JP3787192B2 - Method for producing high concentration porous coal slurry - Google Patents

Description

【００６１】
表１から分かる様に、スラリー状態で脱水した比較例１〜３に比べ、実施例１，２は高濃度のスラリーが得られた。尚、比較例１〜３は、静置分離等をすることによって更に濃縮することが可能である。
【００６２】
また脱水の程度に関して、実施例１，２は十分に脱水されており、むしろ比較例１〜３よりも良好に脱水できた。褐炭に残留する媒体油については、比較例１〜３に比べ、実施例１，２は残留媒体油が少なく、従って、実施例１，２は少なく媒体油を残留させながらも良好に脱水できるということが分かる。
【００６３】
【発明の効果】
本発明に係る高濃度多孔質炭スラリーの製造方法においては、原料多孔質炭を効率良く脱水し、高濃度の多孔質炭・媒体油スラリーを得ることができる。加えて、この製造方法における使用媒体油の総量を少なくすることができ、従って、高粘度スラリーポンプ使用台数の削減等、設備の簡略化を図ることができ、またエネルギー効率を顕著に向上させることができる。
【００６４】
前述の様に、脱水多孔質炭スラリーは、その後表面の媒体油が除去され、脱水多孔質炭（固形燃料）とされるが、高濃度スラリーの場合は、媒体油の除去を低エネルギーで小型の設備で容易に行うことができるから、本発明の様に高濃度多孔質炭スラリーを得ることは有効である。しかも、媒体油が除去された上記脱水多孔質炭は、自然発火の抑制された良好な固形燃料である。尚、媒体油に重質油が含まれている場合は、上記高濃度スラリーから媒体油を除去すると、脱水多孔質炭には重質油のみが残留することになるが、この様に重質油が選択的に残された脱水多孔質炭も、自然発火の抑制された良好な固形燃料である。
【００６５】
また本発明においては従来法▲５▼と異なり、高温に保持した媒体油中に褐炭が直接投入されるから、熱損失が無く、しかも水分の沸騰時に粒子が激しく運動し、加えて循環媒体油で分散を図ることができるから、撹拌等の設備の必要がない。
【００６６】
また、沸騰がおさまった多孔質炭粒子は、自動的に沈降して濃縮されるから、従来の様な濃縮分離工程を省略することができ、更なる設備の簡略化を図ることができ、またエネルギー効率を向上させることができる。
【００６７】
また、本発明においては、多孔質炭粒子の昇温や水分の沸騰が急激に起こるから、脱水後の褐炭に含浸される媒体油量が減少し、従って消費する媒体油量を少なくすることができる。多孔質炭に含浸された媒体油は、機械的に回収することは難しく、従ってそのほとんどを蒸発回収することになるが、含浸される媒体油量が少なくなれば、後工程の媒体油回収工程の負荷が低減され、エネルギー効率の向上に寄与する。
【図面の簡単な説明】
【図１】本発明に係る高濃度多孔質炭スラリーの製造方法を実施する為の装置の一例を示す概念図。
【図２】本発明に係る高濃度多孔質炭スラリーの製造方法を実施する為の装置の他の例を示す概念図。
【符号の説明】
１，１０ 容器
２ ポンプ
３ 圧縮機
４ 媒体油回収工程
１１，２１ 上部円筒
１２ 下部円筒
１３ 上コーン部
１４ 下コーン部
１５，１７，２６ パイプ
１６ 抜き出し口
１８，１９，２７，２８，２９ 熱交換器
２５ 羽根部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for making a solid fuel excellent by dehydrating porous coal, which is low-grade coal because it contains a large amount of water, using a high-temperature oil component. This invention relates to a method for producing a high-concentration porous charcoal slurry in which the amount of use is reduced and the energy efficiency is improved. If oil is removed from the high-concentration porous coal slurry obtained here, a solid fuel is obtained.
