# Pollutant Emissions and Combustion Efficiency Assessment of Engines Using Biodiesel
## 2 Materials and Methods
### Methodology for Experimental Tests in Electric Generator  
This test describes the experimental methodology of polluting emissions and combustion efficiency in an electric generator. These experimental tests were carried out under the following procedure: the Fluke electrical network analyzer was installed near the output connection of the electric generator (the connection was three-phase), with the aim of measuring the three phases of the electric generator. Subsequently, the BACHARACH(r) PCA 400 exhaust gas analyzer was installed according to the manufacturer's specifications (see Figure 4). Drastic industrial safety measures were taken due to the industrial-grade equipment that was handled in this study.  
The blends B0, B5, B10, B15, B20, and B25, which were taken for experimental tests, are observed in Figure 5. An important fact to mention is that no blends were made at more than 25% because, in a previous test (low-power single-cylinder engine) on the B20 mixture, the polluting emissions values were considerably increased. In this case, it has limited the blend to a maximum B25 so as not to affect the equipment.  
Figure 6 shows the containers where each one contains 10 L per blend for experimental tests. With this amount of fuel, the electric generator is kept on for an average time of 30 min. In addition, the electrical power of 6772.8 kW was kept constant; with this load, all emission tests were performed for blends B0, B5, B10, B15, B20, and B25.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**MOTOR** & \\ \hline Engine Brand & Thunder® VANS \\ Engine Power & 67.00 HP \\ Displacement & 4100.00 cc \\ Ignition & Electric 24 VCD 5 kW \\ Engine Type & Diesel \\ Engine strokes & 4 \\ Engine RPM & 1800 RPM \\ Fuel Tank Capacity & 150 L \\ Recommended Oil & SAE 15 W/40 (Included) \\ Oil Filter & Included \\ Oil Capacity & 11 L \\ Oil Sensor & Included \\ Maximum Power—Generator: & 33.3 kW \\ Nominal Power—Generator: & 30 kW \\ Voltage & 240/120 VCA \\ \hline \hline \end{tabular}
\end{table}
Table 2: Technical characteristics of the electric generator.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Properties** & **Diesel** & **Biodiesel** \\ \hline Norm & ASTM D975 & ASTM PS 121 \\ Kinetic viscosity at 40 \({}^{\circ}\)C & 1.3–4.1 & 1.9–6 \\ Specific gravity at 15.55 \({}^{\circ}\)C & 0.85 & 0.88 \\ Density (lb/gal) & 7.079 & 7.328 \\ Carbon \% & 87 & 77 \\ Hydrogen \% & 13 & 12 \\ Oxygen \% & 0 & 11 \\ Sulfur \% & 0.05 & 0.0024 \\ Flash point (\({}^{\circ}\)C) & 60–80 & 100–170 \\ Cetane number & \(-\)35 to \(-\)15 & \(-\)15 to 10 \\ Stoichiometric ratio & 40–55 & 48–65 \\ (air/fuel) & \\ \hline \hline \end{tabular}
\end{table}
Table 3: Properties of diesel and biofuel for analytical combustion analysis [30].  
Figure 4: Connection of the network and exhaust gas analyzer.  
Figure 5: Biodiesel blends.  
Figure 6: Experimental emissions tests in an electric generator.  
As a complementary analysis, an analytical study of combustion emission volumes and experimental thermography tests of the combustion process were carried out. The methodology used is described below.