Experimental and modeling study of pyrolysis of coal, biomass and blended coal-biomass particles

This paper reports a combined experimental and numerical investigation of the pyrolysis characteristics of coal, biomass, and coal-biomass blends. Coal and straw were grounded and pressed into spherical particles with diameter of 8 mm, and blended coal-straw particles were prepared through mixing pulverized coal and straw before pressed into particles. Sample particles were suspended in the center of a single-particle reactor system and devolatilized under different temperatures. The analysis of the time history of the residual mass of particles of coal, straw, and coal-straw blends suggested an absence of synergistic effect between the coal and the straw. In addition, a one-dimensional, time-dependent particle model; based on the chemical percolation devolatilization (CPD) and bio-CPD models; was developed to simulate the pyrolysis of coal and straw particles. The model predictions agree will with the measured data. An extended CPD model was proposed to explain the co-pyrolysis characteristics of coal-biomass blends. Encouraging agreement was found between the predicted and the experimental results of pyrolysis of coal-straw blends.