Waste gas waste heat recovery and purification process of mixed gas heating system

Abstract

The invention relates to a waste gas waste heat recovery and purification process of a mixed gas heating system. Coke oven waste flue gas generated in the coke oven heating process is subjected to heat exchange cooling and carbon dioxide removal treatment and then fed into a dry quenching furnace to cool high-temperature coke; the waste flue gas discharged from the dry quenching furnace enters a primary dust remover, a desulfurizing agent is sprayed into the primary dust remover, and SO2 in the waste flue gas is removed; the desulfurized waste flue gas enters a waste heat boiler for recovery of heat carried by the desulfurized waste flue gas, and the outlet temperature of the waste flue gas is controlled through the waste heat boiler, so that the waste flue gas discharged after heat exchange directly enters an SCR denitration device to be denitrated; and the denitrated waste flue gas is subjected to heat exchange cooling and secondary dust removal and then sent to a chimney to be discharged. According to the invention, the red coke waste heat and the coke oven waste flue gas waste heat are recycled, and the coke oven waste flue gas is purified, so that the flue gas emission meets the national standard, the atmospheric pollution is reduced, the greenhouse gas emission is reduced, and the coke quality is ensured.

Description

technical field [0001] The invention relates to the technical field of coking waste heat recovery and flue gas purification, in particular to a waste gas waste heat recovery and purification process of a mixed gas heating system. Background technique [0002] During coke oven production, coal gas (coke oven gas or mixed gas) burns in the combustion chamber and supplies heat to the carbonization chamber at the same time, and the high-temperature flue gas generated by combustion is discharged after heat exchange in the regenerator. -300℃, called coke oven waste gas. Coke oven production uses a mixed gas heating system that mainly uses blast furnace gas mixed with coke oven gas to remove N carried in the air from the waste flue gas 2 , CO produced after combustion 2 and H 2 O, also contains a small amount of residual O 2 and SO produced during combustion 2 , NO X , SO contained in coke oven flue gas 2 is one of the important sources of air pollution, NO X It is one of t...

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Problems solved by technology

It is also introduced into the coke oven waste gas desulfurization and denitrification system, but because this part of the released gas contains a relatively high concentration of dust, it is necessary to add necessary dust removal facilities, and at the same time reduce the temperature of the coke oven waste gas to a certain extent. This will adversely affect the operation of the coke oven waste gas desulfurization and denitrification system

[0005] In order to effectively recover the waste heat of red coke and coke oven waste flue gas, and complete the purification of coke oven waste flue gas at the same time, the waste heat recovery and desulfurization and denitrification purification process and CDQ can be adopted by heating and burning the mixed gas. The coke process is integrated to form a process system, but due to the CO generated by combustion in the waste flue gas 2 The volume accounts for about 20% of the exhaust gas, when the CO in the exhaust gas 2 When in contact with hot coke in the CDQ furnace, a certain degree of carbon melting reaction will occur with the coke to generate CO, which not only increases the content of combustible components in the waste flue gas, but also brings certain safety hazards to the operation of the system. A certain amount of coke is also consumed due to the occurrence of carbon melting reaction, resulting in the "burning loss" of coke and the reduction of coke quality

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