JP2003277774A - Reformed fuel obtained by reforming heavy oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reformed fuel for combustion equipment, obtained by removing vanadium in a heavy oil in a technique for producing a reformed oil by bringing a heavy oil into contact with a supercritical or subcritical water. <P>SOLUTION: A heavy oil is brought into contact with a supercritical or subcritical water in the presence of an oxidizing agent to reform it through hydrothermal reaction and to subject vanadium to elimination reaction. Vanadium oxide released is removed later from the liquid by an acceptor to produce a fuel having a vanadium content of 0.5 ppm by weight or lower. Accordingly, a metal possibly causing corrosion is selectively removed from a heavy oil so that the whole quantity of a hydrocarbon in a heavy oil can be converted into a fuel and burned. Thus, a low-cost heavy oil can be efficiently used as a fuel for combustion equipment, and the running cost can be reduced, without the necessity for adding equipment for environmental protection or the cost of installation for preventing corrosion. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reformed oil obtained by reforming a heavy oil by contacting it with supercritical water or subcritical water,
Particularly, it relates to a reformed oil suitable for use as a fuel for a gas turbine or a boiler.

[0002]

2. Description of the Related Art Oil produced for various purposes by refining crude oil is divided into light oil such as naphtha, gasoline, kerosene, and light oil, and heavy oil such as heavy oil, light cycle oil (LCO), and asphalt. . Fuel for cars and aircraft is limited to light oil, and for boilers for power generation, gas turbines, diesel engines, etc.
Relatively light oils such as kerosene and special heavy oil A (fuel desulfurized from heavy oil A) are used. Heavy oil is used as an energy source only for some power generation boilers, or marine diesel and boilers. A,
Heavy oils such as B and C heavy oils contain a larger amount of metals such as sulfur, alkali metals, vanadium, and nickel as components than light oils, and these metals contain molten salt at a high temperature of 1000 ° C or higher. Form and the molten salt corrodes the metal. Therefore, it is difficult to use heavy oil for an internal combustion engine or a combustor that extracts energy by combustion because it may damage the equipment.

Taking thermal power generation as an example, in high-efficiency gas turbine power generation equipment, gas fuels such as LNG and light oils such as light oil and kerosene have been conventionally used as fuels. Particularly in gas turbines using oil fuel, vanadium in heavy oil fuel causes high temperature corrosion of the turbine, and therefore, those using light oil fuel occupy most of practical machines. A gas turbine system using heavy oil was also partially put into practical use. At this time, as for vanadium, since a high-melting point oxide causes corrosion of the turbine blade, magnesium is mixed into the fuel as an additive to generate a high-melting point Mg-V composite oxide and solidified in the turbine. Are known (for example, Nishijima, "Heavy oil combustion gas turbine", Journal of the Gas Turbine Society of Japan, 11-43, 1983). However, this method has a problem in that ash adheres to the turbine blades and the continuous operation time (usually 3000 to 6000 hours) must be shortened to clean the blades. For these reasons, the demand for power generation of heavy oil fuels has decreased particularly in Japan, the consumption amount cannot be balanced with light oil, and surplus heavy oil is generated. If this cheap heavy oil is reformed and used as a fuel for a power generation business in high demand, the fuel cost can be kept low and the surplus heavy oil can be effectively used.

A technique aimed at reforming heavy oil into a fuel for a gas turbine is, for example, a method of decomposing and lightening hydrocarbons of heavy oil with supercritical water to produce a flammable gas ( For example, Japanese Patent Laid-Open No. 11-246876) or a method of driving a gas turbine by burning generated gas, and burning a residue left at the time of lightening in a boiler to generate power by a steam turbine (for example, Japanese Patent Laid-Open No. 11-80750). ) Etc. are known. It can be said that these techniques are methods of extracting a part of the hydrocarbon content of the heavy oil and concentrating the substance to be removed, which is a harmful component, in the residue.

Further, a method of reacting heavy oil with supercritical water and an alkali in order to remove the sulfur component in the heavy oil is also known (JP 2000-109850 A, JP 2 A).
000-109851, JP 2001-0500A
No. 10, etc.).

