A system for purifying a waste CO2 carrier gas from pulverized coal transport

Abstract

The application discloses a kind of powder coal conveying waste CO2 carrier gas purification system, including scrubber, the top of the scrubber is equipped with waste gas outlet, bottom is equipped with CO2 carrier gas import and circulating liquid outlet, tower is sequentially provided from top to bottom in tower with high-efficiency liquid distributor, demisting packing, secondary spray layer, secondary water washing packing, lift cap, primary spray layer, primary water washing packing and tower kettle;Circulating liquid processing unit, including circulating liquid transmission module;The application belongs to the technical field of industrial waste gas purification, and the technical effects reached are as follows: the traditional static mass transfer process is reformed into pulse fluid;Circulating pump periodically outputs high peak value flow liquid stream, forms instantaneous scouring force on the surface of packing, and peels off adhered dust;Synchronously in liquid stream reference flow stage, inject pulse air flow into tower kettle to generate rising bubble cloud, prevent solid settlement and concretion;Bubble cloud diffuses to the bottom of packing layer, and forms reverse shear flow with falling circulating liquid, destroys static liquid film and enhances interface turbulence.

Description

Technical Field

[0001] This invention relates to the field of industrial waste gas purification technology, specifically to a purification system for transporting waste CO2 carrier gas from pulverized coal. Background Technology

[0002] Pneumatic conveying of pulverized coal is a core process in coal gasification. Using pressurized CO2 instead of N2 as the carrier gas for pulverized coal conveying can optimize the composition of syngas. However, the waste CO2 carrier gas after pulverized coal conveying contains a large amount of dust, H2S, and various recalcitrant organic compounds (such as CO, CH4, and C2 hydrocarbons). Existing treatment technologies have significant drawbacks: traditional water washing or floating valve towers can remove some dust and H2S, but they are ineffective against VOCs such as CO and CH4, and high dust levels can cause blockages inside the tower. Direct catalytic oxidation can degrade VOCs, but dust can clog the catalyst pores and cause deactivation. With increasingly stringent environmental regulations, there is an urgent need to develop a highly efficient purification system that can synergistically remove dust, sulfides, and broad-spectrum VOCs (especially recalcitrant components) and can operate stably for a long period of time.

[0003] Therefore, it does not meet the existing requirements, so we propose a purification system for transporting waste CO2 carrier gas from pulverized coal. Summary of the Invention

[0004] Therefore, the present invention provides a purification system for transporting waste CO2 carrier gas from pulverized coal to solve the above-mentioned problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] According to a first aspect of the present invention, a purification system for waste CO2 carrier gas transported by pulverized coal includes: a scrubbing tower, wherein the scrubbing tower is provided with a waste gas outlet at the top, a CO2 carrier gas inlet and a circulating liquid outlet at the bottom, and a high-efficiency liquid distributor, a demisting packing, a secondary spray layer, a secondary water washing packing, a gas lifting cap, a primary spray layer, a primary water washing packing and a tower bottom are arranged sequentially from top to bottom inside the tower.

[0007] The circulating liquid treatment unit includes a circulating liquid transmission module. The input end of the circulating liquid transmission module is connected to the circulating liquid outlet, and the output end is connected to the primary spray layer and the secondary spray layer.

[0008] The catalytic oxidation unit includes a gas mixer, a gas-liquid separator, a heat exchanger, an electric heater, and a catalytic oxidation reactor, which are connected end to end in sequence. The input end of the gas mixer is connected to the exhaust gas outlet of the scrubbing tower and the air intake module. The output end of the catalytic oxidation reactor is connected to the second input end of the heat exchanger. The high-temperature gas exchanges heat with the scrubbed and mixed gas transmitted in the heat exchanger, thereby preheating it.

[0009] Furthermore, the circulating fluid transfer module includes a circulating pump and a circulating water filter, which are connected by a pipeline.

[0010] Furthermore, it also includes a pulse perturbation unit, the pulse perturbation unit comprising:

[0011] The frequency converter installed in the circulating pump is used to generate periodic pulsed liquid flow;

[0012] A microporous aeration pipeline network is installed at the bottom of the tower, which is connected to the main carrier gas pipeline via a bypass; and a pulse gas valve is installed between the aeration pipeline network and the bypass.

[0013] The pulse valve controls the opening and closing of the aeration pipeline network, and is synchronized in the opposite direction to the liquid flow pulse.

