This study analyzed the partial effect of carbon dioxide hydrate in reaction kettle experiments.The particle and bubble characteristics of the crystal nucleus during carbon dioxide hydrate decomposition were observed ...This study analyzed the partial effect of carbon dioxide hydrate in reaction kettle experiments.The particle and bubble characteristics of the crystal nucleus during carbon dioxide hydrate decomposition were observed under the microscope.The results showed that in the temperature range of 0.5℃–3.5℃,the pressure range of 3 MPa–5.5 MPa,phase characteristics in the reaction kettle changed in a complex fashion during carbon dioxide hydrate formation.During hydrate decomposition,numerous carbon dioxide bubbles were produced,mainly by precipitation at high temperatures or in the hydrate cage structure.The hydrate crystal nucleus initially exhibited fluidity in the reaction.However,as the reaction progressed,the hydrate crystal nucleus migrated upward under the influence of gravity and carbon dioxide diffused into the aqueous phase.Next,the hydrate was formed and accumulated,finally forming a solid carbon dioxide hydrate layer.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.51574089)Heilongjiang Provincial Department of Education(TSTAU-R2018018)the Innovative scientific research project for Postgraduates of Northeast Petroleum University(YJCX2016-013NEPU).
文摘This study analyzed the partial effect of carbon dioxide hydrate in reaction kettle experiments.The particle and bubble characteristics of the crystal nucleus during carbon dioxide hydrate decomposition were observed under the microscope.The results showed that in the temperature range of 0.5℃–3.5℃,the pressure range of 3 MPa–5.5 MPa,phase characteristics in the reaction kettle changed in a complex fashion during carbon dioxide hydrate formation.During hydrate decomposition,numerous carbon dioxide bubbles were produced,mainly by precipitation at high temperatures or in the hydrate cage structure.The hydrate crystal nucleus initially exhibited fluidity in the reaction.However,as the reaction progressed,the hydrate crystal nucleus migrated upward under the influence of gravity and carbon dioxide diffused into the aqueous phase.Next,the hydrate was formed and accumulated,finally forming a solid carbon dioxide hydrate layer.