Research Of Improving Oxidative Stability Of Diesel Oil

Over a hundred million ton diesel oil is consumed every year in China, above 30 percent of which is FCC diesel oil. So the oxidative stability of diesel oil becomes a very important problem. Production cost will be increased if refining technologies only were used to improve its oxidative stability. So in this paper used antioxidants were used to improve the oxidative stability of diesel oil. Two new-style antioxidants FG and AG were synthesized by inducting the group which has the function of peroxide decomposed reagent to the traditional phenolic and amine antioxidant. And the best synthesis conditions of the antioxidants were decided by using orthogonal experiment design. The target products were characterized by IR. The performance of the two antioxidants were investigated, and the results of experiments showed: The antioxidant effects of FG and AG are better than the chemicals in combination which are compounded by 2,6-di-tertbutyl-4-methylphenol or triethylamine and Phosphorous antioxidants(peroxide decomposed reagent) at the molar ratio of 1 to 1. This indicates that the suppose of inducting the group which has the function of peroxide decomposed reagent to the traditional phenolic and amine antioxidant is successful, and this provides a viable method of synthesizing of new-style antioxidants; The antioxidant effects will be better if AG and FG are compounded at the molar ratio of 1.5 to 1;Adding antioxidants to the experimental diesel oil after caustic washing by diluted sodium hydroxide solution can effectively improve its oxidative stability, and the sodium hydroxide solution after caustic washing can be used circularly. It could be a good method to improve the quality of diesel oil for the refining enterprises which have no hydrofining unit or no enough hydrofining capacity, in order to increase its production agility and economic effect. In period of time, it has no effect to the antioxidant effects of FG and AG at different antioxidants adding time; It also not be effected by minim water in diesel oil even 1 percent of water, and has no bad effects to other main physical performance of diesel oil.