JPH0477035B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to the improvement of a pulverized coal-oil mixed fuel composition used as a liquid fuel, which is made by suspending and stabilizing fine coal powder in petroleum-based heavy oil. Currently, most of the world's energy is provided by oil, but there are limits to the reserves of oil resources, and there is a possibility that in the near future it will not be able to meet the increasing demand for energy. Coal has recently been attracting attention as an energy source to replace oil. Coal is considered to be an extremely promising resource due to its abundant reserves and the wide range of production areas. When coal is mined, it is in the form of lumps and difficult to handle, so it is being considered to turn it into pulverized coal, suspend it in heavy petroleum oil, and use it as a liquid fuel. PRIOR ART If coal is simply suspended in heavy oil, the suspension is unstable and pulverized coal tends to precipitate over time. It is known that pulverized coal can be stabilized by reducing its particle size and ultrafinely pulverizing it to 0.1 to 10μ, but ultrafinely pulverizing it is not easy.
It was economically disadvantageous. Therefore, we used pulverized coal that was crushed to about 200 mesh pieces.
The suspension is stabilized by adding it to heavy oil and suspending it, and adding additives such as surfactants to this. Additives conventionally used for this purpose include various fatty acids and soaps, a combination of lead oleate and alkali, soft or hard sodium dodecylbenzenesulfonate, and EDTA.
derivatives, dialkyl sulfosuccinic acid, octadecyl betaine, polyethylene polyamine-based copolymerized multichain type high molecular weight nonionic surfactants, sorbitol-propylene oxide-ethylene oxide copolymerized nonionic surfactants, etc. are used. Problems to be Solved by the Invention However, additives that can be used in pulverized coal oil mixed fuel compositions are expensive and economically disadvantageous. The present invention was made in view of the above circumstances, and provides an additive that is inexpensive, effectively prevents separation of the composition, keeps the viscosity low, and obtains a composition with good dispersion stability. The purpose is to Means for Solving the Problems Accordingly, the present invention provides a mixture of 40 to 60 parts by weight of coal powder and 40 to 60 parts by weight of petroleum-based heavy oil to 95 to 99.5% by weight of tall oil or tall oil as an additive. It is characterized by the addition of 0.5 to 5% by weight of oil fatty acids. Coal generally has different compositions and characteristics depending on its production area. Miike charcoal, which has a low moisture content, is most suitable for use in the composition of the present invention, and the effect of stabilizing dispersion according to the present invention is most significant, but coal from other regions can also be used. It is possible and sufficiently effective. The moisture content in the coal is preferably as low as possible. If the water content is high, the coal tends to settle over time, which is not preferable. Therefore, even when using the Miike charcoal, it is preferable to dry it before preparing the composition. However, when the moisture content is high, even if the coal settles over time, the settled coal will not solidify at the bottom of the composition liquid, and will be easily homogenized by light stirring, so that it can be used as a liquid fuel. The moisture content in the coal is not an essential requirement of the present invention, as it does not interfere with its use. As the heavy oil, ordinary C heavy oil can be used, and there are no problems depending on the production area. The ratio of coal powder to heavy oil is 40 to 60
%, heavy oil can be used in the range of 40 to 60%, and both are usually mixed in approximately equal amounts. The amount of coal powder is 40%
If the amount is below, the amount of coal will be small and the meaning of reducing oil consumption by using a mixed fuel will be lost. Further, even if the amount is 60% or more, a sufficiently stable composition can be obtained according to the present invention, but the viscosity of the composition becomes too high and handling becomes difficult. The amount of tall oil or tall oil fatty acid added in the composition of the present invention is 0.5 to 5
Weight % is appropriate. In addition, hereinafter, when referring to tall oil in this specification, tall oil fatty acids are also included. The appropriate amount of tall oil to be added differs depending on the region of coal production; with Miike charcoal, a sufficiently stable composition can be obtained at 0.5 to 1% by weight, but if coal from other regions is used. In some cases, 2 depending on the place of origin.
