A full recovery process for carbon dioxide discharged from a catalytic cracking regeneration device, wherein a system required by the process includes the catalytic cracking regeneration device, a flue gas recovery device, a high-temperature flue gas fan, an oxygen production device, and a carbon-based gas mixer;
- wherein
- the carbon-based gas mixer includes an oxygen channel, an oxygen channel regulating valve, a flue gas recirculation channel, an oxygen distributor, a mixer, a carbon-based gas channel, and an oxygen concentration analyzer;
- wherein
- the oxygen distributor is a hollow cylinder, and a plurality of small holes are evenly provided on a peripheral wall of the hollow cylinder;
- the mixer is a hollow cylinder;
- the oxygen channel regulating valve is located on the oxygen channel, and an outlet of the oxygen channel is connected with an end of the oxygen distributor, the oxygen distributor and a part of the oxygen channel are inserted into the mixer through a side wall of the mixer;
- an outlet of the flue gas recirculation channel is connected with one end of the mixer, and an inlet of the carbon-based gas channel is connected with another end of the mixer, and the oxygen concentration analyzer is provided on the carbon-based gas channel;
- a flue gas outlet of the catalytic cracking regeneration device is connected with the flue gas recovery device, the flue gas recovery device is connected with the high-temperature flue gas fan, and a venting pipe is provided on a connection pipe between the flue gas recovery device and the high-temperature flue gas fan;
- the high-temperature flue gas fan is connected with the carbon-based gas mixer and a downstream carbon dioxide enrichment utilization device, respectively, and a first flow rate regulating valve is provided on a connection pipe between the high-temperature flue gas fan and the carbon-based gas mixer;
- an oxygen outlet of the oxygen production device is connected with the carbon-based gas mixer, and a second flow rate regulating valve is provided on a connection pipe between the oxygen outlet of the oxygen production device and the carbon-based gas mixer;
- the carbon-based gas mixer is connected with a bottom portion and an upper portion of the catalytic cracking regeneration device, respectively, a main pipe of a connection pipe of the carbon-based gas mixer and the bottom portion and the upper portion of the catalytic cracking regeneration device is provided with a flow meter, a first temperature sensor, and a first pressure sensor, and the branch pipe of the connection pipe of the carbon-based gas mixer and the bottom portion and the upper portion of the catalytic cracking regeneration device is provided with a third flow rate regulating valve;
- and
- a nitrogen outlet of the oxygen production device is connected to the main pipe of the connection pipe of the carbon-based gas mixer and the bottom portion and the upper portion of the catalytic cracking regeneration device, and an air combustion fan is connected to the main pipe of the connection pipe of the carbon-based gas mixer and the bottom portion and the upper portion of the catalytic cracking regeneration device;
- and
- the process includes:
- 1) utilizing air for combustion at an initial stage, in response to generating a flue gas, utilizing a carbon-based gas made by mixing a circulated flue gas and oxygen as a combustion agent to gradually replace the air for combustion, and after a period of circulation, completely replacing the air with the carbon-based gas for combustion, the carbon-based gas for combustion being in a normal operation;
- 2) in response to determining that the circulated flue gas enters the flue gas recovery device from the catalytic cracking regeneration device, controlling the flue gas recovery device to perform heat recovery, dedusting, and desulfurization on the circulated flue gas;
- controlling the high-temperature flue gas fan to pressurize the circulated flue gas, introducing part of a pressurized circulated flue gas into the carbon-based gas mixer via the third connection pipe, and introducing rest of the pressurized circulated flue gas into the downstream carbon dioxide enrichment utilization device via the fourth connection pipe;
- controlling the oxygen production device to introduce the oxygen into the carbon-based gas mixer, and mixing the oxygen and the circulated flue gas in the carbon-based gas mixer to produce the carbon-based gas;
- 3) controlling the carbon-based gas mixer to introduce the carbon-based gas into the bottom portion and the upper portion of the catalytic cracking regeneration device in two ways, wherein the carbon-based gas entering into the bottom portion of the catalytic cracking regeneration device is a main combustion agent providing a majority of a combustion gas for combustion of a catalyst carbon deposit in the catalytic cracking regeneration device, and the carbon-based gas entering into the upper portion of the catalytic cracking regeneration device is an auxiliary combustion agent providing the combustion gas for a small count of carbon monoxide that is not burned up in the catalytic cracking regeneration device;
- and
- 4) controlling the catalytic cracking regeneration device to feed a generated circulated flue gas to the flue gas recovery device via the connection pipe, and performing operation 2) and operation 3) again, and repeating the above operations.