JPS58176292A - Process and apparatus for recovering oil and gas from oil shale - Google Patents

Abstract

PURPOSE:To recover high-quality oil and gas with good thermal efficiency, by forming a layer of coarse oil shale on a moving grate, recovering oil and gas by dry distillation, and carrying it to a combustion step, in which heat held by the oil shale is recovered. CONSTITUTION:A layer 2 of crushed oil shale is formed on a moving grate 1, introduced into a preheating/dry distillation zone A and subjected to dry distillation supplying a non-oxidizing, high-temp. gas 19, and produced oil 8 and gas 11 are recovered. Then the oil shale layer 2 is supplied to a crusher C, crushed and introduced into a combustion column D, where the oil shale is burned by introducing a part 15 of an oxygen-contg., recovered gas stream, to recover heat. The residual solid particle is introduced into a cooling column E, into which a part of the recovered gas is introduced as a cooling gas 9, and the sensible heat held by the solid particle is recovered by transfer to the cooling gas 9. The gas heated to a high temp. and discharged from the cooling column E is recycled and used as the heating gas 19 for the preheating/dry distillation zone A.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recovering oil and gas from oil shale and to a configuration of equipment used to carry out the invention of this method. More specifically, there is a moving grid, and there are fixed wind boxes above and below the moving grid, and there is a water seal between the wind box and the moving grid, so that the gas inside the wind box does not leak out. After drying and carbonizing the oil shale in the moving grid equipment, the oil shale is crushed in a crushing section to reduce the particle size. The present invention relates to a method and apparatus for efficiently recovering oil from oil shale by efficiently recovering the amount of heat held by the oil shale within a plurality of sections forming a fluidized bed state after adjustment.

The object of the present invention is to provide a movable grid type device which eliminates the drawbacks of the prior art.
The purpose of the present invention is to provide a method for recovering oil from oil shale using a device that combines a crushing device and a fluidized bed device. (2) By reducing the solid particle size of oil shale, combustion in the fluidized bed combustion tower is facilitated;
(3) Improving the thermal efficiency of oil shale carbonization plants; (4) Utilizing low-grade heat such as waste heat of combustion exhaust gas, (5) Because gas containing oxygen such as combustion exhaust gas is not used in the carbonization section, high quality carbonization oil and carbonization gas can be produced; (6) Minimum required. (1) (2) (3) (a) (5)
)\ What the term can accomplish. In other words, the purpose is to provide an economical oil siel carbonization plant.

of oil shale using moving lattice equipment.

Regarding the carbonization method, please refer to Japanese Patent Application No. 56-90820.
Furthermore, a method and apparatus for carbonizing oil-bearing minerals using a fluidized bed have already been proposed in Japanese Patent Application No. 56-98402, but the present invention combines these methods to develop a technology for carbonizing oil shale more efficiently. This is a suggestion for improvement.

Oil shale has different thermal decomposition characteristics depending on its origin.

In addition, the amount of attached moisture and crystallized water also varies considerably depending on the production area (see Table 1).

In addition, even in the case of the same production area, 3 to 10
The adhering moisture content in wt, % changes (see Table 2). Therefore, when carbonizing oil shale with a low content of adhering water or crystallized water, it is necessary to
Oil can be efficiently recovered from oil shale by combining the technology proposed in No. 1, which is divided into a drying section and a carbonization section, into one section, and causing drying and carbonization to occur within the internuclear section.

The present invention relates to a technique that improves the invention proposed in Japanese Patent Application No. 116361/1982 and applies it to a method for recovering oil from oil shale containing low amounts of adhering water and crystallized water.

In the preheating/carbonization section, when the adhering moisture and crystal water evaporate, oil shale chunks form cracks, forming chunks with different diameters. Oil shale is carbonized,
Approximately half of the hydrocarbon compounds initially contained are released as carbonized oil and gas, but in the oil fail after carbonization, the active ingredients, mainly carbon, are about half of the content before carbonization. also remains. Therefore, as a method for recovering this effective carbonaceous material, as proposed in the previous Japanese Patent Application No. 56-98402, the carbonaceous material is recovered as thermal energy by burning the carbonaceous material with oxygen-containing gas. There is.

