JPS6021678B2 - pyrolysis equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluidized bed type pyrolysis apparatus for pyrolyzing organic matter such as municipal waste to recover gas and the like.

In the so-called single-column fluidized bed pyrolysis method, in which organic matter is thermally decomposed in a fluidized bed using inert particles such as sand as a heating medium, the amount of heat required for the endothermic reaction is supplied by partially burning the raw material organic matter. Because of this necessity, the produced gas is diluted by the inert combustion exhaust gas, resulting in a decrease in gas calories and a drawback that the recovery value record is significantly impaired.

Moreover, since carbon adheres to the surface of the inert particles and the flow conditions change, it is necessary to constantly extract the carbon and regenerate it through separate combustion equipment, which causes troublesome operation. On the other hand, as shown in Fig. 7, for example,
A pyrolysis fluidized bed A and a combustion fluidized bed chamber C are installed together, and the rain layer is connected by two inclined pipes B, and the heat medium particles are circulated between the two layers through the inclined pipes B to generate the energy necessary for pyrolysis. There is a so-called two-column circulating fluidized bed system that supplements the amount of heat.

This method is an excellent method that compensates for the disadvantages of the single column type, as the produced gas is less likely to be diluted by combustion exhaust gas, and not only can high gas calories be obtained, but also the regeneration of inert particles is automatically performed. I can say that. However, in this method, in order to smooth the movement of the heat carrier particles in the phrenic tube C, it is necessary to set the phrenic tube at a steeper slope than the angle of repose of the particles. Fluidized bed height increases. This not only makes the entire apparatus high-rise and uneconomical, but also has the drawback of easily interfering with the smooth flow of the fluidized bed. Furthermore,
When dealing with municipal waste, etc., it is necessary to extract inorganic residues such as glass and metals in the raw material, but in the case of a two-column type, extraction from two fluidized beds is required. There are disadvantages such as complicated equipment and operation. Even in the case of a single-column system for this extraction, the equipment and operation thereof are not easy because it is necessary to prevent the dangerous pyrolysis gas from leaking. The present invention enables the lower portions of a pyrolysis fluidized bed chamber and a combustion fluidized bed chamber to be conveyed, and changes the differential pressure at the top of both fluidized bed chambers over time to cause heat transfer particles to alternately move back and forth between the two fluidized beds. , except for the above-mentioned drawbacks of the conventional type, can increase the calorie of the generated gas compared to the conventional single-column type, and can automatically regenerate the heat transfer medium particles, making it different from the conventional two-column type. In contrast, by lowering the height of the fluidized bed, the device can be made smaller and it is easier to maintain smooth flow of the fluidized bed. In addition, inorganic residue can be extracted at the same location, and there is no need to extract inorganic residue from the pyrolysis atmosphere, which is essential for both single-column and dual-column types, and there is no need to use extraction equipment or operations. It is an object of the present invention to provide a pyrolysis apparatus that can simplify the process. The present invention provides a pyrolysis fluidized bed chamber and a combustion fluidized bed chamber that communicate with each other above the dispersion plate in the lower part, and has a differential pressure change mechanism that changes the differential pressure at the top of both fluidized bed chambers over time. This is a pyrolysis device characterized by:

To explain the present invention with reference to the drawings, FIG. 1 shows a pyrolysis fluidized bed chamber E using particles such as sand as a heat medium.
The combustion fluidized bed chamber F is a partition wall 4 having a communication hole 3 at the lower end.
The gas dispersion plates 5 at the bottoms of both fluidized bed chambers are tilted as shown in the figure to make the approximately central part of the bottom of the combustion fluidized bed chamber F the lowest, and the inorganic residue extraction pipe 6 It is written as a lotus.

At the bottom of the gas distribution plate 5, a pyrolysis side gas chamber 8 and a combustion side gas chamber 9 are separated by a partition wall 7 provided at a position continuous with the partition wall 4.
is formed. The pyrolysis side gas chamber 8 is connected to an inert gas supply pipe 10 such as steam or gas in which a part of the pyrolysis generated gas is recirculated, and the combustion side gas chamber 9 is connected to an air supply pipe 11. has been done. In addition, a pyrolysis product gas outlet pipe 14 is connected to the upper part 12 of the pyrolysis fluidized bed chamber E, and a combustion gas outlet pipe 15 is connected to the top 13 of the upper part of the combustion fluidized bed chamber F.
are linked together. 16 in the figure is a raw material supply combination device;
17 is a double discharge valve for removing inorganic residue, 1 is a pyrolysis fluidized bed, and 2 is a combustion fluidized bed. Thus, the 0 top pressure Pg at the top 12 at the top of the pyrolysis fluidized bed chamber 1 is kept almost constant, and the top pressure Pi at the top 13 at the top of the combustion fluidized bed 2 is varied to obtain the pressure shown in FIG. As shown in Figure 2, by controlling the differential pressure at the top of the column so that it changes alternately between positive and negative over time, it is possible to cause the heat carrier particles to alternately move back and forth between both fluidized beds.

