JP2014169367A - Fuel oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel oil used in an internal combustion engine having a combustion chamber adapted to subject a fuel oil and a gas containing oxygen by 65 vol.% or more to combustion, which is low in an amount of exhaust gases such as NOX and THC.SOLUTION: A fuel oil used in an internal combustion engine having a combustion chamber adapted to subject a fuel oil and a gas containing oxygen by 65 vol.% or more to combustion, is characterized in that it comprises a gasoline base material of research octane value of 96.0 or less and a base material containing polycyclic aromatic hydrocarbon by 10 vol.% or more.

Description

The present invention relates to a fuel oil useful in an internal combustion engine that obtains power by burning fuel oil, an internal combustion engine using the fuel oil, and a pneumatic vehicle equipped with the internal combustion engine using the fuel oil.

In an internal combustion engine that obtains power by burning fuel oil such as gasoline, particularly an automobile engine, the fuel oil is mixed with air and subjected to combustion. Nitrogen molecules present in the air at 78.0% generate nitrogen oxides (NOX) such as 1 nitrogen monoxide, 2 nitrogen oxides and their dimers, 3 nitrogen oxides in the combustion process, which are ignored. There is a problem that it is discharged in an amount that cannot be done. Further, the nitrogen contained in the air acts to suppress the action of combustion by oxygen, so that unburned hydrocarbons remain in the combustion chamber and can be discharged as exhaust gas. In order to reduce the emission amount of NOX and total hydrocarbons (THC), a three-way catalyst and a NOX storage reduction catalyst are used.

However, in order to exert its effect, the three-way catalyst requires strict temperature control as well as the amount of fuel oil and air satisfying the stoichiometric air-fuel ratio (stoichiometry), and expensive such as platinum and rhodium. Need noble metals.

Engines that obtain power by burning hydrogen as fuel are known (for example, Patent Documents 1 and 2). In this engine, hydrogen is subjected to combustion together with oxygen and argon gas as a working gas, has a very high thermal efficiency, and does not use nitrogen, so there is no fear of exhausting NOX. However, since hydrogen is used, there is a high risk of explosion, handling is necessary, and it cannot be used easily.

JP-A-11-93681 JP 2009-68392 A

The present inventors have previously found that in the combustion of fuel oil, the amount of exhaust gas such as NOX and THC is reduced by using a gas containing 65% by volume or more of oxygen instead of conventional air. (Japanese Patent Application No. 2012-286842). An object of the present invention is to provide a fuel oil that is useful in an internal combustion engine that obtains power by such combustion, and that has a small amount of exhaust gas such as NOX and THC.

The present inventors have found that the above object is achieved when a fuel oil having a specific base material is subjected to combustion together with a gas containing 65% by volume or more of oxygen.

That is, the present invention relates to a fuel oil used in an internal combustion engine having a combustion chamber adapted to be combusted with a fuel oil and a gas containing 65% by volume or more of oxygen, and has a research octane number. The fuel oil comprising a gasoline base material of 96.0 or less and a base material containing 10% by volume or more of polycyclic aromatic hydrocarbons.
The present invention also relates to an internal combustion engine having a combustion chamber adapted to be combusted with a fuel oil and a gas containing 65% by volume or more of oxygen, wherein the fuel oil is used as the fuel oil. An internal combustion engine is provided.
The present invention also provides a pneumatic vehicle equipped with an internal combustion engine having a combustion chamber adapted to be combusted with a fuel oil and a gas containing 65% by volume or more of oxygen. A diesel powered vehicle using fuel oil is provided.

The fuel oil of the present invention has a small amount of exhaust gas such as NOX and THC when subjected to combustion with a gas containing 65% by volume or more of oxygen. Therefore, in an internal combustion engine that obtains power by such combustion, There is no need to use a three-way catalyst or NOX storage reduction catalyst. In addition, the internal combustion engine using the fuel oil of the present invention can be suitably used in vehicles such as pneumatic vehicles and automobiles.

It is a schematic diagram which shows the internal combustion engine system used in the Example.

