JPH09302360A - Additive for petroleum-based fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an additive for petroleum-based fuels, comparable to aqueous acetate solution in terms of corrosive wear preventiveness and free from concern for the stay of e.g. heavy oil in fuel pipings and the wear and clogging troubles in burner nozzles, and to provide a method for burning the petroleum- based fuels containing this additive. SOLUTION: This additive for petroleum-based fuels comprises an oil slurry, water slurry or water-oil emulsion slurry containing a surfactant and at least one kind of compound selected from magnesium citrate, calcium citrate and cerium citrate. The citrate content is pref. 20-80wt.% of the whole amount of the additive (on an anhydrous basis) preferable in its handling. The citrate crystal after dried in the form of anhydrous crystal and/or crystal water-contg. crystal is <=2μm in average particle size. A method for burning fuel is as follows: 10-1,000ppm, on an anhydrous basis, of this additive is added to a petroleum-based fuel on the upstream stage of a burner to conduct the fuel's burning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler using petroleum-based fuel, an additive for petroleum-based fuel used in a furnace and the like, and a method for burning a petroleum-based fuel by adding the additive to a petroleum-based fuel for combustion.

[0002]

2. Description of the Related Art Petroleum-based fuels are widely used in boilers, furnaces and the like. However, since petroleum-based fuels contain various corrosive compounds containing elemental compounds such as sodium (Na), sulfur (S), and vanadium (V) as main components, they are used as combustion gas of petroleum-based fuels. High-temperature structural members such as boilers and furnaces that come into direct contact are subject to significant corrosion damage. Various additives have been developed for the purpose of preventing and suppressing these, and magnesium, calcium, barium, and cerium are mainly known as elements. There are various forms of the additive such as an oxide slurry, an oil slurry of hydroxide, a water slurry and an oil-dissolved type. The slurry mainly consists of inorganic oxides such as MgO and MgCO ₃ , hydroxides, carbonates and the like, and organically coated types. Examples of organic oil-soluble types include petroleum sulfonates and fatty acid salts, which are extremely expensive and have extremely excellent performance, but their use range is limited.

Further, additives for boilers of aqueous solutions of acetates such as magnesium acetate, calcium acetate and cerium acetate are widely used. Aqueous solutions of these acetates, formates, and nitrates decompose when exposed to temperatures of 300 ⁰ C or higher and become gasified substances and solid oxides. It is widely known that during this decomposition, it is broken into ultrafine particles of magnesium oxide, calcium oxide, and cerium oxide, which are active ingredients, and has extremely high activity and excellent performance. However, it acetates because gelation and melted 80 to 120 ⁰ C, accumulates in the fuel pipe such as heavy oil, there is a risk of wear and blockage failures banner nozzle and giant particles of. The aqueous solutions of formate and nitrate are not usually used as boiler additives for the following reasons. Formate is highly toxic, becomes a poisonous deleterious substance in handling, is highly dangerous, and is not preferable in use. Nitrate is also toxic, and at the same time, it is difficult to use in a high temperature environment in which anhydrous nitrate is mixed with organic matter, because of danger of ignition or explosion.

[0004]

The function of preventing and suppressing corrosion wear due to various corrosive compounds in petroleum-based fuel is equivalent to that of an aqueous solution of acetate salt, and is retained in fuel pipes such as heavy oil and nozzles for banners. The present invention provides an additive for petroleum-based fuel, which does not cause wear and clogging failure of the fuel, and a method for burning petroleum-based fuel using the additive.

[0005]

The present invention is directed to an oil slurry, a water slurry or a water-oil emulsion slurry of one or more selected from the group consisting of magnesium citrate, calcium citrate and cerium citrate and a surfactant. Is an additive for petroleum-based fuels. The content of the one or more citrate salts is preferably 20-80% by weight of the total weight of the additive, as an anhydrous salt. The content of 20 to 80% by weight is preferable in handling the additive for petroleum-based fuel. Part 1
The citrate crystals of one or more species preferably have an average particle size of 2 μm or less as anhydrous crystals and / or crystals containing water of crystallization when dried. If the average particle size is larger than 2 μ, it may remain unnecessarily inside the boiler, leading to a decrease in boiler efficiency and a decrease in operating rate.

