JPH0798953B2 - Combustion method of ultra heavy oil-water emulsion fuel - Google Patents

Description

TECHNICAL FIELD The present invention relates to a combustion method of an ultra-heavy oil-water emulsion fuel used as a fuel for a boiler, a fuel for a heating furnace, or the like.

[Conventional technology]

In engine engines such as boilers, gas turbines, and diesel engines, the fuel cost accounts for a large proportion of the operating cost, so even if the fuel supply / demand relationship collapses temporarily and the fuel unit price falls, From a perspective, the conversion of asphalt, petroleum coke, residual oil from petrochemical and petroleum refining processes, and by-product oil into fuels occupy a very important position.

In addition, in the production area of crude oil, for example, super heavy oil found in Venezuela in South America and confirmed to have enormous reserves,
It can be cited as one of the expected fuels for the future.

On the other hand, since the two oil crises, coal has been rapidly reviewed as one of the major pillars of alternative energy to oil, and today nuclear energy is more important than alternative energy.
Like natural gas, it has come to occupy an important position as an energy source.

Furthermore, the development of coal liquefaction and gasification technology has been carried out in Japan and other developed countries around the world, and some results have been obtained.By the time it was put into practical use as fuel for thermal power plants, which is the center of coal utilization. Has not been reached, and has great potential for future development. As fuel for thermal power plants, fine coal powder is dispersed in fuel oil to form COM (Cool Oil Mixtur).
e), CWM (Cool Water) in which fine coal powder is suspended in water
The current situation is to promote effective use of coal fuel by improving existing technologies such as Mixture).

[Problems to be solved by the invention]

However, as is clear from the properties shown in Table 1 below, the above-mentioned super heavy oil has no fluidity at room temperature,
It has many technical problems not only in the form of grease, but also in the transportation from the production area to the consumption area as well as the conversion to fuel.

In other words, in order to make the prime mover fuel, in order to facilitate pipe transportation, tanker transportation, and storage at the power plant, heating with steam or mixing with light oil to improve fluidity. Need to improve. However, steam heating consumes energy, and mixing of light oil also causes an increase in fuel cost, which is not a drastic solution. Ultra heavy oil mixed with light oil may be separated into only light oil by heating and distilling after loading it on a tanker or in an oil storage tank of a power plant. It is clear that this will lead to a rise.

In consideration of such a situation, fine particles of super heavy oil (25 to 30 μm
The most advantageous method is to suspend and disperse m) in water using a surfactant. For example, 70% ultra-heavy oil particles, 29 water
%, A mixture of 1% surfactant can be handled in the same way as liquids, including pipe transportation, loading to tankers, transportation inside oil tanks of power plants, etc. Expected to be done. The water emulsion in which fine particles of this super heavy oil are suspended is called
Although it is in the form of an emulsion of O / W type, it can solve the above-mentioned problems in the transportation process, but it is difficult to burn it with water containing about 30%, and the combustion energy is consumed for the evaporation of water. Therefore, the water content in the emulsion should be as low as possible. Therefore, the removal of the water content can be performed by a conventional method such as an operation by heating or a reduced pressure, or after adding an emulsion breaker, separating the super heavy oil particles and water by a centrifuge.

However, even if this method is used, O /
There is no change in the W type emulsion, and when it is used as it is as a fuel for the boiler, the combustibility is poor, and unburned carbon content increases with this, and there is a problem in smoke pollution,
Currently no good plan has been developed.

In addition, as shown in Table 1 above, a large amount of vanadium, sulfur, and sodium are contained in the ultra-heavy oil, and after combustion, these become all the components of the fuel ash and cause accelerated oxidative corrosion of the boiler heat transfer tube. At the same time, sulfur is present in exhaust gas in the form of sulfuric acid, and the problem of inducing corrosion of air preheaters, dust collectors, chimneys (called sulfuric acid dew point corrosion) is not solved.

On the other hand, with the above-mentioned COM, the amount of heavy oil used can be reduced, but there is a problem in its storage and transportation. Under current usage conditions, it is better to use pulverized coal and heavy oil separately. Since the technology and equipment can be used as they are, it is considered unlikely to grow significantly in the future.

However, in the high temperature part and the furnace evaporator tubes of the boiler is burned in pulverized coal alone, alkali contained in coal, iron, alkaline-iron-sulfate compounds made from sulfur components [M ₃ · Fe
(SO ₄ ) ₃ ] and alkaline sulfates (M ₂ S ₂ O ₇ etc.) (however, M is K or Na) causes sulfide corrosion damage.

〔Purpose〕

The present invention intends to use the above-mentioned ultra-heavy oil and pulverized coal as a fuel, and provides a method for burning an ultra-heavy oil-water emulsion fuel which solves the above problems associated with the fuel. With the goal.

[Means for solving problems]

And the present invention, as a means for achieving the above object, O /
W type emulsion, mixed emulsion of O / W type and W / O type or super heavy oil made into W / O type emulsion-water emulsion fuel, combustion accelerator, anticorrosive additive, pulverized coal alone or in various combinations. It is in the point of adding and burning.

