part 1: overview of cogeneration and its status in asia - Fire

Cogeneration in Asia today 63
Every ton of paddy processed generates around 250 kg of husk which, when used as fuel, is
capable of producing 100 kWh of electricity on an average. The milling power needed for a ton
of paddy ranges from 20 kWh for white rice production to 60 kWh for parboiling and
mechanically dried white rice. Assuming that 2.7 kg of husk are necessary to produce 1 kWh,
theoretically over 13,000 GWh/year of electricity could be generated. In practice, however,
much less may be expected from the rice-milling sector as financial analyses show power
generation to be feasible only for plants having a capacity above 5 tons/hour. As shown in
Table 1.6, rice-milling capacities of many ASEAN factories are far too small to be financially
attractive for cogeneration applications.
Country Rice mills Paddy
(10 6 tons)
Indonesia
Malaysia
Philippines
Thailand
Viet Nam
>78,000
380
>13,000
17,000
>100,000
1.8.2 Sugar industry
Table 1.6 Status of rice industry in ASEAN
49.7
2.2
10.5
33.8
24.9
Rice husk
(10 6 tons)
10.94
47.0
2.32
7.45
5.49
Generation
potential
(GWh/year)
5,472
237
1,160
3,725
2,746
Milling
capacity
(>5 tph)
0
62
71
78
55
Generation
capacity
(MW)
0
28
68
61
66
In most sugar mills, bagasse generated as residue is utilized for heat and power generation.
There are over 150 sugar mills in the ASEAN, producing close to 35 million tons of bagasse
annually. A little less than one-third of the raw sugar cane is turned into bagasse. Processing
one ton of sugarcane will generate an average of 300 kg of bagasse. Assuming that bagasse
is consumed efficiently, 3 kg of bagasse is necessary to produce a kWh of electricity. Based
on this, the technical potential for power generation from bagasse in ASEAN can be estimated
at 11,600 GWh/year (see Table 1.7). However, the existing equipment in most facilities is old
and inefficient, often resulting in the generation of low-pressure steam. There is a need for
adopting boilers of higher capacities and pressures greater than 40 bar.
Country Sugar
mills
Indonesia
Malaysia
Philippines
Thailand
Viet Nam
Table 1.7 Status of sugar industry in ASEAN
67
N.A.
36
46
16
1.8.3 Palm oil industry
Sugarcane
(10 6 tons)
29.05
N.A.
18.50
57.97
11.29
Bagasse
(10 6 tons)
8.72
N.A.
5.55
17.39
3.39
Generation
potential
(GWh/year)
2,906
N.A.
1,777
5,797
1,129
Generating
capacity
(MW)
792
N.A.
758
1,871
54
In a palm oil industry, as much as 70 per cent of the fresh fruit bunches (FFB) are turned into
wastes such as empty bunches (23 per cent), fibres and shells (19 per cent), while between
600 and 700 kg of liquid effluent are produced per ton of FFB. Though many palm oil mills
generate combined heat and power from fibres and shells, the use of palm oil residues could
still be optimized. Fibres and shells generated by a ton of FFB can produce approximately 45
kWh; empty bunches could contribute to another 35 kWh of electricity generation.