Patent Application
20190367826
The present disclosure relates to a composite gasification apparatus for coal gasification, and specifically, to a gasification furnace for sequentially performing fluidization, pyrolysis, and gasification by a circulating fluidized bed and a pyrolysis bed of the gasification furnace. The composite gasification apparatus is used for gasification of raw coal, and belongs to the field of coal gasification equipment technologies.
With the rapid development of industrial economies, coal combustion has become an indispensable path for obtaining thermal energy in industrial production processes. However, direct coal combustion pollutes the environment heavily. Therefore, in recent years, Chinese government has issued a large number of guidelines that prohibit obtaining thermal energy from direct coal burning. Instead, raw coal is required to be converted to clean and pollution-free coal gas for combustion to obtain thermal energy. Therefore, various gasification furnaces, such as fixed bed gasification furnaces and circulating fluidized bed gasification furnaces, have been designed for converting raw coal to coal gas, which helps to reduce pollution to the environment caused by combustion to some extent. However, it has been found that each type of the gasification furnaces, or gasifiers, has its own advantages and disadvantages. For example, a fixed bed gasifier generally has a high coal conversion rate and a high thermal efficiency, but the coal gas generated by a fixed bed gasifier contains a large amount of contaminant or pollutant such as tar. In contrast, a circulating fluidized bed gasifier can produce clean coal gas that does not contain contaminant or pollutant such as tar, but it generally has disadvantages including a low thermal utilization efficiency of raw coal, as well as coal slag that contains a large amount of semicoke. The coal slag would need to be transported to a burning environment with low requirements for re-burning (e.g., used as raw material burnt in a thermal power plant). Consequently, the thermal utilization rate of the raw coal is decreased. Moreover, various costs such as transportation and/or manpower are increased. Therefore, there is a need for a coal gasification device that is capable of ensuring a high efficiency of converting raw coal to coal gas while obtaining clean coal gas at the same time.
This section is for the purpose of summarizing some aspects of the present disclosure and to briefly introduce some preferred embodiments. Simplifications or omissions in this section as well as in the abstract or the title of this description may be made to avoid obscuring the purpose of this section, the abstract and the title. Such simplifications or omissions are not intended to limit the scope of the present disclosure.
An objective of the present disclosure is to provide a method for implementing gasification by a combining circulating fluidized bed and a pyrolysis bed. In the method, combustion and gasification are performed by combining a circulating fluidized bed gasification furnace and a pyrolysis bed gasification furnace, thereby improving conversion efficiency of raw coal, and eliminating primary pollutants in coal gas.
The objective of the present disclosure is further to provide an apparatus for implementing gasification by combining a circulating fluidized bed and a pyrolysis bed. The apparatus performs fluidized gasification and pyrolysis gasification on raw coal sequentially, and is a device configured to produce clean coal gas with the high conversion efficiency.
To achieve the foregoing objective, according to one aspect of the present disclosure, an apparatus for implementing gasification by combining a circulating fluidized bed and a pyrolysis bed is provided. The apparatus includes a circulating fluidized bed gasification furnace, a cyclone separator, a deposition chamber, a conveyor, a high-temperature air pipe, a vapor pipe, an oxygen pipe, a fly ash pipe, a slag pan, and a gas distribution body. The circulating fluidized bed gasification furnace is configured to receive raw coal through a coal conveying pipe, an upper portion of the circulating fluidized bed gasification furnace is in communication with an upper portion of the cyclone separator via a first coal gas pipe. A top portion of the cyclone separator is in communication with a top portion of the deposition chamber via a second coal gas pipe. The upper portion of the circulating fluidized bed gasification furnace forms a gasification furnace chamber. A gas distributor is disposed in a middle portion of the circulating fluidized bed gasification furnace, and a lower portion of the circulating fluidized bed gasification furnace forms a first mixture gas distribution chamber. The cyclone separator comprise a central cylinder disposed within the upper portion of the cyclone separator. A bottom portion of the cyclone separator is floatingly disposed on the slag pan, and a watertight seal is disposed between the slag pan and the bottom portion of the cyclone separator. The gas distribution body is disposed in the bottom portion of the cyclone separator and located on the slag pan. A second mixture gas distribution chamber is formed between the slag pan and a lower portion of the gas distribution body. A lower portion of an inner cavity of the cyclone separator, the gas distribution body, and the second mixture gas distribution chamber located below the gas distribution body collectively form a pyrolysis bed gasification furnace. An oblique guide plate is disposed in an upper portion of the deposition chamber. The conveyor is disposed under a bottom portion of the deposition chamber, and is connected to the fly ash pipe. The high-temperature air pipe, the vapor pipe, the oxygen pipe, and the fly ash pipe are in communication with the first mixture gas distribution chamber formed by the lower portion of the circulating fluidized bed gasification furnace. The high-temperature air pipe, the vapor pipe, and the oxygen pipe are in communication with the second mixture gas distribution chamber located below the lower portion of the gas distribution body.
In a further embodiment, the oblique guide plate is obliquely disposed in the deposition chamber.
