JP2009235299A - A-type heavy oil composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an A-type heavy oil composition not generating clogging of a filter by wax in winter. <P>SOLUTION: The A-type heavy oil composition is excellent in low-temperature performance and combustibility, wherein k represented by formula (1) is at least 0.83 and not more than 1.05: k=926/ρ-0.210C-0.0467ln(3A) (1) (wherein, ρ represents the density at 15°C (kg/m<SP>3</SP>), C represents the 10% residual carbon (mass%), 3A represents the content of the aromatic having at least 3 rings (vol.%)). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an A heavy oil composition. More specifically, the present invention relates to a heavy oil composition A satisfying the JIS class 1 heavy oil standard that has sufficient performance for boilers for external combustion equipment in recent years, has excellent low-temperature fluidity, and is excellent in filter oil passing performance at low temperatures.

Conventionally, as a base material of A heavy oil composition, it is obtained from straight-run kerosene obtained from an atmospheric distillation apparatus of crude oil or desulfurized kerosene, straight-run light light oil or desulfurized light light oil, heavy light oil, and cracking equipment. Catalytic cracked light oil and direct degasified light oil obtained from a direct desulfurization apparatus are known. The conventional A heavy oil composition contains one or more of the above-mentioned base materials. In addition, it is manufactured by applying one or more kinds of normal pressure residual oil, direct desorption residual oil, and vacuum residual oil as residual carbon base materials. Moreover, additives such as a cetane number improver and a low temperature fluidity improver are blended with these A heavy oil compositions as necessary (see, for example, Non-Patent Document 1).
Seiichi Konishi, “Introduction to Fuel Engineering”, Saika Hanafusa, March 1991, p. 136-144

A fuel oil composition is widely used as fuel for external combustion equipment such as boilers, diesel engine equipment fuel for off-road use such as small fishing boats and construction machinery, and gas turbine equipment fuel.
Various combustion devices using the A heavy oil composition are provided with a filter having an opening of 5 to 250 μm in the fuel system for the purpose of removing foreign substances in the fuel oil. However, when such a combustion device is used in winter, the filter is likely to be clogged with wax precipitated from the A heavy oil composition.
Furthermore, with the recent increase in the output and fuel efficiency of boilers and engines used in the A heavy oil composition, there is an increasing demand for higher performance as the A heavy oil composition. When the A heavy oil composition is used as a fuel for these high-performance boilers, there may be a problem with combustibility such as deterioration in ignitability and increased generation of soot.

Therefore, in order to solve such problems, studies are being made to improve the low temperature fluidity of the A heavy oil composition. For the improvement of the low temperature fluidity, the amount of kerosene fraction is increased, the use of dewaxing base material, Formulation of quality oil (Patent Document 1), increase in residual oil (Patent Document 2), addition of a low-temperature fluidity improver (Non-Patent Document 2), and the like have been proposed.
JP 09-333583 A Japanese Patent Laid-Open No. 07-97581 Koji Nomura, “Science of Marine Fuel”, 1994, p. 164-166

However, the A heavy oil composition obtained by the above-described methods has room for improvement in the following points, and none of them is still sufficient to be put to practical use as the A heavy oil composition. That is, when kerosene fraction is blended to produce A heavy oil for cold district specifications, the blending amount is too large and the flash point becomes an obstacle, which is not effective from a safety standpoint. Even if a dewaxing base material is used, the amount of wax is too large to be used in a cold region, and the low temperature performance cannot be satisfied. Increased blending of heavy oil leads to deterioration of the wax precipitation point (cloud point). Increasing the amount of residual oil increases the amount of dust in the combustion gas. Furthermore, the performance of the low-temperature fluidity improver depends largely on the compatibility with the base material used, and the low-temperature performance of A heavy oil for cold regions cannot be improved simply by adding.
A heavy oil composition excellent in low-temperature performance often has a reduced amount of paraffin and poor combustibility. Also, when the calorific value per volume is high, the amount of paraffin is reduced and the combustibility is often deteriorated. Thus, an A heavy oil composition that satisfies both low temperature performance and combustibility at the same time has not been obtained.

