metal content by 1 wtppm
By setting the content as described below, coking can be remarkably reduced and a refined oil can be obtained in a high yield, and the refined oil can be used as a raw material for thermal decomposition for producing lower olefins.

In an industrial process for producing a lower olefin containing ethylene and propylene by a pyrolysis reaction, the maintenance efficiency against decoking and fouling due to heavy by-product oil and the olefin yield determine the economic efficiency. In particular, the yield of the lower olefin is at least 25%. A closer look at lower olefins shows that the ethylene yield is at least 15% and the propylene yield is at least 10%.

In addition, coking and fouling with by-product heavy oil, which affect the maintainability of the thermal decomposition apparatus, are dealt with by regular decoking and cleaning. In particular, as for by-product heavy oil, when the high-temperature decomposition products decomposed in the decomposition tube are quenched by downstream heat exchange to prevent excessive decomposition, when the amount of heavy oil generated is large, Blocks heat exchangers and piping, making long-term continuous operation impossible. When starting from heavy oil as in the present invention, the amount of by-produced heavy oil generated in the thermal cracking reaction can be used as a standard for commercial operation.

The refined oil obtained by the present invention is obtained by refining a heavy oil having a hydrogen content of 12% by weight or less, which has not been used as a raw material for producing lower olefins such as ethylene, as a raw material for producing lower olefins. In this case, the olefin yield and coking properties during thermal decomposition are good, and industrial production is possible.

In the present invention, when the content of impurities in the distillate obtained by simple distillation separation of crude oil or the like is small, or when the content of impurities can be reduced by simple purification, the crude oil is used as a starting material. As a distillate oil and a residual oil, and the residual oil, that is, the atmospheric distillation residual oil or the vacuum distillation residual oil, is subjected to solvent extraction and hydrorefining treatment as described above to obtain a refined oil, and the refined oil is subjected to the above distillation. A refined oil can be obtained by mixing at least a part of the refined oil after hydrorefining.

In this case, if the solvent extraction step and the hydrorefining step satisfy the criteria for increasing the hydrogen content of the present invention,
By mixing the distillate oil having a low impurity content, the total impurity concentration can be reduced and the supply amount of the refined oil can be increased. When supplied as a raw oil for producing lower olefins, coking and fouling in the thermal decomposition reaction are further less likely to occur, and commercial production can be made possible.

[0037]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

Examples 1 to 4 and Comparative Examples 1 to 5 Example 1 Heavy oil which is a residual oil having an API specific gravity of 14.3 (hydrogen content: 11.25 [wt%], Ni + V metal: 65 [wtp]
pm], Conradson carbon residue (CCR):
11.1 [wt%], S: 3.95 [wt%]) as a feed oil were introduced into a solvent extraction treatment apparatus, and the extraction rate was 81 wt% using a normal pentane solvent (solvent / Oil ratio: 8/1). After extraction and separation to obtain a deasphalted oil (hereinafter referred to as DA0), the deasphalted oil was purified under the following hydrorefining conditions to obtain a purified oil 1 of the present invention. Hydrorefining conditions: Ni / Mo + Ni / Co / Mo catalyst (1/9 by volume ratio), hydrogen partial pressure: 90 [atm], H ₂ /
Oil ratio: 600 [Nm ³ / kl], temperature: 380 ° C, L
HSV: 0.5 [1 / hr] The yield, hydrogen content, increase in hydrogen content in each step, V + Ni content, CCR, and sulfur concentration of the obtained deasphalted oil and refined oil 1 with respect to the base oil, It is shown in Table 1. The hydrogen content was measured by CHN elemental analysis.

Example 2 The raw material oil used in Example 1 was introduced into a solvent extraction treatment apparatus,
Using normal pentane solvent (solvent / Oi
1 ratio: 8/1) After extracting and separating to obtain an extraction rate of 84 wt% to obtain deasphalted oil, DAO was hydrorefined under the same conditions as in Example 1 to obtain a purified oil 2 of the present invention. Was.
The yield of the obtained DAO and refined oil 2 with respect to the feed oil,
Hydrogen content, increase in hydrogen content in each step, V +
Table 1 shows the Ni content, CCR, and sulfur concentration.

