Agriculture Reference
In-Depth Information
3.
P
ULP
E
NERGY
R
ECOVERY
A
SSESSMENT
Typically, pulp has a very high moisture content of the order of above 70% and hence a
very low net calorific value of 3.20 MJ/kg. The pulp can offer feeding problems due its high
moisture content and sticky nature. Therefore, it may have to be blended with an easy flowing
fuel to make consistency in the feeding.
Compositions of the coal-pressed pulp blends tested are 50/50, 60/40 and 70/30 by mass
in the thermal input range of 11.8 to 19.7 kW at flue gas O
2
concentrations ranging from 5 to
12.8%. Analyses of all the three coal-pulp blends tested are given Table 9. The results of the
experiments with coal-pulp blends are summarized and compared with coal only firing in
Table 10.
Table 9. Analysis of Coal-Pulp Blends
Coal
Pressed pulp
50/50 blend
60/40 blend
70/30 blend
Carbon (%) AR
74.42
14.1
44.3
50.3
56.3
Hydrogen (%) AR
4.06
1.8
2.93
3.16
3.38
Oxygen (%) AR
6.97
10.9
8.94
8.5
8.1
Nitrogen (%) AR
1.62
0.14
0.88
1
1.2
Sulphur (%) AR
2.01
0.14
1.08
1.26
1.45
Chlorine (%) AR
0.63
0
0.32
0.38
0.44
Moisture (%) AR
5.6
71
38.3
31.76
25.22
Ash (%) AR
*
4.9
2
3.45
3.74
4.03
Volatiles (%) AR
34.2
25.1
29.7
30.6
31.5
Fixed carbon (%) AR
55.3
1.9
27.4
32.4
37.5
Ash (%) Dry
5.19
6.9
5.7
5.6
5.52
Volatiles (%) Dry
36.23
86.55
49.05
45.85
43.13
Fixed carbon (%) Dry
58.58
6.55
45.25
48.55
51.35
C (%, DAF
$
)
82.96
52.07
75.79
77.78
79.42
H (%, DAF)
4.53
6.65
5.02
4.88
4.77
O (%, DAF)
7.77
40.25
15.3
13.21
11.49
N (%, DAF)
1.81
0.52
1.51
1.59
1.66
S (%, DAF)
2.24
0.52
1.84
1.95
2.04
St. Air (Nm
3
/kg of fuel)
8.01
1.5
4.76
5.41
6.06
A/F ratio (kg/kg)
9.6
1.8
5.7
6.48
7.26
CV Net, (MJ/kg)
30.1
3.2
16.65
19.34
22.03
Air/NCV (kg/MJ)
0.32
0.56
0.34
0.335
0.33
Contribution
Coal (MJ/kg)
30.1
0
15.05
18.06
21.07
PP (MJ/kg)
0
3.2
1.6
1.28
0.96
Coal (%)
100
0
90.4
93.4
95.6
Pressed pulp (%)
0
100
9.6
6.6
4.4
*
AR = As Received;
$
DAF = Dry Ash Free
