JPH07150151A - Method for gasifying tire chip - Google Patents

Abstract

PURPOSE:To gasify tire chips into a gas which does not contain impurities such as a fine coal powder and has a stable calorific value while reducing the amt. of a waste produced, such as char. CONSTITUTION:Tire chips are gasified by using a packed-bed gasifier having a feed preheating zone, a dry distillation zone, a water-gas producing zone, a combustion zone, and an ash storage zone installed in this order from the upper side. The gasification is done by filling a homogeneous mixture comprising 100 pts.wt. tire chips and 5-200 pts.wt. at least one solid carbonaceous fuel selected from coke, coal, and oil coke into the feed preheating zone to form a packed bed, passing the packed bed continuously or intermittently through all the subsequent treating zones, simultaneously supplying continuously or intermittently a mixture of steam and air to the water-gas producing zone and air to the combustion zone, and taking out a distillation gas and a fuel gas mainly comprising water gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for gasifying old tires for effective use. More specifically, the present invention provides a clean, stable amount of heat that is generated from char and does not contain impurities such as pulverized coal-like soot and dust containing char as a main component, and that waste such as char is generated. The present invention relates to a new gasification method for old tires, which can reduce the amount.

[0002]

2. Description of the Related Art Conventionally, as a method for gasifying old tires, a batch method, a fluidized bed method, a continuous filling method and the like are known. The batch method is one in which old tires or old tire chips are filled in a gasification furnace and ignited, but there is a drawback that the components of the generated gas change with time and a stable calorific value cannot be obtained. Further, in the fluidized bed type, a clean gas cannot be obtained because the char of the tire is crushed and diffused in the gas.
Therefore, there is a drawback that a large amount of waste must be discarded if the mixture of pulverized coal-like soot dust containing char as a main component is not allowed. Further, the continuous filling method involving an aqueous reaction, because the tire chips are softened by heating, the furnace is closed, a stable combustion zone is not formed due to the obstruction of the air flow, and the aqueous reaction is also insufficient. Stable operation could not be obtained and it was not put to practical use. Further, the continuous filling method that does not involve an aqueous reaction has a drawback that char is discharged as it is because an aqueous reaction does not occur, and that its treatment is difficult.

[0003]

DISCLOSURE OF THE INVENTION The present invention has drawbacks such as the blockage of the furnace due to the softening of the tire of the continuous filling type which can be expected to have the simplest operation in the conventional gasification method of old tires. Overcome, generate from char, and contain almost no impurities such as pulverized coal-like soot and dust containing char as a main component, clean, stable heat quantity is obtained, and the amount of waste such as char is suppressed. The object of the present invention is to provide a method for gasifying old tires that can prevent damage due to steel in the tires.

[0004]

The present inventors have conducted various studies to develop a gasification method for old tires having the above-mentioned preferable characteristics, and as a result, have mixed a predetermined amount of carbonaceous solid fuel as a raw material. It was found that the object can be achieved by sequentially performing the operations of preheating, dry distillation, water gasification, and combustion using the tire chips described above, and based on this finding, the present invention has been completed.

That is, the present invention uses a packed bed gasifier equipped with a raw material preheating zone, a dry distillation zone, a water gasification reaction zone, a combustion zone, and an ash storage zone in this order, and for tire chips as a raw material. On a weight basis, at least one kind of carbonaceous solid fuel selected from coke, coal and oil coke is uniformly mixed and used, and this raw material is charged and filled in the raw material preheating zone, The operation of sequentially moving this packed bed to the lower processing zone is carried out continuously or intermittently, and a mixture of air and water vapor is continuously or intermittently supplied from below the packed bed to obtain a dry distillation gas and a water gas. The present invention provides a method for gasifying tire chips, which is characterized in that a fuel gas mainly containing is extracted.

The raw material used in the method of the present invention is 5 to 200% by weight, preferably 5 to 200% by weight, based on the weight, of at least one carbon solid fuel selected from coke, coal and oil coke with respect to tire chips. It is necessary to add 10 to 150% by weight, more preferably 30 to 120% by weight. The carbonaceous solid fuel has a particle size of 5 mm or more, preferably 5 to 100 mm, more preferably 20 to 50 m.
m. This carbonaceous solid fuel is interposed between the tire chips, and if only the tire chips are used, they are softened by heating and stick to each other to prevent ventilation such as air, blockage of the furnace,
Although a great change in the gas generation situation occurs, such inconvenience can be avoided and ventilation of air or the like can be improved. In addition, the decomposed product of char and pyrolysis carbon mainly composed of pyrolytic carbon and the carbonaceous solid fuel are burned later to generate a part of combustion gas. The raw material may be stored in a fuel injection chamber having a double lid structure having an upper outer lid and a lower inner lid before being sent to the raw material preheating zone.

