JPS587483A - Thermally decomposing method of oil shale or oil sand and apparatus therefor - Google Patents

Abstract

PURPOSE:To decompose the titled substances efficiently, by preheating and drying a particulate or granular mineral containing oil, mineral, heating the mineral to under heating at a high temperature while fluidized with a heating gas, separating the formed and gas, cooling the residual solid with a cooling gas, and discharging the solid to the outside of the system by the own wight. CONSTITUTION:A particulate or granular mineral containing oil is fed from a feed inlet 6 into a preheating column and preheated at 150-350 deg.C while kept in a solid-gas fluidized bed state with preheating gas blown from a blowing inlet 7 and dried by evaporating the adhesive moisture and water of crystallization of the mineral containing the oil. The resultant mineral is passed through a downcomer 4, fed to a thermal decomposing column 2 and decomposed at a high temperature of 300-900 deg.C in a fluidized bed state with a heating gas blown from a blowing inlet 9, and the resultant product is discharged from a discharging outlet 10, passed through a heat exchanger 11 and separated into the formed oil and gas in a separator 12, which are collected. The remaining solid is then fed from a downcomer 5 to a cooling column 3, and a cooling gas is fed from a blowing inlet to cool the solid, which is then discharged from a discharging outlet 15 to the outside of the system by the own weight.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves bringing oil-containing minerals such as oil shale and tar sand with a relatively large particle size 1, for example, an average particle size of about 0.1 to 10 mm, held in a fluidized bed state into contact with heating gas. A method for effectively recovering pyrolysis product oil and pyrolysis product gas by pyrolysis under a wide temperature range of about 300 to 900'C, and the equipment used to carry out this method. It is about improvement.

Examples of oil-bearing minerals in the present invention include oil shale and tar sand.

In the following explanation, oil shale will be taken as an example.

Although oil shale has different thermal decomposition characteristics depending on the production area, it generates thermal decomposition product oil and thermal decomposition gas when heated from about 300'C. The amount of oil produced is approximately 400 to 50
It shows a peak in the range of about 0'C, and the amount of produced gas shows a peak in the range of about 450 to 550'C. On the other hand, the decomposition of crystallized water contained in oil shale shows a peak in the range of about 200 to 300'C.

Although the condition varies depending on the deposit of the raw ore, the mining method, the storage method, etc., the moisture attached to the raw ore starts to evaporate at about 300'C.

Conventionally proposed means for directly supplying oil shale to the lower part of a pyrolysis tower using a solid-gas fluidized bed 1 For example, in the method described in US Pat. When extracted from the cracking tower and cooled, it forms an emulsion, making it difficult to separate the produced oil and water.

In addition, the produced oil or produced gas and moisture undergo the following secondary reaction in the thermal decomposition tower.

This causes a decrease in the quality of the produced oil or the calorific value of the produced gas.

Co + H20-> CO2+ H2CH4
+ H20-> GO+ From the points above 5H2,
and moisture generated by preheating.

It has been found that the above problems can be solved by performing the two steps of preheating and thermal decomposition in separate columns in order to separate the oil and gas produced by thermal decomposition.

The temperature range of the preheating tower is preferably about 150 to 3000C.

As a similar means to the present invention, as previously proposed by the present inventor, oil-bearing minerals are moved by their own weight between a preheating tower, a carbonization tower, a combustion tower, and a cooling tower, each of which forms an independent fluidized bed. There are methods to effectively preheat, carbonize, burn, and recover heat while maintaining the temperature.

The content of oil shale varies considerably depending on its production area, but it generally contains MgCa (CO3)2, CaCO3°N
Contains carbonates such as aHCO3, NaAl (OH)2 C03, etc. in an amount of about 3-19 wt%. When these are heated, they release CO2 in a temperature range of about 600@C or more and cause the next thermal decomposition reaction.

