Experiment study on CBM hydrates formation in tubular reactor stuff with porous medium

As a traditional purification technology (low temperature liquefaction,pressure swing absorption,membrane separation,etc. ) is not applicable to low concentration coal bed methane ( CBM),a new technology is put forward, which achieves the enrichment of CH4 with low concentration CBM in a hydrates formation way. However,to implement such technology,there are two problems in the process of CBM hydrates formation,such as low hydrates formation rate and low gas storage density,which are required to be solved. The tubular reactor test results in Japan and the research achievements obtained from the current theoretical research and experimental study including the optimum concentra- tion ratio promoted by THF and SDS based on the hydrates formation phase equilibrium condition,gas density and hy- drates formation rate and the promotion of porous medium to hydrates formation are used for reference in this study. The change of hydrates formation rate and industrial implementation under the optimum promotion system of molar fraction of 17% THF+mass concentration of 300×10-6 SDS theory are investigated by taking the tubular reactor filled with 5×10-10 m zeolite as the CBM hydrates formation interface. The results show that with the increase of the forma- tion pressure,the rate of the whole pipeline reaction rate increases and the peak moves forward along the pipeline; with the increase of the hydrate driving force,the gas storage efficiency of hydrate is improved,and the effect of over- voltage driving force on hydrate gas storage is stronger than that of under-cooling driving force; in the condition of 284 K / 1. 5 MPa,after primary formation,the second formation is generated by porous medium,when the same gas storage capacity is achieved,ge,the secondary formation time is only 10% of the first formation time; in the condition of 284 K / 1. 8 MPa,with the increase of the formation time,the gas consumption per formation unit reaches 67. 25 mL /mL,and the formation rate and gas density of the hydrates can be improved greatly by using the shortening effect of secondary formationtime.