**3. Oil extraction methodologies and outcomes from non-edible plant sources**

## **3.1 Oil extraction**

After shelling, drying and pulverizing with a grinder (Xiantaopai XTP-10000A, Zhejiang, China) the seeds were processed for extraction. The oil extraction from

*Optimization and Characterization of Novel and Non-Edible Seed Oil Sources for Biodiesel… DOI: http://dx.doi.org/10.5772/intechopen.97496*

*Acacia farnesiana, Albizzia julibrissin, Rhus typhina* and *Koelreuteria paniculata* was carried by Soxhlet (chemical; 90°C for 7 h using different solvents; **Figure 5A**) and mechanical extraction of by two different electric oil expeller machines comprising Fangtai Shibayoufang FL-S2017 China (less power extractor) and Fangtai Shibayoufang J508, China (high power extractor), (**Figure 5B**). Pre-treatment of seed is essential for mechanical and Soxhlet extraction, which can increase the amount of oil recovery. After 2–3 revolutions, a considerable yield of crude seed oil was obtained. The oil removed from the seed by mechanical presses requires additional handling of extraction and filtration to produce a purer raw feedstock. Further following steps were conducted to get the biodiesel from these sources comprising filtration, rotary evaporation for access methanol, heating, transesterification, settling, separation, and washing.

The oil production was calculated by the following equation.

Conversion% Obtained seed oil weight g / Tot = ( ) al seed weight g 100 ( )× (1)

The comparative oil content (%) of 4 plants, obtained by using mechanical oil extraction and Soxhlet extraction methods from four plant sources is given in **Table 1**.
