JP3384423B2 - Middle distillate composition with improved low temperature fluidity - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a middle distillate composition having improved low temperature fluidity, and more specifically, to low temperature fluidity which is stably improved without using an expensive fluidity improver. The present invention relates to a middle distillate composition that enables an increase in production of middle distillates.

[0002]

2. Description of the Related Art In recent years, kerosene, light oil, and heavy fuel oil A (JIS K 2205-19) have become popular with the spread of large-scale household heating equipment, diversification of uses such as agriculture, and increase of diesel vehicles.
The demand for so-called middle distillates such as heavy oil (Type 1 specified in 80) has increased. On the other hand, the demand for heavy oil has decreased due to the conversion of fuels from thermal power plants to coal, LPG, etc. Under these circumstances, in order to meet the demand for the above middle distillates, the heavy gas oil fractions that were previously contained in heavy fuel oils are converted to middle distillates by cutting up the light gas oils or mixing the heavy gas oils. It is desirable to increase the production of middle distillates by including them. However, when the heavy gas oil fraction is included in the middle distillate, the wax content in the middle distillate increases and the low temperature fluidity deteriorates. Therefore, it is practically difficult to use such a middle distillate as it is as a fuel oil in the cold or in the cold district, and in order to increase the production of the middle distillate by the above method, low temperature fluidity is required. It was necessary to improve. As a method for improving the low temperature fluidity of the middle distillate, for example, JP-A-61-58116 and JP-A-HEI-3.
There is a method of adding a fluidity improver as described in JP-A-152190. However, such a method requires an additive purchase cost and a cost for constructing the additive facility, resulting in an increase in the cost of the middle distillate. Further, Japanese Patent Laid-Open No. 58-149991 discloses that
Focusing on the heavy oil added so that the% residual carbon content becomes 0.2% by weight or more, CFPP (by adding the heavy oil having the asphaltene content or the residual carbon content above a certain value) COLD FILTER PLUGGI
NG POINT OF DISTILLATE FU
Although it is described that the ELS) is lowered, it is still difficult to stably improve the low temperature fluidity of the middle distillate by this method.

[0003]

SUMMARY OF THE INVENTION The present invention has been made under the above circumstances, and by adding an inexpensive heavy oil to the middle distillate, it is possible to stabilize without using an expensive fluidity improver. It is an object of the present invention to provide a middle distillate composition having improved low temperature fluidity.

[0004]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a middle distillate having a specific n-paraffin concentration of 26 to 30 carbon atoms is
10% residual carbon content of 0.2 to 1.0 % by weight,
It has been found that by adding a heavy oil having a specific composition, it is possible to stably provide a middle distillate composition having improved low temperature fluidity without using an expensive fluidity improver. The present invention has been completed based on such findings. That is, the present invention is an intermediate fraction containing 0.05-0.35 mol% of n- paraffins 26-30 carbon atoms in a concentration in terms of n- paraffins having a carbon number of 26, Ass
Falten content 0.5 to 6.0% by weight, residual carbon content 1.0
~ 9.0 wt% and asphaltene content / residual carbon content of heavy oil of 0.2-1.5, 10% residual carbon content of 0.2-1.0 wt% The present invention provides a middle distillate composition characterized by being added as described above.

The present invention will be described in more detail below. As the middle distillate contained in the middle distillate composition of the present invention,
Light straight-run light oil (LGO), Light desulfurized light oil (DGO), Heavy straight-run light oil (HGO), Catalytic cracking light oil (LCO), Direct desulfurized light oil (DSGO), Indirect desulfurized light oil (VHLGO),
Each base material such as hydrocracked gas oil (HCGO) and kerosene (KERO) can be used alone or in combination. Each of the above-mentioned base materials can be prepared by a usual method, and the following properties can be generally used. Base material Distillation range (° C) LGO 140 ~ 390 DGO 140 ~ 390 HGO 200 ~ 600 LCO 150 ~ 380 DSGO 140 ~ 400 VHLGO 140 ~ 390 HCGO 140 ~ 390 KERO 140 ~ 280

