Attrition of dolomitic lime in a fluidized-bed reactor at high temperatures

Results of an experimental study on the rate of attrition of lime catalyst/sorbent in a high-temperature, turbulent fluidized bed with quartz sand are presented. Batch measurements were conducted at 850°C in an electrically heated gasification reactor of the inner diameter of 5.1 cm with three samples of high-grade dolomitic lime of the particle size 450 μm, 715 μm, and 1060 μm, respectively. In addition to the influence of the particle size, the effect of operating (elapsed) time was investigated at different superficial gas velocities. Assuming that the attrition rate decreases exponentially with time, a simple mechanistic model, enabling the correlation of the measured experimental data, was developed. The course of the lime particles attrition is described as a function of the elapsed time, excess gas velocity, and particle size. The presented approach and the results might be applicable for the attrition of high-grade dolomitic lime, particularly in fluidized gasification of biomass.