Gasification synthesis gas high-temperature filtration and tar catalytic cracking purification device and method

Abstract

The invention discloses a gasified synthesis gas high-temperature filtration and tar catalytic cracking purification device which comprises a clean gas chamber, a dust filtration and gas purification chamber and a gasified ash collecting chamber which are communicated with one another from top to bottom, and an inlet unit of the dust filtration and gas purification chamber is connected with a connector unit; the connector unit is used for reducing the inflow gas speed; a plurality of filtering reaction units are arranged in the dust filtering and gas purifying chamber; each filtering reaction unit comprises a metal net sleeve sprayed with a nickel-based catalyst and an iron-based filter element arranged in the metal net sleeve; a gas blowback unit is arranged in the clean gas chamber and is used for providing high-speed gas and acting on a pipeline in the iron-based filter element. The device can improve the quality of the synthesis gas and the overall efficiency of the gasification process, effectively remove impurities such as tar and dust in the synthesis gas, promote water-gas shift reaction and produce hydrogen, and improve the quality of the synthesis gas product and the hydrogen proportion.

Description

Technical Field

[0001] The present invention relates to the technical field of synthesis gas purification, in particular to a high-temperature filtration and enhanced hydrogen production method and corresponding device for removing gasification ash and tar impurities in gasification synthesis gas. Background Art

[0002] As a key intermediate in coal chemical industry and biomass energy conversion, the purification technology of coal gasification syngas is crucial to improve the quality of syngas and the overall system efficiency. Impurities such as ash and tar generated during the gasification process will not only reduce the quality of syngas, but also cause blockage and corrosion to subsequent equipment, affecting the stable operation of the system.

[0003] At present, the preliminary purification technologies of coal gasification syngas mainly include physical washing, chemical absorption, catalytic cracking and other methods. The physical washing method uses water or other solvents to wash the syngas through equipment such as spray towers to remove ash and part of the tar, but this method has problems such as high energy consumption and easy secondary pollution. The chemical absorption method removes impurities through the reaction of chemical solvents with impurities, but there are often problems such as difficulty in solvent recovery and high operating costs. The catalytic cracking method converts large molecular organic matter such as tar into small molecular syngas components through the action of catalysts. It has the advantages of high efficiency and low energy consumption, but the selection, regeneration and cost control of catalysts are the key challenges of this technology. Therefore, the development of an efficient gasification syngas purification technology that can effectively remove impurities such as tar and dust is of great significance to promote the commercial application of biomass gasification technology. Summary of the invention

[0004] Purpose of the invention: In view of the shortcomings of the prior art, the present invention proposes a device and method for high-temperature filtration of gasified synthesis gas and catalytic cracking and purification of tar, aiming to overcome the limitations of the prior art, improve the quality of synthesis gas and the overall efficiency of the gasification process, effectively remove impurities such as tar and dust in the synthesis gas, promote the occurrence of water-gas shift reaction and produce hydrogen, and improve the quality of synthesis gas products and the proportion of hydrogen.

[0005] In order to solve the above technical problems, the present invention discloses a gasification synthesis gas high temperature filtration and tar catalytic cracking purification device, the device comprises a clean gas chamber, a dust filtration and gas purification chamber and a gasification ash collection chamber which are interconnected from top to bottom, wherein:

[0006] The inlet unit of the dust filter and gas purification chamber is connected with a connection port unit, and the connection port unit is used to reduce the inflow gas velocity; a plurality of filter reaction units are arranged in the dust filter and gas purification chamber, and each filter reaction unit includes a metal mesh sleeve sprayed with a nickel-based catalyst and an iron-based filter element arranged in the metal mesh sleeve;

[0007] A gas backflush unit is arranged in the clean gas chamber, and the gas backflush unit is used to provide high-speed gas and act on the pipeline inside the iron-based filter element.

[0008] Wherein, in the metal mesh sleeve sprayed with a nickel-based catalyst, the nickel-based catalyst is nickel metal, and the mass ratio of the nickel metal to the metal mesh sleeve is 1-3%.

[0009] Specifically, the pore size of the metal mesh sleeve is 0.5-1 mm; the metal mesh sleeve is fixedly connected to the iron-based filter element, preferably through a spiral interface, and the iron-based filter element is vertically and evenly distributed in the metal mesh sleeve.