Through this reciprocating movement of the heat carrier particles, the amount of heat required for the endothermic reaction of pyrolysis is replenished by the heat carrier particles heated by combustion of char etc. in the combustion fluidized bed, and the pyrolysis reaction is carried out. Continued.

Gas mixture between the two fluidized beds occurs to some extent due to the zero movement of the heating medium particles, but this amount is small compared to the amount of generated gas, so the calorie content of the generated gas is high, and it also adheres to the heating medium particles. The carbon is burned during the combustion process, and particles can be automatically regenerated. In addition, the inorganic residue in the raw material can be extracted by going up and down the inclined gas distribution plate and passing through the flow holes 3 and being extracted from only one fluidized bed. By providing the extraction pipe 6 on the combustion fluidized bed side as shown in the example shown in Fig. 1, it is no longer necessary to extract inorganic residue from the pyrolysis atmosphere, and dangerous pyrolysis gases can be extracted without leaking. Since there is no need to do this, the extraction device and operation become simpler. If the intention is to extract and recover valuable metals such as copper and aluminum from the raw materials in a reduced state, it is of course possible to conversely provide the extraction pipe 6 on the pyrolysis fluidized bed side. However, in this case as well, the extraction position is at the same place, so it is advantageous compared to the conventional 2* type. Compared to the conventional two-column type, this system is not only more reliable in operation because the movement of the heat medium and particles is forcibly performed by the differential pressure between the columns, but also eliminates the need to increase the height of the fluidized bed. Because of this, the device becomes smaller and it becomes easier to maintain smooth flow of the fluidized bed. As a control method for the port top differential pressure, the top pressure Pi is changed as shown in Fig. 2 at the upper limit, neutral N, and lower limit L of each layer.
This is possible only by detecting the bed temperature of the pyrolysis fluidized bed 1.

For example, under the condition of Pi<Pg, the level of the pyrolytic fluidized bed 1 decreases, and when the level of the pyrolytic fluidized bed 1 reaches the lower limit L' (position shown in Figure 1), Pi is controlled and Pi= Let it be Pg. Pi can be easily controlled by a damper (not shown) provided in the combustion gas outlet pipe 15 system. Layer level is neutral N
The bed temperature of the pyrolysis fluidized bed 1, which had once risen, starts to drop when reaching the preset lower limit temperature, but when it reaches the preset lower limit temperature, Pj is controlled so that Pi > Pg, and the level of the combustion fluidized bed 2 reaches the lower limit L. When P is reached, P is set so that Pi=Pg again.
Control i. At this time, the temperature of the pyrolysis fluidized bed 1 rises once and then starts to fall, so after reaching the lower limit temperature, Pi is controlled so that Pi<Pg and it returns to the position shown in Figure 1. . By repeating such cycles, thermal decomposition is reliably continued within a certain temperature range. In controlling the differential pressure at the top of the tower above, Pg was kept constant and only Pi was varied, but this is easier to control in the combustion exhaust gas system, and conversely, Pi is kept constant and only Pg is varied. Of course, it can be controlled by changing both of them. Incidentally, by setting the lower limit L of the bed level sufficiently higher than the upper end of the fluidizing hole 3, it is possible to prevent excessive gas mixing between both fluidized beds. In cases where the content of plastics etc. in the raw materials is high, char generated by fine decomposition may be slightly generated.
Therefore, in many cases, the amount of heat required for the endothermic reaction cannot be compensated for only by burning the char.

In such a case, as shown in Fig. 6, the combustion fluidized bed 2'
By making the partition of the combustion side gas chamber 9' narrower by △ than the partition of the partition wall 4', the gas from the pyrolysis side gas chamber 8' (part of the generated gas from the pyrolysis fluidized bed 1') It is preferable to directly feed a part of the combustion fluidized bed 2' into the combustion fluidized bed 2'. As shown in Fig. 6, the partition wall 7' is connected to the combustion fluidized bed chamber F.
By arranging the gas from the pyrolysis side chamber 8' to be blown into the combustion fluidized bed chamber F, the mixing rate of combustion gas mixed into the pyrolysis product gas can be reduced. can be further reduced.

