Evaluation of the Formation of Gum in Gasolinas "Tipo C" Under Multiple Action of Metals Fe, Ni and Cu Using Factorial Planning
Multi-scale and/or multi-disciplinary approach to process-product innovation
Analysis of Energy-Environmental Issues (T3-3P)
Keywords: Factorial planning, Gasoline, Gum, Metals
The composition of the gasoline presents composed as, the olefines, aromatic and nitrogenates that introduce a certain degree of instability to the product. The nature and the amount of deposits formed in automotive motors possess direct relationship with this instability, that has as consequence the gum formation resulting from the olefines oxidation, mainly. This comes as a resinous material that, in the initial apprenticeship, it can stay in solution, but later it tends to precipitate through new chemical reactions, happening like this deposits in the system of admission of the motor, what can cart from tuning problems to imprisonment of the stems of the valves. Several factors contribute to accelerate the gum formation, just as increase in the temperature, the time of storage and also the presence of ions of metals, that they are responsible for the catalytic activity. The ions of the metals, particularly those of the transition metals (copper, lead, iron etc.), they can have deep effect in the tax of the oxidation of the hydrocarbons.
This work evaluates the influence of the simultaneous presence of the metals, Ni, Cu and Fe, some of the main components of the tanks for stockpiling of fuels, in the process of gum formation. For the accomplishment of the rehearsals a quadratic experimental planning was elaborated, of the type 24, with 05 experiments in the central composition with axial configuration. The entrance variables used were: concentration of the 03 metals, in ppb, and the time of stockpiling, in days. The accomplished tests involved different concentrations of metals, 25, 150, 275, 400 and 525. The time of stockpiling followed the same procedure, with values of 01, 16, 31, 46 and 61. In the experimental procedure the method was used ASTM D 381 for the determination of the gum tenor.
The evaluation of the surfaces of answers allowed to identify the simultaneous contribution of the concentrations of the metals and of the time of stockpiling. With this analysis it was verified that the nickel concentration went little significant for the process of gum formation, while the metals copper and iron contributed potentially. Besides, the interactions of these metallic ions in the gasoline elevated plenty the gum formation in one time relatively short of stockpiling.
The obtained results are compatible with published them in the literature, where the metals copper and iron are analyzed individually and they present intense catalytic activity and potentiating the oxidation reaction with the gum formation. With this study it is possible to evaluate that it sorts out the composition of the steels of the tanks of fuels can influence in this process.
Presented Tuesday 18, 13:30 to 15:00, in session Analysis of Energy-Environmental Issues (T3-3P).
