Pyrolysis gasification combustion synergistic electric filtration coupled electrocatalytic exhaust gas purification pyrolysis device

Abstract

The invention discloses a pyrolysis device for purifying tail gas with pyrolysis, gasification and combustion coordinated by electric filtration and electrocatalysis, which comprises a shell, a porous cylindrical negative electrode arranged at the center of the shell, and the inner cavity of the shell is divided into a gasification combustion chamber and a pyrolysis chamber outside the gasification combustion chamber, a spiral sheet is arranged on the outer wall of the negative electrode, a rotating disk is movably arranged on the top of the shell through a bearing, the top of the negative electrode is fixed on the inner ring of the bearing and driven to rotate by the rotating disk, the rotating disk is fixed on the output shaft of the motor, an exhaust gas discharge port is opened on the rotating disk and is connected to the gasification combustion chamber, a catalyst layer is arranged on the upper inner part of the negative electrode, and one end of the needle-shaped positive electrode is fixed in the catalyst base layer; the device utilizes the combustion of pyrolysis gas to provide heat for pyrolysis, does not need to continuously provide fuel gas, greatly reduces the cost of pyrolysis treatment, and simultaneously adopts electric filtration coupled electrocatalysis to purify tail gas, realizes dust removal and gas purification treatment of tail gas, and reduces environmental protection risks.

Description

Technical Field

[0001] The invention relates to a pyrolysis, gasification and combustion coordinated electric filtration coupled electrocatalytic tail gas purification pyrolysis device, belonging to the field of organic solid waste treatment. Background Art

[0002] Pyrolysis is usually carried out under anaerobic or anoxic conditions, and the drying, high-temperature decomposition, gasification, and combustion of garbage are placed in different single reaction vessels for operation. Compared with the conventional layer-burning garbage incineration technology, this pyrolysis treatment technology produces less flue gas, and the required purification device is smaller than the traditional garbage treatment device. Pyrolysis treatment technology can be carried out through two processes: pyrolysis and gasification reaction at 450-600°C and melting and combustion of carbon-containing residues at more than 1300°C. Therefore, pyrolysis treatment technology is also called the latest garbage treatment technology in the 21st century. Garbage pyrolysis technology can treat various types of solid waste including domestic garbage, and the pyrolysis system can be realized through modularization, which is simple to install and easy to move. As a new type of garbage treatment technology, it is highly efficient and suitable for remote areas such as rural areas. It is friendly to the local environment and will not produce excess metabolic pollution. The garbage pyrolysis process is to use high temperature and anoxic conditions to produce thermochemical decomposition of organic matter in the garbage due to its carbon content, and generate gas and liquid pigments. Garbage pyrolysis is the process of converting the organic components in the garbage into combustible gas, tar and ash under the reaction of a reducing agent. The tar and ash are finally discharged as derivatives of the pyrolysis treatment. With the increasing number of organic solid waste types and increasingly stringent environmental protection requirements, the requirements for pyrolysis equipment are also getting higher and higher. On the one hand, the pyrolysis temperature requirements must be met, the pyrolysis cost must be reduced, and the tail gas must be harmlessly treated.