Furthermore, it is also possible to adjust the position of the partition wall' depending on the raw material to change Δ (the adjustment device is not shown). In FIG. 6, 5' indicates a gas distribution plate, and 8' indicates a gas chamber on the thermal decomposition side. 3, 4 and 5 show other embodiments. In this example, as shown in FIGS. 3 and 4, the pyrolysis fluidized bed 101 is provided sandwiched between two combustion fluidized beds 102 and 1002', and there are flow holes lo3 and lo3 at the lower ends, respectively.
The gas dispersion plate 105 at the bottom of these fluidized beds is slanted as shown in the figure so that approximately the center of the bottoms of both combustion fluidized beds is at its lowest point. Inorganic 0 residual liquid extraction pipe 106, 106
' has been contacted. Note that the inorganic residue extraction pipe 106 may be provided only at the bottom of the combustion fluidized bed on one side, for example, the bed 102, with the gas distribution plate 105 oriented in one direction. (In this way, the inorganic residue extracting device can be installed in a separate place.) The lower part of the gas distribution plate 105 is connected to the partition walls 107, 107' provided in a continuous position with the partition walls 104, 104'. A chamber 108 and combustion side gas chambers 109, 109' are formed. As in the example shown in FIG. 1, an inert gas supply pipe 110 is connected to the pyrolysis side gas chamber 108, and air supply pipes 111, 111' connected to a compressed air source 1201 are connected to the combustion side gas chambers 109, 109', respectively. Connect. A pyrolysis gas outlet pipe 114 is provided at the top 112 above the pyrolysis fluidized bed, and combustion gas outlet pipes 115, 115' are provided at the top 113, 116'35 above the combustion fluidized bed, respectively. The outlet pipes 115, 115' are connected to a three-way damper 118 having a valve plate 119. In the figure, reference numeral 116 indicates a source supply device, and reference numerals 117 and 117' indicate double discharge valves for removing inorganic residue grooves. The control method in this case is similar to the previous example, in which the tower top pressure Pg of the column term 112 above the pyrolysis fluidized bed is kept approximately constant, but the column terms 113 and 113' above both combustion fluidized beds are
By changing the tower top pressures Pi, , Pi2, as shown in Fig. 5, if the differential pressure at the top of the tower is made to alternately change between positive and negative over time, the heat carrier particles can be separated into the pyrolysis fluidized bed and the combustion fluidized bed. It is possible to alternately move back and forth between the two.

In this case, unlike the previous example (example in Figure 1), the pyrolysis fluidized bed 1
While the level of 01 is kept almost constant at neutral N', only the level of combustion fluidized bed 102, 102' is set to the upper limit, neutral N,
At the lower limit L position, the heat carrier particles can be moved back and forth by moving up and down depending on changes in the column top pressures Pi, Pi2. This control is also possible only by detecting the lower limit L of the bed level and the bed temperature of the pyrolysis fluidized bed 101. That is, Pi,>Pg>Pi2
And the combustion fluidized bed 1 under the conditions of Pi, - Pg = Pg - Pi2
The level of 02 falls, but when the level of the combustion fluidized bed 102 reaches the lower limit L (the position shown in Fig. 3), Pi, and P
i2 is controlled to make Pi,=Pg,Pi2. Simultaneous control of Pi and Pi2 can be easily achieved by alternately throttling the gas outlet with the valve plate 119 of the three-way damper 118. The layer level of the combustion fluidized beds 102, 102' is the pyrolysis fluidized bed 1.
Same as 01, when reaching the neutral N', the bed temperature of the pyrolytic fluidized bed 101, which had once risen, starts to fall, and when it reaches the lower limit temperature, Pi2>Pg>Pi4 and Pi2-Pg=P
g-Pi. Pi, and Pi2 are simultaneously controlled so that. Next, when the level of the combustion fluidized bed 102' reaches the lower limit L, if control is again made so that Pi, = Pg = Pi2, the temperature of the pyrolysis fluidized bed 101 will similarly rise once and then drop. Since the temperature starts to decrease, when the temperature decreases, then Pi,>Pg>Pi2 and Pj, -Pg=Pg-Pi2
The robot is controlled so that it returns to the position shown in FIG. 3 again. By repeating such cycles, thermal decomposition is reliably continued within a certain temperature range. In the example shown in FIG. 3, the level of the pyrolysis fluidized bed 101 can always be kept constant compared to the example shown in FIG. Since heat transfer particles can always flow into the pyrolytic fluidized bed 101 to supply heat when the bed level changes in ', there is an advantage that temperature changes in the pyrolytic fluidized bed can be reduced. In the example shown in FIG. 3, depending on the raw material composition, the partition of the gas distribution plate of the combustion fluidized bed is made narrower than the partition of the fluidized bed, as shown in FIG. Of course, similar advantages can be obtained.

In the above explanation, the pyrolysis raw material is mainly city waste, but it is of course possible to use the present invention for pyrolysis gasification of coal, etc.