[0014] Furthermore, the operation logic of the pulse perturbation unit is as follows:

[0015] The circulating pump operates at the baseline flow rate and periodically switches to a peak flow rate of 150% to 180%, with the peak flow rate lasting for 10 to 20 seconds and the cycle lasting for 1 to 2 minutes.

[0016] The pulse gas valve is opened for 5 to 10 seconds only when the circulating liquid is at the reference flow rate, injecting a pulse gas flow of 5% to 10% of the total main gas flow into the column bottom;

[0017] The liquid flow pulse and the gas flow pulse have an inverse synchronous timing relationship.

[0018] Furthermore, the pulsed airflow performs the following functions through the microporous aeration network: generating rising bubble clouds in the slurry at the bottom of the tower; the bubble clouds rise to the bottom of the primary water washing packing, generating reverse shear force on the falling circulating liquid, destroying the static liquid film and enhancing the turbulence at the gas-liquid mass transfer interface.

[0019] Furthermore, the periodic pulsed fluid flow is configured to perform the following functions:

[0020] Peak flow stage: instantaneous high-pressure scouring is formed on the surface of the secondary and primary water washing packings to remove attached dust;

[0021] Baseline flow stage: Provides a stable mass transfer environment, and enhances the gas-liquid contact efficiency at the bottom of the packing layer with rising pulsed airflow.

[0022] Furthermore, the output end of the gas mixer is connected to the input end of the gas-liquid separator, the output end of the gas-liquid separator is connected to the input end of the first set of channels of the heat exchanger, the output end of the first set of channels is connected to the input end of the electric heater, and the output end of the electric heater is connected to the input end of the catalytic oxidizer.

[0023] Furthermore, the output end of the catalytic oxidizer is connected to the input end of the second set of channels of the heat exchanger, and the output end of this set of channels is connected to the chimney.

[0024] Furthermore, the heat exchanger is composed of a low-temperature exhaust gas heat exchanger and a high-temperature exhaust gas heat exchanger.

[0025] Furthermore, the gas before catalysis passes through a low-temperature exhaust gas heat exchanger and a high-temperature exhaust gas heat exchanger in sequence for gradient temperature preheating; the gas after catalysis passes through a high-temperature exhaust gas heat exchanger and a low-temperature exhaust gas heat exchanger in sequence for gradient temperature cooling.

[0026] The present invention has the following advantages:

[0027] 1. This purification system for transporting waste CO2 carrier gas from pulverized coal decomposes the waste gas purification process into a three-stage precision control system of "washing and impurity removal - catalytic decomposition - energy internal circulation"; the staged washing tower blocks the liquid short circuit through the gas lifting cap, making the first-stage area a dust collector and the second-stage area a hydrogen sulfide absorption pool; the catalytic oxidation unit is transformed into a self-sustaining heat cycle by leveraging the waste heat recovery network.

[0028] 2. The purification system for transporting waste CO2 carrier gas from pulverized coal establishes a thermal regeneration channel in the catalytic oxidation unit: the high-temperature exhaust gas discharged from the catalytic reactor is not directly discharged, but flows through a nested heat exchanger, like blood returning to the source, continuously transferring heat to the low-temperature intake gas to be treated, so that the originally waste heat energy is converted into the core power to drive the reaction, and the electric heater only needs to make up for the system heat loss.

[0029] 3. This purification system for transporting waste CO2 carrier gas from pulverized coal transforms the traditional static mass transfer process into a pulsed fluid process. The circulating pump periodically outputs a high-peak flow rate liquid flow, which forms an instantaneous scouring force on the surface of the packing material, stripping away the attached dust. Simultaneously, at the liquid flow reference flow stage, a pulsed airflow is injected into the bottom of the tower to generate rising bubble clouds, preventing solid sedimentation and caking. When the bubble clouds diffuse to the bottom of the packing layer, they form a reverse shear flow with the falling circulating liquid, destroying the static liquid film and enhancing interfacial turbulence. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the principle of a purification system for transporting waste CO2 carrier gas from pulverized coal, as proposed in this invention.