In a further embodiment, the gas distribution body is cone-shaped.
In a further embodiment, a top portion of the central cylinder of the cyclone separator is in communication with the top portion of the deposition chamber via the second coal gas pipe.
According to another aspect of the present disclosure, a method for implementing gasification by combining a circulating fluidized bed and a pyrolysis bed is provided. The method includes: combusting, fluidizing, and gasifying raw coal in an environment having a temperature between 900° C. and 1200° C. in a circulating fluidized bed gasification furnace preliminarily to generate coal gas, carbon-containing fly ash, and semicoke; feeding the carbon-containing fly ash, the semicoke and the coal gas into a cyclone separator, wherein the semicoke is separated; introducing the separated semicoke into a pyrolysis bed gasification furnace; introducing a gasification agent into a bottom portion of the pyrolysis bed gasification furnace; combusting the separated semicoke in the pyrolysis bed gasification furnace for further pyrolysis and gasification; introducing coal gas generated in the pyrolysis bed gasification furnace, the coal gas generated in the circulating fluidized bed gasification furnace, and the carbon-containing fly ash generated in the circulating fluidized bed gasification furnace through a central cylinder of the cyclone separator; discharging coal slag into a slag pan at the bottom portion of the pyrolysis bed gasification furnace; introducing the carbon-containing fly ash deposited in the deposition chamber into a first mixture gas distribution chamber located at a bottom portion of the circulating fluidized bed gasification furnace via a conveyor and a fly ash pipe; introducing the carbon-containing fly ash into the circulating fluidized bed gasification furnace to heat along with the gasification agent for circulating gasification and combustion.
In a further embodiment, the gasification agent introduced into the bottom portion of the pyrolysis bed gasification furnace is a mixed gas of air and water vapor, and the semicoke are combusted and pyrolyzed in the pyrolysis bed gasification furnace.
In a further embodiment, the gasification agent introduced into the bottom portion of the circulating fluidized bed gasification furnace is a mixed gas of air, water vapor and oxygen, and the raw coal are combusted and pyrolyzed in the circulating fluidized bed gasification furnace.
In a further embodiment, the gasification agent introduced into the bottom portion of the pyrolysis bed gasification furnace is a mixed gas of air, water vapor and oxygen, and the semicoke are combusted and pyrolyzed in the pyrolysis bed gasification furnace.
According to yet another aspect of the present disclosure, an apparatus for implementing gasification by combining a circulating fluidized bed and a pyrolysis bed is provided. The apparatus includes a circulating fluidized bed gasification furnace and a pyrolysis bed gasification furnace. Specifically, the circulating fluidized bed gasification furnace comprises a coal conveying pipe capable of conveying raw coal to the circulating fluidized bed gasification furnace. The raw coal is fluidizedly combusted and pyrolyzed in the circulating fluidized bed gasification furnace to generate coal gas, carbon-containing fly ash, and semicoke. An upper portion of the pyrolysis bed gasification furnace is in communication with an upper portion of the circulating fluidized bed gasification furnace via a coal gas pipe, and a coal gas outlet is disposed on the upper portion of the pyrolysis bed gasification furnace. The coal gas, the carbon-containing fly ash, and the semicoke generated in the circulating fluidized bed gasification furnace are configured to enter the pyrolysis bed gasification furnace via the coal gas pipe, wherein the semicoke is configured to drop to a bottom portion of the pyrolysis bed gasification furnace. A gasification agent is introduced into the bottom portion of the pyrolysis bed gasification furnace, and the semicoke is combusted in the pyrolysis bed gasification furnace to be further pyrolyzed and gasified to generate coal gas. In addition, coal slag is discharged to a slag pan located at the bottom portion of the pyrolysis bed gasification furnace.
In a further embodiment, the upper portion of the circulating fluidized bed gasification furnace forms a gasification furnace chamber. A gas distributor is disposed in a middle portion of the circulating fluidized bed gasification furnace, and a lower portion of the circulating fluidized bed gasification furnace forms a first mixture gas distribution chamber. The gasification agent is introduced into the first mixture gas distribution chamber. Moreover, a bottom portion of a furnace body of the pyrolysis bed gasification furnace is floatingly disposed on the slag pan, and a watertight seal is disposed between the slag pan and the bottom portion of the furnace body of the pyrolysis bed gasification furnace. A gas distribution body is disposed in the bottom portion of the furnace body of the pyrolysis bed gasification furnace and located on the slag pan. A second mixture gas distribution chamber is formed between the slag pan and a lower portion of the gas distribution body. The gasification agent is also introduced into the second mixture gas distribution chamber.
In a further embodiment, the apparatus further includes a deposition chamber, a conveyor, a high-temperature air pipe, a vapor pipe, an oxygen pipe, and a fly ash pipe. A top portion of the pyrolysis bed gasification furnace is in communication with a top portion of the deposition chamber via a coal gas pipe. An oblique guide plate is disposed in an upper portion of the deposition chamber. The conveyor is disposed below a bottom portion of the deposition chamber and connected to the fly ash pipe. The high-temperature air pipe, the vapor pipe, the oxygen pipe, and the fly ash pipe are in communication with the first mixture gas distribution chamber, whereas the high-temperature air pipe, the vapor pipe, and the oxygen pipe are in communication with the second mixture gas distribution chamber.