MgCa (CO3)2 → Mg
O+ CaO+ 2CO2Ca COa →
CaO+ C02CaC03+ 5i02
→ Ca5i02 + CO2NaAl
(OH)2. C0a->-Naf, 03+'Alf
f3+H20+'-COs2 2 2 Since the above reactions are endothermic reactions, if these reactions occur at high temperatures, the effective amount of heat will be wasted due to the heat of the decomposition reaction.

The amount of heat required for this deashing acid is about 1% of the total heat generation 1 in the case of oil shale with a low carbonate content, compared to the total calorific value of the produced gas and produced oil. If the salt content is high, it can reach about 20% of the total calorific value.

Therefore, when oil shale containing a large amount of carbonates is burned in a combustion tower, most of the generated heat is consumed as heat of decomposition of the carbonates, and the heat cannot be effectively recovered.

Therefore, in the case of oil shale with a high carbonate content, the present invention, which uses three towers: a preheating tower, a pyrolysis tower, and a cooling tower, can effectively thermally decompose the oil shale and generate Oil and product gas can be recovered.

U.S. Patent A 3501394 (1970,0ilS
hale and Tar 5 and P28-30) and A 3784462 (1974, same P66)
-69).

The former combines two towers: a carbonization tower and a combustion tower. The latter is a method in which two towers, a carbonization tower and a combustion tower, are combined and the solid heated in the combustion tower is recycled and used as a heat source for the carbonization tower.

Of oil shale and tar sand, oil shale in particular contains a large amount of adhering water and crystallized water, as described above, and the water content fluctuates rapidly. Therefore, if the preheating/drying process and the thermal decomposition (carbonization) process are performed in the same tower, cooling the mixed gas of produced oil and water will generate a 1: This will complicate the liquid separation operation.

In addition, during the preheating and drying process at 100 to 300'C, oil shale generates cracks in the solid particles when water evaporates, and is further crushed into solid particles with smaller diameters. As a result, a mixture of particles with different diameters is formed, making it extremely difficult to form and maintain a fluidized bed.

As a result, it becomes difficult to maintain stable operation of the pyrolysis (carbonization) process.

For the above reasons, as proposed in the present invention,
By separating the preheating/carbonization step and the thermal decomposition (carbonization) step, stable operation can be maintained, and high-quality product oil and gas can be efficiently recovered.

Next, an example of an actual travel aspect of the present invention will be explained with reference to the accompanying drawings.

In Figure 1, ■ is a preheating tower, and 2 is a thermal decomposition tower.

3 is a cooling tower. Between each group there is provided a downcomer pipe 4 and 5, respectively, in which the solid particles move mainly due to their own weight.

Oil shale A adjusted to have an average particle size of about 0.1 to 10 mm is supplied to the preheating tower 1 from a supply port 6 installed in the preheating tower 1.
The fluidized bed state is maintained by preheated gas introduced from the inlet lower.

At this time, the oil shale is preheated and dried by the preheating gas, and a part of the evaporated adhering moisture and decomposed crystal water are discharged from the preheating tower 1 through the outlet 8 along with the preheating gas.

On the other hand, oil shale has a temperature of 150 to 350 in the preheating tower 1.
Preheated to about °C, the flow in the preheating tower 1 was
It moves down the downcomer pipe 4 to the bottom of the pyrolysis furnace 2 mainly due to its own weight.

The oil shale that has moved into the pyrolysis furnace 2 is heated by heated gas introduced from the inlet 9 at the bottom of the pyrolysis furnace 2. 300-900 while being kept in a fluidized bed state
Since it is heated to about 100 ℃ and does not cause a thermal decomposition reaction, it moves to the upper part of the fluidized bed.

The pyrolysis product gas (high calorie gas) rich in hydrocarbon gas, hydrogen and methane, which is liquid at room temperature and is generated by pyrolysis, is discharged from the upper exhaust port 1o of the pyrolysis furnace 2 together with the heated gas.
The gas is discharged through a heat exchanger 11 and further sent to a cooling/separation device 12 for produced oil and high-calorie gas, and is then sent to a cooling/separation device 12 for producing oil and high-calorie gas.
After being cooled to about 200'C, it is separated into pyrolysis product oil B and high calorie gas C.

