WO2017154679A1

WO2017154679A1 - Method and device for separating solids from fluidized layer

Info

Publication number: WO2017154679A1
Application number: PCT/JP2017/007884
Authority: WO
Inventors: 斉井上
Original assignee: 特定非営利活動法人Ａｐｅｘ
Priority date: 2016-03-07
Filing date: 2017-02-28
Publication date: 2017-09-14
Also published as: JP6914539B2; JPWO2017154679A1

Abstract

The present invention pertains to a feature of a fluidized layer, and in particular, provides a method and device for efficiently separating solids from a bubble fluidized layer. Specifically, the solids separation method according to the present invention separates relatively coarse solids present in a fluidized layer from a fluid medium and continuously carries the solids out to the exterior of a fluidized layer device, wherein the solid separation method is characterized in that a part of a belt-shaped conveyance means is installed in or adjacent to the fluidized layer and is continuously circulated to continuously carry the solids out to the exterior of the fluidized layer device, the belt-shaped transportation means having: a capturing belt having gaps that are smaller than the diameter of the solids and larger than the diameter of the substance constituting the fluid medium of the fluidized layer, the size of the gaps enabling the fluid medium to pass and the solids to be selectively captured; or a collector having similarly sized gaps.

Description

Method and apparatus for separating solids from a fluidized bed

The present invention relates to a method and apparatus for effectively separating solids from a fluidized bed.

More specifically, the present invention provides a method and apparatus for separating solids present in a fluidized bed and having a particle size larger than that of a fluidized medium and having a smaller particle density. According to the method and apparatus of the present invention, for example, in a biomass fluidized-bed gasifier, char produced as a by-product with gas is separated from the fluidized medium and extracted, and then reduced to produce renewable energy. It is possible to suppress the increase in carbon dioxide concentration in the atmosphere by carbon fixation and to achieve sustainable production of biomass. In addition, the present invention can be applied to other uses that remove solids having a particle size larger than that of the fluid medium and a smaller particle density.

In recent years, it has become a global practice to develop renewable energy technology and widely disseminate it in order to prevent global warming and avoid depletion of finite fossil fuel resources such as coal and oil. It is an urgent issue. Among natural energies, biomass energy, in particular, is positioned as the top of natural energy because it has a large abundance and is relatively easy to convert to fuel.

Biomass energy utilization technologies include direct combustion, thermochemical conversion technology, and biochemical conversion technology, but direct combustion has limited efficiency, especially for small-scale processes. There is a problem that only limited biomass such as starch can be used as a raw material. On the other hand, according to thermochemical conversion, biomass including cellulosic compounds can be used as a whole, and high-efficiency energy can be used even on a small scale.

However, in the existing thermochemical conversion technology, non-catalytic gasification generates tar at low temperatures, so it is necessary to increase the temperature, and an increase in the thermal burden on the equipment material and a decrease in thermal efficiency cannot be avoided. . In addition, in the method of partial combustion using air as part or all of the gasifying agent, the generated gas becomes a low calorific value / low quality gas. In order to avoid this, it has been proposed to use an externally heated gasifier with only the gasifying agent as steam. However, such an externally heated gasifier has low thermal efficiency and heat transfer problems. There are also restrictions on scale and structure. When a catalyst is used, although the gasification temperature can be lowered, the catalyst is generally expensive, and there is a problem that it is quickly deteriorated or deactivated.

In order to solve these problems, the present inventors have already made use of an organic material containing biomass as a catalyst and / or a heat medium function in a gasification reaction zone in a temperature rising condition and in the presence of a gasifying agent. A technology for converting the organic raw material into a useful gas for producing a gas / liquid fuel by fluid contact with a gasification accelerator made of clay having a catalyst has been developed (Patent Document 1: Japanese Patent No. 4259777). . According to this technique, it is possible to efficiently gasify an organic material while suppressing tar formation under a relatively mild temperature condition of 400 ° C. to 750 ° C.

Furthermore, the inventor of the present invention uses, in such a technique, a material having a high heat transfer property such as a metal as a partition wall between the gasification reaction zone and the regeneration zone, so that radiation, conduction, and conduction from the regeneration zone to the gasification reaction zone can be achieved. Developed a biomass gasification method that conducts heat transfer by convection and can reduce the temperature of the regeneration zone compared to the case without heat transfer and enhance the automatic temperature control function of the device (Patent Document 2: Japanese Patent No. 4549918).