The fuel oil of the present invention is used in an internal combustion engine having a combustion chamber adapted to be combusted with a gas containing 65% by volume or more of oxygen.

FIG. 1 is a diagram showing an example of a system including the internal combustion engine. The internal combustion engine 10 has a combustion chamber. In the combustion chamber, the fuel oil supplied from the fuel tank 1 is subjected to combustion together with the gas supplied via the preserver 5. The gas contains 65% by volume or more of oxygen in steady-state combustion. The gas preferably does not contain nitrogen from the viewpoint of suppressing the production of NOX.

The fuel oil of the present invention used in such an internal combustion engine includes a gasoline base material having a research octane number of 96.0 or less and a base material containing 10% by volume or more of polycyclic aromatic hydrocarbons. In addition, the said research method octane number (RON) is a value measured by JISK2280 "an octane number and a cetane number test method".

The gasoline base material having a research octane number of 96.0 or less may be any gasoline base material as long as this condition is satisfied. Specifically, light naphtha obtained by atmospheric distillation of crude oil, heavy naphtha obtained by atmospheric distillation of crude oil, desulfurized full-range naphtha obtained by desulfurizing naphtha fraction obtained by distillation of crude oil, light naphtha Desulfurized light naphtha desulfurized, desulfurized heavy naphtha desulfurized heavy naphtha, and addition of lower olefins to hydrocarbons such as isomerized gasoline and isobutane obtained by converting light naphtha to isoparaffin using an isomerizer (alkylation) From the modified gasoline obtained by the catalytic reforming method, desulfurized alkylate obtained by desulfurizing the alkylate, desulfurized alkylate obtained by desulfurization, hydrocarbons such as desulfurized isobutane and desulfurized lower olefin. Raffinate (sulfolan raffinate), a residue obtained by extracting sulfolan from a group, and decomposition obtained by catalytic cracking Sorin light fraction of light fractions of (light cracked gasoline) and reformate (light reformate) and the like. Of these, light naphtha, heavy naphtha, desulfurized full-range naphtha, desulfurized light naphtha, desulfurized heavy naphtha and isomerized gasoline are preferred. The amount of the gasoline base material having a research octane number of 96.0 or less is not limited, but is preferably 1% by volume or more, more preferably 3% by volume or more, and more preferably 5% by volume or more based on the total amount of fuel oil. Preferably, 10% by volume or more is more preferable, 99% by volume or less is preferable, 97% by volume or less is more preferable, 95% by volume or less is further preferable, and 90% by volume or less is more preferable.

The base material containing 10% by volume or more of the polycyclic aromatic hydrocarbon may be any base material as long as this condition is satisfied. Here, the polycyclic aromatic hydrocarbon is a hydrocarbon having two or more aromatic rings condensed with each other, specifically, a bicyclic aromatic hydrocarbon such as naphthalene, acenaphthene, acenaphthylene, anthracene, fluorene and phenanthrene. And aromatic hydrocarbons having 4 or more aromatic rings such as pyrene, fluoranthene and benzo [a] pyrene. Specific examples of the base material include a heavy fraction of reformed gasoline obtained by the catalytic reforming method (particularly a fraction of 160 ° C. or higher), and a heavy fraction of cracked gasoline obtained by the catalytic cracking method (particularly, , 160 ° C or higher), catalytic cracked kerosene, heavy fraction of catalytic cracked kerosene, catalytic cracked light oil, heavy fraction of catalytic cracked light oil, bicyclic aromatic hydrocarbons such as naphthalene, acenaphthene, acenaphthylene, anthracene , Aromatic hydrocarbon solvents containing tricyclic aromatic hydrocarbons such as fluorene and phenanthrene, aromatic hydrocarbons having four or more aromatic rings, and one or more polycyclic aromatic hydrocarbons (for example, Exxon Mobil Chemical) S200 (trade name) manufactured by the company). Among them, those which are liquid at normal temperature are preferable, and catalytic cracking kerosene, catalytic cracking light oil and the above aromatic hydrocarbon solvents are particularly preferable. As described above, the base material may be any base material as long as it contains 10% by volume or more of polycyclic aromatic hydrocarbons, but is preferably a polycyclic aromatic hydrocarbon. Is preferably a substrate containing 30% by volume or more of polycyclic aromatic hydrocarbons, more preferably a substrate containing 40% by volume or more of polycyclic aromatic hydrocarbons. . The upper limit of the polycyclic aromatic hydrocarbon content is 100% by volume, preferably 95% by volume. The amount of the base material containing 10% by volume or more of the polycyclic aromatic hydrocarbon is not limited, but is preferably 1% by volume or more, more preferably 3% by volume or more, more preferably 5% by volume based on the total amount of fuel oil. % Or more, more preferably 10% by volume or more, more preferably 99% by volume or less, more preferably 97% by volume or less, still more preferably 95% by volume or less, and still more preferably 90% by volume or less.