[0010] The ratio of the inlet diameter of the inlet unit to the diameter of the connecting port is 0.05-0.07.

[0011] Preferably, the gas backflush unit is arranged in the middle position of the iron-based filter element.

[0012] The bottom of the dust filter and gas purification chamber is in the shape of a funnel with a gradually decreasing diameter, and the angle between the wall and the horizontal plane is 30-60°, preferably 45°. The gasification ash collection device is connected to the dust filter and gas purification chamber through a funnel-shaped connection port with a gradually increasing diameter, and the angle between the wall and the horizontal plane is 30-60°, preferably 45°.

[0013] The present invention further proposes a method for using the above-mentioned device to perform high-temperature filtration of gasified synthesis gas and catalytic cracking purification of tar, wherein the high-temperature synthesis gas separated from the second-stage cyclone of the gasifier is introduced into the device through the inlet unit of the dust filter and gas purification chamber, and the apparent gas velocity of the high-temperature synthesis gas is reduced through the connecting port unit, so that the inlet gas velocity is reduced from 1-3m / s at the inlet to 0.004-0.012m / s, and at the same time, a gas backflush unit is used to blow air into the filtering reaction unit, and the gasified ash generated during the reaction is collected in a dust collection bag.

[0014] The temperature of the high temperature synthesis gas is 700-950°C, and the gas space velocity of the high temperature synthesis gas is in the range of 1000-3000h -1 .

[0015] The gas back-blowing unit provides a high-frequency blowing airflow, with a nozzle pressure range of 5-10 MPa and a frequency of 5-20 Hz.

[0016] Beneficial effects: The present application filters and purifies the gasified synthesis gas at high temperature by setting an iron-based filter element with a nickel-cobalt active catalyst attached. Under the action of the catalyst on the surface of the filter element, the catalytic cracking of tar is achieved, and the tar impurities in the synthesis gas are effectively removed; the content of alkali metal impurities such as potassium and sodium in the synthesis gas is reduced; at the same time, the water-gas shift reaction is promoted to increase the proportion of hydrogen in the synthesis gas; when the high-temperature synthesis gas is introduced, the superficial gas velocity of the high-temperature synthesis gas is reduced by introducing a connecting port unit, and the sedimentation and separation of coarser ash particles is achieved to improve the separation efficiency; at the same time, by designing and arranging multiple parallel filter elements and adding a gas backflush device, fine powder ash is prevented from adhering to the surface of the filter element and clogging. The purification method and device of the present application ensure sufficient and efficient reaction through advanced process design, and prepare clean synthesis gas with low ash tar content and high hydrogen component ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0018] Figure 1 This is a schematic diagram of the device for this application;

[0019] Figure 2 This is a physical picture of the synthesis gas tar before and after passing through the device. DETAILED DESCRIPTION

[0020] like Figure 1 As shown, the present application provides a gasification synthesis gas high temperature filtration and tar catalytic cracking purification device, which includes a clean gas chamber 1, a dust filtration and gas purification chamber 2 and a gasification ash collection chamber 3 which are interconnected from top to bottom. Among them, the dust filtration and gas purification chamber 2 is used for dust filtration and removal and purification of tar impurities in the synthesis gas, and its inlet unit is connected to a connection port unit, and the inlet unit is used to receive the gasification synthesis gas transported from the upstream, and the gas is accelerated through the fine-pore diameter pipeline and then decelerated and released into the reactor through the connection port unit; a plurality of filtering reaction units 4 are arranged in the dust filtration and gas purification chamber 2, and each filtering reaction unit is provided with an iron-based filter element and a metal mesh sleeve sprayed with a nickel-based catalyst, which is used for filtering and catalytic cracking, and strengthening the water-gas shift reaction. The iron-based filter element and the metal mesh sleeve are connected by a spiral interface, and the metal mesh sleeve is mechanically fixed to the iron-based filter element by screws; one iron-based filter element is equipped with a metal mesh sleeve and is evenly distributed vertically.