[0006] The magnesium citrate, with nonahydrate salt (colorless columnar crystals) room temperature, the anhydrous salt at 175 ⁰ C. At room temperature, tetradecahydrate (colorless leaf crystals) becomes a trihydrate at 110 ⁰ C and is further heated to an anhydrous salt. Regarding calcium citrate, the tetrahydrate (colorless needle crystals) at room temperature is 100 to 1
A dihydrate is obtained at 30 ⁰ C and an anhydrous salt is obtained at 175 to 185 ⁰ C.
Cerium citrate is a 3.5-hydrate, colorless crystal at room temperature.

Further, in a boiler, a furnace or the like using a petroleum-based fuel, 10 to 1000 ppm (as an anhydrous salt) of the above-mentioned petroleum-based fuel additive based on the weight of the petroleum-based fuel is used upstream of the burner. It is a method for burning petroleum-based fuel that is added to system fuel and burned. When the content is less than 10 ppm, the obtained effect tends to be insufficient, while on the other hand, when the amount is more than 1000 ppm, the effect obtained tends not to be improved.

It has been recognized that the oxides of magnesium, calcium and cerium produced from additives for petroleum fuels cause the temperature of exhaust gas to rise abnormally due to the phenomenon of whitening of the piping inside the boiler. In order to prevent the exhaust gas temperature from rising abnormally, an oil-soluble organic iron salt, such as iron petroleum sulfonate, is used as Fe ₂ O _{3 in an amount} of 10 to 20% by weight as Mg ₂ O ₃ which is an additive for petroleum fuels. Was added to obtain the effect of suppressing the rise in exhaust gas temperature.

[0009]

DETAILED DESCRIPTION OF THE INVENTION Magnesium citrate, calcium citrate, and cerium citrate have a specific gravity of 1.5 to 1.
It is as low as 7, which is more stable than conventional oil slurries, has less accumulation in containers and storage tanks, and can be used for one year without defective injection. Further, since the citrate salt is hardly dissolved in water, it can be made into a slurry without trouble as compared with other organic acid salts. Table 1 shows the results of comparison in which various slurries and aqueous solutions were put in a 200 L commercially available ordinary drum and left outside for 60 days.

[0010]

[Table 1] In the conventional MgO oil slurry, about 30 mm is deposited on the bottom of the drum, and in addition, clay-like deposits are difficult to disperse, and it is very difficult to suck it with a pump. The citrate slurry of the present invention has a small amount of deposit, and can be easily redispersed and easily sucked by a pump. From this result, it is confirmed that the stability of the citrate slurry of the present invention is much higher than that of the conventional MgO oil slurry.

The reason why the citrate slurry of the present invention is equivalent to the acetate aqueous solution type in terms of the function of preventing and suppressing the corrosive wear due to various corrosive compounds in petroleum-based fuels is that the citrate slurry has It is considered that the decomposition gas and the combustion of the decomposition gas cause the crystals to explosively become finer and have the same particle size as that of the aqueous acetate solution type. However, citrate decomposes at about 250 ⁰ C or higher, as 80 to 120 ⁰ without even accumulated in the fuel pipe such as heavy oil may be gelled by melted in C of acetate, macroparticle There is no risk that it will wear out and cause obstruction of the banner nozzle.

By adding the citrate slurry of the present invention to petroleum-based fuel, suppression of corrosion (vanadium attack, sulfur attack) and melt adhesion (deposit, slacking) in the high temperature part of the boiler, and SO ₃ and virgin are suppressed. A generation suppression effect is obtained. An oil-soluble organic iron salt, such as iron petroleum sulfonate, may be added to the additive to obtain an effect of suppressing an increase in exhaust gas temperature. Hereinafter, the present invention will be described in detail with reference to Examples.

