JPH042639B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for carbonizing oil siel, and more specifically, there is a moving grid, a wind box is fixed above and below the moving grid, and the wind box and the moving grid are connected to each other. In a method of carbonizing oil siel using a device (hereinafter referred to as a moving lattice type device) that is sealed with water and has a structure that prevents the gas inside the wind box from leaking outside, the heated gas temperature for carbonization is and/or a method of controlling the amount of heating gas for carbonization and/or the horizontal movement speed of a moving grid. (Prior Art) A method of carbonizing oil shale using a moving grate type device called a circular grate, a straight grate, etc. is widely known as a method of sintering and cooling iron ore using such a device. The basic method is to heat or cool the solid particles by flowing a gas almost perpendicularly through a bed of solid particles loaded on a moving grid and moving horizontally with the moving grid. In the carbonization method of oil shale using this moving grid type device, as mentioned above, the oil shale to be carbonized is loaded on the moving lattice, and the oil shale itself moves in a fixed bed form and undergoes the carbonization process.
Oil siere has the characteristic that it does not easily turn into powder during the processing process. As is well known, when oil sheer is subjected to carbonization treatment, it not only generates many cracks in the oil sheer, but also becomes brittle and easily shatters with the slightest impact, producing powder. For this purpose, for example, a device (hereinafter referred to as a moving layer) that forms a moving layer of crushed oil siel in a container in which the crushed oil siel is supplied from near the top and taken out from near the bottom, and circulates a gas through the moving bed. When oil sheer is subjected to carbonization using a dry distillation device (referred to as a type device), a large amount of oil sheer granules are produced due to impact and friction caused by contact between oil sheer particles as the oil sheer layer moves. When a large amount of oil sheer powder is generated in this way, the gas flow resistance within the oil sheer layer increases, which not only increases the blowing power, but also causes uneven flow of gas within the oil sheer layer. It becomes impossible to carry out sufficient carbonization of the oil, and the quality of the carbonized oil is reduced. For this reason, during the carbonization process of oil sheer, the generation of oil sheer powder is extremely small.
This is why it is regarded as an excellent method. A conventional method of carbonizing oil shale using a moving grid apparatus is described in U.S. Pat. No. 3,325,395,
4058905, Publication No. 4082645, etc., and Document-1 "Oil Shale Deta Book"; US Department of Commerce, National Technical Information Service, P.B.80
−125636 (US Department of Commerce,
Natonal Technical Information Service,
PB80-125636), it is introduced as a circular-great carbonization process. Generally, it is known that the quality of oil siel varies greatly depending on the production area, and even in the same production area depending on the location of the mine and the depth of excavation. In other words, oilsieres can be broadly divided into kerogen and mineral substances, but their contents and compositions are significantly different. As a result of heating carbonization, most of the kerogen is
It decomposes at 350-500℃ to produce siel oil and gas, while minerals such as Nahcolite and Davsonite are
It is known to decompose at relatively low temperatures of 90-400℃. Also, the moisture content generally varies significantly between 3 and 20.