[0031] Figure 2 This is a schematic diagram illustrating the principle of Example 2;

[0032] Figure 3 This is a schematic diagram illustrating the control of airflow and liquid flow in Example 2;

[0033] Figure 4 for Figure 3 Liquid flow and gas flow control logic diagram;

[0034] Figure 5 This is a schematic diagram of the interior of the tower vessel in Example 2. Detailed Implementation

[0035] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1;

[0037] Reference Figure 1 A purification system for waste CO2 carrier gas transported by pulverized coal includes a scrubbing tower. The scrubbing tower has a waste gas outlet at its top, a CO2 carrier gas inlet on one side of its bottom, a circulating liquid outlet and a bottom waste liquid outlet on the other side of its bottom. From top to bottom, the scrubbing tower is equipped with a high-efficiency liquid distributor, demister packing, a secondary spray layer, a secondary circulating liquid inlet, a secondary water washing packing, a gas lift cap, a primary spray layer, a primary circulating liquid inlet, and a primary water washing packing. A demineralized water inlet is located on one side of the upper part of the scrubbing tower body, and the demineralized water inlet is connected to the input end of the high-efficiency liquid distributor. The circulating liquid outlet is connected to a circulating pump, and the output end of the circulating pump is connected to a circulating water filter. The output end of the circulating water filter is split and connected to the input ends of the secondary spray layer and the primary spray layer, respectively.

[0038] Specifically: The high-efficiency liquid distributor is located at the top of the scrubbing tower and receives makeup water from the demineralized water inlet. Its core function is to evenly distribute the liquid (mainly demineralized water) across the entire cross-section of the tower. Uniform liquid distribution is the key to the efficient operation of the packed tower. It ensures that the subsequent demisting packing and the area below the secondary spray layer can be uniformly wetted by the liquid, avoiding channeling and wall flow, maximizing gas-liquid contact efficiency, and improving the scrubbing and demisting effects.

[0039] The demisting packing is located immediately below the high-efficiency liquid distributor; it is selected from at least one of alumina, silica, ceramic, stainless steel, and plastic, and its shape can be any of spherical, Pall ring, Raschig ring, or stepped ring; it is a structured packing; its function is to capture tiny droplets (mist) entrained in the rising gas flow; to prevent droplets from being carried out of the top of the tower by the exhaust gas and into the subsequent catalytic oxidation unit; this protects the equipment of the catalytic oxidation unit (such as catalyst and heat exchanger) from droplet corrosion or blockage, and reduces the loss of valuable process water, ensuring that the exhaust gas is visually clean (no "white smoke"); it is a key component to ensure that the exhaust gas meets emission standards and that downstream equipment is safe;

[0040] The secondary spray layer is located below the demisting packing; it consists of pipes and multiple atomizing nozzles, receiving the filtered secondary circulating liquid from the circulating water filter; the nozzles atomize the circulating liquid into fine droplets and spray them downwards, forming a dense droplet curtain; its core function is to perform "fine washing" or "final washing" on the relatively clean but still slightly impurity-containing gas that rises after the primary washing; the fine droplets provide a huge gas-liquid contact surface area, effectively capturing residual extremely fine dust particles and trace amounts of gaseous pollutants (such as residual H2S) in the gas; it is a key step in ensuring that the final outlet exhaust gas particulate matter and H2S content meet the standards;

[0041] The secondary washing packing is located below the secondary spray layer; it is typically composed of stacked packings with large specific surface area and high porosity (such as polypropylene Pall rings, structured metal packing, etc.); it receives liquid falling from the secondary spray layer; it provides a large, continuous gas-liquid mass transfer contact surface; the rising gas flows in a tortuous manner between the packing voids, making full contact with the liquid film formed on the packing surface; its main function is to deeply remove hydrogen sulfide (H2S) and some soluble VOCs from the gas; the packing structure promotes turbulence, prolongs the gas-liquid contact time, and improves the dissolution and absorption efficiency of acidic gases such as H2S; it is the main functional area for H2S removal; through full contact and mass transfer of gas and liquid on the packing surface, efficient removal of H2S can be achieved, and particulate matter concentration can be further reduced;

[0042] A riser cap is typically a structure with a riser pipe and a cap, located above the primary washing packing layer. It forces the gas to change its flow direction (usually from radial or annular flow within the packing layer to upward flow through the riser pipe). It serves three functions: 1. Preventing liquid short-circuiting: preventing liquid from the upper layer (secondary zone) from directly falling into the lower layer (primary zone) liquid collection area, avoiding direct circulation or discharge of liquid that has not fully participated in washing; 2. Promoting gas-liquid separation: at the riser cap, the gas velocity may change, helping to initially separate larger entrained droplets and allow them to fall back into the packing layer; 3. Uniform gas distribution: helping to distribute the gas relatively evenly throughout the upper secondary washing packing layer.