[0006]

The method for reforming heavy oil with supercritical water described in the preceding paragraph can reform a part of the heavy oil into a fuel suitable for a gas turbine. Not all hydrocarbons can be converted to fuel. Further, since harmful substances are concentrated in the residue, it is necessary for the boiler side that burns this to add environmental equipment and take measures against material corrosion.

Further, by adding an alkali,
The vanadium component that causes corrosion cannot be removed by the technique of removing the sulfur content.

An object of the present invention is to reform heavy oil into a fuel having a low material corrosiveness, selectively remove vanadium which is a harmful component in the heavy oil, and carbonize the heavy oil. It is to be able to provide almost all hydrogen for gas turbine combustion. As a result, low-priced heavy oil can be applied to equipment that has conventionally used light oil fuel, such as a highly efficient gas turbine power generation system. In addition, the environmental facility cost can be reduced, and since ash adhesion unlike the magnesium addition method is not involved, long-term continuous operation is possible and the plant operation rate can be improved.

[0009]

The present invention relates to a fuel obtained by reforming heavy oil with supercritical water or subcritical water. In the present invention, supercritical water or subcritical water and heavy oil are mixed, the characteristics of supercritical water as an organic solvent, and the characteristics of a hydrolyzing agent are used to remove the substance to be removed from the heavy oil. , It causes a reaction to be eliminated from the cyclic hydrocarbon molecule in the heavy oil or the porphyrin structure.
At this time, in order to promote the vanadium removal reaction, an oxidizing agent is added.

In the present invention, vanadium oxide decomposed by the above reaction is removed from the reformed fuel by adsorption and reaction. As a method for adsorbing vanadium oxide, there is chemisorption by carbon or the like. In addition, vanadium oxide forms a complex oxide with metals such as calcium and iron,
These metals can be used as scavengers to remove vanadium from heavy oil. By using these scavengers, it becomes possible to trap the substance to be removed and discharge it to the outside of the system in the form of solid. By treating the scavenger taken out of the system, vanadium can be isolated and recycled.

In the present invention, from the heavy oil from which vanadium has been removed by the above-mentioned means, magnesium and calcium are further removed by the same hydrothermal reaction, or the alkali metal is removed by the desalting treatment, and the alkali addition method is used. It is desirable to add a method for removing sulfur to obtain a reformed fuel. According to the present invention, it is possible to provide a fuel suitable for a gas turbine fuel having the strictest fuel specification. That is, the vanadium atom concentration is 0.5 wtppm or less, the lead atom concentration is 1 wtppm or less, the sum of sodium atom concentration and potassium atom concentration is 1 wtppm or less, the calcium atom concentration is 2 wtppm or less, and the magnesium atom concentration is Two
It is possible to provide a fuel having a weight ppm or less and a sulfur atom concentration of 30 weight ppm or less.

Molten salts that cause corrosion in a gas turbine are
Since vanadium is produced by combining with alkali metal or sulfur, gas vane blade corrosion can be largely prevented by vanadium removal alone. However, if a fuel containing the above chemical components is used, it is possible to prevent acid corrosion of the turbine downstream piping due to sulfur oxides and contamination due to metal adhesion to the turbine blades, and it can be safely used by gas turbines and other combustion devices. It can be used as a reformable fuel.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 5, vanadium in heavy oil exists in a porphyrin form centered on vanadium oxide or in a cyclic organic molecular chain (eg, Fish,
RH, Komlenic, JJ, Anal. Chem. 1984, 56 (3), p5
See 10-517). High-temperature, high-pressure water disperses organic molecules in a solvent, and has the action of decomposing the organic molecular chains by hydrolysis. This is called a hydrothermal reaction. However, the action of only high temperature and high pressure water cannot obtain the action of decomposing the vanadium compound in the organic molecule. Vanadium is not decomposed even by the addition of alkali, which is a point different from the sulfur removal reaction of the prior art.

