Experimental Study On Permeability Improvement Of Coal Samples By Using Fenton Reagent

In coal mining,gas disaster is always the main disasters to threaten the security of coal mine.But it also has a high extraction and utilization value as a kind of clean and efficient energy.The low permeability characteristic of coal reservoirs in China determines that if the CBM was mined in a large-scale,it must be conducted coal reservoir reconstruction,increased its permeability.So far,the physical measures were often used to increase the permeability of coal reservoir,such as,hydrofracture,Hydraulic slotting,hole enlarging with high water jet,deep-hole controlled pre-cracking explosion etc,if used the chemical means to improve the permeability of coal,it will have an important significance to the exploitation and utilization of the low permeability coalbed methane in China.In this paper,we studied the oxidative degradation of polycyclic aromatic hydrocarbons by Fenton reagent and experiments of using Fenton reagent to deal with the anthracite,the changing characteristics of coal surface,pore structure and permeability before and after using Fenton reagent were concluded.The main conclusions were as follows in this paper:?1?The experiment result of using Fenton reagent to oxide the polycyclic aromatic hydrocarbons molecules anthracene and phenanthrene shows that Fenton reagent has a high oxidation removal rate to small molecules anthracene and phenanthrene,the removal rate of anthracene and phenanthrene were 68.51% and 75.11%;Using GC-MS and Liquid chromatography instrument to analysis the solid materials and filtrate after reaction,the results shows that the solid materials were unreacted anthracene and phenanthrene,but the filtrate after reaction of anthracene and phenanthrene generated new materials,which confirmed the reaction of Fenton reagent with the polycyclic aromatic hydrocarbons.?2?The test results of the SEM and MIP shows that the oxidation corrosion pores were formed on the surface of the coal sample,the porosity and pore volume of coal sample increased,the ratio of macropore and mesopore increased,the specific surface area of foraminulum and micropore decreased,the connectivity between holes and cracks were enhanced after using Fenton reagent,increased the gas migration channel which was conducive to the gas seepage.?3?By compared the coal samples' permeability results after treated with distilled water and Fenton reagent,came to the conclusion that Fenton reagent had a good effect on improving the coal samples' permeability.By compared the effect of Fenton reagent under different c?H2O2?and c(Fe²⁺),came to the conclusion that when c?H2O2?=100mmol/L,c(Fe²⁺)=5mmol/L,pH=3,Fenton reagent had the best effect and the coal samples' permeability increased 210.84%.