JPH09296183A - Pretreatment of heavy oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the backwashing frequency of a filter and pretreat a heavy oil so as to reduce the exchange of a changeover device of oil passage/ backwashing by carrying out the dehydrating treatment of the heavy oil before introducing the heavy oil containing solid grains and moisture into the filter and increasing the oil passage time through the filter. SOLUTION: The dehydrating treatment of a heavy oil is previously carried out by heating, vacuum and contact operations with an inert gas or combined operations thereof, etc., when introducing the heavy oil containing solid grains and moisture (e.g. an atmospheric distillation bottom oil prepared by introducing a raw material oil containing the solid grains into a distillation column and distilling the raw material oil under atmospheric pressure while blowing steam thereinto and a vacuum distillation bottom oil obtained by introducing the atmospheric distillation bottom oil into a distillation column and distilling the atmospheric distillation bottom oil under a reduced pressure while blowing steam thereinto) into a filter. Furthermore, the dehydrating treatment is preferably performed so as to provide <=300wt.ppm. moisture content of the heavy oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to solid particles and water such as atmospheric residual oil obtained by atmospheric distillation of crude oil or vacuum residual oil obtained by vacuum distillation of atmospheric residual oil. The present invention relates to a pretreatment method when solid particles are filtered and separated from a heavy oil containing water.

[0002]

2. Description of the Related Art In crude oil pumped from a petroleum oil well, mud and other granular contaminants having different properties such as composition, content, particle size and the like depending on the place of production, oil collecting conditions and the like are entrained. These contaminants may spontaneously separate after oil collection due to precipitation during storage, but in many cases,
It is excluded as a secondary effect in pretreatment processes such as desalting and stabilizing, and rarely acts as a major inhibitor in the oil refining process. However, under certain conditions, it can have a significant adverse effect on the physical or chemical treatment of subsequent purification steps.

For example, in the case of Minas crude oil and Duri crude oil known as Southern crude oil, the crude oil delivered from the untreated oil storage tank contains mud, which is generally siliceous. According to a typical process scheme in petroleum refining, this crude oil is first washed with water and subjected to electrical desalination, and then supplied to an atmospheric distillation unit to distill distillates such as LPG, gasoline, kerosene, and gas oil, and a column bottom. While obtaining the oil (AR), each component is subjected to a respective refining step. According to the experience of the present inventors, in this case, it was observed that the mud particles were mostly collected in the heavy oil at the bottom of the distillation column, and this heavy oil was supplied to the next step, for example, a demetallization reactor. At this time, in order to prevent the mud particles from depositing in the reactor, it is desirable to remove particles having a particle size of 25 μm or more in advance. Therefore, the heavy oil is filtered.

The mud particles contained in Minas crude oil and Duri crude oil have been measured to have a maximum particle size of 10 μm, and should easily pass through a filter having an opening of 25 μm. Therefore, when we started the steady operation by adopting a slit type filter with an opening of 25 μm, which was designed to carry out oil supply and backwash according to the differential pressure program, unexpectedly the backwash frequency became extremely high and unexpected The equipment has become worn out and has to be replaced frequently. After investigating the cause of this situation,
It was confirmed that the mud particles changed their properties in a certain process in the distillation operation, for example, in the distillation process, etc., and the backwash was in an unsteady state in which the backwash could not be recovered to a predetermined state by being fixed in the filter passage. . Although the state of the mud particles whose properties have changed is not always clear, it is considered that the mud and water are closely related to each other during the distillation operation because the method of the present invention has substantially solved the problem. Similarly, the inventors of the present invention observed the steam stripped bottom oil by supplying the bottom oil (AR) from the atmospheric distillation to a vacuum distillation apparatus to separate it into a distillate oil and a bottom oil, A similar phenomenon was observed.

[0005]

SUMMARY OF THE INVENTION The present invention prevents solid particles in heavy oil from settling in the filter passage to rapidly increase the filtration resistance and to reduce the operating efficiency of the filter. An object of the present invention is to provide a pretreatment method for heavy oil that can be used.