[0043] Primary spray layer: Located below the gas lift cap (or above the primary packing); its structure is similar to the secondary spray layer, receiving the primary circulating liquid output from the circulating water filter; it also atomizes the liquid through nozzles; forming a droplet curtain to "roughly wash" or "initially wash" the raw CO2 waste carrier gas that has just entered from the bottom of the tower and has the highest pollutant concentration; its main function is to remove most of the dust particles, some H2S, and any larger droplets or tar-like substances that may be entrained in the gas; it bears the main particulate matter removal load and part of the H2S load, protecting the packing layer above from being blocked too quickly;

[0044] The primary water washing packing is located below the primary spray layer and above the bottom liquid level. Its structure is similar to that of the secondary water washing packing or may use a more clogging-resistant packing form, providing a large gas-liquid contact surface for preliminary mass transfer absorption of the rising, highly polluted gas. Its main function is to further remove dust (especially that not captured by the spray layer), absorb most of the H2S, and cool and saturate the gas. It is the first barrier for the system to handle high pollution loads and is crucial to preventing clogging and corrosion of subsequent equipment (such as circulating pumps, filters, and secondary systems).

[0045] The bottom of the washing tower collects all the washing liquid from top to bottom, providing sufficient residence time for solid particles to settle and for dissolved gases (such as CO2 and H2S) to have room to release. The settled solid particles (fly ash, etc.) form a slurry. Through the bottom waste liquid outlet, the waste liquid containing high concentrations of solids and dissolved salts is continuously discharged from the system (sent to an off-site treatment area) by a waste liquid pump, preventing solid accumulation and salt concentration. Most of the relatively clean upper clear liquid is drawn away by a circulating pump through the circulating liquid outlet, and after the residual solid particles are removed by the circulating water filter, it is returned to the spray layer for recycling, significantly reducing fresh water consumption and wastewater generation. The settling function of the bottom tower is key to maintaining the cleanliness of the circulating liquid and preventing solid accumulation in the system. The setting of the circulating water filter is crucial, as it can effectively remove fine particles in the circulating liquid, prevent nozzle clogging and packing contamination, and ensure long-term stability of washing efficiency. The design of continuous waste discharge and continuous replenishment of demineralized water maintains the balance of water quality and salt concentration in the system.

[0046] Working principle: CO2 waste carrier gas enters the scrubbing tower through the CO2 carrier gas inlet. The scrubbing tower operates at a temperature of 5-60℃ and a pressure of 18-25 kPaG. The circulating liquid enters the secondary and primary spray layers through the circulating pump and circulating water filter, flowing from top to bottom. This allows the rising CO2 waste carrier gas to come into countercurrent contact with the descending circulating water, washing away particulate matter and a small amount of hydrogen sulfide from the gas. Through countercurrent contact (gas from bottom to top, liquid from top to bottom) and staged treatment (primary coarse washing / initial washing, secondary fine washing / final washing), the cascade removal of pollutants is achieved. The scrubbing process is also a process of gas cooling and humidification (saturation), providing relatively stable temperature and humidity conditions for the subsequent catalytic oxidation unit.

[0047] Waste liquid from the bottom of the tower is continuously pumped to the outside of the boundary area, and most of the circulating liquid from the bottom of the tower is recycled through a circulating pump. The system needs to be continuously replenished with demineralized water, which is sent to the top of the washing tower through a demineralized water pump. After washing, the tail gas enters the catalytic oxidation unit to treat methanol, CO, CH4, C2H6, C2H4 and other VOCs before being discharged into the air.

[0048] Furthermore: the top exhaust outlet of the scrubbing tower is connected to a catalytic oxidation unit, which includes a gas mixer. The gas mixer has two sets of input terminals, one connected to the exhaust outlet and the other connected to an air intake module. The air intake module includes an air fan and an air filter. The output terminal of the air filter is connected to the input terminal of the air fan, and the output terminal of the air fan is connected to the input terminal of the gas mixer.

