The influences of fractal pore structure in coal reservoir on coalbed methane(CBM) migration were analyzed in detail by coupling theoretical models and numerical methods.Different types of fractals were generated base...The influences of fractal pore structure in coal reservoir on coalbed methane(CBM) migration were analyzed in detail by coupling theoretical models and numerical methods.Different types of fractals were generated based on the construction thought of the standard Menger Sponge to model the 3D nonlinear coal pore structures.Then a correlation model between the permeability of fractal porous medium and its pore-size-distribution characteristics was derived using the parallel and serial modes and verified by Lattice Boltzmann Method(LBM).Based on the coupled method,porosity(ф),fractal dimension of pore structure(Db),pore size range(rmin,rmax) and other parameters were systematically analyzed for their influences on the permeability(ф) of fractal porous medium.The results indicate that:① the channels connected by pores with the maximum size(rmax) dominate the permeability,approximating in the quadratic law;② the greater the ratio of r max and r min is,the higher is;③ the relationship between D b and follows a negative power law model,and breaks into two segments at the position where Db ≌2.5.Based on the results above,a predicting model of fractal porous medium permeability was proposed,formulated as k=cfrnmax,where C and n(approximately equal to 2) are constants and f is an expression only containing parameters of fractal pore structure.In addition,the equivalence of the new proposed model for porous medium and the Kozeny-Carman model k=Crn was verified at Db =2.0.展开更多
Chemical synthetic residual is one of the solid wastes generated from pharmaceutical industry.The pyrolysis and combustion characteristics of chemical synthesis residual were investigated using a thermogravimetric ana...Chemical synthetic residual is one of the solid wastes generated from pharmaceutical industry.The pyrolysis and combustion characteristics of chemical synthesis residual were investigated using a thermogravimetric analyser coupled with Fourier transform infrared spectroscopy(TG-FTIR)in this study.The processes of pyrolysis and combustion can be divided into three stages.The average weight loss rate of pyrolysis process at low temperature was higher than that of combustion.The kinetic parameters of chemical synthesis residual during pyrolysis and combustion were calculated based on the TG results.Acetic acid and 4-aminophenol were the main evolved matter observed in the pyrolysis process.The emission characteristics of combustion at low temperature were similar to that of the pyrolysis,while CO2 was found as the major gaseous product at high temperature.A high temperature about 850°C is needed to make sure the complete combustion of chemical synthesis residual.展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.41102093&41072153)CBM Union Foundation of Shanxi Province (Grant No.2012012002)Doctoral Scientific Foundation of Henan Polytechnic University(Grant No.648706)
文摘The influences of fractal pore structure in coal reservoir on coalbed methane(CBM) migration were analyzed in detail by coupling theoretical models and numerical methods.Different types of fractals were generated based on the construction thought of the standard Menger Sponge to model the 3D nonlinear coal pore structures.Then a correlation model between the permeability of fractal porous medium and its pore-size-distribution characteristics was derived using the parallel and serial modes and verified by Lattice Boltzmann Method(LBM).Based on the coupled method,porosity(ф),fractal dimension of pore structure(Db),pore size range(rmin,rmax) and other parameters were systematically analyzed for their influences on the permeability(ф) of fractal porous medium.The results indicate that:① the channels connected by pores with the maximum size(rmax) dominate the permeability,approximating in the quadratic law;② the greater the ratio of r max and r min is,the higher is;③ the relationship between D b and follows a negative power law model,and breaks into two segments at the position where Db ≌2.5.Based on the results above,a predicting model of fractal porous medium permeability was proposed,formulated as k=cfrnmax,where C and n(approximately equal to 2) are constants and f is an expression only containing parameters of fractal pore structure.In addition,the equivalence of the new proposed model for porous medium and the Kozeny-Carman model k=Crn was verified at Db =2.0.
基金supported by the National Key Research and Development Program of China (2018YFF0215001, 2017YFC0703100)the Innovative Research Groups of the National Natural Science Foundation of China (51621005)+1 种基金the National Natural Science Foundation of China (51676172)the Fundamental Research Funds for the Central Universities (2016FZA4010)
文摘Chemical synthetic residual is one of the solid wastes generated from pharmaceutical industry.The pyrolysis and combustion characteristics of chemical synthesis residual were investigated using a thermogravimetric analyser coupled with Fourier transform infrared spectroscopy(TG-FTIR)in this study.The processes of pyrolysis and combustion can be divided into three stages.The average weight loss rate of pyrolysis process at low temperature was higher than that of combustion.The kinetic parameters of chemical synthesis residual during pyrolysis and combustion were calculated based on the TG results.Acetic acid and 4-aminophenol were the main evolved matter observed in the pyrolysis process.The emission characteristics of combustion at low temperature were similar to that of the pyrolysis,while CO2 was found as the major gaseous product at high temperature.A high temperature about 850°C is needed to make sure the complete combustion of chemical synthesis residual.