Generally, when biomass is gasified, if the size of the raw material biomass is large, there is a problem that the rate of temperature rise inside the biomass decreases and tar generation increases. Prior to this, the biomass must be finely crushed.

In this regard, in the method of gasifying a clay particle having a catalytic function and / or a heat medium function by fluid contact with a gasification accelerator according to the above-described invention of the present inventors, the biomass into which clay is charged is surrounded. Thus, since the generated tar is adsorbed and decomposed, there is an advantage that unpulverized biomass can be input as it is. In addition, since the shear stress of the clay particles used as a catalyst in the present invention is small, a large char having a shape almost the same as that of the input biomass can be obtained.

¡If this char is separated from the fluidized bed, extracted and reduced in soil, the carbon that causes global warming will be fixed. Char is rich in minerals derived from biomass, promotes the growth of useful microorganisms such as chisso-fixing bacteria, and improves the water permeability and water retention of the soil. It will also help the growth. In other words, along with the production of renewable energy, carbon fixation and sustainable production of plants will be promoted. Charcoal obtained from the traditional charcoal baking process has also been used for soil improvement from the past, but in such traditional charcoal burning, the energy (useful gas) generated when generating charcoal is discarded. . Therefore, in this respect as well, the above-described prior inventions can utilize the generated energy (useful gas) for power generation, and use the biomass resources.

Thus, in order to effectively use char as a by-product of biomass energy utilization, a method of extracting char that is a solid from a fluidized bed is required. Conventional methods for extracting solids from a fluidized bed include Japanese Patent Application Laid-Open No. 2004-138378 “Noncombustible Material Extraction System and Fluidized Bed Furnace System” (Patent Document 3) and Japanese Patent Application Laid-Open No. 08-028842 “Noncombustible in Fluidized Bed Waste Incinerator”. Material discharge method and apparatus "(Patent Document 4) and the like have been proposed. However, all of these technologies are intended to extract solids that sink into the furnace bottom of the fluidized bed and have a particle density higher than that of the fluidized medium. . No technology has yet been developed to effectively separate solids that are relatively small in particle density and float above the dense phase of the bubble fluidized bed, such as char derived from biomass.

Registered Patent No. 4259777 Patent No. 4549918 JP 2004-138378 A Japanese Patent Application Laid-Open No. 08-028842

The present invention is for solving the above-mentioned technical problem, and in particular, when the diameter of the substance constituting the fluidized medium is different from the diameter of the solid matter in the fluidized bed to be separated, the bubble fluidized bed And a method and apparatus for effectively separating and recovering the solid matter.

In order to solve the technical problem described above, the solids recovery method according to the present invention separates relatively coarse solids present in the fluidized bed from the fluidized medium and continuously carries them out of the fluidized bed apparatus. The gap is smaller than the diameter of the solid matter and larger than the diameter of the substance constituting the fluidized medium of the fluidized bed, and has a diameter that allows the fluidized medium to pass through and selectively capture the solid matter. A part of the belt-like conveying means having a trapping zone having a large number of gaps is installed in the fluidized bed apparatus and continuously circulated so that the solid matter is continuously separated and carried out of the fluidized bed apparatus. It is characterized by that. Here, the trapping band refers to a strip-shaped mechanism that traps the solid matter, and can be provided integrally with the transport surface of the strip-shaped transport means.

In a preferred embodiment of the present invention, the fluidized bed is a bubble fluidized bed.

Furthermore, in a preferred aspect of the present invention, it is preferable that the belt-like conveying means is a belt-like conveyor, and the belt-like conveying means moves horizontally near the upper end of the dense phase portion of the fluidized bed for a certain interval. .

Further, in the present invention, in the fluidized bed, the solid matter is obtained by making a difference between the superficial velocity of the fluidized bed at the position where the belt-like conveying means is arranged and the superficial velocity of the other fluidized bed portions. Is preferably guided to the capture surface of the belt-like transport means.