[0002]
[Prior art]
Porous coal tends to contain a lot of moisture, for example, as much as 30 to 70% by weight due to its porosity. For porous coal with such a high water content, for example, even if it is intended to be transported to an industrial area, it is equivalent to transporting moisture, so the transportation cost is high and it is used near the mountain. The fact is that there is nothing else to do. A typical example of such a high moisture content porous coal is lignite.
[0003]
Some lignites have desirable properties such as low ash and low sulfur, but as mentioned above, the moisture content tends to be high due to their porosity, and when the moisture content exceeds 30%. Since the transportation cost becomes very high and the calorie per unit weight is reduced by the amount of water content, the low-grade coal is evaluated in spite of the above preferred properties. In addition to brown coal, lignite and subbituminous coal have similar problems.
[0004]
Therefore, hereinafter, the case of lignite may be described as a representative example, but the application target of the present invention covers all porous coals such as lignite and subbituminous coal. As lignite, there are Victoria charcoal, North Dakota charcoal, Belga charcoal and the like, and any porous coal having a high water content is applicable to the present invention regardless of the production area.
[0005]
Conventionally, techniques for reducing the moisture content of lignite and using it as a solid fuel have been studied. Among these, dry evaporative dehydration methods such as the tubular dryer method (conventional method ▲ 1) ▼) and non-evaporation type dehydration methods (conventional method {circle around (2)}) such as a miller process are known.
[0006]
However, the tubular dryer method of the conventional method (1) consumes a great deal of heat energy for drying, and the resulting dried lignite is porous and has a large active surface area. There is a danger of spontaneous ignition accidents due to oxygen adsorption and oxidation reaction, and there is a practical problem that storage and transportability are poor.
[0007]
In addition, since the miller process of the above conventional method (2) performs high-pressure operation, the cost of manufacturing and maintaining equipment suitable for this operation is high, and the high-pressure operation itself is difficult and complicated. In addition, this method has a problem of wastewater treatment. Furthermore, the dewatering rate of the dehydrated porous coal obtained by the conventional method (2) is poor, and the suppression of spontaneous ignition is not sufficient.
[0008]
On the other hand, as a method of suppressing spontaneous ignition, the surface of the porous coal is coated with tar, asphalt, mineral oil, etc., by compressing the porous coal to reduce the contact surface with air (conventional method (3)), A method for preventing contact with air (conventional method (4)) has been proposed.
[0009]
Therefore, for example, a safe lignite briquette production method without the risk of ignition has been proposed by combining the conventional method (1) and the conventional method (3), but recovering energy consumed for water evaporation during dehydration. Therefore, there is a problem that the thermal efficiency is low, and in addition, there is a problem that it is difficult to say that the suppression of pyrophoricity is completely achieved.
As another method, the following method has been proposed as a method for obtaining dehydrated porous charcoal by adding the conventional method (4) after dehydration by the conventional methods (1) and (2).
[0010]
JP-B-63-61358 (conventional method (4) -1): Sprayed a mixture of aromatic hydrocarbons and asphalt on the previously dehydrated lignite to prevent dust generation and increase the calories Technology.
[0011]
JP-B-7-47751 [Special Table 63-503461] (conventional method (4) -2): Steam is obtained by dipping and heating low-grade massive coal crushed to 0.5 to 1.5 inches in oil. The coal is separated from the coal while the steam is still being released from the coal, and the oil is removed from the wet coal, and the coal is covered with the residual oil. It will be in a state and its spontaneous ignition will be suppressed.
JP-A-61-238889 (conventional method {circle around (4)}-3): This is a method in which lignite and the like are reformed by dry distillation, and the generated lignite and the like are covered with the generated tar.
[0012]
However, all of the above conventional methods (4) -1 to 3 have high energy intensity and are complicated to operate, and the above conventional method (4) -1 often has a non-uniform asphalt coating. Problems remain, such as the effect of suppressing the ignitability may be insufficient.
Accordingly, as a new manufacturing method for solving these problems, the invention of Japanese Patent Laid-Open No. 7-233383 has been proposed (conventional method {circle around (5)}).