A heavy oil composition that satisfies the JIS Class 1 heavy oil standard is used as boiler fuel and off-road diesel engine fuel, but in recent years, along with higher output and lower fuel consumption of the boiler used in A heavy oil composition, The filter used to remove foreign matters becomes finer, and the heavy oil composition A contains more heavy components than gasoline and kerosene, so wax precipitation at low temperatures may be a problem. Is growing. Wax precipitation at low temperatures may clog a filter for preventing contaminants in the fuel system, and in the worst case, fuel supply may not be possible. As a method for suppressing wax precipitation at low temperatures, a method of adding a fluidity improver is common, but under the actual severe winter conditions, a sufficient effect cannot be exhibited. Conventionally, a test based on a clogging point has been used to judge the filter clogging property at low temperatures. Although the low temperature fluidity is improved by adding a fluidity improver, this test method differs greatly from the actual use conditions because the cooling rate of the sample oil is rapidly cooled (about 40 ° C./hour). . It is known that the slower the cooling rate, the larger the precipitated wax and the clogging of the filter, and it is known that the evaluation based on the clogging point is insufficient (for example, Non-Patent Document 3). .
“Petroleum Society Standards, Standard Method for Testing Low Temperature Fluidity of Heavy Oil A (Simulation Method)”, JPI-5S-47-96, p. 6-7

In general, A heavy oil compositions with high calorific value per capacity and excellent low-temperature performance often have poor flammability due to the reduced amount of paraffin as described above, and A heavy oil composition that satisfies all these performances simultaneously. Things are desired.
Thus, an A heavy oil composition that satisfies all of the fuel efficiency, low temperature performance, and combustibility at the same time has not been obtained. An object of the present invention is to provide an A heavy oil composition that can withstand the use of high-performance boilers in recent years and does not cause clogging of the filter by wax in winter.

As a result of intensive studies to solve the above problems, the present inventors have found that by controlling the properties of the A heavy oil composition, the combustibility is high and the filter is not clogged with wax in winter. The present invention has been completed.
That is, the present invention relates to an A heavy oil composition excellent in low temperature performance and combustibility in which k shown in the following formula (1) is 0.83 or more and 1.05 or less.
k = 926 / ρ−0.210C−0.0467ln (3A) (1)
(In the formula (1), ρ represents a density at 15 ° C. (kg / m ³ ), C represents a 10% residual carbon content (mass%), and 3A represents a tricyclic or higher aromatic content (volume%).)

  The value of k shown in the present invention indicates that the larger the numerical value, the better the combustibility, but the lower the temperature performance is. Therefore, there is an optimum value for k in order to satisfy both the combustibility and the low temperature performance. That is, in the present invention, by controlling the value of k within a specific range, an A heavy oil composition that has high combustibility and does not cause clogging of the filter due to wax in winter is obtained.

  The present invention further relates to the A heavy oil composition, wherein the corrected clogging point is -8 ° C or lower.

  Furthermore, the present invention relates to the A heavy oil composition, wherein the ignition time is 1.8 seconds or less.

  According to the present invention, it is possible to obtain an A heavy oil composition that has good flammability, can withstand use in high performance boilers in recent years, and is excellent in low temperature performance that does not cause clogging of the filter due to wax in winter.

Hereinafter, the present invention will be described in detail.
In the A heavy oil composition of the present invention, k shown in the formula (1) needs to be 0.83 or more and 1.05 or less, and preferably 0.85 or more and 1.00 or less. When k shown in Formula (1) is smaller than 0.83, the ignitability deteriorates and the generation of soot is likely to increase in the boiler for the external combustion equipment. When k shown in the formula (1) is larger than 1.05, the low temperature performance is deteriorated, and the filter is easily clogged with wax in winter.

In the present invention, the density at 15 ° C. means a value obtained in accordance with JIS K 2249 “Crude oil and petroleum products—density test method and density / mass / capacity conversion table”.
In the present invention, the 10% residual carbon content means the residual carbon content (mass%) measured by JIS K 2270 “Crude oil and petroleum products—residual carbon content test method”.
In the present invention, an aromatic component of 3 or more rings means a value (volume%) obtained according to JPI-5S-49-47 “Hydrocarbon type test method—high performance liquid chromatograph method”.

In the A heavy oil composition of the present invention, the corrected clogging point is preferably −8 ° C. or lower. When the corrected clogging point of the A heavy oil composition is higher than −8 ° C., the filter is easily clogged with wax in winter.
Here, the corrected clogging point means a value measured by the correction method 4 described in the explanation of the Petroleum Institute Standard JPI-5S-47-96 “Testing Method for Low Temperature Fluidity of A Heavy Oil”.

