A device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation

Abstract

The present invention belongs to the technical field related to solid fuel pyrolysis, and specifically discloses a device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation. The device includes a first reactor, which is divided into an internal reactor and an external reactor by a reactor wall. The internal reactor is used to pass solid fuel to prepare in-situ coke and generate pyrolysis gas at the same time; the lower end of the reactor wall is opened to release the pyrolysis gas generated by the internal reactor into the external reactor; the external reactor is used to fill transition metal oxides to oxidize the pyrolysis gas, thereby achieving simultaneous pyrolysis gas removal and in-situ coke preparation. In the present invention, the internal reactor serves as the place for in-situ coke preparation, and the pyrolysis gas is passed into the external reactor, and is oxidized and removed using transition metal oxides, which can reduce the emission of pollutants in the tail gas, thereby achieving simultaneous pyrolysis gas removal or in-situ coke preparation.

Description

Technical Field

[0001] The present invention belongs to the technical field related to solid fuel pyrolysis, and more specifically, relates to a device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation. Background Art

[0002] The pyrolysis of pulverized coal to produce char, the pyrolysis of biomass to produce biochar, and the pyrolysis of petroleum coke to remove volatiles release large amounts of combustible gases, such as CO, CH₄, H₂, H₂S, HCN, and NH₃, as well as tar. Safely and appropriately handling these pyrolysis byproducts to minimize potential safety hazards and environmental pollution is a pressing issue.

[0003] The conventional method for treating combustible gases is direct combustion with air. However, this method often results in low-concentration gas escape, causing environmental pollution and posing serious safety risks. Furthermore, sulfur- and nitrogen-containing substances, such as tar, require subsequent treatment, can easily clog pipelines, and removal is costly and ineffective in meeting emission standards. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides a device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation, wherein the reactor wall is used to separate the first reactor into an internal reactor and an external reactor, wherein the internal reactor serves as the place for in-situ coke preparation, and the pyrolysis gas is passed into the external reactor, and at the same time, it is oxidized and removed by using transition metal oxides to reduce the emission of pollutants in the exhaust gas, thereby simultaneously achieving pyrolysis gas removal or in-situ coke preparation.

[0005] To achieve the above-mentioned objectives, the present invention proposes a device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation, the device comprising a first reactor, which is divided into an internal reactor and an external reactor by a reactor wall, the internal reactor being used to introduce solid fuel to prepare in-situ coke while generating pyrolysis gas; a hole is opened at the lower end of the reactor wall for releasing the pyrolysis gas generated by the internal reactor into the external reactor; the external reactor is used to introduce transition metal oxides to oxidize the pyrolysis gas, thereby simultaneously achieving pyrolysis gas removal and in-situ coke preparation.

[0006] As a further preference, the device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation also includes a second reactor, the top inlet of the second reactor is connected to the bottom outlet of the external reactor to pass the deactivated transition metal oxide into the second reactor; at the same time, an air inlet is provided at the bottom of the second reactor, and the deactivated transition metal oxide is regenerated by heating in an air atmosphere.

[0007] As a further preference, a gas outlet is further provided at the top of the second reactor, and the gas outlet is connected to the gas inlet at the top of the internal reactor, for passing the oxygen-deficient air after the regeneration reaction into the internal reactor.

[0008] As further preferred, the solid fuel includes coal powder, biomass or biocoke.

[0009] As a further preference, a porous sintered plate is provided at the lower end of the reactor wall to prevent solid particles from escaping to the external reactor.

[0010] As further preferred, the transition metal oxide is iron oxide, copper oxide or manganese oxide.

[0011] As further preferred, the transition metal oxide is further doped with CaO and / or NiO.

[0012] As further preferred, the reaction temperature of the first reactor and the second reactor is 800-1000°C.

