Effect of liquid carbon dioxide phase change fracturing technology on gas drainage

2017 ◽  
Vol 10 (14) ◽  
Author(s):  
Hai-dong Chen ◽  
Zhao-feng Wang ◽  
Ling-ling Qi ◽  
Feng-hua An
Keyword(s):  
Carbon Dioxide ◽  
Phase Change ◽  
Liquid Carbon ◽  
Gas Drainage ◽  
Liquid Carbon Dioxide

Permeability enhancement and porosity change of coal by liquid carbon dioxide phase change fracturing

2021 ◽  
Vol 287 ◽  
pp. 106106
Author(s):  
Xianfeng Liu ◽  
Baisheng Nie ◽  
Kunyong Guo ◽  
Chengpeng Zhang ◽  
Zepeng Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Phase Change ◽  
Liquid Carbon ◽  
Liquid Carbon Dioxide ◽  
Porosity Change ◽  
Permeability Enhancement

scholarly journals Increasing Permeability of Coal Seam and Improving Gas Drainage Using a Liquid Carbon Dioxide Phase Transition Explosive Technology

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Wenrui He ◽  
Fulian He ◽  
Kun Zhang ◽  
Yongqiang Zhao ◽  
Hengzhong Zhu
Keyword(s):  
Phase Transition ◽  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Blast Hole ◽  
Liquid Carbon ◽  
Gas Drainage ◽  
Liquid Carbon Dioxide ◽  
Drainage Hole ◽  
Drainage Effect ◽  
Coal Damage

The low permeability of coal seams makes gas drainage difficult in lots of coal mines. This study presents a low-temperature, safe, and efficient liquid carbon dioxide phase transition explosive technology (LCDPTET) to increase the permeability of coal, thereby improving the efficiency of gas drainage and eliminating the dangers of coal and gas outburst. Meanwhile, an integrated approach for experimental determination, numerical simulation, and field testing was applied to study the damage ranges of coal and to determine a reasonable spacing between the gas drainage hole and blast hole. A numerical simulation model of liquid carbon dioxide phase transition explosion (LCDPTE) was built, and the damage index M was introduced to analyze the degree and range of coal damage after explosion at different spacings between the blast hole and the gas drainage hole. Furthermore, another aim was the assessment of the permeability changes and comparison of the gas drainage effects of different borehole spacings. The results showed that as the borehole spacing became smaller, the degree of coal damage around the gas drainage hole increased, and the gas drainage effect improved. However, to avoid the collapse of the gas drainage hole, the gas drainage holes should not be located in the crushing zone caused by LCDPTE. Based on the numerical analysis conducted to guide the borehole arrangement of the field test, the latter was carried out to study the increasing ranges of permeability of coal and the drainage effect after explosion. The results indicated that LCDPTET could greatly improve the permeability of the coal seam and gas drainage efficiency. In addition, this new technology could not only improve the safety and efficiency of mine production but could also turn carbon dioxide into an effective energy source worthy of popularization and application.

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

2021 ◽  
Author(s):  
Yun Lei
Keyword(s):  
Carbon Dioxide ◽  
Phase Change ◽  
Low Permeability ◽  
Gas Explosion ◽  
Coal Seams ◽  
Liquid Carbon ◽  
Liquid Carbon Dioxide ◽  
Coal Roadway ◽  
Geological Conditions ◽  
High Efficient

Abstract 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.

Ultrasonic velocity in liquid carbon dioxide

Physica ◽  
1973 ◽  
Vol 63 (1) ◽  
pp. 154-162 ◽  
Author(s):  
W. Pecceu ◽  
W. Van Dael
Keyword(s):  
Carbon Dioxide ◽  
Ultrasonic Velocity ◽  
Liquid Carbon ◽  
Liquid Carbon Dioxide

scholarly journals Submarine venting of liquid carbon dioxide on a Mariana Arc volcano

2006 ◽  
Vol 7 (8) ◽  
pp. n/a-n/a ◽  
Author(s):  
John Lupton ◽  
David Butterfield ◽  
Marvin Lilley ◽  
Leigh Evans ◽  
Ko-ichi Nakamura ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Liquid Carbon ◽  
Liquid Carbon Dioxide ◽  
Mariana Arc ◽  
Arc Volcano

Complex Formation of Semifluorinated γ-Cyclodextrin and Surfactants in Liquid Carbon Dioxide

2006 ◽  
Vol 45 (10) ◽  
pp. 3434-3437 ◽  
Author(s):  
Ha Soo Hwang ◽  
Min Young Lee ◽  
Yeon Tae Jeong ◽  
Seong-Soo Hong ◽  
Yeong-Soon Gal ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Complex Formation ◽  
Liquid Carbon ◽  
Liquid Carbon Dioxide

scholarly journals Liquid Carbon Dioxide Use in the Extraction of Extra Virgin Olive Oil From Olive Paste

2014 ◽  
Vol 3 (4) ◽  
pp. 119 ◽  
Author(s):  
Raffaele Romano ◽  
Nadia Manzo ◽  
Immacolata Montefusco ◽  
Annalisa Romano ◽  
Antonello Santini
Keyword(s):  
Carbon Dioxide ◽  
Fatty Acids ◽  
Olive Oil ◽  
Virgin Olive Oil ◽  
Extra Virgin Olive Oil ◽  
Liquid Carbon ◽  
Liquid Carbon Dioxide ◽  
A Value ◽  
Olive Mill Waste Water

<p>In this study the use of liquid carbon dioxide, CO<sub>2</sub>, for extraction of oil from olive paste (<em>Peranzana cultivar</em>)<strong> </strong>were examined and extracted oil was compared with oils obtained by centrifugation, pressure and use of chemical solvent.</p> <p>It is well known that the use of CO<sub>2</sub> has many advantages: miscibility with a wide range of molecules, food safety, non-flammability, absence of residues in the extract, possibility of total solvent recovery and no production of olive mill waste water that are highly polluting for the environment and require expansive disposal.</p> <p>Samples were subjected to the following analyses: determination of Free Fatty Acids (FFA), Peroxides Value (PV), Spectrophotometric Indices, Fatty Acids Composition (FA), determination of biophenols content and determination of Volatile Organic Compounds (VOCs). All samples showed FFA, PV and ?K values within the limits established by law for extra-virgin olive oil. The use of CO<sub>2</sub> did not catalyze hydrolysis, oxidation and condensation of double bonds. Centrifuged oils and oils extracted with carbon dioxide presented the lowest PV and FFA values. Extraction with liquid carbon dioxide contributed to an increasing of phenolic content with a value of 270.5 mg/kg, a value twice that of the oils extracted with centrifugation (135.3 mg/kg) or pressure methods (173.2 mg/kg). Oil extracted with liquid carbon dioxide showed the greatest amount of t-2-octenal and t-2-heptenal, giving herbaceous and pungent notes. Moreover the presence of aromatic compounds such as limonene, generally absent in olive oils, was only detected in the sample extracted with liquid carbon dioxide.</p>

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