Research Article

Extraction of Municipal Sewage Sludge Lipids Using Supercritical CO2 for Biodiesel Production: Mathematical and Kinetics Modeling

Table 3

Physicochemical properties of ScCO2 extracted lipids from municipal sewage sludge (MSS) and sewage sludge biodiesel.

PropertiesUnitLipidsBiodieselASTM D6751EN 14214

Yield%26.54 ± 0.2184 ± 2
FFAs%0.81 ± 0.160.16 ± 0.06
Kinematic viscosity at 40 ℃mm2/s6.18 ± 0.214.10 ± 0.141.9–6.03.5–5.0
Density at 15 ℃kg/m3840 ± 6865 ± 4880860–900
Saponification valuemgKOH/g196 ± 2.54158 ± 2.54
Acid valuemgKOH/g0.50 ± 0.040.20 ± 0.02≤0.5≤0.5
Heating valueMJ/kg39.20 ± 1.439.64 ± 2.86
Cetane number56.10 ± 2.756 ± 2≥47≥51
Pour point8.5 ± 0.5−10.50 ± 0.65−15 to 16
Cloud point12.5 ± 0.5−2.50 ± 0.14−3 to 12
Heating valueMJ/kg39.20 ± 1.439.64 ± 2.86
Iodine numberg I2/100 g69.10 ± 2.8075.9 ± 2.34≤120
Flash point166 ± 2.10140 ± 4≥130≥101