Experimental study on fluidized bed incineration of pulp and paper mill sludge

摘要

The disposal of pulp and paper mill sludge is a problem confronting the paper industry. Under the influence of environment protection and economic factors, previous landfilling and lagooning become less viable. Compared with conventional firing technologies, fluidized bed incineration is suitable for combustion of pulp and paper sludge with high moisture content of about 65% and very low heating value. Based on understanding from the cold fluidization test and the pyrolysis test, systematic incineration tests of the sludge were conducted on the fluidized bed combustion test rig with the dense bed of 0.23m × 0.23m in cross section and the total height of 5.03m. The feasibility of incineration of pulp and paper mill sludge in fluidized bed combustor is evaluated. The effects of several parameters, such as moisture content, fluidizing velocity, portion of the secondary air flow and excess air coefficient, etc. on the combustion performance of sludge are examined. Without any sorbent addition, the concentrations of gaseous pollutants, SO{sub}2, NO{sub}x and N{sub}2O in flue gas are quite low and can meet the national emission standard.