[0013]
In the conventional method (5), a porous charcoal and a medium oil are stirred and mixed to prepare a slurry, and the slurry is heated to 100 to 250 ° C. to evaporate and separate moisture in the porous charcoal. Separated to obtain dehydrated solid fuel. The medium oil used in the conventional method (5) is obtained by dissolving a heavy oil such as asphalt in the medium oil. In the solid-liquid separation, only the heavy oil in the medium oil is selectively porous carbon. Such a small amount (5% by weight or less) of heavy oil effectively suppresses spontaneous ignition of the porous coal.
[0014]
This conventional method {circle around (5)} is also a technique of covering the surface of the porous coal with oil to prevent contact with air, as in the above conventional method {circle around (4)}. The heavy oil component is particularly selectively adsorbed to active sites having high oxidation reactivity, and therefore, a high coating efficiency can be increased even with a small amount of oil component. In addition, in the conventional method (5), the moisture vapor evaporated and separated from the porous coal is compressed and heated to be a heating source in the dehydration step, and this is a highly efficient production method in that latent heat is recovered and used. Yes.
[0015]
On the other hand, from the viewpoint of a method of treating coal in a slurry state, (a) contacting the pulverized coal with medium oil and mixing it while applying a shearing force by stirring it to obtain a uniform slurry And (b) a method in which coarsely pulverized coal is first brought into contact with a medium oil, and after mixing into a mixture by stirring or the like, the coal is further finely pulverized by a ball mill or the like to obtain a uniform slurry, etc. Is adopted.
[0016]
In the case of the conventional method (5), the slurry state is also prepared by charging the pulverized porous charcoal and medium oil into a tank and mixing them with stirring to prepare a slurry.
[0017]
[Problems to be solved by the invention]
In the conventional method (5), as described above, after obtaining a mixed slurry of dehydrated porous charcoal and medium oil, finally solid-liquid separation is performed to remove the medium oil from the slurry to obtain a solid fuel. As the solid-liquid separation method, a medium oil removal method such as centrifugation or heating is performed. In such solid-liquid separation, it is more advantageous in terms of equipment and use energy to remove the medium oil from the high-concentration slurry and obtain the solid fuel than to remove the medium oil from the low-concentration slurry. Therefore, development of a method for obtaining a high-concentration slurry with high efficiency is desired.
[0018]
However, in the above conventional method (5), the proportion of moisture in the volume of the high water content porous coal is high. For example, in the case of lignite containing 65 wt% of moisture, about 72 vol% of water is contained. When mixing the raw material slurry of the raw material porous charcoal and the medium oil, it was difficult to prepare a high concentration slurry, and it was necessary to prepare the raw material slurry using a considerably large amount of the medium oil . For this reason, the slurry after dehydration was also obtained as a low concentration slurry having a large amount of medium oil.
[0019]
When a large amount of medium oil is used in this way, as described above, not only a large amount of energy is required for solid-liquid separation, but also when heating the raw slurry and dehydrating porous charcoal, A large amount of heat is consumed, leading to a decrease in thermal efficiency, and there is a problem that porous coal is separated in the slurry and the slurry is likely to be non-uniform.
[0020]
In addition, the conventional method {circle around (5)} employs a method in which the raw material is slurried and then heated, so it is necessary to perform indirect heating with a heat exchanger or the like. There is a problem in handling such that the slurry in the exchanger is likely to be non-uniform. There is also a problem that the facilities become complicated.
[0021]
The present invention has been made in view of the problems as described above, and aims to finally obtain a solid fuel having a good storability and transportability by using a porous coal as a raw material and suppressing spontaneous ignition. More specifically, it is an object of the present invention to provide a method capable of producing a high-concentration porous coal slurry with high thermal efficiency and simplifying the production equipment for the high-concentration porous coal slurry. .
