Pyrolysis and gasification of coal at high temperatures

Coals of different ranks will be pyrolyzed in a microscope hot-stage reactor using inert and reacting atmosphere. The macropore structure of the produced chars will be characterized using video microscopy and digital image processing techniques to obtain pore size distributions. Comparative studies will quantify the effect of pyrolysis conditions (heating rates, final heat treatment temperatures, particle size and inert or reacting atmosphere) on the pore structure of the devolatilized chars. The devolatilized chars will be gasified in the regime of strong intraparticle diffusional limitations using O{sub 2}/N{sub 2} and O{sub 2}/H{sub 2}O/N{sub 2}2 mixtures. Constant temperature and programmed-temperature experiments in a TCA will be used for these studies. Additional gasification experiments performed in the hot-stage reactor will be videotaped and selected images will be analyzed to obtain quantitative data on particle shrinkage and fragmentation