Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high-temperature furnace (HITAF): Volume 3. Final report

Testing of an atmospheric circulating bed pyrolyzer was done at Southern Illinois University. A variety of experiments have been conducted in a laboratory scale pyrolyzer with coal input flow rates from 2 to 6 lb/h. three feed coal particle sizes, corresponding to a nominal -40 mesh, -30 mesh and -18 mesh were used. The limestone used in the tests was a Genstar limestone. Parameters investigated in the tests include the influence of superficial velocity, temperature and coal-air mass ratios. Char particle size distributions under various test conditions have been measured and the char composition determined. Fuel gas composition, yields and heating values have been investigated. Char morphology has been studied using scanning electron microscopy. Char reactivity for selected samples has been measures, and the influence of feed coal size, bed temperature and superficial velocity has been determined. Material balance calculations have been performed and found to be in very good agreement. Energy audit calculations for the process have been made to investigate the flow of energy and to estimate the losses during the process. Full details of the data, results obtained and conclusions drawn are presented