Study On The Pyrolysis Process And Product Properties Of Liaohe Heavy Oil

The rapid development of the world economy and the rapid growth of oil consumption have promoted people to the development and utilization of heavy oil resources.In order to solve the problem of heavy oil recovery is low,people have begun to introduce the oil recovery technology based on fire flooding in our country.It's one of the most efficient heavy oil recovery technologies,the pyrolysis of heavy oil in the process involves the complicated situation of the co-existence of heat,gas and oil.It's very important to master the condition of heavy oil pyrolysis.The process of heavy oil pyrolysis is affected by temperature and pyrolysis atmosphere together.In this paper,Liaohe Q block heavy oil is taken as the object of study,and the pyrolysis characteristics and product properties of heavy oil are explored.?1?The basic physical properties of heavy oil and oil sand have been analyzed.The results showed that Q block heavy oil is extra heavy oil with 97.30%C and H elements and only 4.12%asphaltenes.The oil content of sand is more than 6.8%.The pyrolysis process of oil sand have been studied by thermogravimetric analyzer?TGA?.The results of TGA showed that pyrolysis process of oil sand A and B can be divided into 3stages:weak bond breaking volatilization of light components,recombinant dissociation into oil and coke and carbonization of residual organic matter.The activation energy of pyrolysis?E?increased with the increase temperature,and reached the maximum in 3rd stage were 262.670 and 194.733kJ mol^-1.?2?The pyrolysis process of heavy oil in N₂,CO₂ and air atmospheres,was studied by TGA and fixed-bed reactor.The results of TGA showed that the pyrolysis process of heavy oil can be divided into 3 stages:light components and water volatile,weak chemical bond breakage and recombinant dissociation into oil and coke.The average mass loss rate of heavy oil pyrolysis under N₂ and CO₂ is similar.The results of pyrolysis experiments in fixed-bed reactor showed that the yield of liquid products increased with the increase of temperature,the pyrolysis gas and the residue yield decreased,and the maximum liquid product yield appeared in 61.53%of the CO₂ atmosphere at 650?.The pyrolysis experiments in fixed-bed with different flow rate of experimental atmosphere showed that the yields of liquid products and pyrolysis gas increased with the decreasing of experimental atmosphere flow rate,while the residue yields decreased.The maximum liquid product yield appeared in 66.93%of the N₂ at 30mL min^-1.E increased with the temperature in 3rd stage,and reached the maximum were 142.871 and 148.824kJ mol^-1.?3?TGA and Fourier transform infrared spectroscopy?FTIR?were used to analyze the oxidation and chemical composition of the liquid products of heavy oil pyrolysis respectively.The results of TGA showed that the TG curve was obviously shifted to the high temperature region and the mass loss was weakened with the pyrolysis temperature increasing.Compared with N₂,the oxidation mass loss of liquid products obtained by pyrolysis of CO₂ atmosphere is faster.The infrared spectras of the liquid products and the heavy oil at different temperatures showed that the contents of the methyl groups increased and the contents of the methylene groups decreased with the increase of pyrolysis temperature.?4?The analysis of pyrolysis gas by gas chromatograph showed that the oxygen atmosphere is not conducive to the production of pyrolytic liquid products.Considering the pyrolysis temperature and atmosphere flow of the two most important factors for improving and stabilizing fire flooding heavy oil recovery should be maintain the appropriate high temperature,using the flue gas?such as N₂ and CO₂?and heavy oil in full contact.