In another preferred embodiment of the present invention, the belt-like transport means may include a collector for separating and collecting the solid matter instead of the trapping zone. The collector includes a plurality of blades, and the distance between the blades is smaller than the diameter of the solid material and larger than the diameter of the substance forming the fluidized medium of the fluidized bed. It is preferable that a plurality of the collectors are provided on the belt-like conveying means in such a manner that solids can be captured. In the present invention, the solid matter induced in the vicinity of the fluidized bed at the position where the belt-like transport means is disposed is captured by the collector, and the trapped solid matter is caused by the circulation movement of the belt-like transport means and the collector. It is preferable that the fluidized bed is scraped up and then continuously separated and carried out of the fluidized bed apparatus.

Furthermore, in a preferred embodiment of the present invention, the above method is introduced into a fluidized bed gasification process of biomass.

In the present invention, the solid matter to be separated usually consists of biomass-derived char.

On the other hand, an apparatus according to the present invention is an apparatus for separating a relatively coarse solid present in a fluidized bed from a fluidized medium and continuously carrying it out of the fluidized bed apparatus. A belt-like conveying means having a trapping zone having a plurality of gaps smaller than the diameter of the substance forming the fluidized medium of the fluidized bed and having a diameter through which the fluidized medium passes and the solid matter is selectively captured And a power means for introducing a part of the belt-like transport means into the fluidized bed apparatus and continuously circulating it, and fluidizing the solid matter selectively captured by the belt-like transport means It is characterized by being continuously separated and carried out of the apparatus.

In the apparatus according to the present invention, the fluidized bed is preferably a bubble fluidized bed.

Furthermore, in a preferred aspect of the apparatus according to the present invention, the belt-like transport means comprises a belt-like conveyor, and the belt-like transport means moves horizontally near the upper end of the dense phase portion of the fluidized bed for a certain interval. It is preferable to be provided. Moreover, a chain conveyor can be used as an example of such a belt-shaped conveyor.

Furthermore, the apparatus according to the present invention further comprises an apparatus for making a difference between the superficial velocity of the fluidized bed at the position where the belt-like transport means is disposed and the superficial velocity of the other fluidized bed portions in the fluidized bed. However, it is preferable that the solid material is guided to the capturing surface of the belt-like transport unit.

Further, in another preferred aspect of the apparatus according to the present invention, the belt-like transport means may include a collector for separating and collecting the solid matter instead of the trapping zone. The collector includes a plurality of blades, and the distance between the blades is smaller than the diameter of the solid material and larger than the diameter of the substance forming the fluidized medium of the fluidized bed. It is preferable that a plurality of the collectors are provided on the belt-like conveying means in such a manner that solids can be captured. In the present invention, the solid matter induced in the vicinity of the fluidized bed at the position where the belt-like conveying means is arranged is captured by the collector, and is scraped up from the fluidized bed with the circulation movement of the belt-like conveying means and the collector, Next, it is preferable to continuously separate and carry out the fluidized bed apparatus.

Moreover, it is preferable that the solid matter recovery apparatus according to the present invention is introduced or incorporated into a fluidized bed gasification apparatus for biomass.

The solid matter to be separated by the apparatus according to the present invention is usually made of biomass-derived char.

The above-described solid material recovery technology according to the present invention can be suitably applied to, for example, biomass gasification technology already developed by the present inventors. For example, in the biomass gasification technology described in Patent Document 1 (Patent No. 4259777) described above, an organic material containing biomass is used in a gasification reaction zone in the presence of a gasifying agent under temperature rising conditions. The organic material is converted into a useful gas for the production of gas / liquid fuel by fluid contact with a gasification accelerator composed of clay having a catalytic function and / or a heat medium function. According to this technology, Under a relatively mild temperature condition of 400 ° C. to 750 ° C., the organic material can be efficiently gasified without generating tar.

Further, in the method described in Patent Document 2 (Japanese Patent No. 4549918), a material having a high heat transfer property such as a metal is used as a partition wall between the gasification reaction zone and the regeneration zone, so that the regeneration zone is changed to the gasification reaction zone. The heat transfer by radiation, conduction and convection is performed, the temperature of the regeneration zone can be reduced as compared with the case where there is no heat transfer, and the automatic temperature control function of the apparatus can be enhanced.

