Capillary-gravitational waves and storage of liquid CO2 in the oceans

A theory of capillary-gravitational waves in the transition region between seawater and liquid carbon dioxide in deep oceans is proposed. It is shown that the thickness of the transition layer affects the properties of capillary-gravity waves. The question of the structure and stability of wave disturbances at the interface between seawater and liquefied carbon dioxide is essential for the safe storage of liquefied carbon dioxide in the ocean. This is an important issue on the current agenda in light of global warming.

Anti-Reflection Mechanism of the Coalmass under the Liquid Carbon Dioxide Phase Change Gas Explosion and the Experimental Study

The problems of high efficient coal and gas simultaneous extraction of the low-permeability and high-gas coal seams in deep mines are major problems that restrict the sustainable development of China’s coal industry. In order to solve the scientific permeability problem of the high gassy coal seams with low permeability under deep and complex geological conditions, a technology of liquid carbon dioxide phase change gas explosion for cracking and antireflection is proposed. The formation mechanism of the coalmass fracture circle resulting from liquid carbon dioxide phase change gas cracking coal is analyzed theoretically and a mathematical model within the range of fracture circle is established. Numerical simulation analysis shows that a blasting crushing zone with a radius of 1.0 m formed around the blasting hole. The radius of the secondary expansion zone caused by the explosion gas to promote coalmass formation is 2.0 m, and the limit extension length of the explosion fracture is 2.3 m. The gas phase change gas explosion is determined by the coal roadway driving face based on the gas content index and the analytical index of coal shavings to be able to reduce the pre-drainage time of coal roadway from 30 days to 15 days and 16 days. The comparison experiment also reaches a conclusion that the initial gas emission is increased by 3.7 times from the 100-meter borehole in the original coalmass after coalbed gas explosion anti-reflection. The results of the theoretical analysis are verified by underground experiments in the coal mine.