[0049] The exhaust gas from the scrubbing tower is mixed with air in a gas mixer. The exhaust gas and filtered air are mixed in the required ratio (usually to meet the oxygen demand of catalytic oxidation and control the VOCs concentration within a safe range). After mixing, it enters a gas-liquid separator to further separate any trace amounts of free water. Then, it undergoes heat exchange in a heat exchanger. After heat exchange, it is precisely heated to the ignition temperature required for the catalytic oxidation reaction by an electric heater. It then enters the catalytic oxidation reactor for the catalytic oxidation reaction. Under the action of a precious metal catalyst, harmful volatile organic compounds (VOCs) such as methanol, CO, CH4, C2H6, and C2H4 in the exhaust gas are oxidized and decomposed at 300-600℃ (normal pressure operation), efficiently converting them into harmless carbon dioxide (CO). 2) The high-temperature purified flue gas is then passed through a high-temperature tail gas heat exchanger (used for secondary preheating of the gas entering the catalytic oxidation reactor) and a low-temperature tail gas heat exchanger (used for primary preheating of the gas entering the catalytic oxidation reactor) to further recover heat. The purified flue gas is then cooled to near ambient temperature and completely harmless before being discharged in compliance with emission standards.

[0050] Example 2:

[0051] Similar to Example 1, the technical problem with the above solution is that in the scrubbing tower, the gas and liquid phases mainly contact each other on the packing surface in a film-like manner, and the mass transfer efficiency is limited by the liquid film renewal rate and the degree of interfacial turbulence; for pulverized coal waste gas with high dust and easy scaling, the lower part of the packing layer is prone to blockage, and the upper part is prone to channeling, and the overall efficiency decreases over time. Furthermore, referring to... Figure 2 - Figure 5 A purification system for transporting waste CO2 carrier gas from pulverized coal involves modifying the control program of the circulating pump to output periodic pulse flow rates. Specifically, a frequency converter is added to the circulating pump to control the flow rate pulses. The pulse mode, for example, switches between a baseline value (e.g., 100%) and a peak value (e.g., 150%–180%) every 1–2 minutes, with the peak value lasting 10–20 seconds. During the high peak flow rate, the liquid exerts a brief but strong scouring force on the packing layer, stripping away dust and deposits adhering to the packing surface and preventing blockage. Simultaneously, the strong liquid flow impact disrupts the stable liquid film, enhancing interface renewal and turbulence, and instantaneously improving mass transfer efficiency (especially for H2S absorption).

[0052] A microporous aeration network is installed at the bottom of the tower. The input end of the microporous aeration network is connected to the bypass of the main carrier gas pipeline, utilizing a small portion of the main gas flow. A pulse gas valve is installed at the connection between the two.

[0053] Pulse mode: Synchronized with but in the opposite direction to the liquid side pulse; when the liquid is in a high flow pulse, the pulse gas valve is closed; the pulse gas valve is preferably a DN20 pneumatic quick-opening valve. When the liquid is at the reference flow rate, the pulse gas valve is briefly opened (e.g., 5-10 seconds) to instantly inject a small stream (5%-10% of the total gas volume) of high-speed gas flow into the circulating liquid zone below the column bottom.

[0054] The gas stream is injected upwards into the slurry at the bottom of the tower. The gas pulse generates localized rising bubble clouds and turbulence in the slurry, disturbing the slurry, promoting the suspension of solid particles and preventing sedimentation and caking. At the same time, this disturbed bubble group naturally diffuses to the bottom of the packing layer during its ascent, forming a gentle disturbance and creating a slight upward shock wave at the bottom of the packing layer. This shock wave forms an instantaneous strong countercurrent shear with the liquid falling from above, further breaking up the liquid film and bubbles, and greatly enhancing the gas-liquid contact efficiency.

[0055] Example 3:

[0056] Similar to Example 1, but further: a purification system for conveying waste CO2 carrier gas from pulverized coal, wherein an online pH / ORP monitoring probe is added inside the tower bottom (using the existing waste liquid outlet flange for installation), and the alkalinity of the replenished demineralized water is automatically adjusted according to the real-time monitoring value (such as injecting a trace amount of NaOH solution into the demineralized water pipeline);

[0057] Working principle: When a decrease in H2S removal rate is detected (pH<6.5), the alkalinity of the desalinated water is increased (pH=8-9) to enhance the absorption efficiency of H2S by the primary / secondary packing material; when the ORP value is >200mV (excessive oxidation of sulfides), the alkalinity is reduced to prevent salt crystallization.

