The Scientific World Journal / 2013 / Article / Tab 2

Research Article

Emergy Analysis of Biogas Systems Based on Different Raw Materials

Table 2

Energy accounting for BPF system.

No.ItemaUnitsRaw dateTransformityReferencesSolar emergyEm
(sej/unit)(sej/yr)($)

Local renewable resources
1Sunlight J Odum, 1996 [16] 0
2Solid manureJ Odum, 1996 [16] 0
3Feces J Odum, 1996 [16] 0

Total (RR)     0

Renewable purchased inputs
4Human laborJ Xi and Qin, 2006 [17] 4353

 Total (RP)     4353

Nonrenewable purchased inputs
5Civil work costbUS $ Xi and Qin, 2006 [17] 2963
6Equipments, PE pipesbUS $ Xi and Qin, 2006 [17] 5200
7Appurtenant workbUS $ Xi and Qin, 2006 [17] 713
8Maintenance costUS $ Xi and Qin, 2006 [17] 605
9Coal J Odum, 1996 [16] 738
10ElectricityJ Xi and Qin, 2006 [17] 1173

Total (NP)     11391

Total input    15744

System feedback
11Biogas (heated)J Bastianoni and Marchettini, 2000 [15] 13881

Total (F)     13881

Yield
12Biogas (output)J Bastianoni and Marchettini, 2000 [15] 28561
13Nitrogen fertilizerg Zhang et al., 2005 [19] 1838
14Phosphate fertilizerg Zhang et al., 2005 [19] 6844
15Potash fertilizerg Zhang et al., 2005 [19] 6796

Total yield (Y)      44039

aLocal nonrenewable resources can be neglected.
bItems have been divided by a lifetime of 20 years.