It changes by about %. When raw oil shale, whose quality fluctuates in this way, is subjected to continuous carbonization using a moving lattice type device,
This will cause the following inconvenience. That is, the thermal decomposition of kerogen and mineral substances are both endothermic reactions, and require a considerable amount of heat during carbonization. For example, it has been reported that the heat of decomposition of nahcolite and dawsonite is as follows. Nacostone decomposition: NaHCO ₃ →1/2Na ₂ CO ₃ +1/2 H ₂ O +1/2CO ₂ -26.6 Kcal/mol Dawsonite decomposition: NaAl(OH) ₂ CO ₃ →1/2 Na ₂ CO ₃ +1/2Al ₂ O ₃ +H ₂ O + 1/2CO ₂ -33.8 Kcal/mol Similarly, since water evaporates under carbonization conditions, a considerable amount of heat is required as latent heat of vaporization. In the moving lattice type device, the heat required to raise the sensible heat of the oil sheer and the reaction heat required for the above thermal decomposition are supplied by the gas passing through the oil sheer crushed material layer, but at this time the gas temperature Conventionally, a method of operation has been adopted in which both the amount of gas and the amount of gas are kept constant. In this case, as the quality of the raw oil shale to be carbonized changes, the amount of heat required for the thermal decomposition of kerogen and minerals and the evaporation of water will also vary, as described above, so the temperature of the oil shale itself will rise. The temperature will fluctuate. Therefore, up to the temperature required for thermal decomposition of kerogen (approximately 500℃),
There is a concern that the Sière temperature will not be reached and the yield of Sière oil will decrease. Conventional movable grid equipment often handles raw materials with a smaller range of fluctuation in grade, especially from a thermal perspective, than oil shale, such as iron ore sintering and cooling, and the above-mentioned disadvantages are not as noticeable. Therefore, operating conditions such as gas temperature, gas amount, and moving speed of the moving grid are generally operated under set constant conditions, and special attention must be paid to the continuous control method during operation. There is a background in which there was little need for it. Therefore, even in the carbonization technology using a mobile grating device for oil sheer, which is an extension of the conventional technology, no special attention has been paid to the continuous control method that takes into account fluctuations in the raw material sheer.
Currently, almost no related control technology has been proposed. (Problems to be Solved by the Invention) In view of the above-mentioned circumstances, the present invention proposes a control method for an oil siel carbonization apparatus that always maintains the maximum oil yield despite fluctuations in the raw oil sire. (Means for Solving the Problems) The present invention provides a method for heating and carbonizing the oil sier layer by exposing it to a hot gas flow flowing vertically through the oil sier layer while horizontally moving the oil sierre crushed material loaded on a moving grid. In the oil siere carbonization method,
Continuously measure the concentration of hydrocarbons contained in the gas that has passed through the portion of the oil sier layer that has reached a temperature equal to or higher than the carbonization temperature, and adjust the heating gas temperature and/or heating gas flow rate so that the hydrocarbon concentration is below a predetermined concentration. /or by changing the horizontal movement speed of the moving grid. The present inventors have developed the present invention by paying attention to the fact that siel oil and hydrocarbon gas produced during heating carbonization of oil siel are generated under substantially the same temperature conditions. When you heat the oil siere,
Thermal decomposition begins at around 350°C, the rate of oil production is high even at around 430°C, and the reaction is almost complete at 500°C. At the same time, in almost the same temperature range,
It is known to produce hydrogen (H ₂ ) and hydrocarbon gases such as methane (CH ₄ ), ethane (C ₂ H ₆ ), and propane (C ₃ H ₈ ). For example, Figures 4 and 5 are shown in Reference 2 [In SITU, 4(1),
1-37 (1980)]. On the other hand, hydrocarbon concentration can be continuously measured using a commonly used device equipped with a hydrogen flame ionization detector. Continuously measuring the amount of sierre oil produced by carbonization is extremely difficult, and no equipment has been developed yet, but hydrocarbon concentration can be measured continuously with great ease. The oil sierre crushed material loaded on the moving grid is heated and generates oil and gas, and while carbonization continues, hydrocarbons will be present in the gas that has passed through the oil sier layer, but eventually the carbonization will stop. Once completed, the generation of hydrocarbons and oil will cease and there will be almost no hydrocarbons present in the gas that has passed through the oilsier layer. During a series of operations, for example, if the content of water and minerals to be thermally decomposed increases, that is, if a large amount of heat is required for carbonization, the temperature of the oil siere will be raised sufficiently when the carbonization conditions are kept constant. However, by applying the present invention, it is possible to increase the gas temperature, increase the gas flow rate, and/or decrease the horizontal movement speed. Since