关键词: 油砂, 吸附, 表面, 热解, 分形维数

Abstract: The nitrogen isothermal adsorption-desorption method and scanning electron microscope were conducted to investigate the variation of the semi-coke surface characteristics in the course of the Indonesian oil sand pyrolysis in this research，and the fractal dimension was used to quantitatively describe the complexity of the semi-coke surface morphology. The results showed that the trends of the char BET surface area and the pore volume towards the final retorting temperature were similar，firstly increasing and then decreasing. The fractal feature of the semi-coke particles internal porosity could be well illustrated by the fractal dimension obtained by the regression of the FHH equation. The tendency of the fractal dimension varied in different temperature ranges，due to the alternating impact of multiple effects，including the devolatilization，the plastic deformation，the escape of gas products and the recondensation of oils. The semi-coke surface pore structure characteristics can be directly observed through the SEM，and the trends of the box-counting fractal dimension by the application of Matlab programming to the SEM picture and the FHH fractal dimension were proximately consistent.

Key words: oil sands, adsorption, surface, pyrolysis, fractal dimension