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As we know, there are three structures-sⅠ, sⅡ, and sH, with hydrocarbonate gas hydrate. Because of those special structures characteristics and potentail large fossil energy resource, gas hydrate play an important role in natural carbonate cycle system. In this paper, CH_4, CO_2, C_3H_8, and CH_4+CO_2 system have been experimental performed in order to model hydrate formation and discomposition and to obtain hydrate stability conditions of tempreature and pressure. The results from laboratory using Raman spectra show that Raman spectrascopy is a effective tool to identify hydrate structure. Raman spectra of clathrate hydrate guest molecules are presented for two structure (sⅠ and sⅡ) in the following systems: CH_4, CO_2, C_3H_8. Relatively occupancy of CH_4 in the large and small cavities of sⅠ were determined by deconvoluting the v_1 symmetric bands, resulting in hydration numbers of 6.04±0.03. The freqyuency of the v_1 bands for CH_4 in structures Ⅰ and Ⅱ differ statistically. The large cavities were measured to be almost fully occupied by CH_4 and CO_2, whereas only a small fraction of the small cavities are occupied by CH_4. No CO_2 was found in the small cavities.
As we know, there are three structures-sI, sII, and sH, with hydrocarbonate gas hydrate. Because of these special structures characteristics and potentail large fossil energy resource, gas hydrate play an important role in natural carbonate cycle system. In this paper, CH_4, CO_2, C_3H_8, and CH_4 + CO_2 system have been experiment performed in order to model hydrate formation and discomposition and to obtain hydrate stability conditions of tempreature and pressure. The results from laboratory using Raman spectra show that Raman spectrascopy is a effective tool to Identify hydrate structure. Raman spectra of clathrate hydrate guest molecules are presented for two structures (sⅠand sⅡ) in the following systems: CH_4, CO_2, C_3H_8. Relatively occupancy of CH_4 in the large and small cavities of sⅠ were determined by deconvoluting the v_1 symmetric bands, resulting in hydration numbers of 6.04 ± 0.03. The freqyuency of the v_1 bands for CH_4 in structures I and Ⅱ differ statis tically. The large cavities were measured to be almost fully occupied by CH_4 and CO_2, and only only a small fraction of the small cavities are occupied by CH_4. No CO_2 was found in the small cavities.