[0003] In order to improve the pyrolysis efficiency of organic waste, Wuhan Tianying Environmental Engineering Co., Ltd. invented a biomass rotary propulsion pyrolysis device, the patent number of which is: CN201710169319.0, comprising a pyrolysis device, the pyrolysis device being connected to a rotating device, the pyrolysis device comprising a feed pipe (1), a discharge pipe (8) and a plurality of pyrolysis tubes (4), the outlet of the feed pipe (1) being respectively connected and fixed to the inlet of the plurality of pyrolysis tubes (4), the outlet of the plurality of pyrolysis tubes (4) being respectively connected and fixed to the inlet of the discharge pipe (8), the feed pipe (1) being provided with a feed spiral blade (2), the discharge pipe (8) being provided with a discharge spiral blade (9), and the pyrolysis tube (4) being provided with a pyrolysis spiral blade (5), wherein the “several” here refers to one or more, thereby improving the pyrolysis efficiency of organic matter. Dalian University of Technology has disclosed a whole-tire rapid pyrolysis device and method for waste tires, with patent number CN201910544896.2. Holes are symmetrically opened on the sidewalls of the waste tires. The opened waste tires are fed into a folding feeding device, and are fed into the lower middle part of a whole-tire rapid pyrolysis device after being isolated from the air by a water seal section. The high-temperature molten salt from the molten salt heating and reflux device provides energy for the catalytic rapid pyrolysis of the waste tires. Pyrolysis volatile products and carbon black are generated during the pyrolysis process. The carbon black is fed into a carbon black recovery device by a telescopic sealing scraper for collection, and the pyrolysis volatile products are fed into a pyrolysis volatile product recovery device for collection. At the same time, the steel wire precipitated during the pyrolysis process is drawn out of the whole-tire rapid pyrolysis device by a wire drawing device. During the pyrolysis process, the temperature of the molten salt continues to decrease, and is pumped back to the molten salt heating and reflux device by a molten salt pump for heat storage. The molten salt that has stored heat is returned to the whole-tire rapid pyrolysis device again. However, this method is only applicable to the pyrolysis of tires, and is not applicable to other organic wastes. Existing technologies and equipment often focus mainly on pyrolysis efficiency, while the treatment of pyrolysis gas and subsequent tail gas purification are often ignored. Summary of the invention

[0004] Pyrolysis technology has become the mainstream technology for organic solid waste treatment due to its prospect of high added value resource treatment. However, the existing pyrolysis technology still has problems such as low pyrolysis efficiency, high cost, inability to dispose on a large scale, and easy to cause organic gas pollution. To solve these problems, the present invention proposes a pyrolysis gasification combustion synergistic electric filtration coupled electrocatalytic exhaust gas purification pyrolysis device. The device combines pyrolysis and gasification combustion, uses the heat generated by gasification combustion to provide energy for pyrolysis, and the combustible gas and tar and other substances generated by pyrolysis provide fuel for combustion, forming a closed-loop pyrolysis gasification combustion equipment.

[0005] The device of the present invention comprises a shell, a porous cylindrical negative electrode is arranged at the center of the shell, and the inner cavity of the shell is divided into a gasification combustion chamber and a pyrolysis chamber located outside the gasification combustion chamber, a spiral sheet is arranged on the outer wall of the negative electrode, a rotating disk is arranged on the top of the shell through a bearing, the top of the negative electrode is fixed on the inner ring of the bearing and is driven to rotate by the rotating disk, the rotating disk is fixed on the output shaft of the motor, an exhaust gas discharge port is opened on the rotating disk and is connected to the gasification combustion chamber, a catalyst layer is arranged on the upper part of the negative electrode, one end of the needle-shaped positive electrode is fixed in the catalyst base layer, and the other end is arranged at the center of the gasification combustion chamber; a grate is arranged at the bottom of the shell, an ash hopper is fixed at the lower end of the shell, a feed port is opened on one side of the upper part of the shell, one end of the gas inlet pipe is arranged outside the shell, and the other end is arranged at the bottom of the gasification combustion chamber and a gas distribution port is arranged thereon; one end of the air inlet pipe is arranged outside the shell, and the other end is arranged at the bottom of the gasification combustion chamber and an air distribution port is arranged thereon, and a lighter is arranged on one side of the gas distribution port, and the positive electrode and the negative electrode are respectively connected to a power source.

[0006] A heat-insulating layer is arranged outside the shell, and the material of the heat-insulating layer is one of rock wool board, extruded polystyrene board, expanded polystyrene, glass wool, polyurethane foam material and perlite; a one-way plate is arranged in the feed port.

[0007] The fuel gas is used to provide heat during startup, and the fuel gas is one of natural gas, liquefied petroleum gas, and biogas.

[0008] The negative electrode is made of one of nickel-based alloy and graphite, and the diameter of the hole is 1-10 mm. The positive electrode is made of one of graphite, Cr-Mo steel, Pt-Ag alloy, Ni-Cr-Co alloy and Ni3Al alloy.

