JPS6014069B2 - Method for turning oil sludge into fuel - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for converting oil mud consisting of oil, water, and solids into fuel, and in particular, it is an object of the present invention to provide a method suitable for producing fuel of good quality even when the composition ratio of oil, water, and solids varies greatly. It is something to do. Oil sludge is made up of oil, water, and solid matter, and is found at the bottom of crude oil tanks.
It occurs on the bottom of tankers or in the manufacturing process of petrochemical products. Because all of these oil sludges contain large amounts of oil, it is prohibited to bury them in landfills or dump them into the ocean, and they are often incinerated.
Incineration of oil sludge as it is not only wastes valuable resources, but also damages the furnace because it contains a large amount of oil and increases the amount of exhaust gas treatment. Furthermore, considering the increase in the amount of oil sludge generated in the future, there will be many problems with simple incineration treatment in the future. Although this kind of oil mud can essentially be reused as fuel oil by itself or by mixing it with other fuel oils, the reason behind its reuse is that the conventional methods are as follows: This is because there were some shortcomings. '1} The properties of oil mud (
Because the composition (composition) varies widely, the quality of the final fuel oil obtained is inconsistent and difficult to use. (Refer to the section on supply oil mud in Table 1) Table 1 '2) In order to maintain constant quality, the crusher, classifier, or dehydrator must all be designed with a large margin. The cost is high. The economic advantage of using oil sludge as fuel oil disappears. The present inventors have conducted intensive research to provide a method for economically producing fuel oil with less variation in quality even for oil mud, which has a large change in properties. is the crushing process and the dehydration process, ■ The reason for this is that ``As mentioned above, the solids load in the crusher fluctuates due to large changes in the solids concentration in the oil mud.'' Therefore, the crusher and classifier It was not possible to set the design conditions to the highest value of solids loading;
■ Also, the water in oil mud is often very fine.
I learned that thermal static dehydration required a lot of static time and a large static tank, and found that the following method was very effective as a method to solve the above problems. . '1- Oil mud, which has rarely been reused in the past, can be roughly summarized through solid-liquid separation, pulverization of solids, classification of pulverized materials,
Dehydration of separated liquid (recovery of separated oil) “Separated oil or fuel oil (
By combining methods such as mixing C heavy oil) with solids, it is possible to obtain an oil mud fuel that can be economically reused as fuel. (Refer to the explanation of the flow in Figure 1 below) ■ In the case of crushing solid materials, there are appropriate conditions to reduce the required power for crushing and to make the crusher small. ~7% by weight (particularly preferably from 30 to 5% by weight)
) can be kept constant at an appropriate content, the grinding efficiency will be significantly improved. If the solid content is less than 2% by weight, it is not preferable because the chances of contact between the solids and between the solids and the grinding medium (for example, a pole) are reduced. If it exceeds a wide weight percentage, the apparent viscosity of the oil mud becomes too large and the movement of the grinding media is hindered, so it is not preferable. (See Figure 2. Figure 2 is a chart showing the relationship between solids content, weight %, and required power for crushing per unit weight of solids, where Q indicates a preferable range and 8 indicates a particularly preferable range. ) (31) With oil mud whose solids content varies widely, it was difficult to obtain oil mud with the solids content as pointed out in (2' above), but a horizontal type solid-liquid separator was installed before the crusher. A centrifugal separator is used to separate the separated product into a solid-based product (hereinafter referred to as separated solids) and a liquid-based separated product (hereinafter referred to as separated liquid), which is linked to an oil slurry supply device during the transfer process of the separated solids. By measuring the weight with a meter and adjusting the amount of oil slurry supplied accordingly, the amount of solids supplied to the crusher can be kept constant. (See explanation regarding Figure 3 below) Centrifugal separation has the synergistic effect of separating oil and water in the separated liquid and making the water droplets coarser. Therefore, if the trout is transported by gravity or by a pump with low shearing force and then heated and allowed to settle, the dewatering efficiency can be significantly improved. Furthermore, by constantly sucking the separated oil from the upper layer using a float-type suction device, it is possible to recover the separated oil with a small water content.(See the explanation regarding Figure 4 below.)