[0021] The clean gas chamber 1 is used for the recovery, storage and transportation of clean gas, and contains a gas backflush unit 5, which acts on the filtering reaction unit and can pass high-speed gas to impact the internal pipeline of the filter element to generate high-frequency vibration, so as to promote the falling off of particles adhering to the outer surface, thereby preventing the fouling and clogging of the filter element surface; the outlet end is externally connected to a downstream device for gas connection and transportation;

[0022] The bottom of the dust filter and gas purification chamber is in the shape of a funnel with a gradually decreasing diameter, and the angle between the wall and the horizontal plane is 45°. The gasification ash collection device is connected to the dust filter and gas purification chamber through a funnel-shaped connection port with a gradually increasing diameter, and the angle between the wall and the horizontal plane is 45°.

[0023] The gasification ash collecting device comprises a funnel-shaped connecting port with a decreasing diameter and an ash collecting chamber.

[0024] The device of the present application can effectively realize the catalytic cracking of tar, effectively remove tar impurities in synthesis gas, and reduce the content of alkali metal impurities such as potassium and sodium in the synthesis gas; at the same time, it promotes the water-gas shift reaction and increases the proportion of hydrogen in the synthesis gas.

[0025] The following is a detailed description of the high-temperature filtration and enhanced hydrogen production for removing gasification ash and tar impurities in gasification synthesis gas using the device of the present invention through specific embodiments.

[0026] In the following embodiments, the height of the dust filter and gas purification chamber of the device used is 400cm, the inner diameter is 336.6cm, the inlet unit diameter is 20.40cm, and the connection port diameter is 336.6cm, wherein 23 filtering reaction units are evenly arranged in the dust filter and gas purification chamber, each filtering reaction unit, inner diameter 26.6cm, diameter 33.4cm after the metal mesh sleeve is put on, and the length is 200cm. In the metal mesh sleeve sprayed with a nickel-based catalyst, the nickel-based catalyst is nickel metal, and the mass ratio of nickel metal to the metal mesh sleeve is 3%. After the equipment is operated for 10-20 days, the metal mesh sleeve is blocked and needs to be cleaned and maintained in time, and the iron-based filter element does not need to be replaced. According to the known gas flow processing capacity (set according to the reaction kinetics and the requirements for cleaning and purification of synthetic gas), the effective area and quantity of the filter element and the metal mesh sleeve are designed and adjusted.

[0027] Embodiment 1 (i.e. 1#)

[0028] The high-temperature synthesis gas separated from the second-stage cyclone of the gasifier is introduced into the device through the inlet unit of the dust filter and gas purification chamber. The gas space velocity of the high-temperature synthesis gas is 1500-2000h-1. -1 The superficial gas velocity of the high-temperature synthesis gas is reduced by the connecting port unit, so that the inlet gas velocity is reduced from 2-2.5 m / s at the inlet to 0.004-0.012 m / s. At the same time, the gas backflush unit is used to blow air to the filtering reaction unit with a pressure range of 6-8 MPa and a frequency of 4-15 Hz. The gasified ash generated during the reaction is collected in a dust collection bag.

[0029] Embodiment 2 (i.e. 2#)

[0030] Another batch of high-temperature synthesis gas separated from the second-stage cyclone of the gasifier was treated using the same operating conditions. The composition of the high-temperature synthesis gas and the effect after treatment are shown in Tables 1 and 2.

[0031] Table 1 shows the changes in the composition of the gasified syngas before and after passing through the device. The hydrogen (H2) content increased significantly, while the carbon monoxide (CO) content decreased significantly. The results in Table 1 show that, under the promotion of the catalyst on the surface of the filter element, the tar was effectively converted into carbon monoxide and hydrogen, which reduced the carbon dioxide content. At the same time, the catalyst on the surface of the filter element also promoted the water-gas shift reaction, reduced the carbon monoxide ratio in the syngas, and increased the hydrogen ratio in the syngas, which is crucial for subsequent energy utilization and chemical synthesis processes.