On the other hand, the powdery solids of the oil seal pyrolyzed in the pyrolysis furnace 2 pass through the F downcomer 5 above the fluidized bed in the pyrolysis furnace 2 mainly by their own weight.

It is transferred to the bottom of the cooling tower β and maintained in a fluidized bed state by the cooling gas fed in from the cooling gas inlet 13', and at the same time, the sensible heat held by the solid is transferred to the cooling gas, and approximately 400
After being cooled to about ~200°C, it is discharged from the discharge port 15 as waste solids.

The cooling gas is discharged from the outlet 14 at the top of the cooling tower 3.

The cooling gas fed through the inlet port 13 at the bottom of the cooling tower 3 is a thermal decomposition product gas (high calorie gas C) that is circulated and used. The cooling gas discharged from the outlet 14 at the top of the cooling tower 3 has a temperature of 400 to 1000 degrees, which is the temperature required to heat the oil shale to the optimum temperature for thermal decomposition, although this varies depending on the characteristics of the oil shale. After being heated in the combustion furnace 17 to within a range of approximately C, it is fed into the pyrolysis furnace 2 through the inlet 9 at the bottom of the pyrolysis furnace 2.

On the other hand, the preheating gas sent to the lower part of the preheating tower 1 is heated by heating the air E blown by the blower 16 by the heat exchanger 11, and then by heating the air E blown into the lower part of the combustion furnace 17 by the blower 18. The combustion exhaust gas of the combustion furnace 17 generated by using the calorie gas C as combustion air is used.

The preheated gas discharged from the upper exhaust W port 8 of the preheating tower 1 contains a large amount of moisture, and after the moisture is separated as wastewater G in the gas-liquid separator 19, it is discharged as exhaust gas F through the blower 20. Ru.

The exhaust gas exiting the gas-liquid separator 19 is used as preheated gas without passing through the blower 20. Some may be used repeatedly.

As shown in this example, if the pyrolysis product gas is recycled as a cooling gas and a heating gas fed from the lower part of the pyrolysis furnace 2, and the path is separated from the preheating gas, the nonflammable gas Since it is not mixed in, it becomes a high-calorie gas.

In addition, since no oxygen-containing gas is mixed into the preheating gas circulation system, there is no possibility that some of the pyrolysis gas and oil will be combusted, and therefore no disasters such as explosions will occur. .

As shown in E-E, in the present invention, the preheating tower and the pyrolysis tower are separated, so the pyrolysis tower can be operated stably without being affected by changes in the content of water attached to oil shale or crystallized water. Furthermore, by efficiently utilizing the sensible heat of the exhaust gas, it is possible to obtain pyrolysis product oil and product gas with high yield and good quality.

In the second embodiment, the types, levels and numbers of the downcomers 4 and 5, the inlet lower pipes 9 and 13, the discharge ports 8, 10 and 14, etc. are arbitrary, and the preheating tower 1. Pyrolysis tower 2
．． The shape of the cooling tower 3 is also not restricted by the illustrated example.

In addition, in this embodiment, the gas flow for recycling the pyrolysis product gas of the pyrolysis tower and recovering sensible heat from the pyrolysis tower exhaust gas was shown in order to improve thermal efficiency, but the preheating tower,
If a device is used in which a pyrolysis tower and a cooling tower are arranged side by side and the solid particles of oil shale are moved in the order shown in the examples, even if the gases supplied to the lower part of each tower are different gases, This does not depart from the spirit of the present invention.

The adjusted particle size of oil shale is determined by the crushability, specific gravity, etc. of the shale, and is limited to the particle size that can be maintained in a fluidized bed state, so to speak, and is constrained to the value shown in the above theory and open side 7. It's not a thing.

In the above explanation, oil shale was used as an example, but since tar sand has greater strength than oil shale, the method and apparatus of the present invention can be used to effectively remove pyrolysis-produced oil. The produced gas can be recovered.

