JPS6140718B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a mixed coal oil made of a mixture of pulverized coal and hydrocarbon oil, which is highly safe and does not cause sedimentation or coagulation over a long period of time. Since coal is a solid, it has traditionally been inferior to fuel oil, which is a liquid, as an energy source because it is difficult to transport and difficult to control during combustion. In order to overcome this problem and improve the suitability of coal as a fuel, various studies have been conducted on so-called mixed coal oil, which is made by pulverizing coal and dispersing it in fuel oil. In Japan, prior to World War II, research into so-called colloidal fuel, which was made by pulverizing coal and mixing it with petroleum, was being actively conducted at naval fuel depots and other locations. However, simply mixing pulverized coal with a normal particle size distribution and petroleum causes the coal particles to settle and separate due to the difference in specific gravity, creating a hard layer with no fluid conductivity.
In order to prevent this, methods have been considered to extremely slow down the sedimentation rate, such as by constantly stirring or by reducing the total amount of coal particles to 10 μm or less in diameter, but both methods are expensive and undesirable in practical terms. . On the other hand, in order to prevent pulverized coal from settling, many methods have been studied to produce stable mixed coal oil or emulsified mixed coal oil by adding stabilizers such as polymeric substances or emulsifiers and/or water to petroleum and pulverized coal. It has been. Typical stabilizers that have traditionally been used above include protective glues such as glue, gelatin, gum arabic, and starch, as well as paraffin, sericin, lanolin, petrolatum, and similar substances. Examples include wax, beef tallow, and wool tallow. However, none of these stabilizers were decisively effective with a certain degree of stabilizing power. Later, metallic fatty acid soaps were considered. The metals of these metal soaps include Al, Mn, Co, Zn, Ca, Na, K, Pb,
Mg, etc. were used, and fatty acids such as oleic acid, stearic acid, and valmitic acid were used. In addition, there is a method of adding an alkali to form a salt with humic acid in coal to prevent sedimentation of coal particles, and a method of using coal-based distillate such as anthracene, naphthalene, phenanthrene, etc. for the purpose of peptizing and dispersing coal particles. Tar oil containing phenols etc.
Numerous research examples have been reported in the past, including methods for producing stable mixed coal oil by adding appropriate amounts of anthracene oil, creosote oil, etc. Recently, an energy crisis has occurred due to production adjustments and high price offensives in oil-producing countries in the Middle East, which are major suppliers of coal resources.This has triggered calls for energy diversification worldwide, and The energy demand structure is being reviewed. Therefore, blended coal oil has also started to attract a lot of attention from the perspective of saving consumption of petroleum resources and making effective use of coal, and many examples of research and inventions have come to be seen. Some of these published materials include a method in which an electric field is applied to a heavy oil dispersion system of pulverized coal to reduce the sedimentation speed of pulverized coal by utilizing thickening due to the electrorheological effect, and the present inventor et al. previously applied for a method in which pulverized coal contains about 3% of ultra-fine coal with a particle size of 5μ or less to prevent large particles from contacting each other and make it difficult for them to settle densely, without using a stabilizer. Research has also been conducted on methods for producing stable mixed coal oils, but most of the research and invention examples use stabilizers for mixed coal oils, and most of them are related to research on stabilizers. Adding a large amount of stabilizer improves the stability of mixed coal oil, but it is a major factor in increasing costs, so it is necessary to stabilize the amount so that it can still function adequately even if the amount added is kept to a very small amount. The development of new agents is desired. For example, various imidazoline surfactants, bisamide compounds, ether amine derivatives, alkylphenol surfactants, the aforementioned metal soaps, metal salts of carboxyl group-containing hydrocarbons, polyethylene glycol nonionic surfactants, active hydrogen A wide variety of additives have been devised, including alkylene oxide derivatives of various compounds having It can be done. As mentioned above, research to date has focused on research on coal particles as a dispersoid and the development of stabilizers, and there has been little detailed research on fuel oil as a dispersion medium. . In general, hydrocarbons are broadly classified into paraffinic, olefinic, naphthenic, and aromatic hydrocarbons. Paraffinic hydrocarbons are saturated chain compounds represented by the molecular formula of CmH ₂ n+ ₂ (n = integer), and there are two types: unbranched n-paraffin and branched in-paraffin. The content of hydrocarbons is relatively high. In addition, olefinic hydrocarbons have only one double bond.