[0022]
[Means for Solving the Problems]
The method for producing a high-concentration porous coal slurry according to the present invention, while maintaining the medium oil at a temperature not lower than the boiling point of water and not higher than its initial boiling point, is charged with the porous charcoal in the medium oil, The gist is to separate the portion of the high-concentration slurry by settling the charcoal.
[0023]
In the method of the present invention, dehydration is performed by introducing the porous charcoal into the heated medium oil without using the porous charcoal as a mixed slurry with the medium oil. The heating temperature of the medium oil is not less than the boiling point of water and not more than the initial boiling point of the medium oil as described above. The reason why the heating temperature of the medium oil is not less than the boiling point of water is that the water in the porous coal can be evaporated to the boiling point. The reason for setting it below the initial boiling point of the medium oil is to prevent the medium oil itself from evaporating.
[0024]
When porous charcoal is added to the medium oil maintained at such a temperature, the water contained in the porous charcoal boils, so the particles of the porous charcoal move vigorously in the medium oil, and heat is generated. It is efficiently transferred from the medium oil to the porous charcoal, and the contained water evaporates one after another, and dehydration proceeds.
[0025]
In this way, the porous coal from which most of the water has been removed by evaporative separation eliminates the phenomenon of water boiling, so that the movement becomes slow and settles downward. In this way, where the porous coal settles and accumulates, a high-concentration slurry of porous coal and medium oil is obtained, and a high-concentration slurry can be obtained by collecting the sedimented and deposited portion.
Then, if the medium oil contained in the said high concentration slurry is collect | recovered, the solid fuel by which spontaneous ignition property was suppressed can be obtained.
[0026]
As the medium oil, one showing an initial boiling point higher by 10 ° C. or more than the boiling point of water is preferable. In the case of a medium oil having a low initial boiling point, the medium oil evaporates simultaneously with the boiling of moisture, and the lower the initial boiling point, the greater the amount of evaporation of the medium oil. Accordingly, it is preferable that the initial boiling point is high, and those having the above initial boiling point are preferable. More preferably, the initial boiling point is 30 ° C. or more higher than the boiling point of water.
[0027]
Even if the initial boiling point of the medium oil as a whole shows a low value, it can be used as long as it contains a component having a boiling point higher than the boiling point of moisture, but the low boiling point component evaporates. Thereby, the thermal efficiency of the whole manufacturing apparatus falls.
[0028]
Further, the medium oil preferably has a density at 20 ° C. of 1.1 or less. When the dehydration is completed and the porous coal settles in the medium oil, the porous charcoal must have a higher density than the medium oil. Since the true density of the porous coal is generally around 1.4, it is preferable to use a medium oil having a density at 20 ° C. of 1.1 or less as described above in order to settle it well. More preferably, the medium oil has a density at 20 ° C. of 1.0 or less. As the medium oil, petroleum hydrocarbon oil is recommended.
[0029]
More preferably, the medium oil is a hydrocarbon oil containing 10% by weight or less of heavy oil. Examples of the heavy oil include coal-based heavy oil such as petroleum asphalt and coal tar, petroleum-based distillation residue, coal-based distillation residue, and the like. As the medium oil, these heavy oils are mixed with other hydrocarbon oils. Or a hydrocarbon oil originally containing these heavy oil components.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
<First example>
FIG. 1 is a conceptual diagram showing an example of an apparatus for carrying out the method for producing a high-concentration porous coal slurry according to the present invention.
The container 1 has a structure in which an upper cylinder 11 and a lower cylinder 12 having a smaller diameter are connected by an upper cone portion 13 having an inclination. An inclined lower cone part 14 is also connected to the bottom of the lower cylinder 12, and the concentrated solids are collected by collecting and depositing precipitated solids by the lower cone part 14. A slurry outlet 16 is connected to the bottom. A pipe 15 for heating the medium oil is passed through the upper cylinder 11.
