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Metal tallates are generating a considerable interest as catalysts for thermaly enhanced oil recovery. Meanwhile, In-situ combustion is considered a promising thermally enhanced oil recovery method, it is still viewed as a complicated process due to its multiphasic, multicomponent and multistep reactions occurring within it. In this study we investigated the impact of Mn@Cu tallate on heavy oil oxidation process in order to highlight its effect on stabilizing combustion front using differential scanning calorimetry combined with isoconversional principle for calculating the kinetic parameters of the process. The obtained data have showed that Mn@Cu tallate can play an important role in stabilizing combustion front of in-situ combustion where it decreased the energy of activation of low temperature (LTO) and high temperature oxidation (HTO) regions. As a result, the effective reaction rate constants in both regions increased respectively as well.

In this research, combustion behaviour of three crude oils with different °API gravities was analysed. The thermogravimetric analyser (TGA) and differential scanning calorimeter (DSC) experiments were performed using three different heating rates (2, 5, and 10 °C min−1) under air atmosphere. The reaction regions, burn-out temperatures, and peak temperatures were determined accordingly. Two main reaction regions, particularly the low-temperature oxidation (LTO) and high-temperature oxidation (HTO) reactions, were figured out in TGA and DSC curves, which suggested exothermic behaviour. Kinetic parameters of the crude oils were determined using model free methods (Ozawa–Flynn–Wall, OFW, and Kissinger–Akahira–Sunose, KAS), which allows the calculation of kinetic properties at progressive conversion degrees without the requirement of any reaction models and f(α) estimations. The variation in activation energy with respect to the conversion degree pointed out that the LTO reaction stage can be subdivided into three subzones. The results indicated that the activation energies were changing depending on the conversion degree, which is an indication of complex reaction mechanisms. The change in activation energy with respect to conversion degree showed slight variation for heavy crude oil compared with that in light crude oil.

In this research, the effect of different clay minerals (bentonite, illite and kaolinite) on the combustion behavior and kinetics of crude oils from Kazan region (Russia) was studied using thermogravimetry (TGA) and differential scanning calorimeter (DSC). The ramped temperature experiments were performed at constant heating rates (10, 20 and 30 °C/min) under air atmosphere. In both TGA and DSC experiments, two reaction zones were identified known as low temperature oxidation (LTO) and high temperature oxidation (HTO). The reaction regions, burn-out temperatures, mass loss, heat of reaction and peak temperatures were determined. It was observed that the reaction intervals and the peak temperatures were also affected in the presence of different clay minerals. Kinetic parameters were calculated by Ozawa-Flynn-Wall (OFW), Kissenger-Akahira-Sunouse (KAS) kinetic methods. The addition of different clay minerals reduced the mass loss percentages of the crude oil samples due to the surface area effect. In addition, all clay samples show a good catalytic effect by a significant reduction in activation energy.

In this research, the effect of inlet pressure on combustion behavior of medium and light crude oils was analyzed with TGA and DSC experiments. The ramped temperature combustion experiments were performed at constant heating rates under air atmosphere. TGA curves revealed three main reaction regions known as low temperature oxidation (LTO), fuel deposition (FD), and high temperature oxidation (HTO). In DSC curves, at the early stage of the heating, distillation region was also observed in addition to LTO and HTO reaction regions. It was observed that the changes in inlet pressure affect the temperature intervals of the reaction regions and peak temperatures. The kinetic parameters were calculated according to Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), and ASTM methods. Results indicated that the increase in inlet pressure increased in the activation energy.

This research was focused on the combustion kinetics and oxidation mechanisms of light crude oils in limestone and sandstone matrices. Similarity of the TGA-DTA curves was produced for different crude oils + limestone or sandstone mixtures indicates that the crude oil undergoes three major transitions, known as low-temperature oxidation, fuel deposition, and high-temperature oxidation when subjected to an oxidizing and constant rate environment. Kinetic analysis of the low- and high-temperature oxidation regions was performed using the ASTM and Arrhenius kinetic methods. In reaction mechanism of the combustion reactions, oxidation mechanisms, and rate-controlling steps of fluid-solid reactions in limestone matrix was also determined. It was observed that the linear behavior at elevated temperatures justifies the assumption that chemical reaction was the controlling step.

In this research, the effect of heating rate and different clay concentrations on light and heavy crude oils in limestone matrix was investigated by differential scanning calorimeter (DSC). In DSC experiments, two main distinct reaction regions were identified in all of the crude oil + limestone matrix + catalyst, known as low- and high-temperature oxidation respectively. It was observed that addition of clay to porous matrix significantly affected the thermal characteristics and kinetics of different origin crude oils. The Borchardt and Daniels and ASTM kinetic methods were used to determine the kinetic parameters of the samples. It was observed that activation energies generated for the high-temperature oxidation region for crude oil and crude oil + clay mixtures were in the range of 148–370 kJmol−1 for the Borchardt and Daniels method and 51–253 kJmol−1 for ASTM methods.