Next, numerical values measured in an embodiment of the present invention using a device having a configuration similar to that shown in FIG. 1 are shown.
0 Raw materials: US oil shale 100Kg/h standard, inorganic 1i 84.21wt%, organic matter 5.76wt%
, average particle diameter 3.5 mm, moisture content 10.22 wt% (adhered water 8.26 wt%), preheating tower temperature 122°C, pyrolysis tower temperature 51 deC, cooling tower temperature 155°C, feed gas amount, preheating tower 32. 6 Nm/h pyrolysis tower 35.2 Nm3/h, cooling tower
35.2 Nm3/h Pyrolysis product oil 4.93
Kg/h Pyrolysis generated gas (dry soil standard) 768
Nl/hH)25.7, CO2,22,9,
CHi 21.2゜

[Brief explanation of the drawing]

FIG. 1 is a flow sheet showing an embodiment of the apparatus of the present invention. The main symbols in the figure are as follows. 1. Preheating tower 2. Pyrolysis tower 3, cooling tower 4. Downcomer pipe 9, heating gas inlet 10 carbonization product discharge/port 17,
Combustion furnace 18. Blower 19° Gas-liquid separator 20. blower

Claims (2)

[Claims] (1) When recovering oil and high-calorie gas by thermally decomposing oil-bearing minerals, first the granular oil-bearing minerals are fluidized with preheated gas to maintain a solid-gas fluidized bed state, and then the preheated gas is exposed. 150 to 350°C, which is determined depending on the physical properties of the oil-bearing mineral, by transmitting heat to the oil-bearing mineral.
Preheating and drying in which the oil-bearing mineral is preheated to a predetermined temperature within the range of , and the adhering water and crystallization water of the oil-bearing mineral are evaporated into the preheated gas, and the preheated and dried oil-bearing mineral is transferred to the next process mainly by its own weight. The oil-bearing mineral is fluidized by a heated gas so as to maintain a solid-gas fluidized bed state, and the sensible heat of the heated gas is transferred to the oil-bearing mineral so that the oil-bearing mineral changes according to its physical properties. It is heated to a high temperature of 300 to 900' C, which is determined by a pyrolysis step in which the powdery solids produced by the decomposition are transferred to the next step mainly by their own weight;
While the residual solid is fluidized by a cooling gas so as to maintain a solid-gas fluidized bed state, the residual solid is cooled by transferring the sensible heat of the residual solid to the cooling gas, and the waste solid whose temperature has decreased is mainly used as a waste solid. A method for thermally decomposing oil shale or oil sand, comprising: a cooling step in which oil shale or oil sand is discharged to the outside by its own weight. (2) A preheater with an oil-containing mineral supply inlet and a preheated and dried oil-containing mineral outlet in the middle of the inside air fluidized bed, a preheating gas inlet in the lower part, and an outlet in the upper part. The tower has a preheated and dried oil-containing mineral supply port and a granular solid extraction port in the middle of the external solid-gas fluidized bed formed inside the tower.
The pyrolysis tower is equipped with a heated gas inlet in the -F section and a pyrolysis product outlet in the upper part, and a high-temperature granular solid supply inlet and a cooled granular solid in the middle of the solid-gas fluidized bed formed inside. A cooling tower having a cooled waste solids outlet in the lower part thereof, a cold equalization gas inlet in the lower part thereof, and a cooled waste gas outlet in the upper part thereof are arranged in parallel, and the oil-containing mineral outlet in the preheating tower and the oil-bearing mineral in the pyrolysis tower are arranged in parallel. The supply port, the powdery solids outlet of the pyrolysis tower, and the powdery solids supply port of the cooling tower are connected through downcomers, respectively, and pyrolysis product oil is connected to the pyrolysis product outlet of the pyrolysis tower. A pyrolysis device for oil shale or oil sand, characterized in that the pyrolysis device is connected to a cooling and separation device for pyrolysis product gas.