Abstract:

Sindora glabra is an indigenous species in Hainan island, characterized by its exudation of oleoresin. To provide the techniques and references for exploring the oleoresin utilization for fuel oil, six oleoresin samples were extracted during Sept to Dec. in 2009 by perforating the trunk of S. glabra from three main populations. Physical and chemical properties of the oleoresin and their relationships were analyzed with 16 measured indicators. The result showed that eight indicators, such as solidifying point, flash point, boiling process, gross heat, net heat, iodine value, sulphur content and copper strip corrosion, were relatively stable, the first seven indicators varied ranging between -27 and -36 ℃, 114 and 124 ℃, 248 and 345 ℃, 42 and 43 MJ·kg^-1,40 and 41 MJ·kg^-1, 118 and 131 gI₂·(100 g)^-1, 0.000 5% and 0.009 3%, respectively, with copper strip corrosion all same of I_a, indicating slight variation of those indicators among oleoresin samples. However, there were significant differences (P<0.01) in density, kinematic viscosity, cold filter plugging point, water content, ash, impurities, acid, carbon residue and cetane index among those oleoresin samples, varying from 812 to 957 kg·m^-3, 24 to 48 mm²·s^-1, 12 to 28 ℃, 0.03 to 2.74%, 0.008% to 0.055%, 0 to 0.060%, 0.35 to 2.23 mgKOH·g^-1, 0.42% to 5.46% and 25-64, respectively, suggesting there were close relationships among oleoresin samples from different trees. Carbon residue was significantly negatively correlated with flash point (P<0.01), but positively correlated with iodine value, ash, cold filter plugging point (P<0.05). Density was positively correlated with kinematic viscosity and impurities (P<0.01), but negatively correlated with cetane index (P<0.05). Density and carbon residue were the two most important indicators in evaluating physical and chemical properties. In general, the oleoresin had low mobility in low temperature, low spray evaporation, as well as low oxidation stability, but possessed advantages of good engine performance, cleanness, corrosion resistance and renewability, therefore it could be explored as one kind of diesel fuel.

Key words: Sindora glabra, oleoresin, diesel, physical and chemical properties