JPS605635B2 - Combustion method using catalyst for carbonized gas - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a direct heating carbonization method for oil shale.
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. The present invention relates to a method of carbonizing oil shale using a hot gas flow obtained by combusting carbonization product gas contained in circulating gas using a device (hereinafter referred to as a moving grid type device).

A method of carbonizing oil shale using a moving grate type device called a circular grate or a straight grate is widely known as a method of firing and cooling iron ore using such a device, which is loaded on a movable grate. The basic method is to heat or cool the solid particles by flowing a gas substantially perpendicularly to the solid particle layer that moves substantially horizontally with the moving grid.

In the method of carbonizing oil shale using this moving grid type device, as mentioned above, the oil shale to be carbonized is loaded on the moving grid, and the oil shale itself moves in a fixed layer and is carbonized. It has the characteristic that it does not turn into powder during the processing process.

As is well known, when oil shale is subjected to carbonization treatment, it not only generates many cracks within the oil shale, but also becomes brittle and easily fractures with the slightest impact, producing powder.

For this purpose, for example, a device (hereinafter referred to as When oil shale is carbonized using a moving bed type device), as the oil shale layer moves, a large amount of oil shale powder is generated due to impact and friction caused by contact between oil shale particles. .

In this way, when a large amount of oil shale powder is generated, the gas flow resistance within the oil shale layer increases, which not only increases the blowing power but also causes uneven flow of gas within the oil shale layer. Furthermore, a large amount of oil shale powder is mixed into the carbonized oil, resulting in a significant deterioration in the quality of the carbonized oil.

For this reason, an oil shale carbonization method using a moving grid type device, which generates very little oil shale powder during the oil shale carbonization process, is considered to be an excellent method.

A method for carbonizing secondary oil shale using a moving grid type device is disclosed in US Pat. No. 3,325,395;4,058,905;4.
No. 082645, etc., and Document 1 [Oil Seale Data Book: U.S. Department of Commerce, National Technical Isoformation Service, P.B. 80-125636 (
Oil Shale Data Book:U. SDE
PARTMENT OF COMMBRCCE, Nati
onalTechnical Information
n Service, PB80-1125636)]
Circular Great Carbonization Process (Circula)
It is introduced in rGra as RetomngProcess). Based on the system diagram introduced in this document 1, an overview of the conventional method and its drawbacks will be explained.

The system diagram shown in Figure 1 is a direct heating system for the Circular Grate carbonization process (CircularGrateRe
toringProcess), a heating carbonization zone W divided by partition walls a and b, a carbon recovery zone X divided by partition walls b and c, a first cooling zone Y divided by partition walls c and d,
The oil shale layer 2 loaded on the moving grid 1 moves through a second cooling section Z divided by partition walls d and e, and is exposed to the gas flow supplied to each section, where it undergoes carbonization, carbon recovery, and cooling. .

That is, in FIG. 1, on the left side of the heating carbonization section W, crushed oil shale is loaded onto the moving grid 1 using an oil shale supply device (not shown), and the oil shale layer 2 is
As the moving grid 1 moves, the oil shale layer first enters the heating carbonization section W, where it is exposed to a hot gas flow obtained by burning the carbonization product gas contained in the circulating gas and subjected to heating carbonization. After that, move to carbon recovery section ×. The oil shale layer that has moved to carbon recovery section is carbonized. Next, the oil shale layer moves to the first cooling section Y, where it is made into a circulating gas flow and cooled, and then moves to the second cooling section Z, where it is further cooled by being exposed to the air flow, and the oil shale layer is After facial heat is collected, it is discharged outside the system. The gas flowing out of the heating carbonization section W and the carbon recovery section
After being separated, one part is sucked into the blower 3 and taken out as a product gas, and the other part is supplied to the first cooling section Y as a circulating gas.