[0013]

【Example】

Example 1 In this example, various additives were continuously added to the boiler by a piston-type proportional injection pump into the C heavy oil line upstream of the burner. An actual boiler test was carried out for the effect of suppressing the corrosion and slug adhesion of the high temperature part (material: SUS29HTB) of the boiler by heavy oil C. Table 2 shows the results. 1. Boiler specifications for test Type Once-through type Evaporation amount 1510 T / H Steam temperature 543 ⁰ C Steam pressure 268 Kg / cm ² · g 2. Properties of C heavy oil S content 1.6% V content 45 ppm Na content 20 ppm Residual carbon content 10% 3. Operation status during the test: Load 80% Boiler outlet O ₂ 1.2% Air preheater outlet gas temperature 140 ⁰ C

[0014]

[Table 2] From Table 2, it is recognized that the citrate slurry of the present invention has the same excellent suppressing effect on the amount of thinning of the high temperature portion and the amount of slug adhesion as in the Mg acetate aqueous solution.

Example 2 In this example, an actual boiler test was conducted for the effect of suppressing the generation of SO ₃ and benzine under the same conditions as in Example 1 using various additives. The results are shown in Tables 3 and 4.

[0016]

[Table 3]

[0017]

[Table 4] From Tables 3 and 4, the effect of suppressing the generation of SO ₃ and benzine was also confirmed by the citrate slurry of the present invention.
It is recognized that an excellent suppressing effect equivalent to that of a salt aqueous solution can be obtained.

Example 3 In order to prevent an abnormal rise in exhaust gas temperature due to the whitening phenomenon of the pipe inside the boiler due to the oxides of magnesium, calcium and cerium produced from the petroleum-based fuel additive, in this example, , An oil-soluble organic iron salt such as iron petroleum sulfonate (based on MgO of petroleum-based fuel additive in terms of weight basis) is added to various additives, and the exhaust gas temperature rises under the same conditions as in Example 1. The inhibitory effect over 2 months,
I did a real boiler test. Table 5 shows the results.

[0019]

[Table 5] From Table 5, the Mg acetate aqueous solution and the Mg citrate oil slurry of the present invention have the same effect as the case of mixing the conventional MgO oil slurry with 10 wt% Fe ₂ O ₃ iron-based colorant based on MgO. Has been obtained. When 10 wt% Fe ₂ O ₃ was mixed with MgO of the Mg citrate slurry of the present invention, no increase was recognized.

[0020]

As described in detail in the above embodiments, the addition of the citrate slurry to the petroleum fuel suppresses the corrosion and melt adhesion of the high temperature part of the boiler, and suppresses the generation of SO ₃ and virgin. Is obtained. Incidentally, an oil-soluble organic iron salt such as iron petroleum sulfonate is further added to the additive,
The effect of suppressing the rise in exhaust gas temperature can be obtained.

Claims (5)

[Claims] 1. An oil slurry, water slurry or water containing at least one selected from the group consisting of magnesium citrate, calcium citrate and cerium citrate and a surfactant.
Additive for petroleum fuels consisting of oil emulsion slurry. 2. The content of one or more selected from the group consisting of magnesium citrate, calcium citrate, and cerium citrate as an anhydrous salt is 20 to 8 of the total weight of the additive.
The additive for petroleum fuel according to claim 1, which is 0% by weight. 3. An average particle diameter of anhydrous crystals and / or crystals containing water of crystallization is obtained by drying one or more citrate crystals selected from the group consisting of magnesium citrate, calcium citrate and cerium citrate. The additive for petroleum-based fuel according to claim 1 or 2, which has a particle size of 2 μm or less. 4. A boiler, a furnace or the like using a petroleum-based fuel, wherein the additive for petroleum-based fuel according to any one of claims 1 to 3 is contained in an amount of 10 to 1000 ppm (an anhydrous citrate salt based on the weight of the petroleum-based fuel). As) is added to the petroleum-based fuel upstream of the burner and burned. 5. The method for burning petroleum-based fuel according to claim 4, further comprising an oil-soluble organic iron salt as Fe ₂ O _{3 based on} MgO of the additive for petroleum-based fuel according to claims 1 to 3 on a weight basis. A method for burning petroleum-based fuel, comprising adding 20 wt% to an additive for petroleum-based fuel.