That is, the present invention (1) prepares an O / W type emulsion, a mixed emulsion of O / W type and W / O type or a W / O type emulsion from fine particles of ultra-heavy oil and water that are grease-like at least at room temperature. , A combustion promoter composed of Fe or Mn compound and Ca or Mg
Combustion method of ultra-heavy oil-water emulsion characterized by adding anticorrosion additive composed of compound and burning (2) O / W emulsion from ultra-heavy oil fine particles and water showing grease at least at room temperature , A mixed emulsion of O / W type and W / O type or a W / O type emulsion is added, and pulverized coal is added to the emulsion, and the mixture is burned. A method for burning an ultra heavy oil-water emulsion fuel.

(3) O / W type emulsion, mixed emulsion of O / W type and W / O type or W / O type emulsion is prepared from fine particles of ultra-heavy oil and water showing grease at least at room temperature, and pulverized coal is added to this. And a combustion accelerator comprising a compound of Fe, Ba or Mn, and burning the fuel, which relates to a combustion method for an ultra heavy oil-water emulsion fuel.

The present invention is described in detail below.
By using a mixed emulsion of W type and W / O type or a W / O type emulsion, it is possible to improve combustibility and suppress generation of thermal NOx. That is, O
Since the / W type emulsion has poor flammability, it can be mixed with the W / O type or changed to the W / O type emulsion and then burned to improve the flammability of the water mixed in the fuel. In addition to being useful, it also suppresses the generation of thermal NOx.

Further, in the present invention, in the case of the O / W type emulsion, in order to improve the combustibility and the like, hydrophilic Fe ₂ O ₃ , FeOOH, FeCO ₃ , Fe
Combustion promoters such as ₃ O ₄ , iron acetate, BaCO ₃ , MnO ₂ and Mg (O
H) ₂ , burns after injecting anticorrosion additives such as MgO.

On the other hand, in the case of a mixed emulsion state of the above O / W type and W / O type, or in the case of a W / O type emulsion state, an oil-soluble iron compound such as iron octylate, iron naphthenate, stearic acid. Mg at the bonding position of iron, iron methacrylate, and iron
(For example, magnesium naphthenate), Ca (calcium naphthenate), or the surface of the hydrophilic compound coated with a lipophilic surfactant is added and burned to form an O / W type. The effect described above by mixing with the W / O type or the W / O type and the corrosion damage prevention of the boiler caused by the vanadium compound and the S compound contained in the heavy oil are aimed at.

Furthermore, in the present invention, O / W type emulsion and O / W type
W / O type mixed emulsion, by mixing pulverized coal to W / O type emulsion, and also with the pulverized coal hydrophilic compound or oil-soluble compound or a lipophilic surfactant on the surface of a hydrophilic compound Sulfurized corrosion that occurs in the combustion of pulverized coal, etc.
The V compound generated when these emulsions are burned suppresses the corrosion action of the V compound that is generated when only these emulsions are burned. The direct contact of the V compound is blocked, or the V compound reacts with the coal ash component to be relaxed.

Further, the ash content of coal ash has a high electric resistance on fire and the collection efficiency of the electrostatic precipitator is low, but the presence of the ash content of the emulsion reduces the resistance value and improves the collection efficiency.

[Action]

In the present invention, in order to prepare a mixed emulsion of super heavy oil O / W type and W / O type or a W / O type emulsion, part or all of the O / W type can be changed to W / O type. preferable. The reason for this conversion action and flammability, and the action of the combustion accelerator, anticorrosion additive, and pulverized coal added in the present invention will be described below.

(1) Reasons for conversion from O / W type to W / O type emulsion and improvement of flammability: Fig. 1 is a schematic diagram of O / W type emulsion, and Fig. 2 is W / O type. It is the figure which showed the type emulsion typically. As shown in Fig. 1, the O / W emulsion in which the particles of ultra-heavy oil coexist with water is
In contrast to the water W existing around, the W / O type emulsion has a state in which the particles (water droplets) of the water W are surrounded by super heavy oil, as shown in FIG. It is in a state of being surrounded by oil droplets O ′ containing fine particles O of ultra-heavy oil.

The conversion from O / W type to W / O type is carried out by adding an lipophilic anion activator to the O / W type emulsion, for example, sodium alkylsulfonate, and then stirring it well, by the action of the activator. As the surface tension of water decreases, the lipophilic group of the activator attaches to the surface of the oil particles, changing from O / W type to W / O type. In this case, heating to 80 ° C. or higher can weaken the action of the surfactant added to the O / W emulsion, so the O / W type is converted to the W / O type,
There is also a state where both are mixed. Furthermore, when heavy oil is added to this operation, it becomes easy to change to a W / O emulsion.

Next, the flammability of the O / W type and W / O type emulsions will be described.

As is clear from the schematic diagram of FIG. 1, when the O / W type emulsion is sprayed into the boiler furnace, first, the water W in the outer peripheral portion evaporates, and then the oil particles O start to burn. . At this time, the latent heat associated with the evaporation of water is removed, so that the temperature rise of the oil particles is delayed, and the combustion is not fully completed, but is included in the exhaust gas and goes out of the boiler.

On the other hand, in the W / O type, first, the oil particles O are heated, and when the water droplets W contained therein reach 100 ° C or more, they are vaporized all at once, and this expansion force causes a wide range. In addition, the oil particles become finer particles and scatter, and the combustibility is improved. Because of this, O / W type and W / O type are mixed even if they are mixed.
Combustibility is improved compared to W type.

