The effects of metallic catalysts on light crude oil oxidation in limestone medium

In this study, 28 experiments were performed to study the effects of metallic additives on light crude oil oxidation in limestone medium. Karakus and Beykan crude oils from Turkish oil fields were used. The metallic additives were ferric chloride (FeCl3) copper chloride (CuCl) and magnesium chloride (MgCl(2)(.)6H(2)O). The mixture of aqueous solutions of three metallic salts with limestone and the crude oils was subjected to a controlled heating schedule under a constant flow rate of air. The produced gas was analysed for its oxygen and carbon oxides contents. The results of reaction kinetics showed that the molar CO2/CO ratio values of fuel combustion increased when additives were added. A decrease in the atomic H/C ratio with an increase in temperature was observed for all runs. The reaction order, m in Arrhenius equation increases as concentration of copper and magnesium chloride additive increases but decreases as ferric chloride additive increases in both crude oils. It is observed that the metallic additives except ferric chloride decreased the Arrhenius constant, Ar, for both crude oils. As concentration of ferric chloride increases the activation energy of Karakus crude oil increases while activation energy of Beykan crude oil decreases. The copper chloride additive shows same trend for both crude oils. The 1.0 mol% concentration decreases the activation energies. The 2.0 mol% magnesium chloride increases the activation energy of Karaku crude oil while decreases the activation energy of Beykan crude oil more than 1.0 mol% does. For Karaku crude oil, the oxygen consumption curves of 2.0 mol% of metallic additives show one peak. There is similar behavior between runs with 1.0 mol% of ferric chloride and magnesium chloride and runs with no additive, but the oxidation reaction peaks with metallic salts at both concentrations occurs at lower temperatures. For Beykan crude oil, all the additives lower the peak temperature when they are compared to standard run. The trends of the curves are actually the same. Copper chloride shows one peak with the 1.0 and 2.0 mol% runs for both crude oils. (C) 2002 Elsevier Science B.V. All rights reserved.