JPS63139979A - Method of controlling oil shale dry distillation device - Google Patents

Abstract

PURPOSE:To enable the yield of oil shale to be kept at is maximum, by continuously measuring the concn. of hydrocarbon in gas which has passed through layers at a temp. not lower than a dry distillation temp. in oil shale layers and controlling operation conditions by using the measured valves in dry distilling oil shale by using a translation lattice device. CONSTITUTION:While crushed oil shale F placed on a translating lattice, is horizontally conveyed, an oil shale layer 2 is exposed to a hot gas stream (formed by burning part of recycling gas with a burner B) flowing in the vertical directions to dry-distill oil shale. The concn. of hydrocarbon in gas (sampling tube i) which has passed through layers at a temp. not lower than the dry distillation temp. (350 deg.C) in the oil shale layer 2 is continuously measured. The temp. of heating gas an/or the flow rate of heating gas and/or the horizontal move rate of the translation lattice are/is changed so as to adjust the concn. of the hydrocarbon to a predetermined concn. or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for carbonizing oil shale, and more specifically, the present invention relates to a method for carbonizing oil shale. A method of carbonizing oil shale using a device (hereinafter referred to as a moving grid type device) in which the space between the wind box and the moving grid is sealed with water so that the gas inside the wind box does not leak outside. The present invention relates to a method of controlling the temperature of heating gas for carbonization, the amount of heating gas for carbonization, and/or the horizontal movement speed of a moving grid.

(Prior art) A method for carbonizing oil shale using a moving lattice type device called a circular grate, a straight grate, etc. is widely known as a method for burning and cooling iron ore using such a device, and the body is fixed. Because oil shale is carbonized while moving in layers, it is less likely to turn into powder during the treatment process.

It has the property of becoming brittle and easily crushed by 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 oil shale crushed material in a container in which the oil shale crushed material is supplied from near the top and taken out from near the bottom, and allows a gas body to flow through the moving bed. When oil shale is subjected to carbonization treatment using a dry-distillation device (referred to as a type device), a large amount of oil shale particles are generated due to impact and friction caused by contact between oil shale particles as the oil shale layer moves.

As described above, a large amount of oil shale powder deteriorates the quality of the oil produced by carbonization. For this reason, it has been proposed that the generation of oil shale powder during the oil shale carbonization process is caused by extremely few moving grids, and the literature
11 Oilsier Data Book (Oil 5h
ale Data Book) ; Uest Heartment Op Commerce, National Technical Information Service, P80-
125636 (U, SDDepartment of
Commerce, Natonal Techn.
icalInformation 5service,
PB 80-125636) J as a circular-great carbonization process.

It is generally known that the quality of oil shale varies greatly depending on the production area, and even in the same production area depending on the mine location and excavation depth. In other words, oil shale can be broadly divided into kerogone and mineral substances, but their contents and compositions are significantly different.

Due to heating carbonization, most of the kerogen is 350 ~
It decomposes at 500°C and changes from 3 to 20% in sierre oil and gari.

When raw oil shale whose quality fluctuates as described above is subjected to continuous carbonization treatment using a moving grid type device, the following disadvantages occur. That is, the thermal decomposition of the above-mentioned kerogne 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 doutunite is as follows.

Nacostone decomposition: N, HCO3→-Na2 CO3+
-H2O+ -co! -26,6) fj/mo1 decomposition: Nau(OH)2 Cas→HHat
CO3" HA1203+ H20+ HCO2-3
3,81,7/mol and water similarly evaporate under carbonization conditions, so a considerable amount of heat is required as latent heat of vaporization.

In the moving lattice type device, the heat required to increase the sensible heat of oil shale and the reaction heat required for the above-mentioned thermal decomposition are absorbed by the gas passing through the oil shale crushed material layer as the feed quality changes, as described above. Since the amount of heat required for thermal decomposition of silogen and minerals and evaporation of water varies, the temperature reached by the oil shale itself varies. For this reason, there is a concern that the Sierre temperature will not reach the temperature required for thermal decomposition of kerogen (approximately 500° C.), resulting in a decrease in the yield of Sierre oil.

Conventional moving grid type equipment often handles raw materials with a smaller range of fluctuation in grade, especially from a thermal perspective, compared to iron ore sintering and cooling ring oil shale, and the above-mentioned disadvantages are not as noticeable. Therefore, it is common practice to operate under fixed operating conditions such as gas temperature, gas amount, and moving speed of the moving grid, 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 carbonization technology using a mobile lattice device for oil shale, 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 shale, and related... In view of the above-mentioned circumstances, the present invention proposes a control method for an oil shale carbonization apparatus that always maintains the maximum oil yield despite fluctuations in the raw oil shale.

(Means for Solving the Problems) The present invention provides a method for heating and carbonizing the oil shale layer by exposing it to a hot gas flow flowing vertically through the oil shale layer while horizontally moving the oil shale crushed material loaded on a moving grid. In the oil shale carbonization method, among the oil shale layers,
Continuously measure the concentration of hydrocarbons contained in the gas that has passed through the part that has reached the carbonization temperature, and adjust the heating gas temperature and/or heating gas flow rate and/or horizontal movement of the moving grid to keep the hydrocarbon concentration below a predetermined concentration. It is to change the speed.