Since the amount of solids supplied at the inlet of the crusher is constant, if the separated oil obtained in [4] or other fuel oil is mixed, the solids content at the inlet of the crusher can be adjusted to an appropriate value. I can keep it. That is, [2} becomes possible. '61 Separated oil has been dehydrated, and the solids content is also constant due to t5}, so the composition of the crushed oil mud is constant. By classifying the pulverized solids using a '71 screen (silk type) classifier, the permeate side does not contain solids larger than the screen opening. Shelf According to {6}t■ above, it is possible to always produce oil mud fuel with stable properties. Moreover, due to the effects of ■ and '4}, the cost of crushing and dewatering can be significantly reduced, and low-cost oil mud fuel can be produced. The present invention has been completed based on the above knowledge, and is based on the following: ``After separating oil mud consisting of oil, water, and solids into a solid-based separated product and a liquid-based separated product using a solid-liquid separator, The liquid-based separated product is dehydrated and separated into separated oil and separated water, and the solid-based separated product is mixed and adjusted with separated oil or fuel oil, and then the solids contained are pulverized using a pulverizer. After the mechanical treatment, a classifier separates the dehydrated oil mud into a dehydrated oil mud containing many coarse particles and a dehydrated oil mud containing only fine particles. The gist of this invention is a method for converting oil mud into fuel, which is characterized in that the dehydrated oil mud is used as fuel (as it is) or mixed with fuel oil. The oil mud is stored under heated simulated mud conditions in an oil mud storage tank 1 equipped with a fly slurry machine 2 and a heater 3.As mentioned above (see Table 1), oil mud has a solid content depending on its type. Since the solid content is different, and the solids contained in the same oil mud have sedimentation properties, the solid content concentration distribution in the height direction within the storage tank 1 is different, and therefore the solid content varies considerably depending on the time when the oil mud is taken out. In order to make this change surprising, the Koji Azusa Machine 2 should be made powerful (many oil muds require a concentrated floating force of 0.0 W or more per oil mud), but this is not economical. This is also unfavorable in terms of the strength of the tank 1. In this way, the oil mud with different solid contents is passed through the oil mud supply pipe 4 by the oil mud supply pump 5, and is connected to the heater 7 in order to increase the separation effect. After being heated to a certain temperature in In the far-D separator, solids are discharged by a built-in screw (not shown), and solids are discharged from the solids discharge pipe i.
The solids are transferred through the solids conveyor 13 to the inlet hopper 14 of the crusher 16. This conveyor 13 is equipped with a weight scale 12 that can measure the amount of solids transferred, and the set weight (the amount of solids transferred)
In this case, a signal is sent from the signal circuit 1 to the flow control valve 6 to reduce the amount of oil sludge supplied. If the weight is less than the set weight, the amount of oil sludge supplied is increased. In this way, a fixed amount of solids is quantitatively supplied to the crusher 16 even for oil muds having different solids contents. On the other hand, the liquid discharged from the horizontal centrifuge 8 passes through the liquid discharge pipe 9 and is sent to the heating static tank 27 by gravity and the residual pressure of the oil mud supply pump 5 without going through the pump. This horizontal far-D separator 8 for separating Oka liquid does not have a mechanism to take out oil and water separately, but as mentioned above, in the far-D force field, most of the oil and water are separated, so heating A mechanism for re-emulsifying the oil and water separated during the transfer to the static tank 27 (
Centrifugal pumps, etc.) make direct heating and direct dehydration extremely easy. The heating stationary tank 27 is equipped with a heater 31 and a flow type suction device 28, and heating stationary dehydration is performed here, and a dehydration accelerator is added as necessary. The upper layer of separated oil with the highest dehydration rate is always collected by the float-type suction device 28, and is quantitatively fed to the mixer 15 of the crusher 16 through the separated oil transfer pump 301 and the separated oil transfer pipe 29. It is mixed with solids so that the content becomes a constant value of 20 to 7% by weight and sent to the crusher 16. At this time, in the case of oil sludge with a high solids content, since there is not enough separated oil to be recovered, the fuel oil is transferred from the tank 33 to the mixer 15 through the fuel oil transfer pipe 36 to the crusher by the pump 34. V is supplied. In addition, the separated water is separated from the separated water discharge pipe 3.