It is necessary to increase the amount to ~5% by weight. The appropriate amount of addition also varies depending on the particle size of the coal powder, and when the particle size is large, it is necessary to increase the amount of tall oil added. However, once the required amount of tall oil is added depending on the origin and particle size of the coal powder, the effect will not increase even if the amount of tall oil added is increased further. To prepare the compositions of the present invention, approximately 70% of the heavy oil
It is prepared by heating to about 0.degree. C., adding a predetermined amount of tall oil and coal powder, and stirring with a stirrer for about 3 minutes. Water can be added in small amounts when preparing the composition. A predetermined amount of tall oil and 0.1 to 3% by weight of water based on the entire composition are added to heavy oil to homogenize it, and a predetermined amount of coal powder is added to this and stirred,
Prepare the composition. Although the composition obtained in this way has a slightly higher viscosity than one without the addition of water, it has less settling of coal powder and is less likely to change over time, making it an extremely excellent fuel composition. Become a thing. This fact contradicts the fact that a high water content in coal powder is undesirable as mentioned above, and the behavior of water in the composition is not clear. Effect In the composition of the present invention, higher fatty acids and resin acids in tall oil adsorb or react with ash or basic groups in coal, making the surface of coal lipophilic and having an affinity for heavy oil. It is thought that the stability of the composition is increased due to better properties. Further, in the present invention, the sedimentation property is improved by adding water to the composition, but its effect is not clear. Effects of the Invention The pulverized coal oil mixed fuel composition obtained by the present invention maintains good stability over a long period of time, and the coal powder in the composition inhibits the fluidity of the composition. It does not settle and has a low viscosity, making it easy to handle. In particular, in the composition to which water is added in the second invention, coal sedimentation is particularly low, and even if the initial water content of the coal powder is somewhat high, a high degree of stability can be maintained for a long period of time. . Furthermore, tall oil is obtained as a by-product during pulp production and is inexpensive, allowing the composition to be produced at low cost. Example Mixed pulverized coal of sample: Miike charcoal was used as the coal powder used in the test, and samples using Minami-Oyubari charcoal, Warara charcoal, Taiheiyo charcoal, and Akahira charcoal were also tested to determine the influence of coal production area. saw. In addition, the particle size of pulverized coal is less than 200 mesh.
Based on a mixture (A) of 20% by weight and 120 to 200 meshes, tests were also conducted on 100% of 200 mesh or less (B) and 100% of 350 mesh or less (C) to examine the effect of particle size. . The moisture content of pulverized coal was adjusted to approximately 0.5% by drying it in a desiccator.
Tests were also conducted at concentrations of 1.0% and approximately 1.5%. In addition, in order to understand the effect of adding water to the composition in the second invention of the present application, pulverized Miike charcoal containing about 1.5% water was used, and 0.3% by weight of the entire composition, 0.8% by weight of the entire composition. wt% and 1.8wt%
Compositions with added water were also tested. Heavy oil: Arabian Light atmospheric distillation residue oil was used as the petroleum heavy oil used in the composition. Additive: As an additive, tall oil fatty acid (Harima Kasei Kogyo Co., Ltd. Hartol FA-3S (fatty acid
88.1%, resin acid 7.4%, unsaponifiables 4.5%)), and the amount added was 1% by weight. %, 3% by weight and 5% by weight were also tested. For comparison, a commercially available surfactant containing sodium dodecylbenzenesulfonate as its main component (Neoperex No. 1F Powder manufactured by Kao Soap Co., Ltd.) was used at 0.2
Tests were also conducted with weight percent additions. Blending ratio: 50% by weight of pulverized coal, specified amount of tall oil fatty acids,
The remainder was made into heavy oil. However, for those to which water was added, the total of pulverized coal and water was 50% by weight. In addition, in order to examine the possibility of increasing the amount of pulverized coal, we increased the amount of tall oil fatty acids to make pulverized coal 52.5% by weight.
Tests were also conducted at 55% by weight, 57.5% by weight, and 60% by weight. Sample preparation: For formulations that do not add water, prepare the sample by adding the specified amount of tall oil fatty acids and pulverized coal to heavy oil heated to 70℃, and stirring for 3 minutes with a bladed stirrer. did. For formulations with added water, add the specified amount of tall oil fatty acids and water to heavy oil heated to 70℃, stir for 1 minute with a high-speed Chemitron to homogenize, and then add the specified amount of fine powder. Samples were prepared by adding charcoal and stirring for 3 minutes with a bladed stirrer. Test Items Composition Stability Test Rod Penetration Test: The sample composition was placed in a glass cylinder with an inner diameter of 38 mm to a depth of 210 mm,
This is immersed in a constant temperature bath at 70°C and left. After a predetermined period of time, a glass rod with a diameter of 5 mm and a weight of 20 g was dropped vertically from the liquid surface, and the percentage of the depth to which the glass rod penetrated into the sample was measured as the penetration rate. In the case of 100% penetration, the time (seconds) required for penetration was measured and taken as the penetration time. In this test, if the penetration rate is 100%, no hard sedimentary layer is formed at the bottom, and the flow is not actually inhibited. Also, the shorter the penetration time, the better. Sedimentation measurement of specific gravity of each layer: Put the composition into a glass cylinder similar to the above rod penetration test, leave it at 70°C for a predetermined time, divide the composition into three equal parts: upper layer, middle layer, and lower layer. Approximately 10 ml was taken out from the center and its specific gravity was measured using a pycnometer. Viscosity: The viscosity of the sample composition at 70°C was measured using a coaxial rotating double cylinder viscometer (rheometer IR-200 manufactured by Iwamoto Seisakusho Co., Ltd.). To see the thixotropic properties of the composition, the rotational speed is
It was raised and lowered at a constant speed of 50 rpm (shear rate 22/sec) for 2 minutes, and the shear stress was continuously recorded.
Thereafter, it was rotated at 50 rpm for 5 minutes, and the viscosity (Pascal/second) was measured. Test Results Table 1 shows the composition of the samples tested, and Table 2 shows the test results.