Example 3 The raw material oil used in Example 1 was introduced into a solvent extraction treatment apparatus.
Using normal pentane solvent (solvent / Oi
1 ratio: 8/1) DAO was obtained by extraction and separation so as to have an extraction rate of 81 wt%, and then the DAO was purified under the following hydrorefining conditions to obtain a purified oil 3 of the present invention. Hydrorefining conditions: Ni / Mo + Ni / Co / Mo catalyst (1/9 by volume ratio), hydrogen partial pressure: 85 [atm], H ₂ /
Oil ratio: 600 [Nm ³ / kl], temperature: 360 ° C, L
HSV: 0.5 [1 / hr] Yield of the obtained DAO and refined oil 3 with respect to the feed oil,
Hydrogen content, increase in hydrogen content in each step, V +
Table 1 shows the Ni content, CCR, and sulfur concentration.

Example 4 The raw material oil used in Example 1 was introduced into a solvent extraction treatment apparatus.
Using an isobutane / normal pentane mixed solvent (so
lvent / Oil ratio: 8/1) After extraction and separation to obtain an extraction rate of 76 wt% to obtain DAO, the DAO was purified under the following hydrorefining conditions to obtain a purified oil 4 of the present invention. Hydrorefining conditions: Ni / Mo + Ni / Co / Mo catalyst (1/9 in volume ratio), hydrogen partial pressure: 110 [atm], H ₂
/ Oil ratio: 800 [Nm ³ / kl], temperature: 380 ° C,
LHSV: 0.3 [1 / hr] Yield of the obtained DAO and refined oil 3 with respect to the feed oil,
Hydrogen content, increase in hydrogen content in each step, V +
Table 1 shows the Ni content, CCR, and sulfur concentration.

[0042]

[Table 1]

Comparative Example 1 Using the same raw oil as in Example 1, the solvent extraction rate was 88%.
After extracting and separating under the same extraction conditions as in Example 1 to obtain DAO, DAO was hydrorefined under the following hydrorefining conditions to obtain comparative purified oil A. Hydrorefining conditions: Ni / Mo + Co / Mo catalyst (1/9 by volume ratio), hydrogen partial pressure: 90 [atm], H ₂ / Oil:
600 [Nm ³ / kl], temperature: 360 ° C, LHSV:
0.5 [1 / hr] The yield of the obtained DAO and refined oil A with respect to the feed oil,
Hydrogen content, increase in hydrogen content in each step, V +
Table 2 shows the Ni content, CCR, and sulfur concentration.

COMPARATIVE EXAMPLE 2 DAO was obtained by using the same feedstock oil as in Example 1 and extracting and separating it using a normal pentane solvent (solvent / Oil ratio: 8/1) so that the extraction rate became 86 wt%. Thereafter, the DAO was purified under the following hydrorefining conditions to obtain a purified oil B for comparison. Hydrorefining conditions: Ni / Mo + Co / Mo catalyst (1/9 by volume ratio), hydrogen partial pressure: 90 [atm], H ₂ / Oil:
600 [Nm ³ / kl], temperature: 360 ° C, LHSV:
0.5 [1 / hr] The yield of the obtained DAO and refined oil B with respect to the feed oil,
Hydrogen content, increase in hydrogen content in each step, V +
Table 2 shows the Ni content, CCR, and sulfur concentration.

Comparative Example 3 The same raw oil as in Example 1 was extracted and separated using a normal pentane solvent (solvent / Oil ratio: 8/1) to an extraction rate of 81 wt% to obtain DAO. After that, the DAO was purified under the following hydrorefining conditions to obtain comparative purified oil C. Hydrorefining conditions: Ni / Mo + Co / Mo catalyst (1/9 by volume ratio), hydrogen partial pressure: 90 [atm], H ₂ / Oil:
600 [Nm ³ / kl], temperature: 345 ° C., LHSV:
0.6 [1 / hr] The yield of the obtained DAO and refined oil C with respect to the feed oil,
Hydrogen content, increase in hydrogen content in each step, V +
Table 2 shows the Ni content, CCR, and sulfur concentration.

