scholarly journals Macro and Meso Characteristics of In-Situ Oil Shale Pyrolysis Using Superheated Steam

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2297 ◽  
Author(s):  
Lei Wang ◽  
Dong Yang ◽  
Xiang Li ◽  
Jing Zhao ◽  
Guoying Wang ◽  
...  

The efficiency of oil shale pyrolysis is directly related to the feasibility of in-situ mining technology. Taiyuan University of Technology (China) proposed the technology of in-situ convective heating of oil shale, which uses superheated steam as the heat carrier to heat the oil shale’s ore-body and transport the pyrolysis products. Based on the simulated experiments of in-situ oil shale pyrolysis using superheated steam, the changes in fracture characteristics, pyrolysis characteristics and mesoscopic characteristics of the oil shale during the pyrolysis have been systematically studied in this work. The Xinjiang oil shale’s pyrolysis temperature ranged within 400–510 °C. When the temperature is 447 °C, the rate of pyrolysis of kerogen is the fastest. During the pyrolysis process, the pressure of superheated steam changes within the range of 0.1–11.1 MPa. With the continuous thermal decomposition, the horizontal stress difference shows a tendency to first increase and then, decrease. The rate of weight loss of oil shale residue at various locations after the pyrolysis is found to be within the range of 0.17–2.31%, which is much lower than the original value of 10.8%, indicating that the pyrolysis is more adequate. Finally, the number of microcracks (<50 µm) in the oil shale after pyrolysis is found to be lie within the range of 25–56 and the average length lies within the range of 53.9636–62.3816 µm. The connectivity of the internal pore groups is satisfactory, while the seepage channel is found to be smooth. These results fully reflect the high efficiency and feasibility of in-situ oil shale pyrolysis using superheated steam.

Oil Shale ◽  
2018 ◽  
Vol 35 (3) ◽  
pp. 230 ◽  
Author(s):  
L WANG ◽  
D YANG ◽  
J ZHAO ◽  
Y ZHAO ◽  
Z KANG
Keyword(s):  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuai Zhao ◽  
Xiaoshu Lü ◽  
Youhong Sun ◽  
Jiandong Huang

AbstractTopochemical heat in-situ pyrolysis of oil shale is achieved by injecting high temperature nitrogen to promote oil shale pyrolysis and release heat, and then injecting air to trigger oil shale combustion in the early stage of oil shale pyrolysis, and then by injecting normal temperature air continuously to promote local oxidation of oil shale in the later stage. In order to verify the oil and gas recovery by topochemical heat method, Jilin University has chosen Fuyu City, Jilin Province, to carry out pilot project of oil shale in-situ pyrolysis by topochemical heat method. Besides, in order to infer the spontaneity, feasibility and difficulty of continuous pyrolysis of oil shale based on topochemical heat, this paper, the mechanism of solid-state pyrolysis and the thermodynamic analysis of transition state of oil shale in Fuyu area are discussed. Because the second stage of oil shale pyrolysis is the main stage of oil production. Therefore, the characteristics of Gibbs free energy, free enthalpy and free entropy of transition state in the main oil production stage of oil shale pyrolysis are obtained by calculation. The results show that in situ pyrolysis of oil shale topochemical heat can be carried out spontaneously and continuously, and the release characteristics of volatiles during pyrolysis of oil shale are described.


2019 ◽  
Vol 235 ◽  
pp. 1468-1475 ◽  
Author(s):  
Tarik Saif ◽  
Qingyang Lin ◽  
Ying Gao ◽  
Yousef Al-Khulaifi ◽  
Federica Marone ◽  
...  
Keyword(s):  
X Ray ◽  

2020 ◽  
Author(s):  
Zhao Shuai ◽  
LÜ Xiaoshu ◽  
Sun Youhong ◽  
Huang Jiandong

Abstract Topochemical heat in-situ pyrolysis of oil shale is achieved by injecting high temperature nitrogen to promote oil shale pyrolysis and release heat, and then injecting air to trigger oil shale combustion in the early stage of oil shale pyrolysis, and then by injecting normal temperature air continuously to promote local oxidation of oil shale in the later stage. In order to verify the oil and gas recovery by topochemical heat method, Jilin University has chosen Fuyu City, Jilin Province, to carry out pilot project of oil shale in-situ pyrolysis by topochemical heat method. Besides, in order to infer the spontaneity, feasibility and difficulty of continuous pyrolysis of oil shale based on topochemical heat, this paper, the mechanism of solid-state pyrolysis and the thermodynamic analysis of transition state of oil shale in Fuyu area are discussed. Because the second stage of oil shale pyrolysis is the main stage of oil production. Therefore, the characteristics of Gibbs free energy, free enthalpy and free entropy of transition state in the main oil production stage of oil shale pyrolysis are obtained by calculation. The results show that in situ pyrolysis of oil shale topochemical heat can be carried out spontaneously and continuously, and the release characteristics of volatiles during pyrolysis of oil shale are described.


2014 ◽  
Vol 521 ◽  
pp. 666-670
Author(s):  
Yun Xia Bian ◽  
De Min He ◽  
Guo Zhu Kuang ◽  
Qiu Min Zhang

Proximate analysis, ultimate analysis and CO2of carbonate were determinated for the aboveground oil shale in Daqing exploratory area. The experiments of pyrolysis of Daqing oil shale were carried out in a fixed-bed reactor in order to study the influence of the pyrolysis temperature and the constant temperature time on oil shale pyrolysis characteristics. The results show that the effect of the pyrolysis is optimal under the conditions of 500°C and the constant temperature time for 20 min, with the yield of shale oil for 28.78% (the yield based on kerogen, similarly hereinafter). The mechanism of the oil shale pyrolysis was discussed. The pyrolysis reaction kinetics of oil shale was studied combining the experimental results of fixed-bed pyrolysis. The reaction activation energy is 28.92 kJ/mol during generating the shale oil process, while the reaction activation energy is 11.21 kJ/mol during generating char process. The yield curve of shale oil changing with the temperature was fitted to compare with the measured value with the constant temperature time for 20 min according to the pyrolysis kinetic parameters.


2018 ◽  
Author(s):  
Devon Jakob ◽  
Le Wang ◽  
Haomin Wang ◽  
Xiaoji Xu

<p>In situ measurements of the chemical compositions and mechanical properties of kerogen help understand the formation, transformation, and utilization of organic matter in the oil shale at the nanoscale. However, the optical diffraction limit prevents attainment of nanoscale resolution using conventional spectroscopy and microscopy. Here, we utilize peak force infrared (PFIR) microscopy for multimodal characterization of kerogen in oil shale. The PFIR provides correlative infrared imaging, mechanical mapping, and broadband infrared spectroscopy capability with 6 nm spatial resolution. We observed nanoscale heterogeneity in the chemical composition, aromaticity, and maturity of the kerogens from oil shales from Eagle Ford shale play in Texas. The kerogen aromaticity positively correlates with the local mechanical moduli of the surrounding inorganic matrix, manifesting the Le Chatelier’s principle. In situ spectro-mechanical characterization of oil shale will yield valuable insight for geochemical and geomechanical modeling on the origin and transformation of kerogen in the oil shale.</p>


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