Fluidization and incineration of pulp and paper mill sludge in BFB
Incineration followed by landfilling of its residual is one of the most prospective methods for pulp and paper mill sludge disposal, which offers substantial volume reductions and heat recovery. Compared with conventional firing technologies, fluidized bed incineration is suitable for combustion of pulp and paper sludge with high moisture content of about 60%. Fluidization test of paper mill sludge with moisture of 12.75% was conducted in a cold bubbling fluidized bed (BFB) model. Particle size and weight fraction of silica sand mixed with sludge as dual-component bed materials for better fluidization are optimized. Minimum fluidizing velocity of the mixed bed materials and terminal velocity of the sludge are determined. Incineration tests of the sludge with different moisture contents were carried out in both a pilot BFB combustor and a commercial BFB incinerator with treatment capacity of 143 tons per day. Distribution of temperature along the column, combustion efficiency, pollutant emission in flue gas and combustion portions in the dense bed and the freeboard were measured and calculated. The results indicate that the sludge with less than 43% moisture content can be burned stably in the pilot BFB combustor and the sludge with even higher moisture content in the commercial incinerator without any supplemental fuel. Emission of SO{sub 2}, NO{sub x} and N{sub 2}O is very low and can meet the emission requirements. A mathematical model for incineration of the pulp and paper mill sludge alone is developed. Design considerations of the incinerator for choosing proper moisture content of the sludge, preheated air temperature, the portion of the primary air to the total air are given in the paper.
- Research Organization:
- Southeast Univ., Nanjing (CN)
- OSTI ID:
- 20006762
- Report Number(s):
- CONF-990534--
- Country of Publication:
- United States
- Language:
- English
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