Search

In order to find an appropriate thermodynamic model of rectisol process, the SRKH model of low-temperature methanol absorption was established and parameter regression was used to abtain all binary interaction parameters of the NRTL equation for rectisol system. The correctness of the arguments was verified by the vapor-liquid equilibrium calculations. An industrial absorber in China was simulated and the CO2, and H2S concentration distribution in the absorber was obtained. The results show that the SRKH model is suitable for rectisol system. The effects of operating conditions on rectisol system were investigated and the concentration variations of CO2 and H2S in purified gas caused by the changes of operating conditions were obtained. The acidic gas concentration in purified gas decreases along with the increase of pure methanol flow or/and the decrease of methanol temperature and the concentration of H2S can be reduced to less than 0.1x106 quickly. Therefore, qualified gas with different CO2 concentrations can be produced by changing the flow of pure methanol or methanol temperature. The effect of crude gas flow on pure methanol flow was also investigated when the concentration requirements of acidic gases in purufied gas of coal gasification methanol synthesis process were meet; and results show that the flow of pure methanol increased with the augment of crude gas flow and the extent of growth decreases gradually, which indicates that it is beneficial to enlarge the scale so as to reduce operating cost in advanced coal chemical industry. [ABSTRACT FROM AUTHOR]

Traditional emulsion explosives sensitized by NaN02 has a low explosion power, and it is sensitive to external pressure which causes its explosion power decreased. In order to improve detonation performances of emulsion explosives, the hydrogen composite emulsion explosive was produced. The hydrogen composite emulsion was sensitized by MgH2, and MgH2 powders participated in the detonation process, so the explosion power increased; when the emulsion suffered from the external pressure, the unreacted MgH2 powders would be decomposed to reduce the damage of sensitization bubbles. Through shockwave producing device and underwater explosion experiments, the effects of chemical sensitizers MgH2 and NaN02 on emulsion explosives property were studied. Compared with emulsion explosives sensitized by NaN02, emulsion explosive sensitized by MgH2 presents much smaller desensitized ratio and stronger explosion power. Finally, with the help of scanning electron microscope, the microstructures of emulsion explosives were studied, pressure desensitization mechanisms of two emulsion explosives sensitized by chemical bubbles were discussed. [ABSTRACT FROM AUTHOR]

High temperature conventional triaxial compression test of shale were carried out by using the MTS815 servo-controlled testing machine, based on the results of the tests, the relationships between confining pressure and the characteristic of shale stress-strain curve, peak strength, elastic modulus, Poisson's ratio, peak strain were investigated,and the general regulation is obvious. According to the characteristics of volumetric strain,the stress-strain curves were classified into three types. They are dilatation type,compression-dilatation type,compression type,and the confining pressure has conspicuous dilatation effect on shale. At the same temperature, when confining pressure rises from 5 MPa to 25 MPa, shale peak strength (σ1 - σ3) is comparatively lower, indicating stronger plastic deformation', and peak strength and elastic modulus increase with uprising confining pressure. When confining pressure is lower than 15 MPa, shale Poisson' s ratio increases with increasing confining pressure while peak axial strain and peak circle strain decreases with increasing confining pressure. When confining pressure is higher than 15 MPa, shale Poisson's ratio decreases slightly with the increasing confining pressure, while peak axial strain and peak circle strain increase slightly with the increasing confining pressure. [ABSTRACT FROM AUTHOR]

In order to study the influence of coal dust on premixed methane-air flame propagation in tube,the typical coal dust was well-distributed at the bottom of square plexiglass tube with its section 100 mm x 100 mm and 1.5 meters long. The high speed video camera/photoelectric sensors, subtle thermocouples and pressure sensors were adopted to obtain the premixed methane-air flame parameters including flame propagating velocity, flame transient temperature and deflagration pressure along the tube, respectively. And the mechanisms of the coal dust influencing flame propagation were preliminarily analyzed. The experimental results show that coal dust can accelerate the methane-air flame propagation in tube, and the flame propagating velocity is increased, but the combustion duration is also increased;the half-peak width of the temperature is broadened under the condition of coal dust in tube, and the transient temperature values of methane-air premixed flame at testing points obviously presents the wave of "twin peaks structure", which suggests that the reactive coal dust and the methane forms the methane/coal-dust composite flame;there is no obvious difference for the combustion peak-pressure with or without coal dust, but the pressure pulse width is broadened in coal dust condition. [ABSTRACT FROM AUTHOR]