[0009] The pyrolysis materials mainly include organic solid wastes such as domestic garbage, agricultural straw, dead branches and leaves, medical garbage, and sludge, and the moisture content is less than 15%.

[0010] The electric field voltage is 110V~360V.

[0011] The catalyst in the catalyst layer is a conventional catalyst used for combustion flue gas purification, such as a honeycomb or granular vanadium-tungsten-titanium catalyst, a platinum-titanium-vanadium catalyst, a platinum-copper catalyst, an iron-neodymium catalyst and a complex iron catalyst.

[0012] Organic solid waste enters from the feed port, and the pyrolysis reaction is started first. The gas enters the gasification combustion chamber from the gas intake pipe, and the air is introduced from the air intake pipe at the same time. The lighter ignites the gas, and the heat from the combustion in the gasification combustion chamber provides heat for the external pyrolysis chamber. The pyrolysis time and speed of the organic solid waste can be controlled by the rotation speed of the spiral blade, which is also a propulsion device for the organic solid waste feed. When the heat generated by the gasification combustion chamber can provide the heat required for the pyrolysis of the organic solid waste, the gas is turned off. The pyrolysis gas of organic matter enters the gasification combustion chamber through the holes on the porous cylindrical high-temperature resistant negative electrode for combustion, providing gas for combustion. The liquid fuel of tar produced by pyrolysis will leak into the gasification combustion chamber through the porous cylindrical high-temperature resistant negative electrode under the action of temperature for combustion, and the combustion further provides the required heat for the pyrolysis chamber. The ash produced by pyrolysis and gasification combustion flows down to the ash hopper, and the pyrolysis gas and tar and other substances produced by pyrolysis enter the gasification combustion chamber for combustion to provide heat for pyrolysis. An electric field is arranged in the gasification combustion chamber. During the catalytic combustion, a large number of free radicals and plasma are produced, which have a significant effect on gas purification. At the same time, the dust produced by gasification combustion is enriched and removed on the negative electrode under the action of the electric field. The flue gas after combustion passes through the catalyst layer, and the flue gas that is not completely treated by the electric field is further catalytically purified. The catalysts are honeycomb or granular high-temperature resistant materials loaded with highly active rare metals. When the combustion flue gas such as SO2, NOx, VOC gas, etc. passes through the catalyst layer, it will be quickly adsorbed first, and then catalytically converted into resource-usable or harmless components such as SO3 and N2 under the action of highly active rare metals, so as to realize efficient catalytic purification of tail gas.

[0013] The equipment uses the combustion of pyrolysis gas to provide heat for pyrolysis, and does not require a continuous supply of fuel gas, greatly reducing the cost of pyrolysis treatment. At the same time, it uses electric filtration coupled with electrocatalytic exhaust purification to achieve exhaust gas dust removal and gas purification treatment, reducing environmental risks. A rotating disk is used to drive the gasification combustion chamber to rotate, accurately controlling the feed and pyrolysis speeds, making its heat distribution more uniform and reducing the generation of harmful substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the device of the present invention;

[0015] In the figure: 1-rotating disk; 2-feeding port; 3-one-way plate; 4-insulation layer; 5-gas distribution port; 6-gas inlet pipe; 7-ash hopper; 8-grate; 9-air inlet pipe; 10-air distribution port; 11-negative electrode; 12-spiral sheet; 13-positive electrode; 14-catalyst layer; 15-exhaust gas outlet. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below by way of examples, but the protection scope of the present invention is not limited to the contents described above.

