CN-121990574-A - Tail gas recycling method and system for porous carbon preparation and porous carbon preparation system

CN121990574ACN 121990574 ACN121990574 ACN 121990574ACN-121990574-A

Abstract

The patent relates to the technical field of porous carbon preparation, in particular to a tail gas recycling system, which is characterized by being applied to a porous carbon preparation device and comprising an incinerator, a gas bag and a heat exchange device, wherein the incinerator is connected with the porous carbon preparation device and is used for incinerating tail gas discharged by the porous carbon preparation device, the gas bag and the heat exchange device are connected with each other, the heat exchange device is connected with the incinerator, saturated steam generated by the gas bag and tail gas of the incinerator are subjected to heat exchange in the heat exchange device to prepare superheated steam, and the superheated steam is at least partially conveyed back to the porous carbon preparation device and is used for preparing porous carbon.

Inventors

NISHIMATSU KOHIDE
HOU YANBING
LUO ZIJUAN
XU CHENG
MAO LURONG

Assignees

森松（江苏）重工有限公司

Dates

Publication Date: 20260508
Application Date: 20260206

Claims (13)

1. An exhaust gas recycling system, characterized by being applied to a porous carbon preparation device, comprising: the incinerator is connected with the porous carbon preparation device and is used for incinerating tail gas discharged by the porous carbon preparation device; The gas bag and the heat exchange device are connected with each other, the heat exchange device is connected with the incinerator, saturated steam generated by the gas bag and tail gas of the incinerator are subjected to heat exchange in the heat exchange device to prepare superheated steam, and the superheated steam is at least partially conveyed back to the porous carbon preparation device so as to be used for preparing porous carbon.
2. The tail gas recycling system according to claim 1, wherein the heat exchange device comprises a primary heat exchanger and a secondary heat exchanger, a tail gas inlet of the primary heat exchanger is connected with the incinerator, a tail gas outlet is connected with a tail gas inlet of the secondary heat exchanger, a steam inlet of the primary heat exchanger is connected with a steam outlet of the gas bag, and a steam outlet of the primary heat exchanger is connected with the porous carbon preparation device; The primary heat exchanger receives saturated steam and prepares superheated steam by means of heat of the tail gas to be transmitted to the porous carbon preparation device.
3. The exhaust gas recycling system according to claim 2, further comprising: a flash device having a hot water inlet and a steam outlet, the secondary heat exchanger having a hot water inlet and a hot water outlet; The hot water inlet of the flash evaporation device is connected with the hot water outlet of the secondary heat exchanger, the steam outlet of the flash evaporation device is connected with the first steam inlet of the air bag, and the flash evaporation device is used for preparing saturated steam and supplementing the saturated steam to the air bag.
4. The exhaust gas recycling system according to claim 3, further comprising: A liquid level gauge for measuring the liquid level in the flash device; The first regulating valve is in communication connection with the liquid level meter and is used for regulating the flow of the hot water inlet of the flash evaporation device according to the liquid level signal of the liquid level meter; And a conveying pump is also arranged between the flash evaporation device and the secondary heat exchanger, and the conveying pump is also in communication connection with the liquid level meter.
5. The exhaust gas recycling system according to claim 3, further comprising: The steam generator is connected with a second steam inlet of the air bag; a first pressure sensor in communication with the steam generator for measuring the air pressure at the steam outlet of the flash evaporation device; The steam generator generates saturated steam and transmits the saturated steam to the air bag, and the steam generator is closed after the pressure value measured by the first pressure sensor reaches a preset value and the maintaining time exceeds the preset time.
6. The exhaust gas recycling system according to claim 3, further comprising: The hot water inlet of the plate heat exchanger is connected with the hot water outlet of the secondary heat exchanger, and the hot water outlet of the plate heat exchanger is connected with the hot water inlet of the flash evaporation device so that the flash evaporation device is connected with the secondary heat exchanger through the plate heat exchanger; The plate heat exchanger also has a circulating water inlet and a circulating water outlet, which exchanges heat with circulating water to regulate the temperature of the hot water entering the flash evaporation device.
7. The exhaust gas recycling system according to claim 6, further comprising: a temperature sensor for measuring the temperature of the hot water outlet line of the plate heat exchanger; And the second regulating valve is in communication connection with the temperature sensor and is used for controlling the flow of the hot water inlet pipeline of the plate heat exchanger according to the temperature signal of the temperature sensor.
8. The exhaust gas recycling system according to claim 1, further comprising: a second pressure sensor for measuring the pressure of the air bag; The third regulating valve is in communication connection with the second pressure sensor and is arranged on a connecting pipeline of the air bag and the heat exchange device, and the third regulating valve controls the pressure of the air bag within the range of 1.5-3.0 barg according to a pressure signal provided by the second pressure sensor.
9. The tail gas recycling system according to any of claims 2 to 8, wherein the temperature of the tail gas received by the tail gas inlet of the primary heat exchanger is 900-950 ℃, and/or The temperature of the tail gas received by the tail gas inlet of the secondary heat exchanger is 500-600 ℃, and/or The temperature of the tail gas discharged from the tail gas outlet of the secondary heat exchanger is 150-200 ℃, and/or The primary heat exchanger and the secondary heat exchanger are vertical shell-and-tube heat exchangers, and the vertical shell-and-tube heat exchangers are provided with fixed tube plates and/or detachable tube plates, and/or The tail gas recycling system further comprises a tail gas environment-friendly treatment device, a tail gas outlet of the secondary heat exchanger is connected with the tail gas environment-friendly treatment device, and/or The incinerator utilizes air to support combustion and adopts natural gas as supplementary fuel.
10. A porous carbon production system, comprising: a porous carbon production device; The exhaust gas recycling system of any one of claims 1 to 9, connected to the porous carbon production apparatus.
11. The tail gas recycling method for the porous carbon preparation is characterized by comprising the following steps of: incinerating the porous carbon to prepare the discharged tail gas; converting saturated steam into superheated steam by utilizing the heat of the burnt tail gas; The resulting superheated steam is at least partially fed back to the porous carbon production unit for use in the production of porous carbon.
12. The method for recycling tail gas produced by porous carbon according to claim 11, wherein the step of converting saturated steam into superheated steam using heat of the incinerated tail gas comprises: The tail gas passes through a primary heat exchanger, and superheated steam is prepared by utilizing heat exchanged by the tail gas in the primary heat exchanger; The tail gas discharged by the primary heat exchanger passes through the secondary heat exchanger, and hot water is prepared by utilizing heat exchanged by the tail gas in the secondary heat exchanger; Preparing saturated steam by flashing at least part of the prepared hot water; The superheated steam is prepared by using the obtained saturated steam.
13. The method for recycling tail gas from porous carbon production of claim 12, further comprising, prior to the step of flashing at least part of the produced hot water to produce saturated steam: preparing saturated steam by using a steam generator; the saturated steam is conveyed to a primary heat exchanger, and superheated steam is prepared by utilizing heat exchanged by tail gas in the primary heat exchanger; after the step of flashing at least part of the hot water produced to produce saturated steam, it further comprises: obtaining a pressure value of saturated steam prepared by flash evaporation; and turning off the steam generator after the measured pressure value reaches a preset value and the maintaining time exceeds a preset time.