Claims

1. A system for purifying a CO2-laden gas stream from a pulverized coal delivery system, comprising: a CO2 removal unit; a CO2 storage unit; and a CO2 recovery unit. The application relates to a catalytic oxidation device for treating waste gas, which comprises the following parts: a washing tower, which is provided with a waste gas outlet at the top and a CO2 carrier gas inlet and a circulating liquid outlet at the bottom, and is sequentially provided with a high-efficiency liquid distribution device, a demisting filler, a secondary spraying layer, a secondary water washing filler, a gas lifting cap, a primary spraying layer, a primary water washing filler and a tower kettle from top to bottom; a circulating liquid treatment unit, which comprises a circulating liquid transmission module, the input end of the circulating liquid transmission module is connected with the circulating liquid outlet, and the output end is branched and connected with the primary spraying layer and the secondary spraying layer; a catalytic oxidation unit, which comprises a gas mixer, a gas-liquid separator, a heat exchanger, an electric heater and a catalytic oxidation reactor, which are sequentially connected in a head-tail mode, the input end of the gas mixer is communicated with the waste gas outlet of the washing tower and an air inlet module; the output end of the catalytic oxidation reactor is connected with the second input end of the heat exchanger, and high-temperature gas is heat-exchanged with the washing mixed gas transmitted in the heat exchanger, so that the high-temperature gas is preheated; the circulating liquid transmission module comprises a circulating pump and a circulating water filter, and the two are connected through pipelines; the device further comprises a pulse disturbance unit, which comprises: a frequency converter arranged on the circulating pump, which is used for generating a periodic pulse liquid flow; a microporous aeration pipe network arranged at the bottom of the tower kettle, which is connected with a main carrier gas pipeline through a bypass, and a pulse air valve is arranged between the aeration pipe network and the bypass; the pulse air valve controls the opening and closing of the aeration pipe network, and is reversely synchronized with the liquid flow pulse.

2. A system for purifying a CO2-laden gas from a pulverized coal delivery system according to claim 1, wherein the operation logic of the pulse disturbance unit is as follows: the circulating pump runs at a reference flow rate and is periodically switched to a peak flow rate of 150% to 180%, the peak lasts for 10 to 20 seconds and the cycle is 1 to 2 minutes; the pulse air valve is only opened for 5 to 10 seconds when the circulating liquid is at the reference flow rate, and a pulse gas flow accounting for 5% to 10% of the total main gas flow is injected into the tower kettle; the liquid flow pulse and the gas flow pulse are reversely synchronized in time sequence.

3. A system for purifying a CO2-laden gas from a pulverized coal delivery system as recited in claim 2, wherein The pulse gas flow performs the following functions through the microporous aeration pipe network: generating rising bubble clouds in the slurry in the tower kettle; the bubble clouds rise to the bottom of the primary water washing filler, generate reverse shear force on the falling circulating liquid, destroy the static liquid film and enhance the turbulence of the gas-liquid mass transfer interface.

4. A system for purifying a CO2-laden gas from a pulverized coal delivery system as recited in claim 3, wherein The periodic pulse liquid flow is configured to perform the following functions: high peak flow rate stage: forming a transient high-pressure flushing on the surface of the secondary water washing filler and the primary water washing filler, and stripping the attached dust; reference flow rate stage: providing a stable mass transfer environment, and cooperating with the rising pulse gas flow to enhance the gas-liquid contact efficiency at the bottom of the filler layer.

5. A system for purifying a CO2-laden gas from a pulverized coal delivery system as recited in claim 1, wherein, the output end of the gas mixer is connected with the input end of the gas-liquid separator, the output end of the gas-liquid separator is connected with the input end of the first group of channels of the heat exchanger, the output end of the group is connected with the input end of the electric heater, and the output end of the electric heater is connected with the input end of the catalytic oxidation device.

6. A system for purifying a CO2-laden gas from a pulverized coal delivery system as recited in claim 5, wherein, the output end of the catalytic oxidation device is connected with the input end of the second group of channels of the heat exchanger, and the output end of the group is connected with a chimney.

7. A system for purifying a CO2-laden gas from a pulverized coal delivery system as recited in claim 6, wherein, the heat exchanger is composed of a low-temperature tail gas heat exchanger and a high-temperature tail gas heat exchanger.

8. A system for purifying a CO2-laden gas from a pulverized coal delivery system as recited in claim 7, wherein, The gas before catalysis is sequentially subjected to gradient preheating through the low-temperature tail gas heat exchanger and the high-temperature tail gas heat exchanger; and the gas after catalysis is sequentially subjected to gradient cooling through the high-temperature tail gas heat exchanger and the low-temperature tail gas heat exchanger.

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