[0032] Table 1 Changes in gasification syngas components before and after passing through the device (volume ratio %)

[0033] sample <![CDATA[H2]]> CO <![CDATA[CH4]]> <![CDATA[CO2]]> Passing the device before 1# 24.5 42.4 6.9 26.2 After passing the device 1# 40.8 32.9 3.9 22.3 Passing the device before 2# 23.4 42.4 6.1 28.1 After passing the device 2# 38.7 31.6 3.8 25.9

[0034] The actual pictures of syngas tar before and after passing through the device are as follows Figure 2 As shown in Table 2, the content changes. Figure 1 As shown, after the gasified synthesis gas passes through the device, the color in the tar collection bottle changes from brown-black to light yellow and becomes more transparent, indicating that the complex components in the tar are cracked to a certain extent, effectively removing the tar impurities in the synthesis gas, reducing the load burden of the downstream pipeline and the reactor, and increasing the proportion of the effective component hydrogen in the synthesis gas. The data in Table 2 show that the tar content is significantly reduced after passing through the device, and the tar conversion rate is above 40%, which proves the effective performance of the present invention in tar purification. These significant improvements not only demonstrate the obvious advantages of the present invention compared with the prior art, but also provide an innovative solution for the field of synthesis gas purification.

[0035] Table 2 Changes in tar content before and after passing through the device

[0036]

[0037] The above two groups of experiments are the experimental results under stable parameter conditions through long-term testing, which are highly representative and reliable. The biomass processing capacity is 20kg / h, the gasification temperature is 850℃, the experiment reacts continuously for 48 hours, and the tar content in the stable state is tested. The test data are the test analysis data under the stable state.

[0038] The present invention provides a gasification synthesis gas high temperature filtration and tar catalytic cracking purification device and method. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A gasification synthesis gas high temperature filtration and tar catalytic cracking purification device, characterized in that: The device comprises, from top to bottom, a clean gas chamber (1), a dust filtration and gas purification chamber (2), and a gasification ash collection chamber (3) which are interconnected, wherein: The inlet unit of the dust filtration and gas purification chamber (1) is connected to a connection port unit, and the connection port unit is used to reduce the inflow gas velocity; a plurality of filtering reaction units (4) are arranged in the dust filtration and gas purification chamber (2), and each filtering reaction unit comprises a metal mesh sleeve sprayed with a nickel-based catalyst and an iron-based filter element arranged in the metal mesh sleeve; A gas backflush unit (5) is provided in the clean gas chamber, and the gas backflush unit (5) is used to provide high-speed gas and act on the pipeline inside the iron-based filter element.

2. The device according to claim 1, characterized in that In the metal mesh sleeve sprayed with a nickel-based catalyst, the nickel-based catalyst is nickel metal, and the mass ratio of the nickel metal to the metal mesh sleeve is 1-3%.

3. The device according to claim 1, characterized in that The pore size of the metal mesh sleeve is 0.5-1 mm; the metal mesh sleeve is fixedly connected to the iron-based filter element, preferably through a spiral interface, and the iron-based filter element is vertically and evenly distributed in the metal mesh sleeve.

4. The device according to claim 1, characterized in that The ratio of the inlet diameter of the inlet unit to the diameter of the connecting port is 0.05-0.

07.

5. The device according to claim 1, characterized in that The gas backflush unit (5) is arranged in the middle of the iron-based filter element.

6. The device according to claim 1, characterized in that The bottom of the dust filter and gas purification chamber is in the shape of a funnel with a gradually decreasing diameter, and the angle between the wall and the horizontal plane is 30-60°. The gasification ash collection device is connected to the dust filter and gas purification chamber through a funnel-shaped connection port with a gradually increasing diameter, and the angle between the wall and the horizontal plane is 30-60°.

7. A method for high-temperature filtration of gasified synthesis gas and catalytic cracking and purification of tar using the device according to claim 1, characterized in that: The high-temperature synthesis gas separated from the second-stage cyclone of the gasifier is introduced into the device through the inlet unit of the dust filter and gas purification chamber, and the apparent gas velocity of the high-temperature synthesis gas is reduced through the connecting port unit, so that the inlet gas velocity is reduced from 1-3m / s at the inlet to 0.004-0.012m / s. At the same time, the gas backflush unit is used to blow air into the filtering reaction unit, and the gasified ash generated during the reaction process is collected in the dust collection bag.

8. The method according to claim 5, characterized in that The temperature of the high temperature synthesis gas is 700-950°C, and the gas space velocity range of the high temperature synthesis gas is 1000-3000 h -1 .

9. The method according to claim 5, characterized in that The gas back-blowing unit provides a high-frequency blowing airflow, with a nozzle pressure range of 5-10 MPa and a frequency of 5-20 Hz.

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