查看更多>>摘要：The oil shale of the Uvdug Khooloin Gashuun deposit, located in Mongolia, has a relatively high content of volatiles (28.40%), but its caloric value is low (1780.0 kl/kg). Furthermore, it was found to have a relatively high content of organic carbons and a low content of heteroatomic compounds containing elements N, S, O, halogens (X), etc. The ash of oil shale, dominated by aluminosilicates (SiO2 + Al2O3/CaO + MgO = 10), is acidic and contains more than 40 heavy and toxic elements. The pyrolysis carried out under nitrogen at 500-550 degrees C produced shale oil (11.21%), pyrogenetic water (11.09%), gases including losses (8.10%), and semi-coke (69.50%). By gas chromatographic-mass spectrometric (GC MS)analyses, 279 (mainly C-7-C-17 n-alkanes and n-alkenes, 36.69%) and 323 (mainly C-12-C-19 n-alkanes and n-alkenes, 43.08%) individual organic compounds were identified in both light and middle shale oil distillates, respectively. Also, the neutral sub-fraction (93.1%) of the middle distillate is composed of a large amount of C-10-C-24 aliphatic hydrocarbons (70.1%) and a negligible amount of acidic and basic organic compounds (6.9%). The study results suggest that the Uvdug Khooloin Gashuun oil shale could be used as a raw material for liquid fuels.
查看更多>>摘要：In this paper, the catalytic pyrolysis of Jimsar oil shale was studied using CoCl2 center dot 6H(2)O as a catalyst. The thermogravimetric analysis (TGA) was carried out on oil shale samples with the catalyst added. The kinetic analysis of the pyrolysis reaction of each sample was performed using the main curve method and several model-free methods. The results showed that CoCl2 center dot 6H(2)O could not only reduce the average activation energy of oil shale pyrolysis from 216 kJ/mol to 163 kJ/mol, but also decrease the pyrolysis temperature by about 100 degrees C.
查看更多>>摘要：A three-dimensional (3D) molecular model of Dachengzi oil shale kerogen was constructed using quantitative C-13 direct polarization/magic angle spinning solid-state nuclear magnetic resonance (DP/MAS SSNMR) data and accurate quantum chemistry methods. The heteroatom-containing functional groups were carefully identified using X-ray photoelectron spectroscopy (XPS) and pyrolysis experimental data. A large portion of C487H778O43N8S5 was selected for the model to introduce more types of functional groups and make the model representative. The carbon unit fractions, structural parameters and atomic ratios of the model well matched with the experimental data. The equilibrium structure was obtained by geometry optimization using the density functional theory (DFT) method at the B3LYP/STO-3G level of theory and validated by frequency calculations at the same level. The final geometry is an incompact structure containing a large number of branches, which well reflects the cross-linked molecular structure of the kerogen. The simulated C-13 NMR spectrum was generated using quantum chemical calculations at the B3LYP/6-3IG(d) level. The simulated spectrum is in good agreement with the experimental spectrum, indicating the validity and reliability of the model.
查看更多>>摘要：A method was developed to predict the collapse of underground rooms in a previously mined area. This methodology is necessary to assess the condition of the excavated areas in the case of an additional load of buildings and supporting pillars weakening. As an example, the ground stability of the Estonia mine under the waste dump has been calculated.
NSTL
Estonian Acad Publishers