Biomass Energy Using Methane and Hydrogen from Waste Materials - Topical Themes in Energy and Resources - page 149

Fig. 8.18 Flow diagram of Yagi bio-ecology centre

Table 8.10 Characteristics of the biomass resource at YBEC
Item Manure from 650 dairy cattle Manure from

1500 pigs

Tofu reuse

Raw manure Dewatered liquid

Total Solids mg/L 136,700 47,500 65,700 233,000

VTS mg/L 115,000 37,500 55,000 220,600

Suspended Solids mg/L 89,000 34,500 44,500 24,850

BOD mg/L 24,000 6500 25,500 840,000

COD Cr mg/L 130,000 64,000 82,000 7

pH 7 7 6 7290

Total N mg/L 5530 1950 4370 2400

NH 4 + N mg/L 2500 1200 4900 1698

Total P mg/L 1290 395 1470 -

every year (comprised of 25,171 t of livestock waste and 4827 t of food waste in
2004). 65 % of the biomass is treated by anaerobic digesters; as shown in Fig. 8.18 ,
the animal and food wastes are mixed in the storage tank, and then fed either to a
mesophilic digester (volume of 2100 m 3 at 37 ºC) or a pilot thermophilic digester
(volume of 600 m 3 at 55 ºC). The hydraulic retention time and treatment capacity
are 33 days and 62.8 t/day for the mesophilic digester, and 26 days and 23.2 t/day
for the thermophilic digester.
Biomass characteristics are summarized in Table 8.10 . The average biogas pro-
duction rate for the thermophilic digester is 1.00 Nm 3 /d/m 3 -digester, approximately