(2) Action of combustion promoter: When a combustion promoter (for example, Fe, Ba, Mn compound) is added to the O / W emulsion, after the surrounding water evaporates, these promoters are The oil particles adhere to the surface even if they are coated or not. These deposits act as an oxidation catalyst, and even if the temperature of the oil particles does not rise, the catalytic action causes the oil particles to start combustion from a low temperature. Therefore, the combustibility in the boiler furnace is promoted and the unburned carbon content is reduced as compared with the case of the O / W type in which the accelerator is not added.

Further, in the W / O type emulsion, since the oil-soluble combustion accelerator is added, the accelerator always coats the surface of the oil particles, and the flammability is further improved compared to the O / W type ( The temperature rises quickly, and the oil particles become even finer due to the rupture of water droplets, and physical factors such as better contact with air are also taken into account.

(3) Action of anticorrosion additive: In the case of the O / W type emulsion, the anticorrosion additive composed of Ca or Mg compound together with the combustion accelerator of the item (2) is used in the form of water slurry, and O / W type and W / When O type is mixed, it is added up to water slurry and oil slurry, and in the case of W / O type emulsion, oil slurry or the surface of the additive is added in a state of being coated with a lipophilic activator. As a result, the corrosive components generated by the combustion of the oil particles, such as V ₂ O ₅ and the Mg compound, react in a short period of time, and have the effect of increasing the melting point of V ₂ O ₅ having a low melting point. That is, in the V ₂ O ₅ alone the melting point of 660~690 ℃ V ₂ O ₅
＋ 2MgO → V ₂ O ₅・ 2MgO (melting point 835 ℃) V ₂ O ₅ ＋ 3MgO → V ₂ O ₅・ 3MgO (melting point 1191 ℃) It should be noted that Ca, which has a combustion promoting effect, also has V ₂ O ₂
· 2CaO (mp _{778 ℃), V 2 O 2} · 3CaO ( mp 1016 ° C.) is produced. These V-Mg compound and V-Ca compound adhere to the boiler heat transfer surface in a solid state. For this reason, the corrosiveness is significantly reduced, and the soot blower facilitates separation from the heat transfer surface, improving the heat absorption rate.

Also, MgO and MgSO ₄ (react with SO ₃ in the combustion gas in the low temperature part of the boiler, or where sulfuric acid in the gas is condensed,
Reacts with this to form MgSO ₄ ) and the surface temperature of the heat transfer tube is 400
When it adheres at a temperature of ~ 600 ° C, it covers the surface of the combustion ash and prevents the contact of V ₂ O ₅ and Fe ₂ O ₃ contained in the fuel with SO ₂ in the gas and conversion to SO ₃ . This has the effect of suppressing and reducing the amount of sulfuric acid that condenses, thereby reducing the corrosive effect.

However, when only this Ca or Mg compound is added, the following trouble may occur because this compound is white. That is, when the boiler combustion chamber adheres to the surface of the evaporation tube, it becomes as if it were surrounded by the wall of chalk, and the flame temperature burning in the center of the combustion tube is not radiant heat due to the whitened evaporation tube, and the temperature is high. Because the state continues
This will promote the generation of so-called thermal NOx.

In the present invention, since the colored iron compound and the Mn compound are added as the combustion accelerator as described above, since the whitened evaporation tube is colored in iron rust color (brown), the radiation absorption rate is increased, The combustion flame and the temperature of the combustion gas in the vicinity of the combustion flame return to their normal values correspondingly, so that the generation of thermal NOx can be suppressed.

For the above reasons, by only mixing colored Fe, Mn compounds in Ca or Mg compounds in an amount of about 2 to 5%, the corrosion-preventing action of Ca or Mg compounds can be utilized as it is, and white compounds of this kind can be used. It is possible to make up for the drawback of thermal NOx generation caused by the above.

(4) Emulsion (O / W type, mixed O / W type and W / O type, W
Corrosion component and its action in pulverized coal and each of the / O type emulsions (the same applies below) The corrosion components in emulsions are three elements, V, Na, and S, which react with each other in the combustion gas. V ₂ O ₅ ,, Na ₂ O ・ n
V ₂ O ₅ , 5Na ₂ O ・ V ₂ O ₄・ 11V ₂ O ₅ , Na ₂ SO ₄ , SO ₃ etc. are generated,
These compounds directly corrode the boiler tube and air preheater elements in this state.

On the other hand, the corrosive components contained in coal are K, Na, and S.
Mainly composed of elements, it forms compounds such as K ₂ SO ₄ , Na ₂ SO ₄ , and SO ₃ in the combustion gas, and adheres to the boiler tube surface in the state of being mixed with other ash main components (see Table 7). To do. K ₂ SO ₄ and Na ₂ SO ₄ adhering to the boiler tube react with iron oxides in other ash components in the presence of SO ₃ , and the melting point is low and strong corrosive alkali / iron / This produces sulfate compounds. This sulfate compound was hardly found in the upper layer of the fuel ash on the boiler tube, and was contained in large quantities at the boundary between the fuel ash and the boiler tube. It is thought that various reactions occur and form a sulfate compound with strong corrosiveness.