In the heavy oil composition A of the present invention, the ignition time is preferably 1.8 seconds or less. When the ignition time of the A heavy oil composition is longer than 1.8 seconds, generation of soot is likely to increase in the boiler for external combustion equipment.
In the present invention, the ignition time is measured using a droplet combustion apparatus. Specifically, 1 μml of the sample is held at the tip of the quartz yarn, and a combustion furnace having a temperature of 750 ° C. is placed at atmospheric pressure and burned. The time from putting the combustion furnace to burning is the ignition time.

  A heavy oil base material used in the present invention includes a straight-run gas oil fraction obtained from an atmospheric distillation apparatus or a desulfurized gas oil fraction thereof, a straight-run kerosene fraction or a desulfurized kerosene fraction thereof, hydrocracked gas oil, hydrogenation Desulfurized kerosene, residual oil desulfurized gas oil fraction, hydrodesulfurized gas oil fraction or hydrorefined gas oil fraction, the normal paraffin content removed by extraction of normal paraffin gas fraction, heavy gas oil fraction, reduced pressure Examples include diesel oil obtained by desulfurizing diesel oil and fluid catalytic cracking kerosene. In the present invention, these may be used alone or in combination of two or more.

A residual carbon base material can be mix | blended with the A heavy oil composition of this invention.
The type of the residual carbon base material is not particularly limited, and examples thereof include atmospheric residual oil, residual oil desulfurized heavy oil, vacuum residual oil, slurry oil, and extract oil. These may be used alone or in combination of two or more. Use. Here, the atmospheric residual oil is a residual oil obtained by distilling crude oil at atmospheric pressure using an atmospheric distillation apparatus. The residual oil desulfurized heavy oil is a heavy oil obtained when a normal pressure residual oil or a vacuum residual oil is desulfurized in a residual oil desulfurization apparatus. The vacuum residue is a residue obtained by distilling atmospheric residue under reduced pressure using a vacuum distillation apparatus. Slurry oil is residual oil obtained from a fluid catalytic cracker. Extract oil is an aromatic component that is not suitable for lubricating oil among the fractions extracted from the vacuum distillation apparatus for lubricating oil raw material by solvent extraction.

The A heavy oil composition of the present invention needs to satisfy JIS Class 1 heavy oil standards. The JIS Class 1 heavy oil standard is a standard that satisfies “Class 1” defined in JIS K 2205 “Heavy oil”. Specifically, the flash point is 60 ° C. or higher, the pour point is 5 ° C. or lower, and the residual carbon content is 4% by mass. Hereinafter, it is necessary that the kinematic viscosity at 50 ° C. is 20 mm ² / s or less, the sulfur content is 2.0 mass% or less, the water content is 0.3 volume% or less, and the ash content is 0.05 mass% or less.

The flash point of the heavy oil composition A of the present invention needs to be 60 ° C. or higher of JIS Class 1 heavy oil standard, and preferably 62 ° C. or higher. When the flash point of A heavy oil composition is lower than 60 ° C., a problem is likely to occur in safety during handling.
In the present invention, the flash point means a value obtained in accordance with JIS K 2265 “Crude oil and petroleum products—flash point test method”.

  The pour point of the A heavy oil composition of the present invention needs to satisfy 5 ° C. or less, which is a JIS class 1 heavy oil standard. Furthermore, it is preferable that it is 2.5 degrees C or less from a viewpoint of low-temperature fluidity | liquidity. Here, the pour point means a pour point measured by JIS K 2269 “Pour point of crude oil and petroleum products and cloud point test method of petroleum products”.

  The residual carbon content in the heavy oil composition A of the present invention needs to satisfy 4 mass% or less, which is a JIS class 1 heavy oil standard. Furthermore, it is preferably 3% by mass or less, more preferably 2% by mass or less, from the viewpoint of reducing fine particles and PM and maintaining the performance of the exhaust gas aftertreatment device mounted on the engine. The residual carbon content here means a residual carbon content measured by JIS K 2270 “Crude oil and petroleum products—residual carbon content test method”.

The kinematic viscosity at 50 ° C. of the A heavy oil composition of the present invention is preferably 3.0 mm ² / s or less, and more preferably 2.8 mm ² / s or less. When the kinematic viscosity at 50 ° C. of the fuel oil composition is larger than 3.0 mm ² / s, the resistance in the fuel injection system increases, the injection system becomes unstable, and the concentrations of NOx and PM in the exhaust gas increase. End up.
The kinematic viscosity here means the kinematic viscosity measured by JIS K 2283 “Crude oil and petroleum products—Kinematic viscosity test method and viscosity index calculation method”.