We mix high temperature, high pressure water with heavy oil,
It was confirmed that vanadium was decomposed and removed from the organic molecule by adding an oxidizing agent to the reaction. FIG. 6 shows the relationship between the temperature and the vanadium concentration in oil when heavy oil, water, and hydrogen peroxide water are reacted at high temperature and high pressure. The vanadium concentration decreases with increasing temperature. This reaction, as shown in FIG.
(1) Partial oxidation of organic hydrocarbons, (2) Hydrogen generation by shift reaction of CO and water, (3) Attack of CO on oxygen in organic molecules, (4) Hydrogen molecule, and organic molecule chain cleavage of water It is considered that the action, (5) vanadium oxidation action by the oxidizing agent, etc. proceed simultaneously. By this reaction, vanadium in the organic molecule is decomposed and removed, and vanadium oxide molecule is released.

FIG. 1 shows an embodiment of a reforming apparatus used for heavy oil reforming according to the present invention. A mixer 1 for introducing and mixing high-temperature high-pressure water 2, heavy oil 3, and oxidant 4 is installed at the reformer inlet. The liquid in which water and heavy oil are mixed by the solvent action of supercritical water in the mixer 1 is sent to the reactor 5. As for the mixing of the high-temperature high-pressure water 2, the heavy oil 3 and the oxidant 4, in addition to simple confluence, a method of promoting the mixing by utilizing swirling flow formation or collision by counterflow is also effective. Also, the mixer 1
Is omitted, and high-temperature high-pressure water 2 and heavy oil 3 are directly introduced into the reactor 5.
It is also possible to adopt a configuration in which the oxidant 4 is supplied. In the reactor 5, the reaction shown in FIG. 7 causes the vanadium in the heavy oil to be desorbed from the organic molecules. In order for the desorption reaction to proceed, it is necessary for the system to reach the required temperature and pressure conditions by the outlet of the reactor 5, and as in this example, high-temperature high-pressure water is previously supplied. In addition, it is also possible to adopt a configuration in which water and heavy oil are supplied to the mixer 1 or the reactor 5 and then heated to raise the temperature and pressure. The liquid 7 containing the fuel reformed in the reactor 5 and the desorbed vanadium oxide is taken out through the reformed fuel outlet 6.

FIG. 2 shows another embodiment of the reforming apparatus used for heavy oil reforming according to the present invention. The components up to the mixer 1, the reactor 5, and the reformed fuel discharge port 6 for taking in and mixing the high-temperature high-pressure water 2, the heavy oil 3, and the oxidizer 4 have the same configuration as shown in FIG. Here, the liquid 7 containing vanadium oxide desorbed from the fuel, taken out from the reformed fuel outlet 6.
Are sent through the connecting pipe 8 to a trap 9 installed for separating vanadium oxide. The connecting pipe 8 may be omitted, and the reactor 5 and the trap 9 may be continuous. The trap 9 is filled with the trapping agent 10 for trapping the substance to be removed, and vanadium oxide contained in the flowing liquid is
Capture by adsorption or reaction. As a result, the vanadium concentration in the oil can be reduced to 0.5 weight ppm or less. In addition, the lead atom concentration is 1 wtppm or less, the sum of sodium atom concentration and potassium atom concentration is 1 wtppm or less, the calcium atom concentration is 2 wtppm or less, and the magnesium atom concentration is 2 wtpp.
It is also possible to set the sulfur atom concentration to m or less and 30 ppm by weight or less.

Only vanadium and other metals are captured by the scavenger 10, and almost all of the hydrocarbon component serving as a fuel can be sent to the downstream as the reformed fuel 11. As a method of retaining the capturing agent 10 in the capturing device 9, in addition to a method of retaining the capturing agent 10 as a fixed layer with a fixing material in the form of a plate, the capturing agent is made granular and the particle diameter is equal to or higher than the linear velocity of the liquid. It is also possible to adopt a method of staying in a fluidized bed by adjusting the size so as to have a terminal velocity. Alternatively, a method in which the scavenger is molded into a plate shape or a honeycomb shape and the liquid flows through the gap may be used. As a result of continuous trapping of the substance to be removed, the trapping agent 10 is saturated in trapping ability. However, a system for taking out such a used trapping agent from the trap 9 or a system for supplying a new trapping agent is provided. Other configurations are also possible. Also,
It is also possible to arrange a plurality of traps 9 for one reactor 5 and switch the traps to be used sequentially or to stop a part of the traps at regular intervals, and trap the fuel flow. A configuration and an operating method for exchanging the scavenger therein may be adopted.