[0031]
As a production method, first, porous charcoal pulverized to 5 mm or less is put into a container 1 containing a hydrocarbon oil (medium oil) heated to a temperature higher than the boiling point of water. The heating temperature of the medium oil is a temperature not lower than the boiling point of water and not higher than the initial boiling point of the medium oil, preferably not lower than 10 ° C. above the boiling point of water and not higher than the initial boiling point of the medium oil. More preferably, the temperature is 30 ° C. or higher than the boiling point of water and lower than the initial boiling point of the medium oil. When dehydration is performed at 400 kPa (about 4 atm), for example, the boiling point of water is 143.5 ° C. In this case, it is preferable to heat the medium oil to 175 ° C.
[0032]
In order to increase the contact area with the medium oil, it is desirable to pulverize the porous charcoal in advance, and the size of the pulverized porous charcoal particles is preferably 5 mm or less, more preferably as described above. Is about 3 mm or less.
[0033]
At the liquid level of the medium oil in the upper cylinder 11, the porous charcoal in contact with the high-temperature oil is rapidly heated, and the contained water starts to boil and evaporate rapidly. Due to this boiling, the particles of the porous coal move irregularly and violently in the medium oil, and the medium oil is dispersed with stirring. As a result, the contact between the high-temperature medium oil and the porous coal is remarkably promoted, and high heat transfer is obtained, so that the boiling evaporation of moisture proceeds efficiently.
[0034]
As the evaporation of moisture progresses and the evaporation amount decreases over time in this way, the movement of the porous coal gradually slows down, and the porous coal having a higher density than the medium oil settles in the medium oil. To do.
The settling porous carbon particles gather in the lower cylinder 12 of the container 1 and are concentrated to form a high-concentration slurry.
The porous charcoal forming the high-concentration slurry is dehydrated porous charcoal in which water is almost evaporated, and is further consolidated by being deposited on the bottom of the lower cylinder 12.
[0035]
The consolidated dehydrated porous coal is extracted as a slurry from the extraction port 16 at the bottom of the container 1. In this way, a dehydrated high concentration porous coal slurry is obtained.
[0036]
Thereafter, the high-concentration porous charcoal slurry is sent to the medium oil recovery step 4 by the pump 2, where the medium oil is recovered, and the medium oil is again put into the container 1 for circulation. In addition, the medium oil is newly replenished as the amount of medium oil that is taken out with the product (porous coal) and becomes insufficient.
[0037]
In addition, when the medium oil is introduced into the container 1, it is desirable to introduce it so as to form a circulating flow near the liquid surface in the container 1. Porous charcoal tends to float to the liquid surface, and heat transfer to the porous charcoal that has floated to the liquid surface in this way is low. Push charcoal into the liquid. By forming a circulation flow in this way, moisture evaporation from the porous coal proceeds more efficiently.
On the other hand, the dehydrated porous charcoal from which most of the medium oil has been removed in the medium oil recovery process 4 becomes an excellent solid fuel with suppressed spontaneous ignition.
[0038]
In the apparatus shown in FIG. 1, water vapor generated from porous charcoal in the container 1 is introduced into a pipe 17 on the upper cylinder 11, is heated by compression by the compressor 3, and passes through the pipe 15 to generate medium oil. Used for heating. Next, the remaining amount of heat is used in the heat exchanger 18 for heating the medium oil that is replenished to the container 1, and the water vapor is discharged as water.
[0039]
When the amount of heat is insufficient only by heating in the heat exchanger 18, the medium oil is heated in the heat exchanger 19 with a heat medium such as high-temperature hot oil, and the amount of heat is supplemented in this manner, whereby the container 1 The temperature inside can be maintained at a desired temperature.
[0040]
<Second example>
FIG. 2 is a conceptual diagram showing another example of an apparatus for carrying out the method for producing a high-concentration porous coal slurry according to the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals to avoid redundant description.
[0041]
A blade portion 25 is provided in the upper cylinder 21 of the container 10 in parallel with the upper cone portion 13. Since the settled porous charcoal does not enter between the blade portion 25 and the upper cone portion 13, a clarified layer of only medium oil is formed here. A pipe 26 is connected to the clarified layer so that the medium oil containing no porous charcoal can be extracted.