[0006]

The method for pretreatment of heavy oil according to the present invention comprises performing dehydration treatment in advance when introducing heavy oil containing solid particles and water into a filter.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The heavy oil pretreatment method of the present invention comprises:
It is applied to heavy oils containing solid particles and also containing water. For example, it is applied to a heavy oil containing solid particles and condensed steam-condensed water. The heavy oil is not particularly limited, such as petroleum-based oil and coal-based heavy oil, but is preferably applied to petroleum-based oil. For example, a distillation residual oil obtained by distilling an oil containing a heavy component containing solid particles such as crude oil in a distillation column while blowing steam into the bottom is mentioned. Examples of such distillation residual oil include atmospheric residual oil obtained by introducing raw oil such as crude oil into a distillation column and performing atmospheric distillation while blowing steam, or obtained without contact with steam or with contact with steam. An example is a vacuum residual oil obtained by introducing the atmospheric residual oil into a distillation column and distilling it while blowing steam under reduced pressure. The crude oil introduced into the distillation column is preferably one that has been washed with water and subjected to electric desalination treatment in advance. Atmospheric pressure distillation of crude oil by such a steam blowing method gives an atmospheric residual oil containing solid particles and water and usually having a boiling point of about 350 ° C. or higher. Further, the atmospheric residual oil is decompressed, for example, an absolute pressure of 10 to 100 mmHg.
When distillation is carried out while blowing steam under a reduced pressure of a certain degree, a reduced pressure residual oil containing solid particles and water is similarly obtained.

The heavy oil is an oil containing solid particles containing at least one component having the same boiling point range as that of the atmospheric residual oil or the vacuum residual oil, in addition to the above-mentioned distillation residual oil. In addition, those containing water can also be targeted. For example, a heavy oil obtained by steam-treating an oil containing a heavy component obtained in a subsequent step in a petroleum refining plant, for example, a catalytic cracking step of a distillation residual oil, in the same manner as above.

There are no particular restrictions on the solid particles contained in the heavy oil to which the present invention is applied. For example, mud particles,
Examples include various solid particles derived from raw material oil such as crude oil such as metal particles and metal compound particles, rust particles derived from piping and the like, catalyst particles from a catalytic reaction step, and the like. Further, there is no particular limitation on the content or particle size of the solid particles. For example, depending on the origin of crude oil, oil collecting conditions, etc., the distillation residual oil obtained by distilling crude oil contains solid particles in an amount of about 10 to 500 ppm by weight, and the maximum particle diameter is about 100 μm. The present invention can be applied to any of them. The water content of the heavy oil to be subjected to the dehydration treatment is usually 500 to 700 p by weight in the distillation residual oil obtained by the distillation by the steam stripping method as described above.
It is about pm.

As a method for dehydrating the heavy oil containing water and solid particles as described above, a heating operation method, a depressurization operation method, an inert gas such as nitrogen, hydrogen, refinery off gas, etc. Any means such as a method by a contact operation with or a method by an adsorption operation can be used. One of these operations may be adopted, or two or more kinds of operations may be simultaneously adopted in one step, or a plurality of steps of different kinds or the same operation may be provided to connect in series or Can be used in combination in parallel. For example, when adopting two or more operations at the same time, operations such as heating the heavy oil to a predetermined temperature to bring it into contact with an inert gas, or bringing the heavy oil into contact with an inert gas under reduced pressure, etc. Is mentioned.

The water content of the heavy oil after the dehydration treatment depends on the kind of the target heavy oil, but is preferably 300 ppm by weight or less, more preferably 200 ppm by weight or less. The conditions such as the heating temperature, the degree of reduced pressure, the amount of inert gas supplied, and the treatment time may be appropriately selected so that the water content in the heavy oil falls within the above range. For example, when processing a distillation residual oil, the bottom temperature of the distillation column is 320 to 370 ° C., and the absolute pressure is 200 to 60.
If dehydration treatment is performed under the condition of 0 mmHg, the water content is 50 to
It can be dehydrated to about 150 ppm. 320-370 ° C
When the dehydration treatment is carried out by contact with an inert gas, the feed amount of the inert gas with respect to the treatment amount of the heavy oil per ton is preferably 0.1 to 1.0 m ³ . When performing the dehydration treatment of heavy oil by reducing the pressure, a steam ejector can be used as the pressure reducing device. In this case, the steam discharged from the ejector can be used as a steam source in a steam treatment process of heavy oil, for example, a steam source blown into a distillation column.
That is, since the steam blown into the distillation column can also be used as the steam for the reduced pressure generator, it is not necessary to newly provide a steam source for the reduced pressure generator. The heavy oil dehydrated to a predetermined water content by the dehydration treatment method of the present invention is then introduced into a filter. The filter is selected according to the purpose. For example, when the distillation residual oil is supplied to the demetallization reactor, a slit type filter having an opening of 25 μm is used. The filtration operation is usually performed at a temperature of 230 to 270 ° C,
It is carried out at a pressure of 10 to 30 kg / cm ² G.