In this case, in the carbonaceous combustion process in the oil shale solid particles, the reaction gradually progresses from around the solid particles toward the inside. This combustion reaction rate is fast on the surface of the solid particle, but as the reaction progresses inside, the rate at which oxygen diffuses into the solid particle becomes slower, so the combustion reaction rate also becomes slower. Therefore, the smaller the solid particle diameter is, the faster the oxygen diffusion rate is, so the combustion rate is also faster, and as a result, the carbonaceous thermal energy recovery efficiency is increased. That is, literature (R, C), Mallon etc.

Quarterly of the Colorado
5chool of Mines.

71 (4) 309 (1976)), 73.
Oil shale (produced in Colorado) with a particle size of When this gas is supplied and combusted, it takes 3 hours to burn 30 wt% of carbon. On the other hand, the particle size is 10
If the combustion time is reduced to a certain degree, the combustion time will be reduced to % under the above conditions.
decrease to a certain degree.

Therefore, the device shape can also be made smaller.

Therefore, in terms of shortening the time required for the combustion process and increasing the thermal energy recovery efficiency, the above-mentioned patent application No. 56-984
The invention of No. 02 is more convenient.

However, a lot of power is required to crush raw oil shale into small particle sizes before supplying it to the preheating and carbonization steps. Therefore, if the lumps that have cracked during the preheating and carbonization steps are crushed into smaller particles, the power required will be reduced.

For example, oil shale raw material 100ψkaku is 101IIl
In the case of grinding to a small particle size of lψ, the particles crushed with a 50 or 50 mnφ neck in the drying and carbonization process are further
Comparing the amount of work in the case of grinding to ttanφ, the amount of work in the former is approximately 50 to 7
Can be reduced to 0% (see Japanese Patent Application No. 116361/1983)
.

Therefore, the method and apparatus according to the present invention can significantly reduce the amount of work compared to conventional methods.

Moreover, the time required for the preheating/carbonization process and the thermal energy utilization efficiency are not much different from those in the case of utilizing the invention of Japanese Patent Application No. 56-98402.

Therefore, as proposed in the present invention, after passing through the carbonization process, the oil shale lumps are transferred to the pulverization process and pulverized to reduce the particle size and adjust the particle size to be almost uniform, and utilize a fluidized bed. It has been found that a preferable carbonization method that combines the advantages of both inventions can be obtained by combining the combustion and cooling steps.

The pulverized particle size varies depending on the physical properties of the oil shale, but
．． A range of about 1 to 10 particles is preferable in terms of forming a fluidized bed state.

Next, an example of an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a system diagram of an embodiment of the present invention which combines a moving grating device called a circular grate or a straight grate, a crushing/sizing device, a fluidized bed device, and a heating furnace.

The oil shale layer 2 loaded on the moving grid 1 moves through the carbonization section A divided by the partition walls X and y, and is exposed to the gas flow supplied to each section to be preheated, dried, and carbonized.

That is, in FIG. 1, on the left side of the preheating/carbonization section A, the moving grid 1 is
Crushed oil shale is loaded on top to form oil shale Ni2, and as the moving grid 1 moves, the oil shale layer 2 first enters the preheating/carbonization section A. A part of the carbonized product gas obtained by cooling and separating the carbonized product generated in the manner described below is transferred to the heating furnace F.
and is carbonized by exposure to a heated gas stream supplied from line 19.