[0042]
As in the first example, the porous charcoal charged into the heating medium oil is evaporated and dehydrated, settled and concentrated in the lower cylinder 12 to become a dehydrated high-concentration porous charcoal slurry, and is extracted from the extraction port 16. Is issued.
[0043]
The water vapor generated from the porous charcoal in the vessel 10 is introduced into the pipe 17 on the upper cylinder 21, heated by compression by the compressor 3, used for heating the medium oil in the heat exchanger 27, and It is also used for heating the medium oil in the heat exchanger 29 and then discharged.
[0044]
The medium oil recovered from the high-concentration dehydrated porous coal slurry in the medium oil recovery step 4 is added with a short amount of medium oil (or a specific component that is deficient from the medium oil) and heated in the heat exchanger 29. The Next, the medium oil extracted from the pipe 26 is added and further heated in the heat exchanger 27. When the temperature of the medium oil is low, it is heated by the heat medium in the heat exchanger 28, and thus the temperature in the container 10 is maintained at a desired temperature.
[0045]
In the second example described above, the flow rate of the circulating medium oil can be arbitrarily set by extracting the medium oil from the clarified layer. In order to increase the temperature in the container 10, it is necessary to increase the medium oil to be added. However, if the medium oil is very high, the medium oil evaporates, so there is a limit to the rising temperature. is there. However, when the amount of circulating medium oil can be arbitrarily set as in the second example, the temperature of the medium oil in the container 10 can be controlled by increasing the circulating medium oil. Further, by increasing the amount of circulating medium oil, it is possible to more effectively suppress the floating of the porous coal to the liquid surface. Thus, the temperature of the medium oil can be freely controlled, and it becomes easy to control the flow state of the porous charcoal and the medium oil in the upper part of the container 10.
[0046]
On the other hand, in the first example, the amount of the circulating medium oil is determined by the concentration of the slurry extracted from the extraction port 16 and the recovery rate of the medium oil in the medium oil recovery step 4. There is no freedom in quantity. Therefore, there are some restrictions on the temperature control in the container 1, and the control of the flow state of the upper part of the container 1 is also restricted.
[0047]
Further, in the first example, since the long pipe 15 is passed through the container 1, this interferes with the sedimentation of the porous charcoal, and the apparatus becomes complicated. On the other hand, in the second example, It is advantageous without any problems.
[0048]
On the other hand, in terms of thermal efficiency, heat is directly supplied by the pipe 15 in the first example, which is advantageous in terms of thermal efficiency. On the other hand, in the case of the second example, since a heat exchanger is used, it is slightly inferior in terms of heat recovery.
That is, the first example is advantageous in terms of heat efficiency, and the second example has advantages in that the device design is not complicated and the operation is easy.
[0049]
The apparatus used in the present invention is not limited to the first and second examples described above, and has a dehydrating part for bringing the raw water-containing porous charcoal and the medium oil into contact with each other at the top, and dewatering settled at the bottom. Any device may be used as long as it has a function of concentrating porous coal and discharging it as a slurry.
[0050]
The amount of medium oil required to handle the slurry after dehydration is quite small. This is because lignite shrinks during the dehydration process, and the medium oil does not enter the micropores from which moisture has been removed. For example, even if medium oil impregnated in lignite is included, it can be concentrated to dry coal / medium oil = about 50/50 (weight ratio). Moreover, excluding the medium oil impregnated in lignite among the above medium oils, the weight ratio of the medium oil and the dry coal that actually contributes to the flow shows the dry coal / medium oil = about 50/19. A high-concentration slurry can be obtained.
[0051]
On the other hand, when the slurry is made from the beginning as in the conventional method (5), a large amount of oil is required due to the presence of moisture in the porous coal. For example, raw brown coal (containing 65 wt% moisture) and heavy oil A When mixing (medium oil) to make a slurry, the ratio of the highest concentration is when raw lignite / A heavy oil = 60/40 (weight ratio) [dry coal / A heavy oil = 21/40] Yes, the concentration is about 54 vol%. The slurry at this concentration has a high viscosity, and it is difficult to achieve a higher concentration than this. Therefore, as in the conventional method (5), when the raw material is first slurried, it cannot be handled in the dehydration step above the above concentration.