carbonization conditions such as reduction can be quickly changed, a sufficient temperature rise of the oil siere can be ensured, and the oil yield can always be maintained at its maximum. On the other hand, when processing shale, which requires a small amount of heat for carbonization, lowering the gas temperature and/or gas flow rate and/or increasing the horizontal movement speed will avoid unnecessary temperature rises in the oil shale. It is possible to prevent this from happening. In other words, it is possible to always carbonize raw oil shale under optimal operating conditions despite fluctuations in quality, and as a result, the utility per unit of oil shale throughput can be minimized, which is extremely effective for energy-saving operation. be. Next, in order to clarify embodiments of the present invention, a description will be given based on the drawings. The system diagram shown in FIG. 1 is a case where the present invention is applied to a direct heating type moving grid carbonization process, in which the heating carbonization section W is divided by partition walls a and b, and the carbonization section is divided by partitions b and c. The combustion section X of the carbon remaining in the subsequent siere and the cooling section Y divided by the partition walls c and d are connected to the gas flow supplied to each section while the oil siere layer 2 loaded on the moving grid 1 moves. After exposure, carbonization, combustion, and cooling are performed sequentially. That is, in FIG. 1, on the left side of the heated carbonization zone W, crushed oil siel is loaded onto a moving grid 1 using an oil siel supply device (not shown) to form an oil siel layer 2. As the moving grid 1 moves, the oil siere layer 2 first enters the heating carbonization section W, where it burns a part of the carbonization product gas contained in the circulating gas and is exposed to the resulting hot gas flow. After being heated and carbonized, it moves to combustion zone X. The gas that has flown out of the heating carbonization section W is separated from the carbonization product oil and carbonization product water that flow out together with the gas in a gas-liquid separator S, and then is sucked into the blower 3 and a portion is taken out as product gas. The other part is first supplied to the heat exchanger H as a circulating gas. In the heat exchanger H, heat is exchanged with the hot gas that has flown out of the combustion zone X, and after the circulating gas is heated, it is circulated to the heating carbonization zone W again. The gas that has flowed out of the combustion zone X is discharged to the outside of the system by the blower 4. A part of the circulating gas is burned in a burner B installed at the gas side inlet of the heating section W to become hot gas and used for carbonization. In addition, air is supplied to the cooling section Y, and after being heated by exchanging heat with the waste sierre, it is supplied by the blower 5, some of it is supplied to the combustion section X through line g, and some is supplied to the heating carbonization section W through line h. They are used for combustion of residual carbon and for combustion of circulating gas, respectively, and the remainder is discharged outside the system. On the other hand, the produced oil and water separated by the gas-liquid separator S are separated into oil and water by the oil-water separator E, and then taken out of the system. The method for controlling the carbonization conditions in the heating carbonization section W is as follows. Right end of heating carbonization section W,
In other words, this is the area where the oil sier layer is exposed to the hot gas flow, and the temperature rises above the carbonization temperature, completing the carbonization reaction.The sampling tube i of the hydrocarbon concentration meter AN is placed at the position where the gas flowing through this area passes. Install. The hydrocarbon concentration in the gas passing through this position is continuously measured by the sampling tube i using the hydrocarbon concentration meter AN, and this measured value is input to the controller XC through the line j. The hydrocarbon concentration is set in advance in the controller XC, and depending on the difference between the measured value of the hydrocarbon concentration and this set value, a signal is sent through line k to operate the control valve V1 in a direction to reduce this difference. In other words, suppose the carbon concentration of controller XC is set to 2%.
In this case, if the measured value sent from line j is 5%, a signal is sent from the line according to the difference +3%, and control valve V1 is opened. When the control valve V1 is opened, more combustion air is sent to the burner B, thus increasing the combustion amount, increasing the temperature of the carbonization gas, increasing the carbonization rate of oil siel, and ensuring sufficient carbonization. It is a condition that it will be carried out. In Figure 1, F is raw oil shale, D is waste shale, A is air, AH
indicates hot air discharged outside the system, FF indicates exhaust gas flowing out of residual carbon combustion section X, φ indicates carbonized oil, and W indicates carbonized water. FIG. 2 shows a case where the gas flow rate is controlled instead of the carbonization gas temperature control in FIG. 1. According to the difference between the set value and the measured value from the controller XC, a signal is sent from the line 1 to the control valve V2, and the control valve V2 is operated.
