Animal Biomass
Although biomass is often interpreted as vegetable biomass, animal-derived biomass remains an energy source that should not be totally ignored, even if its production is largely determined by developments in the agricultural and food sector. In order to provide an idea of the volumes involved, it should be noted that the annual production of waste by poultry is 8 kg/head. Pigs produce about 300 kg/y, beef cattle 900-1200 kg/y, and dairy cattle 1200-2000 kg/y (Smil 2001).
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Table 4-12 Properties of Various Biomasses |
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Biomass |
HHV MJ/kg |
Moisture wt% |
Ash wt% |
Sulfur wt% dry |
Chlorine wt% dry |
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Charcoal |
25-32 |
1-10 |
0.5-6 |
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Wood |
10-20 |
10-60 |
0.25-1.7 |
0.01 |
0.01 |
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Coconut shell |
18-19 |
8-10 |
1-4 |
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Straw |
14-16 |
10 |
4-5 |
0.07 |
0.49 |
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Ground nut shells |
17 |
2-3 |
10 |
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Coffee husks |
i6 |
10 |
0.6 |
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Cotton residues |
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(stalks) |
16 |
10-20 |
0.1 |
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Cocoa husks |
13-16 |
7-9 |
7-14 |
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Palm oil residues |
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(shells) |
15 |
15 |
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Rice husk |
13-14 |
9-15 |
15-20 |
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Soya straw |
15-16 |
8-9 |
5-6 |
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Cotton residue |
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(gin trash) |
14 |
9 |
12 |
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Maize (stalk) |
13-15 |
10-20 |
2 (3-7) |
0.05 |
1.48 |
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Palm oil residues |
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(fibers) |
11 |
40 |
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Sawdust |
11.3 |
35 |
2 |
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Bagasse |
8-10 |
40-60 |
1-4 |
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Palm oil residues |
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(fruit stems) |
5 |
63 |
5 |
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Source: Derived from Arbon 2002; Quaak, Knoef and Stas sen 1999 |
In the SCGP coal gasifier in the Nuon plant in Buggenum in The Netherlands, trials have been carried out with the gasification of mixtures of coal with up to 12% poultry litter and/or municipal sewage sludge. There are plans to gasify up to 30% non-coal feedstocks in 2004 (Kanaar and Wolters 2002). It should be mentioned that the percentages of alternative feedstocks are generally given as a mass percentage. As an energy percentage, these figures are at least 50% lower.
Abattoir waste has also been со-gasified in the Puertollano plant up to an amount of 4.5% of total feed. The meat and bone meal that is classified as a risk material was divided into specific risk material (SRM), consisting of spinal marrow, bones, intestines, spleen, or brain, and high risk material (HRM), which is other parts of the animals, and blood material. When this material was fed as 4.5% of the total feed, the high chlorine content made itself noticeable in an increased chloride level in the
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Table 4-13 Analysis of Typical Biomass |
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Proximate Analysis |
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Volatile matter, wt% maf |
>70 |
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Ash, wt% ar |
1.5 |
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Moisture, wt% ar |
20 |
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Fixed carbon, wt% ar |
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Ultimate analysis |
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C, wt% |
54.7 |
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H, wt% |
6.0 |
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O, wt% |
38.9 |
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N, wt% |
0.3 |
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S, v |
0.1 |
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Table 4-14 Ash Components in Various Biomasses as Wt% of Total Ash
Source: Klensch 2001 |
syngas scrubber (Schellberg and Pena 2002). Some typical properties of animal biomass are given in Table 4-15.