JPH0251476B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to middle distillate fuel oil compositions with improved flowability. A method of mixing kerosene fractions is effective for improving the low-temperature fluidity of middle distillate fuel oil. However, in recent years,
As the demand for kerosene as a jet fuel and household fuel has increased, attempts have been made to reduce the amount of kerosene mixed with middle distillate fuel oil as much as possible and instead add pour point depressants such as low molecular weight ethylene copolymers. being done. However, the pour point depressants proposed in the past have often not had the ability to substantially lower the cryogenic filter plugging point (CFPP). According to Japanese Patent Publication No. 54-19406 and Japanese Patent Application Laid-Open No. 54-155204, it is stated that CFPP can be lowered when certain polar compounds are added to middle distillate fuel oil together with the pour point depressant. It is also stated that when the polar compound is not used in combination with a pour point depressant, it has almost no effect on lowering CFPP. However, there are many types of middle distillate fuel oils, and it has been found that there are some that do not reduce CFPP at all even when these proposed technologies are applied. The unpredictability of the effect of fuel oil on fluidity improvers is explained in the aforementioned Japanese Patent Publication No. 54-19406.
This is also suggested in the specification of No. The present inventors investigated additives that lower the CFPP of middle distillate fuel oil, which is ineffective even when applying the proposed technology, and found that certain primary aliphatic alcohols and fatty acids are effective. I came to the conclusion. And such additives, surprisingly,
When the polymeric pour point depressant disclosed in the above proposal and whose presence is essential is present,
It has also been found that, contrary to the teaching of the proposal, the effect is actually reduced. The present invention has an initial boiling point of 175 to 240℃ and a 90% distillation temperature.
300~360℃, difference between 90% distillation temperature and initial boiling point is 150℃
Hereinafter, a middle distillate fuel oil (A) with an end point of 380°C or less and a pour point of -10 to +5°C, and an additive selected from the group consisting of a fatty acid primary alcohol having 22 to 30 carbon atoms and a fatty acid having 22 to 30 carbon atoms The present invention relates to a fuel oil composition comprising an effective amount of agent (B). The middle distillate fuel oil (A) targeted by the present invention has an initial boiling point of
175-240℃, 90% distillation temperature 300-360℃, difference between 90% distillation temperature and initial boiling point is 150℃ or less, preferably 140℃
Hereinafter, typical light oils sold in Japan, which have an end point of 380°C or lower, for example 345°C or higher, and a pour point of -10 to +5°C, fall under this category. The properties of such fuel oil are slightly different from the European and American light oils used in the experiments in the above-mentioned publication, and due to these differences, the effect exerted by the additives will be different. The additive according to the invention is selected from aliphatic primary alcohols having 22 to 30 carbon atoms and fatty acids having 22 to 30 carbon atoms. More specifically, examples of the alcohol include n-docosyl alcohol, n-tetracosyl alcohol, n-hexacosyl alcohol, n-octacosyl alcohol, and n-triancotyl alcohol. .
Among these, those having 22 to 26 carbon atoms are particularly preferred. The fatty acids include behenic acid, n-tricosanoic acid, lignoceric acid, n-
Examples include pentacosanoic acid, cerocylic acid, n-heptacosanoic acid, montanic acid, n-nonacosanoic acid, and melisic acid. Among these,
Particularly preferred are those having 22 to 26 carbon atoms. Even if an aliphatic primary alcohol or fatty acid having a smaller or larger carbon number is used instead of these aliphatic primary alcohols or fatty acids, the CFPP of the fuel oil will hardly be lowered. However, aliphatic primary alcohols with 11 to 21 carbon atoms and 16 carbon atoms
Fatty acids having 22 to 30 carbon atoms are not effective on their own, but aliphatic primary alcohols having 22 to 30 carbon atoms and aliphatic primary alcohols having 22 to 30 carbon atoms, which are essential additives of the present invention,
Since it exhibits a synergistic effect when used in combination with 30 fatty acids, the lower limit of the effective amount of the essential additive can be reduced by using these together. The effective amount of additive used in the present invention varies depending on the type of additive and the type of fuel oil. If the amount of additive used is too small, the improvement effect will not be sufficient, but if the amount of additive used is too large, the effect of addition may not be substantially recognized, so it is necessary to select an effective amount of addition. There is. In general, for 100 parts by weight of fuel oil, the effective amount is for an aliphatic primary alcohol having 22 to 30 carbon atoms.
0.0005 to 0.05 parts by weight, preferably 0.001 to 0.05 parts by weight
0.3 parts by weight, for fatty acids with 22 to 30 carbon atoms,
0.001 to 0.1 parts by weight, preferably 0.005 to 0.1 parts by weight
Within the range of 0.05 parts by weight. In addition, when an aliphatic primary alcohol having 11 to 21 carbon atoms is used together with these additives, a fatty acid having 16 to 21 carbon atoms is used in combination with 0.05 parts by weight or less, for example 0.0005 to 0.05 parts by weight, per 100 parts by weight of fuel oil. If so, fuel oil
It is preferably used in an amount of 0.1 part by weight or less, for example in the range of 0.01 to 0.1 part by weight, per 100 parts by weight. It is preferable not to add ethylene/α-olefin copolymer or ethylene/vinyl acetate copolymer, which are generally known as pour point depressants, to the fuel oil composition of the present invention. This is because the presence of such a pour point depressant inhibits the effect of adding the additive. Next, an example will be explained. Example CFPP was measured when various additives were blended with 100 parts by weight of fuel oil. The properties of the fuel oil used are shown in Table 1, and the decrease in CFPP relative to the raw fuel oil is shown as ΔCFPP in Table 2. In addition, Table 3 shows △CFPP when a low molecular weight ethylene-propylene copolymer (ethylene content 79 mol%, number average molecular weight 4800), which is conventionally known as a pour point depressant, is added to the feedstock fuel oil. Indicated. Furthermore, CFPP
is Journal of the Institute Petroleum vol.52,
Measurement was performed according to the method described in No. 10.

【table】

【table】

[Table] In Tables 2 and 3, △CFPP
represents (Fuel oil blank CFPP) - (Fuel oil CFPP with additives added), where a positive value indicates an effective value, a negative value indicates an adverse effect,
0 indicates no effect.

Claims (1)

[Claims] 1 Initial boiling point 175-240℃, 90% distillation temperature 300-360
℃, the difference between the 90% distillation temperature and the initial boiling point is 150℃ or less, the final point is 380℃ or less, the pour point is -10 to +5℃, a middle distillate fuel oil A, and an aliphatic primary alcohol having 22 to 30 carbon atoms; A fuel oil composition comprising an effective amount of additive B selected from the group consisting of fatty acids having 22 to 30 carbon atoms.