Precipitation Mechanism And Production Characteristics Of The Main Gas During Pyrolysis Of Different Metamorphic Deformation Coals

The main gas phase product is methane during the process of coal pyrolysis, in this work, we have a study on the influence of metamorphic deformation during pyrolysis with the experimental data of Ro,max, proximate and ultimate analysis, XRD, and 13 C NMR, the main conclusions were as follows,(1) For the low metamorphic degree of tectonic deformed coals, due to the influence of tectonic stress, both the carbon atoms top wire spacing d002 and La/Lc have a small decrease trend with the increase of deformation degree, both the middle and high metamorphic degree of tectonic deformed coals have a similar trend. From brittle deformed coals to ductile deformed coals, faH(protonation aromatic carbon) and faB(bridge aromatic carbon) increasing with the augmentation of the tectonic deformation, while faS(collateral aromatic carbon) and faO(oxygen instead of aromatic carbon) were reduce.(2) The adsorption simulation calculation of methane indicated that the methane adsorption capacity of coal effects on stress by different deformation properties and strength were not unique, there is a certain influence on both deformation properties and strength, especially at low temperatures(e.g., 30?).(3) The pyrolysis experiments of different metamorphic deformed coal showed, CH4 and CO2 were significantly lower than the same metamorphic grade of tectonic deformed coals, strong tectonic deformation coals significantly lower than the weak tectonic deformation of coals, the ductile tectonic deformed coals significantly lower than the brittle tectonic deformed coals, it was concluded that the boost of tectonic stress can lead to evolutionary phase of coals in advance, and also speed up the precipitation rate of small molecule gases.(4) Because of tectonic deformation the tectonic deformed coals of the pyrolysis precipitation amount of CH4 and CO2 were lower than undeformed coals, and the ductile coals were even less, the strong tectonic deformation like a strong magmatism which brought about the formation of oxygen containing functional group and the side chain et al. largely fall off in the early years.