Improvement of the low-temperature properties of vegetable oils
Stefan Ptak, Wojciech Krasodomski, Artur Antosz, Magdalena Żółty
Streszczenie
The development of bio-components, as alternative components of lubricants, is increasingly important in relation to the limited resources of crude oil and the growing care of the environment. Most lubricants used now are produced with the use of hydrocarbon base oils, originating from the crude oil processing. They create a notable ecological hazard. To eliminate this hazard, there is a strong pressure on the development and introduction into use of lubricants for various biodegradable applications. The paper presents studies on the obtaining of modified vegetable oils, which are characterised by their improved lowtemperature properties, in view of their application as the base oils. Four different vegetable oils were solvent dewaxed by a mixture of methyl ethyl ketone - toluene solvents (MEK-TOL) under similar process conditions as those used during the solvent dewaxing, used for the oil dewaxing and slack waxes of petroleum origin de-oiling in industrial refinery plants. It has been found that this process allows for an important improvement in the low-temperature properties of vegetable oils, and in particular for the lowering of the cloud, pour, and solidification points. The modification of vegetable oils is related to a change in the fatty acids profile. A clear increase in the content of saturated acid glycerides was observed in the precipitated deposit, as compared with the filtrate (modified vegetable oil), which confirmed the selectivity of the dewaxing process. The conducted studies have shown a possibility of the effective application of a classical dewaxing process to improve the low-temperature properties of an atypical raw material, such as vegetable materials.