Comparative Example 4 Using the same raw material oil as in Example 1, and using a propane solvent (solvent / oil ratio: 8/1), an extraction rate of 45 w
Extraction and separation were performed so as to obtain a purified oil D for comparison.
Yield of the obtained refined oil D with respect to the feed oil, hydrogen content,
Increase in hydrogen content in each step, V + Ni content,
Table 2 shows the CCR and sulfur concentrations.

Comparative Example 5 A refined oil E for comparison was obtained by using the same raw oil as in Example 1 and purifying it under the following hydrorefining conditions. Hydrorefining conditions: Ni / Mo + Co / Mo catalyst (1/9 by volume ratio), hydrogen partial pressure: 150 [atm], H ₂ / Oi
l: 1000 [Nm ³ / kl], temperature: 380 ° C, LHS
V: 0.25 [1 / hr] Yield of the obtained refined oil E with respect to the base oil, hydrogen content,
Increase in hydrogen content in each step, V + Ni content,
Table 2 shows the CCR and sulfur concentrations.

[0048]

[Table 2]

Production Examples of Lower Olefins The final refined oils obtained in Examples 1 to 4 and Comparative Examples 1 to 5 were respectively pyrolyzed under the following conditions. Reaction conditions: Reaction tube: Uses an HPM material ethylene cracking tube having an inner diameter of 28 mm and a length of 1440 mm (heating portion: 1200 mm). Raw material supply: 1.69 [L / Hr] of raw material oil, and water is weight ratio to raw material oil. Adjust the supply amount to be 1.0 Reaction temperature: 900 ° C Pressure: Normal pressure Residence time: 0.5 seconds Obtained lower olefin (ethylene and propylene)
Was determined from the amount of product gas and the gas composition in the product gas analyzed using gas chromatography. The amount of by-product heavy oil produced is
The oil produced after cooling the pyrolysis gas was determined from the bottom oil amount after the naphtha fraction was separated by distillation. In addition, the determination of the continuous operability is based on the weight ratio of the by-product heavy oil, which is a cause of fouling, precipitated in the quenching portion branched from the reaction tube to the feed oil, 30 wt% or less = ○, 30 wt% or more = It was determined as x. Table 3 shows the results.

[0050]

[Table 3]

In Examples 1 to 4 of the present invention, DAO obtained by the solvent extraction treatment was extracted such that the hydrogen content was increased by 0.2% by weight or more as compared with the heavy feed oil. The hydrogen content was treated to increase by 0.5 wt% or more compared to DAO, and as a result, the final refined oil was treated to increase by 0.7 wt% or more compared to heavy feed oil. In the refined oil of the present invention, V + Ni is 0.1 wtppm or less and Conradson residual carbon is 0.8% or less.
A refined oil from which impurities were removed to a wt% or less and a sulfur concentration of 0.3 wt% or less was obtained. On the other hand, in Comparative Examples 1 to 5 which do not satisfy the increase in the hydrogen content of the present invention, Conradson residual carbon in the final refined oil is 0.8 wt% or more,
The sulfur concentration is 0.3 wt% or more.

In particular, with the solvent extraction treatment alone, the sulfur concentration did not decrease even when the DAO extraction rate was reduced, and with the hydrorefining treatment alone, Conradson residual carbon could be removed even if the hydrogen consumption was greatly increased. It turns out there is no. Also,
As a result of producing a lower olefin by subjecting the obtained refined oil to a thermal decomposition treatment, the refined oil of the present invention has an ethylene yield of more than 15%, a propylene yield of more than 10%, and The continuous operability was judged to be within the possible range based on the production status of fresh heavy oil. On the other hand, in Comparative Examples that do not satisfy the present invention, the ethylene yield does not exceed 15%, and furthermore, the amount of by-produced heavy oil generated is large, and it can be seen that there is a problem in any of the continuous operability.