The distillation property of the fuel oil of the present invention is not particularly limited, but the initial boiling point (IBP) of distillation is preferably 21 ° C. or higher and 75 ° C. or lower, and 28 ° C. or higher and 65 ° C. or lower from the viewpoint of ensuring startability of combustion. Is more preferable, and 30 to 60 ° C. is more preferable. The 10 vol% distillation temperature (T ₁₀ ) is preferably 40 ° C. or higher and 85 ° C. or lower, more preferably 45 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 75 ° C. or lower, from the viewpoint of ensuring startability of combustion. Further preferred. The 50% by volume distillation temperature (T ₅₀ ) is not limited, but is preferably 130 ° C. or higher and 300 ° C. or lower.

The 90% by volume distillation temperature (T ₉₀ ) is preferably 240 ° C. or higher and 390 ° C. or lower, more preferably 240 ° C. or higher and 360 ° C. or lower, even more preferably 240 ° C. or higher and 330 ° C. or lower, and most preferably 240 ° C. or higher and 310 ° C. or lower. preferable. The 95% by volume distillation temperature (T ₉₅ ) is preferably 250 ° C. or higher and 430 ° C. or lower, more preferably 250 ° C. or higher and 400 ° C. or lower, further preferably 250 ° C. or higher and 380 ° C. or lower, and most preferably 250 ° C. or higher and 320 ° C. or lower. . The end point (EP) is preferably 260 ° C or higher and 450 ° C or lower, more preferably 260 ° C or higher and 410 ° C or lower, further preferably 260 ° C or higher and 390 ° C or lower, and most preferably 260 ° C or higher and 360 ° C or lower. The 90 vol% distillation temperature (T _90), the upper limit of 95 vol% distillation temperature (T ₉₅₎ and the end point (EP) is defined in terms of such a small amount of THC in the exhaust gas.

Initial distillation point (IBP), 10% by volume distillation temperature (T ₁₀ ), 50% by volume distillation temperature (T ₅₀ ), 90% by volume distillation temperature (T ₉₀ ), 95% by volume distillation temperature (T ₉₅ ) and end point (EP) are distillation properties measured by JISK 2254 "Petroleum products-Distillation test method".

The fuel oil of the present invention is preferably a hydrocarbon oil of 60% by volume or more, more preferably 80% by volume or more, still more preferably 90% by volume or more, further preferably 93% by volume to 100% based on the total amount of fuel oil. Includes volume%. The saturated hydrocarbon content, aromatic hydrocarbon content and olefinic hydrocarbon content in the hydrocarbon oil are not particularly limited, but preferred embodiments are described below.

The saturated hydrocarbon content is preferably 35% by volume or more, more preferably 40% by volume or more, and still more preferably 45% by volume or more from the viewpoint of ensuring startability of combustion. The olefinic hydrocarbon content is preferably 1% by volume or more and more preferably 5% by volume or more from the viewpoint of flame propagation characteristics.

From the viewpoint of combustion efficiency, the aromatic hydrocarbon content is preferably 5% by volume or more, more preferably 10% by volume or more, and further preferably 15% by volume or more. The upper limit is not limited, but is preferably 65% by volume or less, more preferably 60% by volume or less, and even more preferably 55% by volume or less.