[0052]
On the other hand, in the present invention, since the slurry is not used in the dehydration, the amount of the medium oil at the time of dehydration is small, and the slurry after dehydration that has settled can be made high in concentration as described above. The amount of medium oil used as a whole can be reduced. That is, in the case of the conventional method {circle around (5)} which is first slurried, it is necessary to use a large amount of medium oil as described above, but in the present invention, the amount of medium oil handled in the dehydration step and the recovery step is reduced. It can be greatly reduced.
[0053]
【Example】
<Example 1>
Morwell brown coal containing 65 wt% of water was pulverized to 1 mm or less. 100 parts of A heavy oil (medium oil) in the container was maintained at 130 ° C., and 10 parts of the pulverized Morwell lignite was added to the A heavy oil. After the water of the lignite boiled and evaporated and naturally settled at the bottom of the container, the lignite at the bottom was recovered in a slurry state. The time required for most of the lignite to settle was 5 to 10 minutes.
[0054]
The lignite concentration was measured for the recovered slurry. Further, the slurry was centrifuged at 400 G to remove the adhering medium oil, and the moisture and medium oil amount remaining in the lignite were determined.
[0055]
<Example 2>
In the same manner as in Example 1 above, Morwell lignite containing 65 wt% of water was pulverized to 1 mm or less. As the medium oil, 80 parts of A heavy oil dissolved in 20 parts of asphalt was used, and the medium oil was kept at 130 ° C. in a container. As in Example 1, the medium oil was mixed with 10 parts of the pulverized Morwell lignite. Was added, the water was boiled and evaporated, and the lignite that naturally settled at the bottom of the container was recovered in a slurry state.
About the collect | recovered slurry, the lignite density | concentration was measured similarly and the water | moisture content and medium oil amount which remain | survived in lignite were calculated | required.
[0056]
<Comparative Example 1>
100 parts of pulverized Morwell lignite (containing 65 wt% water) and 100 parts of A heavy oil are mixed to form a slurry, heated while stirring at normal pressure, and heated for about 3 hours until the slurry temperature reaches 110 ° C. Evaporated. After dehydration, the lignite concentration of the slurry was measured. Further, the slurry was centrifuged at 400 G, the adhering medium oil was removed to recover the lignite, and the amount of water and medium oil remaining in the lignite was determined.
[0057]
<Comparative example 2>
100 parts of pulverized Morwell lignite (containing 65 wt% water) and 100 parts of medium oil in which 20 parts of asphalt are dissolved in 80 parts of A heavy oil are mixed to form a slurry, and the water is evaporated in the same manner as in Comparative Example 1 above. The lignite concentration of the slurry was measured, and the amount of water and medium oil remaining in the recovered lignite was determined.
[0058]
<Comparative Example 3>
150 parts of pulverized Morwell lignite (containing 65 wt% water) and 100 parts of A heavy oil (medium oil) were mixed to form a slurry, and the moisture was evaporated and the lignite concentration of the slurry was measured in the same manner as in Comparative Example 1 above. In addition, the amount of water and medium oil remaining in the recovered lignite was determined. In the case of Comparative Example 3, the amount of medium oil was insufficient at room temperature during the water evaporation, and it was difficult to make a uniform slurry. However, a uniform slurry was prepared by heating to 60 ° C. did it.
[0059]
<Result>
The results of Examples 1 and 2 and Comparative Examples 1 to 3 are shown in Table 1 below. In addition, about the quantity of the water | moisture content and medium oil which remain | survive in dehydrated lignite, it shows with the weight (kg) per 100kg of dry lignite. The amount of the medium oil in the recovered slurry includes a medium oil component (residual medium oil) impregnated in lignite.
