硅藻土作用下CO2水合物生成特性OA

Diatom with a purity above 99.5%was selected to prepare a suspension solution,and ex-periments were conducted to observe the kinetics,morphology,and sedimentation behavior of hydrate formation to investigate their effects on CO2 hydrate formation.Experimental results indicate that the electrical sensitivity index of diatom is 0.184,classifying it as low sensitivity.However,the unique hollow and porous microstructure of diatom provides additional nucleation sites,thereby promoting the later-stage formation of hydrates.When the pressure is below 3.8 MPa,the promoting effect of diatoms on hydrate formation becomes increasingly apparent.The complete hydrate formation time in the diatom suspension is 10%shorter than in the deionized water system,with a temperature increase of 0.8℃.Due to the sedimentation behavior of diatomaceous earth,mass transfer is difficult,resul-ting in a hydrate conversion rate of only 4.91%.The area occupied by hydrate in the observation win-dow is 59.04%,and the ratio of the amount of substance consumed by the gas in the diatomaceous earth system to that consumed by the gas in the deionized water system is 48.39%.Furthermore,ob-servations of the sedimentation behavior of diatoms show that hydrate films preferentially form at the gas-liquid interface.Due to the traction effect of surface tension,the gas-liquid contact area increases,further promoting hydrate formation.These experimental results elucidate the mechanism by which diatoms influence the formation of CO2 hydrates,providing insights and references for carbon seques-tration in geological conditions.