In this research, thermal characteristics and model free kinetics of five different °American Petroleum Institute gravity crude oil samples from different locations were studied using combustion calorimetry and thermogravimetry (TGA) techniques. Higher heating values of crude oils were determined from the combustion calorimetry experiments. It was shown that these values increase with an increase in saturate fraction and °API gravity of studied samples and decrease with an increase in viscosity, aromatics fraction, and resin fraction of crude oils. In thermogravimetry, experiments were performed at 10, 20, and 30°C/min heating rates under an air atmosphere. Thermal characteristics of the samples such as reaction intervals and corresponding peak temperatures, mass loss, and residue of the crude oil samples were also determined. Two different model free kinetic methods, known as Ozawa–Flynn–Wall (OFW) and Kissinger–Akahira–Sunose (KAS), were used in order to determine the activation energy values of...

The ramped temperature oxidation experiments were performed on heavy and light crude oil samples using the TGA and DSC instruments. The crude oils were mixed with different weight percentages (10%, 20%, and 30%) of water, as a result of which six different water-oil mixtures were prepared. The samples were heated up to 800 °C with three heating rates 20, 25, 30 °C/min. Two reaction regions, particularly the low temperature oxidation (LTO) and high temperature oxidation (HTO), were identified in TGA and DSC results. The LTO region can be divided into two subzones as before and after around 150 °C. In the first subzone, up to around 150 °C, the endothermic distillation process took place. The results showed that light crude oil and its mixtures had lower reaction starting and ending temperatures, and peak temperatures compared to heavy crude oil and its mixtures. As the water amount in the mixtures were increased, the reaction and peak temperatures shifted to lower temperatures. The kinetic analysis was also performed applying the Ozawa-Flynn-Wall (OFW), Kissenger-Akahira-Sunose (KAS), and ASTM kinetic methods. The activation energies and Arrhenius constants based on the TGA and DSC results were calculated accordingly. The light crude oil and its water mixtures had lower activation energy and Arrhenius constants compared to heavy crude oil and its mixtures. As the amount of water in the mixture was increased, the activation energy and Arrhenius constant decreased, which indicated that the presence of water in the crude oil increases its ability to combust more efficiently.

Thermal decomposition of hydrolyzed lignin is studied in the 300-700eC range in an inert gas atmosphere. The yields of solid, liquid, and gaseous decomposition products are determined. It is demonstrated by combustion calorimetry that the carbonaceous residue of lignin pyrolysis has the highest calorific value. The calorific value of the carbonaceous residue of pyrolysis resin is higher than that of the original lignin. It is shown by thermogravimetry and differential scanning calorimetry with mass spectrometric detection of gases that lignin and its thermal decomposition products could undergo thermolysis with formation of various volatile compounds. Thermal decomposition starts at roughly the same temperature and is 320eC. The loss of sample mass increases in the following sequence: carbonaceous residue < lignin < liquid fraction.

Based on a review of recent foreign publications, we examine the typical features in simulation modeling of in-situ combustion of high-viscosity crude oils and natural bitumens. We pay special attention to phase and kinetics models, and also examine the differences between combustion of heavy and light oils. We formulate approaches and describe important aspects on which we need to focus when comparing models.

A review of recent publications shows rapid development of the in-situ combustion method for the production of high-viscosity crude oils and natural bitumens. Technologies have been developed for application of in-situ combustion after steam-assisted gravity drainage. The use of catalysts is becoming more and more important. We explain the catalytic effect of clays and metals on low-temperature and high-temperature combustion processes.

Features of mathematical modeling of the process of recovery of high-viscosity crude oils and natural bitumens with use of in-situ combustion is examined based on a review of recent foreign publications. Hydrodynamic modeling is increasingly widely used. The importance of physical simulation on a “combustion-tube” apparatus, the results of which are irreplaceable in scaling-up the model to field dimensions, is demonstrated.

This research focused on the characterization and kinetics of Siberian and Tatarstan crude oils by gas chromatography, combustion calorimetry, and thermogravimetry (TG-DTG) techniques. Calorimetric experiments show that crude oil with higher saturate content and low resin fraction has higher heating value. TG-DTG curves indicates that the crude oils undergoes two major transitions when subjected to an oxidizing and constant rate environment known as low- and high-temperature oxidations at each heating rate studied. Kinetic analysis in the low- and high-temperature oxidation regions was performed using model-free methods knows as Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose. Throughout the study, it was observed that the activation energy values of the crude oil samples are varied between 41-72 and 145-198 kJ mol(-1) in low- and high-temperature oxidation regions, respectively.