[0012]

Examples 1 to 4 and Comparative Example 1 Filtration using bottom oil (AR) of an atmospheric distillation column obtained from a plant for refining crude oil in which Duri crude oil (80%) and Minas crude oil (20%) are mixed. The test was conducted. The main component of the particles in the mixed crude oil is SiO
₂ , Al ₂ O ₃ and Fe ₂ O ₃ , average particle size 0.5μ
m, and the maximum was 10 μm or less. AR is a bottom oil obtained by demineralizing the above mixed crude oil by washing with water, and cutting light fractions at the atmospheric pressure distillation column (column bottom oil temperature 350 ° C.) by a steam stripping method to a water content of about 500 ppm by weight. And 40 to 50 ppm by weight of particles in crude oil. A
For the dehydration treatment of R, AR was placed in an open container and heated by a throw-in type steam coil to perform dehydration. The water concentration was controlled by the holding time of the steam coil to prepare sample oils (Examples 1 to 4) having different water concentrations. About 500 weight pp
A filtration test was performed on the bottom oil (AR) of the atmospheric distillation column containing m water as it was (Comparative Example 1) and the samples of Examples 1 to 4. In the filtration test, a sample with a flow rate of 1 L / hr was pressurized to 20 Kg / cm ² G with a pump, and oil was passed through a wire mesh type filter of 8 mmφ with an opening of 17 μm and kept at 250 ° C. The inlet-outlet differential pressure was measured. Table 1 shows the oil passage time at which the differential pressure between the inlet and the outlet becomes 0.5 kg / cm ² .

[0013]

[Examples 5 and 6 and Comparative Example 2] Middle bottom Arabian heavy crude oil was subjected to vacuum distillation, and the bottom oil (VR) itself containing about 700 ppm by weight of water (Comparative Example 2) and Examples 1 to 4 thereof were used. A sample dehydrated in the same manner as in Example 5 (Example 5,
A filtration test was conducted on 6). The main components of the particles in this AR were FeS and NaCl, and the concentration was 35 ppm. The results are shown in Table 1.

[0014]

[Table 1]

As is clear from Table 1, as the water content in the heavy oil decreases, the oil passage time under a constant differential pressure condition at the inlet and outlet of the filter increases and becomes several times.

[0016]

According to the present invention, when a heavy oil containing solid particles and water, such as a heavy oil containing solid particles and treated with steam, is introduced into a filter, dehydration treatment is performed beforehand. By doing so, the oil passage time to the filter is increased, so the frequency of backwashing the filter is reduced, and the replacement of the oil passage / backwash switching device is significantly reduced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Nozaki 1-1-14, Minami Sanrokusho, Yokohama-shi, Kanagawa JGC Corporation Yokohama Office

Claims (5)

[Claims] 1. A pretreatment method for a heavy oil, which comprises performing a dehydration treatment in advance when introducing the heavy oil containing solid particles and water into a filter. 2. A heavy oil is obtained by introducing a raw material oil containing solid particles into a distillation column and distilling it while blowing steam under atmospheric pressure, or an atmospheric residue is obtained in the distillation column. The pretreatment method for a heavy oil according to claim 1, which is a vacuum residue obtained by introducing and distilling while blowing steam under a reduced pressure. 3. The method for pretreatment of heavy oil according to claim 1, wherein the water content of the heavy oil after dehydration treatment is 300 ppm by weight or less. 4. The dehydration treatment of heavy oil is performed by heating operation, depressurizing operation, contacting operation with an inert gas, or a combination of two or more of the operations, claim 1, claim 2 or claim 3. Pretreatment method for the heavy oil described. 5. The heavy-weight dewatering process according to claim 4, wherein a steam ejector is used as a depressurizing device when the heavy oil is dehydrated by depressurization, and steam discharged from the ejector is used as a steam source for blowing into a distillation column. Pretreatment method for quality oil.