In addition, the monocyclic aromatic hydrocarbon content in the hydrocarbon oil is preferably 35% by volume or less, more preferably 30% by volume or less, because fuel efficiency is good and the amount of THC in the exhaust gas is small. 27% by volume or less is more preferable, and the lower limit is preferably 0% by volume or more, more preferably 1% by volume or more, and still more preferably 3% by volume or more. The bicyclic aromatic hydrocarbon content in the hydrocarbon oil is preferably 25% by volume or less, more preferably 15% by volume or less, because fuel efficiency is good and the amount of THC in the exhaust gas is small. The lower limit is more preferable, and the lower limit is preferably 0% by volume or more, more preferably 1% by volume or more, and further preferably 3% by volume or more. The content of polycyclic aromatic hydrocarbons having 3 or more rings in the hydrocarbon oil is preferably 15% by volume or less and preferably 10% by volume or less because of good fuel efficiency and a small amount of THC in the exhaust gas. More preferably, it is more preferably 7% by volume or less, and the lower limit is preferably 0% by volume or more, more preferably 1% by volume or more, further preferably 3% by volume or more. . However, the content of polycyclic aromatic hydrocarbons of 2 or more rings is preferably 1% by volume or more, and more preferably 3% by volume or more.

The above saturated hydrocarbon content, aromatic hydrocarbon content, 1-ring aromatic hydrocarbon content, 2-ring aromatic hydrocarbon content, polycyclic aromatic hydrocarbon content of 3 or more rings and olefinic hydrocarbon content are all It is a value measured by the HPLC method defined in -5S-49-97.

The sulfur content of the fuel oil of the present invention is not limited at all. This is because the fuel oil of the present invention is used in the above-mentioned specific internal combustion engine, and as described above, the amount of exhaust gas such as NOX and THC is small, and therefore a catalyst such as a three-way catalyst is used. It is not necessary. In a conventional internal combustion engine, a catalyst such as a three-way catalyst is used to reduce the amount of exhaust gas such as NOX and THC. When the sulfur content in the fuel oil is high, the catalyst is deactivated. Oil does not require the use of such a catalyst, and therefore the sulfur content is not limited in any way. Preferably, the deterioration of the system of the internal combustion engine can be reduced, and the like, based on the total amount of fuel oil, is 2000 mass ppm or less, more preferably 500 mass ppm or less, and further preferably 200 mass ppm or less. More preferably, it is more preferably 80 ppm by mass or less, most preferably less than 20 ppm by mass, and the lower limit is not limited, but 0 ppm by mass.

The sulfur content is a value measured according to JIS K 2541 “Crude oil and petroleum products—Sulfur content test method” when the content is 1 mass ppm or more. When the content is less than 1 mass ppm, ASTM D4045-96 “ It is a value measured by “Standard Test Method for Sulfur in Petroleum Products by Hydrogenolysis and Rateometric Colorimetry”.

The method for producing the fuel oil of the present invention is not particularly limited as long as the gist of the present invention is not impaired. It can be produced using one or more gasoline base materials having a research octane number of 96.0 or less and one or more base materials containing 10% by volume or more of the polycyclic aromatic hydrocarbon described above.

In the production of the fuel oil of the present invention, an oxygen-containing compound may be further added. Examples of the oxygen-containing compound include ethers such as methyl tertiary butyl ether (MTBE) and ethyl tertiary butyl ether (ETBE), and alcohols such as methanol, ethanol, 1-butanol, 2-butanol and isobutanol. . The amount of the oxygen-containing compound in the fuel oil of the present invention is not limited, but is preferably 40% by volume or less, more preferably 20% by volume or less, further preferably 10% by volume or less, and further preferably 7% by volume. It is as follows.

The fuel oil of the present invention includes a colorant for identification, an antioxidant for improving oxidation stability, a metal deactivator, a corrosion inhibitor for preventing corrosion, and a fuel line for maintaining cleanliness. Additives such as a detergent and a lubricity improver for improving lubricity may be added.