The gas that has flown out of the preheating/carbonization section A via line 3 is entrained with the carbonization product, so it passes through the oil quencher J1 heat exchanger K and is sent to a gas-liquid separation device to separate the product gas, product oil, and water. After separation, the produced oil and water are further separated to remove water in a gas-liquid separator G, and the separated water is discharged from the line 5 to the outside of the yarn. On the other hand, a part of the produced oil passes through line 7 and is circulated and used as circulating oil in quencher J via circulation pump M, and the remainder is drawn out of the υ system through line 8 as product oil. In addition, the generated gas separated by the gas-liquid separator is sucked into the blower N, and a portion is supplied to the cooling tower E through line 9 as cooling gas, and a portion is supplied through line 10 as fuel gas to heating furnace F. However, the remainder is extracted out of the system through line 11 as product gas.

The oil shale layer 2 carbonized in the carbonization section A is supplied to the crusher C, and after being crushed to the particle size necessary to form a fluidized bed in the next combustion tower, the oil shale layer 2 is passed through the downcomer pipe C-1. It is then supplied to the middle lower part of the combustion tower. The solid particles of oil shale supplied to the combustion tower are maintained in a fluidized bed state by the oxygen-containing gas fed through line 15 from the bottom of the combustion tower, and the carbonaceous material in the solid particles is mainly The combustible components are combusted, and the combustion exhaust gas is discharged from the upper part of the combustion tower through line 16 and sent to the lower part of the heating furnace F.

Gas containing oxygen, which is sent to the combustion tower via line 15, is sucked in from line 12 by blower P, preheated in a heat exchanger, passed through line 13, and indirectly heated in heating furnace F (line 14). ) is used. Further, a part of the air may be used as combustion air for the heating furnace F through the line 15'.

The solid particles after burning the combustibles in the combustion tower are transferred to the middle lower part of the cooling tower E mainly by their own weight through the downcomer pipe D-1 installed at the middle upper part of the combustion tower. , cooling 4FF
A fluidized bed is formed by the cooling gas (in this case, a part of the carbonized gas) fed from the bottom through line 9, and the sensible heat held by the solid particles is transferred to the cooling gas, so that approximately After being cooled to about 100 to 150° C., it is discharged from the outlet of the middle L section to the outside of the system as waste solid through line E-1.

In the heating furnace F, the amount of heat generated by combusting a part of the carbonized gas supplied from the line 10 is transferred to the exhaust gas discharged from the upper part of the cooling tower E through the line 18, so that the gas is heated to a high temperature. The exhaust gas from the cooling tower is supplied as heating gas to the preheating/carbonization section A through line 19.

The combustion gas in the heating furnace F uses its sensible heat to preheat the oxygen-containing gas flowing through the line 15 in the heat exchanger Q, and then is discharged to the outside of the system through the line 20.

In this way, the cooling gas of the cooling tower E (preheating/carbonization section A
It is desirable to recirculate and use a part of the carbonized gas as the heating gas).

As mentioned above, this method recycles the carbonized gas that does not contain oxygen as the heating gas in the carbonized distillation section A, so combustion of the gas and oil does not occur, so high quality product gas and oil can be recovered. be able to.

The optimum temperature range in each section varies depending on the physical properties of the oil shale, but the carbonization section A shown in the method shown in Figure 1 is 30
0 to 900°C (preferably about 350 to 750°C), combustion tower temperature is 500 to 11o.

°C (preferably 700-900 °C), cooling tower E is 100 °C
A temperature range of about 200° C. is preferred.

The oxygen-containing gas fed into the combustion tower may be pure oxygen gas, but air is generally used as described above. Further, combustion exhaust gas containing residual oxygen may also be used for circulation.

Although the crusher C is shown connected to the moving grid type device and the combustion tower in the embodiment shown in FIG. 1, it may be a separate device from the moving grid type device or the combustion tower. When these devices are connected, solid particles can be processed at high temperatures, so no heat is released, resulting in a device with high thermal efficiency.

On the other hand, in the case of a connected structure, the crushing device C must be able to withstand high temperatures, but if it is a separate device, low-temperature processing becomes possible.