Example 5 Heavy oil which is a residual oil having an API specific gravity of 4.2 (hydrogen content:
10.68 wt%, Ni + V metal: 246 wt ppm,
(CCR: 25 wt%, S: 5.5 wt%) as a feed oil into a solvent extraction treatment apparatus, and using an isobutane solvent (solvent / Oil ratio: 8/1), an extraction rate of 63 wt.
% To obtain DAO, and then DAO was hydrorefined under the following conditions to obtain a purified oil 5 of the present invention. Hydrorefining conditions: Ni / Co / Mo + Co / Mo catalyst (2/8 by volume ratio), hydrogen partial pressure: 110 [atm], H ₂
/ Oil ratio: 800 [Nm ³ / kl], temperature: 380 ° C,
LHSV: 0.3 [1 / hr] Yield of the obtained DAO and refined oil 5 with respect to the feedstock,
Hydrogen content, increase in hydrogen content in each step, V +
Table 4 shows the Ni content, CCR, and sulfur concentration.

Example 6 Using the same feedstock oil as in Example 5, and using an isobutane solvent (solvent / oil ratio: 8/1), the extraction rate was 65.
wt% to obtain DAO,
O was purified under the following hydrorefining conditions to obtain a purified oil 6 of the present invention. Hydrorefining conditions: Ni / Mo + Co / Mo catalyst (2/8 by volume ratio), hydrogen partial pressure: 140 [atm], H ₂ / Oi
l: 1000 [Nm ³ / kl], temperature: 375 ° C, LHS
V: 0.2 [1 / hr] The yield of the obtained DAO and refined oil 6 with respect to the feed oil,
Hydrogen content, increase in hydrogen content in each step, V +
Table 4 shows the Ni content, CCR, and sulfur concentration.

[0055]

[Table 4]

Comparative Example 6 Using the same raw oil as in Example 5, using an isobutane solvent (solvent / oil ratio: 8/1), the extraction rate was 65.
wt% to obtain DAO,
O was purified under the following hydrorefining conditions to obtain a purified oil F for comparison. Hydrorefining conditions: Ni / Mo + Co / Mo catalyst (2/8 by volume ratio), hydrogen partial pressure: 80 [atm], H ₂ / Oil:
800 [Nm ³ / kl], temperature: 340 ° C., LHSV:
0.5 [1 / hr] The yield of the obtained DAO and refined oil F with respect to the feed oil,
Hydrogen content, increase in hydrogen content in each step, V +
Table 5 shows the Ni content, CCR, and sulfur concentration.

Comparative Example 7 Using the same raw oil as in Example 5, and using an isobutane solvent (solvent / Oil ratio: 8/1), the extraction rate was 55.
It was extracted and separated so as to be wt% to obtain comparative purified oil G. Table 5 shows the yield, hydrogen content, increase in hydrogen content in each step, V + Ni content, CCR, and sulfur concentration of the obtained refined oil G with respect to the feedstock oil.

Comparative Example 8 The same raw oil as in Example 5 was subjected to a refining treatment under the following hydrorefining conditions to obtain a comparative purified oil H. Hydrorefining conditions: Ni / Mo + Co / Mo catalyst (3/7 by volume ratio), hydrogen partial pressure: 140 [atm], H ₂ / Oi
l: 1000 [Nm ³ / kl], temperature: 375 ° C, LHS
V: 0.2 [1 / hr] Yield of the obtained refined oil H with respect to the feed oil, hydrogen content,
Increase in hydrogen content in each step, V + Ni content,
Table 5 shows CCR and sulfur concentrations.

[0059]

[Table 5]

Production Example of Lower Olefins Each of the final refined oils obtained in Examples 5 to 6 and Comparative Examples 6 to 8 was pyrolyzed under the same conditions as described above, and the yield of lower olefins Table 6 shows the production rate of fresh heavy oil and the results of determination of continuous operation.