3Na ₂ SO ₄ + Fe ₂ O ₃ + SO ₃ → 2Na ₃ Fe (SO ₄ ) ₂ (1) 3K ₂ SO ₄ + Fe ₂ O ₃ + SO ₃ → 2K ₃ Fe (SO ₄ ) ₂ (2) Na ₂ SO ₄ melting point Is 884 ℃, that of K ₂ SO ₄ is as high as 1069 ℃,
Na ₃ Fe (SO ₄ ) ₃ is as low as 624 ° C and K ₃ Fe (SO ₄ ) ₃ is as low as 618 ° C, and when both coexist, it forms a eutectic with a melting point of 550 ° C and melts. Strong corrosion occurs even in low heat transfer tubes. Moreover, the sulfuric acid compound having strong corrosiveness exhibits corrosiveness in a state where oxygen in the atmosphere is small, as can be seen from the fact that the sulfuric acid compound gathers at the boundary between the fuel ash and the tube as described above.

When V compounds of Emarujiyon fuel is present in the form of V ₂ O _5, which has the property of releasing oxygen as _{V 2 O 5 V 2 O 4} + 1 / 2O 2. Therefore, the existence of V ₂ O ₅ suggests that Na
_{3 Fe (SO 4) 3,} K 3 Fe (SO 4) whereas for directly preventing the corrosion of _3, the (1) (2) to Yotsute _{N 3 Fe (SO 4) 3} , K 3 F
It is considered to have an action of preventing the formation of e (SO ₄ ) ₃ .

On the other hand, from the viewpoint of V ₂ O ₅ which is a corrosive component of emulsified fuel ash, a large amount of ash (10 to 20% of coal) is present in the coal ash, and the main components are SiO ₂ , CaO, Al ₂ Since it is a high melting point compound such as O _3, its corrosive action is physically and chemically weakened (see Tables 1 and 7).

(5) Improvement of flammability by addition of pulverized coal and combustion accelerator and its action When pulverized coal and compounds such as Fe, Ba, Mn are attached to emulsion fuel, oxides of these elements are generated in combustion environment. Since it acts as an oxidant, it promotes combustion and reduces unburned carbon content in the combustion exhaust gas.

Compounds such as Fe, Ba and Mn are more effective when they exhibit lipophilicity. Since the surfaces of oil and pulverized coal in emulsion fuel are all hydrophobic, if Fe, Ba, Mn compounds of this kind are made lipophilic, they will be adsorbed on oil particles and the surface of pulverized coal, further promoting their combustion. Because it will be. In the mixture of O / W type and W / O type, and in W / O type fuel, it is ideal to add it as an organic compound (of Fe, Ba, Mn). When fine particles of oxides such as Fe ₂ O ₃ , BaO, and MnO ₂ are added, all of these oxides are hydrophilic, and are therefore unlikely to adhere to oil particles or the surface of pulverized coal. Therefore, it is better to coat the surface of such oxide particles with a lipophilic surfactant in advance.

(6) Improvement of dust collection efficiency There is a close relationship between the electrical resistance of dust in combustion gas and dust collection efficiency. Since the ash of pulverized coal as shown in Table 7 has a very high electric resistance (for example, 10 ^{12 to 13} Ωcm), the efficiency of electrostatic collection is not good. However, when Fe and Mn compounds are added to the pulverized coal, sulfuric acid is adsorbed on the surface of the fine powder of these compounds (SO _{2 in} the gas is reduced by the oxidation of Fe ₂ O ₃ and MnO ₂ ).
₂ is oxidized to SO ₃ and reacts with the water in the gas to react with H ₂ O + SO ₃ →
H ₂ SO ₄ ), reduce the electric resistance of dust,
If you improve the condition so that it easily attaches to the electrostatic precipitator (10
^{10 to 11} Ωcm).

If you burn the emulsion fuel and pulverized coal together,
Depending on the mixing ratio, the electric resistance of dust is 10
Since it is ^8-10 Ωcm, the dust collection efficiency is good. It should be noted that when the emulsion fuel without addition of pulverized coal is burned, since it is 10 ^{6 to 8} Ωcm, it is in a state where dust is relatively easily collected.

Next, an example of a combustion apparatus to which the combustion method of the present invention is applied will be described with reference to FIG.

FIG. 3 is a cross-sectional view of a boiler to which the combustion method of the present invention is applied. The fuel spray-injected into the combustion chamber 1 is burned here and becomes high-temperature combustion gas (1000 ° C. to 1200 ° C.). Arrow 2
Flowing in the direction of. A high temperature superheater 3, 3 ′ and a high temperature reheater 4 are installed in the passage through which the high temperature combustion gas flows, and flow to the rear flue while exchanging heat between them, and again, the horizontal type low temperature superheater The heat is exchanged with the reactor 5, the low temperature reheater 6, the economizer 7, etc., and passes through the denitration catalyst layer 8 to reach the air preheater 9. The combustion gas temperature at the inlet of the air preheater 9 is 340 to 370 ° C. In the air preheater 9, the combustion air is heated, the dust and dirt in the gas are removed by the electric dust collector 10, and the dust is discharged from the chimney (not shown) to the outside of the system. A so-called flue gas desulfurization device for removing SOx in the gas is provided between the electric dust collector 10 and the chimney, but it is omitted here. In addition, 11 indicates the flow of combustion air, 12 is an ammonia injection pipe injected to smoothly perform the action of the denitration catalyst, 13 is an evaporation pipe forming a combustion chamber, and 14 is combustion. It shows a flame.