  The sulfur content in the heavy oil composition A of the present invention needs to satisfy 2% by mass or less, which is a JIS class 1 heavy oil standard. Furthermore, from the viewpoint of reducing fine particles and PM, and from the viewpoint of maintaining the performance of the exhaust gas aftertreatment device mounted on the engine, it is preferably 1.5% by mass or less, and more preferably 1% by mass or less. A sulfur content here means the residual carbon content measured by JISK2541 "crude oil and petroleum products-sulfur content test method".

  The water content of the heavy oil A composition of the present invention needs to satisfy 0.3% by volume or less, which is a JIS class 1 heavy oil standard. Furthermore, from the viewpoint of adverse effects on the member, it is preferably 0.2% by volume or less, and more preferably 0.1% by volume or less. In addition, the water | moisture content said by this invention means the value measured by JISK2275 "moisture test method (crude oil and petroleum products)".

  The ash content of the heavy oil A composition of the present invention needs to satisfy 0.05 mass% or less, which is a JIS class 1 heavy oil standard. Furthermore, from the viewpoint of reducing fine particles and PM, the content is preferably 0.04% by mass or less, and more preferably 0.03% by mass or less. The ash content in the present invention means a value measured by JIS K 2272 “Crude oil and petroleum product ash content and sulfate ash test method”.

Although there is no restriction | limiting about the distillation property of A heavy oil composition of this invention, Usually, it is preferable to satisfy | fill the following property.
10 vol% distillation temperature (T10): 180-280 ° C
50 volume% distillation temperature (T50): 240-340 degreeC
90 volume% distillation temperature (T90): 280-380 degreeC
In the present invention, the distillation property means a value obtained according to JIS K 2254 “Petroleum products—Distillation test method”.

Although there is no restriction | limiting in particular about the cetane index of A heavy oil composition of this invention, From the point of combustibility, it is preferable that it is 30 or more, and it is more preferable that it is 35 or more. In the present invention, the cetane index means a value obtained in accordance with JIS K 2204-1992 “light oil”. That is, it is calculated by the following formula.
Cetane index (C) = 0.49083 + 1.06577 (X)-0.0010522 (X) ²
[X = 97.833 (logA) ² + 2.2088BlogA + 0.01247B ² -423.51logA-4.7808B + 419.59,
A: (9/5) [50% by volume distillation temperature (° C.) at 101.3 kPa (760 mmHg)] + 32
B: API degree (however, 50 vol% distillation temperature (° C.) at 101.3 kPa (760 mmHg) is measured according to JIS K 2254 “Petroleum products-distillation test method”, and API degree is JIS K 2249 “crude oil and petroleum Calculated from the density at 15 ° C. by “Product-Density Test Method and Density / Mass / Capacity Conversion Table”)]

  Although there is no restriction | limiting in particular about CFPP (clogging point) of A heavy oil composition of this invention, Since it is excellent in the point of prevention of filter clogging by wax in winter, it is preferable that it is -3 degrees C or less, and -5 It is more preferable that the temperature is not higher than ° C, and it is most preferable that the temperature is not higher than -7 ° C. In the present invention, CFPP means a value obtained in accordance with JIS K 2288 “Diesel Oil—Clogging Point Test Method”.

  Although there is no restriction | limiting in particular about the nitrogen content of A heavy oil composition of this invention, In order to reduce the harmful substance in waste gas, it is preferable that it is 0.02 mass% or less, and it is 0.015 mass% or less. Is more preferable, and it is most preferable that it is 0.01 mass% or less. In the present invention, the nitrogen content means a value representing a value obtained according to JIS K 2609 “Crude oil and petroleum products—nitrogen content test method”.

  Moreover, an additive can be mix | blended with the A heavy oil composition of this invention as needed. Various additives such as cetane number improvers, antioxidants, stabilizers, dispersants, metal deactivators, microbial disinfectants, auxiliary agents, antistatic agents, discriminating agents, colorants, etc. These additives can be added as appropriate. Among these, it is preferable to add a fluidity improver because it is excellent in the effect of preventing filter clogging by wax in winter. As the fluidity improver, for example, polymer-type additives such as ethylene-vinyl acetate copolymer and ethylene-α-olefin copolymer, oil-soluble dispersant-type additives, and alkersuccinic acid can be used. Moreover, although there is no restriction | limiting about the addition amount of a fluid improvement agent, It is preferable that it is 0.001-0.1 mass% on the basis of A heavy oil composition whole quantity, and is 0.01-0.05 mass%. It is more preferable.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[Examples 1-2 and Comparative Examples 1-2]
Table 1 shows the properties of the A heavy oil compositions of Examples 1-2 and Comparative Examples 1-2. About each sample oil (each composition), low temperature fluidity performance evaluation and flammability performance evaluation were performed by the following method. The results are shown in Table 2.