The gas preheated in the first cooling section Y is supplied to the heating carbonization section W by the blower 4, and in the second cooling section Z, the child heat is mixed with the air supplied by the blower 5 and contained in the circulating gas. A part of the carbonization product gas is combusted to produce hot gas, which is then used for heating and carbonization of oil shale. In Figure 1, F
represents raw oil shale, D represents waste shale, A represents air, B represents burner, PC represents compressor and cooler, PG represents product gas, and DOW represents carbonized oil and carbonized water. As mentioned above, the method shown in Figure 1 has the characteristic that the hot gas required for carbonization of oil shale can be obtained by blowing air directly into the circulating gas flow and burning a part of the carbonized synthetic gas. Because the calorific value of the gas is extremely low (e.g. 250
~55 cal/N) As a result, there is a drawback that a special low-calorie burner, cost-burning agent, etc. must be used to burn the gas produced by carbonization. Generally, in order to stabilize the combustion of combustible gas, the flame temperature must be set to 1000qo.
It is necessary to maintain the temperature at ~1500q0, and if this temperature is not achieved, combustion will not continue. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for direct heating carbonization of oil shale using a moving grid type device, which eliminates the above-mentioned drawbacks of the conventional method.

As a result of intensive research by the inventors in order to stably burn the carbonized gas produced in the circulating gas, which has an extremely low calorific value,
A new method for directly heating carbonization of oil shale has been invented in which hot gas for carbonization of oil shale is obtained by burning the gas produced by carbonization using a temperature detection means, an oxygen supply means, and a catalyst means.

That is, the method of the present invention includes providing a temperature detection means, an oxygen supply means, and a catalyst means in the middle of the circulating gas supply line in order to stably burn the carbonized gas in the circulating gas, which has an extremely low calorific value. The temperature detection means detects the temperature of the hot gas that has passed through the catalyst means, and based on the detected temperature, the oxygen supply means supplies air to the circulating gas supply line to maintain the required hot gas temperature. supply to,
This is a direct heating carbonization method for oil shale in which hot gas for carbonization is obtained by burning this air-mixed circulating gas using the catalyst means. A carrier in which noble metals such as Pt and Pd or base metals such as Cr203, C mountain 0, and Mn02 are supported in combination is used.

Hereinafter, details of the method of the present invention will be explained based on embodiments.

FIG. 2 is a system diagram showing one embodiment of a direct heating oil shale carbonization method incorporating the method of the present invention.

In FIG. 2, raw oil shale F is supplied to a hopper 1, and as the oil shale layer a in the moving bed type device 2 flows down, the oil shale in the hopper 1 flows down into the moving bed type device 2.

While the oil shale layer a flows down inside the moving bed type device 2,
It is supplied from the conduit 3 and is exposed to a hot gas flow flowing through the layer to be preheated and dried, and then supplied onto the moving grid 4 of the raw material supply section (1 section) of the moving grid type device, and is then supplied to the oil shale layer b. to form. The oil shale layer b loaded on the moving grid is then moved to section B, which is the heating carbonization section of the moving grid type device, where it is exposed to a hot gas flow and carbonized, and then the oil shale layer b is transferred to the carbon shale layer B, in which oxygen-containing gas flows. Move to the collection section (m section). The oil shale layer, in which the organic carbon remaining in the oil shale was incinerated in section m, was cooled by moving to the cooling section (section W) where cold gas circulated, and the head heat of the oil shale layer was recovered. After that, it is further cooled in a cooling section (V section) by air flow, and then discharged as waste shale D to the outside of the system.

The effluent from the heated carbonization section (section B) is taken out through a conduit 5, cooled by a cooler 6 if necessary, and then integrated into a gas-liquid separation device 7.

In the gas-liquid separator 7, the oil and a small amount of water carbonized in section 0 are separated and sent to a cooler 9 by a gas blower 8 and cooled, and the low-boiling point oil contained in the gas is condensed and separated. After that, a portion of the gas is taken out of the system through conduit 10 as product gas PO. The oil and water separated by the gas-liquid separator 7 and the cooler 9 are transferred to the oil separator 11, where the oil-water separated product oil PO is sent out of the system through a conduit 12, and a small amount of carbonized water W is sent out of the system through a conduit 13. taken out.

A part of the gas sent by the blower 8 is supplied from the conduit 14 to the W section and heated, and then transferred to the conduit 16 by the blower 15.
and is supplied to section B, which is the heating carbonization section of the movable grid type device.

In order to adjust the gas temperature supplied to section D, conduit 1
The combustible content of the gas supplied from 6 is combusted by the catalyst of the catalyst device 17, and the temperature is 45,000 to 800o.
o (preferably 500q○ to 700°C).

As the air necessary for combustion in the catalyst device 17, heated air supplied from a conduit 19 by a blower 18, which is subheated in the V section, is used.

