
Products of incineration

sifting
 fine material include ash, metal fragments,
glass, unburnt organic substances etc..

residue
 all solid material that are left after
incineration
 remove continuously or in batches

clinker and fly ash
 10% is the fused ashes, etc.. is use as
component of cement, concrete or road
making.
 the fly ash comes from the gas scrubbing
unit
 the quantity of fly ash usually 12 – 15
kg/tonne of refuse
 also used in cement making, concrete,
brick and road making

suspended particulates

flue gas
vented air emitted from a chimney after
combustion in burner. It can include
nitrogen oxides, carbon dioxides, water
vapor, sulfur dioxides, particles and many
chemical pollutants
(FSL)
the equipments used to remove are:
 the fabric filter – almost 100%
efficiency
 electronic precipitations -96 – 100%
efficiency
wet scrubbers – 94 – 97%
 cyclones – 60 – 65%
 settling chamber – 10 – 30%
 wetted baffle spray – 10 – 53%

waste gas
 removed via the stack
 the high and diameter depends amount
of climatic and lanscaping of the area

heavy metal
 found in the stack gas, bottom ash, filter
dust or in salt and sludges from dust
cleaning
 the heavy metal are:
 Cd, Cl, Cr, Cu, F, Pb, Hg, Ni, S and Zn.
Fraction
%
Stack gas
%
Bottom ash
%
Filter dust
%
Salt and sludges from
gas cleaning %
Cadmium
0.04
11
85
3.6
Chlorine
0.12
9
15
76
Chromium
0.01
94
5.8
0.27
Copper
0.01
95
4.9
0.53
Fluorine
1.5
69
3.0
26
Lead
0.01
75
24
0.9
Mercury
2.1
7
5.1
86
Nickel
0.04
87
13
0.61
Sulphur
0.47
50
10
40
Zinc
0.05
49
51
0.7

Acid Gas

SO2, HCL and HF can be remove by three
methods
 wet method
 Dry method
 semi dry method

Wet method
 Pollutions are removed by large
quantities of slaked lime or aqueous
sodium hydroxide in Ventury scrubbing
system

The limestone mixed by two ways:
 with the waste before incineration
 introduce separately into the furnace

Semi dry method
used a spray of lime (CaO) mixed with
water into the flue gas flow

Organic pollutant – high level of toxicity

Persistence in the environment

The emission of dioxin can be control
with further treated of flue gas by;

adsorption onto activated carbon filters

catalyst uses:
 mix metal oxide catalyst
 destroy the dioxin by reaction with O2
NOx controlled by in fluidised bed
incinerator by controlling the amount
of air inlet to the cobustion process
 Where NOx production cannot be
prevented, it is remove by the injection
of urea or ammonia into the flue gas.

Advantages of incineration

incineration is sanitary, odourless and
dustless

residue only 20% of the original weight and
can be used for making cement and other
materials for construction industry

require very little space and very few
personnel

can be located centrally even within the town
and reducing transportation costs.

energy production and other by-product
could generated revenue

ash and other residue are pathogen-free

pre sorting and recycle could be incorporated
and this reduces the volume to be incinerated

Disadvantages of incineration

high capital cost and high operating cost

take time to plan, design construction

require skill personnel

disposal of ash require landfill

may cause air pollution and long term
environmental effect
THANK YOU