Abstract:

The blended coals of anthracite and bituminous coal were pyrolyzed in a tubular electric furnace in an inert atmosphere at different final temperatures.The coal chars were tested by means of the adsorption of nitrogen at a low temperature to study the surface structure.From the analysis of isotherm adsorption, it was shown that coal chars had continuous and complete pore structures.The presence of amorphous pores perhaps led to the phenomenon of non-dosure of adsorption hysteresis loop.Bituminous coal and A1B1 blended coal char had the same rule that the specific surface area increased with increasing pyrolysis temperature up to 700℃ and then decreased.When the pyrolysis temperature was 1000℃, the micro-pore volume of blended coal chars increased with increasing blend ratio of bituminous coal; however, when the blend ratio was higher than 2/3, the micro-pore volume of blended coal chars decreased.A1B2 blended coal had the maximum micro-pore volume and specific surface area.The fractal analysis showed that micro-pore ratio had close relation to fractal dimension.The variation of surface structure revealed the independence and interaction of parent coals during the pyrolysis of blended coals.