Combustion gases, which will be described later, and various fuel gases rise in the raw material preheating zone and the carbonization zone, and the heat possessed by these gases is given and heated. The fuel gas in the raw material preheating zone also contains the dry distillation gas produced in the dry distillation zone. The water gas described later directly contacts the dry distillation zone at a high temperature, and since this water gas does not contain oxygen gas, the raw material preheated by the heat stored therein can be dry distilled. Next, the dry-distilled high-temperature raw material is sent to the water gasification reaction zone and causes a water gasification reaction with a mixture of steam and air supplied to the zone. This water gasification reaction is an endothermic reaction, and the heat possessed by the high-temperature combustion gas generated in the combustion zone described later is used as the heat source required for this reaction.

Further, since the water gasification reaction is endothermic, the temperature of the reaction zone is lowered, so that, for example, in a steel tire, the steel may be completely melted as in the case of simply air burning. In addition, a large block is not generated, and therefore, the packed bed in the reaction zone can be smoothly moved.

The solid residue after the gas content is generated in the water gasification reaction is mainly composed of a carbon layer, and this layer is burned by the air in the air-fuel mixture in the combustion zone where the gas is moved and filled. The generated heat of combustion rises in each zone in the device and gives its own heat to each zone.

The mixture of steam and air supplied from below the packed bed may be preheated,
The mixing ratio of air and steam is usually 50 to 95% by volume of air.
And 50 to 5% by volume of water vapor, preferably 70 to 85% by volume of air and 30 to 15% by volume of water vapor. The amount of air used is 1000 per ton of the raw material mixture.
To 3000 Nm ³ , preferably 1500 to 2600 Nm
It is selected in the range of ³ .

The solid combustion residue in the combustion zone is 20 to 100 m, which is ash content, or, when a steel tire is used as a raw material tire, ash content and a steel wire such as a piano wire partially oxidized and melted.
However, such combustion residue is accumulated in the ash storage zone. The preferred embodiment of operation in this ash storage zone may be to discharge into a receiver below the combustion zone, but in particular to an eccentric rotary grate as described below. The combustion residue such as ash is scraped off by an ash scraping blade or the like and discharged from an outlet at the bottom of the device.

Next, a packed bed gasifier which is preferably used for carrying out the method of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of the apparatus. Reference numeral 1 is a raw material supply hopper, 2 is a raw material charging chamber having a double lid structure including an upper outer lid 3 and a lower inner lid 4, and 5 is for feeding raw material. Rotating chute, 6 is an eccentric rotary grate for uniformly pushing down the generated ash, and 7 is a rake for collecting the ash extruded from the eccentric rotary grate and discharging it from the ash discharge port 8 to the outside of the apparatus. An ash content blade, 9 is a gas inlet for supplying a mixture of air and water vapor into the apparatus, and 10 is a generated gas outlet.

The raw material charged into the raw material charging chamber 2 from the hopper 1 is supplied to the rotary chute 5 in an appropriate amount by operating the upper outer lid 3 and the lower inner lid 4. This double lid structure is suitable for continuously supplying the raw material, and helps to stabilize the gas generation by eliminating large fluctuations in gas temperature and gas concentration.
Further, the rotary chute is suitable for uniformly filling the raw material into the apparatus. The packed bed is placed on the eccentric rotary grate 6 and the lower part of the packed bed is crushed by being pressed against the wall surface during rotation by the eccentric effect of the rotary grate even if there are some lumps. To be done. The ash produced by the gasification of the raw material is extruded on average by the eccentric rotary grate 6 provided at the lower part of the device, and is collected by the ash scraping blade 7 provided below it to remove the ash at the bottom of the device 8.
Is easily and continuously discharged out of the apparatus.