Description

Tail gas recycling method and system for porous carbon preparation and porous carbon preparation system Technical Field The patent relates to the technical field of porous carbon preparation, in particular to a tail gas treatment and waste heat recovery system in the porous carbon preparation process. Background With the rapid development of the fields of new energy automobiles, energy storage systems and the like, porous carbon is taken as a skeleton of a silicon-carbon anode material, and the preparation process of the porous carbon is increasingly focused. In the porous carbon preparation process, particularly when the carbonization and activation are carried out by a rotary kiln through a resin method, high-temperature tail gas containing volatile organic compounds can be generated, and the tail gas is not only subjected to environmental protection treatment, but also carries a large amount of heat energy. In the prior art, for example, CN120328550a discloses a method and a system for producing porous carbon, wherein the system is used for preheating inert gas after the tail gas from the outlet of a fluidized bed reactor is treated by a multi-stage scrubber. However, in this solution, the tail gas is subjected to a scrubber, which results in a large amount of heat being carried away by the scrubber, and only a small portion of the heat is transferred to the inert gas, resulting in a higher heat loss rate. Another prior art CN120393868a proposes to utilize the tail gas produced by the fluidized bed reactor to directly participate in the heat exchange between nitrogen and carbon source gas, so as to preheat the gas for use in the subsequent section. However, due to instability of the tail gas generation amount, the heat exchange process is difficult to regulate and control, the preheating effect cannot be ensured, and the production efficiency is affected. In addition, some processes perform waste heat recovery by modifying the kiln structure, but the equipment in the scheme has higher manufacturing and labor cost and poor economy. Disclosure of Invention In order to solve the technical problems mentioned in the background art, an aspect of the present invention provides a tail gas recycling system, which is characterized in that the tail gas recycling system is applied to a porous carbon preparation device, and includes: the incinerator is connected with the porous carbon preparation device and is used for incinerating tail gas discharged by the porous carbon preparation device; The gas bag and the heat exchange device are connected with each other, the heat exchange device is connected with the incinerator, saturated steam generated by the gas bag and tail gas of the incinerator are subjected to heat exchange in the heat exchange device to prepare superheated steam, and the superheated steam is at least partially conveyed back to the porous carbon preparation device so as to be used for preparing porous carbon. By recycling the superheated steam for preparing the porous carbon, the heat recovery efficiency is obviously improved, the raw material cost and the energy consumption for preparing the porous carbon are reduced, the tail gas treatment process is simplified, the problems of low heat recovery efficiency, high heat loss rate, unstable system operation and the like in the prior art are effectively solved, and the efficient conversion of tail gas heat to activator steam is realized. Optionally, the heat exchange device comprises a primary heat exchanger and a secondary heat exchanger, wherein a tail gas inlet of the primary heat exchanger is connected with the incinerator, a tail gas outlet of the primary heat exchanger is connected with a tail gas inlet of the secondary heat exchanger, a steam inlet of the primary heat exchanger is connected with a steam outlet of the air bag, a steam outlet of the primary heat exchanger is connected with the porous carbon preparation device, and the primary heat exchanger receives saturated steam and prepares superheated steam by means of heat of the tail gas so as to be transmitted to the porous carbon preparation device. The heat recovery efficiency is remarkably improved through the two-stage heat exchange structure, the system can stably operate and adapt to different working conditions, meanwhile, the thermal stress risk of equipment is reduced, and the problems of insufficient heat recovery and unstable system operation caused by the fact that the heat cascade utilization cannot be realized through the single-stage heat exchange structure are effectively solved. Optionally, the system further comprises a flash evaporation device, wherein the flash evaporation device is provided with a hot water inlet and a steam outlet, the secondary heat exchanger is provided with a hot water inlet and a hot water outlet, the hot water inlet of the flash evaporation device is connected with the hot water outlet of the secondary heat exchanger, the steam outlet of the flash