It is to be noted that the circulating fluidized bed gasification furnace has an advantage of generating no tar or other pollutants during gasification. Furthermore, the fixed gasification bed has an advantage of high raw coal gasification rate. Taking both advantages, each of the composite gasification apparatuses of the present disclosure combines a circulating fluidized bed gasification furnace and a pyrolysis bed gasification furnace are combined into one coal gasification device. The combined coal gasification device not only produces no pollutants such as tar, but also achieves high conversion rate of raw coal to coal gas. Consequently, the apparatuses according to the present disclosure achieve a high raw coal gasification rate while producing no pollutants, such as tar, during gasification, making them suitable for equipment of either a large, medium, or small gasification capacity, or equipment having a large dynamic range of gas yield per unit time.
The accompany drawings are schematic structural diagrams of embodiments of the present disclosure.
The detailed description of the present disclosure is presented largely in terms of procedures, steps, logic blocks, processing, or other symbolic representations that directly or indirectly resemble the operations of devices or systems contemplated in the present disclosure. These descriptions and representations are typically used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.
Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be comprised in at least one embodiment of the present disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams or the use of sequence numbers representing one or more embodiments of the present disclosure do not inherently indicate any particular order nor imply any limitations in the present disclosure.
To make the foregoing objectives, features, and advantages of the present disclosure more comprehensible, the present disclosure is described in further detail with reference to the accompanying drawings and specific implementations.
When the composite gasification apparatus of
As shown in
In one preferred embodiment, the upper portion of the circulating fluidized bed gasification furnace 2 forms a gasification furnace chamber; a gas distributor 201 is disposed in a middle portion of the circulating fluidized bed gasification furnace 2; a lower portion of the circulating fluidized bed gasification furnace 2 forms a first mixture gas distribution chamber 202; the gasification agent is introduced into the first mixture gas distribution chamber 202. A bottom portion of a furnace body 113 of the pyrolysis bed gasification furnace 11 is floatingly disposed on a slag pan 302. A watertight seal is disposed between the slag pan 302 and the bottom portion of the furnace body 113 of the pyrolysis bed gasification furnace 11. A gas distribution body 301 is disposed in the bottom portion of the furnace body 113 of the pyrolysis bed gasification furnace 11 and located on the slag pan 302. A second mixture gas distribution chamber 303 is formed between the slag pan 302 and a lower portion of the gas distribution body 301. The gasification agent is introduced into the second mixture gas distribution chamber 303. In one preferred embodiment, the pyrolysis bed gasification furnace 11 includes an oblique guide plate 114 disposed in the upper portion of the pyrolysis bed gasification furnace 11. The oblique guide plate 114 is configured to guide or otherwise direct the coal gas, the carbon-containing fly ash, and the semicoke that enter the pyrolysis bed gasification furnace 11 through the coal gas pipe to travel downward, so that the semicoke may drop to the bottom portion of the pyrolysis bed gasification furnace 11 more easily.
In one more preferred embodiment, the apparatus further includes a deposition chamber, a conveyor, a high-temperature air pipe, a vapor pipe, an oxygen pipe, and a fly ash pipe. A top portion of the pyrolysis bed gasification furnace 11 is in communication with a top portion of the deposition chamber via a coal gas pipe. An oblique guide plate is disposed in an upper portion of the deposition chamber, and the conveyor is disposed below a bottom portion of the deposition chamber. The conveyor is connected to the fly ash pipe. The high-temperature air pipe, the vapor pipe, the oxygen pipe, and the fly ash pipe are in communication with the first mixture gas distribution chamber 202. The high-temperature air pipe, the vapor pipe, and the oxygen pipe are in communication with the second mixture gas distribution chamber 303.
The foregoing descriptions have fully disclosed the specific implementations of the present disclosure. It should be noted that any change made to the specific implementations of the present disclosure by a person skilled in the art does not depart from the scope of the claims of the present disclosure. Correspondingly, the scope of the claims of the present disclosure is not limited to the specific implementations.
The herein-described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable”, to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components.
Further, with respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
Moreover, it will be understood by those skilled in the art that, in general, terms used herein, and especially in the appended claims, e.g., bodies of the appended claims, are generally intended as “open” terms, e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to implementations containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an,” e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more;” the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number, e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations. Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention, e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
From the foregoing, it will be appreciated that various implementations of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various implementations disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017100480623 | Jan 2017 | CN | national |
This application is the U.S. national stage application of International Application No. PCT/CN2017/088047, filed on Jun. 13, 2017, which claims the priority benefit of China Patent Application No. 2017100480623, filed on Jan. 23, 2017. The above-identified patent applications are hereby incorporated by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2017/088047 | 6/13/2017 | WO | 00 |