(Low temperature fluidity performance evaluation)
A 20 L pail can was prepared as a sample container, and a hole into which the sample suction tube was inserted was provided on the top surface of the pail can. The hole was formed at the midpoint of a straight line connecting the center of the upper surface and the point on the outer periphery. On the other hand, a copper tube having an outer diameter of 10 mm was prepared as a sample suction tube, and one end of the copper tube was connected to the inlet of a filter (Nepon Corporation, code No. 120267) via a silicon rubber tube. Moreover, the outlet of the filter was connected to a suction pump through a copper tube. As the suction pump, a pump capable of adjusting the oil flow rate within a range of 1 to 10 L / hr was used.
Next, about 15 L of a sample (A heavy oil composition) having a temperature of 20 to 25 ° C. is put in the above-mentioned pail can, a lid with a sample suction tube is put in the hole on the top surface of the pail can, and then the pail can and the filter are cooled to low temperature The pump was accommodated in a thermostat, the pump was driven, and the pump pressure was adjusted so that the oil flow rate was 9.5 ± 0.2 L / hr. As the low-temperature thermostat, a thermostat equipped with a program temperature adjusting function and capable of cooling to −30 ° C. or less within a temperature accuracy of ± 0.5 ° C. was used. After the pail can and the filter were accommodated in the low-temperature thermostatic chamber, the inside of the low-temperature thermostatic chamber was cooled with a predetermined temperature profile, and the suction pump was driven. More specifically, the sample was cooled from a temperature 8 ° C. higher than the cloud point of the sample to a predetermined temperature at a cooling rate of 1 ° C./hr. The temperature was held for 3 hours, and the oil passage limit was determined by measuring the pressure with a pressure gauge. Judgment of the oil passage limit is accepted when the differential pressure is 33 kPa (250 mmHg) or less during oil passage for 60 minutes at the holding temperature, and is rejected when it exceeds 33 kPa, and held at 1 ° C intervals until it fails. The test was repeated at a lower temperature. The highest temperature (clogging temperature) at which the judgment was rejected was used as an index for evaluating the low temperature performance. In addition, the sample was replaced with new oil for each test. A clogging temperature of −11 ° C. or lower was judged good (◯), and a temperature of −10 ° C. or higher was judged bad (×). The obtained results are shown in Table 2.

(Flammability performance evaluation)
The combustion performance was evaluated by measuring the burning rate. Fuel with a low combustion rate adversely affects the exhaust gas of boilers for external combustion equipment, and is a major cause of trouble in recent high performance boilers.
The boiler flammability was evaluated using a droplet combustion evaluation device. A sample of 1 μml is held at the tip of the quartz yarn, and a combustion furnace at atmospheric pressure and temperature of 750 ° C. is covered to burn the sample. The burning rate was obtained by video analysis of the amount of change in the sample radius during burning. When the combustion speed is low, soot is likely to be generated in boiler combustion. A burning rate of 0.85 mm ² / s or more was judged as good (◯), and a value of less than 0.85 mm ² / s was judged as bad (x). The obtained results are shown in Table 2.

  As is apparent from the results in Table 2, the A heavy oil compositions of Examples 1 and 2 according to the present invention are both excellent in combustibility, have sufficient performance for recent high performance engines, and have excellent low temperature performance. It turns out that it is excellent in filter oil passing performance.

Claims (3)

A heavy oil composition excellent in low temperature performance and combustibility, wherein k shown in the following formula (1) is 0.83 or more and 1.05 or less.
k = 926 / ρ−0.210C−0.0467ln (3A) (1)
(In the formula (1), ρ represents a density at 15 ° C. (kg / m ³ ), C represents a 10% residual carbon content (mass%), and 3A represents an aromatic content (volume%) of three or more rings.)   The heavy oil composition according to claim 1, wherein the corrected clogging point is -8 ° C or lower.   The heavy fuel oil composition according to claim 1 or 2, wherein the ignition time is 1.8 seconds or less.