The solids recovery technology according to the present invention can be suitably applied to the biomass gasification technology described above, but is not limited thereto, and the biomass gas generated as a by-product of the solids to be separated is not limited thereto. It can be widely applied to the technology.

It is a typical top view of the solid separation device by the present invention. The white arrow indicates the flow of the fluid medium and the solid matter to be separated in the fluidized bed. It is a typical elevational view of the fluidized bed portion of the solid matter separation device according to the present invention. Open arrows indicate the flow of the fluidized medium in the fluidized bed, and solid arrows indicate the flow of the gasifying agent before being introduced into the fluidized bed. It is a typical side view of the whole solid substance separator by this invention. It is a typical top view of the solid substance separation device by another embodiment of the present invention. The white arrow indicates the flow of the fluid medium and the solid matter to be separated in the fluidized bed. It is a typical elevation view of a fluidized bed portion of a solids separation device according to another embodiment of the present invention. Open arrows indicate the flow of the fluidized medium in the fluidized bed, and solid arrows indicate the flow of the gasifying agent before being introduced into the fluidized bed. It is a typical side view of the whole solid-state separator by another embodiment of this invention.

Hereinafter, exemplary embodiments for carrying out the present invention will be described with reference to the accompanying drawings. The drawings are merely examples, and the scope of the claims of the present invention is not limited to these forms or embodiments.

According to the present invention, solids present in the bubble fluidized bed can be carried out of the fluidized bed while being separated from the fluidized medium. As a specific example, as shown in FIGS. 1 and 2, a gas fluidization zone 3 and a regeneration zone 2 are provided, and a bubble fluidized bed is formed using a clay having a catalytic function and / or a heat medium function as a gasification accelerator between them. A gas in which an organic substance containing biomass 6 is introduced into the gasification reaction zone 3 and gasified in the presence of a gasifying agent and a gasification accelerator, and adsorption by-products such as carbon are deposited on the surface. The regeneration accelerator 2 is led to the regeneration zone 2, and the adsorption by-products attached to the gasification accelerator in the regeneration zone 2 are removed by combustion or by partial combustion and carbonaceous gasification reaction, and thus regenerated. In the biomass gasification apparatus 1 of the system in which the gasification accelerator in the heated state is recirculated to the gasification reaction zone 3, it is adjacent to the vicinity of the upper end of a part of the dense fluidized bed in the gasification reaction zone 3, Fluid medium The belt-shaped conveyor 4 having a large number of gaps smaller than the diameter of the separation target char and smaller than the diameter of the separation target char and disposed horizontally, and solids transferred by the conveyor outside the fluidized bed A separation device for the char 7 comprising a discharge device for discharging is installed.

In the biomass fluidized bed gasifier using clay as a gasification accelerator, the clay having the action of adsorbing and decomposing tar surrounds the biomass charged into the gasification reaction zone. Since the shear stress of clay is small, the char 7 produced from large-diameter biomass is also large-diameter. Therefore, the fluid medium and the char 7 can be separated by the difference in diameter by the conveyor 4 installed as described above.

As shown in FIG. 3, the separated char 7 is moved horizontally to a position not accompanied by scattering of particles from the fluidized bed by the continuous movement of the conveyor 4, and then installed in the vertical direction. The chute 12 drops and is discharged to the outside through a blocking mechanism with the outside such as the double damper 13. On the other hand, the scattered particles can be returned to the original fluidized bed by providing

buffer zones

10a and 10b in which the bottom plate is inclined toward the fluidized bed at a position near the fluidized bed where the particles are scattered.

In a preferred embodiment of the present invention, the lower belt speed of the belt-like conveyor 4 is set lower than that of the adjacent fluidized bed 8 so that the belt-like conveyor as shown in FIG. 4 can generate a circulating flow that pushes solids present in the fluidized bed 8 adjacent to the belt 4 onto the trapping belt of the belt-like conveyor 4. By generating such a circulating flow, the probability that the solid matter is captured by the belt-like conveyor 4 is increased, and the solid matter can be more efficiently separated.