[0061]

[Table 6]

In Examples 5 to 6 of the present invention, in the solvent extraction treatment step, the hydrogen content was 0.2 w
Extraction is performed to increase the hydrogen content by 0.5% or more in comparison with DAO in the subsequent hydrorefining process. As a result, the final refined oil is Therefore, it has increased by 0.7% by weight or more. In the obtained refined oil of the present invention, the Ni + V concentration is 0.1 wtppm or less, the CCR is 1 wt% or less, and the sulfur concentration is 0.5 wt% or less. Has been obtained.

On the other hand, in Comparative Example 7, which was purified only by the solvent extraction treatment, it was found that the impurities were not sufficiently removed even when the recovery was reduced to 55% and the extraction and purification were performed. In addition, comparing Example 6 of the present invention with Comparative Example 8 purified only by hydrorefining, it was found that there was a large difference in the removal of impurities despite the same conditions for hydrorefining. It can be seen that, after the predetermined hydrogen content is increased by the extraction treatment, the impurities are remarkably removed by the hydrorefining treatment, and a high-quality refined oil is obtained. further,
As a result of producing a lower olefin by subjecting the obtained refined oil to a thermal decomposition treatment, the purified oil of the present invention showed an ethylene yield of 15%.
%, The propylene yield exceeded 10%, and the continuous operation was judged to be in a possible range from the state of production of heavy by-product oil. On the other hand, in Comparative Examples not satisfying the present invention,
It can be seen that the ethylene yield did not exceed 15%, and that the amount of by-produced heavy oil was large, and that all of the continuous operability had problems.

Example 10 Production of Refined Oil Starting from Heavy Crude Oil Arabian heavy crude oil having an API specific gravity of 27.4 was separated into a distillate oil and a residual oil by distillation, and a part of the distillate oil was hydrorefined. And got GO. On the other hand, API specific gravity as residual oil is 10.
Using the heavy oil No. 9 as the raw material oil 1, a solvent extraction treatment and a hydrorefining treatment were performed under the same conditions as in Example 1 of the present invention to obtain a refined oil 10. Part of this refined oil 10 (crude oil 100
(20 parts by weight based on parts by weight) and the above GO and a part of the feedstock 2 (10 parts by weight based on 100 parts by weight of crude oil) are mixed and used as a pyrolysis raw material for producing lower olefins to produce lower olefins did. Table 7 shows the yield, hydrogen content, Ni + V metal content, CCR content, and S content of the atmospheric residue, deasphalted oil, hydrorefined deasphalted oil, and heavy ethylene feedstock of Example 10. .

[0065]

[Table 7]

In Example 10, the residual oil was used as the raw material oil.
A refined oil obtained by performing the refining treatment of the present invention is mixed with a separately prepared distillate having a low impurity concentration to obtain a raw material for producing lower olefins. Were confirmed to be satisfactory results.

[0067]

According to the refining method of the present invention, a heavy oil having a hydrogen content of 12% by weight or less can be reliably and economically refined to obtain a refined oil with reduced impurities. Limited, the use of heavy oil can be greatly expanded. In addition, when the refined oil obtained by the present method is used as a raw material for producing lower olefins, ethylene and propylene can be produced at an economically reasonable yield. It is possible to set the range as possible.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Higashi 2-3-1 Minatomirai, Nishi-ku, Yokohama-shi, Kanagawa Prefecture Inside JGC Corporation (72) Inventor Motoi Sasaki 2-3-1 Minatomirai, Nishi-ku, Yokohama-shi, Kanagawa Prefecture JGC Corporation (72) Inventor Susumu Kasahara 2-3-1 Minatomirai, Nishi-ku, Yokohama-shi, Kanagawa Prefecture Within JGC Corporation (72) Inventor Yasushi Fujimura 2205 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki Prefecture F-term (in Japanese) Reference) 4H029 DA02 DA05 DA09

Claims (8)