Further, as another example of the packed bed gasifier, one in which the moving operation between the zones of the packed bed is performed stepwise will be described below. At the bottom of each zone, ventilable and detachable receiving and supporting members are provided in a pair up and down, and at least the lower receiving and supporting members are inserted to support a packed bed made of the raw material or a predetermined processed product thereof and subjected to a predetermined treatment. After that, by pulling out the lower support member with the upper support member inserted, the support of the lower portion of the packed bed which has been sufficiently treated and has been treated is removed, and moved to the next zone. The receiving and supporting member may be a single member that can be inserted and removed from one side, but a pair of members that can be inserted and removed simultaneously from the left and right are used. The ventilation structure is not particularly limited. Shape, porous shape, wire mesh shape, comb tooth shape, fork shape and the like.

Further, the lower receiving and supporting member may be a rostrut which is openable and closable horizontally and vertically downward with respect to a fulcrum provided on the side wall of the device as an axis, for example, a butterfly-shaped rostrut.

[0016]

EFFECT OF THE INVENTION According to the method of the present invention, a clean and stable amount of heat generated from char and containing almost no impurities such as pulverized coal-like soot dust containing char as a main component can be obtained.
Moreover, it has a remarkable effect that the amount of waste such as char can be suppressed.

[0017]

EXAMPLES Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. The amount of air introduced is the value obtained by converting the capacity value per ton of the raw material mixture into that under standard conditions, and the amount of introduced steam is the weight value per ton of the raw material mixture.

Example 1 A packed bed gasifier equipped with a raw material preheating zone, a carbonization zone, a water gasification reaction zone, a combustion zone, and an ash storage zone in this order was used, and 50% by weight of 32 divided tire chips were used as a raw material. Further, a mixture of 50% by weight of coke having a particle size of 20 to 40 mm was charged for 1 t per hour, and the gasification was performed by adjusting the amount and temperature of introduced air and the amount of introduced steam as shown in Table 1.
The results are shown in Table 1, and FIG. 2 shows the relationship between the amount of produced gas, that is, the gas generation amount, and the elapsed time of gas generation with a solid line.

Comparative Example Example 1 except that fine coke having a particle size of 2 to 4 mm was used.
Gasification was carried out in the same manner as in. As a result, the furnace was clogged, the amount of gas generated was fluctuated, and stable operation was not possible. In FIG. 2, the broken line shows the relationship between the amount of produced gas, that is, the gas generation amount and the elapsed time of gas generation.

Example 2 The proportion of tire chips and coke was 70% by weight, respectively.
And gasification were carried out in the same manner as in Example 1 except that the contents were changed to 30% by weight. The results are shown in Table 1.

[0021]

[Table 1]

Example 3 Gasification was carried out in the same manner as in Example 1 except that the same equipment as in Example 1 was used, the coke blending ratio was variously changed from 0 to 240%, and the operation was continued for 1 week. If the coke content is less than 5% by weight, the furnace will be blocked and the operation stability will be 20%.
%, And when it exceeds 200% by weight, the amount of tire chips is small and sparse, so that the dry distillation gas varies and the operation stability rate becomes 90% or less. FIG. 3 is a graph showing the relationship between the coke mixing ratio and the operation stability ratio.

[Brief description of drawings]

FIG. 1 is a schematic view of an example of a packed bed gasifier used to carry out the method of the present invention.

FIG. 2 is a graph showing a relationship between a gas generation amount and an elapsed time of gas generation.

FIG. 3 is a graph showing the relationship between the coke mixing ratio and the operation stability ratio.

[Explanation of symbols]

 1 Hopper 2 Raw material charging chamber 3 Upper outer lid 4 Lower inner lid 5 Rotating chute 6 Eccentric rotating grate 7 Ash scraping blade 8 Ash discharging port 9 Gas inlet 10 Gas generating outlet

Claims (2)

[Claims] 1. A packed bed gasifier equipped with a raw material preheating zone, a carbonization zone, a water gasification reaction zone, a combustion zone, and an ash storage zone in order from the top, and a tire chip as a raw material on a weight basis. Solid carbonaceous fuel 5 selected from the group consisting of coke, coke, coal and oil coke 5
~ 200% of a uniform mixture is used, the raw material is introduced into the raw material preheating zone and filled, and the operation of sequentially moving the filled bed to the lower processing zone is performed continuously or intermittently. A method for gasifying tire chips, which comprises continuously or intermittently supplying a mixture of air and water vapor from below to take out a fuel gas mainly composed of carbonization gas and water gas. 2. The gasification method according to claim 1, wherein the carbonaceous solid fuel has a particle size of 5 mm or more.