Study On The Changes Of Oxygen Containing Functional Group And Pore Structure During Oil Shale Semi-coke Combustion

Oil shale semicoke,the solid residues produced from the process of oil refining from oil shale,is huge in quantities and possesses certain calorific value and contains large of pollutants of phenolic,sulfide,polycyclic aromatics,which will damage to the environment.Combustion to oil shale semicoke is an effective treatment method for the issue.Beginningfrom oxygen-containing functional group and pore structure,this paper analyzes the rule of variation of the shale semicoke oxygen containing functional groups and pore structure in the process of combustion,thus further understanding of the shale semicoke surface microcosmic structure change in the combustion process.In the paper,the main research contents are displayed as follows:First of all,on the basis of thermogravimetric experiment,the combustion characteristic and TG-DTG curve of oil shale semicoke were studied,Results showed that increasing the heating rate can hamper the oil shale semicoke catch fire and delay it combustion completely in a certain extent,to promote the oil shale semicoke combustion,In three kinds of oil shale semicoke,the comprehensive combustion characteristic of YJSC is best,WQSC worst;LKSC in the middle.In air atmosphere,WQSC?LKSC and YJSC were used in the tube furnace combustion experiment for preparation of different final temperature of combustion ash samplesand the surface functional groups of samples were analyzed based on Portable-Fourier transform infrared(FTIR)spectrometer.Results indicate that the infrared spectra structure was similar,and only part of the absorption peak intensity differences,the area of hydroxyl vibration absorptionwas very weak and there was no obvious carboxyl vibration absorption.Phenol,alcohol,ether,ester C-O key relative content increased while hydroxyl decreased during combustion,the carbonyl content showed a fluctuated pattern.At the same time in the burning process aromatic skeleton vibration weakened and fat hydrocarbon decreased in continuous oxidation disappear.On the foundation of the tube furnaceexperiment,the nitrogen isothermal adsorptiondesorption method were conducted to investigate the variation of surface pore structure characteristics of the oil shale semicoke ash samples which obtained at different terminal temperature of combustion and the fractal dimension was used to quantitatively describe the complexity of the ash samples surface morphology.The results showed that the pores in the oil shale semicoke were mainly seam type pores,and mainly microporous and mesopores in number.With the deepening of the combustion,the specific surface area firstly increased and then gradually decreased.And the contribution of micropore and mesopores to the total specific surface area was the largest.That WQSC and LKSC in pore characteristics changed relatively uniform in the combustion process was well presented by the fractal dimension obtained by the regression of the FHH equation.