2, and sent to an oil/water treatment device (not shown) for treatment. The oil mud (hereinafter referred to as dehydrated oil mud) adjusted to a solid content of 20 to 7% by weight, preferably 30 to 5% by weight, suitable for solids and separated oil or fuel oil and crushing, is passed through a crusher 16. The contained solids are pulverized and sent to a classifier 19 through a pulverized material transfer pipe 17 by a pulverized material transfer pump 18. The classifier 19 has a certain opening (in most cases, 100 to 300)
It has a built-in screen 20 of micron grains, which allows oil mud containing solids of a certain particle size or less (hereinafter referred to as fine dehydrated oil mud) and oil mud containing solids of a certain number of fleas or more (hereinafter referred to as coarse grain dehydrated oil mud). ). The coarse dehydrated oil mud passes through the coarse dehydrated oil mud transfer pipe 21 via the circulation flow rate control valve 22, and is again sent to the crusher 16 where it is crushed. On the other hand, when the fine dehydrated oil mud is used as a fuel, unnecessary moisture and solids with large particle sizes that cause trouble have been crushed or removed, so the fine dehydrated oil mud is passed through the fine dehydrated oil mud transfer pipe 23 to the dehydrator 25. and is sent to an oil mud fuel storage tank 24 equipped with a heater 26. The properties of the oil mud fuel sent to and stored in the storage tank 24 are as shown in the column of oil mud fuel in Table 1, with extremely small amounts of moisture and solid matter, and the solid matter present is extremely fine. Therefore, it is suitable as a fuel. If high-calorie oil mud fuel is required from the combustion device (not shown), the fuel oil or separated oil is supplied to the mixer from the transfer pipe 35 or 37, mixed with the fine dehydrated oil mud, and then It may be sent to the storage tank 24. The configuration of the present invention has been described above using the flow of one specific example thereof, and the effects of the present invention will be described below. Figure 3 is a chart showing an example of adjusting the solids content at the inlet of the crusher (16 in the above flow) when the present invention is applied, and shows the solids content (wt%) versus the operating time (hr) and oil mud supply. It shows the relationship between quantity (me'hr). In the figure, curve [1] shows the change in the solids content in the supplied oil mud at the inlet of the centrifuge 8.As is clear from this, even though the solids content is the same, the solids content changes over time. It changes and becomes lower. The reason for this is, as mentioned above, that the solids in the oil mud have a higher specific gravity than oil or water, so they tend to settle, and the closer to the bottom of the oil mud storage tank 1, the higher the solid content. Therefore, when oil mud is drawn from the bottom of the tank 1, the solids content decreases as the operating time passes, as shown by curve [1]. If such oil sludge is put into the crusher 16 as it is, it is not preferable because the solid load amount changes greatly, but if the amount of oil sludge supplied (curve [V]) is determined according to the solids content as in the present invention, The solids content at the inlet of the crusher 16 becomes constant (curve [m]), allowing proper crushing operation. (See FIG. 2 for the appropriate value of the solids content to reduce the power required for crushing the solids.) FIG. 4 is a chart showing the relationship between the dewatering time and the dewatering rate. In the figure, curve [1] is an example of dehydration when applying the present invention (i.e., the case where the centrifuged liquid is placed in the heating tank 27 by gravity after being applied to the centrifugal separator 8), and the curve [B] is the centrifuged liquid. An example of dehydration when oil is transported by a centrifugal pump and then dehydrated (the oil coarsened by the centrifugal separator is slightly emulsified by the centrifugal pump). Example of dehydration (directly heated static tank 2 from oil mud supply pump 5)
7). Curve [1],

As is clear from [0] and [m], it can be seen that according to the present invention, a high dehydration rate can be obtained with a very short dehydration time. This is because, as mentioned above, most of the oil and water in the oil mud are separated during the centrifugation process, and this is dehydrated by static heating in the heated static tank 27 without being re-emulsified. It's for a reason. The oil mud fuel in the second half of Table 1 shows the results of the property analysis of the oil mud fuel carried out according to the present invention.According to the present invention, the quality is always constant regardless of changes in the properties of the supplied V oil mud. Furthermore, due to the high dehydration rate, there is little moisture in the oil mud fuel, and due to the proper crushing operation, it does not contain any solids with large particle sizes that can cause trouble during combustion. It will be understood that there is no. Brief Description of the Drawings Figure 1 shows the flow of one embodiment of the present invention, and Figure 2 shows the relationship between the solids content (wt%) in oil mud and the required power for crushing per unit weight of solids. diagrams,
FIG. 3 is a chart showing the relationship between solids content (wt%) and oil mud supply amount (in/hr) with respect to operating time, and FIG. 4 is a chart showing the relationship between dewatering time and dewatering rate. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. After separating oil mud consisting of oil, water, and solids into a solid-based separated product and a liquid-based separated product using a solid-liquid separator, the liquid-based separated product is dehydrated to form separated oil. Separated water and the above solids-based separated product are:
After adjusting the mixture with separated oil or fuel oil, the contained solids are pulverized using a crusher, and then separated into dehydrated oil mud containing many coarse particles and dehydrated oil mud containing only fine particles using a classifier. A method for converting oil mud into fuel, characterized in that the dehydrated oil mud containing a large amount of silt is crushed again by a crusher, and the dehydrated oil mud containing only fine particles is used as a fuel as it is or by mixing it with fuel oil.