| Coalbed methane is a harmful gas that threatens the safe production of coal mines..Coalbed methane mainly exists in the coal body in an adsorbed state.The outburst prevention measures in the actual engineering application include advance discharge,coal seam water injection and other measures.However,most of the coal seams in our country have poor water pereability,which makes it difficult for the coal to be uniformly wetted,and thus has no significant effect on the gas concentration overrun.Therefore,it is of great significance to find an environment-friendly solution to promote the uniform wetting of coal and to study its influence on the adsorption and analytical performance of coalbed methane gas,so as to achieve the ideal goal of protecting the ecological environment and preventing the gas dynamic disaster accidents.In this paper,through the combination of theoretical analysis and experimental research,three natural non-ionic biosurfactants,tea saponin,sapindus,sucrose esters,and a natural anionic bio surfactant lipopeptide were screened for this experiment.Based on surface tension,contact angle and other basic experiments,a series of wetting and adsorption parameters such as spreading coefficient and surface free energy were measured.Based on the basic experimental parameters,the best monomer solution was screened and mixed to obtain solutions F1～F7.Through comprehensive comparison and analysis of the parameters of wetting and adsorption,two environmentally friendly wetting accelerators,F1 solution and lipopeptide solution,which have the best performance and are completely biodegradable and have no irritating effect on the organism,were selected.Then,using the WT-1 gas release initial speed tester,BSD-PH series automatic high pressure gas adsorption/desorption analyzer and other experimental platforms,the raw coal sample,water injection coal sample,F1 solution injection coal sample and lipopeptide injection solution coal Experiments on initial gas release rate and high-pressure gas adsorption and desorption performance were conducted on the sample.The main experimental results showed that:(1)The ΔP value of the coal sample injected with liquid was significantly reduced.Compared with the raw coal,the AP value of water injection decreased by 52.38%,and the ΔP of F1 The value decreased by 54.76%,and the ΔP value of injection Z decreased by 61.9%;(2)the injection of liquid can reduce the gas adsorption capacity of coal.Compared with the original coal sample,the water injection coal sample has an adsorption reduction of 16.97%;the injection of the F1 solution coal sample has a reduction of 35.35%compared to the original coal sample;and the injection of the Z solution solution coal sample has an adsorption reduction of 42.77%compared with the original coal sample.The experimental results show that compared with water,the surfactant effectively reduces the surface tension of the contact surface between the solution and the coal sample,and the solution with the surfactant is easier to wet and spread on the surface of the coal sample,so that the solution can enter the coal body.It is deeper and wider,and can penetrate the coal body more than water,which has a significant impact on coal gas adsorption and desorption performance.The experimental results can provide a theoretical basis for the application of biological surfactants in coal mines,and also provide a new way for coal seam water injection to control mine gas outburst.Figure[28]Table[17]Reference[106]... |
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