✍ Scribed by M Sänger; J Werther; T Ogada
No coin nor oath required. For personal study only.
Incineration is one of the major methods for the disposal of sewage sludge. Currently, several plants are incinerating mechanically dewatered (wet) sludge (20±40 wt.% d.m.) or semi-dried sewage sludge (30±55 wt.% d.m.), although some plants burn dry sludge (with more than 80 wt.% d.m.). Whereas signi®cant information is available on NO x and N 2 O emissions characteristics of wet and dry sludge, not much has been reported on semi-dried sludge. This paper presents some of the results obtained from the combustion of semi-dried sludge in a semi-pilot scale ¯uidised bed combustor (150 mm in diameter and 9 m high) together with some measurements from a large-scale FBC incineration plant (7 m 2 bed area, 9 m high and a capacity of 3 t/h dry sludge). The investigations have shown that semi-dried sludge exhibit emission characteristics which are similar to those of wet sludge. NO x decreases slightly whereas N 2 O remains more or less the same with increase in oxygen concentrations. Just like wet sludge, staged combustion was not effective for the reduction of NO x and N 2 O. However, increasing the freeboard temperature led to rapid reduction of N 2 O and some NO x reduction was achieved using ¯ue gas recycling technique. Comparison shows that the results from the test rig were more or less similar to those obtained from the large-scale plants.
📜 SIMILAR VOLUMES
09 Combustion (burners, combustion systems) ignition takes place close to the grate, followed by a reaction front propagating from the grate up to the surface of the bed. Hence, the progress combustion in the bed is opposite to the expected one.
## (In Japanese) The method is carried out by charging O-containing plastic (e.g. PET) into the coke oven on the top of the coal charge. ## 02/01461 The influence of SO2 level and operating conditions on NOx and N=O emissions during fluidised bed combustion of coals Miecio, F. et al. Fuel, 2001,
Limestone addition to a coal-®red ¯uidized bed combustor usually results in an increase in NO/NO x emissions and a decrease in N 2 O emissions. This observation has been explained in the literature by the effect of limestone on: (i) the conversion of coal volatile-N to NO/NO x and N 2 O; (ii) the de
In Japanese) The method is carried out by charging O-containing plastic (e.g. PET) into the coke oven on the top of the coal charge.