[0060]
[Table 1]

[0061]
As can be seen from Table 1, in Examples 1 and 2, high-concentration slurries were obtained compared to Comparative Examples 1 to 3 which were dehydrated in a slurry state. Note that Comparative Examples 1 to 3 can be further concentrated by performing stationary separation or the like.
[0062]
In addition, with respect to the degree of dehydration, Examples 1 and 2 were sufficiently dehydrated, and rather could be dehydrated better than Comparative Examples 1 to 3. As for the medium oil remaining in lignite, Examples 1 and 2 have less residual medium oil than Comparative Examples 1 to 3, and therefore Examples 1 and 2 can be dehydrated well while remaining medium oil. I understand that.
[0063]
【The invention's effect】
In the method for producing a high concentration porous coal slurry according to the present invention, the raw material porous coal can be efficiently dehydrated to obtain a high concentration porous coal / medium oil slurry. In addition, the total amount of medium oil used in this production method can be reduced, and therefore the equipment can be simplified, such as a reduction in the number of high-viscosity slurry pumps used, and the energy efficiency can be significantly improved. Can do.
[0064]
As described above, the dehydrated porous charcoal slurry is then dehydrated porous charcoal (solid fuel) by removing the surface medium oil, but in the case of a high concentration slurry, the medium oil can be removed with low energy and small size. Therefore, it is effective to obtain a highly concentrated porous coal slurry as in the present invention. Moreover, the dehydrated porous coal from which the medium oil has been removed is a good solid fuel with suppressed spontaneous ignition. If the medium oil contains heavy oil, removing the medium oil from the high-concentration slurry will leave only the heavy oil in the dehydrated porous coal. The dehydrated porous coal in which the oil is selectively left is also a good solid fuel with suppressed spontaneous ignition.
[0065]
Further, in the present invention, unlike the conventional method (5), since lignite is directly put into the medium oil kept at a high temperature, there is no heat loss, and the particles move vigorously when the water boils, and in addition, the circulating medium oil Therefore, there is no need for facilities such as stirring.
[0066]
Moreover, since the porous charcoal particles that have boiled down are automatically settled and concentrated, the conventional concentration / separation step can be omitted, and the equipment can be further simplified. Energy efficiency can be improved.
[0067]
In the present invention, since the temperature of the porous coal particles and the boiling of water occur rapidly, the amount of medium oil impregnated in the lignite after dehydration decreases, and therefore the amount of medium oil consumed can be reduced. it can. The medium oil impregnated in the porous charcoal is difficult to recover mechanically, and therefore most of it will be recovered by evaporation. This contributes to improving energy efficiency.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an example of an apparatus for carrying out a method for producing a high-concentration porous coal slurry according to the present invention.
FIG. 2 is a conceptual diagram showing another example of an apparatus for carrying out the method for producing a highly concentrated porous coal slurry according to the present invention.
[Explanation of symbols]
1,10 containers
2 Pump
3 Compressor
4 Medium oil recovery process
11, 21 Upper cylinder
12 Lower cylinder
13 Upper cone
14 Lower cone
15, 17, 26 Pipe
16 outlet
18, 19, 27, 28, 29 heat exchanger
25 feathers

Claims (4)

A high-concentration slurry in which porous coal is present in the medium oil in a state where the medium oil is maintained at a temperature not lower than the boiling point of water and not higher than its initial boiling point, and the porous coal is precipitated in the medium. A method for producing a high-concentration porous charcoal slurry characterized by separating parts. The method for producing a high-concentration porous coal slurry according to claim 1, wherein the medium oil exhibits an initial boiling point that is 10 ° C. or more higher than the boiling point of water. The method for producing a high-concentration porous coal slurry according to claim 1 or 2, wherein the medium oil is a hydrocarbon oil having a density of 1.1 or less at 20 ° C. The method for producing a high-concentration porous coal slurry according to any one of claims 1 to 3, wherein the medium oil is a hydrocarbon oil containing 10 wt% or less of heavy oil.

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