[0017] Embodiment 1: The device of this embodiment includes a shell, a heat preservation layer 4 is arranged outside the shell, a porous cylindrical negative electrode 11 is arranged at the center of the shell, and the inner cavity of the shell is divided into a gasification combustion chamber and a pyrolysis chamber located outside the gasification combustion chamber, a spiral sheet 12 is arranged on the outer wall of the negative electrode 11, and a rotating disk 1 is movably arranged on the top of the shell through a bearing (the outer ring of the bearing is fixed at the opening at the top of the shell, the rotating disk is fixed on the inner ring of the bearing, and the inner and outer rings of the bearing are sealed), the top of the negative electrode 11 is fixed below the inner ring of the bearing and is driven to rotate by the rotating disk, the rotating disk 1 is fixed on the output shaft of the motor, an exhaust gas discharge port 15 is opened on the rotating disk 1 and is connected to the gasification combustion chamber, a catalyst layer 14 is arranged on the upper part of the negative electrode 11, one end of the needle-shaped positive electrode 13 is fixed in the catalyst base layer, and the other end It is arranged at the center of the gasification combustion chamber; a grate 8 is arranged at the bottom of the shell, an ash hopper 7 is fixed at the lower end of the shell, a feed port 2 is opened on one side of the upper part of the shell, a one-way plate 3 is arranged in the feed port, one end of the gas inlet pipe 6 is arranged outside the shell, and the other end is arranged at the bottom of the gasification combustion chamber and a gas distribution port 5 is installed thereon; one end of the air inlet pipe 9 is arranged outside the shell, and the other end is arranged at the bottom of the gasification combustion chamber and an air distribution port 10 is installed thereon, and a lighter is arranged on one side of the gas distribution port 5, wherein the insulation layer is made of rock wool board, the gas is natural gas, the porous cylindrical negative electrode is made of nickel-based alloy with a pore size of 1mm, the needle-shaped positive electrode material is graphite, and medical waste with a water content of 8% is treated. The electric field voltage is 110V, and the catalyst in the catalyst layer is a complex iron catalyst.

[0018] Medical waste enters from the feed port 2, and the pyrolysis reaction is first started. The gas is introduced into the gasification combustion chamber from the gas inlet pipe 6, and the air is introduced from the air inlet 9. The lighter ignites the gas, and the heat generated by the combustion in the gasification combustion chamber provides heat for the pyrolysis in the pyrolysis chamber outside it. The pyrolysis time and speed of the medical waste can be controlled by the rotation speed of the spiral blade. The spiral blade 12 is also a propulsion device for the medical waste. When the heat generated by the gasification combustion chamber can provide the heat required for the pyrolysis of the medical waste, the gas is turned off. The pyrolysis gas of the medical waste enters the gasification combustion chamber through the porous cylindrical negative electrode 11 for combustion, providing gas for combustion and providing the required heat for the pyrolysis chamber. The liquid fuels such as tar generated by pyrolysis will leak through the porous cylindrical negative electrode 11 to the gasification combustion chamber for combustion under the action of temperature, further providing the required heat for the pyrolysis chamber. The ash produced by pyrolysis and gasification combustion flows down to the ash hopper 7, and the pyrolysis gas and tar and other substances produced by pyrolysis enter the gasification combustion chamber for combustion to provide heat for pyrolysis. The gasification combustion chamber is provided with an electric field. While catalytic combustion, a large amount of free radicals and plasma are produced, which have a significant effect on gas purification. At the same time, the dust produced by gasification combustion is enriched and removed on the negative electrode under the action of the electric field; the flue gas after combustion is purified by the catalyst layer 14 and then discharged;

[0019] Results: The ash produced by pyrolysis of 1 ton of medical waste is 20 kg, and the NOx concentration of tail gas is 20 mg / m 3 , SO2 concentration is 11mg / m 3 , the particle concentration is 10mg / m 3 .

[0020] Example 2: The device structure of this example is the same as that of Example 1, except that the material of the insulation layer is expanded polystyrene, the fuel gas is liquefied petroleum gas, the material of the porous cylindrical negative electrode is graphite, and its pore size is 10 mm; the needle-shaped positive electrode material is Pt-Ag alloy; the electric field voltage is 360 V, and the catalyst in the catalyst layer is an iron-neodymium catalyst.

