| Ranking second in the world, our country enjoys rich coal resources. Among the fossil energy sources, coal is mainly direct used as fuel to provide heat and electricity, the proportion of electricity generation accounted for 78% of China's total electricity consumption. However, due to their chemical composition of coal, fire coal also generates massive smoke and harmful ingredients, such as CO2, NO2 and SO2, which causes serious environmental pollution, including fog haze, greenhouse effect, and acid rain. Therefore, we must vigorously develop clean coal technology. Clean Coal Technology, based on macromolecular structure and composition of coal, is a technology which realizes cascade processing and low-carbon utilizing for coal to achieve highly efficient and selective conversion of coal in terms of fine chemicals and clean fuels. Thus, it makes a kind of new model of coal chemical development, presenting "green economy, coordinated, sustainable."The research of coal structure has been a core part of the science of coal fields, which plays a significant role in clean coal fields. According to characterization of Hulunbeier coal liquefaction sample, this paper constructs coal macromolecular structure modeling methods; Further, through the coal autoclave test, this paper discusses the relationship between the direct liquefaction results and composition of coal structure; then examines the liquefaction reaction performance under different temperature and different time; besides studies the oil performance by groups separation, tighter with GC-MS method. According to the above research, the author gets the following conclusions:1. According to the element analysis, the coal sample is mainly composed of element of C, H, O. Combined industrial analysis of coal samples, atomic ratio of H/C, O/C, N/C can be obtained 60.50%,,20.8%and 1.2% respectively.2. Coal structure is mainly di-substituted benzene ring according to FT-IR analysis of coal sample; Nitrogen atom exists in the form of pyridine and pyrrole and oxygen in the structural model mainly exists in the form of hydroxyl or carboxyl through XPS analysis; XRD analysis indicate microcrystalline structure parameters of coal sample, in which has 8 or 9 layers network, and the diameter between layers is 3.67nm.; The 13C chemical shift of this model is obtained using 13C-CP/MAS NMR, indicating that and the structure is mainly consists of aromatic carbon types and the aromaticity of Hulunbeier brown coal is 0.6615.3. Aromatic structure unit information can be obtained according to the XBP. Coal sample is given priority to benzene and naphthalene. Fat structure mainly is consists of short chain alkyl, a ethylene, and cycloalkane group; In ACD/CNMR software to build the structure model of coal sample, use ACD/CNMR Predictor software to forecast the macromolecular structure, and find the calculated 13C-NMR spectra of better and experimental spectra of coal structure model; finally get the formula of the coal sample C174H121O36N2.4. Under different liquefaction condition, coal conversion, oil yield, hydrogen consumption, gas yield rate rise with temperature (time) increasing, and the growth rate present a "S" curve; however, asphaltene yield first increases then decreases with temperature (time) increasing. Combining effect of different conditions of temperature and time, the best liquefaction condition of coal sample is 455? and 60min; gas composition mainly is distributed in the form of C1-C4 alkanes and carbon oxides, which the yield of CH4 is the most higher.5. Liquefaction oil based on column chromatography and GC-MS analysis, exploring coal liquefaction oil group composition, liquefaction oil is mainly is consists of aromatic substances and saturated hydrocarbon components. Aromatic component mainly is in the form of naphthalene and tetralin and their derivatives and saturated hydrocarbons mainly are consist of C10-C20 straight chain. |
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