In order to adjust the amount of heated air, the temperature of the hot gas discharged from the catalyst device 17 is detected by the temperature detector 31, and based on this detected temperature, the regulator 3 is adjusted to maintain the hot gas temperature at the required temperature.
2 controls a regulating valve 30 for the heated air flow rate. By this method, the temperature of the gas supplied to the 0 section is stably maintained at the required temperature, and the low caloric IJ- circulating gas can continue to be burned without any auxiliary combustion like burner combustion. Therefore, it is a great advantage of the present invention that the heating carbonization section of the 0 section is stabilized. blower 18
A part of the air sent is supplied from the conduit 20 to the carbon recovery section (m section) of the moving grid type device and is used for incineration of residual carbon in the oil shale. The temperature of the gas flowing out of section m should be adjusted by the heat resistance strength of the constituent materials of the moving grid type device, especially the material of the moving grid, and if the gas temperature is high, the tolerance of the material should be adjusted by the exhaust gas supplied from the conduit 21. The gas temperature is adjusted so that the gas temperature is within this range.

The gas supplied to the moving bed type device 2 is a combustion exhaust gas obtained by combusting part of the outflow gas from the B section and/or a part of the outflow gas from the W section supplied from the conduit 22 in the burner 23 and the blower 24. The combustion exhaust gas of residual organic carbon in the oil shale supplied from the conduit 25 is utilized.

Combustion air is also supplied to the burner 23 from a conduit 26. The temperature of the gas supplied from the conduit 3 to the moving bed type device 12 is set to be below the temperature at which hydrocarbon compounds in the oil shale substantially start to decompose (approximately 350 qo) and above 150 qo (preferably above 200°C). The gas temperature is adjusted by the circulating amount of the outlet gas of the moving bed device, which is supplied from the conduit 28 by the blower 27.

When the gas temperature supplied to the moving bed type device 2 is at a temperature at which the hydrocarbon compounds in the oil shale are substantially decomposed, the exhaust gas taken out of the system from the conduit 29 contains decomposition product gas and Contamination with oil may lead to product loss or require special equipment to recover.
Undesirable.

Moreover, if the gas temperature is below 150 pm, the purpose of the moving bed type apparatus, which is to preheat and dry the oil shale, cannot be sufficiently achieved. In order to achieve the desired water removal within the moving bed type device 2, the oil shale may be retained in a gas flow of 150°C or higher, preferably 200°C or higher for a predetermined time, and then transferred to the moving bed type device 2. so that the temperature at the position above the hot gas inlet of the hot gas inlet and at which the predetermined time required for the oil shale layer a to flow down to the gas inlet is the time required for moisture removal to be 150°C or higher, preferably 20 pi○ or higher. Then, the amount of gas supplied from the conduit 3 is adjusted.

The gas flow rate is adjusted by the amount of fuel gas supplied to the burner 23 from the conduit 22. That is, as is well known in conventional combustion equipment, the amount of combustion air supplied from the conduit 26 to the burner 23 is adjusted according to the amount of fuel gas, and the amount of combustion air supplied to the moving bed type device 2 is adjusted. The amount of circulating gas from the conduit 28 is adjusted so that the gas temperature is constant, and by adjusting the amount of fuel gas supplied from the conduit 22, the amount of combined gas supplied to the moving bed device 2 can be adjusted. The result will be adjusted.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional direct heating carbonization method for oil shale using a moving grid type device, and FIG. 2 is an explanatory diagram of an embodiment of the present invention. Figure 1 Figure 2

Claims (1)

[Claims] 1. A layer of crushed oil shale loaded on a moving grid is heated and carbonized by being exposed to a hot gas flow flowing through the oil shale layer, which is obtained by burning the carbonized gas contained in the circulating gas. the moving grid having a step of passing through a section exposed to an oxygen-containing gas flow flowing through the oil sier layer and/or through a section cooled by the gas flow flowing through the oil sier layer; In the direct heating carbonization method of oil siel using a type device, the carbonization product gas in the circulating gas is combusted by a catalyst means, the temperature of the hot gas obtained by the catalyst means is detected by a temperature detection means, and the temperature of the hot gas obtained by the catalyst means is detected by the temperature detection means. A direct heating carbonization method for oil siel, characterized in that air is supplied to the circulating gas by an oxygen supply means to maintain the hot gas temperature at a required temperature based on the detected temperature.