粉煤热解干法熄焦余热回收工艺流程分析及模试

Aiming at the problems of the large consumption of water resources, high moisture content of semi-coke, and severe environmental pollution in the production process of pulverized coal pyrolysis, the process flow of semi-coke dry quenching and waste heat recovery for drying pulverized coal by using inert gas as the cooling medium was proposed. The influence of initial temperature, water content, flow rate of different circulation media (nitrogen, carbon dioxide, flue gas, and coal gas) on the temperature of quenching semi-coke and preheated coal was studied by system simulation. The effect of water-saving and energy-saving was analyzed, and the model test based on 10000-ton pulverized coal pyrolysis was carried out. The results showed that the technology of waste heat recovery from dry quenching of semi-coke was feasible. The temperature of semi-coke after coke quenching and the outlet temperature of preheating coal have no significant relationship with the type of cooling medium but were closely related to the cooling medium's specific heat. Compared with the wet quenching, the dry process had a significant energy-saving effect and zero water consumption, which could reuse 65%-75% of the sensible heat of semi-coke while meeting the process requirements. Theoretical analysis and experimental results showed that dry quenching waste heat recovery had a good application prospect.