In another preferred embodiment of the present invention, for example, the bottom plate of the fluidized bed at the bottom of the belt-like conveyor 4 is adjacent to the belt-like conveying means 4 by inclining it deeper toward the adjacent fluidized bed 8. It is possible to make it easier to generate a circulating flow that pushes the solid matter (char 7) present in the fluidized bed 8 onto the trapping zone of the belt-like conveying means 4. By generating the circulating flow more effectively in this way, there is a high possibility that the solid material 7 will be guided on the trapping surface of the belt-like transport means 4, and the solid material can be more efficiently separated. .

Further, in another preferred embodiment of the present invention, the driving unit of the belt-like transport unit 4 can be disposed at a position isolated from the fluidized bed 8. By disposing the drive unit in a place away from the fluidized bed in this way, the drive unit is not easily affected by heat and moisture, the risk of failure can be reduced, and the durability of the device itself can be improved. This is also advantageous.

In another preferred embodiment of the present invention, as shown in FIGS. 4 to 6, the belt-like transport means 4 can be provided with a collector 14 for separating and capturing solid matter instead of the trapping band. . The collector 14 includes a plurality of blades, and the distance between the blades is smaller than the diameter of the solid matter and larger than the diameter of the substance forming the fluidized medium of the fluidized bed. It is preferable that a plurality of the collectors 14 are provided in such a manner that the solid material can be captured by the belt-like conveying means. As a result, the solid material induced in the vicinity of the fluidized bed at the position where the belt-like conveying means is disposed is captured by the collector, and is scraped up from the fluidized bed by the circulation movement of the belt-like conveying means and the collector, and then the fluidized bed. It can be continuously separated and carried out of the apparatus.

Also, in other embodiments of the present invention, some or all of the above-described embodiments can be combined.

Examples in which solids are separated by the solids separator according to the present invention will be specifically described below.

Example of generation of large diameter char In a biomass gasification apparatus 1 having a gasification reaction zone 3 and a regeneration zone 2 in which a deformed ellipse having a length of 2.1 m, a width of 1.6 m, and a height of 3 m is divided by a partition wall, Gasification was performed using 20 to 45 cm of biomass 6, which was obtained by dividing the production oil palm empty bunch into a quarter. As the clay catalyst to be added, Indonesian clay having an average particle diameter of 450 μm was used. The main operating conditions are an air ratio of 0.1, a gasifier temperature of 690 ° C., a steam / biomass ratio of 0.82, and a biomass input rate of 252 kg (wet weight) / hour. At this time, the gas of higher heating value 8.29MJ / Nm ³ is, 196 nm ³ / time obtained, the cold gas efficiency is 43.2%, the tar concentration in the product gas was 136 mg / Nm ^3. At this time, a char 7 containing the carbon content of 20 to 25% of the carbon content in the input biomass and maintaining the outer shape of the input empty cell piece was obtained.

Separation of solids from fluid medium (Example 1)
In the internal circulation type bubbling fluidized bed cold model in which the gasification reaction zone 3 and the regeneration zone 2 are separated from each other by the partition, the solids are separated as shown in FIGS. 1, 2 and 3 adjacent to the gasification reaction zone 3. -A belt-shaped conveyor for recovery (equipped with a trapping band having a number of diamond-shaped gaps of 2 cm in the horizontal direction and 3.5 cm in the vertical direction) was installed. This apparatus is filled with clay particles with an average particle diameter of 200 μm, and the fluidized bed 8 has a superficial velocity of Uo-Umf = 0.15 m / s and the lower part of the belt-shaped conveyor is 0.06 m / s (2 Umf). The air was introduced and fluidized. There, when charcoal with a diameter of 3 cm and a length of 5-10 cm was introduced and operated, over 90% of the charcoal was discharged out of the system by a belt-shaped conveyor. On the other hand, when charcoal was pulverized and charged as a lump having a major axis of 1 cm or less, no charcoal was discharged.

(Example 2)
In the internal circulation type bubbling fluidized bed cold model in which the gasification reaction zone 3 and the regeneration zone 2 exist with a partition wall therebetween, adjacent to the gasification reaction zone 3, as shown in FIGS. -A chain conveyor 4 with a collector for collection (interval between collector blades: 1.5 cm) was installed. Viscosity particles with an average particle diameter of 350 μm are packed into this device, and air is supplied so that the fluidized bed Uo-Umf = 0.10 m / s and the lower part of the conveyor have an empty speed of 0.15 m / s (1.5 Umf). It was introduced and allowed to flow. There, when charcoal with a diameter of 3 cm and a length of 5-10 cm was introduced and operated, over 90% of the charcoal was discharged out of the system by the conveyor. On the other hand, when charcoal was pulverized and charged as a lump having a major axis of 1 cm or less, no charcoal was discharged.

