In this paper, the promoting effect of green biological surfactant octylbetaDglucopyranoside on ethylene hydrate formation was experimentally investigated, in futher, the mechanism of promoting was also briefly explored. First, the effect of octylbetaDglucopyranoside on ethylene hydrate formation condition was researched. Then, the effect of octylbetaDglucopyranoside on ethylene hydrate formation rate and storage capacity was also tested. At last, the solubility of ethylene under the condition of phase equilibrium through Hysys was studied. The results show that compare with deionized water system, OctylbetaDglucopyranoside has little effect on ethylene hydrate formation in thermodynamics. While in the kinetics, it can dramaticlly decrease the induction time of ethylene hydrate formation and increase the rate of ethylene hydrate formation more than three times. In addition, the storage capacity can be increased by 50%, under the condition of 283.15 K and 2.20 MPa with storage capacity of 164.71, which is close to the theory storage volume. Under the condition of phase equilibrium, the dissolved value of ethylene in octylbetaDglucopyranoside solution is significantly higher than that in deionized water system, but is far less than the consumption of hydration.

Process simulation software Aspen HYSYS was used to establish British DAVY seriesparallel methanol synthesis upon steady state process in this study. A concept of equilibrium temperature interval was used to show the distance to equilibrium state in the model of equilibrium reactor. According to the contrast results of influence of exhausted gas positions on inlet gas and outlet gas mole fraction of methanol syntheses reactors, mass flow of crude methanol, mass fraction of crude methanol and recycle gas mass flow, different exhausted gas positions were proposed. Mass flow of recycle gas could be reduced at a lower value with this new exhausted gas position, which could widen the operation flexibility of methanol synthesis process. It could play a direct role in the actual production as well as design of following new process.

In order to simulate the effect of leakage of natural gases with high contents of CO ₂ and N ₂ on the methane hydrates reservoir overlying, the replacement experiments of CH ₄ hydrates by using two groups of gas mixtures were observed with a selfdesigned device at 277.15 K, initial pressure 6.37 MPa and at 275.15 K, initial pressure 4.30 MPa respectively. The quartz sand and 3.5% NaCl aqueous solution were mixed to simulate seafloor and two groups of gas mixtures, one has high contents of N ₂ and another has high contents of CO ₂, were chosen from northern South China Sea. Experimental data show that the variation of CO ₂ is the most and the variation of N ₂ is much less. It indicate that CO ₂ plays a leading role. The replacement efficiency of two groups of gas mixtures at different experimental conditions are 8.64% and 20.71% at 140 h of experiment. Based on the experimental results, a simple replacement mechanism of CH ₄ hydrate dissociated with CO ₂ in porous medium system was proposed.