The present inventors have developed the present invention by paying attention to the fact that sierre oil and hydrocarbon gas produced during oil fail heating carbonization are generated under substantially the same temperature conditions. When oil shale is heated, thermal decomposition starts at around 350°C, and even at around 430°C, the oil production rate is high,
It is known that at 0°C, the temperature is almost 1. For example, Figures 4 and 5
a, ゛, literature z C in stew IN 5ITU+
4(1), p. 1 The hydrocarbon concentration can be determined by commonly used water determination. 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 shale 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 shale layer, but eventually the carbonization will stop. When photons are released, the generation of hydrocarbons and oil stops, and almost no hydrocarbons exist in the gas that has passed through the oil shale layer.

During a series of operations, for example, if the content of water and mineral substances that are thermally decomposed increases, that is, if a large amount of heat is required for carbonization, the temperature of the oil shale will be raised sufficiently when the carbonization conditions are kept constant. Sufficient heating temperature can be ensured,
The oil yield can always be kept at a maximum.

Conversely, when processing shale, which requires less heat for carbonization, lowering the gas temperature and/or gas flow rate, and/or increasing the horizontal movement speed, etc., will prevent the oil shale from heating up unnecessarily. It is possible to prevent this from happening. In other words, raw oil shale can always be carbonized under optimal operating conditions despite fluctuations in quality, and as a result, the utility per unit of oil shale processing can be minimized, which is extremely effective for energy-saving operation. be.

Next, in order to clarify the embodiments of the present invention, description will be made with reference to 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 zone W is divided by partition walls a and b, and the carbonization zone is divided by partition wall C. Combustion section X of carbon remaining in the subsequent fail, partition wall C
The oil shale layer 2 loaded on the moving grid 1 moves through the cooling sections Y divided by After being heated and carbonized by burning a part of the resulting carbonized gas, the combustion section
Move to.

The gas that has flowed out of the heating carbonization zone W is separated from the carbonization product oil and carbonization product water that flow out together with the gas in the gas-liquid separator S, and then is sucked into the blower 3, where a part of it is used 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 flowing out of the combustion section X is discharged to the outside of the yarn by the blower 4. A part of the circulating gas is combusted in a burner B installed at the gas side inlet of the heating section W, and becomes hot gas, which is used for carbonization. Also, air is supplied to the cooling section Y,
It is discharged to the outside of the heat exchange system along with the waste sierre.

The method for controlling the carbonization conditions in the heating carbonization section W is as follows. The right end of the heating carbonization section W, that is, the area where the oil shale layer is exposed to the hot gas flow and reaches a temperature higher than the carbonization temperature to complete the carbonization reaction, has a hydrocarbon concentration at the position where the gas passing through this area passes. Install sampling tube 1 of total AN. Using the sampling tube 1, the hydrocarbon concentration in the gas passing through this position is continuously measured by hydrocarbon concentration meters A and N, and this measured value is input to the controller XC through line J.

Set the hydrocarbon concentration on the controller XC in advance,
Depending on the difference between the measured hydrocarbon concentration value and this set value, a signal is sent through line k to operate the control pulp v1 in a direction to reduce this difference.

In other words, if the carbon concentration of controller is the exhaust gas flowing out of the 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 line 1 to control pulp v2, and control pulp V
Operate 2i. That is, if the measured value is higher than the hydrocarbon concentration set value, the control pulp v2 is opened by the above control method, the amount of gas flowing through the heated carbonization section W increases, the carbonization rate increases, and more sufficient carbonization is performed. It will be. In this case, a signal is sent to the temperature detector AT, temperature controller TC, and air flow rate control pulp motor M so that the gas temperature at the inlet of the heating carbonization section W is kept constant.
This is a method of controlling the rotation speed. That is, it is possible not only to use the total hydrocarbon concentration measurement value to independently control the set amount and the grate moving speed, but also to simultaneously control two or more of these conditions.

Next, the effects of the present invention will be explained using examples.

Example 1 Crushed oil shale was crushed with a diameter of 500 mm. in a container of 100
After filling to a height of 0.0°C, 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 1 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 shale was continuously processed using the oil shale carbonization apparatus of the embodiment shown in FIG. 3, the following results were obtained.

Ciel oil yield 228 Average carbonization time 2o.

Comparative Example When 3 tons of oil shale from the same mining area as Example 2 was continuously carbonized without controlling the grate movement speed, the following results were obtained.

7 Ale oil yield: 195 However, the grate movement speed was kept constant so that the average carbonization time was 20 fins. The carbonization gas concentration and gas flow were also determined.

“(Effect of the invention) The hydrogen concentration is continuously measured, and when the hydrocarbon concentration is below a predetermined concentration,
That is, since the heating gas temperature and/or the heating gas flow rate and/or the horizontal movement speed of the moving grid are controlled so that the carbonization is completed, the following remarkable effects are produced. (1
) The oil yield can always be maintained at the maximum despite fluctuations in the raw oil shale. (2) Utility per unit oil shale throughput can be minimized.

[Brief explanation of the drawing]

Figures 1, 2, and 5 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 shale layer 5 = blower
W: Heating carbonization section X: Combustion section Y:
To the cooling section N: Hydrocarbon concentration meter AT: Temperature change detector

Claims (1)

[Claims] In an oil shale carbonization method in which oil shale crushed material loaded on a moving grid is horizontally moved, the oil shale layer is exposed to a hot gas flow flowing in the vertical direction, and 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 the heating gas flow rate and/or the moving grid are adjusted so that the hydrocarbon concentration is below a predetermined concentration. A method of controlling an oil shale carbonization device characterized by changing the horizontal movement speed.