Laboratory Studies On Oxidation Stability Of Biodiesel

All is known that oil is Non-renewable. To search for new alternative energy sources is an urgent need. Biodiesel is renewable and friendly to environment, particularly with the equal combustion value to petroleum diesel.More and more countries are striving to develop, promote bio-diesel production and use.Because of using different types of raw materials and processing technology,various biodiesel has significantly different from other kinds. unsaturated biodiesel made from animal and vegetable oils is easily oxidized, and it has poor stability. Tung oil is an important dry oil, rich in China, annual output accounting for 75% of the world's total output, Because tung oil has abundant feedstock,it has a great advangtage to made for biodiesel. But its highly unsaturated affect the oxidation stability of biodiesel.This experiment consists of two parts:the first part of the experiment adopted the method of accelerated oxidation of the tung oil biodiesel (TME), and their respective and mixture of 0# diesel oil, palm oil biodiesel (PME).In the different, conditions,like water, oxygen, metals and different antioxidants, we study the performance parameters of regular sample of the oxidized oil,which contains peroxide value, acid number and kinematic viscosity (40℃), And study the influence on the oxidation stability of these factors,we finally select the suitable antioxidants by this experiment. The second part of the experiment, store the oil samples for 13 weeks which mixed in different proportions about TME with 0# diesel oil and TME with PME. According the periodic sample, measured peroxide value, acid number and kinematic viscosity (40℃),under these conditions, analyze the oxidation stability' and to choose the best storage conditions.As is shown that in all factors, water and the flow rate of oxygen are more influential on the oxidation stability of biodiesel; By comparion, copper influence on oxidation stability of a larger, but the iron can effectively reduce the effects. This four antioxidants can slow the oxidation to some extent, it is clear that BHA can effectively inhibit the oxidation of biodiesel, TBHQ and V-C sodium the less, the worst is the tea polyphenols. At the same time,we found that the mixed oil—TME with diesel oil—can reduce the peroxide value, acid number and kinematic viscosity, and improve its oxidation stability; When TME and PME mixed with each other, it become has good oxidation stability, this is because the reduction of double bonds in the polymer reduces the formation of mixed oil, and so avoid its adverse effects on the engine. PME reduced the viscosity of the oil while it also ensured the adequate lubrication performance, the mix are fully capable in place of 0# diesel oil to some extent.It is also found from the experiment that in the four conditions above, for the storage of oil, non-sunlight and non-air are the most favorable for storing biodiesel; about the four ratio of oil mixture, the oxidation stability of TME with petrochemical diesel is the best.