Kinetics of Thermal Decomposition of Tar in the Presence of Air and Nitrogen Gas

Abstract

Thermogravimetric analysis (TGA) provides useful information, which can be used in thermal processing and conversion kinetic modeling of materials, including hydrocarbons. In the present study, a series of TGA experiments were conducted in the presence of air (combustion) and under inert conditions (pyrolysis) using nitrogen gas with the focus of obtaining quantitative information to compare thermal decomposition characteristics of the two processes. The analysis was performed at different gas injection rates (10–50 mL/min) and heating rates (10–30 °C/min) under non-isothermal conditions from 30 to 600 °C. It was observed that the gas injection rates did not have significant impact on the thermal decomposition of the tar sample. However, increasing the heating rate shifted the peak temperatures of the reactions to higher temperatures. In addition, the combustion process generally has a higher conversion and peak rate of conversion than the pyrolysis process. Moreover, the activation energy, E a (kJ mol–1), obtained for the combustion process was observed to be higher than those of the pyrolysis.

Kinetic and thermodynamic modelling of thermal decomposition of bitumen under high pressure enhanced with simulated annealing and artificial intelligence

“…During thermal decomposition of hydrocarbons including bitumen, several thermochemical processes involving bond breaking and forming, such as vaporization, combustion, oxidative decomposition of carbonaceous organic component, and pyrolysis, take place. [ 11 ] Thus, multiple stages of reactions, which is indicative of existence of the mentioned processes, can be observed from each curve. However, at each heating rate, it shows that the weight loss decreases as the total pressure of the system increases.…”

“…The kinetic parameters were obtained using the Arrhenius based method (by solving Equations ( 5) and ( 6)) as presented in our previous studies. [1,9,11] Then, after introducing β in Equation ( 5) and discretizing, Equations ( 12) and ( 13) are obtained as follows:…”

“…[3,9] Accordingly, significant number of investigations have been carried out on the TGA of heavy oil resources under atmospheric pressure. [4,9,[11][12][13][14] However, in some cases, heavy oil may exist under pressure in the reservoir. [15,16] Hence, there is the need to obtain TGA parameters under high pressure to expand the applicability.…”

A Critical Review of Reservoir Simulation Applications in Key Thermal Recovery Processes: Lessons, Opportunities, and Challenges

“…Yang et al in 2017 constructed a combustion simulation model to match the results of RTO experiment testing combustion reactions between injected air and poststeam oil, which could provide insight into the performance of future pilots . Alade et al (2019) investigated the changes in oil composition under combustion and a pyrolysis process (nitrogen gas injection) and concluded that combustion resulted in a higher conversion rate . Xu et al (2016) reported the impacts of in situ combustion on pore configurations and permeability .…”

Mass and Heat Transfer of Thermochemical Fluids in a Fractured Porous Medium

“…Tar residue can cause severe damage in water injection and oil production wells. Alade et al [ 14 ] used thermochemical treatments to remove tar damage, showing that pressure and heat generated due to thermochemical reactions improved tar emulsification and mobilized tar to the surface at a low viscosity. In addition, the authors used the same concept to remove damage due to various organic scales, such as asphaltene and emulsion blockage, in different conditions [ 15 ].…”