For example, in the case of one double bond,
It is a chain unsaturated hydrocarbon represented by the general formula CnH ₂ n (n=integer). Olefins are generally not present in crude oil. It is extremely rare in petroleum products other than gasoline. In addition, there are diolefins and cyclic olefins, but they are hardly contained in petroleum products. Naphthenic hydrocarbons are hydrocarbons containing at least one saturated ring in one molecule. Those that exist in crude oil and petroleum products are those in which two or three naphthene groups are linked together or fused with an aromatic ring, or in which various paraffin side chains are attached to naphthene rings or fused rings. There are some things. Aromatic hydrocarbons refer to hydrocarbons containing at least one aromatic ring in one molecule, and light distillates are mainly composed of benzene and monocyclic compounds with side chains attached to benzene. In addition, the main components of petroleum heavy fractions are polycyclic condensed aromatic compounds with two or three rings, and compounds containing both aromatic rings and naphthenic rings. Crude oil and kerosene, which we currently use as fuel;
As is clear from their component analysis, the components of light oil, A heavy oil, B heavy oil, C heavy oil, etc. mainly consist of paraffinic hydrocarbons, naphthenic hydrocarbons, and aromatic hydrocarbons, and almost no olefinic hydrocarbons are included. Not yet. In consideration of the above-mentioned circumstances, the present inventors prepared various hydrocarbon oils with compositions that had never existed before from petroleum fuel oil, and investigated the stability of mixed coal oil using these. As a result, the following results were obtained. It has been found that when a hydrocarbon oil having a certain composition is mixed with pulverized coal, an extremely stable mixed coal oil can be obtained without using expensive additives such as surfactants. That is, it has been found that a mixed coal oil with excellent stability can be obtained by mixing a hydrocarbon oil containing olefinic hydrocarbon at 5% by volume or more with pulverized coal. As the hydrocarbon oil, use is made of an olefinic hydrocarbon added to petroleum fuel oil that does not contain an olefinic hydrocarbon, or a hydrocarbon oil containing 5% by volume or more of an olefinic hydrocarbon. As an example of the former, olefinic hydrocarbons are
Examples of the latter include petroleum-based, coal-based,
It is possible to use cracked or modified oil sand or oil shale heavy hydrocarbon oils, or liquid oil obtained from oil shale. Petroleum-based fuel oils used in the present invention include petroleum-based fuel oils that are liquid at room temperature, such as crude oil, crude oil obtained by removing the gasoline fraction from crude oil, atmospheric residual oil, kerosene, light oil, A heavy oil, B heavy oil, C Examples include heavy oil. In the present invention, the olefinic hydrocarbon to be added to petroleum fuel oil needs to have a carbon number of 8 or more from the viewpoint of safety, and preferably has a boiling point (initial distillation point) of 150°C. Hydrocarbons of 10 or more are suitable, such as decene, undecene, dodecenes, etc. In addition, liquid oils containing a relatively large amount of olefinic hydrocarbons, such as those obtained by processes such as cracking, reforming, and carbonization, can also be used. The amount of olefinic hydrocarbon added to the petroleum fuel oil needs to be 5% by volume or more, and preferably 10% by volume or more, based on its contribution to the stability of the mixed coal oil. Examples of the heavy oil to be decomposed or modified include petroleum-based heavy oil such as asphalt, coal-based heavy oil, oil sand-based heavy oil, oil shale-based heavy oil, and the like. Note that various processes such as decomposition or modification include, for example, thermal decomposition, steam decomposition, catalytic decomposition, and the like. These cracked or reformed heavy oils contain at least 5% by volume of olefin hydrocarbons, and some contain 10% by volume or more, so they can be used as they are as the hydrocarbon oil in the blended coal oil of the present invention. can. In particular, the carbonized (retorted) crude oil obtained from oil siel, which can be used as it is as the hydrocarbon oil of the blended coal oil of the present invention, and the light oil and heavy oil obtained by fractionating it, have a carbon content of 20% or more by volume. Contains olefinic hydrocarbons ranging in number from 8 to 15. The exact mechanism of how olefinic hydrocarbons in hydrocarbon oils contribute to the stabilization of mixed coal oils is not clear, but olefinic hydrocarbons in hydrocarbon oils are more stable than saturated hydrocarbons. It is presumed that because of its strong polarity, it is selectively adsorbed on the surface of pulverized coal, and as a result, agglomeration and solidification of the pulverized coal particles are prevented and a stable mixed coal oil can be obtained. Furthermore, in order to improve the stability, very small amounts of various mixed coal oil stabilizers can optionally be added to the above mixed coal oil as dispersion aids. The pulverized coal used in the present invention is made from a Tyler 100 mesh sieve, which is normally used in large boilers.