〔Example〕

Example 1 (Example of use as O / W emulsion) 70% super heavy oil (super heavy oil in Table 1), 29% water, and nonionic surfactant [nonylphenyl (EO) 10
-12, where E · O represents ethylene oxide. ] 1
% Is used as the basic fuel of the O / W type emulsion.
An example in which a combustion accelerator and / or an anticorrosive additive was added to the composition for combustion was applied to combustion in a boiler based on FIG. 3, and the following (1) and (2) were tested. The results are described in (3).

(1) Test fuel conditions: (A); O / W type emulsion fuel was burned as it was.
(Comparative Example) (B); Barium acetate was added to the fuel of (A) so as to be 1000 ppm.

(C); Iron sulfate was added to the fuel of (A) so as to be 1000 ppm.

(D); Mg (OH) ₂ was added to the fuel of (A) at a weight ratio of 1: 1 (Mg / V) to the amount of V in the fuel.

(E); (B) and (C) were added simultaneously.

(F); (C) and (D) were added simultaneously.

(2) Test item: Each of the above fuels was burned for 1000 hours, and the following items were measured.

Measure NOx and SO ₃ emissions at the ammonia injection position (judgment of environmental pollution and sulfuric acid dew point corrosion) Measure dust emissions at the air preheater outlet, that is, at the inlet and outlet of the electrostatic precipitator (combustibility and electrostatic precipitator) The fuel ash adhering to the superheater pipe is collected and its melting point is measured (to determine the high temperature corrosiveness of the combustion lung. The lower the melting point of the fuel ash, the stronger the corrosiveness, and the higher the temperature, the weaker the corrosiveness. Performance of denitration catalyst (NO in gas at inlet and outlet of catalyst layer)
The amount of x was measured and the change in performance with the passage of operating time was investigated.) (3) Test results: The test results are summarized in Table 2 below.

In Table 2 above, (A) each measured value when the O / W type emulsion fuel is burned, and the measured value of (A) is 100,
(B) to (F) The values at the time of fuel combustion are shown by the ratio. That is, regarding the amount of NOx generated, the value at the time of combustion of the O / W type emulsion of (A) is set to 100, and the values of (B) to (F) are displayed as a ratio to 100, and the denitration efficiency was calculated as follows. .

Denitration efficiency = β / α × 100 α: NOx amount in the gas at the denitration catalyst inlet, which is the NOx generation amount β: NOx amount in the gas at the denitration catalyst outlet However, the melting point of the combustion ash is the measured value itself.

As is clear from this result, (A) When burning alone, there are problems that the amount of dust is large, the efficiency of the electrostatic precipitator is low, and the melting point of combustion ash is low.

On the other hand, in the case of adding (B) Ba, the amount of soot and dust is reduced and the effect of improving combustibility can be recognized, but NOx
An increase in the amount generated is recognized, and the melting point of the combustion ash is not much different from that of (A). The addition of Mg (OH) ₂ in (D) also increased the amount of NOx produced, but increased the melting point of the combustion ash and
It was found that the amount of SO ₃ generated was reduced.

The cause of the NOx generation amount is considered as follows. Since the Ba and Mg compounds are both white compounds, if they adhere to the surface of the evaporation tube, they will become a white wall, and combustion will take place in it, and the radiation absorption rate of the evaporation tube will decrease, resulting in a combustion flame. As a result of high temperature for a long time, thermal NOx
It seems that this has promoted the occurrence of. On the other hand, the decrease in SO ₃ is caused by the Ba and Mg compounds covering the surface of the fuel ash and the V ₂ O ₅ , Fe in the fuel ash.
_It interferes with the contact between catalyst components such as ₂ O ₃ and SO ₂ in the gas, and
It is considered that the oxidation of ₂ → SO ₃ was suppressed.

In contrast to the ones using the white additive as above,
It has been found that the iron addition (C) reduces the amount of dust generation and improves the efficiency of the electrostatic precipitator. This is because the injected iron becomes Fe ₂ O _{3 in the} combustion gas,
It is considered that the combustion efficiency of the unburned carbon was promoted and the electric resistance of the unburned carbon content was improved by mixing with these, and the collection efficiency of the electrostatic precipitator was improved. It is also recognized that it is effective in maintaining the performance of the denitration catalyst. However, the effect of increasing the melting point of combustion ash is not so great.

As in (E) and (F), the addition of iron to the white-based additive shows the advantages of the white-based additive and the performance that compensates for the drawbacks. This is because the white compound is colored by the addition of iron,
This is because while the heat absorption rate of the evaporation tube is improved, the melting point increasing effect of Mg on fuel ash and the SO ₃ suppressing effect are directly exhibited.

Example 2 (Change from O / W type emulsion to W / O type emulsion) The following treatment was performed as a method of changing from the O / W type emulsion shown in Example 1 to a W / O type emulsion.

(1) An O / W emulsion was heated (80 to 120 ° C.), 2000 ppm of an oil-soluble anionic surfactant was added thereto, and the mixture was stirred well. As a result, the O / W type and W / O type emulsion coexist, if not the perfect type W / O type, that is,
It was a mixed emulsion fuel of O / W type and W / O type. O / W
A nonionic surfactant [nonyl phenyl (EO) _{9 to} 17 (where _EO is an abbreviation of ethylene oxide) was added to the emulsion emulsion, but when heated to 80 ° C or higher, O The action of the nonionic surfactant forming the / W type is weakened, and the action of the anionic surfactant causes O / W.
It is considered that a part of the mold changed to W / O type. Although sodium alkylbenzene sulphonate was used as the anionic surfactant here, the same effect was exhibited even when the same magnesium sulphonate was used. Also, when these oil-soluble anionic surfactants were added at 20000 ppm, most of them changed to W / O type. The mixture ratio of O / W type and W / O type can be adjusted by the heating temperature of the emulsion fuel and its time and the addition amount of the anionic surfactant. It can be decided.