FIG. 3 shows another embodiment of the reformer used for reforming heavy oil according to the present invention. The structure from the reactor 5 to the trap 9 is the same as that shown in FIG. The fuel from which vanadium has been removed by the trap 9 is the reformed fuel 11
Is taken out as. A cyclone-type particle collector 12 for collecting particles is installed on the outlet side of the trap 9 in case the trapping agent is mixed in the reformed fuel 11 in the form of particles. A configuration in which a filter is installed as a particle collector can also be adopted. Further, it is of course possible to adopt a configuration in which the particles of the trapping agent 10 collected by the particle collector 12 are returned to the trap 9 for reuse.

FIG. 4 shows an embodiment of a gas turbine power generation system using the reformed fuel reformed from the heavy oil of the present invention as a fuel. 2 and 3, the reformed fuel 11 may be stored or transported and used in a power plant, but in FIG. 4, the produced reformed fuel is burned in an immediate power generation system. It is configured to burn in a vessel. As in FIGS. 2 and 3, in the mixer 1, high-temperature high-pressure water 2, heavy oil 3, and oxidizer 4 are mixed, vanadium is desorbed from the oil in the reactor 5, and captured by the trap 9. Agent 10 captures vanadium oxide. Capture agent 1
In order to prevent the trapped amount of 0 from reaching saturation, a system 12 for extracting the used trapping agent is installed. The used scavenger extracted is sent to the scavenger cleaner 13, and the scavenger is renewed by cleaning and reaction for removing the vanadium compound 14, and is recycled as a recycle scavenger 15 to the scavenger supply system. At this time, in order to replenish the amount of the trapping agent reduced by the reaction, a new input trapping agent 16 is added and returned to the trap 9. In this embodiment, one reactor 5 and one trap 9 are installed, but the reactor and trap are set so that a residence time suitable for reaction and trap can be obtained in the amount of fuel supplied to the gas turbine combustor 20. It is also effective to install multiple units. The produced reformed fuel 11 is combustor 20 with compressed air 19 obtained by compressing air 17 with a compressor 18.
The combustion gas 21 drives the gas turbine 22 and is generated by the connected generator 23. The exhaust gas 24 from the gas turbine transfers heat from the gas to the water 26 in the exhaust gas heat exchanger 25 to generate high-temperature high-pressure water 2,
It is discharged from the chimney 27. The system efficiency can be improved by utilizing the heat of exhaust gas. As in the conventional gas turbine combined cycle power generation system, an exhaust heat recovery boiler may be provided before and after the exhaust gas heat exchanger 25, and a steam turbine may be driven by the generated steam to generate electric power. In addition, a denitration device for removing nitrogen oxides generated during combustion may be installed. In addition, a desulfurization device may be installed to remove sulfur oxides generated by combustion. Since vanadium in heavy oil is removed by the trap 9 from the configuration of this example, there is no risk of high temperature corrosion of the gas turbine, and an additive for producing vanadium and complex oxide such as magnesium. Need not be added. As a result, it is possible to prevent metal oxide ash from adhering to the turbine blades and to perform the same continuous operation as a gas turbine system using light oil fuel, so that it is possible to improve the plant operation rate and realize highly efficient power generation.

[0021]

According to the present invention, heavy oil is reformed with high temperature and high pressure water and an oxidizing agent to remove vanadium and other metals that cause corrosion, so that vanadium concentration and other metal concentrations are extremely high. Low fuel is obtained. Therefore, it is possible to supply the reformed fuel suitable for other devices for extracting energy by combustion, including the gas turbine for power generation. Only harmful metals can be desorbed and captured from heavy oil, and almost all hydrocarbons in heavy oil can be used for combustion. Since low-priced heavy oil can be used without additional environmental equipment or equipment corrosion measures, both equipment costs and running costs can be kept low, and an economically advantageous combustion equipment can be realized.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a heavy oil reforming apparatus used for fuel production of the present invention.

