Catalytic Effect of Heavy Metal Oxides on Crude Oil Combustion

Abstract

Crude oil combustion was studied in the presence of titanium, ferric, nickel, cupric, vanadium and chromium oxides. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were applied to the crude oil combustion in the presence and absence of the metal oxides. It was found that the effect of titanium oxide was similar to that of silica and alumina. The fractional amount of heat released in the lower temperature region increased with increasing quantities of the titanium oxide and attained a maximum level. The coke combustion peak shifted slightly to the lower temperature region and peak shifted slightly to the lower temperature region and became smaller. Vanadium, nickel and ferric oxide behaved similarly in enhancing the endothermic reactions. The effect of a small amount of metal oxides (about 1% by weight) on the crude oil combustion in the presence of silica powder was insignificant. However, the same amount of metal oxide affected the DSC curves produced from the combustion of the crude oil/sand mixture significantly. It appears that, in the presence of the large surface area such as silica, the surface reactions are predominant and unaffected by the small amount of the metal oxide present.

Kinetic Study of Catalytic In-situ Combustion Processes in the Presence of Nanoparticles

“…It has been confirmed by several authors that in an ISC process mainly three oxidation regions occur at different temperature levels, namely, low temperature oxidation (LTO), fuel deposition (FD), and high temperature oxidation (HTO) (Drici and Vossoughi, 1987;Kisler and Shalcross, 1996;Kok, 2002). LTO reactions involve heterogeneous gas/liquid reactions that mainly produce alcohols, ketones, peracids, aldehydes, and peroxides (Kamal and Verkoczy, 1986).…”

“…Lower AE means lower energy needed to initiate an oxidation reaction. Drici and Vossoughi (1987) applied thermal analysis techniques to study how metallic additives promote ISC reactions. They observed lower AE in crude oil mixtures with a higher ratio of surface area.…”

Combustion Front Behavior in Porous Media With Catalytic Agents

“…In general, this has been attributed to changes in morphology and surface properties of the porous medium ahead of the combustion region. Effects of these changes on in-situ combustion are interpreted as of socalled dual nature [8][9][10]. The materials:…”

“…However, Reference [8] showed that consideration of the changes in the energy alone can be misleading; instead, combined (compensation) effect of the frequency factor and activation energy of a reaction should be considered throughout an investigation. Here, we consider a normal (m>0) compensation effect for the HTO and LTO reactions i.e, the frequency factor and activation energy relationship of the oxidation reactions follows a positive trend, in the presence of catalytic agents: c mE k + = log …… (5) where m=6.453E-5 kmole/kJ is given in [8] and valid in the presence of various metal oxides and c= -2.38 is taken here so that the base-state values of activation energies and frequency factors are recovered using equation (5). Figure 4 also shows the compensation corresponding to Case 8 in terms of the changes in temperatures, propagation velocities and separation distances of the reaction regions.…”

“…The LTO region, on the other hand, involves heterogeneous gas/liquid reactions producing partially oxygenated compounds in addition to the bond scission reactions [1,2]. Reactions in the latter are often considered to be responsible for depositing fuel necessary for the reactions in the HTO region [1,8]. Thus, briefly speaking, …”