It consists of finely powdered coal and/or petroleum coke with an average particle size of about 50 to 100 μm or less that passes through the filter. In addition, in order to obtain emulsified mixed coal oil using various hydrocarbon oils used in this application, such hydrocarbon oil 100
2 to 100 parts by volume of water are added to emulsify, optionally in the presence of an emulsifier, and the pulverized coal is dispersed therein. Emulsified mixed coal oil has a small amount of nitrogen oxides in the exhaust gas, so it can be used advantageously in terms of pollution control. However, if less than 2 parts of water is used in the above, the effect of reducing nitrogen oxides will be small; If more than 1 part is used, there is a problem with the stability of the emulsified mixed coal oil. Further, when an emulsified oil is produced by mixing water with a hydrocarbon oil, if an emulsifier is used, a more stable emulsified oil can be obtained, and the stability of the emulsified kelp oil can be improved. In the above, both synthetic and natural surfactants can be used as emulsifiers, and may also contain antifreeze agents, rust preventives, antifungal agents, and the like. The present invention will be explained below with reference to Examples, but these Examples are not intended to limit the present invention. In the following examples, coal shown in Table 1, petroleum fuel oil shown in Table 2, and heavy cracked oil and sierre oil shown in Table 3 were used.

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[Table] Example 1 100 g of pulverized lignite that passed 95.0% by weight through Tyler's 100 mesh sieve, 94 ml of A heavy oil, and 6 ml of 1-dodecene (carbon number 12) as an olefinic hydrocarbon were placed in a 300 c.c. beaker. The mixture was stirred and mixed for about 10 minutes using a stirrer equipped with a screw type rotor to obtain mixed coal oil A. On the other hand, for comparison, 100g of the above fine powder lignite was
Mixed coal oil B was obtained by stirring and mixing 97 ml of heavy oil and 3 ml of 1-dodecene in the same manner as above. Furthermore, mixed coal oil C was obtained by stirring and mixing 100 g of the pulverized lignite with 100 ml of heavy oil A in the same manner as described above. In each of the examples shown below, the degree of coal settling was measured by the maximum resistance force expressed in g when a steel ball with a diameter of 10 mm penetrates the mixed coal oil at a speed of 60 mm/min. If this value is large, mixed coal oil, pulverized coal, etc. will settle densely, indicating that it cannot be put to practical use. Table 4 shows the properties of the obtained mixed coal oil after being left at room temperature for 3 and 5 weeks. Example 2 100 g of finely powdered limestone coal that passed 83.8% by weight through Tyler's 100 mesh sieve, 94 ml of extracted oil, and 1-dodecene (carbon number 12) 6 as an olefinic hydrocarbon.
ml in a 300 c.c. beaker and stir and mix for about 10 minutes using a stirrer equipped with a screw type rotor to make mixed coal oil D.
I got it. On the other hand, for comparison, 100g of the above fine powder lignite
Mixed coal oil E was obtained by stirring and mixing 97 ml of oil and 3 ml of 1-dodecene in the same manner as described above. Furthermore, 100 ml of oil was added to 100 g of the finely powdered green coal by stirring in the same manner as described above to obtain a mixed coal oil F. Table 5 shows the properties of the obtained mixed coal oil after being left at room temperature for 3 and 5 weeks. Example 3 100 ml of heavy cracked oil obtained by decomposing 100 g of asphalt, which had passed through a Tyler 100 mesh sieve at 95.0% by weight, was placed in a 300 c.c. beaker.
The mixture was stirred and mixed for about 10 minutes using a stirrer equipped with a screw type rotor to obtain mixed coal oil G. On the other hand, for comparison, mixed coal oil H was obtained by stirring and mixing 100 g of the fine powdered lignite and 100 ml of hydrogenated heavy cracked oil in the same manner as above. Table 6 shows the properties of the obtained mixed coal oil after being left at room temperature for 3 weeks and 5 weeks. Example 4 100 g of finely powdered lignite that passed 95.0% by weight through Tyler's 100 mesh sieve, 100 grams of siere oil (crude oil)
ml was placed in a 300 c.c. beaker and stirred and mixed for about 10 minutes using a stirrer equipped with a screw type rotor to obtain mixed coal oil I. On the other hand, for comparison, the fine powder lignite
Mixed coal oil J was obtained by stirring and mixing 100 g and 100 ml of hydrogenated sierre oil in the same manner as described above. Table 6 shows the properties of the obtained mixed coal oil after being left at room temperature for 3 and 5 weeks. As is clear from Tables 4 to 6, the blended coal oils of the present invention both had a higher
It is clear that the product has excellent stability as it does not solidify after being left standing for a long period of time.

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Claims (1)

[Scope of Claims] 1. 5 to 5 olefinic hydrocarbons having 8 to 15 carbon atoms
A mixed coal oil characterized by dispersing pulverized coal in a hydrocarbon oil containing 35% by volume. 2. The mixed coal oil according to claim 1, wherein the hydrocarbon oil is obtained by adding a predetermined amount of the olefinic hydrocarbon to a natural petroleum oil. 3. The mixed coal oil according to claim 1, wherein the hydrocarbon oil is obtained by decomposing or reforming heavy oil. 4. The mixed coal oil according to claim 1, wherein the hydrocarbon oil is obtained from oil siel.