FIG. 2 is a schematic view showing another embodiment of the heavy oil reforming apparatus used for fuel production of the present invention.

FIG. 3 is a schematic view showing another embodiment of the heavy oil reforming apparatus used for fuel production of the present invention.

FIG. 4 is a schematic diagram showing an embodiment of a gas turbine power generation system in which a heavy oil reforming apparatus used for fuel production of the present invention is connected.

FIG. 5 is a diagram showing an example of a vanadium compound form in heavy oil.

FIG. 6 is a view showing an example of a result of a vanadium removal reaction experiment in heavy oil.

FIG. 7 is a prediction diagram of a vanadium removal reaction mechanism in heavy oil.

[Explanation of symbols]

1 ... Mixer, 2 ... High temperature and high pressure water, 3 ... Heavy oil, 4 ... Oxidizing agent, 5 ... Reactor, 6 ... Reformed fuel discharge port, 9 ... Capture device, 1
0 ... Scavenger, 11 ... Reformed fuel, 13 ... Scavenger washer, 1
8 ... Compressor, 20 ... Combustor, 21 ... Combustion gas, 22 ... Gas turbine, 23 ... Generator.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomohiko Miyamoto             2-12-1 Omika-cho, Hitachi-shi, Ibaraki Prefecture             Ceremony Company Hitachi, Ltd. (72) Inventor Jun Morihara             2-12-1 Omika-cho, Hitachi-shi, Ibaraki Prefecture             Ceremony Company Hitachi, Ltd. (72) Inventor Shinichi Inage             2-12-1 Omika-cho, Hitachi-shi, Ibaraki Prefecture             Ceremony Company Hitachi, Ltd. (72) Inventor Hiromi Koizumi             2-12-1 Omika-cho, Hitachi-shi, Ibaraki Prefecture             Ceremony Company Hitachi, Ltd. (72) Inventor Akinori Hayashi             2-12-1 Omika-cho, Hitachi-shi, Ibaraki Prefecture             Ceremony Company Hitachi, Ltd. (72) Inventor Kotaro Inoue             4-6 Kanda Surugadai, Chiyoda-ku, Tokyo             Within Hitachi, Ltd. (72) Inventor Okawa             4-6 Kanda Surugadai, Chiyoda-ku, Tokyo             Within Hitachi, Ltd. F-term (reference) 4H013 AA03 AA04

Claims (4)

[Claims] 1. A heavy oil is reformed with supercritical water or subcritical water in the presence of an oxidizing agent to liberate vanadium molecules contained in the heavy oil, and then a vanadium molecule is solidified with a scavenger. A heavy oil reforming fuel characterized by having a vanadium atom concentration of 0.5 ppm by weight or less. 2. The heavy oil reforming fuel according to claim 1, wherein the oxidizing agent is at least one selected from hydrogen peroxide, oxygen, air, nitric acid and nitrates. 3. Heavy oil is reformed with supercritical water or subcritical water in the presence of an oxidizing agent to release vanadium molecules contained in the heavy oil, and then vanadium is combined with a scavenger. A fuel obtained by separating a reformed oil as a compound having a solid phase from the reformed oil, wherein the heavy oil reformed fuel has a vanadium atom concentration of 0.5 ppm by weight or less. 4. A heavy oil is contacted with supercritical water or subcritical water in the presence of an oxidizing agent to liberate vanadium molecules by a hydrothermal reaction, and the metal contained in the modified oil is converted into a solid. A fuel obtained by separating it from the oil as a compound having a phase, wherein the vanadium atom concentration is 0.5 wtppm or less, the lead atom concentration is 1 wtppm or less, and the sum of the sodium atom concentration and the potassium atom concentration is 1 Weight ppm or less, calcium atomic concentration is 2
A heavy oil reforming fuel characterized by having a weight ppm or less, a magnesium atom concentration of 2 weight ppm or less, and a sulfur atom concentration of 30 weight ppm or less.