Study On Pyrolysis Kinetics Characteristics Of Crude Oil In In-situ Combustion Process

With increasing depletion of energy and growing energy needs,further more owing to relatively less oil reserves with a large proportion of heavy oil in China,more attention has been paid to oil extraction technology through fire flooding.While the focus of fire flooding are often on the combustion process,the key effects in pyrolysis process in fire flooding are the controls of combustion process.Because of less-studies of the complex process of combustion and pyrolysis respectively in fire flooding,resulting in a not clear understanding of the in situ combustion process and lack of theoretical guidance.In this paper,it choosed Mana and Tarim crude oil as the research object,using thermal gravimetric method and method for pyrolysis in reactor to study pyrolysis research.Thermal gravimetric method and method for pyrolysis in reactor?closed and open system respectively?were under linear and constant temperature,investigate factors in fluencing temperature,heating rate,atmosphere and other factors on the performance of pyrolysis oil.The results showed that: the TGA curves under linear heating and air atmosphere show that the pyrolysis oil oxidation process was divided into three stages,namely the low temperature oxidation,pyrolysis,high-temperature oxidation.The pyrolysis process in a nitrogen atmosphere under linear heating was divided into two phases,namely the low tem-perature gasification and high temperature pyrolysis.Four components of pyrolysis reactions were concentrated in a temperature range,the order of SARS pyrolysis conversion rate peak was: saturates<aromatics<resin<asphaltenes.The gas production rate inceased before it was reduced as the reaction temperature and reaction time increased.The maximum gas yield of crude oil in closed system of reaction kettle was at 450? and 15h;the rate decreased and gas production trends to stabilize exceed 15 h.The components methane gas content generally upward trend as reaction time in reaction open system under different tempetatures,explained that the degree of solution heat oil is deepened.As the temperature increases,the proportion of gas components of C1,C2 was the largest.Three analytical dynamic equations were used to fitting two stages of linear temperature pyrolysis of crude oil under nitrogen atmosphere.It determined the suitable mechanism function and the pyrolysis kinetic parameters were obtained.By crude chemical dynamics simulations and calibrates in a closed system pyrolysis reaction at different reaction times,it found that crude oil in the activation energy within the range of 80 kJ·mol^-1-270kJ·mol^-1,when the pyrolysis reaction was regarded as 20 first order parallel reaction,the theoretical and experimental values of pyrolysis simulation on high degree of agreement.It showed that the establishment of model simulations was in a good process reliability.