The internal combustion engine in which the fuel oil of the present invention is used, in order to perform its start more stably, at the start (that is, at the start of combustion), nitrogen and an optional noble gas are added together with oxygen. It is preferred that the containing gas is supplied to the combustion chamber. The amount of oxygen is 10-50% by volume of gas, preferably 10-40% by volume, the amount of nitrogen is 50-90% by volume of gas, preferably 60-90% by volume, and the amount of rare gas is It is preferably 0 to 20% by volume, preferably 0 to 15% by volume. The noble gas means a group 18 element in the periodic table of elements, and is typically argon.

After starting the internal combustion engine, the proportion of oxygen in the gas can be increased gradually or stepwise, and when operation reaches a steady state (typically 10-30 seconds after the start) A gas containing 65% by volume or more of oxygen, preferably a gas containing 75-100% by volume of oxygen, more preferably a gas containing 85-100% by volume of oxygen, more preferably a gas containing 90-100% by volume of oxygen. Most preferably, by subjecting a gas consisting only of oxygen to combustion, stable operation can be continued and NOX emission can be suppressed. In conventional internal combustion engines that use air, nitrogen contained in a large amount acts in the action of suppressing the combustion of oxygen, so unburned hydrocarbons remain in the combustion chamber and are discharged as exhaust gas. In the internal combustion engine of the invention, since the gas contains 65% by volume or more of oxygen, the amount of unburned hydrocarbons can be reduced, and therefore, the emission amount of total hydrocarbons (THC) can be suppressed. Moreover, since there is little unburned hydrocarbon amount, combustion efficiency is high.

The gas when the operation reaches a steady state may contain nitrogen and / or a rare gas as long as the effects of the present invention are not impaired. The amount of nitrogen that can be included is 0 to 35% by volume of gas, preferably 0 to 15% by volume, and the amount of rare gas is 0 to 10% by volume, preferably 0 to 5% by volume of gas. Within these ranges, there is an effect of lowering the combustion temperature, and even if the gas contains nitrogen, the amount of NOx emitted is small.

The oxygen, nitrogen, and rare gas are preferably used so that the ratio of gas components at the start and thereafter can be adjusted as appropriate, and the pressure fluctuation can be reduced and gas can be stably supplied to the combustion chamber. As shown in FIG. 1, the gas is supplied from each gas cylinder to the combustion chamber. The supply of nitrogen may be performed using an air cylinder in addition to the nitrogen cylinder, or may be performed by natural suction. In FIG. 1, nitrogen, oxygen, and a rare gas (argon) are supplied from the air cylinder 2, the oxygen cylinder 3, and the argon cylinder 4 to the combustion chamber via the preserver 5.

In the internal combustion engine, since the gas subjected to combustion contains oxygen in an amount of 65% by volume or more, NOx emissions are significantly reduced, and therefore expensive three-way catalysts and nitrogen oxide storage reduction catalysts are used. There is no need. This leads to simplification and cost reduction of the internal combustion engine. However, the internal combustion engine in the present invention is not intended to use no catalyst at all, and uses a small amount of a three-way catalyst or other conventionally used catalyst (for example, an adsorbent) as necessary. May be.

The internal combustion engine in the present invention can include a reformer for reforming the fuel oil as necessary. Thereby, the heavy fuel oil with good combustion efficiency can be supplied to the internal combustion engine. In this case, the reforming of the fuel oil may be performed on the entire fuel oil, but is not necessarily required, and may be performed on only a part thereof.

Furthermore, in order to prevent knocking, the internal combustion engine can reduce the compression ratio to, for example, 8.5 or less and / or reduce the cooling water outlet temperature to, for example, 50 to 80 ° C. as necessary. . In order to prevent oxygen inhalation resistance, it is preferable to install a buffer bag that can expand and contract. In order to prevent backfire, it is preferable to use a low rotation range, not to reduce the suction negative pressure too much (for example, not to make it 400 mmHg or less), and / or adjust the valve clearance.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. Properties and the like of the hydrocarbon oil used in the examples are shown in Tables 1-2.