In the present invention, the middle distillate composed of the above base material is composed of n-paraffin having 26 to 30 carbon atoms and 26 carbon atoms.
Roh n- paraffins concentration in terms of (hereinafter referred to as "C ₂₆ n- paraffins concentration in terms of") containing 0.05 to 0.35 mole percent. When the C ₂₆ n-paraffin conversion concentration deviates from the above range, the fluidity improving effect is insufficient. From the viewpoint of improving the fluidity, the C ₂₆ n-paraffin conversion concentration is 0.
It is preferably from 1 to 0.3 mol%. In the present invention, the C ₂₆ n-paraffin conversion concentration is determined by the following method. % By weight, obtained by gas chromatography
Each n-paraffin content represented by
86, Vol. 65, December, 1647-1
It is converted to a mol% display using the method described on page 652. FUEL, 1986, Vol. 65, Decemb
er, the equation (3) described on page 1649 is used to calculate the conversion factor (F ₁ ) of each n-paraffin into the n-paraffin concentration having 26 carbon atoms. However, r = 26, T = 2
73.2. The content (mol%) of n-paraffin having 26 to 30 carbon atoms is converted into the concentration of n-paraffin having 26 carbon atoms, and the C ₂₆ n-paraffin conversion concentration (mol%) is determined by the following formula.

[0007]

[Equation 1] Here, CN ₂₆ represents a C ₂₆ n- paraffins concentration in terms (mol%), also, N _i is the content of n- paraffins i carbon atoms (molar%), F _i is the i carbon number n- The conversion coefficient for the n-paraffin concentration of C26 paraffin is shown.

In the composition of the present invention, heavy oil having a ratio of asphaltene content to residual carbon content of 0.2 to 1.5 is added to the above-mentioned middle distillate so that 10% residual carbon content becomes a predetermined amount. The heavy oil added here is, for example, heavy oil such as normal pressure residual oil, reduced pressure residual oil, direct desulfurized heavy oil, asphalt, cracked residual oil, and extract in the production of lubricating oil. Examples thereof include oil and the like or a mixture thereof. In the present invention, these heavy oils can be used alone or in combination. As the heavy oil, one having a ratio of asphaltene content to residual carbon content (asphaltene content / residual carbon content) within the range of 0.2 to 1.5 is used, and the ratio is 1.5. If it exceeds the above range, the generation of sludge in the middle distillate increases, which is not preferable. From this point, in the present invention, the ratio of the asphaltene content to the residual carbon content is preferably 0.2 to 1.2. Further, the above heavy oil has an asphaltene content and a residual carbon content of 0.5 to 0.5, respectively.
It contains 6.0% by weight and 1.0 to 9.0% by weight . If any of A Sufa <br/> gluten content and residual carbon content may be outside the above lower limit may flowability improving effect becomes small and when departing from the upper limit to the formation of sludge is increased There is. The heavy oil is added to the middle distillate so that the 10% residual carbon content in the final composition is 0.2 to 1.0% by weight. If this value exceeds 1.0% by weight, the generation of sludge is also increased, which is not preferable. In addition to this point, when considering the effect of improving fluidity, the above 10%
The residual carbon content is preferably added so as to be 0.2 to 1.0% by weight.

In the present invention, the "asphaltene content" means a heavy component which is insoluble in n-heptane and soluble in toluene, and is IP TEST METHOD IP 14
3/84 "ASPHALTENS PRECIPITA
TION WITH NORMAL HEPTANE "
It can be measured by the method described in. In addition, "residual carbon content" refers to the carbonaceous material that remains in the crucible after putting heavy oil in the crucible, heating it with air cut off, and steaming it, "10% residual carbon content" Means a value obtained by measuring the residual carbon content by distilling the middle distillate composition to 90% and distilling it to 90%, and using 10% remaining in the distillation flask as a sample. This residual carbon content and 10% residual carbon content are
Both can be measured according to JIS K 2270-1985 "Crude oil and petroleum product residual carbon content test method (Conradson method)".

In the present invention, the above middle distillate composition is
For example, when the minimum temperature is lowered to about -10 ° C, the cloud point is preferably 5 ° C or lower, and the CFPP and the pour point are each preferably -10 ° C or lower. Cloud point, CFP
If either P or the pour point is higher than the above range, practical problems such as wax settling, clogging of strainer, and solidification of fuel may occur. In addition, additives such as a fluidity improver and a combustion aid may be added to the middle distillate composition of the present invention, if necessary, within a range that does not impair the object of the present invention.

[0011]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Examples 1 to 7 and Comparative Examples 1 to 5 A middle distillate having the properties and components shown in Table 1 was added to a heavy oil having the properties and components shown in Table 2 with a 10% residual carbon content of 0.21. A fuel oil was prepared by adding so that the fuel oil would be in a weight percentage. Each of the obtained fuel oils was subjected to a simulation test shown below to examine the effect of improving low temperature fluidity.
The results are shown in Table 3.