That is, if the measured value is higher than the hydrocarbon concentration set value, the control valve V2 is opened by the above control method, the amount of gas flowing through the heated carbonization section W is increased, the carbonization rate is increased, and more sufficient carbonization is performed. It will be. In this case, a temperature detector is installed to keep the gas temperature at the inlet of heating carbonization section W constant.
Adjusted by AT, temperature controller TC, and air flow control valve V1. FIG. 3 shows a case where the moving speed of the grate is controlled. In this method, a signal is sent to the grate drive motor M from the line P according to the difference between the set value and the measured value from the controller XC, and its rotation speed is controlled. That is, when the measured total hydrocarbon concentration value is higher than the set value, the grate moving speed is controlled to decrease. Note that the same symbols in FIGS. 2 and 3 indicate the same devices or lines as in FIG. 1. In addition, as shown in Figures 1, 2, and 3, it is possible to control not only the hot gas temperature for carbonization, gas flow rate, and grate movement speed independently, but also to simultaneously control two or more of these conditions. It is also possible to do this. Next, the effects of the present invention will be explained using examples. Example 1 Crushed oil siere was placed in a container with a diameter of 500 mm.
After filling to a height of 1000 mm, gas heated to 700°C was passed through the tank, and the total hydrocarbon concentration in the outlet gas was measured using a measuring device equipped with a hydrogen flame ionization detector. In addition, water was sprayed onto the outlet gas, and after cooling, oil was collected and the amount thereof was measured, and the results shown in Table 1 were obtained.

[Table] Hydrocarbon concentrations are methane equivalent values. This example shows that there is a correlation between the total hydrocarbon concentration and the oil yield, and under carbonization conditions where the total hydrocarbon concentration is high, the carbonization is not completed and the oil yield is low. Example 2 When 3 tons of oil siel was continuously treated using the oil siel carbonization apparatus of the embodiment shown in FIG. 3, the following results were obtained. Siel oil yield 228 Average carbonization time 20mm Comparative example 3 tons of oil Siel from the same mining area as Example 2,
Continuous carbonization was performed without controlling the grate movement speed, and the following results were obtained. Siel oil yield 195 However, the grate moving speed was kept constant so that the average carbonization time was 20 mm. Further, the carbonization gas concentration and gas flow rate were the same as in Example 2. From Example 2 and Comparative Example, it was confirmed that the method of controlling carbonization conditions according to the present invention was effective in increasing the oil yield. (Effects of the invention) The present invention continuously measures the concentration of hydrocarbons contained in the gas that has passed through the oil sier layer that has reached the carbonization temperature (350°C) or higher, and when the hydrocarbon concentration is below a predetermined concentration, that is, the carbonization is completed. Since the heating gas temperature and/or the heating gas flow rate and/or the horizontal movement speed of the moving grid are controlled in this way, the following remarkable effects are produced. (1) The oil yield can always be maintained at the maximum despite fluctuations in the raw material oil shale. (2) Utility per unit of oil siel throughput can be minimized.

[Brief explanation of drawings]

Figures 1, 2, and 3 are explanatory diagrams showing embodiments of the present invention. Figures 4 and 5 are temperature and hydrocarbon generation rate when oil shale is carbonized, and temperature and oil generation rate. It is a graph showing the correlation. 1: Moving grid, 2: Oil siere layer, 3: Blower, W: Heating carbonization section, X: Combustion section, Y:
Cooling section, AN: Hydrocarbon concentration meter, AT: Temperature detector, M: Grate drive motor.

Claims (1)

[Claims] 1. In an oil sier carbonization method in which the oil sierre crushed material loaded on a moving grid is horizontally moved, the oil sierre layer is exposed to a hot gas flow flowing in the vertical direction, and the oil sierre layer is heated and carbonized. The concentration of hydrocarbons contained in the gas that has passed through the part that has reached the carbonization temperature or higher is continuously measured, and the heating gas temperature and/or heating gas flow rate and/or moving grid are adjusted so that the hydrocarbon concentration is below a predetermined concentration. A method of controlling an oil siel carbonization apparatus, characterized by changing the horizontal movement speed of the oil siere carbonization apparatus.