(2) After adding C heavy oil 0.2 to O / W emulsion 1 and heating (80 to 120 ° C.), 2000 ppm of the same oil-soluble anionic surfactant as in (1) was added and stirred. This method was also able to convert from O / W type to W / O type. However, the rate of change was extremely higher than that of the method (1), and most of the anionic surfactants could be converted to the W / O type by adding 10,000 ppm of the anionic surfactant.

Hereinafter, a combustion test was performed using an emulsion fuel in which the O / W type and the W / O type were mixed at a ratio of about 50:50 and a W / O type emulsion fuel.

(1) Test boiler: The same boiler as in Example 1 was used.

(2) Tested fuel conditions; the same as in Example 1. However, as the iron compound, oil-soluble iron octylate was used.

(3) Test item: same as in Example 1.

(4) Test results; The following Table 3 summarizes the test results when using the emulsion fuel (A ') in which the O / W type and the W / O type are mixed.

In Table 3, the data when the (A) O / W type emulsion fuel (without addition) used in Example 1 was used as 100, and the measured values of this example are shown as ratios thereof.
However, only the melting point of the fuel ash was recorded as it was.

As is clear from the results shown in Table 3, the flammability was improved by using the mixed emulsion of O / W type and W / O type. However, the drawbacks such as the low melting point of fuel ash and the large amount of SO ₃ generated are directly observed.

As is clear from Table 3, (C) of Example 1,
(E), (F) The same additive as the fuel was added to the mixed emulsion of O / W type and W / O type (C), (E '), (F')
The fuel showed good results in all test items, and it was found that the present invention is also effective when a mixed emulsion fuel of O / W type and W / O type is used.

Table 4 shows the results of tests conducted on fuel (A ″) that was added with heavy oil and was mostly W / O type emulsion (A ″). Results similar to those of Table 3 were obtained in this test as well. Therefore, the effect of the present invention was confirmed.

Example 3 (Effect Confirmation Test of Various Additives) In Examples 1 and 2, the effects of compounds of three elements Ba, Fe, and Mg were investigated, but in this Example, the effects of other compounds were investigated.

(1) Samples tested: (A); O / W type emulsion [fuel (A) of Example 1] (B); O / W type and W / O type mixed emulsion [fuel of Example 2 (A ' )] (C); W / O type emulsion (fuel (A ″) of Example 2) (2) Type of additive: (a); Fe ₂ O ₃ for O / W type emulsion (A) , FeOO
H, MnO ₂ (b); O / W type and W / O type mixed emulsion (A ′), for (a) additive and iron naphthenate, iron stearate (c); W / O type Fe ₂ O ₃ F for emulsion (A ″)
eOOH particles whose surface is coated with a lipophilic surfactant (sodium alkylbenzene sulphonate) and iron naphthenate, iron stearate For each fuel of (a), (b) and (c) On the other hand, the Mg (O) ratio should be adjusted so that Mg / V = 1 or Ca / V = 1 by weight ratio with respect to the V compound contained in the super heavy oil in the fuel.
H) ₂ , calcium stearate was added.

(3) Test boiler: Same as in Example 1 (4) Survey item: Dust generation amount (5) Survey results: The survey results are summarized in Table 5 below.

(Remarks) Reduced by 10% or more due to the amount of soot and dust generated when no additives are added Those with a reduction of 20% or more ○, those with a reduction of 30% or more ◎
Displayed as.

As is clear from Table 5 above, as the combustion promoter, Fe ₂ O ₃ will be generated in the high temperature combustion gas regardless of the compound form in the fuel and regardless of the type of emulsion. You can see that it is effective if it is. Also, Mn
O ₂ has the same effect as Fl ₂ O ₃ . It is considered that this is because it has a strong oxidative action for promoting combustion. Calcium stearate used as a corrosion inhibitor had the effect of increasing the melting point of fuel ash and was also found to have a corrosion inhibiting effect on fuel ash.
It was very hard and difficult to peel off from the heat transfer tube as compared with the case of injection.

Example 4 (Pulverized coal combustion ash content and emulsion ((O / W
Type, mixed emulsion of O / W type and W / O type, W / O type)) Corrosion test of combustion ash) In this example, the ash content after pulverized coal combustion, that is, the corrosion contained in coal ash content M ₃ Fe (SO ₄ ) ₃ which is a component, and the corrosive component V ₂ O ₅ contained in the ash after combustion
, And the corrosion test was carried out in the state of being used alone or in a mixed state.

(1) Test corrosive agent: (a) Corrosion component in coal ash: 1.5 mol Na ₂ SO ₄ +1.5 mol K ₂ S
O ₄ +1 mole Fe ₂ O ₃ a mixture of (react with each other upon standing the mixture in the combustion gas, strong corrosive M ₃ Fe
(SO ₄ ) Make ₃ However, M shows Na or K. ) (B) Corrosion component in heavy oil: V ₂ O ₅ (2) Test material: STBA24 (21) used as boiler superheater tube material
/ 4Cr-1Mo steel) and SUS321HTB (containing 18Cr-8Ni-Ti)
Processed into test pieces with a width of 15 mm, a length of 30 mm, and a thickness of 3 mm,
The one that was well polished with emery paper (No. 600) was used.