Examples 1-12
The fuel oil base materials shown in Tables 1 and 2 below were used in the amounts (volume%) shown in Tables 3 and 4 to produce fuel oils shown in Tables 3 and 4. The obtained fuel oil was used in the internal combustion engine system shown in FIG. 1 to measure NOX emissions and THC emissions. The results are shown in Tables 3-4. As the internal combustion engine 10, a 4-cycle 2-cylinder engine having a total displacement of 359 cc was used. The fuel oil was supplied from the fuel tank 1, and the gas was supplied from the air cylinder 2, oxygen cylinder 3, and argon cylinder 4 to the preserver 5, and then supplied to the combustion chamber of the internal combustion engine 10. The exhaust gas was treated with the oxidation catalyst 6 and then exhausted through the cooling pipe 7. The discharged gas was mainly argon gas and carbon dioxide, and water was discharged as a liquid.

The operation of the internal combustion engine was performed as follows. That is, at start-up, a gas containing oxygen, argon and nitrogen in amounts of 20.9 vol%, 0.9 vol% and 78.1 vol%, respectively, was supplied to the combustion chamber. After a lapse of 30 seconds from the start, it was confirmed that a steady state was obtained by visual observation, and the operation was continued for another 30 seconds. Thereafter, the gas composition was adjusted to 89.3 vol% oxygen and 10.7 vol% nitrogen. Continued. As a result, it was operated for 100 hours without any trouble. The rotation speed of the internal combustion engine was 3000 rpm, the compression ratio was 7.6, and the cooling water temperature was 60 ° C.

Measurement of NOx emission amount It was confirmed visually that the combustion was in a steady state and the rotational speed of an oscilloscope, and sampling of exhaust gas with a sampling bag was started after 5 to 10 seconds. After sampling for 10 seconds, the collected exhaust gas was immediately introduced into the NOX detector tube, and the amount of NOX was determined from the color change.

Ensure that the measuring <br/> combustion THC emissions has become a steady state at a rotation number of visual and oscilloscope, began collecting in the exhaust gas at the sampling bag after the 5 to 10 seconds. After sampling for 10 seconds, the collected exhaust gas was immediately introduced into the THC detector tube, and the amount of THC was determined from the color change.

Comparative Example 1
In Example 11, the operation was performed in the same manner as in Example 11 except that the gas supplied to the combustion chamber of the internal combustion engine 10 was only air at both the start and steady state. NOX emissions were 140 ppm and THC emissions were 400 ppm.

Comparative Example 2
In Example 11, a gas containing 70 volume% oxygen, 29 volume% nitrogen, and 0.9 volume% argon was used as the gas at the start. Backfire occurred and combustion became unstable, so the operation was stopped.

DESCRIPTION OF SYMBOLS 1 Fuel tank 2 Air cylinder 3 Oxygen cylinder 4 Argon cylinder 5 Preserver 6 Oxidation catalyst 7 Cooling pipe 10 Internal combustion engine

Claims (5)

A fuel oil used in an internal combustion engine having a combustion chamber adapted to be combusted with a fuel oil and a gas containing 65% by volume or more of oxygen having a research octane number of 96.0 or less The fuel oil comprising a gasoline base material and a base material containing 10% by volume or more of a polycyclic aromatic hydrocarbon. The fuel oil according to claim 1, wherein the sulfur content is 2000 mass ppm or less. The fuel oil according to claim 1 or 2, comprising an oxygen-containing compound. 4. An internal combustion engine having a combustion chamber adapted to be combusted with fuel oil and a gas containing 65% by volume or more of oxygen, wherein the fuel oil is any one of claims 1 to 3. The internal combustion engine, wherein the fuel oil is used. A pneumatic vehicle equipped with an internal combustion engine having a combustion chamber adapted to be combusted with fuel oil and a gas containing 65% by volume or more of oxygen, wherein the fuel oil is any one of claims 1 to 3. The diesel train in which the fuel oil according to claim 1 is used.

Images