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[Table] According to the above test results, in the case of formulations without additives, Miike charcoal with small pulverized coal particle size and low water content, and in the best condition. As shown in sample 1, the rod penetration rate has already increased 7 days after sample preparation.
It did not reach 100%, and the difference in specific gravity between the upper and lower layers of the sample became large, indicating that the pulverized coal in the sample had settled significantly. Therefore, such a composition cannot be said to be of any use as a liquid fuel. On the other hand, in Standard Sample 3 of the present invention, despite the large particle size, the rod penetration rate was 100% even after 15 days, and the penetration time was short. Furthermore, the difference in specific gravity between the upper and lower layers is small, and the viscosity is also low. Sample 2 with added tall oil fatty acid amount of 0.5%
Although the rod penetration rate after 15 days did not reach 100% and could not be said to be sufficient, it was still usable for 7 days. In addition, in samples 4 and 5 in which the amount of tall oil fatty acid added was increased to 3 to 5%,
The results were not much different from Sample 3, and once the required amount of tall oil was added, no improvement in effectiveness could be expected even if the amount was increased further. In samples 6 and 7, in which the particle size of the pulverized coal is small, although the viscosity is slightly higher, the rod penetration time is shorter and the difference in specific gravity between the upper and lower layers is also small. It can be understood that this improves the effect even more. 350
If pulverized coal of 100% less than mesh is used, it can be assumed that even 0.5% of tall oil is sufficient. Moisture contained in pulverized coal has an adverse effect on the effects of the present invention. In samples 8 and 9, which used pulverized coal with a high moisture content, the rod penetration rate was
Although it is 100%, the penetration time is longer,
The difference in specific gravity between the upper and lower layers is also large, indicating that the pulverized coal is settling heavily. However, the viscosity of the composition was low, indicating that the bonds between the particles of the settled pulverized coal were weak, and that it was easily stirred and dispersed by the rotation of the cylinder of the viscometer. Therefore, it is considered that it can be used satisfactorily unless long-term stability is particularly required. Samples 10, 11, and 12 show examples in which water was added to the composition in the second invention of the present application. As is clear from the test results for this sample, even after 15 days had passed since sample preparation, the rod penetration time was extremely short, and the difference in specific gravity between the upper and lower layers was also extremely small. Therefore, although the basis for this is unknown, by adding a small amount of water,
It can be seen that a composition with extremely good stability can be obtained. For those using pulverized coal other than Miike charcoal, as shown in samples 13 to 16, even if 3% tall oil was added, the effect was inferior to that of Miike charcoal. When Minami-Oyubari charcoal is used, it is almost as effective as Miike charcoal, but with Warafu charcoal and Akahira charcoal, it is barely usable after 7 days, but after 15 days. In this case, the rod penetration rate has not reached 100%. There is also a large difference in specific gravity between the upper and lower layers. With Taiheiyo Coal, the rod penetration rate has not yet reached 100% after seven days. However, even with these pulverized coals other than Miike charcoal, the stability is significantly increased compared to those formulated without tall oil, and by further increasing the amount of tall oil added or adding water, There is a possibility of obtaining a usable formulation. Moreover, if the storage period is short, the product can be used sufficiently. In addition, when Miike charcoal is used and its blended amount is increased, as shown in samples 17 to 20, the viscosity becomes higher and the rod penetration time becomes longer, but the rod penetration rate is 100%. Furthermore, the difference in specific gravity between the upper and lower layers is small, and the stability of the composition can be said to be sufficiently high. It is natural that the higher the solid content concentration of a suspension of powder, the higher the viscosity, and the longer the rod penetration time. Despite this, the rod penetration rate is 100%, there is little sedimentation of pulverized coal in the composition, and the composition is sufficiently stable and can be used as a liquid fuel. However, in this case, it is necessary to increase the amount of tall oil added in accordance with the increase in the amount of pulverized coal. However, the amount of pulverized coal
Even in the case of 60%, adding 5% of tall oil is sufficient, and adding 10% does not further improve stability as shown in sample 21. For comparison, Sample 22 shows an example using a conventional surfactant as an additive, but the product of the present invention is comparable to this, and the viscosity is actually lower. It can be seen that the present invention has extremely excellent stability as a pulverized coal oil mixed fuel composition.

Claims (1)

[Claims] 1. 40 to 60 parts by weight of coal powder and 40 to 60 parts by weight of petroleum-based heavy oil.
A pulverized coal oil mixed fuel composition, characterized in that 0.5 to 5% by weight of tall oil or tall oil fatty acid is added to 95 to 99.5% by weight of the mixture with parts by weight. 2. The pulverized coal oil mixed fuel composition according to claim 1, wherein the coal is Miike charcoal. 3 40-60 parts by weight of coal powder and 40-60 parts by weight of petroleum-based heavy oil
92 to 99.4% by weight of the mixture with parts by weight, 0.5 to 5% by weight of tall oil or tall oil fatty acids, and 0.1% of water.
-3% by weight of the pulverized coal/oil mixed fuel composition 4. The pulverized coal/oil mixed fuel according to claim 3, wherein the coal is Miike charcoal. Composition.