[0013] In general, the above technical solutions conceived by the present invention have the following technical advantages compared with the existing technology:

[0014] 1. The present invention provides a device for simultaneously removing pyrolysis gas and producing in-situ coke. The device utilizes a reactor wall to separate a first reactor into an internal reactor and an external reactor. The internal reactor, serving as the site for in-situ coke production, is used to pyrolyze solid fuel to obtain in-situ coke and pyrolysis gas, and the pyrolysis gas is passed into the external reactor. Considering that transition metal oxides are oxidizing to combustible gases and can relatively gently remove combustible gases while simultaneously converting tar to a gas phase, the device incorporates a transition metal oxide within the external reactor to simultaneously remove pyrolysis gas and reduce pollutant emissions in the tail gas. Furthermore, since there is no gaseous oxygen in the reaction environment, the risk of combustion or explosion during the pyrolysis gas treatment process is reduced, thereby effectively improving the stability and safety of the reaction device.

[0015] 2. In particular, the present invention also includes a second reactor to regenerate the deactivated transition metal oxide using air, effectively reducing production costs. Furthermore, the oxygen-deficient air generated during the regeneration process can be used as a carrier gas for in-situ coke production, carrying a portion of the heat to supplement the pyrolysis coking process, thereby improving energy recycling efficiency. Furthermore, it can also serve as a low-oxygen promoting gas to further enhance the pyrolysis efficiency of the solid fuel.

[0016] 3. In addition, the present invention uses iron oxide, copper oxide or manganese oxide as transition metal oxides, which can convert pyrolysis gas and tar into CO2 and H2O, and removes sulfur-containing substances and nitrogen-containing substances by loading CaO and NiO, respectively, reducing the generation of sulfur-containing gas and NOx, and further reducing environmental pollution caused by the solid fuel pyrolysis process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The invention relates to a device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation, constructed according to a preferred embodiment of the invention.

[0018] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0019] 1-first reactor, 2-second reactor, 3-reactor wall, 4-transition metal oxide, 5-solid fuel. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0021] like Figure 1 As shown, an embodiment of the present invention provides a device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation, the device comprising a first reactor 1, the first reactor 1 being divided into an internal reactor and an external reactor by a reactor wall 3, the internal reactor being designed as a structure in which solid fuel 5 (coal powder, biomass or biocoke) is added from the top and the particles move downward, so as to prepare in-situ coke while generating pyrolysis gas; a hole is opened at the lower end of the reactor wall, and a porous sintered plate is provided to release the pyrolysis gas generated in the internal reactor into the external reactor, and to prevent solid particles from escaping to the external reactor; the external reactor is designed as a structure in which fresh transition metal oxide 4 is added from the top, the particles move downward, and the pyrolysis gas moves upward, and the two are in a countercurrent form, thereby effectively improving their contact degree, so as to fully oxidize the pyrolysis gas, achieve near-zero removal of combustible gas through sufficient gas-solid contact, and simultaneously achieve conversion of tar to the gas phase, and the high-concentration CO2 and H2O generated in the external reactor are discharged through the upper end of the external reactor, and high-purity CO2 can be obtained by condensation, thereby simultaneously achieving pyrolysis gas removal and in-situ coke preparation.

[0022] Furthermore, the device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation also includes a second reactor 2, the top inlet of the second reactor 2 is connected to the bottom outlet of the external reactor to pass the deactivated transition metal oxide 4 into the second reactor 2; at the same time, an air inlet is provided at the bottom of the second reactor 2, and the deactivated transition metal oxide 4 is regenerated by oxygen by heating under an air atmosphere. A gas outlet is also provided at the top of the second reactor 2, which is connected to the gas inlet at the top of the internal reactor to pass the oxygen-deficient air after the regeneration reaction into the internal reactor as a carrier gas for the pyrolysis gas or a low-oxygen promoting gas for the difficult-to-pyrolyze solid fuel. It can also carry a portion of energy to supplement the heat required for coke production to meet specific production needs. The first reactor 1 and the second reactor 2 can achieve switching between fixed bed and fluidized bed by adjusting the gas flow rate or gas flow direction, and can ensure sufficient gas-solid contact between the pyrolysis gas and the transition metal oxide 4, thereby improving the conversion rate of the pyrolysis gas. In the device for simultaneously achieving pyrolysis gas removal and in-situ coke preparation provided by the present invention, the reaction temperature of the first reactor 1 and the second reactor 2 is 800-1000° C., and the operating pressure is normal pressure.

