The Scientific World Journal / 2013 / Article / Tab 1

Research Article

Emergy Analysis of Biogas Systems Based on Different Raw Materials

Table 1

Energy accounting for BPC system.

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

Local renewable resources
1Underground waterJ Odum, 1996 [16] 0
2Corn strawJ Odum, 1996 [16] 3180

Total (RR) 3180

Renewable purchased inputs
3Human laborJ Xi and Qin, 2006 [17] 5804

Total (RP) 5804

Nonrenewable purchased inputs
4Steel platebUS $ Brown and Ulgiati, 2004 [18] 846
5Equipments, PE pipesbUS $ Brown and Ulgiati, 2004 [18] 5441
6Civil work costbUS $ Xi and Qin, 2006 [17] 605
7Maintenance costUS $ Xi and Qin, 2006 [17] 605
8Coal J Odum, 1996 [16] 2177
9ElectricityJ Xi and Qin, 2006 [17] 1886
10Protein powderUS $ Xi and Qin, 2006 [17] 931

Total (NP) 12491

Total input 21475

System feedback
11Biogas (heated)J Bastianoni and Marchettini, 2000 [15] 7666

Total (F) 7666

Yield
12Biogas (output)J Bastianoni and Marchettini, 2000 [15] 28996
13Nitrogen fertilizerg Zhang et al., 2005 [19] 145
14Phosphate fertilizerg Zhang et al., 2005 [19] 218
15Potash fertilizerg Zhang et al., 2005 [19] 193

Total yield (Y) 29553

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