The pulverizer C not only pulverizes oil shale lumps into small particle sizes, but also pulverizes solid particles into solid particles in the particle size range necessary to form a fluidized bed state in the next combustion tower. Preferably, it also has the function of classifying into groups.

As explained above, the method of the present invention uses gas heated by an indirect heater, that is, high-grade heat, only for the carbonization of hydrocarbon compounds, which is the original purpose of oil shale carbonization, and a large amount of effective heat is used. It is easy to understand that the present invention is an excellent method for recovering oil from oil shale, as more effective heat can be recovered in a short time and efficiently from waste solids containing carbonaceous components. .

The device shape, piping joint positions, etc. shown in FIG. 1 used to explain the above embodiments are not restricted to the above drawings, and as long as they do not depart from the idea of the present invention. good.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of an embodiment of the present invention. Sub-agent 1) Akira Sub-agent Ryo Hagi Hara -

Claims (2)

[Claims] (1) When recovering oil and combustible gas by thermally decomposing oil shale, first a layer of oil shale agglomerates consisting of coarse particles is formed on a horizontal surface, and the layer is continuously moved horizontally. A non-oxidizing high-temperature heated gas is passed through the layer to heat the granules to a high temperature of 300 to 900°C to carbonize the hydrocarbon compounds contained in the granules, and the carbonization product is cooled and air heated. After recovering oil and combustible gas by liquid separation and pulverizing and adjusting the remaining granules with different particle sizes into powder and granules with the particle size necessary to maintain a fluidized bed state,
The powder and granules are transferred to the subsequent combustion process, where a fluidized bed is formed by a flow of oxygen-containing gas, and the heat is recovered while burning the combustibles that could not be thermally decomposed in the carbonization process, and the remaining powder and granules are is transferred to the final cooling step to form a fluidized bed state with a cooling gas flow, while transferring the sensible heat held by the residual powder to the cooling gas, discharging the cooled waste solid from the system, and cooling it. A method for recovering oil and gas from oil shale, characterized in that heat is also recovered from process exhaust gas. (2) A wind box is equipped with a moving grid installed horizontally and configured to be movable continuously in one direction along the surface thereof, and a wind box divided by two partition walls that cross the moving grid, and a wind box with a preheating A carbonization product outlet is located at the lower part of the carbonization gas inlet, an oil shale supply port is located at the upper part of the moving grid of the partition wall on the upstream side with respect to the moving direction of the partition wall, and a preheating port is located at the upper part of the moving grid of the downstream partition wall. A movable grid type device having a preheating/carbonization section equipped with a carbonized granule outlet, a pulverizer equipped with a residual granule inlet on one side and a powder outlet on the other side, and a flow formed therein. A powder inlet opening at the middle lower part of the bed, a residual powder outlet at the middle upper part of the fluidized bed, an oxygen-containing gas inlet at the lower part, and a combustion gas outlet at the upper part. A combustion tower with a high temperature residual powder inlet in the middle lower part of the fluidized bed formed inside, a cooled waste solids outlet in the middle upper part of the fluidized bed, and a cooling gas inlet in the lower part. ,
A cooling tower comprising a cooling exhaust gas outlet at the top, a cooling separation device having a carbonization product inlet on one side and a carbonization product gas outlet and a carbonization product oil outlet on the other side, and combusting a part of the carbonization product gas, and A heating furnace that heats another part of carbonized gas by indirect heat exchange is installed in parallel, and the remaining granule outlet of the movable grid device, the residual granule inlet of the pulverizer, and the powder outlet of the pulverizer. The granular material inlet of the combustion tower, the residual granular material outlet of the combustion tower, and the residual granular material inlet of the cooling tower are connected via downcomer pipes, and the carbonized product outlet of the preheating/carbonization section is cooled. , is connected to the carbonization product inlet of the separation device, and the carbonization product gas heated in the heating furnace is connected to the inlet of the preheating/carbonization section.Recovering oil and gas from oil shale. Device.