A large amount of dispersed asphalt fume with a concentration of 5-7mg/m~3 is produced during the production process of the carbon workshop of the alumina plant. If it is directly discharged, it will have a serious impact on the surrounding environment and factory workers. Aiming at this pitch fume, small particle calcined coke is used to absorb and purify it, and the saturated calcined coke is regenerated by thermal regeneration method.

Firstly, the adsorption process of calcined coke was studied, and the effects of adsorption temperature, pitch fume concentration, space velocity and particle size of calcined coke on the adsorption effect of calcined coke were analyzed. The research results show that the amount of pitch fume adsorbed by calcined coke increases with the increase of the inlet concentration of pitch fume. Low space velocity, low temperature, and small particle size are all beneficial to the adsorption of pitch fume by calcined coke. The adsorption thermodynamics of calcined coke was studied, which indicated that the adsorption process was physical adsorption. The regression of the adsorption isotherm shows that the adsorption process conforms to the Langmuir equation.

Secondly, heating regeneration and condensation recovery of saturated calcined coke. The effects of carrier gas flow rate, heating temperature, saturated calcined coke amount and regeneration times on the regeneration efficiency of calcined coke were investigated respectively. The experimental results show that when the carrier gas flow rate increases, the heating temperature increases, and the amount of coke after saturated calcining decreases, it is beneficial to the improvement of regeneration efficiency. Condensate and absorb the regeneration tail gas, and the recovery rate is above 97%, which shows that the condensation and absorption method can recover the bitumen in the regeneration tail gas well.

Finally, the three systems of gas collection, purification and regeneration are designed, and the design results are put into practice. The results of industrial application show that the purification efficiency of asphalt fume and benzo(a)pyrene reaches 85.2% and 88.64%, respectively, when the purifier is used to capture and purify scattered and unorganized asphalt fumes. The concentrations of asphalt smoke and benzo(a)pyrene at the outlet of the purifier were 1.4mg/m~3 and 0.0188μg/m~3, and the emissions were 0.04kg/h and 0.57×10~(-6)kg/h, respectively. It has reached the secondary standard of comprehensive discharge of air pollutants GB16297-1996.