Static Experiment Study On The Hydrate Storage Of CO₂ In Quartzite

In recent years, the greenhouse effect and the climate change have influence on the production and the life of human. The greenhouse gas emissions, especially carbon dioxide, have become the focus of attention.Hydrate storing carbon is one of the methods solution the problem. Gaseous carbon dioxide and liquid water could format solid hydrate at a certain temperature, pressure, thus the carbon dioxide emission reduced with the carbon fixation. And the greenhouse effect will decrease. This technique has low energy-consuming and the gas storage time is very long. Currently hydrate storing carbon is still in study with some problems. One of these is the effect of porous media on carbon dioxide gas storage capacity.The experimental study in porous quartzite with nominal diameters of 26.7nm and 13.8nm are reported in this work. It was experimented in a 1.8L stainless steel in constant volume system. The initial state of the system is 25℃,3.6 MPa. Reduce the temperature to 0.5℃. After the hydrate completely formatted,rise the temperature to 25℃. The hydrate formation procedure was recorded by data collector. The mole of gaseous carbon dioxide could be calculated by PR state equation in chemical thermodynamics,and the solution of carbon dioxide in water could be calculated by the research achievements of Duan et al.. And the gas storage capacity could be calculated by the above results. The gas storage of carbon dioxide hydrate in quartz with nominal diameters of 26.7nm is 118.8m3 in 1m3 quartz. The instantaneous formation rate of carbon dioxide in this experimental is 0.000457mol/min.The instantaneous dissociation rate of carbon dioxide in this experimental is 0.1071mol/min.The average formation rate of carbon dioxide in this experimental is 0.001703mol/min.The average dissociation rate of carbon dioxide in this experimental is 0.01195mol/min. The gas storage of carbon dioxide hydrate in quartz with nominal diameters of 13.8nm is 64.4m3 in 1m3 quartz. The instantaneous formation rate of carbon dioxide in this experimental is 0.0422mol/min.The instantaneous dissociation rate of carbon dioxide in this experimental is 0.1091mol/min.The average formation rate of carbon dioxide in this experimental is 0.001803mol/min.The average dissociation rate of carbon dioxide in this experimental is 0.01039mol/min. It is drew a comparison between the storage capacity of 26.7nm group and he storage capacity of 13.8nm group.In water saturated porous media, it is determined that pore size has influence on the storage capacity of carbon dioxide of the carbon dioxide hydrate. In porous quartzite with nominal diameters of 13.8nm, it could be storage 118.8 m3 carbon dioxide in 1 m3 quartz. This work provides a theoretical basis for carbon dioxide storage in seafloor.