Simulation Test As shown in FIG. 1, a simulation test device simulating a house warmer was manufactured, and the low temperature fluidity of the middle distillate was evaluated by the following operation. That is, in the case of greenhouse cultivation, when the low-temperature fluidity of the fuel supplied to the house warm air fan is poor, the strainer and fuel piping of the warm air fan are blocked by the deposited wax, the fuel supply is cut off, and the flame disappears. During cold weather such as in winter, or in cold regions, damage such as the destruction of crops overnight occurs. in this way,
In view of the fact that the fuel for a house is required to have excellent low temperature fluidity, the effect of improving low temperature fluidity was investigated by the above-mentioned simulation test. Collect 15 liters of sample in a 20 liter sample container 1. The fuel system is connected, the low temperature chamber 2 is cooled to the test temperature at a rate of 1 ° C./hour, and when the test temperature is reached, the sample and the low temperature chamber are left to stand until the temperature difference becomes within 2 ° C. The fuel pump 6 is driven, and the fuel is strained (10
Oil (0 mesh) 4 at a flow rate of 9.5 liters / hour for 1 hour. If the strainer is clogged with wax, the strainer outlet pressure becomes negative. Therefore, if the pressure at the outlet of the strainer after 1 hour is -200 mmHg or less, it is judged as fail, and if it exceeds this pressure, it is judged as pass. Replace the sample and repeat the above test at a temperature 2 ° C lower in the case of pass and 2 ° C higher in the case of fail to find the highest temperature at which the fail appears. And The difference between the oil passage limit temperature of the middle distillate before adding the heavy oil and the oil passage limit temperature of the product after adding the heavy oil was evaluated as the fluidity improving effect (° C).

Each characteristic was measured as follows. * 1 Density: Measured according to JIS K 2249. * 2 Distillation properties: Measured according to JIS K 2254. * 3 Cloud point: measured according to JIS K 2269. * 4 CFPP: Measured according to JIS K 2288. * 5 Pour point: Measured according to JIS K 2269.

* 6 C ₂₆ n-paraffin conversion concentration: Calculated by the above formula (1). The content (% by weight) of each n-paraffin is the gas chromatograph GC- manufactured by Shimadzu Corporation.
9A and Chromatopack 3A data processor were used and measured under the following conditions. Column: J & W DB-1 mega bore column 60m (3
0m column 2 connection) Column temperature; 100-300 degreeC (temperature rising at 5 degreeC / min) Carrier gas; Helium injector temperature; 340 degreeC Detector; Hydrogenation flame ionization detector (FID) Using the said data processor, In the obtained gas chromatogram, the total area (S) above the baseline and n-
The area (P _i ) of the portion above the line connecting the valleys of the paraffin peak was obtained, and the n-paraffin content (% by weight) of carbon number i was calculated by the formula (P _i / S) × 100. . * 7 Kinematic viscosity: Measured according to JIS K 2283. * 8 Sulfur content: Measured according to JIS K 2541. * 9 Asphaltene content: IP TEST MRTH
OD IP 143/84 "ASPHALTENS P
RECIPITATION WITH NORMAL
It was measured by "HEPTANE". * 10 Residual carbon content: Measured in accordance with JIS K2270.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

According to the present invention, by adding an inexpensive heavy oil to the middle distillate, the middle distillate composition in which the low temperature fluidity is stably improved without using the expensive fluidity improver. As a result, it is possible to increase the production of middle distillates by cutting up light gas oil or mixing heavy gas oil.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a simulation device used in an example.

[Explanation of symbols]

1: Sample container 2: Cold storage 3: Fuel piping 4: Strainer 5: Negative pressure gauge 6: Fuel pump 7: Sample receiver

Claims (3)

(57) [Claims] 1. The concentration of n-paraffin having 26 to 30 carbon atoms converted to n-paraffin having 26 carbon atoms is 0.05 to.
The middle distillate containing 0.35 mol% has an asphaltene content of 0.
5 to 6.0% by weight and residual carbon content of 1.0 to 9.0% by weight
And having a ratio of asphaltene content to residual carbon content of 0.
2 to 1.5 heavy oil with 10% residual carbon content of 0.2 to
A middle distillate composition having improved low-temperature fluidity, which is added so as to have a value within a range of 1.0% by weight . 2. The middle distillate is at least a fraction selected from light straight-run gas oil, light desulfurized gas oil, heavy straight-run gas oil, catalytically cracked gas oil, direct desulfurized gas oil, indirect desulfurized gas oil, hydrocracked gas oil and kerosene. one middle distillate composition according to claim 1 Symbol placement is. 3. A heavy oil, atmospheric residue, vacuum residue, direct desulfurization fuel oil, asphalt, decomposed residual oil extract in the lubricating oil manufacture and in the claims 1 or is at least one selected from a mixture thereof middle distillate composition according to 2.