In this case, the raw material itself can be made into heating medium particles by crushing the coal to a small particle size without using sand as the heating medium particles. In the illustrated example, the outer wall of the fluidized bed furnace is rectangular as shown in FIG. 4, but in cases where pressurized conditions are required, such as in thermal decomposition of coal, it is preferable to make the outer wall circular. Even in this case, the column pressure difference that occurs during control is extremely small, so
Both of the partition walls 104 and 0 104' may be formed on a flat plate. The present invention provides a differential pressure variable mechanism that provides a pyrolysis fluidized bed chamber and a combustion fluidized bed chamber that are mutually suitable at the upper part of the dispersion slope in the lower part, and changes the differential pressure at the top of both fluidized bed chambers over time. By being equipped with a It is easy to maintain fluidity, the inorganic residue can be extracted from one place, and there is no need to extract the inorganic residue from the pyrolysis atmosphere, simplifying the extraction equipment and operation. Moreover, it is possible to provide a safe pyrolysis apparatus, and it has an extremely large effect in terms of practical use and resource regeneration. Brief explanation of the drawings Figure 1 is
2 is a cross-sectional view of a pyrolysis apparatus showing an embodiment of the present invention; FIG. 2 is a view showing an example of controlling the tower top pressure in this case; FIG. 3 is a sectional view of a pyrolysis apparatus showing another embodiment; The figure is 1-1 in Figure 3.
Line sectional view, Fig. 5 is a diagram showing an example of controlling the tower top pressure in the example shown in Fig. 3, Fig. 6 is an explanatory diagram of the lower part of the fluidized bed showing another embodiment, and Fig. 7 is the conventional 2* type. Explanatory diagrams of the pyrolysis apparatus are shown.

1,1',101...Pyrolysis fluidized bed, 2,2'
,102,102'... combustion fluidized bed, 3,103,10
3'...Flow hole, 4, 4', 104, 104'
・・・・・・Bulkhead, 5, 5', 105, 105'...
・Gas distribution plate, 6, 106, 106'...Extraction pipe, 7
,7',107,107'...Partition wall,8,8',1
08...Pyrolysis side gas chamber, 9, 9', 109...
...Combustion side gas chamber, 10,1 10...Inert gas supply pipe, 11,111,111'...Air supply pipe, 12,112,13,113,113'...・・・
...Tower top, 14"114'...Produced gas outlet pipe, 15,
115, 115'... Combustion gas outlet pipe, 16, 11
6... Raw material supply device, 17, 117, 117'
...Double discharge valve, 118 ... Three-way damper, 119 ... Valve plate, 120 ... Compressed air source.

Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. A pyrolysis fluidized bed chamber and a combustion fluidized bed chamber are provided in the lower part and communicated with each other above the distribution plate, and a differential pressure that changes the chamber top differential pressure of both fluidized bed chambers over time is provided. A pyrolysis device characterized by being equipped with a change mechanism. 2. A plurality of combustion fluidized bed chambers are provided, and a lower part of each combustion fluidized bed chamber communicates with a lower part of the pyrolysis fluidized bed chamber, and the differential pressure change mechanism adjusts the pressure difference between the chamber tops of each of the fluidized bed chambers. The pyrolysis apparatus according to claim 1, wherein the pyrolysis apparatus is configured to change the temperature over time. 3. The dispersion plate is provided continuously across the pyrolysis fluidized bed chamber and the combustion fluidized bed chamber, and the dispersion plate is inclined, and the lowest part of the inclination is located between the pyrolysis fluidized bed chamber and the combustion fluidized bed chamber. The pyrolysis apparatus according to claim 1 or 2, wherein the pyrolysis apparatus is located directly below any specific fluidized bed chamber among the combustion fluidized bed chambers, and is equipped with a residue discharge mechanism at the lowest part. . 4. The pyrolysis apparatus according to claim 3, wherein the specific fluidized bed chamber is one or more of the combustion fluidized bed chambers. 5. The gas chamber below the distribution plate is divided into a pyrolysis gas chamber and a combustion gas chamber by a partition wall, and the partition wall is provided inside a vertically projected area of the combustion fluidized bed chamber. A pyrolysis apparatus according to claim 1, 2, 3, or 4. 6. The differential pressure changing mechanism is a damper provided in at least one of the produced gas exhaust line of the pyrolysis fluidized bed chamber or the combustion gas exhaust line of the combustion fluidized bed chamber. The pyrolysis apparatus according to any one of items 1 to 5. 7. The combustion gas exhaust systems of the plurality of combustion fluidized bed chambers merge at a merging point, and the differential pressure changing mechanism is provided with an aperture switching damper at the merging point.
The pyrolysis apparatus according to any one of items 6 to 6.