[Claims] 1. A solvent extraction step for obtaining an extracted oil by subjecting a raw oil to solvent extraction, and a hydrorefining step for hydrotreating the obtained extracted oil in the presence of hydrogen and a catalyst to obtain a refined oil. A method for refining heavy oil to obtain a refined oil by a treatment comprising:
The feedstock is a heavy oil having a hydrogen content of 12 wt% or less. The feedstock is introduced into the solvent extraction step, and the solvent extraction treatment is performed so that the hydrogen content is increased by 0.2 wt% or more with respect to the feedstock. Asphaltene oil (DAO) which is extracted oil
And a hydro-refining process in which the deasphalted oil is introduced into the hydrorefining process, and the hydrogen content is increased by 0.5% by weight or more with respect to the deasphalted oil to obtain a purified oil. And a process for refining heavy oil. 2. A solvent extraction step of subjecting the raw oil to solvent extraction to obtain an extracted oil, and a hydrorefining step of hydrotreating the obtained extracted oil in the presence of hydrogen and a catalyst to obtain a refined oil. A method for refining heavy oil to obtain a refined oil by a treatment comprising:
The feedstock is a heavy oil having a hydrogen content of 12 wt% or less, and the feedstock is introduced into the solvent extraction step, and the solvent extraction is performed so that the hydrogen content is increased by 0.2 wt% or more with respect to the heavy oil. Deasphaltened oil (DAO) which is processed and extracted oil
And a hydro-refining process in which the deasphalted oil is introduced into the hydrorefining process, and the hydrogen content is increased by 0.5% by weight or more with respect to the deasphalted oil to obtain a purified oil. Wherein the hydrogen content of the refined oil whose hydrogen content obtained in the hydrorefining step has increased by 0.7 wt% or more with respect to the feed oil is 11.5 wt% or more. For refining high quality oil. 3. An increase in the hydrogen content of the deasphaltenated oil obtained in the solvent extraction step with respect to the feed oil, which is 0.2 to 0.2%.
1.5 wt%, the increase in hydrogen content of the refined oil obtained in the hydrorefining step with respect to the deasphalted oil is
The method for refining heavy oil according to claim 1 or 2, wherein the amount is 0.5 to 1.5 wt%. 4. The feedstock having a hydrogen content of 11 to 12 watts.
t%, and the increase in the hydrogen content of the deasphalted oil obtained in the solvent extraction step with respect to the feedstock oil is 0.2 to 1.
0 wt%, and the increase in the hydrogen content of the refined oil obtained in the hydrorefining step with respect to the deasphalted oil was 0.5%.
The method for refining heavy oil according to any one of claims 1 to 3, wherein the amount is from 1.0 to 1.0 wt%. 5. The method according to claim 1, wherein the hydrogen content of the base oil is less than 11 wt%, and the increase in the hydrogen content of the deasphalted oil obtained in the solvent extraction step with respect to the base oil is 0.5 to 1.5.
wt%, and the increase in the hydrogen content of the refined oil obtained in the hydrorefining step with respect to the deasphalted oil is from 0.6 to 0.6%.
The method for refining heavy oil according to any one of claims 1 to 4, wherein the amount is 1.5 wt%. 6. The solvent extraction treatment so that the total amount of Ni and V in the deasphalted oil is 70 wt ppm or less and Conradson residual carbon is 15 wt% or less.
The method for refining heavy oil according to any one of claims 1 to 5. 7. The purified oil obtained by the solvent extraction step and the hydrorefining step has a V + Ni content of 2 wtppm or less, a Conradson residual carbon content of 1 wt% or less, and a sulfur content of 0% or less. 2. The composition according to claim 1, wherein the content is not more than 0.5 wt%.
7. The method for refining heavy oil according to any one of claims 6 to 6. 8. The method according to claim 1, wherein at least a part of the refined oil is used as a pyrolysis feedstock for producing lower olefins, and a hydrogen content in the pyrolysis feedstock is 12.0 wt% or more. 3. The method for purifying heavy oil according to claim 1.