(3) Corrosion test conditions and method: A test piece and a corrosive agent were put in a magnetic boat-shaped container, and a synthetic gas (1% SO ₂ + 5% O ₂₎ simulating a combustion gas in a tubular electric furnace.
₂ ＋ 12% CO ₂ + remaining N ₂ ) at 200 ℃ per minute at 700 ℃
A corrosion test of × 100 hours was carried out.

The amount of the corrosive agent was fixed so that it was 30 mg / cm ² per surface area of the test piece, but in the case of the mixed corrosive agent, it was M ₃ Fe (SO ₄ ) ₃
A / V ₂ O ₃ ratio of 3/1 (weight ratio) was used (M: Na or K).

(4) Test result: The corrosion amount of the test piece is the weight before and after the test after the corrosion product adhering to the surface after the test is immersed in 10% hydrochloric acid containing an acid corrosion inhibitor (inhibitor) to be removed. The corrosion weight loss was calculated from the difference.

Table 6 shows the results.

As is clear from Table 6, the corrosive amount of the sole corrosive component in the coal ash was the largest, followed by V ₂ O ₅ , but when both were present in a mixed state, the corrosive amount was drastically reduced. . Although the cause of this is not clear, while the corrosive effect of M ₃ Fe (SO ₄ ) ₃ occurs strongly in an oxygen-deficient environment, V ₂ O ₅
It is considered that the corrosive action was slowed because oxygen was supplied by the presence of.

On the other hand, V ₂ O ₅ becomes V ₂ O _{4 as} a result of oxygen supply to M ₃ Fe (SO ₄ ) ₃ .
Or, it seems to have changed to a lower oxide such as V ₂ O ₃ and lost the corrosiveness. Incidentally, the melting points of V ₂ O ₄ and V ₂ O ₃ are both 190
Above 0 ° C, it exists as a solid at the test temperature of 700 ° C and shows no high temperature corrosive effect.

Moreover, since the above-mentioned characteristics of corrosion are recognized in both STBA24 and SUS321HTB, it seems safe to consider it as the corrosion characteristics of all boiler heat transfer tubes.

Example 5 (Test for confirming effect of addition of pulverized coal) (1) Outline of test combustion equipment: Fig. 4 shows an outline of the test combustion equipment used in this example.

In FIG. 4, 101 is a blower for supplying combustion air, which can be heated to 100 to 250 ° C. by the primary heater 102 and 250 to 500 ° C. when passing through the secondary heater 103.
The air that has exited is passed through the low temperature pipe 104 and is used for combustion of the emulsion fuel, and the air that has exited the secondary heater 103 is supplied by the hot air pipe 105 for the combustion of pulverized coal. Reference numeral 106 denotes an oxygen cylinder, which is fed to the air pipe 107 branched from the blower 101 in order to accelerate the ignition of the fuel, and when the combustion reaches a stable state, the cylinder 106 is closed.

Numeral 108 is an emulsion fuel tank, and a pump 109 is used to change the burner 110 for emulsion to the burner 11 in the combustion furnace 111.
While injecting into the vicinity of 2, part of it passes through the pipe 113,
It can be fed into the fuel mixer 114.

On the other hand, the coal powder in the fine powder storage tank 115 is sent from the pipe 117 to the fuel mixer 114 by the screw feeder 116 and is burned with the heated air supplied from the pipe 105 through the pipe 117 ′. It can also be injected into the furnace 111 and burned.

A plurality of boiler tubes 118, 118 'for testing are attached to the central portion of the combustion furnace 111, and the outer surface temperature of the tubes 118, 118' can be adjusted by cooling air 119.

The combustion gas passes through the test boiler, exits from the combustion furnace outlet 120, enters the cyclone 121 and is removed, and the collected dust is taken out from the lower part of the cyclone 121, and the combustion gas that comes out from the upper part is Further, it is cleaned by the electrostatic precipitator 122 and discharged from the chimney 124 to the outside by the suction blower 123.

Further, as the combustion test is continued, the combustion ash staying in the combustion furnace 111 is discharged to the outside from the ash extraction port 125 in the lower portion.

The fuel mixer 114 is used when mixing a small amount of pulverized coal with emulsion fuel and when injecting various additives into it.

The combustion amount is 2t / h in terms of emulsion.

As is clear from FIG. 4, in this test combustion furnace, of course, each of the emulsion and the pulverized coal is burned independently.
It is also possible to burn both in a mixed state.

The amount of dust, NOx, SO ₃ etc. in the combustion gas is measured by the ◎ mark at the combustion furnace outlet, or the efficiency of the electrostatic precipitator is determined by the amount of dust contained in the gas before and after the electrostatic precipitator. A comparison of properties and deposit accumulation was carried out with 17,17 'boiler tubes.

(2) Types of test fuels (A) Emulsion fuel: O / W type emulsion: 70% super heavy oil (fine particles of 30 to 5 μm) + water 19% + nonionic interface having properties as shown in Table 1. Activator (nonyl phenyl (EO) x, x
= 10 to 17 or less were used in a mixed state) 1% (all in weight%) Mixed emulsion of O / W type and W / O type: Using the above O / W type emulsion, by the method of Example 2 O / W type / W / O type ratio 50/50
W / O type emulsion: Using the above O / W type emulsion,
Mostly W / O type by the method (2) of Example 2 (B) Pulverized coal fuel: 80% or more of coal having the properties shown in Table 7 passes through a 200-mesh sieve. Adjusted to.