[0023] Furthermore, the transition metal oxide 4 is iron oxide, copper oxide or manganese oxide, or a natural ore or smelting solid waste containing this active ingredient; for desulfurization, it can be impregnated or mixed with a certain proportion of CaO; the removal of reducing HCN and NH3 can be achieved by using a high-potential metal oxide or impregnating a second metal oxide (NiO).

[0024] The specific working process of the device for simultaneously achieving pyrolysis gas removal and in-situ coke production provided by the present invention is as follows: the first reactor 1 and the second reactor 2 are heated to a preset reaction temperature, and then the solid fuel 5 and the transition metal oxide 4 are introduced from the top of the internal reactor and the external reactor, respectively. The solid fuel 5 is pyrolyzed in the internal reactor to generate in-situ coke and pyrolysis gas, wherein the pyrolysis gas enters from the bottom of the external reactor through the through-holes on the reactor wall 3, fully contacts the transition metal oxide 4 from bottom to top, generates CO2 and H2O, and is discharged from the top of the external reactor. The reduced transition metal oxide 4 is deactivated and discharged from the bottom of the external reactor into the second reactor 2. Air enters from the bottom of the second reactor 2, so that the deactivated transition metal oxide 4 is oxidized and regenerated, and can be used as a supplementary transition metal oxide 4 to re-enter the external reactor. The oxygen-deficient air generated at the same time can be directly discharged or sent to the internal reactor to promote the occurrence of the pyrolysis reaction, thereby achieving the simultaneous removal of pyrolysis gas and in-situ coke production.

[0025] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for simultaneously achieving pyrolysis gas removal and in-situ coke production, characterized in that: The device comprises a first reactor (1), wherein the first reactor (1) is divided into an internal reactor and an external reactor by a reactor wall (3); the internal reactor is used to introduce solid fuel (5) to perform in-situ coke preparation and simultaneously generate pyrolysis gas; the lower end of the reactor wall is opened to release the pyrolysis gas generated by the internal reactor into the external reactor; the external reactor is used to introduce a transition metal oxide (4) to oxidize the pyrolysis gas, thereby simultaneously achieving pyrolysis gas removal and in-situ coke preparation; The apparatus for simultaneously achieving pyrolysis gas removal and in-situ coke production further comprises a second reactor (2), wherein a top inlet of the second reactor (2) is connected to a bottom outlet of the external reactor so that the deactivated transition metal oxide (4) is introduced into the second reactor (2); and an air inlet is provided at the bottom of the second reactor (2) so that the deactivated transition metal oxide (4) is regenerated by heating in an air atmosphere. The top of the second reactor (2) is also provided with a gas outlet, which is connected to the gas inlet at the top of the internal reactor and is used to pass the oxygen-deficient air after the regeneration reaction into the internal reactor; The lower end of the reactor wall (3) is provided with a porous sintered plate for preventing solid particles from escaping to the external reactor; The internal reactor is designed to have a structure in which solid fuel (5) is added from the top and the particles move downward. The external reactor is designed to have a structure in which fresh transition metal oxide (4) is added from the top, the particles move downward, and the pyrolysis gas moves upward, so as to fully oxidize the pyrolysis gas and simultaneously realize the conversion of tar into gas phase. The CO2 and H2O produced in the external reactor are discharged through the upper end of the external reactor, and high-purity CO2 can be obtained by condensation. The transition metal oxide (4) is iron oxide, and is further doped with CaO and / or NiO.

2. The device for simultaneously achieving pyrolysis gas removal and in-situ coke production according to claim 1, characterized in that: The solid fuel (5) includes coal powder, biomass or biocoke.

3. The device for simultaneously achieving pyrolysis gas removal and in-situ coke production according to claim 1 or 2, characterized in that: The reaction temperature of the first reactor (1) and the second reactor (2) is 800-1000°C.

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