DESCRIPTION OF SYMBOLS 1 Biomass gasifier 2 Regeneration zone 3 Gasification reaction zone 4 Belt-shaped conveyor 5 Fluid medium 6 Biomass 7 Char 8 Fluidized bed 9 Gasifying agent

10a Buffer zone

10b Buffer zone 11 Drive part 12 Chute 13 Double damper 14 Collector

Claims

A method of separating a relatively coarse solid present in a fluidized bed from a fluidized medium and continuously carrying it out of a fluidized bed apparatus, wherein the substance forming the fluidized medium of the fluidized bed is smaller than the diameter of the solids A part of the belt-like transport means having a gap larger than the diameter of the trapping zone having a large number of gaps having a diameter through which the fluid medium passes and the solid matter is selectively trapped is installed in the fluidized bed apparatus. The solid material is continuously circulated and separated from the fluidized bed apparatus so as to be carried out.
Instead of the trapping belt, the strip-shaped transport means is provided with a collector for separating and trapping solid matter, and the distance between the blades of the collector is smaller than the diameter of the solid matter and the diameter of the substance forming the fluidized medium of the fluidized bed. The method of claim 1, wherein the method is large.
The method according to claim 1 or 2, wherein the fluidized bed is a bubble fluidized bed.
The method according to any one of claims 1 to 3, wherein the belt-like transport means is a chain conveyor.
The method according to any one of claims 1 to 4, wherein the belt-like conveying means moves horizontally in the vicinity of the upper end of the dense phase portion of the bubble fluidized bed or the fluidized bed adjacent thereto.
In the fluidized bed apparatus, the solid matter is separated from the belt-like conveying means by differentiating the superficial velocity of the fluidized bed at the position where the belt-like conveying means is arranged and the superficial velocity of the other fluidized bed part. The method according to any one of claims 1 to 5, wherein the method is guided on a capture surface.
The method according to any one of claims 1 to 6, which is introduced into a fluidized bed gasification process of biomass.
The method according to claim 7, wherein the solid matter to be separated is char derived from biomass.
An apparatus for separating relatively coarse solids present in a fluidized bed from a fluidized medium and continuously carrying out of the fluidized bed apparatus,
A trapping zone having a number of gaps smaller than the diameter of the solid matter and larger than the diameter of the substance forming the fluidized medium of the fluidized bed, wherein the fluidized medium passes therethrough and the solid matter is selectively captured. A belt-shaped conveying means having
A power means for introducing a part of the belt-like conveying means into the fluidized bed apparatus and continuously circulating it;
The apparatus is characterized in that the solid matter selectively captured by the belt-like conveying means is continuously separated and carried out of the fluidized bed apparatus.
The belt-like conveying means includes a collector that separates and captures solid matter instead of the trapping zone, and the interval between the collector blades is smaller than the diameter of the solid matter and is smaller than the diameter of the substance forming the fluidized medium of the fluidized bed. The apparatus of claim 9, wherein the apparatus is large.
The apparatus according to claim 10, wherein the fluidized bed is a bubble fluidized bed.
The apparatus according to any one of claims 9 to 11, wherein the belt-shaped transport means is a chain conveyor.
The apparatus according to any one of claims 9 to 12, wherein the belt-like transport means is provided so as to move horizontally in a certain section near the upper end of the dense phase portion of the fluidized bed.
In the fluidized bed, the apparatus further comprises a device that makes a difference between the superficial velocity of the fluidized bed at the position where the belt-like transport means is arranged and the superficial velocity of the other fluidized-bed portions, and the solid matter is transported in the beltlike manner. A device according to any one of claims 9 to 13, adapted to be guided on a capture surface of the means.
The apparatus according to any one of claims 9 to 14, which is introduced into a fluidized bed gasification apparatus for biomass.
The apparatus according to claim 15, wherein the solid matter to be separated is char derived from biomass.