[0021] The above device is used to treat domestic waste with a moisture content of 10%. The method is the same as in Example 1. The results are as follows: the ash produced by pyrolysis of 1 ton of domestic waste is 40 kg, and the NOx concentration of the tail gas is 10 mg / m 3 , SO2 concentration is 8mg / m 3 , the particle concentration is 15mg / m 3 .

[0022] Example 3: The device structure of this example is the same as that of Example 1, except that the insulation layer is made of polyurethane foam, the fuel gas is biogas, the porous cylindrical negative electrode is made of nickel-based alloy with a pore size of 5 mm, the needle-shaped positive electrode is made of Ni-Cr-Co alloy, the electric field voltage is 220 V, and the catalyst in the catalyst layer is a platinum-copper catalyst.

[0023] The above device was used to treat straw with a moisture content of 5%, and the method was the same as in Example 1. The results showed that the ash produced by pyrolysis of 1 ton of agricultural and rural straw was 15 kg, and the NOx concentration of the tail gas was 5 mg / m 3 , SO2 concentration is 6mg / m 3 , the particle concentration is 8mg / m 3 .

Claims

1. A pyrolysis, gasification and combustion synergistic electrofiltration coupled electrocatalytic tail gas purification pyrolysis device, characterized in that: The invention comprises a shell, a porous cylindrical negative electrode (11) is arranged at the center of the shell, and the inner cavity of the shell is divided into a gasification combustion chamber and a pyrolysis chamber located outside the gasification combustion chamber. A spiral sheet (12) is arranged on the outer wall of the negative electrode (11). A rotating disk (1) is movably arranged on the top of the shell through a bearing. The top of the negative electrode (11) is fixed on the inner ring of the bearing and driven to rotate by the rotating disk. The rotating disk (1) is fixed on the output shaft of the motor. An exhaust gas discharge port (15) is opened on the rotating disk (1) and is connected to the gasification combustion chamber. A catalyst layer (12) is arranged on the upper part of the negative electrode (11). 4), one end of the needle-shaped positive electrode (13) is fixed in the catalyst substrate, and the other end is arranged at the center of the gasification combustion chamber; a grate is arranged at the bottom of the shell, an ash hopper (7) is fixed at the lower end of the shell, a feed port (2) is opened on one side of the upper part of the shell, one end of the gas inlet pipe (6) is arranged outside the shell, and the other end is arranged at the bottom of the gasification combustion chamber and a gas distribution port (5) is installed on it; one end of the air inlet pipe (9) is arranged outside the shell, and the other end is arranged at the bottom of the gasification combustion chamber and an air distribution port (10) is installed on it, and a lighter is arranged on one side of the gas distribution port (5).

2. The pyrolysis, gasification and combustion combined with electric filtration and electrocatalytic exhaust gas purification pyrolysis device according to claim 1 is characterized in that: A heat-insulating layer (4) is arranged outside the shell, and a one-way plate (3) is arranged inside the feed port.

3. The pyrolysis, gasification and combustion combined with electric filtration and electrocatalytic exhaust gas purification pyrolysis device according to claim 1 is characterized in that: The fuel gas is one of natural gas, liquefied petroleum gas and biogas.

4. The pyrolysis, gasification and combustion combined with electric filtration and electrocatalytic exhaust gas purification pyrolysis device according to claim 1 is characterized in that: The negative electrode is made of a nickel-based alloy or graphite, and the diameter of the hole thereon is 1 to 10 mm.

5. The pyrolysis, gasification and combustion combined with electric filtration and electrocatalytic exhaust gas purification pyrolysis device according to claim 1 is characterized in that: The positive electrode material is one of graphite, Cr-Mo steel, Pt-Ag alloy, Ni-Cr-Co alloy, and Ni3Al alloy.

6. The pyrolysis, gasification and combustion synergistic electrofiltration coupled electrocatalytic tail gas purification pyrolysis device according to claim 1 is characterized by: The catalyst is one of a honeycomb or granular vanadium-tungsten-titanium catalyst, a platinum-titanium-vanadium catalyst, a platinum-copper catalyst, an iron-neodymium catalyst, and a complex iron catalyst.

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