Investigation of temperature- and pressure-dependent flow characteristics of supercritical carbon dioxide- induced fractures in Harcourt granite: Application to CO2-based enhanced geothermal systems

Author(s):  
B.L. Avanthi Isaka ◽  
P.G. Ranjith
2014 ◽  
Vol 2014 (0) ◽  
pp. _S0520206--_S0520206-
Author(s):  
Hiroki TAKEUCHI ◽  
Pumaneratkul Chayadit ◽  
Haruhiko YAMASAKI ◽  
Yuhiro IWAMOTO ◽  
Hiroshi YAMAGUCHI

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4229 ◽  
Author(s):  
Yi Hu ◽  
Feng Liu ◽  
Yuqiang Hu ◽  
Yong Kang ◽  
Hao Chen ◽  
...  

Supercritical carbon dioxide (SC-CO2) fracturing is a non-aqueous fracturing technology, which has attracted considerable attention on exploiting shale gas. In this study, shale specimens and artificial sandstone specimens were used to conduct SC-CO2 fracturing and water fracturing experiments to investigate the characteristics of SC-CO2 induced fractures. An acoustic emission (AE) monitoring device was employed to monitor the AE energy release rate during the experiment. The experiment results indicate that the breakdown pressure of SC-CO2 fracturing is lower than that of water fracturing under the same conditions, and the AE energy release rate of SC-CO2 fracturing is 1–2 orders of magnitude higher than that of water fracturing. In artificial sandstone, which is homogeneous, the main fracture mainly propagates along the directions perpendicular to the minimum principal stress, no matter if using SC-CO2 or water as the fracturing fluid, but in shale with weak structural planes, the propagation direction of the fracture is controlled by the combined effect of a weak structural plane and in-situ stress.


2013 ◽  
Vol 19 (3) ◽  
pp. 389-398 ◽  
Author(s):  
Hadi Baseri ◽  
Ali Haghighi-Asl ◽  
Nader Lotfollahi

In this paper, Peng Robinson equation of state is used for thermodynamic modeling of the solubility of various solid components in the supercritical carbon dioxide. Moreover, the effects of three mixing rules of Van der Waals mixing rules, Panagiotopoulos and Reid mixing rules and modified Kwak and Mansoori mixing rules on the accuracy of calculation results were studied. Good correlations between calculated and experimental data were obtained in the wide temperature and pressure range. A comparison between used models shows that modified Kwak and Mansoori mixing rules give better correlations in comparison with the other mixing rules.


2011 ◽  
Vol 175-176 ◽  
pp. 646-650 ◽  
Author(s):  
Hong Jie Zhang ◽  
Zhi Li Zhong ◽  
Li Li Feng ◽  
Xiao Ping Quan

Polypropylene fibers were dyed with Disperse dyes Blue 2B in Supercritical Carbon Dioxide at different temperature, pressure and time. The K/S value were determined and the effect of as temperature, pressure and dyeing time on the dyeing behaviours of disperse dyes on Polypropylene fibers were discussed. It was found that with the increase of dyeing temperature and pressure, the K/S value increased gradually, and dyeing effect was best after the fiber was dyed at 120 °C, 28 MPa for 20 min.


2018 ◽  
Vol 31 (2) ◽  
pp. 389-399 ◽  
Author(s):  
Man Huang ◽  
Yong Kang ◽  
Xiao-chuan Wang ◽  
Yi Hu ◽  
Can Cai

Author(s):  
J. M. Tanko

During the 1990s, the chemical industry has focused on ways to reduce and prevent pollution caused by chemical synthesis and manufacturing. The goal of this approach is to modify existing reaction conditions and/or to develop new chemistries that do not require the use of toxic reagents or solvents, or that do not produce toxic by-products. The terms “environmentally benign synthesis and processing” and “green chemistry” have been coined to describe this approach where the environmental impact of a process is as important an issue as reaction yield, efficiency, or cost. Most chemical reactions require the use of a solvent that may serve several functions in a reaction: for example, ensuring homogeneity of the reactants, facilitating heat transfer, extraction of a product (or by-product), or product purification via chromatography. However, because the solvent is only indirectly involved in a reaction (i.e., it is not consumed), its disposal becomes an important issue. Thus, one obvious approach to “green chemistry” is to identify alternative solvents that are nontoxic and/or environmentally benign. Supercritical carbon dioxide (sc CO2) has been identified as a solvent that may be a viable alternative to solvents such as CCl4, benzene, and chloroflurocarbons (CFCs), which are either toxic or damaging to the environment. The critical state is achieved when a substance is taken above its critical temperature and pressure (Tc, Pc). Above this point on a phase diagram, the gas and liquid phases become indistinguishable. The physical properties of the supercritical state (e.g., density, viscosity, solubility parameter, etc.) are intermediate between those of a gas and a liquid, and vary considerably as a function of temperature and pressure. The interest in sc CO2 specifically is related to the fact that CO2 is nontoxic and naturally occurring. The critical parameters of CO2 are moderate (Tc = 31 °C, Pc = 74 bar), which means that the supercritical state can be achieved without a disproportionate expenditure of energy. For these two reasons, there is a great deal of interest in sc CO2 as a solvent for chemical reactions. This chapter reviews the literature pertaining to free-radical reactions in sc CO2 solvent.


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