(3) Fuel combustion conditions: (A) O / W type, a mixture of O / W type and W / O type, and pulverized coal is added to each of the W / O type fuels in an amount of 10% (% by weight) for combustion. (B) Only pulverized coal is burned.

(C) The emulsion fuel and the pulverized coal are burned by separate (exclusive) burners 110 and 112 in FIG.

(4) Types of fuel additives: (A) Additives to O / W type fuels: ferrous sulfate, barium acetate, Fe ₂ O ₃ powder, MnO ₂ powder (B) O / W type and W / O Type mixing and additive to W / O type fuel: Additive of (A), iron octylate, iron naphthenate (C) Additive to pulverized coal fuel: Fe ₂ O ₃ powder, iron octylate The Fe ₂ O ₃ and MnO ₂ powders were fine particles of 0.1 to 1 μm, and the surface thereof was coated with a lipophilic nonyl phenyl (E · O) xx = 7 or less. As a result, when added to O / W type fuel, it tends to adhere to the surface of ultra-heavy oil particles, and even when added to other fuels, it always adheres to the surface of oil or coal, promoting its combustion. There is.

Further, the injection amount of the above additives is 2000 ppm (weight) for BaO and Fe ₂ O ₃ , respectively.

(5) Test results (A) When pulverized coal was mixed and burned in O / W type emulsion fuel Table 8 summarizes the test results.

As is clear from Table 8, when the additive is injected and burned, the dust generation amount, dust collection efficiency, NOx and SO ₃ generation amount are all better than those of the additive-free combustion. Is shown. In addition, it was confirmed that the amount of deposits of fuel ash deposited on the test tube and the amount of corrosion thereof were also reduced.

(B) O / W type + W / O type mixed emulsion fuel mixed with pulverized coal and burned Table 9 summarizes the results of this test.

As is clear from Table 9, the effect of the present invention was recognized as in the case of the above (A).

(C) When pulverized coal was mixed and burned in W / O type emulsion fuel Table 10 summarizes the results of this test.

As is clear from Table 10, the effects of the present invention were recognized as in the results (A) and (B).

(D) When the emulsion fuel and the pulverized coal are burned separately Both fuels are burned by the burners 110 and 112 in FIG. 4, and Fe ₂
An additive of O ₃ powder and iron octylate was added to the emulsion fuel / pulverized coal in a ratio of 6/4 (weight ratio) and tested.

Table 11 shows the results.

As is clear from Table 11, even if the emulsion fuel and the pulverized coal were burned separately, it was recognized that the initial purpose could be achieved by injecting the additive into the fuel.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described in detail above, the present invention uses ultra-heavy oil O / W type emulsion, mixed emulsion of O / W type and W / O type, and W / O type emulsion to use for pipe transportation and tanker. Can be handled in the same way as a liquid, such as loading of oil, transportation in a pipe to an oil storage tank, and by adding a combustion accelerator composed of Fe, Ba, Mn compounds and an anticorrosion additive composed of Ca or Mg compounds. In addition, it is possible to improve combustibility and reduce corrosion damage.

Furthermore, in the present invention, by adding pulverized coal to the above emulsion fuel, it is possible to improve the combustibility of both, and the effect of the corrosive action of the corrosive components in the combustion ash of both is offset by both corrosive components. Play.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an O / W type emulsion,
The figure is a diagram schematically showing a W / O type emulsion, FIG. 3 is a sectional view of a boiler to which the combustion method of the present invention is applied, and FIG. 4 is a test combustion facility used in Example 5 of the present invention. It is a figure which shows an outline.

Continuation of the front page (56) Reference JP-A-52-36104 (JP, A) JP-A-53-125410 (JP, A) JP-A-55-112925 (JP, A) JP-A-56-159291 (JP , A) JP 57-38890 (JP, A) JP 57-55995 (JP, A) JP 53-44328 (JP, B1) JP 56-15756 (JP, B1) JP 56-15758 (JP, B2) Japanese Patent Publication Sho 56-15680 (JP, B2)

Claims (3)

[Claims] 1. An O / W type emulsion, O / W type and W / O from fine particles of ultra-heavy oil and water that are grease-like at least at room temperature.
Type mixed emulsion or W / O type emulsion is prepared, and the combustion accelerator and Ca which consist of Fe or Mn compound are added to this.
Alternatively, a method of burning an ultra-heavy oil-water emulsion fuel, which comprises adding an anticorrosive additive comprising an Mg compound and burning the mixture. 2. O / W type emulsion, O / W type and W / O from fine particles of ultra-heavy oil and water that are grease-like at least at room temperature.
Type mixed emulsion or W / O type emulsion is prepared, and pulverized coal is added thereto and burned, which is a method for burning ultra heavy oil-water emulsion fuel. 3. O / W type emulsion, O / W type and W / O from ultra-heavy oil fine particles and water which are grease-like at least at room temperature.
Type mixed emulsion or W / O type emulsion is prepared, and pulverized coal and a combustion accelerator composed of a compound of Fe, Ba or Mn are added thereto, and the mixture is burned. Combustion method.